Sample records for soil drainage water
-
Water Drainage from Unsaturated Soils in a Centrifuge Permeameter
Ornelas, G.; McCartney, J.; Zhang, M.
2013-12-01
This study involves an analysis of water drainage from an initially saturated silt layer in a centrifuge permeameter to evaluate the hydraulic properties of the soil layer in unsaturated conditions up to the point where the water phase becomes discontinuous. These properties include the soil water retention curve (SWRC) and the hydraulic conductivity function (HCF). The hydraulic properties of unsaturated silt are used in soil-atmosphere interaction models that take into account the role of infiltration and evaporation of water from soils due to atmospheric interaction. These models are often applied in slope stability analyses, landfill cover design, aquifer recharge analyses, and agricultural engineering. The hydraulic properties are also relevant to recent research concerning geothermal heating and cooling, as they can be used to assess the insulating effects of soil around underground heat exchangers. This study employs a high-speed geotechnical centrifuge to increase the self-weight of a compacted silt specimen atop a filter plate. Under a centrifuge acceleration of N times earth's gravity, the concept of geometric similitude indicates that the water flow process in a small-scale soil layer will be similar to those in a soil layer in the field that is N times thicker. The centrifuge acceleration also results in an increase in the hydraulic gradient across the silt specimen, which causes water to flow out of the pores following Darcy's law. The drainage test was performed until the rate of liquid water flow out of the soil layer slowed to a negligible level, which corresponds to the transition point at which further water flow can only occur due to water vapor diffusion following Fick's law. The data from the drainage test in the centrifuge were used to determine the SWRC and HCF at different depths in the silt specimen, which compared well with similar properties defined using other laboratory tests. The transition point at which liquid water flow stopped (and
-
Zhang, T Q; Tan, C S; Zheng, Z M; Welacky, T W; Reynolds, W D
2015-03-01
Adoption of waste-derived soil conditioners and refined water management can improve soil physical quality and crop productivity of fine-textured soils. However, the impacts of these practices on water quality must be assessed to ensure environmental sustainability. We conducted a study to determine phosphorus (P) loss in tile drainage as affected by two types of soil conditioners (yard waste compost and swine manure compost) and water table management (free drainage and controlled drainage with subirrigation) in a clay loam soil under corn-soybean rotation in a 4-yr period from 1999 to 2003. Tile drainage flows were monitored and sampled on a year-round continuous basis using on-site auto-sampling systems. Water samples were analyzed for dissolved reactive P (DRP), particulate P (PP), and total P (TP). Substantially greater concentrations and losses of DRP, PP, and TP occurred with swine manure compost than with control and yard waste compost regardless of water table management. Compared with free drainage, controlled drainage with subirrigation was an effective way to reduce annual and cumulative losses of DRP, PP, and TP in tile drainage through reductions in flow volume and P concentration with control and yard waste compost but not with swine manure compost. Both DRP and TP concentrations in tile drainage were well above the water quality guideline for P, affirming that subsurface loss of P from fine-textured soils can be one critical source for freshwater eutrophication. Swine manure compost applied as a soil conditioner must be optimized by taking water quality impacts into consideration. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.
-
Tong, Juxiu; Hu, Bill X; Yang, Jinzhong; Zhu, Yan
2016-06-01
The mixing layer theory is not suitable for predicting solute transfer from initially saturated soil to surface runoff water under controlled drainage conditions. By coupling the mixing layer theory model with the numerical model Hydrus-1D, a hybrid solute transfer model has been proposed to predict soil solute transfer from an initially saturated soil into surface water, under controlled drainage water conditions. The model can also consider the increasing ponding water conditions on soil surface before surface runoff. The data of solute concentration in surface runoff and drainage water from a sand experiment is used as the reference experiment. The parameters for the water flow and solute transfer model and mixing layer depth under controlled drainage water condition are identified. Based on these identified parameters, the model is applied to another initially saturated sand experiment with constant and time-increasing mixing layer depth after surface runoff, under the controlled drainage water condition with lower drainage height at the bottom. The simulation results agree well with the observed data. Study results suggest that the hybrid model can accurately simulate the solute transfer from initially saturated soil into surface runoff under controlled drainage water condition. And it has been found that the prediction with increasing mixing layer depth is better than that with the constant one in the experiment with lower drainage condition. Since lower drainage condition and deeper ponded water depth result in later runoff start time, more solute sources in the mixing layer are needed for the surface water, and larger change rate results in the increasing mixing layer depth.
-
Drainage water management combined with cover crop enhances reduction of soil phosphorus loss.
Zhang, T Q; Tan, C S; Zheng, Z M; Welacky, T; Wang, Y T
2017-05-15
Integrating multiple practices for mitigation of phosphorus (P) loss from soils may enhance the reduction efficiency, but this has not been studied as much as individual ones. A four-year study was conducted to determine the effects of cover crop (CC) (CC vs. no CC, NCC) and drainage water management (DWM) (controlled drainage with sub-irrigation, CDS, vs. regular free tile drainage, RFD) and their interaction on P loss through both surface runoff (SR) and tile drainage (TD) water in a clay loam soil of the Lake Erie region. Cover crop reduced SR flow volume by 32% relative to NCC, regardless of DWM treatment. In contrast, CC increased TD flow volume by 57 and 9.4% with CDS and RFD, respectively, compared to the corresponding DWM treatment with NCC. The total (SR+TD) field water discharge volumes were comparable amongst all the treatments. Cover crop reduced flow-weighted mean (FWM) concentrations of particulate P (PP) by 26% and total P (TP) by 12% in SR, while it didn't affect the FWM dissolved reactive P (DRP) concentration, regardless of DWM treatments. Compared with RFD, CDS reduced FWM DRP concentration in TD water by 19%, while CC reduced FWM PP and TP concentrations in TD by 21 and 17%, respectively. Total (SR+TD) soil TP loss was the least with CDS-CC followed by RFD-CC, CDS-NCC, and RFD-NCC. Compared with RFD-NCC, currently popular practice in the region, total TP loss was reduced by 23% with CDS-CC. The CDS-CC system can be an effective practice to ultimately mitigate soil P loading to water resource. Copyright © 2017 Elsevier B.V. All rights reserved.
-
Directory of Open Access Journals (Sweden)
Antônio Ocimar Manzi
2011-04-01
Full Text Available Central Amazonian rainforest landscape supports a mosaic of tall terra firme rainforest and ecotone campinarana, riparian and campina forests, reflecting topography-induced variations in soil, nutrient and drainage conditions. Spatial and temporal variations in litter decomposition, soil and groundwater chemistry and soil CO2 respiration were studied in forests on sandy soils, whereas drought sensitivity of poorly-drained valley soils was investigated in an artificial drainage experiment. Slightly changes in litter decomposition or water chemistry were observed as a consequence of artificial drainage. Riparian plots did experience higher litter decomposition rates than campina forest. In response to a permanent lowering of the groundwater level from 0.1 m to 0.3 m depth in the drainage plot, topsoil carbon and nitrogen contents decreased substantially. Soil CO2 respiration decreased from 3.7±0.6 µmol m-2 s-1 before drainage to 2.5±0.2 and 0.8±0.1 µmol m-2 s-1 eight and 11 months after drainage, respectively. Soil respiration in the control plot remained constant at 3.7±0.6 µmol m-2 s-1. The above suggests that more frequent droughts may affect topsoil carbon and nitrogen content and soil respiration rates in the riparian ecosystem, and may induce a transition to less diverse campinarana or short-statured campina forest that covers areas with strongly-leached sandy soil.
-
Reducing phosphorus loss in tile water with managed drainage in a claypan soil.
Nash, Patrick R; Nelson, Kelly A; Motavalli, Peter P; Nathan, Manjula; Dudenhoeffer, Chris
2015-03-01
Installing subsurface tile drain systems in poorly drained claypan soils to improve corn ( L.) yields could potentially increase environmental phosphorus (P) loss through the tile drainage system. The objectives of the study were to quantify the average concentration and loss of ortho-P in tile drain water from a claypan soil and to determine whether managed subsurface drainage (MD) could reduce ortho-P loss in tile water compared with free subsurface drainage (FD). Flow-weighted ortho-P concentration in the tile water was significantly lower with MD (0.09 mg L) compared with that of FD (0.15 mg L). Ortho-P loss in the tile water of this study was reduced with MD (36 g ha) by 80% compared with FD (180 g ha). Contrary to previous research, reduced ortho-P loss observed over the 4-yr study was not solely due to the reduced amount of water drained annually (63%) with MD compared with FD. During the spring period, when flow was similar between MD and FD, the concentration of ortho-P in the tile water generally was lower with MD compared with FD, which resulted in significantly less ortho-P loss with MD. We speculate that MD's ability to conserve water during the dry summer months increased corn's uptake of water and P, which reduced the amount of P available for leaching loss in the subsequent springs. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.
-
Zhang, T Q; Tan, C S; Wang, Y T; Ma, B L; Welacky, T
2017-02-15
Recent ascertainment of tile drainage a predominant pathway of soil phosphorus (P) loss, along with the rise in concentration of soluble P in the Lake Erie, has led to a need to re-examine the impacts of agricultural practices. A three-year on-farm study was conducted to assess P loss in tile drainage water under long-term conventional- (CT) and non-tillage (NT) as influenced by yard waste leaf compost (LC) application in a Brookston clay loam soil. The effects of LC addition on soil P loss in tile drainage water varied depending on P forms and tillage systems. Under CT, dissolved reactive P (DRP) loss with LC addition over the study period was 765g P ha -1 , 2.9 times higher than CT without LC application, due to both a 50% increase in tile drainage flow volume and a 165% increase in DRP concentration. Under NT, DRP loss in tile drainage water with LC addition was 1447gPha -1 , 5.3 times greater than that for NT without LC application; this was solely caused by a 564% increase in DRP concentration. However, particulate P loads in tile drainage water with LC application remained unchanged, relative to non-LC application, regardless of tillage systems. Consequently, LC addition led to an increase in total P loads in tile drainage water by 57 and 69% under CT and NT, respectively. The results indicate that LC application may become an environmental concern due to increased DRP loss, particularly under NT. Crown Copyright © 2016. Published by Elsevier B.V. All rights reserved.
-
How internal drainage affects evaporation dynamics from soil surfaces ?
Or, D.; Lehmann, P.; Sommer, M.
2017-12-01
Following rainfall, infiltrated water may be redistributed internally to larger depths or lost to the atmosphere by evaporation (and by plant uptake from depths at longer time scales). A large fraction of evaporative losses from terrestrial surfaces occurs during stage1 evaporation during which phase change occurs at the wet surface supplied by capillary flow from the soil. Recent studies have shown existence of a soil-dependent characteristic length below which capillary continuity is disrupted and a drastic shift to slower stage 2 evaporation ensues. Internal drainage hastens this transition and affect evaporative losses. To predict the transition to stage 2 and associated evaporative losses, we developed an analytical solution for evaporation dynamics with concurrent internal drainage. Expectedly, evaporative losses are suppressed when drainage is considered to different degrees depending on soil type and wetness. We observe that high initial water content supports rapid drainage and thus promotes the sheltering of soil water below the evaporation depth. The solution and laboratory experiments confirm nonlinear relationship between initial water content and total evaporative losses. The concept contributes to establishing bounds on regional surface evaporation considering rainfall characteristics and soil types.
-
Soil and Soil Water Relationships
Easton, Zachary M.; Bock, Emily
2017-01-01
Discusses the relationships between soil, water and plants. Discusses different types of soil, and how these soils hold water. Provides information about differences in soil drainage. Discusses the concept of water balance.
-
Pressure Jumps during Drainage in Macroporous Soils
DEFF Research Database (Denmark)
Soto, Diego; Paradelo Pérez, Marcos; Corral, A
2018-01-01
Tensiometer readings obtained at high resolution during drainage of structured soil columns revealed pressure jumps with long range correlations and burst sequences with a hierarchical structure. The statistical properties of jumps are similar to Haines jumps described in invasion percolation...... processes at pore scale, but they are much larger in amplitude and duration. Pressure jumps can result from transient redistribution of water potential in internal regions of soil and can be triggered during drainage by capillary displacements at the scale of structural pores....
-
Controls on deep drainage beneath the root soil zone in snowmelt-dominated environments
Hammond, J. C.; Harpold, A. A.; Kampf, S. K.
2017-12-01
Snowmelt is the dominant source of streamflow generation and groundwater recharge in many high elevation and high latitude locations, yet we still lack a detailed understanding of how snowmelt is partitioned between the soil, deep drainage, and streamflow under a variety of soil, climate, and snow conditions. Here we use Hydrus 1-D simulations with historical inputs from five SNOTEL snow monitoring sites in each of three regions, Cascades, Sierra, and Southern Rockies, to investigate how inter-annual variability on water input rate and duration affects soil saturation and deep drainage. Each input scenario was run with three different soil profiles of varying hydraulic conductivity, soil texture, and bulk density. We also created artificial snowmelt scenarios to test how snowmelt intermittence affects deep drainage. Results indicate that precipitation is the strongest predictor (R2 = 0.83) of deep drainage below the root zone, with weaker relationships observed between deep drainage and snow persistence, peak snow water equivalent, and melt rate. The ratio of deep drainage to precipitation shows a stronger positive relationship to melt rate suggesting that a greater fraction of input becomes deep drainage at higher melt rates. For a given amount of precipitation, rapid, concentrated snowmelt may create greater deep drainage below the root zone than slower, intermittent melt. Deep drainage requires saturation below the root zone, so saturated hydraulic conductivity serves as a primary control on deep drainage magnitude. Deep drainage response to climate is mostly independent of soil texture because of its reliance on saturated conditions. Mean water year saturations of deep soil layers can predict deep drainage and may be a useful way to compare sites in soils with soil hydraulic porosities. The unit depth of surface runoff often is often greater than deep drainage at daily and annual timescales, as snowmelt exceeds infiltration capacity in near-surface soil layers
-
Agricultural drainage water quality
International Nuclear Information System (INIS)
Madani, A.; Gordon, R.
2002-01-01
'Full text:' Agricultural drainage systems have been identified as potential contributors of non-point source pollution. Two of the major concerns have been with nitrate-nitrogen (NO3 - -N) concentrations and bacteria levels exceeding the Maximum Acceptable Concentration in drainage water. Heightened public awareness of environmental issues has led to greater pressure to maintain the environmental quality of water systems. In an ongoing field study, three experiment sites, each with own soil properties and characteristics, are divided into drainage plots and being monitored for NO3 - -N and fecal coliforms contamination. The first site is being used to determine the impact of the rate of manure application on subsurface drainage water quality. The second site is being used to determine the difference between hog manure and inorganic fertilizer in relation to fecal coliforms and NO3-N leaching losses under a carrot rotation system. The third site examines the effect of timing of manure application on water quality, and is the only site equipped with a surface drainage system, as well as a subsurface drainage system. Each of the drains from these fields lead to heated outflow buildings to allow for year-round measurements of flow rates and water samples. Tipping buckets wired to data-loggers record the outflow from each outlet pipe on an hourly basis. Water samples, collected from the flowing drains, are analyzed for NO3 - -N concentrations using the colorimetric method, and fecal coliforms using the Most Probable Number (MPN) method. Based on this information, we will be able better positioned to assess agricultural impacts on water resources which will help towards the development on industry accepted farming practices. (author)
-
Saadat, Samaneh; Bowling, Laura; Frankenberger, Jane; Kladivko, Eileen
2018-01-01
Long records of continuous drain flow are important for quantifying annual and seasonal changes in the subsurface drainage flow from drained agricultural land. Missing data due to equipment malfunction and other challenges have limited conclusions that can be made about annual flow and thus nutrient loads from field studies, including assessments of the effect of controlled drainage. Water table depth data may be available during gaps in flow data, providing a basis for filling missing drain flow data; therefore, the overall goal of this study was to examine the potential to estimate drain flow using water table observations. The objectives were to evaluate how the shape of the relationship between drain flow and water table height above drain varies depending on the soil hydraulic conductivity profile, to quantify how well the Hooghoudt equation represented the water table-drain flow relationship in five years of measured data at the Davis Purdue Agricultural Center (DPAC), and to determine the impact of controlled drainage on drain flow using the filled dataset. The shape of the drain flow-water table height relationship was found to depend on the selected hydraulic conductivity profile. Estimated drain flow using the Hooghoudt equation with measured water table height for both free draining and controlled periods compared well to observed flow with Nash-Sutcliffe Efficiency values above 0.7 and 0.8 for calibration and validation periods, respectively. Using this method, together with linear regression for the remaining gaps, a long-term drain flow record for a controlled drainage experiment at the DPAC was used to evaluate the impacts of controlled drainage on drain flow. In the controlled drainage sites, annual flow was 14-49% lower than free drainage.
-
Directory of Open Access Journals (Sweden)
Cesar Perez-Valdivia
2017-12-01
Full Text Available Study region: Prairie Pothole Region of North America. Study focus: The Prairie Pothole Region of North America has experienced extensive wetland drainage, potentially impacting peak flows and annual flow volumes. Some of this drainage has occurred in closed basins, possibly impacting lake water levels of these systems. In this study we investigated the potential impact of wetland drainage on peak flows and annual volumes in a 2242Â km2 watershed located in southeastern Saskatchewan (Canada using the Soil Water Assessment Tool (SWAT model. New hydrological insights: The SWAT model, which had been calibrated and validated at daily and monthly time steps for the 1997â2009 period, was used to assess the impact of wetland drainage using three hypothetical scenarios that drained 15, 30, and 50% of the non-contributing drainage area. Results of these simulations suggested that drainage increased spring peak flows by about 50, 79 and 113%, respectively while annual flow volumes increased by about 43, 68, and 98% in each scenario. Years that were wetter than normal presented increased peak flows and annual flow volumes below the average of the simulated period. Alternatively, summer peak flows presented smaller increases in terms of percentages during the simulated period. Keywords: Soil Water Assessment Tool (SWAT, Wetland drainage, Peak flow, Annual volume, Prairie Pothole Region
-
Tile Drainage Expansion Detection using Satellite Soil Moisture Dynamics
Jacobs, J. M.; Cho, E.; Jia, X.
2017-12-01
In the past two decades, tile drainage installation has accelerated throughout the Red River of the North Basin (RRB) in parts of western Minnesota, eastern North Dakota, and a small area of northeastern South Dakota, because the flat topography and low-permeability soils in this region necessitated the removal of excess water to improve crop production. Interestingly, streamflow in the Red River has markedly increased and six of 13 major floods during the past century have occurred since the late 1990s. It has been suggested that the increase in RRB flooding could be due to change in agricultural practices, including extensive tile drainage installation. Reliable information on existing and future tile drainage installation is greatly needed to capture the rapid extension of tile drainage systems and to locate tile drainage systems in the north central U.S. including the RRB region. However, there are few reliable data of tile drainage installation records, except tile drainage permit records in the Bois de Sioux watershed (a sub-basin in southern part of the RRB where permits are required for tile drainage installation). This study presents a tile drainage expansion detection method based on a physical principle that the soil-drying rate may increase with increasing tile drainage for a given area. In order to capture the rate of change in soil drying rate with time over entire RRB (101,500 km2), two satellite-based microwave soil moisture records from the Advanced Microwave Scanning Radiometer for Earth Observing System (AMSR-E) and AMSR2 were used during 2002 to 2016. In this study, a sub-watershed level (HUC10) potential tile drainage growth map was developed and the results show good agreement with tile drainage permit records of six sub-watersheds in the Bois de Sioux watershed. Future analyses will include improvement of the potential tile drainage map through additional information using optical- and thermal-based sensor products and evaluation of its
-
Dinar, Ariel; Aillery, Marcel P.; Moore, Michael R.
1993-06-01
This paper presents a dynamic model of irrigated agriculture that accounts for drainage generation and salinity accumulation. Critical model relationships involving crop production, soil salinity, and irrigation drainage are based on newly estimated functions derived from lysimeter field tests. The model allocates land and water inputs over time based on an intertemporal profit maximization objective function and soil salinity accumulation process. The model is applied to conditions in the San Joaquin Valley of California, where environmental degradation from irrigation drainage has become a policy issue. Findings indicate that in the absence of regulation, drainage volumes increase over time before reaching a steady state as increased quantities of water are allocated to leaching soil salts. The model is used to evaluate alternative drainage abatement scenarios involving drainage quotas and taxes, water supply quotas and taxes, and irrigation technology subsidies. In our example, direct drainage policies are more cost-effective in reducing drainage than policies operating indirectly through surface water use, although differences in cost efficiency are relatively small. In some cases, efforts to control drainage may result in increased soil salinity accumulation, with implications for long-term cropland productivity. While policy adjustments may alter the direction and duration of convergence to a steady state, findings suggest that a dynamic model specification may not be necessary due to rapid convergence to a comon steady state under selected scenarios.
-
Tang, Xianqiang; Li, Qingyun; Wang, Zhenhua; Hu, Yanping; Hu, Yuan; Scholz, Miklas
2018-03-10
Novel soil remediation equipment based on electro-kinetic geosynthetics (EKG) was developed for in situ isolation of metals from paddy soil. Two mutually independent field plot experiments A and B (with and without electric current applied) were conducted. After saturation using ferric chloride (FeCl 3 ) and calcium chloride (CaCl 2 ), soil water drainage capacity, soil cadmium (Cd) removal performance, energy consumption as well as soil residual of iron (Fe) and chloride (Cl) were assessed. Cadmium dissolved in the soil matrix and resulted in a 100% increase of diethylenetriamine-pentaacetic acid (DTPA) extracted phyto-available Cd. The total soil Cd content reductions were 15.20% and 26.58% for groups A and B, respectively, and electric field applications resulted in a 74.87% increase of soil total Cd removal. The electric energy consumption was only 2.17 kWh/m 3 for group B. Drainage by gravity contributed to > 90% of the overall soil dewatering capacity. Compared to conventional electro-kinetic technology, excellent and fast soil water drainage resulted in negligible hydrogen ion (H + ) and hydroxide ion (OH - ) accumulation at nearby electrode zones, which addressed the challenge of anode corrosion and cathode precipitation of soil metals. External addition of FeCl 3 and CaCl 2 caused soil Fe and Cl residuals and led to 4.33-7.59% and 139-172% acceptable augments in soil total Fe and Cl content, correspondingly, if compared to original untreated soils. Therefore, the novel soil remediation equipment developed based on EKG can be regarded as a promising new in situ technology for thoroughly isolating metals from large-scale paddy soil fields.
-
Reducing nitrate loss in tile drainage water with cover crops and water-table management systems.
Drury, C F; Tan, C S; Welacky, T W; Reynolds, W D; Zhang, T Q; Oloya, T O; McLaughlin, N B; Gaynor, J D
2014-03-01
Nitrate lost from agricultural soils is an economic cost to producers, an environmental concern when it enters rivers and lakes, and a health risk when it enters wells and aquifers used for drinking water. Planting a winter wheat cover crop (CC) and/or use of controlled tile drainage-subirrigation (CDS) may reduce losses of nitrate (NO) relative to no cover crop (NCC) and/or traditional unrestricted tile drainage (UTD). A 6-yr (1999-2005) corn-soybean study was conducted to determine the effectiveness of CC+CDS, CC+UTD, NCC+CDS, and NCC+UTD treatments for reducing NO loss. Flow volume and NO concentration in surface runoff and tile drainage were measured continuously, and CC reduced the 5-yr flow-weighted mean (FWM) NO concentration in tile drainage water by 21 to 38% and cumulative NO loss by 14 to 16% relative to NCC. Controlled tile drainage-subirrigation reduced FWM NO concentration by 15 to 33% and cumulative NO loss by 38 to 39% relative to UTD. When CC and CDS were combined, 5-yr cumulative FWM NO concentrations and loss in tile drainage were decreased by 47% (from 9.45 to 4.99 mg N L and from 102 to 53.6 kg N ha) relative to NCC+UTD. The reductions in runoff and concomitant increases in tile drainage under CC occurred primarily because of increases in near-surface soil hydraulic conductivity. Cover crops increased corn grain yields by 4 to 7% in 2004 increased 3-yr average soybean yields by 8 to 15%, whereas CDS did not affect corn or soybean yields over the 6 yr. The combined use of a cover crop and water-table management system was highly effective for reducing NO loss from cool, humid agricultural soils. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.
-
Modelling soil-water dynamics in the rootzone of structured and water-repellent soils
Brown, Hamish; Carrick, Sam; Müller, Karin; Thomas, Steve; Sharp, Joanna; Cichota, Rogerio; Holzworth, Dean; Clothier, Brent
2018-04-01
In modelling the hydrology of Earth's critical zone, there are two major challenges. The first is to understand and model the processes of infiltration, runoff, redistribution and root-water uptake in structured soils that exhibit preferential flows through macropore networks. The other challenge is to parametrise and model the impact of ephemeral hydrophobicity of water-repellent soils. Here we have developed a soil-water model, which is based on physical principles, yet possesses simple functionality to enable easier parameterisation, so as to predict soil-water dynamics in structured soils displaying time-varying degrees of hydrophobicity. Our model, WEIRDO (Water Evapotranspiration Infiltration Redistribution Drainage runOff), has been developed in the APSIM Next Generation platform (Agricultural Production Systems sIMulation). The model operates on an hourly time-step. The repository for this open-source code is https://github.com/APSIMInitiative/ApsimX. We have carried out sensitivity tests to show how WEIRDO predicts infiltration, drainage, redistribution, transpiration and soil-water evaporation for three distinctly different soil textures displaying differing hydraulic properties. These three soils were drawn from the UNSODA (Unsaturated SOil hydraulic Database) soils database of the United States Department of Agriculture (USDA). We show how preferential flow process and hydrophobicity determine the spatio-temporal pattern of soil-water dynamics. Finally, we have validated WEIRDO by comparing its predictions against three years of soil-water content measurements made under an irrigated alfalfa (Medicago sativa L.) trial. The results provide validation of the model's ability to simulate soil-water dynamics in structured soils.
-
International Nuclear Information System (INIS)
Case, J.B.
2000-01-01
The drainage of water from the emplacement drift is essential for the performance of the EBS. The unsaturated flow properties of the surrounding rock matrix and fractures determine how well the water will be naturally drained. To enhance natural drainage, it may be necessary to introduce engineered drainage features (e.g. drilled holes in the drifts), that will ensure communication of the flow into the fracture system. The purpose of the Water Drainage Model is to quantify and evaluate the capability of the drift to remove water naturally, using the selected conceptual repository design as a basis (CRWMS M andO, 1999d). The analysis will provide input to the Water Distribution and Removal Model of the EBS. The model is intended to be used to provide postclosure analysis of temperatures and drainage from the EBS. It has been determined that drainage from the EBS is a factor important to the postclosure safety case
-
Solar system for soil drainage
International Nuclear Information System (INIS)
Kocic, Z.R.; Stojanovic, J.B.; Antic, M.A.; Pavlovic, T.M.
1999-01-01
The paper reviews solar system for drainage of the cultivable agricultural surfaces which can be situated near the rivers in plains. These are usually very fertile surfaces which cannot be cultivated die to constant presence of the water. Using such solar systems should increase the percentage of cultivable surfaces. These systems can also be installed on the cultivable agricultural surfaces, where the water surfaces or so called still waters appear, which make impossible the application of agritechnical measures on these surfaces, significantly decreasing crops and creating conditions for the growth of pond plants and animals. Increasing the percentage of cultivable agricultural surfaces would increase national agricultural income. At the same time, increasing the percentage of cultivable agricultural surfaces decreases the surfaces of unhealthy bog, swamp and marshland soils, where many insect breed. They are the cause for soil spraying from the air, which causes the pollution of environment. Solar systems do not pollute the environment because they use solar energy as the purest source of energy. Their usage has special significance in the places where there is no electricity distribution network
-
Berton Zanchi, F.; Waterloo, M.J.; Dolman, A.J.; Groenendijk, M.; Kruijt, B.
2011-01-01
Central Amazonian rainforest landscape supports a mosaic of tall terra firme rainforest and ecotone campinarana, riparian and campina forests, reflecting topography-induced variations in soil, nutrient and drainage conditions. Spatial and temporal variations in litter decomposition, soil and
-
WATER RETENTION OPTION OF DRAINAGE SYSTEM FOR DRY SEASON CORN CULTIVATION AT TIDAL LOWLAND AREA
Directory of Open Access Journals (Sweden)
Bakri
2015-10-01
Full Text Available Farming constraint at tidal lowland area is about water management related to the nature of excessive water during wet season and insufficient water during dry season. This field research objectives was to find out the corn crop cultivation in August 2014 which entered dry season. The installation of subsurface drainage that previously had functioned as water discharge was converted into water retention. The research results showed that corn had grown well during peak dry season period (October in which water table was at –50 cm below soil surface, whereas water table depth was dropped to –70 cm below soil surface in land without subsurface drainage. This condition implied that installation of subsurface drainage at dry season had function as water retention, not as water discharge. Therefore, network function was inverted from water discharge into water retention. It had impact on the development of optimum water surface that flow in capillary mode to fulfill the crop’s water requirement. Corn production obtained was 6.4 t ha-1. This condition was very promising though still below the maximum national production. The applications of subsurface drainage was still not optimum due to the supply of water from the main system was not the same because of the soil physical properties diversity and topography differences.
-
Integrated water-crop-soil-management system for evaluating the quality of irrigation water
International Nuclear Information System (INIS)
Pla-Sentis, I.
1983-01-01
The authors make use of an independent balance of the salts and ions present in the water available for irrigation, based on the residence times in the soil solution that are allowed by solubility limits and drainage conditions, to develop an efficient system for evaluating the quality of such water which combines the factors: water, crop, soil and management. The system is based on the principle that such quality depends not only on the concentration and composition of the salts dissolved in the water, but also on existing possibilities and limitations in using and managing it in respect of the soil and crops, with allowance for the crop's tolerance of salinity, drainage conditions and hydrological properties of the soils, climate and current or potential practices for the management of the irrigation. If this system is used to quantify approximately the time behaviour of the concentration and composition of the salts in the soil solution, it is possible not only to predict the effects on soil, crops and drainage water, but also to evaluate the various combinations of irrigation water, soil, crops and management and to select the most suitable. It is also useful for fairly accurately diagnosing current problems of salinity and for identifying alternatives and possibilities for reclamation. Examples of its use for these purposes in Venezuela are presented with particular reference to the diagnosis of the present and future development of ''salino-sodic'' and ''sodic'' soils by means of low-salt irrigation water spread over agricultural soils with very poor drainage in a sub-humid or semi-arid tropical climate. The authors also describe the use of radiation techniques for gaining an understanding of the relations between the factors making up the system and for improving the quantitative evaluations required to diagnose problems and to select the best management methods for the available irrigation water. (author)
-
Microbial community analysis in rice paddy soils irrigated by acid mine drainage contaminated water.
Sun, Min; Xiao, Tangfu; Ning, Zengping; Xiao, Enzong; Sun, Weimin
2015-03-01
Five rice paddy soils located in southwest China were selected for geochemical and microbial community analysis. These rice fields were irrigated with river water which was contaminated by Fe-S-rich acid mine drainage. Microbial communities were characterized by high-throughput sequencing, which showed 39 different phyla/groups in these samples. Among these phyla/groups, Proteobacteria was the most abundant phylum in all samples. Chloroflexi, Acidobacteria, Nitrospirae, and Bacteroidetes exhibited higher relative abundances than other phyla. A number of rare and candidate phyla were also detected. Moreover, canonical correspondence analysis suggested that pH, sulfate, and nitrate were significant factors that shaped the microbial community structure. In addition, a wide diversity of Fe- and S-related bacteria, such as GOUTA19, Shewanella, Geobacter, Desulfobacca, Thiobacillus, Desulfobacterium, and Anaeromyxobacter, might be responsible for biogeochemical Fe and S cycles in the tested rice paddy soils. Among the dominant genera, GOUTA19 and Shewanella were seldom detected in rice paddy soils.
-
Sisson, James B.; van Genuchten, Martinus Th.
1991-04-01
The unsaturated hydraulic properties are important parameters in any quantitative description of water and solute transport in partially saturated soils. Currently, most in situ methods for estimating the unsaturated hydraulic conductivity (K) are based on analyses that require estimates of the soil water flux and the pressure head gradient. These analyses typically involve differencing of field-measured pressure head (h) and volumetric water content (θ) data, a process that can significantly amplify instrumental and measurement errors. More reliable methods result when differencing of field data can be avoided. One such method is based on estimates of the gravity drainage curve K'(θ) = dK/dθ which may be computed from observations of θ and/or h during the drainage phase of infiltration drainage experiments assuming unit gradient hydraulic conditions. The purpose of this study was to compare estimates of the unsaturated soil hydraulic functions on the basis of different combinations of field data θ, h, K, and K'. Five different data sets were used for the analysis: (1) θ-h, (2) K-θ, (3) K'-θ (4) K-θ-h, and (5) K'-θ-h. The analysis was applied to previously published data for the Norfolk, Troup, and Bethany soils. The K-θ-h and K'-θ-h data sets consistently produced nearly identical estimates of the hydraulic functions. The K-θ and K'-θ data also resulted in similar curves, although results in this case were less consistent than those produced by the K-θ-h and K'-θ-h data sets. We conclude from this study that differencing of field data can be avoided and hence that there is no need to calculate soil water fluxes and pressure head gradients from inherently noisy field-measured θ and h data. The gravity drainage analysis also provides results over a much broader range of hydraulic conductivity values than is possible with the more standard instantaneous profile analysis, especially when augmented with independently measured soil water retention data.
-
DEFF Research Database (Denmark)
Vasquez, Vicente; Thomsen, Anton Gårde; Iversen, Bo Vangsø
them have been reported. To compare among methods, one year of four large-scale lysimeters drainage (D) was evaluated against modeled soil deep percolation using either profile soil moisture, bromide breakthrough curves from suction cups, or measured soil hydraulic properties in the laboratory....... Measured volumetric soil water content (q) was 3-4% higher inside lysimeters than in the field probably due to a zero tension lower boundary condition inside lysimeters. D from soil hydraulic properties measured in the laboratory resulted in a 15% higher evapotranspiration and 12% lower drainage...... predictions than the model calibrated with field measured q. Bromide (Br) breakthrough curves indicated high variability between lysimeters and field suction cups with mean Br velocities at first arrival time of 110 and 33 mm/d, respectively. D was 520 mm/yr with lysimeters, 613 mm/yr with the calibrated...
-
Determinants of Nitrous Oxide Emission from Agricultural Drainage Waters
International Nuclear Information System (INIS)
Reay, D. S.; Edwards, A. C.; Smith, K. A.
2004-01-01
Emissions of the powerful greenhouse gas nitrous oxide (N 2 O) from agricultural drainage waters are poorly quantified and its determinants are not fully understood. Nitrous oxide formation in agricultural soils is known to increase in response to N fertiliser application, but the response of N 2 O in field drainage waters is unknown. This investigation combined an intensive study of the direct flux of N 2 O from the surface of a fertilised barley field with measurement of dissolved N 2 O and nitrate (NO 3 ) concentrations in the same field's drainage waters. Dissolved N 2 O in drainage waters showed a clear response to field N fertilisation, following an identical pattern to direct N 2 O flux from the field surface. The range in N 2 O concentrations between individual field drains sampled on the same day was large, indicating considerable spatial variability exists at the farm scale. A consistent pattern of very rapid outgassing of the dissolved N 2 O in open drainage ditches was accentuated at a weir, where increased turbulence led to a clear drop in dissolved N 2 O concentration. This study underlines the need for carefully planned sampling campaigns wherever whole farm or catchment N 2 O emission budgets are attempted. It adds weight to the argument for the downward revision of the IPCC emission factor (EF 5 -g) for NO 3 in drainage waters
-
Determinants of nitrous oxide emission from agricultural drainage waters
International Nuclear Information System (INIS)
Reay, D. S.; Edwards, A. C.; Smith, K. A.
2005-01-01
Emissions of the powerful greenhouse gas nitrous oxide (N 2 O) from agricultural drainage waters are poorly quantified and its determinants are not fully understood. Nitrous oxide formation in agricultural soils is known to increase in response to N fertiliser application, but the response of N 2 O in field drainage waters is unknown. This investigation combined an intensive study of the direct flux of N 2 O from the surface of a fertilised barley field with measurement of dissolved N 2 O and nitrate (NO 3 ) concentrations in the same field's drainage waters. Dissolved N 2 O in drainage waters showed a clear response to field N fertilisation, following an identical pattern to direct N 2 O flux from the field surface. The range in N 2 O concentrations between individual field drains sampled on the same day was large, indicating considerable spatial variability exists at the farm scale. A consistent pattern of very rapid outgassing of the dissolved N 2 O in open drainage ditches was accentuated at a weir, where increased turbulence led to a clear drop in dissolved N 2 O concentration. This study underlines the need for carefully planned sampling campaigns wherever whole farm or catchment N 2 O emission budgets are attempted. It adds weight to the argument for the downward revision of the IPCC emission factor (EF 5 -g) for NO 3 in drainage waters
-
Peeters, L.; Crosbie, R. S.; Doble, R.; van Dijk, A. I. J. M.
2012-04-01
Developing a continental land surface model implies finding a balance between the complexity in representing the system processes and the availability of reliable data to drive, parameterise and calibrate the model. While a high level of process understanding at plot or catchment scales may warrant a complex model, such data is not available at the continental scale. This data sparsity is especially an issue for the Australian Water Resources Assessment system, AWRA-L, a land-surface model designed to estimate the components of the water balance for the Australian continent. This study focuses on the conceptualization and parametrization of the soil drainage process in AWRA-L. Traditionally soil drainage is simulated with Richards' equation, which is highly non-linear. As general analytic solutions are not available, this equation is usually solved numerically. In AWRA-L however, we introduce a simpler function based on simulation experiments that solve Richards' equation. In the simplified function soil drainage rate, the ratio of drainage (D) over storage (S), decreases exponentially with relative water content. This function is controlled by three parameters, the soil water storage at field capacity (SFC), the drainage fraction at field capacity (KFC) and a drainage function exponent (β). [ ] D- -S- S = KF C exp - β (1 - SFC ) To obtain spatially variable estimates of these three parameters, the Atlas of Australian Soils is used, which lists soil hydraulic properties for each soil profile type. For each soil profile type in the Atlas, 10 days of draining an initially fully saturated, freely draining soil is simulated using HYDRUS-1D. With field capacity defined as the volume of water in the soil after 1 day, the remaining parameters can be obtained by fitting the AWRA-L soil drainage function to the HYDRUS-1D results. This model conceptualisation fully exploits the data available in the Atlas of Australian Soils, without the need to solve the non
-
Possibility of soil clean-up from 137Cs in coast part of drainage system
International Nuclear Information System (INIS)
Karlin, Yh.V.; Barinov, A.S.; Prozorov, L.B.; Kropotov, V.N.; Chujkov, V.Yh.; Shcheglov, M.Yh.; Bakanov, A.V.
1996-01-01
The net of drainage canals is used for the collection of the surface ground waters on the radioactive waste storage at the MosNPO RADON. The soils of the drainage system were contaminated by 137-Cs migrating in the direction of the common flow. A unique technology was elaborated permitting to extract 137 Cs from soil 90% and to concentrate 137-Cs on the selective inorganic sorbent (nickel ferrocyanide). This technology combines electrokinetics, membrane and sorption methods of the contaminated media cleaning
-
Water Stress Assessment in Jharkhand State Using Soil Data and GIS
African Journals Online (AJOL)
In this paper an attempt has been made to study the interrelationship of water resources available with that of soil class and its properties including soil drainage and erosional characteristics which has been used to generate drainage stress map and water stress map inferring the basic reason for water scarcity in the district ...
-
The Effect of Different Subsurface Drainage Systems on Improvement of Water Flow in Paddy fields
Directory of Open Access Journals (Sweden)
ghassem aghajani mazandarani
2017-03-01
Full Text Available Introduction: Better use of water and soil resources in paddy fields, increase in rice production and farmer's income, installation of subsurface drainage system is necessary. The main goalof these systems, are aeration conditions improvement prevention of water logging, yield increase, land use increase and multiuse of the land. In different countries, installation of subsurface drainage cause yield increase and working condition on the land, but no research has been conducted in different depths and spacing. On the other hand, spacing and depth are the most important parameters in the installation of drainage systems, have a direct effect on incoming water into the drains. The aim of this research, is an investigation of the effect of subsurface drainage with different depths and spacing on discharge rate variation and water table fall, in order to analyze the improvement of water flow movement in the soil. Also, study the effect of different drainage systems on the increase of the canola yield as the second cultivation in these treatments have been compared. Materials and Methods: To measure hydraulic conductivity in different depths, the auger holes have been dug (excavated. The saturated hydraulic conductivity in these holes wasdetermined using Ernst method (1950 before installation of drainage systems. In the drainage pilot plot of Sari Agricultural Sciences and Natural Resources University three subsurface drainage systems with mineral envelope have been installed. 1- The first one with the 0.9 m depth and 30 m spacing (D90 L30, 2- The second one with 0.65 m depth and 15 m spacing (D0.65 L15 and 3- The third one with 0.65 m depth and spacing (D0.65 L30 and one bi-level system with mineral envelope including four drains of 15 m spacing with 0.9 m and 0.65 m depths were installed alternatively. After auger hole equipment installations, in the middle spacing of two subsurface and water table reading possible, the water table fluctuation and
-
Experimental Investigation of Evaporation and Drainage in Wettable and Water-Repellent Sands
Directory of Open Access Journals (Sweden)
Dae Hyun Kim
2015-05-01
Full Text Available This study presents experimental results on evaporation and drainage in both wettable and water-repellent sands whose surface wettability was artificially modified by silanization. The 2D optical and 3D X-ray computed tomographic imaging was performed during evaporation and the water retention during cyclic drainage and infiltration was measured to assess effects of wettability and initial wetting conditions. The evaporation gradually induces its front at the early stage advance regardless of the wettability and sand types, while its rate becomes higher in water-repellent Ottawa sand than the wettable one. Jumunjin sand which has a smaller particle size and irregular particle shape than Ottawa sand exhibits a similar evaporation rate independent of wettability. Water-repellent sand can facilitate the evaporation when both wettable and water-repellent sands are naturally in contact with each other. The 3D X-ray imaging reveals that the hydraulically connected water films in wettable sands facilitate the propagation of the evaporation front into the soil such that the drying front deeply advances into the soil. For cyclic drainage-infiltration testing, the evolution of water retention is similar in both wettable and water-repellent sands when both are initially wet. However, when conditions are initially dry, water-repellent sands exhibit low residual saturation values. The experimental observations made from this study propose that the surface wettability may not be a sole factor while the degree of water-repellency, type of sands, and initial wetting condition are predominant when assessing evaporation and drainage behaviors.
-
Directory of Open Access Journals (Sweden)
Ireneusz Cymes
2014-10-01
Full Text Available The study included groundwater outflow drainage systems and collected in the pond located at the agricultural use area in the portion of the drainage facility Lidzbark Warminski located on the Sępopolska Plain. The study was performed in two periods: the first one was in 1998–2000 (just after was made drainage, in which the discussed area was used as pasture, and the second in 2008–2010, in which after plowed of the soil was cultivated winter wheat. The aim of the study was to determine changes in water quality after the change of the way of land use. Examinations showed that as a result of the change of the way of using the area and ceasing of mineral fertilizing in waters of the pond was a reduction in the concentrations of the most mineral components, but an increase of pH reaction and concentrations of potassium, magnesium of sulfates and bicarbonates. In groundwaters observed increased the content of concentrations of mineral forms of nitrogen, phosphatic phosphorus, potassium, magnesium, general iron and bicarbonates, and a reduction in the concentrations of calcium, sodium, sulfates and chlorides. However in the water which outflow from drainage pipelines system from the research area was an increase of concentrations most of the determined substances, apart from ammonia nitrogen and chlorides.
-
Directory of Open Access Journals (Sweden)
Mohamed Abou Niang
2012-01-01
Full Text Available Discriminant analysis classification (DAC and decision tree classifiers (DTC were used for digital mapping of soil drainage in the Bras-d’Henri watershed (QC, Canada using earth observation data (RADARSAT-1 and ASTER and soil survey dataset. Firstly, a forward stepwise selection was applied to each land use type identified by ASTER image in order to derive an optimal subset of soil drainage class predictors. The classification models were then applied to these subsets for each land use and merged to obtain a digital soil drainage map for the whole watershed. The DTC method provided better classification accuracies (29 to 92% than the DAC method (33 to 79% according to the land use type. A similarity measure (S was used to compare the best digital soil drainage map (DTC to the conventional soil drainage map. Medium to high similarities (0.6≤S<0.9 were observed for 83% (187 km2 of the study area while 3% of the study area showed very good agreement (S≥0.9. Few soil polygons showed very weak similarities (S<0.3. This study demonstrates the efficiency of combining radar and optical remote sensing data with a representative soil dataset for producing digital maps of soil drainage.
-
Automated Passive Capillary Lysimeters for Estimating Water Drainage in the Vadose Zone
Jabro, J.; Evans, R.
2009-04-01
In this study, we demonstrated and evaluated the performance and accuracy of an automated PCAP lysimeters that we designed for in-situ continuous measuring and estimating of drainage water below the rootzone of a sugarbeet-potato-barley rotation under two irrigation frequencies. Twelve automated PCAPs with sampling surface dimensions of 31 cm width * 91 cm long and 87 cm in height were placed 90 cm below the soil surface in a Lihen sandy loam. Our state-of-the-art design incorporated Bluetooth wireless technology to enable an automated datalogger to transmit drainage water data simultaneously every 15 minutes to a remote host and had a greater efficiency than other types of lysimeters. It also offered a significantly larger coverage area (2700 cm2) than similarly designed vadose zone lysimeters. The cumulative manually extracted drainage water was compared with the cumulative volume of drainage water recorded by the datalogger from the tipping bucket using several statistical methods. Our results indicated that our automated PCAPs are accurate and provided convenient means for estimating water drainage in the vadose zone without the need for costly and manually time-consuming supportive systems.
-
In-situ measurements of soil-water conductivity
International Nuclear Information System (INIS)
Murphy, C.E.
1978-01-01
Radionuclides and other environmentally important materials often move in association with water. In terrestrial ecosystems, the storage and movement of water in the soil is of prime importance to the hydrologic cycle of the ecosystem. The soil-water conductivity (the rate at which water moves through the soil) is a necessary input to models of soil-water movement. In situ techniques for measurement of soil-water conductivity have the advantage of averaging soil-water properties over larger areas than most laboratory methods. The in situ techniques also cause minimum disturbance of the soil under investigation. Results of measurements using a period of soil-water drainage after initial wetting indicate that soil-water conductivity and its variation with soil-water content can be determined with reasonable accuracy for the plot where the measurements were made. Further investigations are being carried out to look at variability between plots within a soil type
-
Migratory bird habitat in relation to tile drainage and poorly drained hydrologic soil groups
Kastner, Brandi; Christensen, Victoria G.; Williamson, Tanja N.; Sanocki, Chris A.
2016-01-01
The Prairie Pothole Region (PPR) is home to more than 50% of the migratory waterfowl in North America. Although the PPR provides an abundance of temporary and permanent wetlands for nesting and feeding, increases in commodity prices and agricultural drainage practices have led to a trend of wetland drainage. The Northern Shoveler is a migratory dabbling duck species that uses wetland habitats and cultivated croplands in the PPR. Richland County in North Dakota and Roberts County in South Dakota have an abundance of wetlands and croplands and were chosen as the study areas for this research to assess the wetland size and cultivated cropland in relation to hydrologic soil groups for the Northern Shoveler habitat. This study used geographic information system data to analyze Northern Shoveler habitats in association with Natural Resource Conservation Service soil data. Habitats, which are spatially associated with certain hydrologic soil groups, may be at risk of artificial drainage installations because of their proximity to cultivated croplands and soil lacking in natural drainage that may become wet or inundated. Findings indicate that most wetlands that are part of Northern Shoveler habitats were within or adjacent to cultivated croplands. The results also revealed soil hydrologic groups with high runoff potential and low water transmission rates account for most of the soil within the Northern Shoveler‘s wetland and cropland habitats. Habitats near agriculture with high runoff potential are likely to be drained and this has the potential of reducing Northern Shoveler habitat.
-
Directory of Open Access Journals (Sweden)
V. Moca
2009-10-01
Full Text Available The soil-climatic conditions from Baia Depression – the hydrographical basin from the extra-Carpathian area of the Moldova River - have frequently determined the presence, under different forms, intensities and periods, of temporary water excess from soil. The underground drainage, as a measure of water excess control, with stagnant character, caused mainly by rainfall amounts registered for 1-5 consecutive days, was firstly arranged in pilot-experimental fields during 1972-1978. We followed the behaviour in exploitation of underground drainage technical solutions, as concerns the functional efficiency of the means of water excess removal and of the improved soil favourableness and/or suitability for crop growing.In order to assess the long-term effects of ameliorating works, applied in 1978 in the drainage field of Baia, on an area of 3.50 ha, we have qualitatively classified and estimated the albic stagnic glossic Luvosoil (S.R.T.S. – 2003, improved and unimproved. Based on this study, we have estimated the present favourableness for crops of the improved soil, as compared to unimproved soil, used as natural grassland, after an exploitation cycle of 30 years (1978- 2008.
-
Passive capillary samplers (PCAPs) are widely used to monitor, measure and sample drainage water under saturated and unsaturated soil conditions in the vadose zone. The objective of this study was to evaluate the performance and accuracy of automated passive capillary sampler for estimating drainage...
-
Directory of Open Access Journals (Sweden)
I. BÄRLUND
2008-12-01
Full Text Available To abate the environmental problems caused by the severe acidity and high metal concentrations in rivers draining acid sulphate (AS soils of Western Finland, control drainage (CD and lime filter drainage (LFD, and their combination, were investigated. The effectiveness of these best management practices (BMPs on drainage water quality was studied on plot scale in two locations. In Ilmajoki, where the sulphidic materials are more than 2 m below the soil surface, CD efficiently reduced the concentrations of sulphate, aluminium, manganese and iron concentrations and to some extent also increased the pH of the drainage waters. LFD, in contrast, effectively reduced the drainage water acidity and raised the pH level. Decrease of the groundwater level owing to strong evapotranspiration in summer could, however, not be properly prevented by CD. In Mustasaari where sulphidic materials were as shallow as 1 m below soil surface, the positive effects of LFD recognised in Ilmajoki were hardly seen. This shows, that the tested BMPs work properly, and can thus be recommended, for intensively artificially drained AS soils like in Ilmajoki where most of the acidity has already been transported to watercourses. LFD can, however, not be recommended for as yet poorly leached and thus particularly problematic AS soils like in Mustasaari. This is, of course, a drawback of the tested BMP, as it is not effective for the soils which would need it most. The field data were tentatively utilised to test the performance of the HAPSU (Ionic Flow Model for Acid Sulphate Soils simulation model developed to estimate the loads of harmful substances from AS soils.;
-
International Nuclear Information System (INIS)
Karlin, Y.V.; Chuikov, V.Y.; Belianina, N.G.; Barinov, A.S.
1996-01-01
In this paper is considered the possibility of the cleaning from the radionuclides for the coast parts of the drainage system at the Moscow SIA open-quotes Radonclose quotes by the soil fractionating treatment. It is showed that this method cannot to be used for the cleaning of the soils near water flowing (a river, a spring or a open drainage system) because the most part of the soil size-fractions is the fine fractions and the main contaminant radionuclide ( 137 Cs) is distributed among the different soil components homogeneously
-
Definition of the drainage filter problem
Zaslavsky, D.
1977-01-01
It is common to consider the following: I. Retention of soil particles that may enter the drainage pipe and cause its clogging. For some sensitive structures it is important to prevent settlements due to soil transportation by drainage water.
-
Staring Centrum, Instituut voor Onderzoek van het LandelijkGebied
1995-01-01
The effects of reusing drainage water have been evaluated and other options to increase the water utilization rate in Egypt explored. The results are an operational network for monitoring drainage water discharges and salinity along the major drains, a database for monitored drainage water
-
Water quality issues associated with agricultural drainage in semiarid regions
Sylvester, Marc A.
High incidences of mortality, birth defects, and reproductive failure in waterfowl using Kesterson Reservoir in the San Joaquin Valley, Calif., have occurred because of the bioaccumulation of selenium from irrigation drainage. These circumstances have prompted concern about the quality of agriculture drainage and its potential effects on human health, fish and wildlife, and beneficial uses of water. The U.S. Geological Survey (USGS) and Lawrence Berkeley Laboratory, University of California (Berkeley, Calif.) organized a 1-day session at the 1986 AGU Fall Meeting in San Francisco, Calif., to provide an interdisciplinary forum for hydrologists, geochemists, and aquatic chemists to discuss the processes controlling the distribution, mobilization, transport, and fate of trace elements in source rocks, soils, water, and biota in semiarid regions in which irrigated agriculture occurs. The focus of t h e session was the presentation of research results on the source, distribution, movement, and fate of selenium in agricultural drainage.
-
Angstmann, J L; Ewers, B E; Kwon, H
2012-05-01
Boreal forests are crucial to climate change predictions because of their large land area and ability to sequester and store carbon, which is controlled by water availability. Heterogeneity of these forests is predicted to increase with climate change through more frequent wildfires, warmer, longer growing seasons and potential drainage of forested wetlands. This study aims at quantifying controls over tree transpiration with drainage condition, stand age and species in a central Canadian black spruce boreal forest. Heat dissipation sensors were installed in 2007 and data were collected through 2008 on 118 trees (69 Picea mariana (Mill.) Britton, Sterns & Poggenb. (black spruce), 25 Populus tremuloides Michx. (trembling aspen), 19 Pinus banksiana Lamb. (jack pine), 3 Larix laricina (Du Roi) K. Koch (tamarack) and 2 Salix spp. (willow)) at four stand ages (18, 43, 77 and 157 years old) each containing a well- and poorly-drained stand. Transpiration estimates from sap flux were expressed per unit xylem area, J(S), per unit ground area, E(C) and per unit leaf area, E(L), using sapwood (A(S)) and leaf (A(L)) area calculated from stand- and species-specific allometry. Soil drainage differences in transpiration were variable; only the 43- and 157-year-old poorly-drained stands had ∼ 50% higher total stand E(C) than well-drained locations. Total stand E(C) tended to decrease with stand age after an initial increase between the 18- and 43-year-old stands. Soil drainage differences in transpiration were controlled primarily by short-term physiological drivers such as vapor pressure deficit and soil moisture whereas stand age differences were controlled by successional species shifts and changes in tree size (i.e., A(S)). Future predictions of boreal climate change must include stand age, species and soil drainage heterogeneity to avoid biased estimates of forest water loss and latent energy exchanges.
-
Soil bioengineering methods for abandoned mine land surface drainage channels
Energy Technology Data Exchange (ETDEWEB)
Sotir, R.B.; Simms, A.P.; Sweigard, R.J.; Hammer, P.; Graves, D.H.; Adkins, M. [Robbin B. Sotir & Associates, Marietta, GA (USA)
1999-07-01
Research to determine the suitability of soil bioengineering for slope stabilization at abandoned surface mining sites is described. The technology uses live woody plant material as a structural component, in this case live fascine with coir erosion control fabric made from coconut. A large water collection pond draining to nine channels on the slope below was constructed as a test site. The pond has drainage channels for testing at low, intermediate, and steep slope grades. Each group of three channels is composed of one riprap rock channel, one gabion channel, and one soil bioengineering channel. The channels will be tested summer 1999. 11 refs., 5 figs., 2 tabs., 8 photos.
-
Soil water status under perennial and annual pastures on an acid duplex soil
International Nuclear Information System (INIS)
Heng, L.K.; White, R.E.; Chen, D.
2000-01-01
A comprehensive field study of soil water balance, nitrogen (N) cycling, pasture management and animal production was carried out on an acid duplex soil at Book Book near Wagga Wagga in southern New South Wales. The experiment, carried out over a 3-year period, tested the hypothesis that sown perennial grass pastures improve the sustainability of a grazing system through better use of water and N. The treatments were: annual pastures without lime (AP-), annual pastures with lime (AP+), perennial pastures without lime (PP-) and perennial pastures with lime (PP+). Soil water measurement was made using a neutron probe on one set of the treatments comprising four adjacent paddocks. Over three winter and spring periods, the results showed that perennial grass pastures, especially PP+, consistently extracted about 40 mm more soil water each year than did the annual grass pastures. As a result, surface runoff, sub-surface flow and deep drainage (percolation below 180 cm depth) were about 40 mm less from the perennial pastures. The soil water status of the four pasture treatments was simulated reasonably well using a simple soil water model. Together with the long-term simulation of deep drainage, using past meteorological records, it is shown that proper management of perennial pastures can reduce recharge to groundwater and make pastoral systems more sustainable in the high rainfall zone. However, to completely reduce recharge, more-deeply rooted plants or trees are needed. (author)
-
Evaluation of soil and water salinity for irrigation in North-eastern ...
African Journals Online (AJOL)
For sound land use and water management in irrigated area, knowledge of the chemical composition of soils, water, climate, drainage condition and irrigation methods before action are crucial for sustainability of irrigation projects. The study aimed to evaluate the physicochemical properties of soils and water for intended ...
-
Effect of subsurface drainage on salt movement and distribution in salt-affected soils
International Nuclear Information System (INIS)
Moustafa, A.T.A.; Seliem, M.H.; Bakhati, H.K.
1983-01-01
This study was carried out to evaluate different subsurface drainage treatments (combinations of depth and spacing) on salt movement and distribution. The soil is clay and the drainage was designed according to the steady-state condition (Hooghoudt's equation). Three spacings and two depths resulted in six drainage treatments. Soil samples represented the initial state of every treatment and after 14 months they (cotton followed by wheat) were analysed. The data show that drain depth has its effective role in salt leaching, while drain spacing has its effect on salt distribution in the soil profile. The leaching rate of each specific ion is also affected by the different drainage treatments. In general, the salt movement and distribution should be taken into consideration when evaluating the design of drainage systems. (author)
-
Angstmann, J. L.; Ewers, B. E.; Kwon, H.; Bond-Lamberty, B.; Amiro, B.; Gower, S. T.
2008-12-01
Boreal forests are an integral component in obtaining a predictive understanding of global climate change because they comprise 33% of the world's forests and store large amounts of carbon. Much of this carbon storage is a result of peat formation in cold, poorly-drained soils. Transpiration plays a crucial role in the interaction between carbon and water cycles due to stomatal control of these fluxes. The primary focus of this study is to quantify the spatial variability and drivers of tree transpiration in boreal forest stands across a well- to poorly-drained soil drainage gradient. Species composition of this region of boreal forest changes during succession in well-drained soils from being primarily dominated by Picea mariana with co-dominant Pinus banksiana and Populus tremuloides in younger stands to being dominated solely by Picea marianain older stands. Poorly-drained soils are dominated by Picea mariana and change little with succession. Previous work in well-drained stands showed that 1) tree transpiration changed substantially with stand age due to sapwood-to-leaf area ratio dynamics and 2) minimum leaf water potential (Ψ) was kept constant to prevent excessive cavitation. We hypothesized that 1) minimum Ψ would be constant, 2) transpiration would be proportional to the sapwood-to-leaf area ratio across a soil drainage gradient, and 3) spatial relationships between trees would vary depending on stomatal responses to vapor pressure deficit (D). We tested these hypotheses by measuring Ψ of 33 trees and sap flux from 204 trees utilizing cyclic sampling constructed to study spatial relationships. Measurements were conducted at a 42-year-old stand representing maximum tree diversity during succession. There were no significant differences between growing season averaged Ψ in well- (-0.35 and -1.37 for pre-dawn and mid-day respectively) and poorly- drained soil conditions (-0.38 and -1.41 for pre-dawn and mid-day respectively) for Picea mariana. Water use
-
An efficient soil water balance model based on hybrid numerical and statistical methods
Mao, Wei; Yang, Jinzhong; Zhu, Yan; Ye, Ming; Liu, Zhao; Wu, Jingwei
2018-04-01
Most soil water balance models only consider downward soil water movement driven by gravitational potential, and thus cannot simulate upward soil water movement driven by evapotranspiration especially in agricultural areas. In addition, the models cannot be used for simulating soil water movement in heterogeneous soils, and usually require many empirical parameters. To resolve these problems, this study derives a new one-dimensional water balance model for simulating both downward and upward soil water movement in heterogeneous unsaturated zones. The new model is based on a hybrid of numerical and statistical methods, and only requires four physical parameters. The model uses three governing equations to consider three terms that impact soil water movement, including the advective term driven by gravitational potential, the source/sink term driven by external forces (e.g., evapotranspiration), and the diffusive term driven by matric potential. The three governing equations are solved separately by using the hybrid numerical and statistical methods (e.g., linear regression method) that consider soil heterogeneity. The four soil hydraulic parameters required by the new models are as follows: saturated hydraulic conductivity, saturated water content, field capacity, and residual water content. The strength and weakness of the new model are evaluated by using two published studies, three hypothetical examples and a real-world application. The evaluation is performed by comparing the simulation results of the new model with corresponding results presented in the published studies, obtained using HYDRUS-1D and observation data. The evaluation indicates that the new model is accurate and efficient for simulating upward soil water flow in heterogeneous soils with complex boundary conditions. The new model is used for evaluating different drainage functions, and the square drainage function and the power drainage function are recommended. Computational efficiency of the new
-
Directory of Open Access Journals (Sweden)
V. Moca
2007-10-01
Full Text Available In the pedo-climatic conditions of Suceava County that extends on a total surface of 855 300 ha, the balance of agricultural land affected by humidity excess with temporar or permanent character is differenciated from south to north and from east to west, between 30 % till 40%, which means almost 100 000 ha. On these soils with underground water or pluvial excess hydro ameliorative drainage systems have been installed, associated to a complex agroameliorative works. For long effect estimation of the underground drainage asociated with the agropedoameliorative works upon the some chemical properties, there were analyzed the soil and the environment conditions from Baia field.
-
Natural attenuation of antimony in mine drainage water
International Nuclear Information System (INIS)
Manaka, Mitsuo; Yanase, Nobuyuki; Sato, Tsutomu; Fukushi, Keisuke
2007-01-01
In this study, we investigated the natural attenuation of antimony (Sb) in the drainage water of an abandoned mine. Drainage water, waste rocks, and ocherous precipitates collected from the mine were investigated in terms of their mineralogy and chemistry. The chemistry of the drainage water was analyzed by measuring pH, oxidation-reduction potential (ORP), and electric conductivity on site as well as by inductively coupled plasma mass spectrometry and ion chromatography. As the drainage flowed downstream, the pH decreased rapidly from 7.05 to 3.26 and then increased slowly to 3.50. In a section where the pH increased, ocherous precipitates occur on a drainage water channel. We determined Sb levels in the drainage water, and the distribution of Sb in the mineral phases of waste rocks and precipitates was estimated by means of a sequential extraction procedure. The results of these investigations indicated that Sb, which is generated by the dissolution of stibnite (Sb 2 S 3 ) and secondary formed Sb minerals in waste rocks, was attenuated by iron-bearing ocherous precipitates, especially schwertmannite, that form over time in the drainage water. The Sb concentrations in the ocherous precipitates were up to 370 mg/kg, whereas the Sb concentrations in the drainage water downstream were below background levels (0.6 μg/L). Bulk distribution coefficients (K d ) for this Sb adsorption to the precipitates ranges up to at least 10 5 L/kg. (author)
-
Grimley, D.A.; Wang, J.-S.; Liebert, D.A.; Dawson, J.O.
2008-01-01
Flooded, saturated, or poorly drained soils are commonly anaerobic, leading to microbially induced magnetite/maghemite dissolution and decreased soil magnetic susceptibility (MS). Thus, MS is considerably higher in well-drained soils (MS typically 40-80 ?? 10-5 standard international [SI]) compared to poorly drained soils (MS typically 10-25 ?? 10-5 SI) in Illinois, other soil-forming factors being equal. Following calibration to standard soil probings, MS values can be used to rapidly and precisely delineate hydric from nonhydric soils in areas with relatively uniform parent material. Furthermore, soil MS has a moderate to strong association with individual tree species' distribution across soil moisture regimes, correlating inversely with independently reported rankings of a tree species' flood tolerance. Soil MS mapping can thus provide a simple, rapid, and quantitative means for precisely guiding reforestation with respect to plant species' adaptations to soil drainage classes. For instance, in native woodlands of east-central Illinois, Quercus alba , Prunus serotina, and Liriodendron tulipifera predominantly occur in moderately well-drained soils (MS 40-60 ?? 10-5 SI), whereas Acer saccharinum, Carya laciniosa, and Fraxinus pennsylvanica predominantly occur in poorly drained soils (MS Urbana, IL, U.S.A.). Through use of soil MS maps calibrated to soil drainage class and native vegetation occurrence, restoration efforts can be conducted more successfully and species distributions more accurately reconstructed at the microecosystem level. ?? 2008 Society for Ecological Restoration International.
-
Institute of Scientific and Technical Information of China (English)
DONG Bin; MAO Zhi; BROWN Larry; CHEN XiuHong; PENG LiYuan; WANG JianZhang
2009-01-01
Excessive application of fertilizers and pesticides as well as discharge of undecontaminated and un-recycled waste of livestock and poultry into farmland has caused serious non-point source pollution (NSP) of farmland in China.With the traditional mode of irrigation and drainage in rice-based irrigation systems, the pollution of farmland drainage water has become more and more serious.Traditional ir-rigation and drainage systems only focus on issues concerning water quantity, i.e.the capacity of irri-gation in drought and drainage in waterlogging period, yet have no requirement on water quality im-provement, how to clean the water quality of farmland drainage through remodeling the existing irriga-tion and drainage systems has a very important realistic meaning.Pond is an important irrigation facil-ity in rice-based irrigation systems in southern China, which has the functions of not only a storage of water from canals but also collections of surface runoffs and farmland drainage for recycling use.Such water storage features of pond provide the possibility and potential capacity for drainage water treat-ment by managing such features as treatment basins as the growth of aquatic plants as well as living of fishes, batrachia and microorganisms in pond forms a soil-plant-microorganism ecological system.To explore the potential capacity of pond for drainage water nutrient reduction, the Zhanghe Irrigation System of Hubei, a typical "melon-on-the-vine" system in southern China is selected as the research site.The results of pond survey and field experiments demonstrate that plenty of ponds are suitable for collecting and cleaning paddy field drainage, and the ponds are favorable in reducing N, P nutrients in the drainage water.Other issues, e.g.how to maximize such capacity and what strategies should be sought to make existing treatment basins hydraulically more efficient, are also discussed.
-
Institute of Scientific and Technical Information of China (English)
BROWN; Larry
2009-01-01
Excessive application of fertilizers and pesticides as well as discharge of undecontaminated and unrecycled waste of livestock and poultry into farmland has caused serious non-point source pollution (NSP) of farmland in China. With the traditional mode of irrigation and drainage in rice-based irrigation systems, the pollution of farmland drainage water has become more and more serious. Traditional irrigation and drainage systems only focus on issues concerning water quantity, i.e. the capacity of irrigation in drought and drainage in waterlogging period, yet have no requirement on water quality improvement. how to clean the water quality of farmland drainage through remodeling the existing irrigation and drainage systems has a very important realistic meaning. Pond is an important irrigation facility in rice-based irrigation systems in southern China, which has the functions of not only a storage of water from canals but also collections of surface runoffs and farmland drainage for recycling use. Such water storage features of pond provide the possibility and potential capacity for drainage water treatment by managing such features as treatment basins as the growth of aquatic plants as well as living of fishes, batrachia and microorganisms in pond forms a soil-plant-microorganism ecological system. To explore the potential capacity of pond for drainage water nutrient reduction, the Zhanghe Irrigation System of Hubei, a typical "melon-on-the-vine" system in southern China is selected as the research site. The results of pond survey and field experiments demonstrate that plenty of ponds are suitable for collecting and cleaning paddy field drainage, and the ponds are favorable in reducing N, P nutrients in the drainage water. Other issues, e.g. how to maximize such capacity and what strategies should be sought to make existing treatment basins hydraulically more efficient, are also discussed.
-
Vertical distribution of phosphorus in agricultural drainage ditch soils.
Vaughan, Robert E; Needelman, Brian A; Kleinman, Peter J A; Allen, Arthur L
2007-01-01
Pedological processes such as gleization and organic matter accumulation may affect the vertical distribution of P within agricultural drainage ditch soils. The objective of this study was to assess the vertical distribution of P as a function of horizonation in ditch soils at the University of Maryland Eastern Shore Research Farm in Princess Anne, Maryland. Twenty-one profiles were sampled from 10 agricultural ditches ranging in length from 225 to 550 m. Horizon samples were analyzed for total P; water-extractable P; Mehlich-3 P; acid ammonium oxalate-extractable P, Fe, and Al (P ox, Fe ox, Al ox); pH; and organic C (n = 126). Total P ranged from 27 to 4882 mg kg(-1), P ox from 4 to 4631 mg kg(-1), Mehlich-3 P from 2 to 401 mg kg(-1), and water-extractable P from 0 to 17 mg kg(-1). Soil-forming processes that result in differences between horizons had a strong relationship with various P fractions and P sorption capacity. Fibric organic horizons at the ditch soil surface had the greatest mean P ox, Fe ox, and Al ox concentrations of any horizon class. Gleyed A horizons had a mean Fe ox concentrations 2.6 times lower than dark A horizons and were significantly lower in total P and P ox. Variation in P due to organic matter accumulation and gleization provide critical insight into short- and long-term dynamics of P in ditch soils and should be accounted for when applying ditch management practices.
-
Experimental analysis of drainage and water storage of litter layers
Guevara-Escobar, A.; Gonzalez-Sosa, E.; Ramos-Salinas, M.; Hernandez-Delgado, G. D.
2007-06-01
Leaf litter overlying forested floors are important for erosion control and slope stability, but also reduces pasture growth in silvopastoral systems. Little information exists regarding the value of percolation and storage capacity parameters for litter layers. These estimates are needed for modelling better management practices for leaf litter. Therefore, this work measured the effect of four rainfall intensities: 9.8, 30.2, 40.4 and 70.9 mm h-1 on the hydrological response of layers of three materials: recently senesced poplar leaves, fresh grass and woodchips. Maximum storage (Cmax), defined as the detention of water immediately before rainfall cessation, increased with rainfall intensity. The magnitude of the increment was 0.2 mm between the lowest and highest rainfall intensities. Mean values of Cmax were: 1.27, 1.51, 1.67 and 1.65 mm for poplar leaves; 0.63 0.77, 0.73 and 0.76 for fresh grass and; 1.64, 2.23, 2.21 and 2.16 for woodchips. Drainage parameters were: 9.9, 8.8 and 2.2 mm-1 for poplar, grass and woodchips layers. An underlying soil matrix influenced the drainage flow from poplar leaf layers producing pseudo-Hortonian overland flow, but this occurred only when the rainfall intensity was 40.4 and 70.9 mm h-1 and accounted for 0.4 and 0.8‰ of total drainage. On the other hand, the presence of a poplar leaf layer had a damping effect on the drainage rate from the underlying soil matrix, particularly at intermediate rainfall intensities: 30.2 or 40.4 mm h-1.
-
Solid Cattle Manure Less Prone to Phosphorus Loss in Tile Drainage Water.
Wang, Y T; Zhang, T Q; Tan, C S; Qi, Z M; Welacky, T
2018-03-01
Forms (e.g., liquid and solid) of manure influence the risk of P loss after land application. The objective of this study was to investigate the effects of P-based application of various forms of cattle manure (liquid, LCM; or solid, SCM) or inorganic P as triple superphosphate (IP) on soil P losses in tile drainage water. A 4-yr field experiment was conducted in a clay loam soil with a corn ( L.)-soybean [ (L.) Merr.] rotation in the Lake Erie basin. Over the 4 yr, the dissolved reactive P (DRP) flow-weighted mean concentration (FWMC) in tile drainage water was greater under SCM fertilization than under either IP or LCM fertilization. Despite its lower value on an annual basis, DRP FWMC rose dramatically immediately after LCM application. However, the differences in DRP FWMC did not result in detectable differences in DRP loads. Regarding particulate P and total P losses during the 4 yr, they were 68 and 47%, respectively, lower in the soils amended with SCM than in those with IP, whereas both values were similar between IP and LCM treatments. Overall, the P contained in solid cattle manure was less prone to P loss after land application. Accordingly, the present results can provide a basis for manure storage and application of best management practices designed to reduce P losses and improve crop growth. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.
-
Application of BIM Technology in Building Water Supply and Drainage Design
Wei, Tianyun; Chen, Guiqing; Wang, Junde
2017-12-01
Through the application of BIM technology, the idea of building water supply and drainage designers can be related to the model, the various influencing factors to affect water supply and drainage design can be considered more comprehensively. BIM(Building information model) technology assist in improving the design process of building water supply and drainage, promoting the building water supply and drainage planning, enriching the building water supply and drainage design method, improving the water supply and drainage system design level and building quality. Combined with fuzzy comprehensive evaluation method to analyze the advantages of BIM technology in building water supply and drainage design. Therefore, application prospects of BIM technology are very worthy of promotion.
-
Soil and water nitrate levels in relation to fertilizer utilization in Yugoslavia
International Nuclear Information System (INIS)
Filipovic, R.; Stevanovic, D.
1980-01-01
The results of a number of field experiments and monitoring of drainage canals close to intensive agricultural production involving the application of mineral fertilizers are reported. The object was to determine whether the pollution potential of underground and derived surface waters by nitrates and phosphates could be expressed as a function of the applied doses of fertilizer, method of application, climate, soil, etc. Analytical data indicated that, in surface waters adjacent to fertilized land, nitrate levels were higher than those of surface waters adjacent to unfertilized land. Preliminary results on the distribution of NO 3 down the soil profile following the application of 15 N-labelled ammonium nitrate to maize indicated downward movement of the labelled nitrate below the 100-cm depth. Application of organic matter with the fertilizer apparently retarded the leaching process. Soil-surface drainage water was characterized by high P/N ratios. (author)
-
Changes of the water isotopic composition in unsaturated soils
International Nuclear Information System (INIS)
Feurdean, Victor; Feurdean, Lucia
2001-01-01
Based on the spatial and temporal variations of the stable isotope content in precipitation - as input in subsurface - and the mixing processes, the deuterium content in the water that moves in unsaturated zones was used to determine the most conducive season to recharge, the mechanisms for infiltration of snow or rain precipitation in humid, semi-arid or arid conditions, the episodic cycles of infiltration water mixing with the already present soil water and water vapor and whether infiltration water is or is not from local precipitation. Oscillations in the isotopic profiles of soil moisture can be used to estimate the following aspects: where piston or diffusive flow is the dominant mechanisms of water infiltration; the average velocities of the water movement in vadose zone; the influence of vegetation cover, soil type and slope exposure on the dynamics of water movement in soil; the conditions required for infiltration such as: the matrix, gravity, pressure and osmotic potentials during drainage in unsaturated soil. (authors)
-
Subsurface drainage volume reduction with drainage water management: Case studies in Ohio, USA
One of the main contributors to poor water quality in the Mississippi River and aeral increase in the hypoxic zone in the Gulf of Mexico is intensive drainage of the cropland within the watershed. Controlled drainage has been demonstrated as an approach to curb totla drainage outflow and nutrient di...
-
Effect of Drainage Conditions on Cone Penetration Testing in Silty Soils
DEFF Research Database (Denmark)
Poulsen, Rikke; Nielsen, Benjaminn Nordahl; Ibsen, Lars Bo
2011-01-01
This paper discusses the challenges that occur when performing Cone Penetration Tests (CPT) in silty soil due to changes in drainage conditions. In this paper, CPT results from various papers and researchers are collected and interpreted. Results from cone penetrations tests with various penetrat......This paper discusses the challenges that occur when performing Cone Penetration Tests (CPT) in silty soil due to changes in drainage conditions. In this paper, CPT results from various papers and researchers are collected and interpreted. Results from cone penetrations tests with various...
-
International Nuclear Information System (INIS)
Schneider, S.; Jacques, D.; Mallants, D.
2010-01-01
For modelling complex hydrological problems, realistic models and accurate hydraulic properties are needed. A mechanistic model (HYDRUS-1D) and a compartment model are evaluated for simulating the water balance in a soil-vegetation-atmosphere system using time series of measured water content at several depths in two lysimeters in a podzol soil with Scots Pine vegetation. 10 calibration scenarios are used to investigate the impact of the model type and the number of horizons in the profile on the calibration accuracy. Main results are: (i) with a large number of soil layers, both models describe accurately the water contents at all depths, (II) the number of soil layers is the major factor that controls the quality of the calibration. The compartment model is as an abstracted model and the mechanistic model is our reference model. Drainage values are the considered output. Drainage values simulated by the abstracted model were close to those of the reference model when averaged over a sufficiently long period (about 9 months). This result suggests that drainage values obtained with an abstracted model are reliably when averaged over sufficiently long periods; the abstracted model needs less computational time without an important loss of accuracy.
-
Energy Technology Data Exchange (ETDEWEB)
Schneider, S.; Jacques, D.; Mallants, D.
2010-02-15
For modelling complex hydrological problems, realistic models and accurate hydraulic properties are needed. A mechanistic model (HYDRUS-1D) and a compartment model are evaluated for simulating the water balance in a soil-vegetation-atmosphere system using time series of measured water content at several depths in two lysimeters in a podzol soil with Scots Pine vegetation. 10 calibration scenarios are used to investigate the impact of the model type and the number of horizons in the profile on the calibration accuracy. Main results are: (i) with a large number of soil layers, both models describe accurately the water contents at all depths, (II) the number of soil layers is the major factor that controls the quality of the calibration. The compartment model is as an abstracted model and the mechanistic model is our reference model. Drainage values are the considered output. Drainage values simulated by the abstracted model were close to those of the reference model when averaged over a sufficiently long period (about 9 months). This result suggests that drainage values obtained with an abstracted model are reliably when averaged over sufficiently long periods; the abstracted model needs less computational time without an important loss of accuracy.
-
Successful monitoring of pollutant transport through the soil profile requires accurate, reliable, and appropriate instrumentation to measure amount of drainage water or flux within the vadose layer. We evaluated the performance and accuracy of automated passive capillary wick samplers (PCAPs) for ...
-
Environmental geochemistry of acid mine drainage water at Indus coal mine at Lakhra, Sindh Pakistan
International Nuclear Information System (INIS)
Siddique, I.; Shah, M.T.
2000-01-01
The annual coal production of Pakistan is about 3,637, 825 tones which is about 6% of the country's energy resources, out of this 1,241, 965 tones of coal was produced/ mined from the Lakhra coal field, District Dadu, Sindh which after the Thar coal field is the second largest coal field of Pakistan. At this coal field more than 58 mining companies are engaged in exploring the hidden wealth of the country. The problem of acid mine drainage, is caused by the passage or seepage of water, through mines where iron disulfides, usually pyrites, are exposed to the oxidizing action of water, air and bacteria, is the main problem faced by the mining companies. The geochemical analysis of acid mine drainage water collected from Indus coal mine no. 6 shows that beside its higher pH, total Dissolved Solids and Sulfates, it also posses higher amount of heavy metals like Cd, Cu, Pb, Co, Ni and Fe. This acid mine drainage water not only damages the mine structures but is also harmful to soil and ecology. (author)
-
Intermediate report on the problems of warm water drainage
International Nuclear Information System (INIS)
1976-01-01
The investigation into the solution of the problems of warm water drainage and its related matters was conducted, and the result was summarized by the warm water drainage sectional committee of the central public nuisance-prevention council entrusted by the Environment Agency. The first section of this report deals with the background of the warm water drainage problems. In December 1970, the environmental pollution prevention act was revised so as to include warm water drainage in the law. The second section deals with the progress of deliberation by the sectional committee. The third section deals with the actual conditions of warm water drainage. The temperature difference at the inlet and outlet of water was 5 to 11 0 C in power plants, 5 to 16 0 C in iron and steel works, 4 to 11 0 C in petroleum refineries, and 7 to 25 0 C in petrochemical plants. The amount of heat energy discharged from power plants was greater than that from the others. Other sections deal with its effects on the living things in water, the forecast of diffusion of warm drainage, the concept of the regulation of warm drainage, and the present countermeasure. Twelve points which require future investigation are listed. They are the change in the phases of living things affected by the change in temperature and flow of warm drainage, the effects on fishery resources, the estimation system for the environmental calorific capacity in the sea, the mechanism of diffusion and the forecasting method for the diffusion range. (Iwakiri, K.)
-
Microbial communities in riparian soils of a settling pond for mine drainage treatment.
Fan, Miaochun; Lin, Yanbing; Huo, Haibo; Liu, Yang; Zhao, Liang; Wang, Entao; Chen, Weimin; Wei, Gehong
2016-06-01
Mine drainage leads to serious contamination of soil. To assess the effects of mine drainage on microbial communities in riparian soils, we used an Illumina MiSeq platform to explore the soil microbial composition and diversity along a settling pond used for mine drainage treatment. Non-metric multidimensional scaling analysis showed that the microbial communities differed significantly among the four sampling zones (influent, upstream, downstream and effluent), but not seasonally. Constrained analysis of principal coordinates indicated heavy metals (zinc, lead and copper), total sulphur, pH and available potassium significantly influenced the microbial community compositions. Heavy metals were the key determinants separating the influent zone from the other three zones. Lower diversity indices were observed in the influent zone. However, more potential indicator species, related to sulphur and organic matter metabolism were found there, such as the sulphur-oxidizing genera Acidiferrobacter, Thermithiobacillus, Limnobacter, Thioprofundum and Thiovirga, and the sulphur-reducing genera Desulfotomaculum and Desulfobulbus; the organic matter degrading genera, Porphyrobacter and Paucimonas, were also identified. The results indicated that more microorganisms related to sulphur- and carbon-cycles may exist in soils heavily contaminated by mine drainage. Copyright © 2016 Elsevier Ltd. All rights reserved.
-
Early drainage mitigates methane and nitrous oxide emissions from organically amended paddy soils
DEFF Research Database (Denmark)
Tariq, Azeem; Jensen, Lars Stoumann; de Tourdonnet, Stephane
2017-01-01
Elevated greenhouse gas (GHG) emissions, particularly of methane (CH4) from flooded rice production systems contribute to global warming. Different crop management strategies, such as drainage of paddy soils and climate-smart residue management, are essential in order to mitigate GHG emissions from...... flooded rice systems, but they often conflict with practical management preferences.The aim of this study was to assess the potential of early-season drainage for mitigating CH4 and N2O emissions from soils with and without added organic amendments in relation to native soil organic carbon (SOC). Rice...
-
Acid drainage from coal mining: Effect on paddy soil and productivity of rice.
Choudhury, Burhan U; Malang, Akbar; Webster, Richard; Mohapatra, Kamal P; Verma, Bibhash C; Kumar, Manoj; Das, Anup; Islam, Mokidul; Hazarika, Samarendra
2017-04-01
Overburden and acid drainage from coal mining is transforming productive agricultural lands to unproductive wasteland in some parts of Northeast India. We have investigated the adverse effects of acid mine drainage on the soil of rice paddy and productivity by comparing them with non-mined land and abandoned paddy fields of Jaintia Hills in Northeast India. Pot experiments with a local rice cultivar (Myngoi) as test crop evaluated biological productivity of the contaminated soil. Contamination from overburden and acid mine drainage acidified the soil by 0.5 pH units, increased the exchangeable Al 3+ content 2-fold and its saturation on clay complexes by 53%. Available sulfur and extractable heavy metals, namely Fe, Mn and Cu increased several-fold in excess of critical limits, while the availability of phosphorus, potassium and zinc contents diminished by 32-62%. The grain yield of rice was 62% less from fields contaminated with acid mine drainage than from fields that have not suffered. Similarly, the amounts of vegetation, i.e. shoots and roots, in pots filled with soil from fields that received acid mine drainage were 59-68% less than from uncontaminated land (average shoot weight: 7.9±2.12gpot -1 ; average root weight: 3.40±1.15gpot -1 ). Paddy fields recovered some of their productivity 4years after mining ceased. Step-wise multiple regression analysis affirmed that shoot weight in the pots and grain yield in field were significantly (p<0.01) and positively influenced by the soil's pH and its contents of K, N and Zn, while concentration of S in excess of threshold limits in contaminated soil significantly (p<0.01) reduced the weight of shoots in the pots and grain yield in the field. Copyright © 2017 Elsevier B.V. All rights reserved.
-
Surface Water & Surface Drainage
Earth Data Analysis Center, University of New Mexico — This data set contains boundaries for all surface water and surface drainage for the state of New Mexico. It is in a vector digital data structure digitized from a...
-
4R Water Quality Impacts: An Assessment and Synthesis of Forty Years of Drainage Nitrogen Losses.
Christianson, L E; Harmel, R D
2015-11-01
The intersection of agricultural drainage and nutrient mobility in the environment has led to multiscale water quality concerns. This work reviewed and quantitatively analyzed nearly 1,000 site-years of subsurface tile drainage nitrogen (N) load data to develop a more comprehensive understanding of the impacts of 4R practices (application of the right source of nutrients, at the right rate and time, and in the right place) within drained landscapes across North America. Using drainage data newly compiled in the "Measured Annual Nutrient loads from AGricultural Environments" (MANAGE) database, relationships were developed across N application rates for nitrate N drainage loads and corn ( L.) yields. The lack of significant differences between N application timing or application method was inconsistent with the current emphasis placed on application timing, in particular, as a water quality improvement strategy ( = 0.934 and 0.916, respectively). Broad-scale analyses such as this can help identify major trends for water quality, but accurate implementation of the 4R approach will require site-specific knowledge to balance agronomic and environmental goals. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.
-
13 Morphometric Analysis of Ogunpa and Ogbere Drainage Basins ...
African Journals Online (AJOL)
`123456789jkl''''#
form and process of drainage basins that may be widely ... ferruginous tropical soil on basement complex rock (Areola ... landuse pattern control the infiltration loss, the distribution of ... the water intercepted by Ogbere drainage basin to longer ...
-
Qadir, M; Oster, J D
2004-05-05
Irrigation has long played a key role in feeding the expanding world population and is expected to play a still greater role in the future. As supplies of good-quality irrigation water are expected to decrease in several regions due to increased municipal-industrial-agricultural competition, available freshwater supplies need to be used more efficiently. In addition, reliance on the use and reuse of saline and/or sodic drainage waters, generated by irrigated agriculture, seems inevitable for irrigation. The same applies to salt-affected soils, which occupy more than 20% of the irrigated lands, and warrant attention for efficient, inexpensive and environmentally acceptable management. Technologically and from a management perspective, a couple of strategies have shown the potential to improve crop production under irrigated agriculture while minimizing the adverse environmental impacts. The first strategy, vegetative bioremediation--a plant-assisted reclamation approach--relies on growing appropriate plant species that can tolerate ambient soil salinity and sodicity levels during reclamation of salt-affected soils. A variety of plant species of agricultural significance have been found to be effective in sustainable reclamation of calcareous and moderately sodic and saline-sodic soils. The second strategy fosters dedicating soils to crop production systems where saline and/or sodic waters predominate and their disposal options are limited. Production systems based on salt-tolerant plant species using drainage waters may be sustainable with the potential of transforming such waters from an environmental burden into an economic asset. Such a strategy would encourage the disposal of drainage waters within the irrigated regions where they are generated rather than exporting these waters to other regions via discharge into main irrigation canals, local streams, or rivers. Being economically and environmentally sustainable, these strategies could be the key to future
-
Partitioning of Iron and Scandium in Soils Having Water Drainage Limitations
International Nuclear Information System (INIS)
Aide, M.; Braden, I.; Mueller, W.
2010-01-01
Soil chemistry of Fe includes weathering reactions, adsorption, hydrolysis, complexation, and oxidation-reduction reactions. Soil chemistry for scandium (Sc) is similar, but Sc does not include oxidation-reduction reactions. To determine if geochemical analysis may be used to identify Sc partitioning with respect to Fe among the particle size fractions, two Alfisol and two Ultisol soils were assessed using an aqua-regia digestion to estimate Sc and Fe concentrations for whole soil and particle size separates. Aqua-regia digestion data showed Sc depletion relative to Fe in sand separate. Sand separate is largely composed on quartz sand and Fe-Mn-bearing nodules, which are redoximorphic features produced by alternating oxic and suboxic/anoxic conditions associated with seasonally fluctuating water tables. Relative partitioning of Fe and Sc in these soils warrants further study to assess if selective extractions could quantify the extent of modern or ancestral oxidation-reduction processes responsible in some soil features involved in soil genesis.
-
International Nuclear Information System (INIS)
Azhar, A.H.; Alam, M.M; Rafiq, M.
2005-01-01
A simple user-friendly menu-driven database management system pertinent to the Impact of Subsurface Drainage Systems on land and Water Conditions (ISLaW) has been developed for use in water logging and salinity management issues of drainage areas. This database has been developed by integrating four software viz; Microsoft Excel, MS Word, Acrobat and MS Access. The information in the form of tables and figures with respect to various drainage projects has been presented in MS Word files. The major data sets of various subsurface drainage projects included in the ISLaW database are: i) technical aspects, ii) groundwater and soil salinity aspects, iii) socio-technical aspects, iv) agro-economic aspects, and v) operation and maintenance aspects. The various ISLaW files can be accessed just by clicking at the Menu buttons of the database system. This database not only gives feedback on the functioning of different subsurface drainage projects with respect to above mentioned various aspects, but also serves as a resource document for these data for future studies at other drainage projects. The developed database system is useful for planners, designers and Farmers' Organizations for improved operation of existing as well as development of future drainage projects. (author)
-
Rozemeijer, J. C.; Visser, A.; Borren, W.; Winegram, M.; van der Velde, Y.; Klein, J.; Broers, H. P.
2016-01-01
High nitrogen (N) and phosphorus (P) fluxes from upstream agriculture threaten aquatic ecosystems in surface waters and estuaries, especially in areas characterized by high agricultural N and P inputs and densely drained catchments like the Netherlands. Controlled drainage has been recognized as an effective option to optimize soil moisture conditions for agriculture and to reduce unnecessary losses of fresh water and nutrients. This is achieved by introducing control structures with adjustable overflow levels into subsurface tube drain systems. A small-scale (1 ha) field experiment was designed to investigate the hydrological and chemical changes after introducing controlled drainage. Precipitation rates and the response of water tables and drain fluxes were measured in the periods before the introduction of controlled drainage (2007-2008) and after (2009-2011). For the N and P concentration measurements, auto-analyzers for continuous records were combined with passive samplers for time-averaged concentrations at individual drain outlets. The experimental setup enabled the quantification of changes in the water and solute balance after introducing controlled drainage. The results showed that introducing controlled drainage reduced the drain discharge and increased the groundwater storage in the field. To achieve this, the overflow levels have to be elevated in early spring, before the drain discharge stops due to dryer conditions and falling groundwater levels. The groundwater storage in the field would have been larger if the water levels in the adjacent ditch were controlled as well by an adjustable weir. The N concentrations and loads increased, which was largely related to elevated concentrations in one of the three monitored tube drains. The P loads via the tube drains reduced due to the reduction in discharge after introducing controlled drainage. However, this may be counteracted by the higher groundwater levels and the larger contribution of N- and P
-
Directory of Open Access Journals (Sweden)
A. Nahuel A. Pachas
2016-09-01
Full Text Available Water use and depth of water extraction of leucaena (Leucaena leucocephala and Rhodes grass (Chloris gayana pasture, irrigated with desalinated coal seam water (a by-product of the coal seam gas industry, were monitored to provide background information on root activity, spatial and temporal water use and deep drainage over a 757-day period from August 2011 to August 2013. Methodology comprised measurement of soil water from surface to 4 m depth using 8 EnviroSCAN probes connected to dataloggers positioned within leucaena twin rows and within the Rhodes grass inter-row. Just over 581,000 individual moisture measurements were collated and are reported here. Water extraction (and by inference root activity of leucaena and Rhodes grass showed marked seasonal fluctuation with deepest and highest water extraction occurring during the first growing season; water extraction was greatly diminished during the following drier and cooler seasons due to the negative influences of lower soil moisture contents, lower temperatures and increased defoliation on pasture growth. The highest values of deep drainage below 4 m depth occurred when high rainfall events corresponded with high soil water storage in the entire profile (0–4 m depth. Given that water usage by both leucaena and Rhodes grass was greatest in the upper layers of soil (<1.5 m, future research should focus on how the level of competitive interaction might be managed by choice of row spacing and frequency of irrigation. Further studies are needed, including: (a physical sampling to determine the depth of active roots; (b how defoliation affects rooting behaviours and water use of leucaena; and (c modelling of the water and salt balances of leucaena and grass inter-row systems using data from this study, with various levels of irrigation, to investigate the risks of deep drainage over an extended climate sequence.Keywords: Active rooting depth, agroforestry, Chloris gayana, Leucaena leucocephala
-
Reuse of drainage water model : calculation method of drainage water and watertable depth
Roest, C.W.J.; Rijtema, P.E.; Abdel Khalik, M.A.
1986-01-01
The main objective of the project is to assist the Ministry of Irrigation in Egypt in the planning of future watermanagement strategies incorporating reuse of drainage water practices. In order to achieve this main objective a comprehensive measurement programme has been initiated and a mathematical
-
Directory of Open Access Journals (Sweden)
M. I. Stutter
2004-01-01
Full Text Available An experiment comparing effects of sulphuric acid and reduced N deposition on soil water quality and on chemical and physical growth indicators for forest ecosystems is described. Six H2SO4 and (NH42SO4 treatment loads, from 0 – 44 and 0 – 25 kmolc ha-1 yr-1, respectively, were applied to outdoor microcosms of Pinus sylvestris seedlings in 3 acid to intermediate upland soils (calc-silicate, quartzite and granite for 2 years. Different soil types responded similarly to H2SO4 loads, resulting in decreased leachate pH, but differently to reduced N inputs. In microcosms of calc-silicate soil, nitrification of NH4 resulted in lower pH and higher cation leaching than in acid treatments. By contrast, in quartzite and granite soils, (NH42SO4 promoted direct cation leaching, although leachate pH increased. The results highlighted the importance of soil composition on the nature of the cations leached, the SO4 adsorption capacities and microbial N transformations. Greater seedling growth on calc-silicate soils under both treatment types was related to sustained nutrient availability. Reductions in foliar P and Mg with higher N treatments were observed for seedlings in the calc-silicate soil. There were few treatment effects on quartzite and granite microcosm tree seedlings since P limitation precluded seedling growth responses to treatments. Hence, any benefits of N deposition to seedlings on quartzite and granite soils appeared limited by availability of co-nutrients, exacerbated by rapid depletion of soil exchangeable base cations. Keywords: acidification, manipulation, nitrogen, ammonium, deposition, soil, drainage, pine, microcosms, forest
-
DEFF Research Database (Denmark)
Granier, A.; Reichstein, M.; Breda, N.
2007-01-01
stand to estimate the water balance terms: trees and understorey transpiration, rainfall interception, throughfall, drainage in the different soil layers and soil water content. This model calculated the onset date, duration and intensity of the soil water shortage (called water stress) using measured...... measured and modelled soil water content. Our analysis showed a wide spatial distribution of drought stress over Europe, with a maximum intensity within a large band extending from Portugal to NE Germany. Vapour fluxes in all the investigated sites were reduced by drought, due to stomatal closure, when...... the relative extractable water in soil (REW) dropped below ca. 0.4. Rainfall events during the drought, however, typically induced rapid restoration of vapour fluxes. Similar to the water vapour fluxes, the net ecosystem production decreased with increasing water stress at all the sites. Both gross primary...
-
Biofuel as an Integrated Farm Drainage Management crop: A bioeconomic analysis
Levers, L. R.; Schwabe, K. A.
2017-04-01
Irrigated agricultural lands in arid regions often suffer from soil salinization and lack of drainage, which affect environmental quality and productivity. Integrated Farm Drainage Management (IFDM) systems, where drainage water generated from higher-valued crops grown on high quality soils are used to irrigate salt-tolerant crops grown on marginal soils, is one possible strategy for managing salinity and drainage problems. If the IFDM crop were a biofuel crop, both environmental and private benefits may be generated; however, little is known about this possibility. As such, we develop a bioeconomic programming model of irrigated agricultural production to examine the role salt-tolerant biofuel crops might play within an IFDM system. Our results, generated by optimizing profits over land, water, and crop choice decisions subject to resource constraints, suggest that based on the private profits alone, biofuel crops can be a competitive alternative to the common practices of land retirement and nonbiofuel crop production under both low to high drainage water salinity. Yet IFDM biofuel crop production generates 30-35% fewer GHG emissions than the other strategies. The private market competitiveness coupled with the public good benefits may justify policy changes encouraging the growth of IFDM biofuel crops in arid agricultural areas globally.
-
Irrigation and drainage in agriculture: a salinity and environmental perspective
Zee, van der S.E.A.T.M.; Stofberg, S.F.; Yang, X.; Liu, Y.; Islam, M.N.; Hu, Yin Fei
2017-01-01
Whereas irrigation and drainage are intended to address the shortage and surplus of soil water, respectively, an important aspect to address is also the management of salinity. Plants have a limited tolerance for soil water salinity, and despite significant gaps in our practical knowledge, an
-
Chiu, C.; Bowling, L. C.
2011-12-01
The Wabash River watershed is the largest watershed in Indiana and includes the longest undammed river reach east of the Mississippi River. The land use of the Wabash River basin began to significantly change from mixed woodland dominated by small lakes and wetlands to agriculture in the mid-1800s and agriculture is now the predominant land use. Over 80% of natural wetland areas were drained to facilitate better crop production through both surface and subsurface drainage applications. Quantifying the change in hydrologic response in this intensively managed landscape requires a hydrologic model that can represent wetlands, crop growth, and impervious area as well as subsurface and surface drainage enhancements, coupled with high resolution soil and topographic inputs. The Variable Infiltration Capacity (VIC) model wetland algorithm has been previously modified to incorporate spatially-varying estimates of water table distribution using a topographic index approach, as well as a simple urban representation. Now, the soil water characteristics curve and a derived drained to equilibrium moisture profile are used to improve the model's estimation of the water table. In order to represent subsurface (tile) drainage, the tile drainage component of subsurface flow is calculated when the simulated water table rises above a specified drain depth. A map of the current estimated extent of subsurface tile drainage for the Wabash River based on a decision tree classifier of soil drainage class, soil slope and agricultural land use is used to activate the new tile drainage feature in the VIC model, while wetland depressional storage capacity is extracted from digital elevation and soil information. This modified VIC model is used to evaluate the performance of model physical variations in the intensively managed hydrologic regime of the Wabash River system and to understand the role of surface and subsurface storage, and land use and land cover change on hydrologic change.
-
Monitoring and remediation technologies of organochlorine pesticides in drainage water
Directory of Open Access Journals (Sweden)
Ismail Ahmed
2015-03-01
Full Text Available This study was carried out to monitor the presence of organochlorine in drainage water in Kafr-El-Sheikh Governorate, Egypt. Furthermore, to evaluate the efficiencies of different remediation techniques (advanced oxidation processes [AOPs] and bioremediation for removing the most frequently detected compound (lindane in drainage water. The results showed the presence of several organochlorine pesticides in all sampling sites. Lindane was detected with high frequency relative to other detected organochlorine in drainage water. Nano photo-Fenton like reagent was the most effective treatment for lindane removal in drainage water. Bioremediation of lindane by effective microorganisms (EMs removed 100% of the lindane initial concentration. There is no remaining toxicity in lindane contaminated-water after remediation on treated rats relative to control with respect to histopathological changes in liver and kidney. Advanced oxidation processes especially with nanomaterials and bioremediation using effective microorganisms can be regarded as safe and effective remediation technologies of lindane in water.
-
Frey, Steven K; Topp, Edward; Khan, Izhar U H; Ball, Bonnie R; Edwards, Mark; Gottschall, Natalie; Sunohara, Mark; Lapen, David R
2015-11-01
This work investigated chlortetracycline, tylosin, and tetracycline (plus transformation products), and DNA-based quantitative Campylobacter spp. and Campylobacter tetracycline antibiotic resistant genes (tet(O)) in tile drainage, groundwater, and soil before and following a liquid swine manure (LSM) application on clay loam plots under controlled (CD) and free (FD) tile drainage. Chlortetracycline/tetracycline was strongly bound to manure solids while tylosin dominated in the liquid portion of manure. The chlortetracycline transformation product isochlortetracycline was the most persistent analyte in water. Rhodamine WT (RWT) tracer was mixed with manure and monitored in tile and groundwater. RWT and veterinary antibiotic (VA) concentrations were strongly correlated in water which supported the use of RWT as a surrogate tracer. While CD reduced tile discharge and eliminated application-induced VA movement (via tile) to surface water, total VA mass loading to surface water was not affected by CD. At both CD and FD test plots, the biggest 'flush' of VA mass and highest VA concentrations occurred in response to precipitation received 2d after application, which strongly influenced the flow abatement capacity of CD on account of highly elevated water levels in field initiating overflow drainage for CD systems (when water level tile and groundwater became very low within 10d following application. Both Campylobacter spp. and Campylobacter tet(O) genes were present in groundwater and soil prior to application, and increased thereafter. Unlike the VA compounds, Campylobacter spp. and Campylobacter tet(O) gene loadings in tile drainage were reduced by CD, in relation to FD. Crown Copyright © 2015. Published by Elsevier B.V. All rights reserved.
-
International Nuclear Information System (INIS)
Silva, Camila Goncalves Bof
2010-01-01
Phosphogypsum is a waste generated in phosphoric acid production by the 'wet process'. The immense amount of phosphogypsum yearly produced (around 150 million tons) is receiving attention from environmental protection agencies all over the word, given its potential of contamination. In Brazil, this material has been used for many decades, especially for agricultural application on cropland. Although the phosphogypsum is mainly composed of dehydrated calcium sulfate, it can have high levels of impurities, such as metals (Cd, Cr, Cu, Pb), non-metals (As and Se) and radioactive elements from natural series of 232 Th and 238 U. Therefore, its continuous application as an agricultural agent can result not just in soil contamination, but also contamination of the surface and groundwater due to the runoff and infiltration process. The concern associated with the contamination of aquatic environments increases; when water is used for human consumption, requiring progressive adoption of more restrictive limits. However, some of the conventional analytical techniques used to determine the maximum limit of contaminants in water have detection limits above the maximum limits established by the environmental legislation. This work was aimed to evaluate the mobility of metals and non-metals in soils and, consequently, the contamination of drainage water through greenhouse-scale leaching and transport of toxic elements from soils fertilized with phosphogypsum. Hence, methods were studied and implemented for determination of metals (Cd, Cr, Cu and Pb) using Furnace Graphite Atomic Absorption Spectrometry (GF AAS), as well as for non-metals (As and Se) using Inductively Coupled Plasma Mass Spectrometry (lCP-MS). Effects of different chemical modifiers on the determination of Cd, Cr, Cu and Pb concentration by GF AAS were also investigated. In general, it was observed that the metal and non-metal concentration were below than the actual detection limit of the equipment for all
-
Heikkinen, P.M.; Raisanen, M.L.; Johnson, R.H.
2009-01-01
Seepage water and drainage water geochemistry (pH, EC, O2, redox, alkalinity, dissolved cations and trace metals, major anions, total element concentrations) were studied at two active sulphide mine tailings impoundments in Finland (the Hitura Ni mine and Luikonlahti Cu mine/talc processing plant). The data were used to assess the factors influencing tailings seepage quality and to identify constraints for water treatment. Changes in seepage water quality after equilibration with atmospheric conditions were evaluated based on geochemical modelling. At Luikonlahti, annual and seasonal changes were also studied. Seepage quality was largely influenced by the tailings mineralogy, and the serpentine-rich, low sulphide Hitura tailings produced neutral mine drainage with high Ni. In contrast, drainage from the high sulphide, multi-metal tailings of Luikonlahti represented typical acid mine drainage with elevated contents of Zn, Ni, Cu, and Co. Other factors affecting the seepage quality included weathering of the tailings along the seepage flow path, process water input, local hydrological settings, and structural changes in the tailings impoundment. Geochemical modelling showed that pH increased and some heavy metals were adsorbed to Fe precipitates after net alkaline waters equilibrated with the atmosphere. In the net acidic waters, pH decreased and no adsorption occurred. A combination of aerobic and anaerobic treatments is proposed for Hitura seepages to decrease the sulphate and metal loading. For Luikonlahti, prolonged monitoring of the seepage quality is suggested instead of treatment, since the water quality is still adjusting to recent modifications to the tailings impoundment.
-
Testing of DRAINMOD for Forested Watersheds with Non-Pattern Drainage
Devendra M. Amatya; Ge Sun; R. Wayne Skaggs; Carl C. Trettin
2003-01-01
Models like DRAINMOD and its forestry version, DRAINLOB, have been specifically developed as a field scale model for evaluating hydrologic effects of crops (trees), soil, and water management practices for lands with pattern drainage (i.e. with parallel ditches) on relatively flat, high water table soils. These models conduct a water balance between the ditches to...
-
Smith, Erik A.; Sanocki, Chris A.; Lorenz, David L.; Jacobsen, Katrin E.
2017-12-27
Streamflow distribution maps for the Cannon River and St. Louis River drainage basins were developed by the U.S. Geological Survey, in cooperation with the Legislative-Citizen Commission on Minnesota Resources, to illustrate relative and cumulative streamflow distributions. The Cannon River was selected to provide baseline data to assess the effects of potential surficial sand mining, and the St. Louis River was selected to determine the effects of ongoing Mesabi Iron Range mining. Each drainage basin (Cannon, St. Louis) was subdivided into nested drainage basins: the Cannon River was subdivided into 152 nested drainage basins, and the St. Louis River was subdivided into 353 nested drainage basins. For each smaller drainage basin, the estimated volumes of groundwater discharge (as base flow) and surface runoff flowing into all surface-water features were displayed under the following conditions: (1) extreme low-flow conditions, comparable to an exceedance-probability quantile of 0.95; (2) low-flow conditions, comparable to an exceedance-probability quantile of 0.90; (3) a median condition, comparable to an exceedance-probability quantile of 0.50; and (4) a high-flow condition, comparable to an exceedance-probability quantile of 0.02.Streamflow distribution maps were developed using flow-duration curve exceedance-probability quantiles in conjunction with Soil-Water-Balance model outputs; both the flow-duration curve and Soil-Water-Balance models were built upon previously published U.S. Geological Survey reports. The selected streamflow distribution maps provide a proactive water management tool for State cooperators by illustrating flow rates during a range of hydraulic conditions. Furthermore, after the nested drainage basins are highlighted in terms of surface-water flows, the streamflows can be evaluated in the context of meeting specific ecological flows under different flow regimes and potentially assist with decisions regarding groundwater and surface-water
-
Passive Microwave Observation of Soil Water Infiltration
Jackson, Thomas J.; Schmugge, Thomas J.; Rawls, Walter J.; ONeill, Peggy E.; Parlange, Marc B.
1997-01-01
Infiltration is a time varying process of water entry into soil. Experiments were conducted here using truck based microwave radiometers to observe small plots during and following sprinkler irrigation. Experiments were conducted on a sandy loam soil in 1994 and a silt loam in 1995. Sandy loam soils typically have higher infiltration capabilities than clays. For the sandy loam the observed brightness temperature (TB) quickly reached a nominally constant value during irrigation. When the irrigation was stopped the TB began to increase as drainage took place. The irrigation rates in 1995 with the silt loam soil exceeded the saturated conductivity of the soil. During irrigation the TB values exhibited a pattern that suggests the occurrence of coherent reflection, a rarely observed phenomena under natural conditions. These results suggested the existence of a sharp dielectric boundary (wet over dry soil) that was increasing in depth with time.
-
Diminishing freshwater resources have brought attention to the reuse of degraded water as a water resource rather than a disposal problem. Drainage water from tile-drained, irrigated agricultural land is degraded water that is often in large supply, but the long-term impact and sustainability of it...
-
Deep drainage modeling for a fertigated coffee plantation in the brazilian savanna
Pinto, Victor Meriguetti; Reichardt, Klaus; Dam, van Jos; Lier, Quirijn D.J.V.; Bruno, Isabeli Pereira; Durigon, Angelica; Dourado-Neto, Durval; Bortolotto, Rafael Pivotto
2015-01-01
Modeling in agriculture represents an important tool to understand processes as water and nutrient losses by drainage, or to test different conditions and scenarios of soil and crop management. Among the existing computational models to describe hydrological processes, SWAP (Soil, Water,
-
Ion activity and distribution of heavy metals in acid mine drainage polluted subtropical soils
International Nuclear Information System (INIS)
Li Yongtao; Becquer, Thierry; Dai Jun; Quantin, Cecile; Benedetti, Marc F.
2009-01-01
The oxidative dissolution of mine wastes gives rise to acidic, metal-enriched mine drainage (AMD) and has typically posed an additional risk to the environment. The poly-metallic mine Dabaoshan in South China is an excellent test site to understand the processes affecting the surrounding polluted agricultural fields. Our objectives were firstly to investigate metal ion activity in soil solution, distribution in solid constituents, and spatial distribution in samples, secondly to determine dominant environment factors controlling metal activity in the long-term AMD-polluted subtropical soils. Soil Column Donnan Membrane Technology (SC-DMT) combined with sequential extraction shows that unusually large proportion of the metal ions are present as free ion in the soil solutions. The narrow range of low pH values prevents any pH effects during the binding onto oxides or organic matter. The differences in speciation of the soil solutions may explain the different soil degradation observed between paddy and non-paddy soils. - First evidence of the real free metal ion concentrations in acid mine drainage context in tropical systems
-
Kim, Jae Gon
2017-04-01
Oxidation of sulfides produces acid rock drainage (ARD) upon their exposure to oxidation environment by construction and mining activities. The ARD causes the acidification and metal contamination of soil, surface water and groundwater, the damage of plant, the deterioration of landscape and the reduction of slope stability. The revegetation of slope surface is one of commonly adopted strategies to reduce erosion and to increase slope stability. However, the revegetation of the ARD producing slope surface is frequently failed due to its high acidity and toxic metal content. We developed a revegetation method consisting of microencapsualtion and artificial soil in the laboratory. The revegetation method was applied on the ARD producing slope on which the revegetation using soil coverage and seeding was failed and monitored the plant growth for one year. The phosphate solution was applied on sulfide containing rock to form stable Fe-phosphate mineral on the surface of sulfide, which worked as a physical barrier to prevent contacting oxidants such as oxygen and Fe3+ ion to the sulfide surface. After the microencapsulation, two artificial soil layers were constructed. The first layer containing organic matter, dolomite powder and soil was constructed at 2 cm thickness to neutralize the rising acidic capillary water from the subsurface and to remove the dissolved oxygen from the percolating rain water. Finally, the second layer containing seeds, organic matter, nutrients and soil was constructed at 3 cm thickness on the top. After application of the method, the pH of the soil below the artificial soil layer increased and the ARD production from the rock fragments reduced. The plant growth showed an ordinary state while the plant died two month after germination for the previous revegetation trial. No soil erosion occurred from the slope during the one year field test.
-
Institute of Scientific and Technical Information of China (English)
武强; 董东林; 石占华; 武雄; 孙卫东; 叶责钧; 李树文; 刘金韬
2000-01-01
The conflict among water drainage, water supply and eco-environment protection is getting more and more serious due to the irrational drainage and exploitation of ground water resources in coal-accumulated basins of North China. Efficient solutions to the conflict are to maintain long-term dynamic balance between input and output of the ground water basins, and to try to improve resourcification of the mine water. All solutions must guarantee the eco-environment quality. This paper presents a new idea of optimum combination of water drainage, water supply and eco-environment protection so as to solve the problem of unstable mine water supply, which is caused by the changeable water drainage for the whole combination system. Both the management of hydraulic techniques and constraints in economy, society, ecology, environment, industrial structural adjustments and sustainable developments have been taken into account. Since the traditional and separate management of different departments of water drainage,
-
Drainage treatment technology for water pollution prevention
Energy Technology Data Exchange (ETDEWEB)
Ebise, Sen' ichi
1988-03-01
Drainage is purified either at terminal treatment plants or by septic tanks for sewage. At terminal treatment plants, sewage is purified by activated sludge prosessing or by biological treatment equipment. By the normal activated sludge processing, only 20 - 30 % of nitrogen and phosphur can be removed. To solve this problem, many advanced processing systems have been employed, representative systems being coagulating sedimentation, rapid filtration, recirculating nitro-denitrification, etc. The coagulating sedimentation is a treatment process in which such metallic salt coagulations as aluminum, iron, etc. are injected and mixed with sewage, and then phosphur and the like are sedimented in the form of grains. The rapid filtration requires no large space, and can reliably remove suspended matter. For large scale septic tank processing system, advance treatment processing is supplemented to improve the quality of treated water. Among other systems of sewage purification are oxidized channel, oxidized pond, soil treatment, etc. (2 figs, 2 refs)
-
Mapping Drainage Classes in Denmark by Means of Decision Tree Classification
DEFF Research Database (Denmark)
Møller, Anders Bjørn; Iversen, Bo Vangsø; Beucher, Amélie
Soil drainage, understood as the removal of excess water from the soil matrix, plays an integral role in the environment and land use. It affects plant growth, soil biota, the leaching of nutrients and other solutes, the release of greenhouse gasses and the risk of soil compaction and surface ero...
-
Water sensors with cellular system eliminate tail water drainage in alfalfa irrigation
Directory of Open Access Journals (Sweden)
Rajat Saha
2011-10-01
Full Text Available Alfalfa is the largest consumer of water among all crops in California. It is generally flood-irrigated, so any system that decreases runoff can improve irrigation efficiency and conserve water. To more accurately manage the water flow at the tail (bottom end of the field in surface-irrigated alfalfa crops, we developed a system that consists of wetting-front sensors, a cellular communication system and a water advance model. This system detects the wetting front, determines its advance rate and generates a cell-phone alert to the irrigator when the water supply needs to be cut off, so that tail water drainage is minimized. To test its feasibility, we conducted field tests during the 2008 and 2009 alfalfa growing seasons. The field experiments successfully validated the methodology, producing zero tail water drainage.
-
Drainage, liming and fertilization of organic soils. 1. Long-term effects on acid/base relations
International Nuclear Information System (INIS)
Braekke, F.H.
1999-01-01
Long-term changes of the acid/base relations of organic soils after drainage, fertilization and/or liming at three experimental sites - two ombrogenous and one soligenous - in south-central Norway are discussed. These sites were drained, fertilized and/or limed in 1953-1956 and sampled in 1991-1992. Drainage at the ombrogenous sites caused: insignificant shifts of pH, higher bulk densities to 40 cm depth, higher ash percentage, higher contents of N and P to 20 cm depth and reduced concentrations of total Ca, K, Mg, Na, Al and Fe in soil layers deeper than 20 cm. The soligenous site was not effectively drained; despite this, pH dropped about 0.5 unit in the surface and subsurface soil layers of the control plots, while small changes were measured for most other soil variables. The suggested reason for the pH drop is limited sulphide oxidation in the upper 20 cm drained layer. Base saturation at actual soil pH, when all treatments were included, was estimated with good precision by four regressors: pH, extractable Al, extractable Fe and extractable Ca (R 2 = 0.90-0.95). Similar models explained 97-99% of the variation in base saturation at soil pH = 7.0. The lime effects at the properly drained oligotrophic sites were proportional to applied doses; for pH to 40 cm, base saturation to 60 cm, and Ca concentration to 60 cm depth. At the less well-drained soligenous site, effects were limited to the upper 30 cm layer. Both drainage and liming caused higher cation exchange capacities and proper drainage seems to be a prerequisite for the liming effect. Estimated recovery of calcium to 60 cm depth was 64-79% at the ombrogenous sites and 42-46% at the soligenous site 28 refs, 3 figs, 8 tabs
-
Tile drainage phosphorus loss with long-term consistent cropping systems and fertilization.
Zhang, T Q; Tan, C S; Zheng, Z M; Drury, C F
2015-03-01
Phosphorus (P) loss in tile drainage water may vary with agricultural practices, and the impacts are often hard to detect with short-term studies. We evaluated the effects of long-term (≥43 yr) cropping systems (continuous corn [CC], corn-oats-alfalfa-alfalfa rotation [CR], and continuous grass [CS]) and fertilization (fertilization [F] vs. no-fertilization [NF]) on P loss in tile drainage water from a clay loam soil over a 4-yr period. Compared with NF, long-term fertilization increased concentrations and losses of dissolved reactive P (DRP), dissolved unreactive P (DURP), and total P (TP) in tile drainage water, with the increments following the order: CS > CR > CC. Dissolved P (dissolved reactive P [DRP] and dissolved unreactive P [DURP]) was the dominant P form in drainage outflow, accounting for 72% of TP loss under F-CS, whereas particulate P (PP) was the major form of TP loss under F-CC (72%), F-CR (62%), NF-CS (66%), NF-CC (74%), and NF-CR (72%). Dissolved unreactive P played nearly equal roles as DRP in P losses in tile drainage water. Stepwise regression analysis showed that the concentration of P (DRP, DURP, and PP) in tile drainage flow, rather than event flow volume, was the most important factor contributing to P loss in tile drainage water, although event flow volume was more important in PP loss than in dissolved P loss. Continuous grass significantly increased P loss by increasing P concentration and flow volume of tile drainage water, especially under the fertilization treatment. Long-term grasslands may become a significant P source in tile-drained systems when they receive regular P addition. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.
-
Acid mine drainage: mining and water pollution issues in British Columbia
Energy Technology Data Exchange (ETDEWEB)
NONE
1998-12-31
The importance of protecting water quality and some of the problems associated with mineral development are described. Negative impacts of mining operations such as sedimentation, water disturbances, and water pollution from waste rock and tailings are considered. Mining wastes, types of water pollution from mining, the legacy of acid mine drainage, predicting acid mine drainage, preventing and mitigating acid mine drainage, examples from the past, and cyanide heap-leaching are discussed. The real costs of mining at the Telkwa open pit coal mine are assessed. British Columbia mines that are known for or are potentially acid generating are shown on a map. 32 refs., 10 figs.
-
Hagedorn, J.; Zhu, Q.; Davidson, E. A.; Castro, M.
2017-12-01
Managing resources wisely while reducing environmental impact is the backbone of agricultural sustainability. Agricultural practices must develop strategies to effectively reduce nutrient runoff from farmed lands. Preliminary research suggests that one such strategy is drainage water management by which water levels are intentionally elevated following fertilization to favor subsoil denitrification and thereby reduce nitrogen leaching into groundwater and streams. Despite documented success in nitrate reduction, this best management practice (BMP) has not been widely adopted in part because users are not aware of the potential. But before extension agencies begin promoting this practice, evaluation of unintentional consequences must be studied. There is a risk that by elevating water levels for the purpose of creating suitable conditions for denitrification, more potent greenhouse gases such as nitrous oxide (N2O) and methane (CH4) could be produced, in which case the practice would be swapping one form of pollution for another. A multi-scale experimental design, using soil chambers and a tower-based gradient method, was implemented in a drainage water managed corn-soybean system on the Eastern Shore of Maryland. Emissions, soil moisture content, and soil nitrate measurements have been collected and analyzed to evaluate for differences between treatment and control plots as standard farm management practices, such as fertilization, occur. Preliminary results based on monthly sampling of transects of stationary soil chambers characterize the spatial heterogeneity of the fields and reveal that there are detectable differences in N2O and CH4 emissions between fields. There are also significant relationships between soil moisture, soil nitrate content and N2O emissions. The tower-based gradient method with micrometerological measurements provides high temporal resolution at the full field scale that complements the soil chamber work. This multi-scale resolution balance
-
Accelerating transient drainage from UMTRA Project tailings piles
International Nuclear Information System (INIS)
1990-09-01
The period between the completion of construction of the tailings disposal cell and the establishment of equilibrium moisture content and seepage conditions is considered to be the period of transient drainage. Transient drainage may be due to factors such as construction water, precipitation, or residual water from the milling process. Transient seepage rates usually exceed steady state seepage rates. If the transient seepage rate causes contaminant levels to exceed groundwater compliance standards, then an alternative groundwater compliance strategy or technical approach to reduce or mitigate the effects of the drainage must be adopted. This study examines methods to accelerate the transient drainage of soils and hence to remove excess pore water from tailings in UMTRA Project disposal cells. The technical and economic feasibility of possible methods is examined. In order to perform comparative economical analyses of the various methods, an example tailings pile is postulated. This pile is considered to be 300 meters by 300 meters by 10 meters in thickness
-
Directory of Open Access Journals (Sweden)
Hanan E.M. El Azab
2015-12-01
Full Text Available The study area was selected in El Saf District of El Giza Governorate in Egypt, covering 21461.4 ha of Nile sediments and their outskirts of alluvial higher and lower terraces. The aim of this study was to assess the impact of informal irrigation practices on drainage deterioration, soil pollution and land suitability for agricultural use using the satellite LDCM data 2013. From the lower alluvial terraces (partly cultivated using wastewater, the drainage flows westward via descending slopes resulting in land deterioration in both the alluvial lower terraces and alluvial plain of River Nile. The drainage conditions are excessively drained soils in the alluvial upper terraces within soils of Typic Haplocalcids, sandy skeletal, but in the lower terraces it partly occurred within soils of Typic Torriorthents, sandy skeletal. Moderately well drained soils occurred in soils of Typic Torriorthents, sandy in the alluvial lower terraces, while in the alluvial plain of Nile sediments are Sodic Haplotorrerts, fine. Poorly drained soils in the lower alluvial terraces have soils of Typic Epiaquents, sandy associated with Sodic Psammaquents and Aquic Haplocalcids, coarse loamy, while in the alluvial plain of River Nile the soils are Halic Epiaquerts, fine. Very poorly drained soils (submerged areas are scattered spots in both the lower alluvial terraces and the alluvial plain. In the alluvial plain of River Nile, 1967.1 ha become not suitable for the traditional cultivated crops, while in the alluvial terraces 3251.0 ha are not suitable for the proposed cultivation of Jojoba plants. Heavy metals of Cadmium (Cd, Cobalt (Co, Lead (Pb and Nickel (Ni were added to the soil surface and sub-surface in the irrigated areas by wastewater in the lower alluvial terraces (moderately well drained soils, but Cd and Co exceeded the standards of permissible total concentrations in these soils. The same metals were added to soil sub-surface layers in the alluvial plain
-
Directory of Open Access Journals (Sweden)
V. Moca
2006-10-01
Full Text Available In the pedo-climatic conditions of Suceava County that extends on a total surface of 855 300 ha, the balance of agricultural land affected by humidity excess with temporar or permanent character is differenciated from south to north and from east to west, between 30 % till 40%, which means almost 100 000 ha. On these soils with underground water or pluvial excess hydro ameliorative drainage systems have been installed, associated to a complex agroameliorative works. For long effect estimation of the underground drainage asociated with the agropedoameliorative works upon the some physical and hydrophysical characteristics, there were analyzed the soil and the environment conditions from Baia field. For this reason, we analyzed the agrophysical conditions for luvisol albic pseudogleic (SRCS-1980, respectively luvosol albic stagnic-glosic (SRTS-2003 albic luvosoil drained and cultivated, after a period of 28 years (1978-2006 use. The obtained data regarding to te water balance and the evolution of the major physical properties of soil, under the influence of drainage and amelioration works, put into evidence in the first stage (1978-1986 a general improvement of the aerohidrycal state and physical-chemical conditioning. In the next two experimental cycles of 10 years each, have been noticed a increased of compaction degree of soil drained and cultivated on 0-30 cm depth, from weak loose to moderately compaction depending on the remanence of the reclamation technologies.
-
Time effects of water drainage from deposited back-fill
International Nuclear Information System (INIS)
Baranski, L.A.
1976-01-01
Time effects of water drainage from deposited back-fill in mine excavations are considered. The time dependence of drainage from the deposited material was determined from ''in situ'' measurements with the aid of radioisotope gauges. The measurements were performed for given drainage conditions and practically constant grain size composition. It was found that in a few hours after the end of the back-filling operation the mechanical properties of the deposited material are practically constant. (author)
-
Butler, D.L.; Wright, W.G.; Stewart, K.C.; Osmundson, B.C.; Krueger, R.P.; Crabtree, D.W.
1996-01-01
In 1985, the U.S. Department of the Interior began a program to study the effects of irrigation drainage in the Western United States. These studies were done to determine whether irrigation drainage was causing problems related to human health, water quality, and fish and wildlife resources. Results of a study in 1991-93 of irrigation drainage associated with the Uncompahgre Project area, located in the lower Gunnison River Basin, and of the Grand Valley, located along the Colorado River, are described in this report. The focus of the report is on the sources, distribution, movement, and fate of selenium in the hydrologic and biological systems and the effects on biota. Generally, other trace- constituent concentrations in water and biota were not elevated or were not at levels of concern. Soils in the Uncompahgre Project area that primarily were derived from Mancos Shale contained the highest concentrations of total and watrer-extractable selenium. Only 5 of 128\\x11alfalfa samples had selenium concentrations that exceeded a recommended dietary limit for livestock. Selenium data for soil and alfalfa indicate that irrigation might be mobilizing and redistributing selenium in the Uncompahgre Project area. Distribution of dissolved selenium in ground water is affected by the aqueous geochemical environment of the shallow ground- water system. Selenium concentrations were as high as 1,300\\x11micrograms per liter in water from shallow wells. The highest concentrations of dissolved selenium were in water from wells completed in alluvium overlying the Mancos Shale of Cretaceous age; selenium concentrations were lower in water from wells completed in Mancos Shale residuum. Selenium in the study area could be mobilized by oxidation of reduced selenium, desorption from aquifer sediments, ion exchange, and dissolution. Infiltration of irrigation water and, perhaps nitrate, provide oxidizing conditions for mobilization of selenium from alluvium and shale residuum and for
-
Vroblesky, Don A.; Casey, Clifton C.
2007-01-01
The U.S. Geological Survey, in cooperation with the Naval Facilities Engineering Command Southeast, used newly developed sampling methods to investigate ground-water contamination by chlorobenzenes beneath a drainage ditch on the southwestern side of Installation Restoration Site 4, Naval Air Station Corpus Christi, Corpus Christi, Texas, during 2005-06. The drainage ditch, which is a potential receptor for ground-water contaminants from Installation Restoration Site 4, intermittently discharges water to Corpus Christi Bay. This report uses data from a new type of pore-water sampler developed for this investigation and other methods to examine the subsurface contamination beneath the drainage ditch. Analysis of ground water from the samplers indicated that chlorobenzenes (maximum detected concentration of 160 micrograms per liter) are present in the ground water beneath the ditch. The concentrations of dissolved oxygen in the samples (less than 0.05-0.4 milligram per liter) showed that the ground water beneath and near the ditch is anaerobic, indicating that substantial chlorobenzene biodegradation in the aquifer beneath the ditch is unlikely. Probable alternative mechanisms of chlorobenzene removal in the ground water beneath the drainage ditch include sorption onto the organic-rich sediment and contaminant depletion by cattails through uptake, sorption, and localized soil aeration.
-
Jiménez-Martínez, J.; Molinero-Huguet, J.; Candela, L.
2009-04-01
Water requirements for different crop types according to soil type and climate conditions play not only an important role in agricultural efficiency production, though also for water resources management and control of pollutants in drainage water. The key issue to attain these objectives is the irrigation efficiency. Application of computer codes for irrigation simulation constitutes a fast and inexpensive approach to study optimal agricultural management practices. To simulate daily water balance in the soil, vadose zone and aquifer the VisualBALAN V. 2.0 code was applied to an experimental area under irrigation characterized by its aridity. The test was carried out in three experimental plots for annual row crops (lettuce and melon), perennial vegetables (artichoke), and fruit trees (citrus) under common agricultural practices in open air for October 1999-September 2008. Drip irrigation was applied to crops production due to the scarcity of water resources and the need for water conservation. Water level change was monitored in the top unconfined aquifer for each experimental plot. Results of water balance modelling show a good agreement between observed and estimated water level values. For the study period, mean drainage obtained values were 343 mm, 261 mm and 205 mm for lettuce and melon, artichoke and citrus respectively. Assessment of water use efficiency was based on the IE indicator proposed by the ASCE Task Committee. For the modelled period, water use efficiency was estimated as 73, 71 and 78 % of the applied dose (irrigation + precipitation) for lettuce and melon, artichoke and citrus, respectively.
-
Experimental evaluation of drainage filters sealing in peat soils
Directory of Open Access Journals (Sweden)
Nevzorov Aleksandr Leonidovich
2014-02-01
Full Text Available The article deals with research results of the sealing of pores in drainage filters by organic particles. Permeability tests were carried out with the constant gradient 1.5. The water flow through the sample of soil was top-down.The tests were carried out with 2 types of samples: the first part of samples had layers (from up to down 300 mm peat and 2 layers of geotextile, the second part consisted of 250 mm peat, 200 mm fine sand and 2 layers of geotextile. Well decomposed peatsamples were used. Peat had the following characteristics: density is 1,05...1,06 g/cm3, specific density — 1,53...1,56 g/cm3, void ratio — 12,0...12,5. The duration of each test was 15 days. During testing the hydraulic conductivity of samples was decreased by 1.3...1.9.After completing the tests the hydraulic conductivity of sand and geotextile were measured. The content of organic matter in geotextile and fine sand was determined as well. Dry mass of organic matter in the first layer of geotextile in the first type of samples were 1,0…1,3 g per 75 cm2. The organic matter in the second layer of geotextile in the first type of samples and in the first layer of geotextile in the second type wasn’t exposed. Fine sands protected the drainage geotextile as a result of sealing of pore space of sands by organic matter.
-
Institute of Scientific and Technical Information of China (English)
无
2000-01-01
The conflict among water drainage,water supply and eco-environment protection is getting more and more serious due to the irrational drainage and exploitation of ground water resources in coal-accumulated basins of North China.Efficient solutions to the conflict are to maintain long-term dynamic balance between input and output of the ground water basins,and to try to improve resourcification of the mine water.All solutions must guarantee the eco-environment quality.This paper presents a new idea of optimum combination of water drainage,water supply and eco-environment protection so as to solve the problem of unstable mine water supply,which is caused by the changeable water drainage for the whole combination system.Both the management of hydraulic techniques and constraints in economy,society,ecology,environment,industrial structural adjustments and sustainable developments have been taken into account.Since the traditional and separate management of different departments of water drainage,water supply and eco-environment protection is broken up,these departments work together to avoid repeated geological survey and specific evaluation calculations so that large amount of national investment can be saved and precise calculation for the whole system can be obtained.In the light of the conflict of water drainage,water supply and eco-environment protection in a typical sector in Jiaozuo coal mine,a case study puts forward an optimum combination scheme,in which a maximum economic benefit objective is constrained by multiple factors.The scheme provides a very important scientific base for finding a sustainable development strategy.
-
International Nuclear Information System (INIS)
Carvalho, F.P.; Oliveira, J.M.; Malta, M.
2009-01-01
Analyses of soils, irrigation waters, agriculture products (lettuce), green pasture, and cheese were performed in samples collected in the area of the old Urgeirica uranium mine and milling facilities, Centre-North of Portugal, in order to assess the transfer of uranium series radionuclides in the environment and to man. Soils close to milling tailings display an enhancement of radioactivity. In the drainage basin of the stream Ribeira da Pantanha, receiving drainage from the tailings piles and discharges from the acid mine water treatment plant, there was enhancement of uranium series radionuclide concentrations in water and suspended matter. Agriculture products from kitchen gardens irrigated with water from the Ribeira da Pantanha show an increase of radioactivity, mainly due to uranium isotopes. Agriculture products from other kitchen gardens in this area, irrigated with groundwater, as well pasture and cheese produced locally from sheep milk did not show enhanced radionuclide concentrations. In the Urgeirica area, some soils display radionuclide concentrations higher than soils in reference areas and, in agriculture products grown there, 226 Ra was the radionuclide more concentrated by vegetables. Through ingestion of these products 226 Ra may be the main contributor to the increment of radiation dose received by local population. (author)
-
Estimation of Tile Drainage Contribution to Streamflow and Nutrient Export Loads
Schilling, K. E.; Arenas Amado, A.; Jones, C. S.; Weber, L. J.
2015-12-01
Subsurface drainage is a very common practice in the agricultural U.S. Midwest. It is typically installed in poorly drained soils in order to enhance crop yields. The presence of tile drains creates a route for agrichemicals to travel and therefore negatively impacts stream water quality. This study estimated through end-member analyses the contributions of tile drainage, groundwater, and surface runoff to streamflow at the watershed scale based on continuously monitored data. Especial attention was devoted to quantifying tile drainage impact on watershed streamflow and nutrient export loads. Data analyzed includes streamflow, rainfall, soil moisture, shallow groundwater levels, in-stream nitrate+nitrite concentrations and specific conductance. Data were collected at a HUC12 watershed located in Northeast Iowa, USA. Approximately 60% of the total watershed area is devoted to agricultural activities and forest and grassland are the other two predominant land uses. Results show that approximately 20% of total annual streamflow comes from tile drainage and during rainfall events tile drainage contribution can go up to 30%. Furthermore, for most of the analyzed rainfall events groundwater responded faster and in a more dramatic fashion than tile drainage. The State of Iowa is currently carrying out a plan to reduce nutrients in Iowa waters and the Gulf of Mexico (Iowa Nutrient Reduction Strategy). The outcome of this investigation has the potential to assist in Best Management Practice (BMP) scenario selection and therefore help the state achieve water quality goals.
-
Monitoring and remediation technologies of organochlorine pesticides in drainage water
Ismail Ahmed; Derbalah Aly; Shaheen Sabry
2015-01-01
This study was carried out to monitor the presence of organochlorine in drainage water in Kafr-El-Sheikh Governorate, Egypt. Furthermore, to evaluate the efficiencies of different remediation techniques (advanced oxidation processes [AOPs] and bioremediation) for removing the most frequently detected compound (lindane) in drainage water. The results showed the presence of several organochlorine pesticides in all sampling sites. Lindane was detected with high frequency relative to other detect...
-
Yuan Yuan; Thomas Meixner; Mark E. Fenn; Jirka Simunek
2011-01-01
Soil water dynamics and drainage are key abiotic factors controlling losses of atmospherically deposited N in Southern California. In this paper soil N leaching and trace gaseous emissions simulated by the DAYCENT biogeochemical model using its original semi‐dynamic water flow module were compared to that coupled with a finite element transient water flow...
-
Surface runoff and tile drainage transport of phosphorus in the midwestern United States.
Smith, Douglas R; King, Kevin W; Johnson, Laura; Francesconi, Wendy; Richards, Pete; Baker, Dave; Sharpley, Andrew N
2015-03-01
The midwestern United States offers some of the most productive agricultural soils in the world. Given the cool humid climate, much of the region would not be able to support agriculture without subsurface (tile) drainage because high water tables may damage crops and prevent machinery usage in fields at critical times. Although drainage is designed to remove excess soil water as quickly as possible, it can also rapidly transport agrochemicals, including phosphorus (P). This paper illustrates the potential importance of tile drainage for P transport throughout the midwestern United States. Surface runoff and tile drainage from fields in the St. Joseph River Watershed in northeastern Indiana have been monitored since 2008. Although the traditional concept of tile drainage has been that it slowly removes soil matrix flow, peak tile discharge occurred at the same time as peak surface runoff, which demonstrates a strong surface connection through macropore flow. On our research fields, 49% of soluble P and 48% of total P losses occurred via tile discharge. Edge-of-field soluble P and total P areal loads often exceeded watershed-scale areal loadings from the Maumee River, the primary source of nutrients to the western basin of Lake Erie, where algal blooms have been a pervasive problem for the last 10 yr. As farmers, researchers, and policymakers search for treatments to reduce P loading to surface waters, the present work demonstrates that treating only surface runoff may not be sufficient to reach the goal of 41% reduction in P loading for the Lake Erie Basin. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.
-
Experimental study on soluble chemical transfer to surface runoff from soil.
Tong, Juxiu; Yang, Jinzhong; Hu, Bill X; Sun, Huaiwei
2016-10-01
Prevention of chemical transfer from soil to surface runoff, under condition of irrigation and subsurface drainage, would improve surface water quality. In this paper, a series of laboratory experiments were conducted to assess the effects of various soil and hydraulic factors on chemical transfer from soil to surface runoff. The factors include maximum depth of ponding water on soil surface, initial volumetric water content of soil, depth of soil with low porosity, type or texture of soil and condition of drainage. In the experiments, two soils, sand and loam, mixed with different quantities of soluble KCl were filled in the sandboxes and prepared under different initial saturated conditions. Simulated rainfall induced surface runoff are operated in the soils, and various ponding water depths on soil surface are simulated. Flow rates and KCl concentration of surface runoff are measured during the experiments. The following conclusions are made from the study results: (1) KCl concentration in surface runoff water would decrease with the increase of the maximum depth of ponding water on soil surface; (2) KCl concentration in surface runoff water would increase with the increase of initial volumetric water content in the soil; (3) smaller depth of soil with less porosity or deeper depth of soil with larger porosity leads to less KCl transfer to surface runoff; (4) the soil with finer texture, such as loam, could keep more fertilizer in soil, which will result in more KCl concentration in surface runoff; and (5) good subsurface drainage condition will increase the infiltration and drainage rates during rainfall event and will decrease KCl concentration in surface runoff. Therefore, it is necessary to reuse drained fertile water effectively during rainfall, without polluting groundwater. These study results should be considered in agriculture management to reduce soluble chemical transfer from soil to surface runoff for reducing non-point sources pollution.
-
DEFF Research Database (Denmark)
Ernstsen, Vibeke; Olsen, Preben; Rosenbom, Annette Elisabeth
2014-01-01
of application). Furthermore, the standard climatic conditions (e.g. temperature, precipitation) as well as soil moisture and temperature to a depth of approx. 2 meter were measured. Concentrations of nitrate in the drainage and groundwater, recharge of water through the drainage system as well as depth......Since 1985, several political agreements have been adopted to protect the aquatic environment and nature in Denmark. The farmers have repeatedly been ordered to reduce the consumption of nitrogen in their agricultural production. The reductions have been imposed nation-wide regardless of e.......g. climate, soil type and local hydraulic conditions. By the end of 2013, the Danish Commission of Nature and Agriculture issued a report which recommend that for the future protection of surface nitrogen regulations should be locally adapted, and if possible, at the level of field scale. This kind...
-
Zajíček, Antonín; Fučík, Petr; Kaplická, Markéta; Liška, Marek; Maxová, Jana; Dobiáš, Jakub
2018-04-01
Dynamics of pesticides and their metabolites in drainage waters during baseflow periods and rainfall-runoff events (RREs) were studied from 2014 to 2016 at three small, tile-drained agricultural catchments in Bohemian-Moravian Highlands, Czech Republic. Drainage systems in this region are typically built in slopes with considerable proportion of drainage runoff originating outside the drained area itself. Continuous monitoring was performed by automated samplers, and the event hydrograph was separated using 18 O and 2 H isotopes and drainage water temperature. Results showed that drainage systems represent a significant source for pesticides leaching from agricultural land. Leaching of pesticide metabolites was mainly associated with baseflow and shallow interflow. Water from causal precipitation diluted their concentrations. The prerequisites for the leaching of parental compounds were a rainfall-runoff event occurring shortly after spraying, and the presence of event water in the runoff. When such situations happened consequently, pesticides concentrations in drainage water were high and the pesticide load reached several grams in a few hours. Presented results introduce new insights into the processes of pesticides movement in small, tile-drained catchments and emphasizes the need to incorporate drainage hydrology and flow-triggered sampling into monitoring programmes in larger catchments as well as in environment-conservation policy.
-
Bhadha, Jehangir H; Sexton, Anne; Lang, Timothy A; Daroub, Samira H
2017-11-07
The purpose of this study is to describe the methods used to capture flow-weighted water and suspended particulates from farm canals during drainage discharge events. Farm canals can be enriched by nutrients such as phosphorus (P) that are susceptible to transport. Phosphorus in the form of suspended particulates can significantly contribute to the overall P loads in drainage water. A settling tank experiment was conducted to capture suspended particulates during discrete drainage events. Farm canal discharge water was collected in a series of two 200 L settling tanks over the entire duration of the drainage event, so as to represent a composite subsample of the water being discharged. Imhoff settling cones are ultimately used to settle out the suspended particulates. This is achieved by siphoning water from the settling tanks via the cones. The particulates are then collected for physico-chemical analyses.
-
Uranium, thorium and radium in soil and crops
International Nuclear Information System (INIS)
Evans, S.; Eriksson, Aa.
1983-06-01
The distribution of the naturally occuring radionuclides uranium, thorium and radium in soil, plant material and drainage water was evaluated. The plant/soil concentration factors showed that very small fractions of the nuclides were available for the plants. The water/soil concentration factors were calculated; the nuclide content in drainage water generally indicated very low leaching rates. The distribution of the radionuclides was utilized with the aim to obtain reliable concentration factors which in turn could be used to calculate the transfer of nuclides within the agricultural ecosystem. Dose calculations were performed using plant/soil concentration factors based on geometric mean values. (authors)
-
Litskas, Vassilis D; Aschonitis, Vassilis G; Antonopoulos, Vassilis Z
2010-04-01
A representative agricultural area of 150 ha located in a protected ecosystem (Axios River Delta, Thermaikos Gulf-N. Aegean, Greece) was selected in order to investigate water quality parameters [pH, electrical conductivity (EC(w)), NO(3)-N, NH(4)-N, total phosphorus (TP)] in irrigation and drainage water. In the study area, the cultivated crops are mainly rice, maize, cotton, and fodder. Surface irrigation methods are applied using open channels network, and irrigation water is supplied by Axios River, which is facing pollution problems. The return flow from surface runoff and the surplus of irrigation water are collected to drainage network and disposed to Thermaikos Gulf. A 2-year study (2006-2007) was conducted in order to evaluate the effects of land use and irrigation water management on the drainage water quality. The average pH and NO(3)-N concentration was higher in the irrigation water (8.0 and 1.3 mg/L, respectively) than that in the drainage water (7.6 and 1.0 mg/L, respectively). The average EC(W), NH(4)-N, and TP concentration was higher in the drainage water (1,754 muS/cm, 90.3 microg/L, and 0.2 mg/L, respectively) than that in the irrigation water (477.1 muS/cm, 46.7 microg/L, and 0.1 mg/L, respectively). Average irrigation efficiency was estimated at 47% and 51% in 2006 and 2007 growing seasons (April-October), respectively. The loads of NO(3)-N in both seasons were higher in the irrigation water (35.1 kg/ha in 2006 and 24.9 kg/ha in 2007) than those in the drainage water (8.1 kg/ha in 2006 and 7.6 kg/ha in 2007). The load of TP was higher in the irrigation water in season 2006 (2.8 kg/ha) than that in the drainage water (1.1 kg/ha). Total phosphorus load in 2007 was equal in irrigation and drainage water (1.2 kg/ha). Wetland conditions, due to rice irrigation regime, drainage network characteristics, and the crop distribution in the study area, affect the drainage water ending in the protected ecosystem of Thermaikos Gulf.
-
Energy Technology Data Exchange (ETDEWEB)
Valdes-Abellan, J.; Jiménez-Martínez, J.; Candela, L.; Tamoh, K.
2015-07-01
Irrigated agriculture is usually performed in semi-arid regions despite scarcity of water resources. Therefore, optimal irrigation management by monitoring the soil is essential, and assessing soil hydraulic properties and water flow dynamics is presented as a first measure. For this purpose, the control of volumetric water content, θ, and pressure head, h, is required. This study adopted two types of monitoring strategies in the same experimental plot to control θ and h in the vadose zone: i) non-automatic and more time-consuming; ii) automatic connected to a datalogger. Water flux was modelled with Hydrus-1D using the data collected from both acquisition strategies independently (3820 daily values for the automatic; less than 1000 for the non-automatic). Goodness-of-fit results reported a better adjustment in case of automatic sensors. Both model outputs adequately predicted the general trend of θ and h, but with slight differences in computed annual drainage (711 mm and 774 mm). Soil hydraulic properties were inversely estimated from both data acquisition systems. Major differences were obtained in the saturated volumetric water content, θs, and the n and α van Genuchten model shape parameters. Saturated hydraulic conductivity, Ks, shown lower variability with a coefficient of variation range from 0.13 to 0.24 for the soil layers defined. Soil hydraulic properties were better assessed through automatic data acquisition as data variability was lower and accuracy was higher. (Author)
-
Directory of Open Access Journals (Sweden)
Javier Valdes-Abellan
2015-03-01
Full Text Available Abstract Irrigated agriculture is usually performed in semi-arid regions despite scarcity of water resources. Therefore, optimal irrigation management by monitoring the soil is essential, and assessing soil hydraulic properties and water flow dynamics is presented as a first measure. For this purpose, the control of volumetric water content, θ, and pressure head, h, is required. This study adopted two types of monitoring strategies in the same experimental plot to control θ and h in the vadose zone: i non-automatic and more time-consuming; ii automatic connected to a datalogger. Water flux was modelled with Hydrus-1D using the data collected from both acquisition strategies independently (3820 daily values for the automatic; less than 1000 for the non-automatic. Goodness-of-fit results reported a better adjustment in case of automatic sensors. Both model outputs adequately predicted the general trend of θ and h, but with slight differences in computed annual drainage (711 mm and 774 mm. Soil hydraulic properties were inversely estimated from both data acquisition systems. Major differences were obtained in the saturated volumetric water content, θs, and the n and α van Genuchten model shape parameters. Saturated hydraulic conductivity, Ks, shown lower variability with a coefficient of variation range from 0.13 to 0.24 for the soil layers defined. Soil hydraulic properties were better assessed through automatic data acquisition as data variability was lower and accuracy was higher.
-
International Nuclear Information System (INIS)
Robalinho, Aviani Maria Bezerra
2000-10-01
The determination of the hydraulic properties of an alluvial soil in Cajueiro reservoir has been carried out in two experimental plots of 3.5 m x 3.5 m, installed in the opposite banks of the brook in which is located the dam, (Tuparetama Country, Pernambuco). For the determination of the hydraulic conductivity as a function of the soil water volumetric content K(θ), the internal driainage method proposed by Hillel et al. (1972) has been applied. The soil-water retention curves h (θ) have been determined through the experimental data of volumetric water content and pressure obtained in field experiments. The h (θ) and K (θ) curves have been fitted to van Genuchten's closed - form equations (1980), using the Burdine's model, and Brooks and Corey's model, respectively. The volumetric water content, matric potential, and total water content estimates have been fitted to two analytical functions: one being composed by the addition of three exponentials terms the other composed and by representation the reverse of the power functions. The latter has been preferred due to its smoother representation between the fast and the slow its drainage phases. Considering the hydraulic behavior, three different layers have been identified in the soil profiles of the two experimental parcels A2 and B4 in the alluvial soil Cajueiro reservoir. The second layer of the soil profile in parcel A2 turned out the more pemeable than the other two layers. As to the soil profile in parcel B4, the first layer turned out more conductive than the other layers. However, the biggest volumetric water content variations were due to the differences found in the texture and structure of the soil profiles under study. The hydrodynamic characterization of the two soil profiles, A2 and B4, brings significant elements for the simulation of scenarios related to the soil of water transport processes. It is of particular importance the study of scenarios related to the shallow soil layers, which are
-
Effect of boundary conditions on measured water retention behavior within soils
Galindo-torres, S.; Scheuermann, A.; Pedroso, D.; Li, L.
2013-12-01
The Soil Water Characteristic Curve (SWCC) is a practical representation of the behavior of soil water by relating the suction (difference between the air and water pressures to the moisture content (water saturation). The SWCC is characterized by a hysteresis loop, which is thought to be unique in that any drainage-imbibition cycle lies within a main hysteresis loop limited by two different curves for drainage and imbibition. This 'uniqueness' is the main argument for considering the SWCC as a material-intrinsic feature that characterizes the pore structure and its interaction with fluids. Models have been developed with the SWCC as input data to describe the evolution of the water saturation and the suction within soils. One example of these models is the widely used Richard's equation [1]. In this work we present a series of numerical simulations to evaluate the 'unique' nature of the SWCC. The simulations involves the use of the Lattice Boltzmann Method (LBM) [2] within a regular soil, modelling the flow behavior of two immiscible fluids: wetting and non-wetting. The soil is packed within a cubic domain to resemble the experimental setups that are commonly used for measuring the SWCC[3]. The boundary conditions ensure that the non-wetting phase enters through one cubic face and the wetting phase enters trough the opposite phase, with no flow boundary conditions in the remaining 4 cubic faces. The SWCC known features are inspected including the presence of the common limit curves for different cycles involving varying limits for the suction. For this stage of simulations, the SWCC is indeed unique. Later, different boundary conditions are applied with the two fluids each injected from 3 opposing faces into the porous medium. The effect of this boundary condition change is a net flow direction, which is different from that in the previous case. A striking result is observed when both SWCC are compared and found to be noticeable different. Further analysis is
-
Exploring Agricultural Drainage's Influence on Wetland and ...
Artificial agricultural drainage (i.e. surface ditches or subsurface tile) is an important agricultural management tool. Artificial drainage allows for timely fieldwork and adequate root aeration, resulting in greater crop yields for farmers. This practice is widespread throughout many regions of the United States and the network of artificial drainage is especially extensive in flat, poorly-drained regions like the glaciated Midwest. While beneficial for crop yields, agricultural drains often empty into streams within the natural drainage system. The increased network connectivity may lead to greater contributing area for watersheds, altered hydrology and increased conveyance of pollutants into natural water bodies. While studies and models at broader scales have implicated artificial drainage as an important driver of hydrological shifts and eutrophication, the actual spatial extent of artificial drainage is poorly known. Consequently, metrics of wetland and watershed connectivity within agricultural regions often fail to explicitly include artificial drainage. We use recent agricultural census data, soil drainage data, and land cover data to create estimates of potential agricultural drainage across the United States. We estimate that agricultural drainage in the US is greater than 31 million hectares and is concentrated in the upper Midwest Corn Belt, covering greater than 50% of available land for 114 counties. Estimated drainage values for numerous countie
-
Physical and water properties of selected Polish heavy soils of various origins
Directory of Open Access Journals (Sweden)
Kaczmarek Zbigniew
2015-12-01
Full Text Available The paper presents the characteristics of selected physical, chemical, and water properties of four mineral arable soils characterized with heavy and very heavy texture. Soil samples from genetic horizons of black earths from areas near Kętrzyn, Gniew and Kujawy, and alluvial soils from Żuławy were used. The following properties were determined in the samples of undisturbed and disturbed structure: texture, particle density, bulk density, porosity, natural and hygroscopic moistures, maximal hygroscopic capacity, saturated hydraulic conductivity, potential of water bonding in soil, total and readily available water, total retention in the horizon of 0–50 cm, drainage porosity, content of organic carbon and total nitrogen Parent rocks of these soils were clays, silts and loams of various origin. High content of clay fraction strongly influenced the values of all the analyzed properties. All the examined soils had high content of organic carbon and total nitrogen and reaction close to neutral or alkaline. High content of mineral and organic colloids and, what follows, beneficial state of top horizons’ structure, determined – apart from heavy texture – low soil bulk density and high porosity. The investigated soils were characterized by high field water capacity and wide scopes of total and readily available water. The saturated hydraulic conductivity was low and characteristic to heavy mineral arable soils. The parameter which influenced the variability of analyzed parameters most was texture.
-
1 The Effect of Camber Bed Drainage
African Journals Online (AJOL)
User
The Effect of Camber Bed Drainage Landforms on Soil. Nutrient Distribution and Grain Yield of Maize on the Vertisols ... The Vertisols of the Accra Plains of Ghana are water logged after significant rainfall ... Excess application of 15-15-15 NPK and sulphate of ammonia fertilizers (150% .... beds, before planting and nutrient.
-
Bach, Martin; Diesner, Mirjam; Großmann, Dietlinde; Guerniche, Djamal; Hommen, Udo; Klein, Michael; Kubiak, Roland; Müller, Alexandra; Preuss, Thomas G; Priegnitz, Jan; Reichenberger, Stefan; Thomas, Kai; Trapp, Matthias
2017-05-01
In order to assess surface water exposure to active substances of plant protection products (PPPs) in the European Union (EU), the FOCUS (FOrum for the Co-ordination of pesticide fate models and their USe) surface water workgroup introduced four run-off and six drainage scenarios for Step 3 of the tiered FOCUSsw approach. These scenarios may not necessarily represent realistic worst-case situations for the different Member States of the EU. Hence, the suitability of the scenarios for risk assessment in the national authorisation procedures is not known. Using Germany as an example, the paper illustrates how national soil-climate scenarios can be developed to model entries of active substances into surface waters from run-off and erosion (using the model PRZM) and from drainage (using the model MACRO). In the authorisation procedure for PPPs on Member State level, such soil-climate scenarios can be used to determine exposure endpoints with a defined overall percentile. The approach allows the development of national specific soil-climate scenarios and to calculate percentile-based exposure endpoints. The scenarios have been integrated into a software tool analogous to FOCUS-SWASH which can be used in the future to assess surface water exposure in authorisation procedures of PPPs in Germany. © 2017 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. © 2017 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
-
Effects of a layer of vegetative ash layer on wettable and water repellent soil hydrology
Bodí, Merche B.; Doerr, Stefan H.; Cerdà, Artemi; Mataix-Solera, Jorge
2010-05-01
Following a wildfire, a layer of vegetative ash often covers the ground until it is dissolved or redistributed by wind and water erosion. Much of the existing literature suggests that the ash layer temporally reduces infiltration by clogging soil pores or by forming a surface crust (Mallik et al., 1984; Onda et al., 2008). However, an increasing number of field-based studies have found that, at least in the short term, ash increases infiltration by storing rainfall and protecting the underlying soil from sealing (Cerdà and Doerr, 2008; Woods and Balfour, 2008). On the other hand, after a fire the soil may have produced, enhanced or reduced its water repellency (Doerr et al., 2000). Very few studies have been taken into account the interaction of the ash and the repellent soil. The layer of ash may have similar role as a litter layer in delaying runoff and reducing erosion by storing water. In order to examine this interaction, it was been made a series of experiments using a laboratory rainfall simulation. It has been assessed the effects of an ash layer i) on a wettable and water repellent soil (WDPT > 7200s), ii) with different ash thicknesses (bare soil and 5 mm, 15 mm and 30 mm of ash), iii) preceding and following the first rain after a fire when the ground is still wetted and after being partially dried. Three replicates were done, being a total of 40 simulations. The ash used was collected from a Wildfire in Teruel (Spain) during summer of 2009. The simulations were conducted in metal boxes of 30x30 cm and filled with 3 cm of soil. The slope of the box was set at 10° (17%) and the intensity applied was 78-84 mm h-1during 40 minutes. The splash detachment was determined also using four splash cups. Overland flow and subsurface drainage was collected at 1-minute intervals and the former stored every 5 min to allow determination of sediment concentrations, yield and erosion rates. Each sample was examined at the end in terms of water repellency, infiltration
-
Evaluation of the sustainability of road drainage systems
García-Diez, Iván; Palencia, Covadonga; Fernández Raga, María
2017-04-01
Water is the most erosive agent that exists on the linear structures, because they are constantly subjected to outdoor condition like irregular infiltration, frosts and different rain intensities. Another variables that highly influence in the entire lifetime of a natural drainage system are the spatial and temporal variability of the rainfall, the soil, the vegetation cover and the design. All this factors are affecting the vulnerability of the clearings and embankments, by wearing away the weakest materials which surround the roads or train rails, producing erosion and very bumpy surfaces. The result is that the original pattern, developped to disminished the lost of soil, is not properly working and it cannot eliminate water, with the consequence destruction of the linear structure after several rainfall periods, and the accumulation of material down slope. The propose of this research focuses on analysing the drainage systems used in spanish roads and railways lines. For this purpose, a revision of the literature has been done, and the main drainage solutions have been recovered, carrying out an evaluation of them from an environmental point of view. This procedure has been requested by several authors in the past (Nwa, E.U. & Twocock, J.G., 1969; Goulter, I.C., 1992), together with the need of designing a more sustainable drainage system. The final objective of this complete revision is to compare objetively the designs to valuate them in order to develop a new drainage patter which minimize the erosion, increasing the durability and effectiveness of the drainage system. For this purpose, it is neccesary to assure that all the systems will be compare under similar parameters of flow rate, vegetation, substrate, lenght, slope and total section. Only the channels pattern and water distribution will change. The analysis has been done following Liu, H. & Zhu, X.B., (2012), who pointed out that the main parameters to take into account to select a road drainage
-
Rakotonimaro, Tsiverihasina V; Neculita, Carmen Mihaela; Bussière, Bruno; Benzaazoua, Mostafa; Zagury, Gérald J
2017-01-01
The treatment of mine drainage-impacted waters generates considerable amounts of sludge, which raises several concerns, such as storage and disposal, stability, and potential social and environmental impacts. To alleviate the storage and management costs, as well as to give the mine sludge a second life, recovery and reuse have recently become interesting options. In this review, different recovery and reuse options of sludge originating from active and passive treatment of mine drainage are identified and thoroughly discussed, based on available laboratory and field studies. The most valuable products presently recovered from the mine sludge are the iron oxy-hydroxides (ochre). Other by-products include metals, elemental sulfur, and calcium carbonate. Mine sludge reuse includes the removal of contaminants, such as As, P, dye, and rare earth elements. Mine sludge can also be reused as stabilizer for contaminated soil, as fertilizer in agriculture/horticulture, as substitute material in construction, as cover over tailings for acid mine drainage prevention and control, as material to sequester carbon dioxide, and in cement and pigment industries. The review also stresses out some of the current challenges and research needs. Finally, in order to move forward, studies are needed to better estimate the contribution of sludge recovery/reuse to the overall costs of mine water treatment.
-
Donald D. Hook
1969-01-01
Swamp chestnut oak (Quercus michauxii Nutt.) seedlings were grown for 2 years in five soil types in drained and undrained pots. First-year height growth was related to soil type and pot drainage, but second-year height growth was related only to soil type. Results suggest that swamp chestnut oak is site-sensitive. But slow growth, a maximum of 2...
-
Wang, Huanyuan; Han, Jichang; Tong, Wei; Cheng, Jie; Zhang, Haiou
2017-06-01
Maize was grown on compound soils constituted from mixtures of soft rock and sand at different ratios, and water use efficiency (WUE), nitrogen use efficiency (NUE) and fertilizer nitrogen use efficiency (FNUE) were quantified. The data were used to assist in designing strategies for optimizing water and nitrogen management practices for maize on the substrates used. Maize was sown in composite soil prepared at three ratios of soft rock and sand (1:1, 1:2 and 1:5 v/v) in Mu Us Sandy Land, Yuyang district, Yulin city, China. Yields, amount of drainage, nitrogen (N) leaching, WUE and NUE were calculated. Then a water and nitrogen management model (WNMM) was calibrated and validated. No significant difference in evapotranspiration of maize was found among compound soils with soft rock/sand ratios of 1:1, 1:2 and 1:5, while water drainage increased significantly with increasing soft rock/sand ratio. WUE increased to 1.30 kg m -3 in compound soil with 1:2 soft rock/sand ratio. Nitrogen leaching and ammonia volatilization were the main reason for nitrogen loss, and N reduction mainly relied on crop uptake. NUE and FNUE could reach 33.1 and 24.9 kg kg -1 N respectively. Water drainage and nitrogen leaching occurred mostly during heavy rainfall or irrigation. Through a scenario analysis of different rainfall types, water and fertilizer management systems were formulated each year. This study shows that soft rock plays a key role in improving the WUE, NUE and FNUE of maize. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.
-
The Effect of Camber Bed Drainage Landforms on Soil Nutrient ...
African Journals Online (AJOL)
The Vertisols of the Accra Plains of Ghana are water logged after significant rainfall due to the low-lying topography (0.1-1 %). Camber bed (Cb) drainage landforms have been developed at the Agricultural Research Centre, Kpong, for draining off excess water. Field experiments were conducted to verify if maize growth and ...
-
Water, solute and heat transport in the soil: the Australian connection
Knight, John
2016-04-01
The interest of Peter Raats in water, solute and heat transport in the soil has led to scientific and/or personal interactions with several Australian scientists such as John Philip, David Smiles, Greg Davis and John Knight. Along with John Philip and Robin Wooding, Peter was an early user of the Gardner (1958) linearised model of soil water flow, which brought him into competition with John Philip. I will discuss some of Peter's solutions relevant to infiltration from line and point sources, cavities and basins. A visit to Canberra, Australia in the early 1980s led to joint work on soil water flow, and on combined water and solute movement with David Smiles and others. In 1983 Peter was on the PhD committee for Greg Davis at the University of Wollongong, and some of the methods in his thesis 'Mathematical modelling of rate-limiting mechanisms of pyritic oxidation in overburden dumps' were later used by Peter's student Sjoerd van der Zee. David Smiles and Peter wrote a survey article 'Hydrology of swelling clay soils' in 2005. In the last decade Peter has been investigating the history of groundwater and vadose zone hydrology, and recently he and I have been bringing to light the largely forgotten work of Lewis Fry Richardson on finite difference solution of the heat equation, drainage theory, soil physics, and the soil-plant-atmosphere continuum.
-
DETERMINATION OF EFFICIENCY OF THE CIRCUMFERENTIAL DRAINAGE SYSTEM
Directory of Open Access Journals (Sweden)
Maciej Kroll
2015-11-01
Full Text Available One of the potential alternatives to improve the stability coefficient for an embankment structure is to flatten the filtration curve. As a result, we obtain lower body forces triggering the potential landslide and more advantageous soil strength parameters, which counteract landslide movements. In the case of waste dumps lowering the phreatic surface of waters is achieved thanks to the construction of auxiliary drainage systems, meeting the guidelines for their safe operation. The aim of this paper is to indicate a method facilitating the determination of the actual position of the phreatic surface within the deposited sediments and the assessment of efficiency of the circumferential drainage system in the waste dump. It was decided in this study to apply cone penetration test CPTU. The CPTU made it possible to measure dissipation of excess water pressure in pores identifying drainage conditions, which were compared with the results of piezometric measurements. The results of these tests made it possible to monitor changes in the position of the depression curve of supernatant waters in dams and to determine the efficiency of the circumferential drainage system.
-
The Metal And Sulphate Removal From Mine Drainage Waters By Biological-Chemical Ways
Directory of Open Access Journals (Sweden)
Jenčárová Jana
2015-06-01
Full Text Available Mine drainage waters are often characterized by high concentrations of sulphates and metals as a consequence of the mining industry of sulphide minerals. The aims of this work are to prove some biological-chemical processes utilization for the mine drainage water treatment. The studied principles of contamination elimination from these waters include sulphate reduction and metal bioprecipitation by the application of sulphate-reducing bacteria (SRB. Other studied process was metal sorption by prepared biogenic sorbent. Mine drainage waters from Slovak localities Banská Štiavnica and Smolník were used to the pollution removal examination. In Banská Štiavnica water, sulphates decreased below the legislative limit. The elimination of zinc by sorption experiments achieved 84 % and 65 %, respectively.
-
Evaluating the Performance of a Surface Barrier on Reducing Soil-Water Flow
Energy Technology Data Exchange (ETDEWEB)
Zhang, Z. F.; Strickland, Christopher E.; Field, Jim G.; Parker, Danny L.; Clayton, Ray E.
2012-08-31
One of the most common effective techniques for contaminant remediation in the vadose zone is to use a surface barrier to reduce or eliminate soil-water flow to reduce the contaminant flux to the underlying groundwater. Confirming the reduction of the soil-water flux rate is challenging because of the difficulty of determining the very low soil-water flux beneath the barrier. We propose a hydraulic-conductivity factor, fK, as a conservative indicator for quantifying the reduction of soil-water flow. The factor can be calculated using the measured soil-water content or pressure but does not require the knowledge of the saturated hydraulic conductivity or the hydraulic gradient. The formulas were tested by comparing with changes in hydraulic conductivity, K, from a drainage experiment. The pressure-based formula was further applied to evaluate the performance of the interim surface barrier at T Tank Farm on Hanford Site. Three years after barrier emplacement, the hydraulic conductivity decreased by a factor between 3.8 and 13.0 at the 1-, 2- and 5-m depths. The difference between the conductivity-reduction factor and the flux-rate-reduction factor, fq, was quantified with a numerical simulation. With the calculated fK, the numerically determined fK/fq ratio, and the assumed pre-barrier soil-water flux rate of 100 mm yr-1, the estimated soil-water flux rate 3 years after barrier emplacement was no more than 8.5 mm yr-1 at or above the 5-m depth.
-
The foam drainage equation for drainage dynamics in unsaturated porous media
Lehmann, P.; Hoogland, F.; Assouline, S.; Or, D.
2017-07-01
Similarity in liquid-phase configuration and drainage dynamics of wet foam and gravity drainage from unsaturated porous media expands modeling capabilities for capillary flows and supplements the standard Richards equation representation. The governing equation for draining foam (or a soil variant termed the soil foam drainage equation—SFDE) obviates the need for macroscopic unsaturated hydraulic conductivity function by an explicit account of diminishing flow pathway sizes as the medium gradually drains. The study provides new and simple analytical expressions for drainage rates and volumes from unsaturated porous media subjected to different boundary conditions. Two novel analytical solutions for saturation profile evolution were derived and tested in good agreement with a numerical solution of the SFDE. The study and the proposed solutions rectify the original formulation of foam drainage dynamics of Or and Assouline (2013). The new framework broadens the scope of methods available for quantifying unsaturated flow in porous media, where the intrinsic conductivity and geometrical representation of capillary drainage could improve understanding of colloid and pathogen transport. The explicit geometrical interpretation of flow pathways underlying the hydraulic functions used by the Richards equation offers new insights that benefit both approaches.
-
Tropical organic soils ecosystems in relation to regional water resources in southeast Asia
Energy Technology Data Exchange (ETDEWEB)
Armentano, T. V.
1982-01-01
Tropical organic soils have functioned as natural sinks for carbon, nitrogen, slfur and other nutrients for the past 4000 years or more. Topographic evolution in peat swamp forests towards greater oligotrophy has concentrated storage of the limited nutrient stock in surface soils and biota. Tropical peat systems thus share common ecosystem characteristics with northern peat bogs and certain tropical oligotrophic forests. Organic matter accumulation and high cation-exchange-capacity limit nutrient exports from undisturbed organic soils, although nutrient retention declines with increasing eutrophy and wetland productivity. Peat swamps are subject to irreversible degradation if severely altered because disturbance of vegetation, surface peats and detritus can disrupt nuttrient cycles and reduce forest recovery capacity. Drainage also greatly increases exports of nitrogen, phosphorus and other nutrients and leads to downstream eutrophication and water quality degradation. Regional planning for clean water supplies must recognize the benefits provided by natural peatlands in balancing water supplies and regulating water chemistry.
-
Yang, Yanmin; Liu, De Li; Anwar, Muhuddin Rajin; O'Leary, Garry; Macadam, Ian; Yang, Yonghui
2016-02-01
Wheat production is expected to be affected by climate change through changing components of the crop water balance such as rainfall, evapotranspiration (ET), runoff and drainage. We used the Agricultural Production Systems Simulator (APSIM)-wheat model to simulate the potential impact of climate change on field water balance, ET and water use efficiency (WUE) under the SRES A2 emissions scenario. We ran APSIM with daily climate data statistically downscaled from 18 Global Circulation Models (GCMs). Twelve soil types of varying plant available water holding capacity (PAWC) at six sites across semi-arid southeastern Australia were considered. Biases in the GCM-simulated climate data were bias-corrected against observations for the 1961-1999 baseline period. However, biases in the APSIM output data relative to APSIM simulations forced with climate observations remained. A secondary bias correction was therefore performed on the APSIM outputs. Bias-corrected APSIM outputs for a future period (2021-2040) were compared with APSIM outputs generated using observations for the baseline period to obtain future changes. The results show that effective rainfall was decreased over all sites due to decreased growing season rainfall. ET was decreased through reduced soil evaporation and crop transpiration. There were no significant changes in runoff at any site. The variation in deep drainage between sites was much greater than for runoff, ranging from less than a few millimetres at the drier sites to over 100 mm at the wetter. However, in general, the averaged drainage over different soil types were not significantly different between the baseline (1961-1999) and future period of 2021-2040 ( P > 0.05). For the wetter sites, the variations in the future changes in drainage and runoff between the 18 GCMs were larger than those of the drier sites. At the dry sites, the variation in drainage decreased as PAWC increased. Overall, water use efficiency based on transpiration (WUE
-
International Nuclear Information System (INIS)
Preko, Kwasi; Scheuermann, Alexander; Wilhelm, Helmut
2009-01-01
Water infiltration through a dike model under controlled flooding and drainage conditions was investigated using the gravimetric soil water sampling technique and electromagnetic techniques, in particular ground penetrating radar (GPR) applied in different forms, time domain reflectometry with intelligent microelements (TRIME-TDR) and spatial-time domain reflectometry (S-TDR). The experiments were conducted on the model in two phases. In the first phase, the model was flooded with varying water levels between 0 and 1.25 m above the waterproof base of the model. In the second phase, the characteristics of the temporal water content changes were investigated over a period of 65 days as the flood water drained off from the 1.25 m level. The dike model was constructed with soil of the texture class loamy sand. The aim of the experiment was to investigate whether GPR-based invasive and non-invasive methods were able to quantitatively observe and correctly monitor temporal changes in the volumetric water content (VWC) within embankment dams. The VWC values from the various techniques corresponded very well, especially with low VWC values. A comparison with the VWC of gravimetric soil water sampling showed a satisfactory reproducibility. Characteristic discrepancies were recorded with higher values of the VWC. Under saturated conditions only the invasive methods were able to produce reasonable values of the VWC. After the release of the highest flood level, the drainage phase could be characterized by two invasive methods based on the TDR and GPR techniques
-
Sustainable use of Brackish water for crop production
International Nuclear Information System (INIS)
Chaudhry, M.R.; Iqbal, M.; Subhani, K.M.
2005-01-01
The good quality surface-water is not sufficient to meet the crop water requirement for potential crop production. To augment the inadequate supplies of good quality water the only alternative is the use of poor quality , ground water. To explore sustainable use of brackish water a study was conducted in Fordwah Eastern Sadiqia South, Bahawalnagar, Punjab during the year 1998-99 to 2000-2001 with the objective to evaluate the impact of different irrigation treatments on physical and chemical properties of soil and crops yield. The experiment was conducted on farmer's field with his collaboration. The initial soil pH was about 8.0 while ECe and SAR ranged between 2.0 to 4.1 dS m/sup -/1 and 7.1 to 15.1 (mmol/sub c/ L/sup -1/)1/2, respectively with sandy loam texture. The brackish water used for irrigation had ECiw, SAR and RSC between 5.6 to 6.7 dS m/sup -/1, 15.1 to 16.4 (mmolc L/sup -1/sup 1/2/ and 1.52 to 1.64 (mmol/sub c/ L/sup -1/.The crops tested were wheat during Rabi and cotton during Kharif season. The treatments tested were: irrigation with canal water (T/sub 1/), canal water during Rabi and drainage water during Kharif (T/sub 2/), drainage water for two years and canal water for one season(T/sub 3/); and drainage water for three years + application of gypsum at the rate of 25% of CWR and thereafter canal water for one season(T 4). Fertilizers were applied at the rate of 120-60-50 N, P/sub 2/O/sub 5/ and K20 kg ha/sup -1/, respectively in the form of urea, diammonium phosphate and sulfate of potash. Crops irrigated with drainage water visualized yield reduction depending upon the share of drainage water in the irrigation delta. Application of gypsum provided reasonable check against salinity build-up with brackish water irrigation besides a nominal boost of 3 and 5% in yield of wheat and cotton, respectively over comparable treatment of year-round brackish water irrigation lacking gypsum application. Drainage water in alternate arrangement of seasonal
-
Percolation theory and its application for interpretation of soil water retention curves
International Nuclear Information System (INIS)
Kodesova, R.
2004-01-01
The soil porous system has traditionally been deduced from the soil-water retention curve with the assumption of homogeneity and free accessibility of pores, defined as capillary tubes, from the sink/source of water. But real soil fabric is mostly characterized by aggregates. In this case, the soil porous system cannot be modeled as a homogeneous one. To examine the differences between homogeneous and heterogeneous soil porous systems, we studied two types of soils: sandy soil and coarse sandy soil. We applied image processing filters and the ARC/INFO Grid module to analyze pore sizes in both soils from their electron microscope images taken at two different magnifications. We used the resulting pore-size distribution data to generate 3-D porous media consisting of pores and throats. The homogeneous pore structure was created as a mono-modal pore-throat network with one pore-size distribution. The heterogeneous pore structure was designed as a bi-modal pore-throat network with two pore-size distributions, where the pore sizes were hierarchically arranged in the nodes of the network. We applied the percolation model to simulate water and air displacement in these networks. The distribution of water in the nodes of the networks was studied increasing/decreasing steps of pressure head and the drainage and wetting branches of the retention curves were evaluated. The soil-water retention curves modeled for the mono-modal and bi-modal porous systems had different characters. The simulated shape of the retention curve in the mono-modal case was close to the step-like form of a retention curve characteristic of unstructured soil. The shape of the simulated retention curve in the bi-modal case was smoother, more gradual, and closer to the shape of the retention curve of a real, structured soil. (author)
-
Frey, Steven K; Topp, Ed; Ball, Bonnie R; Edwards, Mark; Gottschall, Natalie; Sunohara, Mark; Zoski, Erin; Lapen, David R
2013-01-01
This study investigated the potential for controlled tile drainage (CD) to reduce bacteria and nutrient loading to surface water and groundwater from fall-season liquid manure application (LMA) on four macroporous clay loam plots, of which two had CD and two had free-draining (FD) tiles. Rhodamine WT (RWT) was mixed into the manure and monitored in the tile water and groundwater following LMA. Tile water and groundwater quality were influenced by drainage management. Following LMA on the FD plots, RWT, nutrients, and bacteria moved rapidly via tiles to surface water; at the CD plots, tiles did not flow until the first post-LMA rainfall, so the immediate risk of LMA-induced contamination of surface water was abated. During the 36-d monitoring period, flow-weighted average specific conductance, redox potential, and turbidity, as well as total Kjeldahl N (TKN), total P (TP), NH-N, reactive P, and RWT concentrations, were higher in the CD tile effluent; however, because of lower tile discharge from the CD plots, there was no significant ( ≤ 0.05) difference in surface water nutrient and RWT loading between the CD and FD plots when all tiles were flowing. The TKN, TP, and RWT concentrations in groundwater also tended to be higher at the CD plots. Bacteria behaved differently than nutrients and RWT, with no significant difference in total coliform, , fecal coliform, fecal streptococcus, and concentrations between the CD and FD tile effluent; however, for all but , hourly loading was higher from the FD plots. Results indicate that CD has potential for mitigating bacteria movement to surface water. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.
-
International Nuclear Information System (INIS)
Nielsen, D.R.; Cassel, D.K.
1984-01-01
The use of radiation and tracer techniques in investigations into soil water management in agriculture, hydrology etc. is described. These techniques include 1) neutron moisture gauges to monitor soil water content and soil water properties, 2) gamma radiation attenuation for measuring the total density of soil and soil water content, 3) beta radiation attenuation for measuring changes in the water status of crop plants and 4) radioactive and stable tracers for identifying pathways, reactions and retention times of the constituents in soils and groundwater aquifers. The number and spacing of soil observations that should be taken to represent the management unit are also considered. (U.K.)
-
Wu, Haibing
2018-01-01
Watershed prioritization with the objective of identifying critical areas to undertake soil and water conservation measures was conducted in the upper Han River basin, the water source area of approximately 95,000 km 2 for the middle route of China's South-to-North Water Transfer Project. Based on the estimated soil erosion intensity in uplands and clustering analysis of measured nutrient concentrations in rivers, the basin was grouped into very-high-, high-, moderate-, and low-priority regions for water and soil conservation, respectively. The results indicated that soil erosion was primarily controlled by topography, and nutrients in rivers were associated with land use and land cover in uplands. Also, there was large spatial disparity between soil erosion intensity in the uplands and nutrient concentrations in the rivers across the basin. Analysis was then performed to prioritize the basin by the integration of the soil erosion intensity and water quality on a GIS platform in order to identify critical areas for water and soil conservation in the basin. The identified high-priority regions which occupy 5.74% of the drainage areas need immediate attention for soil and water conservation treatments, of which 5.28% is critical for soil erosion prevention and 0.46% for water conservation. Understandings of the basin environment and pollutant loading with spatial explicit are critical to the soil and water resource conservation for the interbasin water transfer project.
-
Long-Term Drainage from the Riprap Side Slope of a Surface Barrier
Energy Technology Data Exchange (ETDEWEB)
Zhang, Zhuanfang
2017-07-01
Surface barriers designed to isolate underground nuclear waste in place are expected to function for at least 1000 years. To achieve this long design life, such barriers need to be protected with side slopes against wind- and water-induced erosion and damage by natural or human activities. However, the side slopes are usually constructed with materials coarser than the barrier. Their hydrological characteristics must be understood so that any drainage from them is considered in the barrier design and will not compromise the barrier function. The Prototype Hanford Barrier, an evapotranspiration-capillary (ETC) barrier, was constructed in 1994 at the Hanford Site in southeastern Washington state, with a gravel side slope and a riprap side slope. The soil water content in the gravel side slope and drainage from both side slopes have been monitored since the completion of construction. The monitoring results show that under natural precipitation the annual drainage rates from the two types of side slopes were very similar and about 5 times the typical recharge from local soil with natural vegetation and 40 times the barrier design criterion. The higher recharge from the side slopes results in some of the drainage migrating laterally to the region beneath the ETC barrier. This edge effect of the enhanced drainage was evaluated for a period of 1000 years by numerical simulation. The edge effect was quantified by the amount of water across the barrier edges and the affecting distance of the barrier edges. These results indicate that design features can be adjusted to reduce the edge effect when necessary.
-
Isotopic study of water evaporation in a clayey soil, experimentation and modelling
International Nuclear Information System (INIS)
Mathieu, R.; Bariac, T.
1995-01-01
The isotopic theory of soil water evaporation in steady-state was applied to the quantification of shallow water table discharge rates in arid and semi-arid climates. This approach is limited by the time needed by the soil to reach the steady state after the last significant rain event. The 1D numerical model ''Moise'', proposed here, was developed for the simulation of the vertical profiles of water and stable isotope contents in a drying soil for any initial profile and atmospheric condition. Six non-perturbed soil columns of 1.1 m length were taken from Barogo, Burkina Faso and were saturated in the laboratory by infiltration and free drainage of pounding water and then allowed to evaporate freely. The columns were then sequentially sampled after 11, 42, 92, 162 and 253 days of drying for 18 O and 2 H isotopic analyses. 18 O profiles show an exponential shape during the first drying stage with a maximum isotopic enrichment at the surface. During the second drying stage, the penetration of very depleted atmospheric vapor tends to lower the isotopic content at the surface. The water and isotopic content were simulated with the Moise model. The model satisfactory reproduces the hydrodynamic evolution and the qualitative evolution of soil water isotopic content, but it largely overestimates the overall enrichment. It is thus plausible that a fraction of the soil water may keep its own isotopic composition with restricted exchanges with the surrounding mobile water and vapor, while a mobile phase can be affected by the isotopic enrichment. (J.S.). 27 refs., 6 figs., 3 tabs
-
Golomeova, Mirjana; Zendelska, Afrodita; Krstev, Boris; Golomeov, Blagoj; Krstev, Aleksandar
2012-01-01
Water flowing from underground and surface mines and contains high concentrations of dissolved metals is called mine drainage. Mine drainage can be categorized into several basic types by their alkalinity or acidity. Sulfide rich and carbonate poor materials are expected to produce acidic drainage, and alkaline rich materials, even with significant sulfide concentrations, often produce net alkaline water. Mine drainages are dangerous because pollutants may decompose in the environment. In...
-
Uncertainty Assessment in Urban Storm Water Drainage Modelling
DEFF Research Database (Denmark)
Thorndahl, Søren
The object of this paper is to make an overall description of the author's PhD study, concerning uncertainties in numerical urban storm water drainage models. Initially an uncertainty localization and assessment of model inputs and parameters as well as uncertainties caused by different model...
-
Water extraction and implications on soil moisture sensor placement in the root zone of banana
Directory of Open Access Journals (Sweden)
Alisson Jadavi Pereira da Silva
Full Text Available ABSTRACT: The knowledge on spatial and temporal variations of soil water storage in the root zone of crops is essential to guide the studies to determine soil water balance, verify the effective zone of water extraction in the soil and indicate the correct region for the management of water, fertilizers and pesticides. The objectives of this study were: (i to indicate the zones of highest root activity for banana in different development stages; (ii to determine, inside the zone of highest root activity, the adequate position for the installation of soil moisture sensors. A 5.0 m3 drainage lysimeter was installed in the center of an experimental area of 320 m2. Water extraction was quantified inside the lysimeter using a 72 TDR probe. The concept of time stability was applied to indicate the position for sensor installation within the limits of effective water extraction. There are two patterns of water extraction distribution during the development of banana and the point of installation of sensors for irrigation management inside the zone of highest root activity is not constant along the crop development.
-
Pineda, M C; Viloria, J; Martínez-Casasnovas, J A; Valera, A; Lobo, D; Timm, L C; Pires, L F; Gabriels, D
2018-02-22
Soil water content is a key property in the study of water available for plants, infiltration, drainage, hydraulic conductivity, irrigation, plant water stress and solute movement. However, its measurement consumes time and, in the case of stony soils, the presence of stones difficult to determinate the water content. An alternative is the use of pedotransfer functions (PTFs), as models to predict these properties from readily available data. The present work shows a comparison of different widely used PTFs to estimate water content at-33 kPa (WR -33kPa ) in high stoniness soils. The work was carried out in the Caramacate River, an area of high interest because the frequent landslides worsen the quality of drinking water. The performance of all evaluated PTFs was compared with a PTF generated for the study area. Results showed that the Urach's PTF presented the best performance in relation to the others and could be used to estimate WR -33kPa in soils of Caramacate River basin. The calculated PTFs had a R 2 of 0.65. This was slightly higher than the R 2 of the Urach's PTF. The inclusion of the rock fragment volume could have the better results. The weak performance of the other PTFs could be related to the fact that the mountain soils of the basin are rich in 2:1 clay and high stoniness, which were not used as independent variables for PTFs to estimate the WR -33kPa .
-
Filion, Rébecca; Bernier, Monique; Paniconi, Claudio; Chokmani, Karem; Melis, Massimo; Soddu, Antonino; Talazac, Manon; Lafortune, Francois-Xavier
2016-02-01
The aim of this study is to investigate the potential of radar (ENVISAT ASAR and RADARSAT-2) and LANDSAT data to generate reliable soil moisture maps to support water management and agricultural practice in Mediterranean regions, particularly during dry seasons. The study is based on extensive field surveys conducted from 2005 to 2009 in the Campidano plain of Sardinia, Italy. A total of 12 small bare soil fields were sampled for moisture, surface roughness, and texture values. From field scale analysis with ENVISAT ASAR (C-band, VV polarized, descending mode, incidence angle from 15.0° to 31.4°), an empirical model for estimating bare soil moisture was established, with a coefficient of determination (R(2)) of 0.85. LANDSAT TM5 images were also used for soil moisture estimation using the TVX slope (temperature/vegetation index), and in this case the best linear relationship had an R(2) of 0.81. A cross-validation on the two empirical models demonstrated the potential of C-band SAR data for estimation of surface moisture, with and R(2) of 0.76 (bias +0.3% and RMSE 7%) for ENVISAT ASAR and 0.54 (bias +1.3% and RMSE 5%) for LANDSAT TM5. The two models developed at plot level were then applied over the Campidano plain and assessed via multitemporal and spatial analyses, in the latter case against soil permeability data from a pedological map of Sardinia. Encouraging estimated soil moisture (ESM) maps were obtained for the SAR-based model, whereas the LANDSAT-based model would require a better field data set for validation, including ground data collected on vegetated fields. ESM maps showed sensitivity to soil drainage qualities or drainage potential, which could be useful in irrigation management and other agricultural applications. Copyright © 2015 Elsevier B.V. All rights reserved.
-
[Monitoring of water and salt transport in silt and sandy soil during the leaching process].
Fu, Teng-Fei; Jia, Yong-Gang; Guo, Lei; Liu, Xiao-Lei
2012-11-01
Water and salt transport in soil and its mechanism is the key point of the saline soil research. The dynamic rule of water and transport in soil during the leaching process is the theoretical basis of formation, flush, drainage and improvement of saline soil. In this study, a vertical infiltration experiment was conducted to monitor the variation in the resistivity of silt and sandy soil during the leaching process by the self-designed automatic monitoring device. The experimental results showed that the peaks in the resistivity of the two soils went down and faded away in the course of leaching. It took about 30 minutes for sandy soil to reach the water-salt balance, whereas the silt took about 70 minutes. With the increasing leaching times, the desalination depth remained basically the same, being 35 cm for sandy soil and 10 cm for the silt from the top to bottom of soil column. Therefore, 3 and 7 leaching processes were required respectively for the complete desalination of the soil column. The temporal and spatial resolution of this monitoring device can be adjusted according to the practical demand. This device can not only achieve the remote, in situ and dynamic monitoring data of water and salt transport, but also provide an effective method in monitoring, assessment and early warning of salinization.
-
Management of poor quality irrigation water
International Nuclear Information System (INIS)
Change, M.H.; Leghari, A.M.; Sipio, Q.A.
2000-01-01
The effect of poor quality drainage effluent on moderately saline sodic, medium textured soil at different growth stages of wheat and cotton is reported. The irrigation treatments were: I) All canal irrigations, II) one irrigation of 75 mm with saline drainage effluent (EC = 3 dS m1) after four weeks sowing of the crop, III) one irrigation of 75 mm with saline drainage effluent after seven weeks sowing of the crop, and IV) one irrigation of 75 mm with saline drainage effluent after ten weeks sowing of the crop. The treatments receiving saline water gave significant decrease in crop yields as compared to canal irrigation treatment. The higher yield of wheat and seed cotton was recorded T1 followed by T2, T3 and T4. The trend of produce was T1< T2< T3< T4 respectively. Electrical conductivity of the soil (Ece) in T1 was decreased and in other three treatments was increased, whereas, pH decreased in T1 and T2. The SAR of soil decreased in all the treatments as compared with initial values. Treatment receiving an irrigation with saline water after four weeks of sowing (T2) was better in reducing soil salinity as compared to treatments receiving such water after 7 or 10 weeks os sowing. Poor quality water (EC = 3 d Sm/sup -1/) can be managed for irrigation after four weeks of swing of crops provided certain soil and water management practices like good seed bed preparation and proper drainage measures are adopted. (author)
-
Integrating lysimeter drainage and eddy covariance flux measurements in a groundwater recharge model
DEFF Research Database (Denmark)
Vasquez, Vicente; Thomsen, Anton Gårde; Iversen, Bo Vangsø
2015-01-01
Field scale water balance is difficult to characterize because controls exerted by soils and vegetation are mostly inferred from local scale measurements with relatively small support volumes. Eddy covariance flux and lysimeters have been used to infer and evaluate field scale water balances...... because they have larger footprint areas than local soil moisture measurements.. This study quantifies heterogeneity of soil deep drainage (D) in four 12.5 m2 repacked lysimeters, compares evapotranspiration from eddy covariance (ETEC) and mass balance residuals of lysimeters (ETwbLys), and models D...
-
Directory of Open Access Journals (Sweden)
B. Glina
2016-10-01
Full Text Available One important need in the context of peatland restoration is to gain knowledge of soil organic matter quality and current soil-forming process in degraded peatlands. The aim of this study was to evaluate the impact of long-term drainage on soil transformation processes. In autumn 2012, soil survey and sampling was carried out on five shallow peatlands in the Central Sudeten Mountains (Poland which had been drained for forestry use in the late 1800s or early 1900s. Four organic soils (Histosols and one organo-mineral soil (Histic Gleysol were studied. The surface soil horizons were mainly transformed due to long-term forestry drainage. Increased aeration of these layers had enhanced their content of labile forms of carbon and they were undergoing secondary transformation. Soil transformation was more advanced in fen peatlands than in transitional mire or raised bogs. Only the fens exhibited characteristic evidence of the moorsh-forming process. Further drying of these soils will negatively affect their rewetting potential and significantly reduce the effective application of restoration treatments. In order to reduce organic matter transformation and loss from the investigated peatland areas, their drainage ditches should be blocked. Additionally, some trees should be removed from their central areas to reduce evapotranspiration.
-
Directory of Open Access Journals (Sweden)
Yanfei Kou
2016-01-01
Full Text Available Water hammer analysis is a fundamental work of pipeline systems design process for water distribution networks. The main characteristics for mine drainage system are the limited space and high cost of equipment and pipeline changing. In order to solve the protection problem of valve-closing water hammer for mine drainage system, a water hammer protection method for mine drainage system based on velocity adjustment of HCV (Hydraulic Control Valve is proposed in this paper. The mathematic model of water hammer fluctuations is established based on the characteristic line method. Then, boundary conditions of water hammer controlling for mine drainage system are determined and its simplex model is established. The optimization adjustment strategy is solved from the mathematic model of multistage valve-closing. Taking a mine drainage system as an example, compared results between simulations and experiments show that the proposed method and the optimized valve-closing strategy are effective.
-
Detecting Subsurface Agricultural Tile Drainage using GIS and Remote Sensing Technique
Budhathoki, M.; Gokkaya, K.; Tank, J. L.; Christopher, S. F.; Hanrahan, B.
2015-12-01
Subsurface tile drainage is a common practice in many of the row crop dominated agricultural lands in the Upper Midwest, which increases yield by making the soil more productive. It is reported that nearly half of all cropland in Indiana benefits from some sort of artificial drainage. However, subsurface tile has a significant negative impact on surface water quality by providing a fast means of transport for nutrients from fertilizers. Therefore, generating spatial data of tile drainage in the field is important and useful for agricultural landscape and hydrological studies. Subsurface tile drains in Indiana's croplands are not widely mapped. In this study, we will delineate subsurface tile drainage in agricultural land in Shatto Ditch watershed, located in Kosciusko County, Indiana. We will use geo-spatial methodology, which was purposed by earlier researchers to detect tile drainage. We will use aerial color-infrared and satellite imagery along with Light Detection and Ranging (LiDAR) data. In order to map tile lines with possible accuracy, we will use GIS-based analysis in combination with remotely sensed data. This research will be comprised of three stages: 1) masking out the potential drainage area using a decision tree rule based on land cover information, soil drainage category, surface slope, and satellite image differencing technique, 2) delineate tile lines using image processing techniques, and 3) check the accuracy of mapped tile lines with ground control points. To our knowledge, this study will be the first to check the accuracy of mapping with ground truth data. Based on the accuracy of results, we will extend the methodology to greater spatial scales. The results are expected to contribute to better characterizing and controlling water pollution sources in Indiana, which is a major environmental problem.
-
DEFF Research Database (Denmark)
Roldin, Maria Kerstin; Mark, Ole; Kuczera, George
2012-01-01
the infiltration rate based on water depth and soil properties for each time step, and controls the removal of water from the urban drainage model. The model is intended to be used to assess the impact of soakaways on urban drainage networks. The model is tested using field data and shown to simulate the behavior......The increased load on urban stormwater systems due to climate change and growing urbanization can be partly alleviated by using soakaways and similar infiltration techniques. However, while soakaways are usually small-scale structures, most urban drainage network models operate on a larger spatial...... of individual soakaways well. Six upscaling methods to aggregate individual soakaway units with varying saturated hydraulic conductivity (K) in the surrounding soil have been investigated. In the upscaled model, the weighted geometric mean hydraulic conductivity of individual allotments is found to provide...
-
Modeling Water Flux at the Base of the Rooting Zone for Soils with Varying Glacial Parent Materials
Naylor, S.; Ellett, K. M.; Ficklin, D. L.; Olyphant, G. A.
2013-12-01
Soils of varying glacial parent materials in the Great Lakes Region (USA) are characterized by thin unsaturated zones and widespread use of agricultural pesticides and nutrients that affect shallow groundwater. To better our understanding of the fate and transport of contaminants, improved models of water fluxes through the vadose zones of various hydrogeologic settings are warranted. Furthermore, calibrated unsaturated zone models can be coupled with watershed models, providing a means for predicting the impact of varying climate scenarios on agriculture in the region. To address these issues, a network of monitoring sites was developed in Indiana that provides continuous measurements of precipitation, potential evapotranspiration (PET), soil volumetric water content (VWC), and soil matric potential to parameterize and calibrate models. Flux at the base of the root zone is simulated using two models of varying complexity: 1) the HYDRUS model, which numerically solves the Richards equation, and 2) the soil-water-balance (SWB) model, which assumes vertical flow under a unit gradient with infiltration and evapotranspiration treated as separate, sequential processes. Soil hydraulic parameters are determined based on laboratory data, a pedo-transfer function (ROSETTA), field measurements (Guelph permeameter), and parameter optimization. Groundwater elevation data are available at three of six sites to establish the base of the unsaturated zone model domain. Initial modeling focused on the groundwater recharge season (Nov-Feb) when PET is limited and much of the annual vertical flux occurs. HYDRUS results indicate that base of root zone fluxes at a site underlain by glacial ice-contact parent materials are 48% of recharge season precipitation (VWC RMSE=8.2%), while SWB results indicate that fluxes are 43% (VWC RMSE=3.7%). Due in part to variations in surface boundary conditions, more variable fluxes were obtained for a site underlain by alluvium with the SWB model (68
-
Soil Water Balance and Irrigation Strategies in an Agricultural District of Southern Italy
Directory of Open Access Journals (Sweden)
Domenico Ventrella
2010-06-01
Full Text Available An efficient management of water resources is considered very important for Mediterranean regions of Italy in order to improve the economical and environmental sustainability of the agricultural activity. The purpose of this study is to analyze the components of soil water balance in an important district included in the regions of Basilicata and Puglia and situated in the Jonical coastal area of Southern Italy and mainly cropped with horticultural crops. The study was performed by using the spatially distributed and physically based model SIMODIS in order to individuate the best irrigation management maximizing the water use efficiency and minimizing water losses by deep percolation and soil evaporation. SIMODIS was applied taking in to account the soil spatial variability and localization of cadastral units for two crops, durum wheat and water melon. For water melon recognition in 2007 a remote sensed image, from SPOT5 satellite, at the spatial resolution of 10 m, has been used. In 2008, a multi-temporal data set was available, from SPOT5 satellite to produce a land cover map for the classes water melon and durum wheat. Water melon cultivation was simulated adopting different water supply managements: rainfed and four irrigation strategies based on (i soil water availability and (ii plant water status adopting a threshold daily stress value. For each management, several water management indicators were calculated and mapped in GIS environment. For seasonal irrigation depth, actual evapotranspiration and irrigation efficiency were also determined. The analysis allowed to individuate the areas particularly sensitive to water losses by deep percolation because of their hydraulic functions characterized by low water retention and large values of saturated hydraulic conductivity. For these areas, the irrigation based on plant water status caused very high water losses by drainage. On the contrary, the irrigation scheduled on soil base allowed to
-
Evaluation of different field methods for measuring soil water infiltration
Pla-Sentís, Ildefonso; Fonseca, Francisco
2010-05-01
Soil infiltrability, together with rainfall characteristics, is the most important hydrological parameter for the evaluation and diagnosis of the soil water balance and soil moisture regime. Those balances and regimes are the main regulating factors of the on site water supply to plants and other soil organisms and of other important processes like runoff, surface and mass erosion, drainage, etc, affecting sedimentation, flooding, soil and water pollution, water supply for different purposes (population, agriculture, industries, hydroelectricity), etc. Therefore the direct measurement of water infiltration rates or its indirect deduction from other soil characteristics or properties has become indispensable for the evaluation and modelling of the previously mentioned processes. Indirect deductions from other soil characteristics measured under laboratory conditions in the same soils, or in other soils, through the so called "pedo-transfer" functions, have demonstrated to be of limited value in most of the cases. Direct "in situ" field evaluations have to be preferred in any case. In this contribution we present the results of past experiences in the measurement of soil water infiltration rates in many different soils and land conditions, and their use for deducing soil water balances under variable climates. There are also presented and discussed recent results obtained in comparing different methods, using double and single ring infiltrometers, rainfall simulators, and disc permeameters, of different sizes, in soils with very contrasting surface and profile characteristics and conditions, including stony soils and very sloping lands. It is concluded that there are not methods universally applicable to any soil and land condition, and that in many cases the results are significantly influenced by the way we use a particular method or instrument, and by the alterations in the soil conditions by the land management, but also due to the manipulation of the surface
-
Directory of Open Access Journals (Sweden)
M. El Bastawesy
2013-04-01
Full Text Available This paper investigates the development of waterlogging in the cultivated and arable areas within typical dryland closed drainage basins (e.g. the Farafra and Baharia Oases, which are located in the Western Desert of Egypt. Multi-temporal remote sensing data of the Landsat Thematic Mapper (TM and Enhanced Thematic Mapper (ETM+ were collected and processed to detect the land cover changes; cultivations, and the extent of water ponds and seepage channels. The Shuttle Radar Topography Mission (SRTM digital elevation model (DEM has been processed to delineate the catchment morphometrical parameters (i.e. drainage networks, catchment divides and surface areas of different basins and to examine the spatial distribution of cultivated fields and their relation to the extracted drainage networks. The soil of these closed drainage basins is mainly shallow and lithic with high calcium carbonate content; therefore, the downward percolation of excess irrigation water is limited by the development of subsurface hardpan, which also saturates the upper layer of soil with water. The subsurface seepage from the newly cultivated areas in the Farafra Oasis has revealed the pattern of buried alluvial channels, which are waterlogged and outlined by the growth of diagnostic saline shrubs. Furthermore, the courses of these waterlogged channels are coinciding with their counterparts of the SRTM DEM, and the recent satellite images show that the surface playas in the downstream of these channels are partially occupied by water ponds. On the other hand, a large water pond has occupied the main playa and submerged the surrounding fields, as a large area has been cultivated within a relatively small closed drainage basin in the Baharia Oasis. The geomorphology of closed drainage basins has to be considered when planning for a new cultivation in dryland catchments to better control waterlogging hazards. The "dry-drainage" concept can be implemented as the drainage and
-
Aspects to consider for optimizing a substrate culture system with drainage recycling
Directory of Open Access Journals (Sweden)
William J Cuervo B
2012-09-01
Full Text Available In Colombia, the soilless system has been implemented in the cut flowers industry, among others, due to soil limitations. The use of substrates as growing media implies to drain around 30% of the applied fertigation solution to avoid the rhizosphere salinization. The drainage solution is spilled out to the soil producing environmental hazards and it might reach the water table; although the drainage solution could be recycled or reuse, depending upon their chemical characteristics. The nutrient uptake by the plants depends upon their phenological stage and the nutrient concentration in the solution; which could lead to ion depletion or accumulation. In general, monovalent ions are withdrawn faster than divalent ones. An efficient drainage treatment involves the automation of sensing and evaluation of ion concentration and recycling the drainage solution. The system should take into account the chemical aspects in the recycled and the new solutions in order to predict the life time of the drainage solution from their EC and pH. The system must be integrated with disinfection methods to avoid the spreading of plant pathogens. This review point out the physiological and technical bases that should be taking into account in a drainage recycling system in established crops under substrates, as a tool to take decisions more efficiently.
-
Review of 'plant available water' aspects of water use efficiency ...
African Journals Online (AJOL)
Review of 'plant available water' aspects of water use efficiency under ... model relating the water supply from a layered soil profile to water demand; the ... and management strategies to combat excessive water losses by deep drainage.
-
Vallée, Romain; Dousset, Sylvie; Billet, David; Benoit, Marc
2014-04-01
Buffer zones such as ponds and ditches are used to reduce field-scale losses of pesticides from subsurface drainage waters to surface waters. The objective of this study was to assess the efficiency of these buffer zones, in particular constructed wetlands, focusing specifically on sorption processes. We modelled the sorption processes of three herbicides [2-methyl-4-chlorophenoxyacetic acid (2,4-MCPA), isoproturon and napropamide] and three fungicides (boscalid, prochloraz and tebuconazole) on four substrates (two soils, sediment and straw) commonly found in a pond and ditch in Lorraine (France). A wide range of Freundlich coefficient (K fads) values was obtained, from 0.74 to 442.63 mg(1 - n) L (n) kg(-1), and the corresponding K foc values ranged from 56 to 3,725 mg(1 - n) L (n) kg(-1). Based on potential retention, the substrates may be classified as straw > sediments > soils. These results show the importance of organic carbon content and nature in the process of sorption. Similarly, the studied pesticides could be classified according to their adsorption capacity as follows: prochloraz > tebuconazole-boscalid > napropamide > MCPA-isoproturon. This classification is strongly influenced by the physico-chemical properties of pesticides, especially solubility and K oc. Straw exhibited the largest quantity of non-desorbable pesticide residues, from 12.1 to 224.2 mg/L for all pesticides. The presence of plants could increase soil-sediment sorption capacity. Thus, establishment and maintenance of plants and straw filters should be promoted to optimise sorption processes and the efficiency of ponds and ditches in reducing surface water pollution.
-
Eertwegh, van den G.A.P.H.
2002-01-01
Keywords
: water and nutrient budget, travel time of drainage water, dual-porosity concept, agricultural nutrient losses, loads to surface water, field-scale experiments, regional-scale -
Differential bare field drainage properties from airborne microwave observations
International Nuclear Information System (INIS)
Bernard, R.; Soars, J.V.; Vidal-Madjar, D.
1986-01-01
Time variations of the surface soil moisture can be monitored using active microwave remote sensing. With the existence of airborne systems, it is now possible to estimate this variable on a regional scale. Data from a helicopter-borne scatterometer show that the surface water content reductions during a 9-day period are quite different from one field to another. A simple model describing the water budget of the soil surface layer due to evaporation and drainage is applied. From this model, a pseudo diffusivity can be calculated for each field using only the remotely sensed data. This new parameter gives a quantitative estimate of the observed drying heterogeneities. (author)
-
Extreme phosphorus losses in drainage from grazed dairy pastures on marginal land.
McDowell, Richard W; Monaghan, Ross M
2015-03-01
With the installation of artificial drainage and large inputs of lime and fertilizer, dairy farming can be profitable on marginal land. We hypothesized that this will lead to large phosphorus (P) losses and potential surface water impairment if the soil has little capacity to sorb added P. Phosphorous was measured in drainage from three "marginal" soils used for dairying: an Organic soil that had been developed out of scrub for 2 yr and used for winter forage cropping, a Podzol that had been developed into pasture for 10 yr, and an intergrade soil that had been in pasture for 2 yr. Over 18 mo, drainage was similar among all sites (521-574 mm), but the load leached to 35-cm depth from the Organic soil was 87 kg P ha (∼89% of fertilizer-P added); loads were 1.7 and 9.0 kg ha from the Podzol and intergrade soils, respectively. Soil sampling to 100 cm showed that added P leached throughout the Organic soil profile but was stratified and enriched in the top 15 cm of the Podzol. Poor P sorption capacity (<5%) in the Organic soil, measured as anion storage capacity, and tillage (causing mineralization and P release) in the Organic and intergrade soils were thought to be the main causes of high P loss. It is doubtful that strategies would successfully mitigate these losses to an environmentally acceptable level. However, anion storage capacity could be used to identify marginal soils with high potential for P loss for the purpose of managing risk. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.
-
Enhancing the efficiency of soil water removal, and in turn crop productivity, on farmland already containing a subsurface drainage system, typically involves installing new drain lines between the old ones. However, before this approach can be attempted, the older drainage pipes need to be located...
-
Soil tension mediates isotope fractionation during soil water evaporation
Gaj, Marcel; McDonnell, Jeffrey
2017-04-01
Isotope tracing of the water cycle is increasing in its use and usefulness. Many new studies are extracting soil waters and relating these to streamflow, groundwater recharge and plant transpiration. Nevertheless, unlike isotope fractionation factors from open water bodies, soil water fractionation factors are poorly understood and until now, only empirically derived. In contrast to open water evaporation where temperature, humidity and vapor pressure gradient define fractionation (as codified in the well-known Craig and Gordon model), soil water evaporation includes additionally, fractionation by matrix effects. There is yet no physical explanation of kinetic and equilibrium fraction from soil water within the soil profile. Here we present a simple laboratory experiment with four admixtures of soil grain size (from sand to silt to clay). Oven-dried samples were spiked with water of known isotopic composition at different soil water contents. Soils were then stored in sealed bags and the headspace filled with dry air and allowed to equilibrate for 24hours. Isotopic analysis of the headspace vapor was done with a Los Gatos Inc. water vapor isotope analyzer. Soil water potential of subsamples were measured with a water potential meter. We show for the first time that soil tension controls isotope fractionation in the resident soil water. Below a Pf 3.5 the δ-values of 18O and 2H of the headspace vapor is more positive and increases with increasing soil water potential. Surprisingly, we find that the relationship between soil tension and equilibrium fractionation is independent of soil type. However, δ-values of each soil type plot along a distinct evaporation line. These results indicate that equilibrium fractionation is affected by soil tension in addition to temperature. Therefore, at high soil water tension (under dry conditions) equilibrium fractionation is not consistent with current empirical formulations that ignore these effects. These findings may have
-
Gumbo, B
2000-01-01
The Harare metropolis in Zimbabwe, extending upstream from Manyame Dam in the Upper Manyame River Basin, consists of the City of Harare and its satellite towns: Chitungwiza, Norton, Epworth and Ruwa. The existing urban drainage system is typically a single-use-mixing system: water is used and discharged to "waste", excreta are flushed to sewers and eventually, after "treatment", the effluent is discharged to a drinking water supply source. Polluted urban storm water is evacuated as fast as possible. This system not only ignores the substantial value in "waste" materials, but it also exports problems to downstream communities and to vulnerable fresh-water sources. The question is how can the harare metropolis urban drainage system, which is complex and has evolved over time, be rearranged to achieve sustainability (i.e. water conservation, pollution prevention at source, protection of the vulnerable drinking water sources and recovery of valuable materials)? This paper reviews current concepts regarding the future development of the urban drainage system in line with the new vision of "Sustainable Cities of the Future". The Harare Metropolis in Zimbabwe is taken as a case, and philosophical options for re-engineering the drainage system are discussed.
-
Barrier erosion control test plan: Gravel mulch, vegetation, and soil water interactions
Energy Technology Data Exchange (ETDEWEB)
Waugh, W.J.; Link, S.O. (Pacific Northwest Lab., Richland, WA (USA))
1988-07-01
Soil erosion could reduce the water storage capacity of barriers that have been proposed for the disposal of near-surface waste at the US Department of Energy's Hanford Site. Gravel mixed into the top soil surface may create a self-healing veneer that greatly retards soil loss. However, gravel admixtures may also enhance infiltration of rainwater, suppress plant growth and water extraction, and lead to the leaching of underlying waste. This report describes plans for two experiments that were designed to test hypotheses concerning the interactive effects of surface gravel admixtures, revegetation, and enhanced precipitation on soil water balance and plant abundance. The first experiment is a factorial field plot set up on the site selected as a soil borrow area for the eventual construction of barriers. The treatments, arranged in a a split-split-plot design structure, include two densities of gravel admix, a mixture of native and introduced grasses, and irrigation to simulate a wetter climate. Changes in soil water storage and plant cover are monitored with neutron moisture probes and point intercept sampling, respectively. The second experiment consists of an array of 80 lysimeters containing several different barrier prototypes. Surface treatments are similar to the field-plot experiment. Drainage is collected from a valve at the base of each lysimeter tube, and evapotranspiration is estimated by subtraction. The lysimeters are also designed to be coupled to a whole-plant gas exchange system that will be used to conduct controlled experiments on evapotranspiration for modeling purposes. 56 refs., 6 figs., 8 tabs.
-
Urban Floods Adaptation and Sustainable Drainage Measures
Directory of Open Access Journals (Sweden)
Helena M. Ramos
2017-11-01
Full Text Available Sustainability is crucial to the urban zones, especially related to the water management, which is vulnerable to flood occurrence. This research applies the procedure contemplated by the Soil Conservation Service (SCS to determine the generated volumes when the impervious areas can exceed the drainage capacity of existing pluvial water networks. Several computational simulations were developed for the current scenario of an existing basin in Lisbon. Using CivilStorm software from Bentley Systems (Bentley EMEA, Bentley Systems International Limited, Dublin, Ireland, it enabled the evaluation of the volumes of flood peaks and the hydraulic behavior of a small hydrographic basin in the continuation of an urbanization process, considering the modification of its superficial impervious parts and the growth of the urbanized area. Several measures are suggested to solve the limited capacity of the existing drainage system. This study analyzes the efficiency of the application of constructive measures, pondering the viability of their effectiveness, individually and combined. The option that best minimizes the effects of the urbanization is the combination of different structural measures, in particular retention ponds, storage blocks, ditches and specific drainage interventions in some parts of the network.
-
Salt and N leaching and soil accumulation due to cover cropping practices
Gabriel, J. L.; Quemada, M.
2012-04-01
Nitrate leaching beyond the root zone can increase water contamination hazards and decrease crop available N. Cover crops used in spite of fallow are an alternative to reduce nitrate contamination in the vadose zone, because reducing drainage and soil mineral N accumulation. Cover crops can improve important characteristics in irrigated land as water retention capacity or soil aggregate stability. However, increasing evapotranspiration and consequent drainage below the root system reduction, could lead to soil salt accumulation. Salinity affects more than 80 million ha of arable land in many areas of the world, and one of the principal causes for yield reduction and even land degradation in the Mediterranean region. Few studies dealt with both problems at the same time. Therefore, it is necessary a long-term evaluation of the potential effect on soil salinity and nitrate leaching, in order to ensure that potential disadvantages that could originate from soil salt accumulation are compensated with all advantages of cover cropping. A study of the soil salinity and nitrate leaching was conducted during 4 years in a semiarid irrigated agricultural area of Central Spain. Three treatments were studied during the intercropping period of maize (Zea mays L.): barley (Hordeum vulgare L.), vetch (Vicia villosa L.) and fallow. Cover crops were killed in March allowing seeding of maize of the entire trial in April, and all treatments were irrigated and fertilised following the same procedure. Before sowing, and after harvesting maize and cover crops, soil salt and nitrate accumulation was determined along the soil profile. Soil analysis was conducted at six depths every 0.20 m in each plot in samples from four 0 to 1.2-m depth holes dug. The electrical conductivity of the saturated paste extract and soil mineral nitrogen was measured in each soil sample. A numerical model based on the Richards water balance equation was applied in order to calculate drainage at 1.2 m depth
-
Fraters, D.; Boom, G.J.F.L.; Boumans, L.J.M.; Weerd, H. de; Wolters, M.
2017-01-01
The solute concentration in the subsoil beneath the root zone is an important parameter for leaching assessment. Drainage centrifugation is considered a simple and straightforward method of determining soil solution chemistry. Although several studies have been carried out to determine whether this
-
Soil water balance in different densities of Pinus taeda in Southern Brazil
Directory of Open Access Journals (Sweden)
Jorge Luiz Moretti Souza
2016-04-01
Full Text Available This study aimed to quantify and compare water balance components over the course of a year for different Pinus taeda planting densities in an oxisol in southern Brazil. This experiment was conducted on 6-year-old trees in a clay oxisol at the Monte Alegre Farm, a property of the Klabin Company. The experimental design was a randomized block with four replicates and five treatments with different amounts of soil coverage: T100 (100% coverage - standard planting coverage; (T75, 75; T50, 50; and T25, 25%, and; T0 (without cover - clearcutting. The soil water storage and actual evapotranspiration under non-standard conditions were determined in a weekly estimated soil water balance (SWB with measured components. By the end of the year, the treatments had not reached field capacity or wilting point storage. The average value of total downward drainage was 100.2 mm, and the highest values occurred in the T75 and T100 treatments. The lowest population density (T25 had the highest actual evapotranspiration (ETr, due to the growth of the remaining Pinus taeda trees. The highest evapotranspiration occurred in September, due to the resumption of Pinus taeda growth.
-
Juvenile Southern Pine Response to Fertilization Is Influenced by Soil Drainage and Texture
Directory of Open Access Journals (Sweden)
Timothy J. Albaugh
2015-08-01
Full Text Available We examined three hypotheses in a nutrient dose and application frequency study installed in juvenile (aged 2–6 years old Pinus stands at 22 sites in the southeastern United States. At each site, eight or nine treatments were installed where nitrogen was applied at different rates (0, 67, 134, 268 kg ha−1 and frequencies (0, 1, 2, 4 and 6 years in two or four replications. Phosphorus was applied at 0.1 times the nitrogen rate and other elements were added as needed based on foliar nutrient analysis to insure that nutrient imbalances were not induced with treatment. Eight years after treatment initiation, the site responses were grouped based on texture and drainage characteristics: soil group 1 consisted of poorly drained soils with a clayey subsoil, group 2 consisted of poorly to excessively drained spodic soils or soils without a clay subsoil, and group 3 consisted of well-drained soils with a clayey subsoil. We accepted the first hypothesis that site would be a significant factor explaining growth responses. Soil group was also a significant factor explaining growth response. We accepted our second hypothesis that the volume growth-cumulative dose response function was not linear. Volume growth reached an asymptote in soil groups 1 and 3 between cumulative nitrogen doses of 300–400 kg ha−1. Volume growth responses continued to increase up to 800 kg ha−1 of cumulatively applied nitrogen for soil group 2. We accepted our third hypothesis that application rate and frequency did not influence the growth response when the cumulative nitrogen dose was equivalent. There was no difference in the growth response for comparisons where a cumulative nitrogen dose of 568 kg ha−1 was applied as 134 kg ha−1 every two years or as 269 kg ha−1 every four years, or where 269 kg ha−1 of nitrogen was applied as four applications of 67 kg ha−1 every two years or as two applications of 134 kg ha−1 every four years. Clearly, the sites examined
-
Heavy metal displacement in chelate-irrigated soil during phytoremediation
Madrid, F.; Liphadzi, M. S.; Kirkham, M. B.
2003-03-01
Heavy metals in wastewater sewage sludge (biosolids), applied to land, contaminate soils. Phytoremediation, the use of plants to clean up toxic heavy metals, might remove them. Chelating agents are added to soil to solubilize the metals for enhanced phytoextraction. Yet no studies follow the displacement and leaching of heavy metals in soil with and without roots following solubilization with chelates. The objective of this work was to determine the mobility of heavy metals in biosolids applied to the surface of soil columns (76 cm long; 17 cm diam.) with or without plants (barley; Hordeum vulgare L.). Three weeks after barley was planted, all columns were irrigated with the disodium salt of the chelating agent, EDTA (ethylenediamine tetraacetic acid) (0.5 g/kg soil). Drainage water, soil, and plants were analyzed for heavy metals (Cd, Cu, Fe, Mn, Ni, Pb, Zn). Total concentrations of the heavy metals in all columns at the end of the experiment generally were lower in the top 30 cm of soil with EDTA than without EDTA. The chelate increased concentrations of heavy metals in shoots. With or without plants, the EDTA mobilized Cd, Fe, Mn, Ni, Pb, and Zn, which leached to drainage water. Drainage water from columns without EDTA had concentrations of these heavy metals below detection limits. Only Cu did not leach in the presence of EDTA. Even though roots retarded the movement of Cd, Fe, Mn, Ni, Pb, and Zn through the EDTA-treated soil from 1 d (Cd) to 5 d (Fe), the drainage water from columns with EDTA had concentrations of Cd, Fe, Mn, and Pb that exceeded drinking water standards by 1.3, 500, 620, and 8.6 times, respectively. Because the chelate rendered Cd, Fe, Mn, Ni, Pb, and Zn mobile, it is suggested that the theory for leaching of soluble salts, put forward by Nielsen and associates in 1965, could be applied to control movement of the heavy metals for maximum uptake during chelate-assisted phytoremediation.
-
Review of 'plant available water' aspects of water use efficiency ...
African Journals Online (AJOL)
processes in the soil, has greatly enhanced understanding of the system, ... and management strategies to combat excessive water losses by deep drainage. ... risk clay and duplex soils and high runoff losses, in-field rainwater harvesting ...
-
Li, Chunyan
2017-11-01
Prestressed reinforced concrete pipe has the advantages of good bending resistance, good anti-corrosion, anti-seepage, low price and so on. It is very common in municipal water supply and drainage engineering. This paper mainly explore the analyze the construction technology of the prestressed reinforced concrete pipe in municipal water supply and drainage engineering.
-
A critical review of integrated urban water modelling – Urban drainage and beyond
DEFF Research Database (Denmark)
Bach, Peter M.; Rauch, Wolfgang; Mikkelsen, Peter Steen
2014-01-01
considerations (e.g. data issues, model structure, computational and integration-related aspects), common methodology for model development (through a systems approach), calibration/optimisation and uncertainty are discussed, placing importance on pragmatism and parsimony. Integrated urban water models should......Modelling interactions in urban drainage, water supply and broader integrated urban water systems has been conceptually and logistically challenging as evidenced in a diverse body of literature, found to be confusing and intimidating to new researchers. This review consolidates thirty years...... of research (initially driven by interest in urban drainage modelling) and critically reflects upon integrated modelling in the scope of urban water systems. We propose a typology to classify integrated urban water system models at one of four ‘degrees of integration’ (followed by its exemplification). Key...
-
Modeling Water Pollution of Soil
Directory of Open Access Journals (Sweden)
V. Doležel
2008-01-01
Full Text Available The government of the Czech Republic decided that in the location to the west of Prague, capital city of the Czech Republic, some deep mines should be closed because of their low efficiency of coal mined i.e. small amounts and low quality of the coal extracted in the final stage of mining. The locations near Prague influenced the decision to do maintenance on the abandoned mines, as the thread of soil pollution was unacceptably high in the neighborhood of the capital city. Before the mines were closed it was necessary to separate existed extensive horizontal location of salt water below a clay layer in order not to deteriorate the upper fresh water. The salt water could not be allowed to pollute the upper layer with the fresh water, as many wells in villages in the neighborhood of the former mines would be contaminated. Two horizontal clay layers (an insulator and a semi-insulator separated the two horizons containing salt water and fresh water. Before starting deep mining, vertical shafts had to be constructed with concrete linings to enable the miners to access the depths. The salt water was draining away throughout the existence of the mine. The drainage was designed very carefully to avoid possible infiltration of salt water into the upper horizon. Before the mines were abandoned it was necessary to prevent contact between the two kinds of waters in the shafts. Several options were put forward, the most efficient of which appeared to be one that proposed filling the shafts with spoil soil and creating a joint seal made of disparate material at the interface between the salt water and fresh water to create a reliable stopper. The material for the spoil soil was delivered from deposits located not far from the shafts. This material consisted of a variety of grains of sand, big boulders of slate, slaty clay, sandstone, etc.. Chemical admixtures were considered to improve the flocculation of the filling material. The stopper was positioned at a
-
Land drainage and restoration of land after NCB opencast mining
Energy Technology Data Exchange (ETDEWEB)
Bragg, N.
The author outlines the MAFF Field Drainage Research Unit's research into drainage of reinstated land. Current investigations have aimed at identifying the problems of reinstated soil and how they affect drainage design. Experiments on efficiency of permeable field drains and non-permeable field drains are mentioned. Further work is needed to examine long-term effects of storage on soil structure and whether existing drainage can be revitalised by secondary treatment.
-
Energy Technology Data Exchange (ETDEWEB)
Wu, Q.; Li, D.; Di, Z.Q.; Miao, Y.; Zhao, S.Q.; Guo, Q.W. [CUMT, Beijing (China). Resource Exploitation Engineering College
2005-10-01
The geological condition of coalfield is much complex in China. With increasing in mining depth and drainage amount, the contradiction of drainage, water supply and environmental protection is becoming more and more serious. However, the contradiction can be solved by the scientific management of optimizing combination of drainage, water supply and environmental protection. The Philip multiple objectives simplex method used in this article has searched for a possible solution at the first step, and then it goes on searching to find out whether there is a weight number that can lead the solution to the biggest. It can reduce the randomness and difficulty of traditional weight method which determine the weight number artificially. Some beneficial coefficients are vague and the number is larger in the model of water resource dispatch. So the vague layer analysis method can consider these vague factors fully, combining the qualitative and quantitative analysis together. Especially, this method can quantify the experiential judgement of policy decider, and it will turn to be more suitable if the structure of objective factors is complex or the necessary data are absent. In the paper, the two methods above are used to solve the plans of drainage, water supply and optimizing distribution of water resource in the Zhengzhou mining district.
-
Evaluation of Critical Parameters to Improve Slope Drainage System
Directory of Open Access Journals (Sweden)
Yong Weng Long
2017-01-01
Full Text Available This study focuses on identifying and evaluating critical parameters of various drainage configurations, arrangement, and filter which affect the efficiency of water draining system in slopes. There are a total of seven experiments with different types of homogeneous soil, drainage envelope, filter material, and quantity of pipes performed utilizing a model box with a dimension of 0.8 m × 0.8 m × 0.6 m. The pipes were orientated at 5 degrees from the horizontal. Rainfall event was introduced via a rainfall simulator with rainfall intensity of 434.1 mm/h. From the experiments performed, the expected outcomes when utilizing double pipes and geotextile as envelope filter were verified in this study. The results obtained from these experiments were reviewed and compared with Chapter 14 “Subsurface Drainage Systems” of DID’s Irrigation and Agricultural Drainage Manual of Malaysia and the European standard. It is recommended that the pipe installed in the slope could be wrapped with geotextile and in tandem with application of granular filter to minimize clogging without affecting the water discharge rate. Terzaghi’s filter criteria could be followed closely when deciding on new materials to act as aggregate filter. A caging system could be introduced as it could maintain the integrity of the drainage system and could ease installation.
-
Long-term monitoring of nitrate-N transport to drainage from three agricultural clayey till fields
Ernstsen, V.; Olsen, P.; Rosenbom, A. E.
2015-01-01
The application of nitrogen (N) fertilisers to crops grown on tile-drained fields is necessary to sustain most modern crop production, but poses a risk to the aquatic environment since tile drains facilitate rapid transport pathways with no significant reduction in nitrate. To maintain the water quality of the aquatic environment and the provision of food from highly efficient agriculture in line with the EU's Water Framework Directive and Nitrates Directive, field-scale knowledge is imperative if there is to be differentiated N-regulation in future. This study describes nitrate-N leaching to drainage based on coherent monitoring of nitrate-N concentrations, the climate, the groundwater table and crop-specific parameters obtained over eleven years (2001-2011) at three subsurface-drained clayey till fields (1.3-2.3 ha). The monitoring results showed significant field differences in nitrate-N transport to drainage. Not only were these caused by periods of bare soil after short-season crops and N-fixing crops (pea), which have been shown to generate high nitrate-N concentrations in drainage, but by the hydrogeological field conditions that were shown to be the controlling factor of nitrate-N transport to drainage. The fields had the following characteristics: (A) the lowest mass transport (13 kg N ha-1) and fertiliser input had short-term and low-intensity drainage with the highest nitrate-N concentrations detected, representing 40% of net precipitation (226 mm) combined with low air temperatures, (B) the medium mass transport (14 kg N ha-1) had medium-term and medium-intensity drainage, representing 42% of net precipitation (471 mm) combined with periods of both low and higher air temperatures, (C) the highest mass transport (19 kg N ha-1) had long-term drainage, representing 68% of net precipitation (617 mm), but had the highest potential for in-situ soil denitrification and post-treatment (e.g. constructed wetlands) due to long periods with both high water
-
Directory of Open Access Journals (Sweden)
Gardić Vojka R.
2015-01-01
Full Text Available Mining and copper production in Bor, in the past hundred years, had a huge impact on the environment of town, but also in a wide region. In the area of Bor, in the zone of Mining and Smelting Company (RTB activity, over 29,000 ha of land under forests and fields is degraded. The area of degraded agricultural land in the Bor municipality is over 60% of total agricultural land. Wastewater, generated in the sites of RTB Bor, pollute the Bor River and Krivelj River, which still flow into the Timok River and Danube River. These pollutions are often presented by low pH value, increased content of heavy metal ions, suspended particles and fine particles of flotation tailings, which is deposited in the valleys of these rivers on the area of over 2000 hectares. During the decades of exploitation of ore from the open pit Bor at different locations ("Visoki Planir" - also called “Oštreljski planir”, "Severni planir" dump of ore body "H" (RTH gangue and tailings were delayed. The largest amount of tailings, about 150 million tons, was postponed on location Visoki planir. The effect of the mining waste and the impact of the whole process of processing copper ore to the final products on the environment, was conducted during the 4th study period of the project "Management of mining waste-tailing dump in the Bor region," supported by the Japan Society for the Promotion Science (Eng. Japan Society for the Promotion of Science and the Japan international cooperation Agency and the Ministry of environment, Mining and Spatial planning of the Republic of Serbia. Influence of season on the level of pollutants in soil and water, the impact on water quality in the river Timok and the River Danube, was conducted during first three periods of project. This paper presents the results of the third study period. The third period of research, which was conducted over a period of 17. 10. 2012 to 17. 01.2013 year, included a review of pollution sources and define their
-
Development of a regional hydrologic soil model and application to the Beerze-Reusel drainage basin
International Nuclear Information System (INIS)
Kolditz, O.; Du, Y.; Buerger, C.; Delfs, J.; Kuntz, D.; Beinhorn, M.; Hess, M.; Wang, W.; Grift, B. van der; Stroet, C. te
2007-01-01
The soil compartment is an important interface between the atmosphere and the subsurface hydrosphere. In this paper a conceptual approach for regional hydrologic soil modelling (RHSM) is presented, which provides two important qualities for modelling. First, the soil compartment is directly coupled to the atmosphere via the land surface and to the aquifers. Second, extremely fine (5 cm vertical) resolutions of the soil system can be realized at regional scales (several hundreds of km 2 ). This high-resolution modelling could be achieved by parallel computation techniques. The RHSM approach is applied to the Beerze-Reusel drainage basin, which belongs to the Meuse River basin. Moisture transport in the soil system was calculated with extremely high vertical resolution at a regional scale based on rainfall-evaporation data for the year 2000. As a result, highly resolved regional groundwater recharge pattern addressing the heterogeneity of soil systems could be determined. - A real case application of concept of regional hydrologic soil modelling is presented
-
Improvements to measuring water flux in the vadose zone.
Masarik, Kevin C; Norman, John M; Brye, Kristofor R; Baker, John M
2004-01-01
Evaluating the impact of land use practices on ground water quality has been difficult because few techniques are capable of monitoring the quality and quantity of soil water flow below the root zone without disturbing the soil profile and affecting natural flow processes. A recently introduced method, known as equilibrium tension lysimetry, was a major improvement but it was not a true equilibrium since it still required manual intervention to maintain proper lysimeter suction. We addressed this issue by developing an automated equilibrium tension lysimeter (AETL) system that continuously matches lysimeter tension to soil-water matric potential of the surrounding soil. The soil-water matric potential of the bulk soil is measured with a heat-dissipation sensor, and a small DC pump is used to apply suction to a lysimeter. The improved automated approach reported here was tested in the field for a 12-mo period. Powered by a small 12-V rechargeable battery, the AETLs were able to continuously match lysimeter suction to soil-water matric potential for 2-wk periods with minimal human attention, along with the added benefit of collecting continuous soil-water matric potential data. We also demonstrated, in the laboratory, methods for continuous measurement of water depth in the AETL, a capability that quantifies drainage on a 10-min interval, making it a true water-flux meter. Equilibrium tension lysimeters have already been demonstrated to be a reliable method of measuring drainage flux, and the further improvements have created a more effective device for studying water drainage and chemical leaching through the soil matrix.
-
Travar, Igor; Andreas, Lale; Kumpiene, Jurate; Lagerkvist, Anders
2015-01-01
The aim of this study was to evaluate the drainage water quality from a landfill cover built with secondary construction materials (SCM), fly ash (FA), bottom ash (BA) sewage sludge, compost and its changes over time. Column tests, physical simulation models and a full scale field test were conducted. While the laboratory tests showed a clear trend for all studied constituents towards reduced concentrations over time, the concentrations in the field fluctuated considerably. The primary contaminants in the drainage water were Cl(-), N, dissolved organic matter and Cd, Cu, Ni, Zn with initial concentrations one to three orders of magnitude above the discharge values to the local recipient. Using a sludge/FA mixture in the protection layer resulted in less contaminated drainage water compared to a sludge/BA mixture. If the leaching conditions in the landfill cover change from reduced to oxidized, the release of trace elements from ashes is expected to last about one decade longer while the release of N and organic matter from the sludge can be shortened with about two-three decades. The observed concentration levels and their expected development over time require drainage water treatment for at least three to four decades before the water can be discharged directly to the recipient. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.
-
Transport assessment - arid: measurement and prediction of water movement below the root zone
International Nuclear Information System (INIS)
Gee, G.W.; Kirkham, R.R.
1984-01-01
The amount of water transported below the root-zone and available for drainage (recharge) must be known in order to quantify the potential for leaching at low-level waste sites. Under arid site conditions, we quantified drainage by using weighing lysimeters containing sandy soil and measured 6 and 11 cm of drainage for a 1-yr period (June 1983-May 1984) from grass-covered and bare-soil surfaces, respectively. Precipitation during this period at our test site near Richland, Washington, was 25 cm. Similar drainage values were estimated from neutron probe measurements of water content profile changes in an adjacent grass-covered site. These data suggest that significant amounts of drainage can occur at arid sites when soils are coarse textured and precipitation occurs during fall and winter months. Model simulations predicted drainage values comparable to those measured with our weighing lysimeters. Long-term, 500- to 1000-yr predictions of leaching are possible with our model simulations. However, additional studies are needed to evaluate the effect of soil variability and stochastic rainfall inputs on drainage estimates, particularly for arid sites
-
Göckede, Mathias; Kittler, Fanny; Kwon, Min Jung; Burjack, Ina; Heimann, Martin; Kolle, Olaf; Zimov, Nikita; Zimov, Sergey
2017-12-01
Hydrologic conditions are a key factor in Arctic ecosystems, with strong influences on ecosystem structure and related effects on biogeophysical and biogeochemical processes. With systematic changes in water availability expected for large parts of the northern high-latitude region in the coming centuries, knowledge on shifts in ecosystem functionality triggered by altered water levels is crucial for reducing uncertainties in climate change predictions. Here, we present findings from paired ecosystem observations in northeast Siberia comprising a drained and a control site. At the drainage site, the water table has been artificially lowered by up to 30 cm in summer for more than a decade. This sustained primary disturbance in hydrologic conditions has triggered a suite of secondary shifts in ecosystem properties, including vegetation community structure, snow cover dynamics, and radiation budget, all of which influence the net effects of drainage. Reduced thermal conductivity in dry organic soils was identified as the dominating drainage effect on energy budget and soil thermal regime. Through this effect, reduced heat transfer into deeper soil layers leads to shallower thaw depths, initially leading to a stabilization of organic permafrost soils, while the long-term effects on permafrost temperature trends still need to be assessed. At the same time, more energy is transferred back into the atmosphere as sensible heat in the drained area, which may trigger a warming of the lower atmospheric surface layer.
-
Radimy, Raymond Tojo; Dudoignon, Patrick; Hillaireau, Jean Michel; Deboute, Elise
2013-01-01
The French Atlantic marshlands, reclaimed since the Middle Age, have been successively used for extensive grazing and more recently for cereal cultivation from 1970. The soils have acquired specific properties which have been induced by the successive reclaiming and drainage works and by the response of the clay dominant primary sediments, that is, structure, moisture, and salinity profiles. Based on the whole survey of the Marais Poitevin and Marais de Rochefort and in order to explain the mechanisms of marsh soil behavior, the work focuses on two typical spots: an undrained grassland since at least 1964 and a drained cereal cultivated field. The structure-hydromechanical profiles relationships have been established thanks to the clay matrix shrinkage curve. They are confronted to the hydraulic functioning including the fresh-to-salt water transfers and to the recording of tensiometer profiles. The CE1/5 profiles supply the water geochemical and geophysical data by their better accuracy. Associated to the available water capacity calculation they allow the representation of the parallel evolution of the residual available water capacity profiles and salinity profiles according to the plant growing and rooting from the mesophile systems of grassland to the hygrophile systems of drained fields.
-
Han, Xiao-Qing; Xiao, Xi-Yuan; Guo, Zhao-Hui; Xie, Ye-Hua; Zhu, Hui-Wen; Peng, Chi; Liang, Yu-Qin
2018-05-03
Agricultural soils contaminated with cadmium (Cd) pose a risk to receiving surface water via drainage or runoff. A 90-day laboratory incubation experiment was conducted to investigate the release characteristics and transformation of Cd from contaminated paddy soil amended with agrochemical (NPK fertilizer) and lime (L) under water management regimes of continuous flooding (F) and drying-wetting cycles (DW). The result showed that the dissolved Cd concentrations in overlying water of the fertilizer treatment under flooding (NPK+F) and drying-wetting (NPK+DW) reached up to 81.0 μg/L and 276 μg/L, and were much higher than that from the corresponding controls without NPK fertilizer addition at the end of experiment. The Cd concentration showed significantly negative correlation with overlying water pH, but positive correlation with soil redox potential and concentrations of dissolved total nitrogen, sulfate and manganese in overlying water (P < 0.05), indicating that drying-wetting cycles and N fertilizer addition may enhance soil Cd release. The Cd concentrations in overlying water from all treatments except NPK+L+F treatment exceeded the Cd threshold limit of Chinese Environmental Quality Standards for Surface Water (10 μg/L Grade V) and poses potential risk to surface water quality. Meanwhile, the proportion of Cd in the acid-soluble fraction from all incubated soil except NPK+L+F treatment increased compared to before incubation. The results indicated that continuous flooding was a reasonable water management candidate coupled with lime addition for immobilizing soil Cd. Copyright © 2018 Elsevier Inc. All rights reserved.
-
Modeling of the loss of soil by water erosion of the basin of the River V Anniversary Cuyaguateje
International Nuclear Information System (INIS)
Alonso, Gustavo R.; Días, Jorge; Ruíz, Maria Elena
2008-01-01
The complexity of the processes involved in water erosion of soils has led to widespread use of models with high level of empiricism. However, there are few applications based on models with a considerable physical basis in this field. The purpose of this work is to evaluate the potential of a model of physical basis for estimating soil loss by erosion basin-scale and analyze the behavior of the variables in this model response. The study area was located in the Sub-basin V anniversary, which belongs to the basin of the Cuyaguateje, in the province of Pinar de Rio. You were a database of physical properties of main soils of the basin, the series-temporales of solid spending and runoff measured at River, and rain recorded by a network of rain gauges across the basin. The equation of physical basis used was the sediment transport model (STM), according to Biesemans (2000). As input variables of the model were obtained the following maps: the digital elevation model, accumulative area of drainage, drainage, land use, surface water retention capacity, retention of moisture and hydraulic conductivity of saturation curve. Soil loss was obtained per pixel, and these were correlated with each time series. The results show that the process can be extended to other sub-basins without the need to validate all the variables involved
-
Fraters, Dico; Boom, Gerard J F L; Boumans, Leo J M; de Weerd, Henk; Wolters, Monique
2017-02-01
The solute concentration in the subsoil beneath the root zone is an important parameter for leaching assessment. Drainage centrifugation is considered a simple and straightforward method of determining soil solution chemistry. Although several studies have been carried out to determine whether this method is robust, hardly any results are available for loess subsoils. To study the effect of centrifugation conditions on soil moisture recovery and solute concentration, we sampled the subsoil (1.5-3.0 m depth) at commercial farms in the loess region of the Netherlands. The effect of time (20, 35, 60, 120 and 240 min) on recovery was studied at two levels of the relative centrifugal force (733 and 6597g). The effect of force on recovery was studied by centrifugation for 35 min at 117, 264, 733, 2932, 6597 and 14,191g. All soil moisture samples were chemically analysed. This study shows that drainage centrifugation offers a robust, reproducible and standardised way for determining solute concentrations in mobile soil moisture in silt loam subsoils. The centrifugal force, rather than centrifugation time, has a major effect on recovery. The maximum recovery for silt loams at field capacity is about 40%. Concentrations of most solutes are fairly constant with an increasing recovery, as most solutes, including nitrate, did not show a change in concentration with an increasing recovery.
-
Mapping regional soil water erosion risk in the Brittany-Loire basin for water management agency
Degan, Francesca; Cerdan, Olivier; Salvador-Blanes, Sébastien; Gautier, Jean-Noël
2014-05-01
quantified: the soil factors (soil sealing, erodibility and runoff), the rate of land cover over three years for each season and for 77 land use classes, the topographic factor (slope and drainage area) and the climate hazard (seasonal amount and rainfall erosivity). These modifications of the original MESALES model allow to better represent erosion risk for arable and bare land. We validated model results by stakeholder consultations and meetings over all the study area. The model has finally been modified taking into account validation results. Results are provided with a spatial resolution of 1 km, and then integrated into 2121 catchments. An erosion risk map for each season and an annual erosion risk map are produced. These new maps allow to organize in hierarchy 2121 catchments into three erosion risk classes. In the annual erosion risk map, 347 catchments have the highest erosion risk, which corresponds to 16 % of total Brittany-Loire basin area. Water management agency now uses these maps to identify priority areas and to plan specific preservation practices.
-
Sorbents for phosphate removal from agricultural drainage water
DEFF Research Database (Denmark)
Lyngsie, Gry
Subsurface transport of phosphate (P) from fertilized agricultural fields to freshwaters may lead to eutrophication and reduced biodiversity in inland waters. Mitigation of eutrophic waters is difficult and costly. Reduction of P export to surface waters using filters installed in agricultural...... drains comprising P sorbing materials (PSM) may be a more efficient and cost-effective way to improve water quality. Several materials have been proposed as PSMs for use for cleaning agricultural drainage water. The objective of the present study was to provide data on sorption behavior among a variety...... of PSMs in order to select a material that can quickly remove P from runoff water at both base and peak flow. This was done by screening 15 “local” PSMs’ for their ability to sorb and retain low orthophosphate concentrations (0-161 µM) at short equilibration time (
-
Yang, Yun; Anderson, Martha C.; Gao, Feng; Hain, Christopher; Kustas, William P.; Meyers, Tilden P.; Crow, Wade; Finocchiaro, Raymond G.; Otkin, Jason; Sun, Liang; Yang, Yang
2017-01-01
Soil drainage is a widely used agricultural practice in the midwest USA to remove excess soil water to potentially improve the crop yield. Research shows an increasing trend in baseflow and streamflow in the midwest over the last 60 years, which may be related to artificial drainage. Subsurface drainage (i.e., tile) in particular may have strongly contributed to the increase in these flows, because of its extensive use and recent gain in the popularity as a yield-enhancement practice. However, how evapotranspiration (ET) is impacted by tile drainage on a regional level is not well-documented. To explore spatial and temporal ET patterns and their relationship to tile drainage, we applied an energy balance-based multisensor data fusion method to estimate daily 30-m ET over an intensively tile-drained area in South Dakota, USA, from 2005 to 2013. Results suggest that tile drainage slightly decreases the annual cumulative ET, particularly during the early growing season. However, higher mid-season crop water use suppresses the extent of the decrease of the annual cumulative ET that might be anticipated from widespread drainage. The regional water balance analysis during the growing season demonstrates good closure, with the average residual from 2005 to 2012 as low as -3 mm. As an independent check of the simulated ET at the regional scale, the water balance analysis lends additional confidence to the study. The results of this study improve our understanding of the influence of agricultural drainage practices on regional ET, and can affect future decision making regarding tile drainage systems.
-
3D soil water nowcasting using electromagnetic conductivity imaging and the ensemble Kalman filter
Huang, Jingyi; McBratney, Alex B.; Minasny, Budiman; Triantafilis, John
2017-06-01
Mapping and immediate forecasting of soil water content (θ) and its movement can be challenging. Although inversion of apparent electrical conductivity (ECa) measured by electromagnetic induction to calculate depth-specific electrical conductivity (σ) has been used, it is difficult to apply it across a field. In this paper we use a calibration established along a transect, across a 3.94-ha field with varying soil texture, using an ensemble Kalman filter (EnKF) to monitor and nowcast the 3-dimensional θ dynamics on 16 separate days over a period of 38 days. The EnKF combined a physical model fitted with θ measured by soil moisture sensors and an Artificial Neural Network model comprising σ generated by quasi-3d inversions of DUALEM-421S ECa data. Results showed that the distribution of θ was controlled by soil texture, topography, and vegetation. Soil water dried fastest at the beginning after the initial irrigation event and decreased with time and soil depth, which was consistent with classical soil drying theory and experiments. It was also found that the soil dried fastest in the loamy and duplex soils present in the field, which was attributable to deep drainage and preferential flow. It was concluded that the EnKF approach can be used to improve the irrigation efficiency by applying variable irrigation rates across the field. In addition, soil water status can be nowcasted across large spatial extents using this method with weather forecast information, which will provide guidance to farmers for real-time irrigation management.
-
Jones, Adele M; Xue, Youjia; Kinsela, Andrew S; Wilcken, Klaus M; Collins, Richard N
2016-03-15
Donnan dialysis has been applied to forty filtered drainage waters collected from five coastal lowland acid sulfate soil (CLASS) catchments across north-eastern NSW, Australia. Despite having average pH values70%) as negatively-charged complexes. In contrast, the speciation of the divalent trace metals Co, Mn, Ni and Zn was dominated by positively-charged complexes and was strongly correlated with the alkaline earth metals Ca and Mg. Thermodynamic equilibrium speciation calculations indicated that natural organic matter (NOM) complexes dominated Fe(III) speciation in agreement with that obtained by Donnan dialysis. In the case of Fe(II), however, the free cation was predicted to dominate under thermodynamic equilibrium, whilst our results indicated that Fe(II) was mainly present as neutral or negatively-charged complexes (most likely with sulfate). For all other divalent metals thermodynamic equilibrium speciation calculations agreed well with the Donnan dialysis results. The proportion of Al and REEs predicted to be negatively-charged was also grossly underestimated, relative to the experimental results, highlighting possible inaccuracies in the stability constants developed for these trivalent Me(SO4)2(-) and/or Me-NOM complexes and difficulties in modeling complex environmental samples. These results will help improve metal mobility and toxicity models developed for CLASS-affected environments, and also demonstrate that Australian CLASS environments can discharge REEs at concentrations an order of magnitude greater than previously reported. Copyright © 2015 Elsevier B.V. All rights reserved.
-
Directory of Open Access Journals (Sweden)
Andy R. Erwin Wijaya
2010-03-01
Full Text Available ABSTRAK Kegiatan pertambangan batubara umumnya dapat menimbulkan dampak negatif terhadap lingkungan di lokasi penambangan. Salah satu dampak negatif yang signifikan adalah terjadinya pencemaran air asam tambang yang dapat merusak fungsi lingkungan seperti komponen air dan tanah. Umumnya lokasi tambang batubara yang berpotensi besar sebagai sumber terbentuknya air asam tambang adalah kolam penampungan air tambang (water pond dan tempat penimbunan material buangan sulfida (waste dump. Penelitian ini bertujuan untuk mengendalikan rembesan air asam tambang yang berasal dari kolam penampungan air (water pond dan mengurangi terbentuknya air asam tambang pada tempat penimbunan material buangan sulfida (waste dunp. Sistem pengendalian pencemaran air asam tambang meliputi pengolahan air asam tambang (water pond dan pengelolaan material sulfida (waste dump. Metode pengolahan air asam tambang adalah menetralisasi air asam dengan reagen alkali. Reagen alkali yang paling efektif dan ekonomis adalah batugamping (kalsium karbonat. Jumlah batugamping yang dibutuhkan untuk menetralkan air asam lambang pada water pond (5040 m3 sebesar 104,56 kg. Pengelolaan material buangan sulfida (waste dump adalah menerapkan model encapsulation in-pit disposal. Hal ini sangat efektif untuk mencegah terbentuknya air asam tambang. Material perlapisan yang digunakan adalah lempung (clay, karena mempunyai nilai permeabilitas yang sangat kecil yaitu sebesar 2,3148 x 10-9 m/det dan ketersediaannya mencukupi. ABSTRACT Coal mining activity generally can generate negative impact to environment on mining location. One of the negative impact is contamination of acid mine drainage which able to destroy environment and ecosystem as water and soil. High potency source of acid mine drainage formed on coal mining location are water pond and waste dump. This aim of the research are control of acid mine drainage from water pond and prevention of acid mine drainage formed on the waste dump
-
Quasi 3D modelling of water flow in the sandy soil
Rezaei, Meisam; Seuntjens, Piet; Joris, Ingeborg; Boënne, Wesley; De Pue, Jan; Cornelis, Wim
2016-04-01
Monitoring and modeling tools may improve irrigation strategies in precision agriculture. Spatial interpolation is required for analyzing the effects of soil hydraulic parameters, soil layer thickness and groundwater level on irrigation management using hydrological models at field scale. We used non-invasive soil sensor, a crop growth (LINGRA-N) and a soil hydrological model (Hydrus-1D) to predict soil-water content fluctuations and crop yield in a heterogeneous sandy grassland soil under supplementary irrigation. In the first step, the sensitivity of the soil hydrological model to hydraulic parameters, water stress, crop yield and lower boundary conditions was assessed after integrating models at one soil column. Free drainage and incremental constant head conditions were implemented in a lower boundary sensitivity analysis. In the second step, to predict Ks over the whole field, the spatial distributions of Ks and its relationship between co-located soil ECa measured by a DUALEM-21S sensor were investigated. Measured groundwater levels and soil layer thickness were interpolated using ordinary point kriging (OK) to a 0.5 by 0.5 m in aim of digital elevation maps. In the third step, a quasi 3D modelling approach was conducted using interpolated data as input hydraulic parameter, geometric information and boundary conditions in the integrated model. In addition, three different irrigation scenarios namely current, no irrigation and optimized irrigations were carried out to find out the most efficient irrigation regime. In this approach, detailed field scale maps of soil water stress, water storage and crop yield were produced at each specific time interval to evaluate the best and most efficient distribution of water using standard gun sprinkler irrigation. The results show that the effect of the position of the groundwater level was dominant in soil-water content prediction and associated water stress. A time-dependent sensitivity analysis of the hydraulic
-
Soil physics and the water management of spatially variable soils
International Nuclear Information System (INIS)
Youngs, E.G.
1983-01-01
The physics of macroscopic soil-water behaviour in inert porous materials has been developed by considering water flow to take place in a continuum. This requires the flow region to consist of an assembly of representative elementary volumes, repeated throughout space and small compared with the scale of observations. Soil-water behaviour in swelling soils may also be considered as a continuum phenomenon so long as the soil is saturated and swells and shrinks in the normal range. Macroscale heterogeneity superimposed on the inherent microscale heterogeneity can take many forms and may pose difficulties in the definition and measurement of soil physical properties and also in the development and use of predictive theories of soil-water behaviour. Thus, measurement techniques appropriate for uniform soils are often inappropriate, and criteria for soil-water management, obtained from theoretical considerations of behaviour in equivalent uniform soils, are not applicable without modification when there is soil heterogeneity. The spatial variability of soil-water properties is shown in results from field experiments concerned with water flow measurements; these illustrate both stochastic and deterministic heterogeneity in soil-water properties. Problems of water management of spatially variable soils when there is stochastic heterogeneity appear to present an insuperable problem in the application of theory. However, for soils showing deterministic heterogeneity, soil-water theory has been used in the solution of soil-water management problems. Thus, scaling using similar media theory has been applied to the infiltration of water into soils that vary over a catchment area. Also, the drain spacing to control the water-table height in soils in which the hydraulic conductivity varies with depth has been calculated using groundwater seepage theory. (author)
-
Directory of Open Access Journals (Sweden)
Firoz Ahmad
2017-08-01
Full Text Available Changing patterns of land use and land cover have exploited the natural resources. Soil, water and forests are degraded, both quantitatively and qualitatively. Deforestation in recent years has led to changes in the environment and more of soil erosion and loss of potable water. In order to conserve and sustainably use soil and water, a watershed management approach is necessary. It helps in restoring water by increasing the infiltration and reducing the erosion of soil. Such measures should be propagated in rainfall deficit areas. The present study has attempted to study the upper watershed part of Subarnarekha basin in Jharkhand state of India. Remote sensing satellite data (Landsat 8 OLI/TIRS 2013 was used for delineation of the land use/land cover and vegetation index maps. Several thematic layers like slope, drainage and rainfall were integrated to achieve a priority area map using spatial multicriteria decision making. It delineated high medium and low priority areas within the watershed for soil and water conservation. The high priority area was 16.63% of the total study area. Further, the causes were analysed and conservation measures proposed.
-
A comparison of soil moisture relations between standing and ...
African Journals Online (AJOL)
Drainage rates through the profile were established using time domain reflectometry probes while water drainage volumes were assessed using shallow plate lysimeters. Despite slow growth in the unfelled crop during the monitoring period (attributed to a pest infestation), soil moisture depletion remained rapid and ...
-
Comprehensive nitrogen budgets for controlled tile drainage fields in eastern ontario, Canada.
Sunohara, M D; Craiovan, E; Topp, E; Gottschall, N; Drury, C F; Lapen, D R
2014-03-01
Excessive N loading from subsurface tile drainage has been linked to water quality degradation. Controlled tile drainage (CTD) has the potential to reduce N losses via tile drainage and boost crop yields. While CTD can reduce N loss from tile drainage, it may increase losses through other pathways. A multiple-year field-scale accounting of major N inputs and outputs during the cropping season was conducted on freely drained and controlled tile drained agricultural fields under corn ( L.)-soybean [ (L.) Merr.] production systems in eastern Ontario, Canada. Greater predicted gaseous N emissions for corn and soybean and greater observed lateral seepage N losses were observed for corn and soybean fields under CTD relative to free-draining fields. However, observed N losses from tile were significantly lower for CTD fields, in relation to freely drained fields. Changes in residual soil N were essentially equivalent between drainage treatments, while mass balance residual terms were systematically negative (slightly more so for CTD). Increases in plant N uptake associated with CTD were observed, probably resulting in higher grain yields for corn and soybean. This study illustrates the benefits of CTD in decreasing subsurface tile drainage N losses and boosting crop yields, while demonstrating the potential for CTD to increase N losses via other pathways related to gaseous emissions and groundwater seepage. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.
-
Reducing phosphorus loading of surface water using iron-coated sand
Groenenberg, J.E.; Chardon, W.J.; Koopmans, G.F.
2013-01-01
Phosphorus losses from agricultural soils is an important source of P in surface waters leading to surface water quality impairment. In addition to reducing P inputs, mitigation measures are needed to reduce P enrichment of surface waters. Because drainage of agricultural land by pipe drainage is an
-
Soil and periphyton indicators of anthropogenic water-quality changes in a rainfall-driven wetland
McCormick, P.V.
2011-01-01
Surface soils and periphyton communities were sampled across an oligotrophic, soft-water wetland to document changes associated with pulsed inputs of nutrient- and mineral-rich canal drainage waters. A gradient of canal-water influence was indicated by the surface-water specific conductance, which ranged between 743 and 963 ??S cm-1 in the canals to as low as 60 ??S cm-1 in the rainfall-driven wetland interior. Changes in soil chemistry and periphyton taxonomic composition across this gradient were described using piecewise regressions models. The greatest increase in soil phosphorus (P) concentration occurred at sites closest to the canal while soil mineral (sulfur, calcium) concentrations increased most rapidly at the lower end of the gradient. Multiple periphyton shifts occurred at the lower end of the gradient and included; (1) a decline in desmids and non-desmid filamentous chlorophytes, and their replacement by a diatom-dominated community; (2) the loss of soft-water diatom indicator species and their replacement by hard-water species. Increased dominance by cyanobacteria and eutrophic diatom indicators occurred closer to the canals. Soil and periphyton changes indicated four zones of increasing canal influence across the wetland: (1) a zone of increasing mineral concentrations where soft-water taxa remained dominant; (2) a transition towards hard-water, oligotrophic diatoms as mineral concentrations increased further; (3) a zone of dominance by these hard-water species; (4) a zone of rapidly increasing P concentrations and dominance by eutrophic taxa. In contrast to conclusions drawn from routine water-chemistry monitoring, measures of chemical and biological change presented here indicate that most of this rainfall-driven peatland receives some influence from canal discharges. These changes are multifaceted and induced by shifts in multiple chemical constituents. ?? 2010 US Government.
-
Assessment the effect of homogenized soil on soil hydraulic properties and soil water transport
Mohawesh, O.; Janssen, M.; Maaitah, O.; Lennartz, B.
2017-09-01
Soil hydraulic properties play a crucial role in simulating water flow and contaminant transport. Soil hydraulic properties are commonly measured using homogenized soil samples. However, soil structure has a significant effect on the soil ability to retain and to conduct water, particularly in aggregated soils. In order to determine the effect of soil homogenization on soil hydraulic properties and soil water transport, undisturbed soil samples were carefully collected. Five different soil structures were identified: Angular-blocky, Crumble, Angular-blocky (different soil texture), Granular, and subangular-blocky. The soil hydraulic properties were determined for undisturbed and homogenized soil samples for each soil structure. The soil hydraulic properties were used to model soil water transport using HYDRUS-1D.The homogenized soil samples showed a significant increase in wide pores (wCP) and a decrease in narrow pores (nCP). The wCP increased by 95.6, 141.2, 391.6, 3.9, 261.3%, and nCP decreased by 69.5, 10.5, 33.8, 72.7, and 39.3% for homogenized soil samples compared to undisturbed soil samples. The soil water retention curves exhibited a significant decrease in water holding capacity for homogenized soil samples compared with the undisturbed soil samples. The homogenized soil samples showed also a decrease in soil hydraulic conductivity. The simulated results showed that water movement and distribution were affected by soil homogenizing. Moreover, soil homogenizing affected soil hydraulic properties and soil water transport. However, field studies are being needed to find the effect of these differences on water, chemical, and pollutant transport under several scenarios.
-
Colin B. Fuss; Charles T. Driscoll; John L. Campbell
2015-01-01
Atmospheric acid deposition of sulfate and nitrate has declined markedly in the northeastern United States due to emissions controls. We investigated long-term trends in soil water (1984â2011) and stream water (1982â2011) chemistry along an elevation gradient of a forested watershed to evaluate the progress of recovery of drainage waters from acidic deposition at the...
-
Murugappan, A.; Manoharan, A.; Senthilkumar, G.; Krishnamurthy, J.
2017-07-01
Irrigated farming depends on an ample supply of water compatible quality. Presently, a lot of irrigation projects have to depend on inferior quality and not so enviable sources of water supply. In order to prevent troubles during usage of such water supplies of poor quality, there must be meticulous preparation to ensure that the water available with such quality characteristics is put to best use. The effect of water quality upon soil and crops must be better understood in choosing fitting options to manage with impending water quality associated troubles that might decrease soil and crop productivity under existing circumstances of water use. Two tanks (small sized reservoirs) namely, Walajah Tank and Perumal Tank in Cuddalore District, used for irrigation, receive mine drainage water pumped out continuously from the open cast lignite mines of the NLC India Limited, Neyveli, Tamilnadu State. This water has been used by the farmers in the irrigated commands of both Walajah Tank and Perumal Tank for more than three decades. Recently, the beneficiaries had raised fears on the quality of mine drainage waters they had been using for raising crops in the commands of both the tanks. They opined that the coal dust laden mine water used for irrigation had affected the crop yields. This incited us to take up a study to (i) assess the status of quality of surface waters released from the two tanks for irrigation in the respective command areas and (ii) assess the likely impacts of quality of water on soil and on growth and productivity of crops cultivated in the command areas. Further to the technical evaluation of the impacts, a structured questionnaire survey was also conducted among the farmers and the common public in the study area. The findings of the survey confirmed with the outcome of the technical assessment in that the mine drainage had a poor impact in the cultivable command area of Walajah tank system while such impacts were less significant in most parts of
-
Rusu, Dr.; Gus, Dr.; Bogdan, Dr.; Moraru, Dr.; Pop, Dr.; Clapa, Dr.; Pop, Drd.
2009-04-01
The energetic function of the soil expressed through the potential energy accumulated through humus, the biogeochemical function (the circuit of the nutrient elements) are significantly influenced by its hydrophysical function and especially by the state of the bedding- consolidation, soil capacity of retaining an optimal quantity of water, and then its gradual disponibility for plant consumption. The understanding of soil functions and management including nutrient production, stocking, filtering and transforming minerals, water , organic matter , gas circuit and furnishing breeding material, all make the basis of human activity, Earth's past, present and especially future. The minimum tillage soil systems - paraplow, chisel or rotary grape - are polyvalent alternatives for basic preparation, germination bed preparation and sowing, for fields and crops with moderate loose requirements being optimized technologies for: soil natural fertility activation and rationalization, reduction of erosion, increasing the accumulation capacity for water and realization of sowing in the optimal period. By continuously applying for 10 years the minimum tillage system in a crop rotation: corn - soy-bean - wheat - potato / rape, an improvement in physical, hydro-physical and biological properties of soil was observed, together with the rebuilt of structure and increase of water permeability of soil. The minimum tillage systems ensure an adequate aerial-hydrical regime for the biological activity intensity and for the nutrients solubility equilibrium. The vegetal material remaining at the soil surface or superficially incorporated has its contribution to intensifying the biological activity, being an important resource of organic matter. The minimum tillage systems rebuild the soil structure, improving the global drainage of soil which allows a rapid infiltration of water in soil. The result is a more productive soil, better protected against wind and water erosion and needing less
-
Tile drainage discharge from managed turf is known to carry elevated concentrations of agronomic fertilizers and chemicals. One approach being considered to reduce the transport is end-of-tile-filters. Laboratory and field studies have been initiated to address the efficacy of this approach. Result...
-
Transport assessment - arid: measurement and prediction of water movement below the root zone
International Nuclear Information System (INIS)
Gee, G.W.; Kirkham, R.R.
1984-09-01
The amount of water transported below the root-zone and available for drainage (recharge) must be known in order to quantify the potential for leaching at low-level waste sites. Under arid site conditions, we quantified drainage by using weighing lysimeters containing sandy soil and measured 6 and 11 cm of drainage for a 1-yr period (June 1983-May 1984) from grass-covered and bare-soil surfaces, respectively. Precipitation during this period at our test site near Richland, Washington, was 25 cm. Similar drainage values were estimated from neutron probe measurements of water content profile changes in an adjacent grass-covered site. These data suggest that significant amounts of drainage can occur at arid sites when soils are coarse textured and precipitation occurs during fall and winter months. Model simulations predicted drainage values comparable to those measured with our weighing lysimeters. Long-term, 500- to 1000-yr predictions of leaching are possible with our model simulations. However, additional studies are needed to evaluate the effect of soil variability and stochastic rainfall inputs on drainage estimates, particularly for arid sites. 15 references, 9 figures, 1 table
-
Influence of mine drainage on water quality along River Nyaba in ...
African Journals Online (AJOL)
ELO
Okpara coal mine in Enugu southeastern Nigeria to investigate the influence of mine drainage on the ... and wet seasons are above levels recommended by WHO for drinking water and other domestic ...... mineralogy and mineral processing.
-
Directory of Open Access Journals (Sweden)
Meng-hua Xiao
2013-04-01
Full Text Available While many controlled irrigation and drainage techniques have been adopted in China, the environmental effects of these techniques require further investigation. This study was conducted to examine the changes of nitrogen and phosphorus of a flooded paddy water system after fertilizer application and at each growth stage so as to obtain the optimal drainage time at each growth stage. Four treatments with different water level management methods at each growth stage were conducted under the condition of ten-day continuous flooding. Results show that the ammonia nitrogen (NH+4-N concentration reached the peak value once the fertilizer was applied, and then decreased to a relatively low level seven to ten days later, and that the nitrate nitrogen (NO-3-N concentration gradually rose to its peak value, which appeared later in subsurface water than in surface water. Continuous flooding could effectively reduce the concentrations of NH+4-N, NO-3-N , and total phosphorus (TP in surface water. However, the paddy water disturbance, in the process of soil surface adsorption and nitrification, caused NH+4-N to be released and increased the concentrations of NH+4-N and NO-3-N in surface water. A multi-objective controlled drainage model based on environmental factors was established in order to obtain the optimal drainage time at each growth stage and better guide the drainage practices of farmers. The optimal times for surface drainage are the fourth, sixth, fifth, and sixth days after flooding at the tillering, jointing-booting, heading-flowering, and milking stages, respectively.
-
Directory of Open Access Journals (Sweden)
Mahmoud Nasr
2015-03-01
Full Text Available Objective: To demonstrate the technical feasibility of the reuse of agricultural drainage water for irrigation. Methods: The agricultural drainage water near Banjar El-Sokar, Borg El-Arab City, Alexandria, Egypt was collected. The measured heavy metals in the drainage water were compared with the permissible levels stated in environmental regulations, Law No. 48 of 1982 concerning the protection of the Nile River and waterways from pollution. Results: Heavy metals and trace elements were detected in this agricultural drainage water as following: Al (1.64 mg/L, Ca (175.00 mg/L, Cd (1.87 mg/L, Co (2.23 mg/L, Cu (1.71 mg/L, Fe (1.64 mg/L, K (20.50 mg/L, and Pb (2.81 mg/L. According to allowable limits, item such as Fe is lower than permissible level of 3.00 mg/L, while Pb and Cu are higher than 0.10 mg/L and 1.00 mg/L, respectively. Conclusions: Vegetables irrigated with such drainage water are not safe for human and animal consumption. Accordingly, the study suggests and recommeds remediation of drainage water using physical, chemical and/or biological methods.
-
Variations in water balance and recharge potential at three western desert sites
International Nuclear Information System (INIS)
Gee, G.W.; Fayer, M.J.; Rockhold, M.L.; Wierenga, P.J.; Young, M.H.; Andraski, B.J.
1994-01-01
Radioactive and hazardous waste landfills exist at numerous desert locations in the USA. At these locations, annual precipitation is low and soils are generally dry, yet little is known about recharge of water and transport of contaminants to the water table. Recent water balance measurements made at three desert locations, Las Cruces, NM, Beatty, NV, and the U.S. Department of Energy's Hanford Site in the state of Washington, provide information on recharge potential under three distinctly different climate and soil conditions. All three sites show water storage increases with time when soils are coarse textured and plants are removed from the surface, the rate of increase being influenced by climatic variables such as precipitation, radiation, temperature, and wind. Lysimeter data from Hanford and Las Cruces indicate that deep drainage (recharge) from bare, sandy soils can range from 10 to > 50% of the annual precipitation. At Hanford, when desert plants are present on sandy or gravelly surface soils, deep drainage is reduced but not eliminated. When surface soils are silt loams, deep drainage is eliminated whether plants are present or not. At Las Cruces and Beatty, the presence of plants eliminated deep drainage at the measurement sites. Differences in water balance between sites are attributed to precipitation quantity and distribution and to soil and vegetation types. The implication of waste management at desert locations is that surface soil properties and plant characteristics must be considered in waste site design in order to minimize recharge potential. 39 refs., 9 figs., 3 tabs
-
Directory of Open Access Journals (Sweden)
M. Göckede
2017-12-01
Full Text Available Hydrologic conditions are a key factor in Arctic ecosystems, with strong influences on ecosystem structure and related effects on biogeophysical and biogeochemical processes. With systematic changes in water availability expected for large parts of the northern high-latitude region in the coming centuries, knowledge on shifts in ecosystem functionality triggered by altered water levels is crucial for reducing uncertainties in climate change predictions. Here, we present findings from paired ecosystem observations in northeast Siberia comprising a drained and a control site. At the drainage site, the water table has been artificially lowered by up to 30 cm in summer for more than a decade. This sustained primary disturbance in hydrologic conditions has triggered a suite of secondary shifts in ecosystem properties, including vegetation community structure, snow cover dynamics, and radiation budget, all of which influence the net effects of drainage. Reduced thermal conductivity in dry organic soils was identified as the dominating drainage effect on energy budget and soil thermal regime. Through this effect, reduced heat transfer into deeper soil layers leads to shallower thaw depths, initially leading to a stabilization of organic permafrost soils, while the long-term effects on permafrost temperature trends still need to be assessed. At the same time, more energy is transferred back into the atmosphere as sensible heat in the drained area, which may trigger a warming of the lower atmospheric surface layer.
-
Đurović Nevenka; Stričević Ružica
2004-01-01
This article represents data of the drainage system functioning at the experimental field "Radmilovac" just after its construction and eleven years later. In the first three years of the system functioning the values of drainage discharge, water table depth and soil moisture content were in the range which characterizes satisfactorily drained soil. The absence of weed control and luxinate growth of annual and perennial weed every year canal silting, solid waste disposal in the canal significa...
-
Sofia, Giulia; Pizzulli, Federica; Tarolli, Paolo
2017-04-01
Agriculture and land-use management has changed drastically in Italy since the end of the Second World War, driven by local but also European agricultural policies. As a result of these changes in farming practices and land use, many drainage networks have changed producing a greater exposure to flooding with a broad range of impacts on society, also because of climate inputs coupling with the human drivers. This study focuses on two main points: which kind of land use and farming changes have been observed in the most recent years ( 30 years)? How do these changes interact with climate and soil conditions? An open challenge to understand how these changes influence the watershed response, is, in fact, to understand if rainfall characteristics and climate have a synergistic effect, if their interaction matters, or to understand what element has the greatest influence on the watershed response connected to agricultural changes. The work is based on a simple model of water infiltration due to soil properties, and a connected evaluation of the distributed surface water storage offered by artificial drainage networks in a study area in Veneto (north-eastern Italy). The analysis shows that economic changes control the development of agro-industrial landscapes, with effects on the hydrological response. However, these changes deeply interact with antecedent soil conditions and climate characteristics. Intense and irregular rainfall events and events with a high recurrence should be expected to be the most critical. The presented outcomes highlight the importance of understanding how agricultural practices can be the driver of or can be used to avoid, or at least mitigate, flooding. The proposed methods can be valuable tools in evaluating the costs and benefits of the management of water in agriculture to inform better policy decision-making. References Sofia G, Tarolli P. 2017. Hydrological Response to 30 years of Agricultural Surface Water Management. Land 6 (1): 3 DOI
-
Hydrological balance and water transport processes of partially sealed soils
Timm, Anne; Wessolek, Gerd
2017-04-01
With increased urbanisation, soil sealing and its drastic effects on hydrological processes have received a lot of attention. Based on safety concerns, there has been a clear focus on urban drainage and prevention of urban floods caused by storm water events. For this reason, any kind of sealing is often seen as impermeable runoff generator that prevents infiltration and evaporation. While many hydrological models, especially storm water models, have been developed, there are only a handful of empirical studies actually measuring the hydrological balance of (partially) sealed surfaces. These challenge the general assumption of negligible infiltration and evaporation and show that these processes take place even for severe sealing such as asphalt. Depending on the material, infiltration from partially sealed surfaces can be equal to that of vegetated ones. Therefore, more detailed knowledge is needed to improve our understanding and models. In Berlin, two partially sealed weighable lysimeters were equipped with multiple temperature and soil moisture sensors in order to study their hydrological balance, as well as water and heat transport processes within the soil profile. This combination of methods affirms previous observations and offers new insights into altered hydrological processes of partially sealed surfaces at a small temporal scale. It could be verified that not all precipitation is transformed into runoff. Even for a relatively high sealing degree of concrete slabs with narrow seams, evaporation and infiltration may exceed runoff. Due to the lack of plant roots, the hydrological balance is mostly governed by precipitation events and evaporation generally occurs directly after rainfall. However, both surfaces allow for upward water transport from the upper underlying soil layers, sometimes resulting in relatively low evaporation rates on days without precipitation. The individual response of the surfaces differs considerably, which illustrates how
-
Water repellent soils: the case for unsaturated soil mechanics
Directory of Open Access Journals (Sweden)
Beckett Christopher
2016-01-01
Full Text Available Water repellent (or “hydrophobic” or “non-wetting” soils have been studied by soil scientists for well over a century. These soils are typified by poor water infiltration, which leads to increased soil erosion and poor crop growth. However, the importance of water repellence on determining soil properties is now becoming recognised by geotechnical engineers. Water repellent soils may, for example, offer novel solutions for the design of cover systems overlying municipal or mine waste storage facilities. However, investigations into factors affecting their mechanical properties have only recently been initiated. This purpose of this paper is to introduce geotechnical engineers to the concept of water repellent soils and to discuss how their properties can be evaluated under an unsaturated soils framework. Scenarios in which water repellent properties might be relevant in geotechnical applications are presented and methods to quantify these properties in the laboratory and in the field examined.
-
Simpson, Stuart L; Vardanega, Christopher R; Jarolimek, Chad; Jolley, Dianne F; Angel, Brad M; Mosley, Luke M
2014-05-01
The discharge of acid drainage from the farm irrigation areas to the Murray River in South Australia represents a potential risk to water quality. The drainage waters have low pH (2.9-5.7), high acidity (up to 1190 mg L(-1) CaCO3), high dissolved organic carbon (10-40 mg L(-1)), and high dissolved Al, Co, Ni and Zn (up to 55, 1.25, 1.30 and 1.10 mg L(-1), respectively) that represent the greatest concern relative to water quality guidelines (WQGs). To provide information on bioavailability, changes in metal speciation were assessed during mixing experiments using filtration (colloidal metals) and Chelex-lability (free metal ions and weak inorganic metal complexes) methods. Following mixing of drainage and river water, much of the dissolved aluminium and iron precipitated. The concentrations of other metals generally decreased conservatively in proportion to the dilution initially, but longer mixing periods caused increased precipitation or adsorption to particulate phases. Dissolved Co, Mn and Zn were typically 95-100% present in Chelex-labile forms, whereas 40-70% of the dissolved nickel was Chelex-labile and the remaining non-labile fraction of dissolved nickel was associated with fine colloids or complexed by organic ligands that increased with time. Despite the different kinetics of precipitation, adsorption and complexation reactions, the dissolved metal concentrations were generally highly correlated for the pooled data sets, indicating that the major factors controlling the concentrations were similar for each metal (pH, dilution, and time following mixing). For dilutions of the drainage waters of less than 1% with Murray River water, none of the metals should exceed the WQGs. However, the high concentrations of metals associated with fine precipitates within the receiving waters may represent a risk to some aquatic organisms. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.
-
Contribution to the study of pollution of soil and water in Oued El Maleh area (Mohammedia, Morocco)
El hajjaji, Souad; Dahchour, Abdelmalek; Belhsaien, Kamal; Zouahri, Abdelmjid; Moussadek, Rachid; Douaik, Ahmed
2016-04-01
In Morocco, diffuse ground and surface water pollution in irrigated areas has caused an increase in the risk of water and soil quality deterioration. This has generated a health and environmental risks. The present study was carried out in the Oued El Maleh region located 65 Km to the south of Rabat on the Moroccan Atlantic coast. It covers a surface area of 310 km2 where agriculture constitutes the main activity of the population. This region is considered as a very important agricultural area, known nationally for its high potential for market gardening. This intensification has been accompanied by an excessive use of agrochemical inputs and poor control of irrigation and drainage. Consequently, salinization phenomena and deterioration of soil structure as well as water are about to create an alarming situation. In order to assess the state of pollution of waters and soil in the region, our study focuses on the determination of physicochemical parameters for the quality of water and soil. The obtained results from sampled wells and surface water show relatively higher values of nitrate and conductivity exceeding Moroccan national standards and revealing net degradation of water quality; therefore the water can be considered not suitable for human consumption and can induce a degradation of soil. The results of the studied soil show that the pH of these soils is weakly to moderately basic; they are usually non-saline with organic matter content moderately filled. Moreover, very high concentrations of nutrients (potassium, phosphorus and nitrogen) were recorded, highlighting poor management fertilizing vegetable crops in the region of Oued El Maleh.
-
Directory of Open Access Journals (Sweden)
Barry J. Allred
2017-10-01
Full Text Available Filter treatment may be a viable means for removing the nitrate (NO3−, phosphate (PO43−, and pesticides discharged with agricultural drainage waters that cause adverse environmental impacts within the U.S. on local, regional, and national scales. Laboratory batch test screening for agricultural drainage water treatment potential was conducted on 58 industrial product/byproduct filter materials grouped into six categories: (1 high carbon content media; (2 high iron content media; (3 high aluminum content media; (4 surfactant modified clay/zeolite; (5 coal combustion residuals; and (6 spent foundry sands. Based on a percent contaminant removal criteria of 75% or greater, seven industrial products/byproducts were found to meet this standard for NO3− alone, 44 met this standard for PO43−, and 25 met this standard for the chlorinated triazine herbicide, atrazine. Using a 50% or greater contaminant removal criteria, five of the industrial product/byproduct filter materials exhibited potential for removing NO3−, PO43−, and atrazine together; eight showed capability for combined NO3− and PO43− removal; 21 showed capability for combined PO43− and atrazine removal; and nine showed capability for combined NO3− and atrazine removal. The results of this study delineated some potential industrial product/byproduct filter materials for drainage water treatment; however, a complete feasibility evaluation for drainage water treatment of any of these filter materials will require much more extensive testing.
-
Directory of Open Access Journals (Sweden)
Raymond Tojo Radimy
2013-01-01
Full Text Available The French Atlantic marshlands, reclaimed since the Middle Age, have been successively used for extensive grazing and more recently for cereal cultivation from 1970. The soils have acquired specific properties which have been induced by the successive reclaiming and drainage works and by the response of the clay dominant primary sediments, that is, structure, moisture, and salinity profiles. Based on the whole survey of the Marais Poitevin and Marais de Rochefort and in order to explain the mechanisms of marsh soil behavior, the work focuses on two typical spots: an undrained grassland since at least 1964 and a drained cereal cultivated field. The structure-hydromechanical profiles relationships have been established thanks to the clay matrix shrinkage curve. They are confronted to the hydraulic functioning including the fresh-to-salt water transfers and to the recording of tensiometer profiles. The CE1/5 profiles supply the water geochemical and geophysical data by their better accuracy. Associated to the available water capacity calculation they allow the representation of the parallel evolution of the residual available water capacity profiles and salinity profiles according to the plant growing and rooting from the mesophile systems of grassland to the hygrophile systems of drained fields.
-
Directory of Open Access Journals (Sweden)
Amal A. Othman
2012-04-01
Full Text Available More than 12 × 109 m3/year of Nile Delta drainage water is annually discharged into the Mediterranean Sea. El-Salam (peace canal, having a mixture of such drainage water and the Nile water (1:1 ratio, crosses the Suez canal eastward to the deserts of north Sinai. The suitability of the canal water for agriculture is reported here. Representative samples were obtained during two successive years to follow effects of seasonal and spatial distribution, along the first 55 km course in north Sinai, on the water load of total bacteria, bacterial indicators of pollution, and chemical and heavy metals contents. In general, the canal water is acceptable for irrigation, with much concern directed towards the chemical contents of total salts (EC, Na and K, as well as the trace elements Cd and Fe. Extending the canal course further than 30 km significantly lowered the fecal pollution rate to the permissible levels of drinking water. Results strongly emphasize the need for effective pre-treatment of the used drainage water resources prior mixing with the Nile water.
-
Preventive measures of water hammer in the design stage of mine drainage system
International Nuclear Information System (INIS)
Wu Dongyan
2012-01-01
The mechanisms and types of water hammer accident in mine drainage system are introduced. Through calculating water hammer pressure head of pump-failure water hammer, the extent of the harm caused by water hammer can be displayed visually, therefore,the preventive measures to be taken in the design stage are put forward in order to reduce water hammer accident. (author)
-
Timms, W. A.; Young, R. R.; Huth, N.
2012-04-01
The magnitude and timing of deep drainage and salt leaching through clay soils is a critical issue for dryland agriculture in semi-arid regions (2000 mm yr-1) such as parts of Australia's Murray-Darling Basin (MDB). In this rare study, hydrogeological measurements and estimations of the historic water balance of crops grown on overlying Grey Vertosols were combined to estimate the contribution of deep drainage below crop roots to recharge and salinization of shallow groundwater. Soil sampling at two sites on the alluvial flood plain of the Lower Namoi catchment revealed significant peaks in chloride concentrations at 0.8-1.2 m depth under perennial vegetation and at 2.0-2.5 m depth under continuous cropping indicating deep drainage and salt leaching since conversion to cropping. Total salt loads of 91-229 t ha-1 NaCl equivalent were measured for perennial vegetation and cropping, with salinity to ≥ 10 m depth that was not detected by shallow soil surveys. Groundwater salinity varied spatially from 910 to 2430 mS m-1 at 21 to 37 m depth (N = 5), whereas deeper groundwater was less saline (290 mS m-1) with use restricted to livestock and rural domestic supplies in this area. The Agricultural Production Systems Simulator (APSIM) software package predicted deep drainage of 3.3-9.5 mm yr-1 (0.7-2.1% rainfall) based on site records of grain yields, rainfall, salt leaching and soil properties. Predicted deep drainage was highly episodic, dependent on rainfall and antecedent soil water content, and over a 39 yr period was restricted mainly to the record wet winter of 1998. During the study period, groundwater levels were unresponsive to major rainfall events (70 and 190 mm total), and most piezometers at about 18 m depth remained dry. In this area, at this time, recharge appears to be negligible due to low rainfall and large potential evapotranspiration, transient hydrological conditions after changes in land use and a thick clay dominated vadose zone. This is in
-
Gutekunst, Madison Y; Vargas, Rodrigo; Seyfferth, Angelia L
2017-09-01
Incorporation of silica-rich rice husk residue into flooded paddy soil decreases arsenic uptake by rice. However, the impact of this practice on soil greenhouse gas (GHG) emissions and elemental cycling is unresolved particularly as amended soils experience recurrent flooding and drying cycles. We evaluated the impact of pre-incubated silica-rich rice residue incorporation to soils on pore water chemistry and soil GHG fluxes (i.e., CO 2 , CH 4 , N 2 O) over a flooding and drying cycle typical of flooded rice cultivation. Soils pre-incubated with rice husk had 4-fold higher pore water Si than control and 2-fold higher than soils pre-incubated with rice straw, whereas the pore water As and Fe concentrations in soils amended with pre-incubated straw and husk were unexpectedly similar (maximum ~0.85μM and ~450μM levels, respectively). Pre-incubation of residues did not affect Si but did affect the pore water levels of As and Fe compared to previous studies using fresh residues where straw amended soils had higher As and Fe in pore water. The global warming potential (GWP) of soil GHG emissions decreased in the order straw (612±76g CO 2 -eqm -2 )>husk (367±42gCO 2 -eqm -2 )>ashed husk=ashed straw (251±26 and 278±28gCO 2 -eqm -2 )>control (186±23gCO 2 -eqm -2 ). The GWP increase due to pre-incubated straw amendment was due to: a) larger N 2 O fluxes during re-flooding; b) smaller contributions from larger CH 4 fluxes during flooded periods; and c) higher CH 4 and CO 2 fluxes at the onset of drainage. In contrast, the GWP of the husk amendment was dominated by CO 2 and CH 4 emissions during flooded and drainage periods, while ashed amendments increased CO 2 emissions particularly during drainage. This experiment shows that ashed residues and husk addition minimizes GWP of flooded soils and enhances pore water Si compared to straw addition even after pre-incubation. Copyright © 2017 Elsevier B.V. All rights reserved.
-
Directory of Open Access Journals (Sweden)
Gogina Elena
2016-01-01
Full Text Available The article deals with innovative methods, technologies and materials intended to reduce the adverse ecological impact of human waste and various industrial waste situated in municipal solid waste landfills (MSW, on water bodies, soil, and atmosphere. The existence of these factors makes the region less attractive for urban development. A comparison has been made of the methods intended to reduce the damage caused to the environment, in order to provide for sustainable development of cities, using the example of an actual landfill situated in the territory of Moscow. A scheme of reconstruction is recommended for the drainage water treatment plant at this landfill, which will lead to improvement of the environmental situation and contribute to the development of territories in the adjacent districts, and to reduction of pollution load on the river and atmosphere.
-
The Influence of Soil Particle on Soil Condensation Water
Hou Xinwei; Chen Hao; Li Xiangquan; Cui Xiaomei; Liu Lingxia; Wang Zhenxing
2013-01-01
The experiment results showed that the indoor experiment formed from the volume of soil hygroscopic water increased gradually with decreasing size of soil particles. In the outdoor experiments, the results showed that the formed condensation water in medium sand was greater than it was in fine sand; the soil hot condensation water was mainly formed in the top layer of soil between 0-5 cm. We also found that covering the soil surface with stones can increase the volume of formed soil condensat...
-
Sequestration of phosphorus by acid mine drainage floc
Adler, P.R.; Sibrell, P.L.
2003-01-01
Solubilization and transport of phosphorus (P) to the water environment is a critical environmental issue. Flocs resulting from neutralizing acid mine drainage (AMD) were tested as a possible lowcost amendment to reduce the loss of soluble P from agricultural fields and animal wastewater. Flocs were prepared by neutralizing natural and synthetic solutions of AMD with limestone, lime, ammonium hydroxide, and sodium hydroxide. Phosphorus sequestration was tested in three distinct environments: water, soil, and manure storage basins. In water, flocs prepared from AMD adsorbed 10 to 20 g P kg-1 dry floc in equilibrium with 1 mg L-1 soluble P. Similar results were observed for both Fe-based and A1-based synthetic flocs. A local soil sample adsorbed about 0.1 g P kg-1, about two orders of magnitude less. The AMD-derived flocs were mixed with a highP soil at 5 to 80 g floc kg-1 soil, followed by water and acid (Mehlich1) extractions. All flocs performed similarly. About 70% of the waterextractable P was sequestered by the floc when applied at a rate of 20 g floc kg-1 soil, whereas plant-available P only decreased by about 30%. Under anaerobic conditions simulating manure storage basins, all AMD flocs reduced soluble P by greater than 95% at a rate of 0.2 g floc g-1 rainbow trout (Oncorhynchus mykiss) manure. These findings indicate that AMD flocs could be an effective agent for preventing soluble P losses from soil and manure to the water environment, while at the same time decreasing the costs associated with AMD treatment.
-
Bradley, Michael W.; Worland, Scott C.
2015-01-01
Acid-rock drainage occurs through the interaction of rainfall on pyrite-bearing formations. When pyrite (FeS2) is exposed to oxygen and water in mine workings or roadcuts, the mineral decomposes and sulfur may react to form sulfuric acid, which often results in environmental problems and potential damage to the transportation infrastructure. The accelerated oxidation of pyrite and other sulfidic minerals generates low pH water with potentially high concentrations of trace metals. Much attention has been given to contamination arising from acid mine drainage, but studies related to acid-rock drainage from road construction are relatively limited. The U.S. Geological Survey, in cooperation with the Tennessee Department of Transportation, is conducting an investigation to evaluate the occurrence and processes controlling acid-rock drainage and contaminant transport from roadcuts in Tennessee. The basic components of acid-rock drainage resulting from transportation activities are described and a bibliography, organized by relevant categories (remediation, geochemical, microbial, biological impact, and secondary mineralization) is presented.
-
Arid site water balance: evapotranspiration modeling and measurements
International Nuclear Information System (INIS)
Gee, G.W.; Kirkham, R.R.
1984-09-01
In order to evaluate the magnitude of radionuclide transport at an aird site, a field and modeling study was conducted to measure and predict water movement under vegetated and bare soil conditions. Significant quantities of water were found to move below the roo of a shallow-rooted grass-covered area during wet years at the Hanford site. The unsaturated water flow model, UNSAT-1D, was resonably successful in simulating the transient behavior of the water balance at this site. The effects of layered soils on water balance were demonstrated using the model. Models used to evaluate water balance in arid regions should not rely on annual averages and assume that all precipitation is removed by evapotranspiration. The potential for drainage at arid sites exists under conditions where shallow rooted plants grow on coarse textured soils. This condition was observed at our study site at Hanford. Neutron probe data collected on a cheatgrass community at the Hanford site during a wet year indicated that over 5 cm of water drained below the 3.5-m depth. The unsaturated water flow model, UNSAT-1D, predicted water drainage of about 5 cm (single layer, 10 months) and 3.5 cm (two layers, 12 months) for the same time period. Additional field measurements of hydraulic conductivity will likely improve the drainage estimate made by UNSAT-1D. Additional information describing cheatgrass growth and water use at the grass site could improve model predictions of sink terms and subsequent calculations of water storage within the rooting zone. In arid areas where the major part of the annual precipitation occurs during months with low average potential evapotranspiration and where soils are vegetated but are coarse textured and well drained, significant drainage can occur. 31 references, 18 figures, 1 table
-
Impact of Tile Drainage on the Distribution of Concentration and Age of Inorganic Soil Nitrogen.
Woo, D.; Kumar, P.
2017-12-01
Extensive network of tile drainage network across the Midwestern United States, northern Europe and other regions of the world have enhanced agricultural productivity. Because of its impact on sub-surface flow patterns and moisture and temperature dynamics, it controls the nitrogen cycle in agricultural systems, and its influence on nitrogen dynamics plays a key role in determining the short- and long-term evolution of soil inorganic nitrogen concentration and age. The spatial mapping of nitrogen concentration and age under tile-drained fields has, therefore, the potential to open up novel solution to the vexing challenge of reducing environmental impacts while at the same time maintaining agricultural productivity. The objective of this study is to explore the impacts of tile drains on the age dynamics of nitrate, immobile ammonium, mobile ammonia/um, and non-reactive tracer (such as chloride) by implementing two mobile interacting pore domains to capture matrix and preferential flow paths in a coupled ecohydrology and biogeochemistry model, Dhara. We applied this model to an agricultural farm supporting a corn-soybean rotation in the Midwestern United States. It should be expected that the installation of tile drains decrease the age of soil nutrient due to nutrient losses through tile drainage. However, an increase in the age of mobile ammonia/um is observed in contrast to the cases for nitrate, immobile ammonium, and non-reactive tracer. These results arise because the depletion of mobile ammonia/um due to tile drainage causes a high mobility flux from immobile ammonium to mobile ammonia/um, which also carries a considerable amount of relatively old age of immobile ammonium to mobile ammonia/um. In addition, the ages of nitrate and mobile ammonia/um in tile drainage range from 1 to 3 years, and less than a year, respectively, implying that not considering age transformations between nitrogen species would result in substantial underestimation of nitrogen ages
-
Influence of land improvement on soil oxidation. Inverkan av grundfoerbaettring paa markens syrehalt
Energy Technology Data Exchange (ETDEWEB)
Kowalik, P.J.
1985-01-01
The paper presents the theoretical analysis of influence of the land reclamation on soil oxidation. Examination was carried out on dependencies existing among soil moisture content, respiratory activity of the soil, absolute soil porosity, gas-filled soil porosity, coeffficient of oxygen diffusion in soil air and soil liquid, oxygen concentration in soil air and in soil water, oxygen diffusion flux, oxygen diffusion rate and the depth of zone of aeration in soil profile. Some remarks about the influence of soil oxidation on root growth and morphology of soil profile were presented too. Results of own empirical investigations and similar data from literature verify theoretical ideas pointed out in the paper. The methods and results of own measurements of ODR (oxygen diffusion rate) has been presented in detail. The research explains the relationship between soil moisture content and soil oxidation. As a result of the analysis there have been proposed such methods of land improvement that the water and oxygen demands of plant roots and microorganisms would be satisfying. The paper proposes a new method of account of the so-called anaerobic soil moisture content. This moisture should be the highest for irrigation practice and more or less lowest for drainage of soil water. Soil moisture a little lower than anarobic soil water content is enough for warranting the sufficient soil aeration during drainage and irrigation activity. With 82 refs.
-
Estimation of water percolation by different methods using TDR
Directory of Open Access Journals (Sweden)
Alisson Jadavi Pereira da Silva
2014-02-01
Full Text Available Detailed knowledge on water percolation into the soil in irrigated areas is fundamental for solving problems of drainage, pollution and the recharge of underground aquifers. The aim of this study was to evaluate the percolation estimated by time-domain-reflectometry (TDR in a drainage lysimeter. We used Darcy's law with K(θ functions determined by field and laboratory methods and by the change in water storage in the soil profile at 16 points of moisture measurement at different time intervals. A sandy clay soil was saturated and covered with plastic sheet to prevent evaporation and an internal drainage trial in a drainage lysimeter was installed. The relationship between the observed and estimated percolation values was evaluated by linear regression analysis. The results suggest that percolation in the field or laboratory can be estimated based on continuous monitoring with TDR, and at short time intervals, of the variations in soil water storage. The precision and accuracy of this approach are similar to those of the lysimeter and it has advantages over the other evaluated methods, of which the most relevant are the possibility of estimating percolation in short time intervals and exemption from the predetermination of soil hydraulic properties such as water retention and hydraulic conductivity. The estimates obtained by the Darcy-Buckingham equation for percolation levels using function K(θ predicted by the method of Hillel et al. (1972 provided compatible water percolation estimates with those obtained in the lysimeter at time intervals greater than 1 h. The methods of Libardi et al. (1980, Sisson et al. (1980 and van Genuchten (1980 underestimated water percolation.
-
Performance evaluation of TDT soil water content and watermark soil water potential sensors
This study evaluated the performance of digitized Time Domain Transmissometry (TDT) soil water content sensors (Acclima, Inc., Meridian, ID) and resistance-based soil water potential sensors (Watermark 200, Irrometer Company, Inc., Riverside, CA) in two soils. The evaluation was performed by compar...
-
Development of earthworm burrow systems and the influence of earthworms on soil hydrology
Ligthart, T.N.
1996-01-01
Inoculation of earthworms can help to restore or ameliorate land qualities. Earthworms create burrows and alter the structure of the soil matrix, which influence the water infiltration, drainage, water retention and the aeration of the soil. The way and rate of the development of -
Sustainable Soil Water Management Systems
Basch, G.; Kassam, A.; Friedrich, T.; Santos, F.L.; Gubiani, P.I.; Calegari, A.; Reichert, J.M.; dos Santos, D.R.
2012-01-01
Soil quality and its management must be considered as key elements for an effective management of water resources, given that the hydrological cycle and land management are intimately linked (Bossio et al. 2007). Soil degradation has been described by Bossio et al. (2010) as the starting point of a negative cycle of soil-water relationships, creating a positive, self-accelerating feedback loop with important negative impacts on water cycling and water productivity. Therefore, sustainable soil...
-
Water balance of the Arctic drainage system using GRACE gravimetry products
Frappart, F; Ramillien, G; Famiglietti, JS
2011-01-01
International audience; Land water and snow mass anomalies versus time were computed from the inversion of 50 GRACE geoids (August 2002 to February 2007) from the RL04 GFZ release and used to characterize the hydrology of the Arctic drainage system. GRACE-based time series have been compared to snow water equivalent and snow depth climatologies, and snowfall for validation purpose. Time series of regional averages of water volume were estimated for the 11 largest Peri-Arctic basins. Strong co...
-
International Nuclear Information System (INIS)
Mages, Margarete; Tuempling, Wolf von Jr.; Veen, Andrea van der; Baborowski, Martina
2006-01-01
Human impacts like mining activities lead to higher element concentration in surface waters. For different pollution levels, the consequences for aquatic organisms are not yet investigated in detail. Therefore, the aim of this investigation is to determine the influence of mining affected surface waters on biofilms. Elements like heavy metals can be absorbed on cell walls and on polymeric substances or enter the cytoplasm of the cells. Thus, they are important for the optimization of industrial biotechnological processes and the environmental biotechnology. Beyond this, biofilms can also play an important role in wastewater treatment processes and serve as bioindicators in the aquatic environment. The presented total reflection X-ray fluorescence spectroscopic investigation was performed to compare the element accumulation behavior of biofilms grown on natural or on artificial materials of drainage water affected by former copper mining activities. A high salt and heavy metal pollution is characteristic for the drainage water. For an assessment of these results, samples from stream Schlenze upstream the confluence with the drainage water, a small tributary of the Saale River in central Germany, were analyzed, too
-
Transient drainage summary report
International Nuclear Information System (INIS)
1996-09-01
This report summarizes the history of transient drainage issues on the Uranium Mill Tailings Remedial Action (UMTRA) Project. It defines and describes the UMTRA Project disposal cell transient drainage process and chronicles UMTRA Project treatment of the transient drainage phenomenon. Section 4.0 includes a conceptual cross section of each UMTRA Project disposal site and summarizes design and construction information, the ground water protection strategy, and the potential for transient drainage
-
Difficulties in the evaluation and measuring of soil water infiltration
Pla-Sentís, Ildefonso
2013-04-01
Soil water infiltration is the most important hydrological parameter for the evaluation and diagnosis of the soil water balance and soil moisture regime. Those balances and regimes are the main regulating factors of the on site water supply to plants and other soil organisms and of other important processes like runoff, surface and mass erosion, drainage, etc, affecting sedimentation, flooding, soil and water pollution, water supply for different purposes (population, agriculture, industries, hydroelectricity), etc. Therefore the evaluation and measurement of water infiltration rates has become indispensable for the evaluation and modeling of the previously mentioned processes. Infiltration is one of the most difficult hydrological parameters to evaluate or measure accurately. Although the theoretical aspects of the process of soil water infiltration are well known since the middle of the past century, when several methods and models were already proposed for the evaluation of infiltration, still nowadays such evaluation is not frequently enough accurate for the purposes being used. This is partially due to deficiencies in the methodology being used for measuring infiltration, including some newly proposed methods and equipments, and in the use of non appropriate empirical models and approaches. In this contribution we present an analysis and discussion about the main difficulties found in the evaluation and measurement of soil water infiltration rates, and the more commonly committed errors, based on the past experiences of the author in the evaluation of soil water infiltration in many different soils and land conditions, and in their use for deducing soil water balances under variable and changing climates. It is concluded that there are not models or methods universally applicable to any soil and land condition, and that in many cases the results are significantly influenced by the way we use a particular method or instrument, and by the alterations in the soil
-
Energy Technology Data Exchange (ETDEWEB)
Jones, Adele M.; Xue, Youjia [School of Civil and Environmental Engineering, University of New South Wales, Sydney, NSW 2052 (Australia); Kinsela, Andrew S. [School of Civil and Environmental Engineering, University of New South Wales, Sydney, NSW 2052 (Australia); Institute for Environmental Research (IER), Australian Nuclear Science and Technology Organisation (ANSTO), Lucas Heights, NSW 2234 (Australia); Wilcken, Klaus M. [Institute for Environmental Research (IER), Australian Nuclear Science and Technology Organisation (ANSTO), Lucas Heights, NSW 2234 (Australia); Collins, Richard N., E-mail: richard.collins@unsw.edu.au [School of Civil and Environmental Engineering, University of New South Wales, Sydney, NSW 2052 (Australia)
2016-03-15
Donnan dialysis has been applied to forty filtered drainage waters collected from five coastal lowland acid sulfate soil (CLASS) catchments across north-eastern NSW, Australia. Despite having average pH values < 3.9, 78 and 58% of Al and total Fe, respectively, were present as neutral or negatively-charged species. Complementary isotope dilution experiments with {sup 55}Fe and {sup 26}Al demonstrated that only soluble (i.e. no colloidal) species were present. Trivalent rare earth elements (REEs) were also mainly present (> 70%) as negatively-charged complexes. In contrast, the speciation of the divalent trace metals Co, Mn, Ni and Zn was dominated by positively-charged complexes and was strongly correlated with the alkaline earth metals Ca and Mg. Thermodynamic equilibrium speciation calculations indicated that natural organic matter (NOM) complexes dominated Fe(III) speciation in agreement with that obtained by Donnan dialysis. In the case of Fe(II), however, the free cation was predicted to dominate under thermodynamic equilibrium, whilst our results indicated that Fe(II) was mainly present as neutral or negatively-charged complexes (most likely with sulfate). For all other divalent metals thermodynamic equilibrium speciation calculations agreed well with the Donnan dialysis results. The proportion of Al and REEs predicted to be negatively-charged was also grossly underestimated, relative to the experimental results, highlighting possible inaccuracies in the stability constants developed for these trivalent Me(SO{sub 4}){sub 2}{sup −} and/or Me–NOM complexes and difficulties in modeling complex environmental samples. These results will help improve metal mobility and toxicity models developed for CLASS-affected environments, and also demonstrate that Australian CLASS environments can discharge REEs at concentrations an order of magnitude greater than previously reported. - Highlights: • CLASS discharge large amounts of metals and their speciation is poorly
-
Ensuring safe use of water in a river basin with uranium drainage
International Nuclear Information System (INIS)
Carvalho, F.; Oliveira, J.; Malta, M.
2014-01-01
A regular radioactivity monitoring programme ensures radioactivity surveillance in a river system with multiple and intensive uses of water. In the catchment of River Mondego, centre of Portugal, there is a uranium mining and milling legacy which encompasses about 12 old uranium mine sites and 3 uranium milling sites. This river basin is an important agriculture and cattle growing region with forest areas for paper pulp production. In the catchment of this river there are four dams for electricity production and two main artificial lakes which are water reservoirs to supply drinking water to more than 3 million people, and irrigation water for agriculture including maize and rice production. In the river basin, environmental remediation works were recently implemented especially at the milling tailings and at the major mine sites, which reduced radioactive drainage into the Mondego tributaries and thus into the Mondego river. Mine drainage and seepage from tailings are recuperated and treated in mine water treatment stations. Although, for example, in drainage from milling tailings at Urgeiriça, water may contain high concentrations of dissolved uranium ("2"3"8U), radium ("2"2"6Ra) and polonium ("2"1"0Po) at 35,700±1100, 1084±30, and 700±40 mBq/L, respectively, in the stream receiving discharges of treated water today radionuclide concentrations are orders of magnitude lower. The tributary streams that in the past received untreated mine discharges are today recovering and concentrations decreased to near natural levels. In the artificial lake of Aguieira dam, built on the Mondego River downstream all uranium sites, and where the main capture of water for human consumption is located, radionuclide concentrations were of 9.2±0.3 mBq/L, 17.7±1.9 mBq/L, and 5.3±0.2 mBq/L for uranium ("2"3"8U), radium ("2"2"6Ra) and polonium ("2"1"0Po), respectively. This water has been over the last years consistently in compliance with the EU drinking water quality standards
-
Presser, Theresa S.; Schwarzbach, Steven E.
2008-01-01
The western San Joaquin Valley is one of the most productive farming areas in the United States, but salt-buildup in soils and shallow groundwater aquifers threatens this area?s productivity. Elevated selenium concentrations in soils and groundwater complicate drainage management and salt disposal. In this document, we evaluate constraints on drainage management and implications of various approaches to management considered in: *the San Luis Drainage Feature Re-Evaluation (SLDFRE) Environmental Impact Statement (EIS) (about 5,000 pages of documentation, including supporting technical reports and appendices); *recent conceptual plans put forward by the San Luis Unit (SLU) contractors (i.e., the SLU Plans) (about 6 pages of documentation); *approaches recommended by the San Joaquin Valley Drainage Program (SJVDP) (1990a); and *other U.S. Geological Survey (USGS) models and analysis relevant to the western San Joaquin Valley. The alternatives developed in the SLDFRE EIS and other recently proposed drainage plans (refer to appendix A for details) differ from the strategies proposed by the San Joaquin Valley Drainage Program (1990a). The Bureau of Reclamation (USBR) in March 2007 signed a record of decision for an in-valley disposal option that would retire 194,000 acres of land, build 1,900 acres of evaporation ponds, and develop a treatment system to remove salt and selenium from drainwater. The recently proposed SLU Plans emphasize pumping drainage to the surface, storing approximately 33% in agricultural water re-use areas, treating selenium through biotechnology, enhancing the evaporation of water to concentrate salt, and identifying ultimate storage facilities for the remaining approximately 67% of waste selenium and salt. The treatment sequence of reuse, reverse osmosis, selenium bio-treatment, and enhanced solar evaporation is unprecedented and untested at the scale needed to meet plan requirements. All drainage management strategies that have been proposed
-
Geohydrologic reconnaissance of drainage wells in Florida
Kimrey, J.O.; Fayard, L.D.
1984-01-01
Drainage wells are used to inject surface waters directly into an aquifer, or shallow ground waters directly into a deeper aquifer, primarily by gravity. Such wells in Florida may be grouped into two broad types: (1) surface-water injection wells, and (2) interaquifer connector wells. Drainage wells of the first type are further categorized as either Floridan aquifer drainage wells or Biscayne aquifer drainage wells. Floridan aquifer drainage wells are commonly used to supplement drainage for urban areas in karst terranes of central and north Florida. Data are available for 25 wells in the Ocala, Live Oak, and Orlando areas that allow comparison of the quality of water samples from these Floridan aquifer drainage wells with allowable contaminant levels. Comparison indicates that maximum contaminant levels for turbidity, color, and iron, manganese, and lead concentrations are equaled or exceeded in some drainage-well samples, and relatively high counts for coliform bacteria are present in most wells. Biscayne aquifer drainage wells are used locally to dispose of stormwater runoff and other surplus water in southeast Florida, where large numbers of these wells have been permitted in Dade and Broward Counties. The majority of these wells are used to dispose of water from swimming pools or to dispose of heated water from air-conditioning units. The use of Biscayne aquifer drainage wells may have minimal effect on aquifer potability so long as injection of runoff and industrial wates is restricted to zones where chloride concentrations exceed 1,500 milligrams per liter. Interaquifer connector wells are used in the phosphate mining areas of Polk and Hillsborough Counties, to drain mines and recharge the Floridan aquifer. Water-quality data available from 13 connector wells indicate that samples from most of these wells exceed standards values for iron concentration and turbidity. One well yielded a highly mineralized water, and samples from 6 of the other 12 wells exceed
-
Advances in drainage: Selected works from the Tenth International Drainage Symposium
Strock, Jeffrey S.; Hay, Christopher; Helmers, Matthew; Nelson, Kelly A.; Sands, Gary R.; Skaggs, R. Wayne; Douglas-Mankin, Kyle R.
2018-01-01
This article introduces a special collection of fourteen articles accepted from among the 140 technical presentations, posters, and meeting papers presented at the 10th International ASABE Drainage Symposium. The symposium continued in the tradition of previous symposia that began in 1965 as a forum for presenting and assessing the progress of drainage research and implementation throughout the world. The articles in this collection address a wide range of topics grouped into five broad categories: (1) crop response, (2) design and management, (3) hydrology and scale, (4) modeling, and (5) water quality. The collection provides valuable information for scientists, engineers, planners, and others working on crop production, water quality, and water quantity issues affected by agricultural drainage. The collection also provides perspectives on the challenges of increasing agricultural production in a changing climate, with ever-greater attention to water quality and quantity concerns that will require integrated technical, economic, and social solutions.
-
Energy Technology Data Exchange (ETDEWEB)
Sutela, T.; Vuori, K.-M.; Louhi, P. [and others
2012-05-15
We have compiled in this review a comprehensive presentation of the impacts of acid sulphate soils (ASS) on water quality, biota, and fish kills in Finnish water bodies. This review is a result of extensive collaboration among research scientists in connection with the CATERMASS project co-ordinated by the Finnish Environment Institute (SYKE). Acid sulphate soils were formed in the eutrophic coastal waters of the Baltic Sea 4,000-8,000 years ago as microbes reduced the sulphate contained in saline seawater into sulphide. Sulphide clay soils emerging through land uplift have since been reclaimed and drained for cultivation use. Sulphur released in the resultant oxidation process reacted with soil water to form sulphuric acid, which draws toxic metals such as aluminium, cadmium, and copper from the soil. Heavy rains and the waters of springtime thawing transported acids and metals to the water bodies. In recent decades, the drainage depth of fields has increased because of the growing popularity of subterranean drainage methods, thus exacerbating the adverse ASS impacts on water bodies. Acidity and the attendant proliferation of toxic forms of metals induce changes in all organism groups of water biota, among them fish, macroinvertebrates, macrophytes, and bottom algae. On the specimen level, malformations have been discovered, such as structural pupae impairment in aquatic insects. The defence mechanism employed by fish against harmful substances in the surrounding water is to increase mucus exudation in the gills, which results in reduced respiration function. Exposure to acidity and metals harms the reproduction cycle of fish by delaying the development of follicles into mature eggs and by hindering eggs' fertilisation and embryo development. On the biota level, the manifestation of ASS impact is often the absence of the species or species groups most vulnerable to acidity. The species of river fish that are vulnerable to acidity include, for example
-
Vacuum horizontal drainage for depressurization of uranium tailings
International Nuclear Information System (INIS)
Pakalnis, R.; Chedsey, G.; Robertson, A.M.; Follin, S.
1985-01-01
A recent advance in tailings slope depressurization is the application of vacuum assist horizontal drainage. Horizontal drains have been used for several decades to reduce water pressures in slopes in order to improve stability. The benefit from vacuum assist arises from an increased hydraulic gradient caused by induced negative atmospheric pressures. The vacuum assist system has, since its inception in 1982, been successfully employed at two soil and four rock slope projects located in Western Canada. This paper describes the first application of this system in the United States. The technical feasibility of employing vacuum assisted horizontal drains to depressurize a uranium tailings dam near Riverton, Wyoming has been evaluated. Two horizontal drains (300 ft.) were installed and their effect monitored by nine piezometers. The study was conducted over a three-week internal with vacuum being applied for three and four day periods. The drawdowns achieved through vacuum drainage was found to be approximately double that obtained by gravity alone. The volume of water exhausted under vacuum during the seven day interval was approximately double that obtained by gravity alone
-
SWIM (Soil and Water Integrated Model)
Energy Technology Data Exchange (ETDEWEB)
Krysanova, V; Wechsung, F; Arnold, J; Srinivasan, R; Williams, J
2000-12-01
The model SWIM (Soil and Water Integrated Model) was developed in order to provide a comprehensive GIS-based tool for hydrological and water quality modelling in mesoscale and large river basins (from 100 to 10,000 km{sup 2}), which can be parameterised using regionally available information. The model was developed for the use mainly in Europe and temperate zone, though its application in other regions is possible as well. SWIM is based on two previously developed tools - SWAT and MATSALU (see more explanations in section 1.1). The model integrates hydrology, vegetation, erosion, and nutrient dynamics at the watershed scale. SWIM has a three-level disaggregation scheme 'basin - sub-basins - hydrotopes' and is coupled to the Geographic Information System GRASS (GRASS, 1993). A robust approach is suggested for the nitrogen and phosphorus modelling in mesoscale watersheds. SWIM runs under the UNIX environment. Model test and validation were performed sequentially for hydrology, crop growth, nitrogen and erosion in a number of mesoscale watersheds in the German part of the Elbe drainage basin. A comprehensive scheme of spatial disaggregation into sub-basins and hydrotopes combined with reasonable restriction on a sub-basin area allows performing the assessment of water resources and water quality with SWIM in mesoscale river basins. The modest data requirements represent an important advantage of the model. Direct connection to land use and climate data provides a possibility to use the model for analysis of climate change and land use change impacts on hydrology, agricultural production, and water quality. (orig.)
-
Development of subsurface drainage database system for use in environmental management issues
International Nuclear Information System (INIS)
Azhar, A.H.; Rafiq, M.; Alam, M.M.
2007-01-01
A simple user-friendly menue-driven system for database management pertinent to the Impact of Subsurface Drainage Systems on Land and Water Conditions (ISIAW) has been developed for use in environment-management issues of the drainage areas. This database has been developed by integrating four soft wares, viz; Microsoft Excel, MS Word Acrobat and MS Access. The information, in the form of tables and figures, with respect to various drainage projects has been presented in MS Word files. The major data-sets of various subsurface drainage projects included in the ISLaW database are: i) technical aspects, ii) groundwater and soil-salinity aspects, iii) socio-technical aspects, iv) agro-economic aspects, and v) operation and maintenance aspects. The various ISlAW file can be accessed just by clicking at the Menu buttons of the database system. This database not only gives feed back on the functioning of different subsurface drainage projects, with respect to the above-mentioned aspects, but also serves as a resource-document for these data for future studies on other drainage projects. The developed database-system is useful for planners, designers and Farmers Organisations for improved operation of existing drainage projects as well as development of future ones. (author)
-
International Nuclear Information System (INIS)
Aranda, Suzan; Borrok, David M.; Wanty, Richard B.; Balistrieri, Laurie S.
2012-01-01
The pollution of natural waters with metals derived from the oxidation of sulfide minerals like pyrite is a global environmental problem. However, the metal loading pathways and transport mechanisms associated with acid rock drainage reactions are often difficult to characterize using bulk chemical data alone. In this study, we evaluated the use of zinc (Zn) isotopes to complement traditional geochemical tools in the investigation of contaminated waters at the former Waldorf mining site in the Rocky Mountains, Colorado, U.S.A. Geochemical signatures and statistical analysis helped in identifying two primary metal loading pathways at the Waldorf site. The first was characterized by a circumneutral pH, high alkalinity, and high Zn/Cd ratios. The second was characterized by acidic pHs and low Zn/Cd ratios. Zinc isotope signatures in surface water samples collected across the site were remarkably similar (the δ 66 Zn, relative to JMC 3-0749-L, for most samples ranged from 0.20 to 0.30‰ ± 0.09‰ 2σ). This probably suggests that the ultimate source of Zn is consistent across the Waldorf site, regardless of the metal loading pathway. The δ 66 Zn of pore water samples collected within a nearby metal-impacted wetland area, however, were more variable, ranging from 0.20 to 0.80‰ ± 0.09‰ 2σ. Here the Zn isotopes seemed to reflect differences in groundwater flow pathways. However, a host of secondary processes might also have impacted Zn isotopes, including adsorption of Zn onto soil components, complexation of Zn with dissolved organic matter, uptake of Zn into plants, and the precipitation of Zn during the formation of reduced sulfur species. Zinc isotope analysis proved useful in this study; however, the utility of this isotopic tool would improve considerably with the addition of a comprehensive experimental foundation for interpreting the complex isotopic relationships found in soil pore waters. - Highlights: ► Zinc isotopes of water were measured in
-
Clark, Melanie L.; Mason, Jon P.
2007-01-01
Water-quality sampling was conducted regularly at stream sites within or near the Powder River structural basin in northeastern Wyoming and southeastern Montana during water years 2001-05 (October 1, 2000, to September 30, 2005) to characterize water quality in an area of coalbed natural gas development. The U.S. Geological Survey, in cooperation with the Wyoming Department of Environmental Quality, characterized the water quality at 22 sampling sites in the Tongue, Powder, Cheyenne, and Belle Fourche River drainage basins. Data for general hydrology, field measurements, major-ion chemistry, and selected trace elements were summarized, and specific conductance and sodium-adsorption ratios were evaluated for relations with streamflow and seasonal variability. Trend analysis for water years 1991-2005 was conducted for selected sites and constituents to assess change through time. Average annual runoff was highly variable among the stream sites. Generally, streams that have headwaters in the Bighorn Mountains had more runoff as a result of higher average annual precipitation than streams that have headwaters in the plains. The Powder River at Moorhead, Mont., had the largest average annual runoff (319,000 acre-feet) of all the sites; however, streams in the Tongue River drainage basin had the highest runoff per unit area of the four major drainage basins. Annual runoff in all major drainage basins was less than average during 2001-05 because of drought conditions. Consequently, water-quality samples collected during the study period may not represent long-term water-quality con-ditions for all sites. Water-quality characteristics were highly variable generally because of streamflow variability, geologic controls, and potential land-use effects. The range of median specific-conductance values among sites was smallest in the Tongue River drainage basin. Median values in that basin ranged from 643 microsiemens per centimeter at 25 degrees Celsius (?S/cm at 25?C) on the
-
Directory of Open Access Journals (Sweden)
W. A. Timms
2012-04-01
Full Text Available The magnitude and timing of deep drainage and salt leaching through clay soils is a critical issue for dryland agriculture in semi-arid regions (<500 mm yr−1 rainfall, potential evapotranspiration >2000 mm yr−1 such as parts of Australia's Murray-Darling Basin (MDB. In this rare study, hydrogeological measurements and estimations of the historic water balance of crops grown on overlying Grey Vertosols were combined to estimate the contribution of deep drainage below crop roots to recharge and salinization of shallow groundwater. Soil sampling at two sites on the alluvial flood plain of the Lower Namoi catchment revealed significant peaks in chloride concentrations at 0.8–1.2 m depth under perennial vegetation and at 2.0–2.5 m depth under continuous cropping indicating deep drainage and salt leaching since conversion to cropping. Total salt loads of 91–229 t ha−1 NaCl equivalent were measured for perennial vegetation and cropping, with salinity to ≥ 10 m depth that was not detected by shallow soil surveys. Groundwater salinity varied spatially from 910 to 2430 mS m−1 at 21 to 37 m depth (N = 5, whereas deeper groundwater was less saline (290 mS m−1 with use restricted to livestock and rural domestic supplies in this area. The Agricultural Production Systems Simulator (APSIM software package predicted deep drainage of 3.3–9.5 mm yr−1 (0.7–2.1% rainfall based on site records of grain yields, rainfall, salt leaching and soil properties. Predicted deep drainage was highly episodic, dependent on rainfall and antecedent soil water content, and over a 39 yr period was restricted mainly to the record wet winter of 1998. During the study period, groundwater levels were unresponsive to major rainfall events (70 and 190 mm total, and most piezometers at about 18 m depth remained dry. In this area, at this time, recharge appears to be negligible due to low
-
Time resolved analysis of water drainage in porous asphalt concrete using neutron radiography.
Poulikakos, L D; Sedighi Gilani, M; Derome, D; Jerjen, I; Vontobel, P
2013-07-01
Porous asphalt as a road surface layer controls aquaplaning as rain water can drain through its highly porous structure. The process of water drainage through this permeable layer is studied using neutron radiography. Time-resolved water configuration and distribution within the porous structure are reported. It is shown that radiography depicts the process of liquid water transport within the complex geometry of porous asphalt, capturing water films, filled dead end pores and water islands. Copyright © 2013 Elsevier Ltd. All rights reserved.
-
Metzen, D.; Sheridan, G. J.; Benyon, R. G.; Lane, P. N. J.
2015-12-01
In topographically complex terrain, the interaction of aspect-dependent solar exposure and drainage-position-dependent flow accumulation results in energy and water partitioning that is highly spatially variable. Catchment scale rainfall-runoff relationships are dependent on these smaller scale spatial patterns. However, there remains considerable uncertainty as to how to represent this smaller scale variability within lumped parameter, catchment scale rainfall-runoff models. In this study we aim to measure and represent the key interactions between aridity and drainage position in complex terrain to inform the development of simple catchment-scale hydrologic model parameters. Six measurement plots were setup on opposing slopes in an east-west facing eucalypt forest headwater catchment. The field sites are spanning three drainage positions with two contrasting aridity indices each, while minimizing variations in other factors, e.g. geology and weather patterns. Sapflow, soil water content (SWC) and throughfall were continuously monitored on two convergent hillslopes with similar size (1.3 and 1.6ha) but contrasting aspects (north and south). Soil depth varied from 0.6m at the topslope to >2m at the bottomslope positions. Maximum tree heights ranged from 16.2m to 36.9m on the equator-facing slope and from 30.1m to 45.5m on the pole-facing slope, with height decreasing upslope on both aspects. Two evapotranspiration (ET) patterns emerged in relation to aridity and drainage position. On the equator-facing slope (AI~ 2.1), seasonal understorey and overstorey ET patterns were in sync, whereas on the pole-facing slope (AI~1.5) understorey ET showed larger seasonal fluctuations than overstorey ET. Seasonal ET patterns and competition between soil evaporation and root water uptake lead to distinct differences in profile SWC across the sites, likely caused by depletion from different depths. Topsoil water content on equator-facing slopes was generally lower and responded
-
Voter, C. B.; Steven, L. I.
2015-12-01
The introduction impervious surfaces in urban areas is a key driver of hydrologic change. It is now well understood that the amount of "effective" impervious area directly connected to the storm sewer network is a better indicator of hydrologic behavior than the total amount of impervious area. Most studies in urban hydrology have focused on the relationship between impervious connectivity and stormwater runoff or other surface water flows, with the result that the effect on subsurface flow is not as well understood. In the field, we observe differences in soil moisture availability that are dependent on proximity to impervious features and significant from a root water uptake perspective, which indicates that parcel-scale subsurface and plant water fluxes may also be sensitive to fine-scaled heterogeneity in impervious surface arrangement and connectivity. We use ParFlow with CLM, a watershed model with fully integrated variably-saturated subsurface flow, overland flow, and land-surface processes, to explore the extent to which soil moisture, evapotranspiration, and deep drainage vary under various impervious surface arrangement and soil condition scenarios, as well as under a range of precipitation regimes. We investigate the effect of several impervious surface and soil characteristics, including general lot layout, downspout disconnect, and direction of driveway/sidewalk slope, and soil compaction. We show that that some impervious connectivity schemes transfer more water from impervious areas to pervious ones and promote localized recharge by developing well-defined, fast-moving wetting fronts that are able to penetrate the root zone. Enhanced infiltration is translated more directly to recharge in normal to wet years but partitioned more often to transpiration in dry years, leading to a nonlinear relationship among precipitation, runoff and recharge.
-
Measured and simulated soil water evaporation from four Great Plains soils
The amount of soil water lost during stage one and stage two soil water evaporation is of interest to crop water use modelers. The ratio of measured soil surface temperature (Ts) to air temperature (Ta) was tested as a signal for the transition in soil water evaporation from stage one to stage two d...
-
Directory of Open Access Journals (Sweden)
Carmo Horta
2012-06-01
input may exceed soil retention capacity for phosphate and could lead to loss/transfer of P from soil to drainage or runoff waters, contributing to non point source pollution of superficial waters. The main objective of this work was to evaluate the impact of outdoor pig production on soil P levels, its spatial and temporal distribution and also P loss from this area to drainage waters. Experimental outdoor pig production area has 2.8 ha, slope between 5 and 30%, with an animal charge of 9 adults/ha. An increase in soil P, evaluated by the Olsen procedure (P-Ol, and in P inorganic (Pi and organic (Po can be observed. In winter there are important P losses by rainfall but it was observed also a global increase in soil P levels with time. P lost in drainage waters is correlated with soil P-Olsen or Pi. Levels of soil P-Olsen above 20 mg kg-1 exceed soil P adsorbing capacity causing a significant increase in P transfer to drainage waters. Better management practices and a better choice of an area with less erosion risk are important, in order to prevent eutrophication of water bodies.
-
U.S. Geological Survey programs and investigations related to soil and water conservation
Osterkamp, W.R.; Gray, J.R.
2001-01-01
The U.S. Geological Survey has a rich tradition of collecting hydrologic data, especially for fluxes of water and suspended sediment, that provide a foundation for studies of soil and water conservation. Applied and basic research has included investigations of the effects of land use on rangelands, croplands, and forests; hazards mapping; derivation of flood and drought frequency, and other statistics related to streamflow and reservoir storage; development and application of models of rainfall-runoff relations, chemical quality, and sediment movement; and studies of the interactive processes of overland and channel flow with vegetation. Networks of streamgaging stations and (or) sampling sites within numerous drainage basins are yielding information that extends databases and enhances the ability to use those data for interpretive studies.
-
International Nuclear Information System (INIS)
1981-04-01
This Code of Practice covers all the drainage systems which may occur in the radioactive classified area of an establishment, namely surface water, foul, process and radioactive drainage. It also deals with final discharge lines. The Code of Practice concentrates on those aspects of drainage which require particular attention because the systems are in or from radioactive areas and typical illustrations are given in appendices. The Code makes references to sources of information on conventional aspects of drainage design. (author)
-
Paul, Angela P.; Thodal, Carl E.; Baker, Gretchen M.; Lico, Michael S.; Prudic, David E.
2014-01-01
Water in caves, discharging from springs, and flowing in streams in the upper Baker and Snake Creek drainages are important natural resources in Great Basin National Park, Nevada. Water and rock samples were collected from 15 sites during February 2009 as part of a series of investigations evaluating the potential for water resource depletion in the park resulting from the current and proposed groundwater withdrawals. This report summarizes general geochemical characteristics of water samples collected from the upper Baker and Snake Creek drainages for eventual use in evaluating possible hydrologic connections between the streams and selected caves and springs discharging in limestone terrain within each watershed.Generally, water discharging from selected springs in the upper Baker and Snake Creek watersheds is relatively young and, in some cases, has similar chemical characteristics to water collected from associated streams. In the upper Baker Creek drainage, geochemical data suggest possible hydrologic connections between Baker Creek and selected springs and caves along it. The analytical results for water samples collected from Wheelers Deep and Model Caves show characteristics similar to those from Baker Creek, suggesting a hydrologic connection between the creek and caves, a finding previously documented by other researchers. Generally, geochemical evidence does not support a connection between water flowing in Pole Canyon Creek to that in Model Cave, at least not to any appreciable extent. The water sample collected from Rosethorn Spring had relatively high concentrations of many of the constituents sampled as part of this study. This finding was expected as the water from the spring travelled through alluvium prior to being discharged at the surface and, as a result, was provided the opportunity to interact with soil minerals with which it came into contact. Isotopic evidence does not preclude a connection between Baker Creek and the water discharging from
-
International Nuclear Information System (INIS)
Matsuyama, Tsugufumi; Sakai, Yasuhiro; Izumoto, Yukie; Imaseki, Hitoshi; Hamano, Tsuyoshi; Yoshii, Hiroshi
2017-01-01
Uranium concentrations in drainage water are typically determined by α-spectrometry. However, due to the low specific radioactivity of uranium, the evaporation of large volumes of drainage water, followed by several hours of measurements, is required. Thus, the development of a rapid and simple detection method for uranium in drainage water would enhance the operation efficiency of radiation control workers. We herein propose a novel methodology based on total reflection X-ray fluorescence (TXRF) for the measurement of uranium in contaminated water. TXRF is a particularly desirable method for the rapid and simple evaluation of uranium in contaminated water, as chemical pretreatment of the sample solution is not necessary, measurement times are typically several seconds, and the required sample volume is low. We herein employed sample solutions containing several different concentrations of uranyl acetate with yttrium as an internal standard. The solutions were placed onto sample holders, and were dried prior to TXRF measurements. The relative intensity, otherwise defined as the net intensity ratio of the Lα peak of uranium to the Kα peak of yttrium, was directly proportional to the uranium concentration. Using this method, a TXRF detection limit for uranium in contaminated water of 0.30 μg/g was achieved. (author)
-
Measuring Soil Water Potential for Water Management in Agriculture: A Review
Directory of Open Access Journals (Sweden)
Marco Bittelli
2010-05-01
Full Text Available Soil water potential is a soil property affecting a large variety of bio-physical processes, such as seed germination, plant growth and plant nutrition. Gradients in soil water potential are the driving forces of water movement, affecting water infiltration, redistribution, percolation, evaporation and plants’ transpiration. The total soil water potential is given by the sum of gravity, matric, osmotic and hydrostatic potential. The quantification of the soil water potential is necessary for a variety of applications both in agricultural and horticultural systems such as optimization of irrigation volumes and fertilization. In recent decades, a large number of experimental methods have been developed to measure the soil water potential, and a large body of knowledge is now available on theory and applications. In this review, the main techniques used to measure the soil water potential are discussed. Subsequently, some examples are provided where the measurement of soil water potential is utilized for a sustainable use of water resources in agriculture.
-
Directory of Open Access Journals (Sweden)
VERIDIANA P. CAMPANER
2014-06-01
Full Text Available Acid drainage influence on the water and sediment quality was investigated in a coal mining area (southern Brazil. Mine drainage showed pH between 3.2 and 4.6 and elevated concentrations of sulfate, As and metals, of which, Fe, Mn and Zn exceeded the limits for the emission of effluents stated in the Brazilian legislation. Arsenic also exceeded the limit, but only slightly. Groundwater monitoring wells from active mines and tailings piles showed pH interval and chemical concentrations similar to those of mine drainage. However, the river and ground water samples of municipal public water supplies revealed a pH range from 7.2 to 7.5 and low chemical concentrations, although Cd concentration slightly exceeded the limit adopted by Brazilian legislation for groundwater. In general, surface waters showed large pH range (6 to 10.8, and changes caused by acid drainage in the chemical composition of these waters were not very significant. Locally, acid drainage seemed to have dissolved carbonate rocks present in the local stratigraphic sequence, attenuating the dispersion of metals and As. Stream sediments presented anomalies of these elements, which were strongly dependent on the proximity of tailings piles and abandoned mines. We found that precipitation processes in sediments and the dilution of dissolved phases were responsible for the attenuation of the concentrations of the metals and As in the acid drainage and river water mixing zone. In general, a larger influence of mining activities on the chemical composition of the surface waters and sediments was observed when enrichment factors in relation to regional background levels were used.
-
Campaner, Veridiana P; Luiz-Silva, Wanilson; Machado, Wilson
2014-05-14
Acid drainage influence on the water and sediment quality was investigated in a coal mining area (southern Brazil). Mine drainage showed pH between 3.2 and 4.6 and elevated concentrations of sulfate, As and metals, of which, Fe, Mn and Zn exceeded the limits for the emission of effluents stated in the Brazilian legislation. Arsenic also exceeded the limit, but only slightly. Groundwater monitoring wells from active mines and tailings piles showed pH interval and chemical concentrations similar to those of mine drainage. However, the river and ground water samples of municipal public water supplies revealed a pH range from 7.2 to 7.5 and low chemical concentrations, although Cd concentration slightly exceeded the limit adopted by Brazilian legislation for groundwater. In general, surface waters showed large pH range (6 to 10.8), and changes caused by acid drainage in the chemical composition of these waters were not very significant. Locally, acid drainage seemed to have dissolved carbonate rocks present in the local stratigraphic sequence, attenuating the dispersion of metals and As. Stream sediments presented anomalies of these elements, which were strongly dependent on the proximity of tailings piles and abandoned mines. We found that precipitation processes in sediments and the dilution of dissolved phases were responsible for the attenuation of the concentrations of the metals and As in the acid drainage and river water mixing zone. In general, a larger influence of mining activities on the chemical composition of the surface waters and sediments was observed when enrichment factors in relation to regional background levels were used.
-
A Comparison of Soil-Water Sampling Techniques
Tindall, J. A.; Figueroa-Johnson, M.; Friedel, M. J.
2007-12-01
The representativeness of soil pore water extracted by suction lysimeters in ground-water monitoring studies is a problem that often confounds interpretation of measured data. Current soil water sampling techniques cannot identify the soil volume from which a pore water sample is extracted, neither macroscopic, microscopic, or preferential flowpath. This research was undertaken to compare values of extracted suction lysimeters samples from intact soil cores with samples obtained by the direct extraction methods to determine what portion of soil pore water is sampled by each method. Intact soil cores (30 centimeter (cm) diameter by 40 cm height) were extracted from two different sites - a sandy soil near Altamonte Springs, Florida and a clayey soil near Centralia in Boone County, Missouri. Isotopically labeled water (O18? - analyzed by mass spectrometry) and bromide concentrations (KBr- - measured using ion chromatography) from water samples taken by suction lysimeters was compared with samples obtained by direct extraction methods of centrifugation and azeotropic distillation. Water samples collected by direct extraction were about 0.25 ? more negative (depleted) than that collected by suction lysimeter values from a sandy soil and about 2-7 ? more negative from a well structured clayey soil. Results indicate that the majority of soil water in well-structured soil is strongly bound to soil grain surfaces and is not easily sampled by suction lysimeters. In cases where a sufficient volume of water has passed through the soil profile and displaced previous pore water, suction lysimeters will collect a representative sample of soil pore water from the sampled depth interval. It is suggested that for stable isotope studies monitoring precipitation and soil water, suction lysimeter should be installed at shallow depths (10 cm). Samples should also be coordinated with precipitation events. The data also indicate that each extraction method be use to sample a different
-
Liu, Xiaonan; Wu, Zhifeng; Cheng, Jiong; Liu, Ping
2008-10-01
The output of nitrogen and phosphorus from agricultural activities is the main source for water eutrophication. The fully developed agriculture in vegetables, fruits and flowers in Pearl River Delta gives rise to excessive use of chemical matter such as fertilizer and pesticide and thus bring about the serious water pollution because of the loss of nitrogen (N) and phosphorus (P) from the farmland in the region. Based on Geographic Information System (GIS) and soil pollution data, Universal Soil Loss Equation (USLE) and source type method are used to estimate the loads of particulate N and P from the soil of different land use types in the drainage area of Liuxi River in Guangzhou, China. So the key regions those the NPS pollution occurred can be confirmed and the technical support for the pollution control target and the capital flow concentration can be provided by the results. The study shows that, (1) The total loss of particulate N and P in the drainage area is 582.49 t/a and 424.74 t/a respectively. Among them the loss of particulate N from paddy soil occupies 40.02% and that of forest 6.31%, while the loss of particulate P from the soil of dry-land accounts for 28.75% and that of paddy soil 26.31%. (2) There are significantly different losses of particulate N and P per unit area from the soils of different source land use types in the drainage area. The losses of particulate N and P per unit area are both the highest from the soil of dry-land, which is 7.72 kg/hm2 and 9.50 kg/hm2 respectively, followed by those of orchard, which is 7.20 kg/hm2 and 6.56 kg/hm2 respectively. The causes are excessive use of chemical matter, unreasonable cultivation pattern, and the soil erosion of different land use. (3) The excessive N and P come from the loss of particulate N and P from the fertilization in agricultural production, and they are the main source of the pollutants in Liuxi River water.
-
Soil salinization processes in rice irrigation schemes in the Senegal River Delta
International Nuclear Information System (INIS)
Ceuppens, J.; Wopereis, M.C.S.; Miezan, K.M.
1997-01-01
Soil salinization constitutes a major threat to irrigated agriculture (mainly rice, Oryza sativa L.) in the Senegal River Delta. It is generally hypothesized that salinization is caused by (i) capillary rise from a saline water table and (ii) concentration of salts in the field due to lack of adequate drainage facilities. The impact of field water management and rice cropping intensity on salinization in the Delta was determined using an electromagnetic conductivity meter (Geonics EM38). More than 4000 measurements were made in 40 rice fields on a typical heavy clay soil (Vertic Xerofluvent). Thirty EM38 measurements per field (0.25 ha) estimated average field soil salinity with a relative error of 20%. A multiple linear regression model based on EM38 readings explained 60 to 75% of the variability in conductivity of 1:5 saturation extracts at 0- to 5-, 10- to 15-, and 30- to 35-cm depths. Higher cropping intensity limited upward salt transport from the water table. Average horizontal and vertical EM38 measurements increased in the following order two rice crops per year with drainage: 0.73 and 0.98 dS m -1 ; one rice crop per year with drainage: 1.26 and 1.76 dS m -1 ; one rice crop per year without drainage: 2.23 and 2.98 dS m -1 ; and abandoned fields: 4.77 and 4.29 dS m -1 . Results indicate a beneficial effect of flooded rice on salinity for this type of heavy clay soil. Irrigation development in the area needs to be accompanied by monitoring of water table depth. (author)
-
Moriasi, Daniel N; Gowda, Prasanna H; Arnold, Jeffrey G; Mulla, David J; Ale, Srinivasulu; Steiner, Jean L; Tomer, Mark D
2013-11-01
Subsurface tile drains in agricultural systems of the midwestern United States are a major contributor of nitrate-N (NO-N) loadings to hypoxic conditions in the Gulf of Mexico. Hydrologic and water quality models, such as the Soil and Water Assessment Tool, are widely used to simulate tile drainage systems. The Hooghoudt and Kirkham tile drain equations in the Soil and Water Assessment Tool have not been rigorously tested for predicting tile flow and the corresponding NO-N losses. In this study, long-term (1983-1996) monitoring plot data from southern Minnesota were used to evaluate the SWAT version 2009 revision 531 (hereafter referred to as SWAT) model for accurately estimating subsurface tile drain flows and associated NO-N losses. A retention parameter adjustment factor was incorporated to account for the effects of tile drainage and slope changes on the computation of surface runoff using the curve number method (hereafter referred to as Revised SWAT). The SWAT and Revised SWAT models were calibrated and validated for tile flow and associated NO-N losses. Results indicated that, on average, Revised SWAT predicted monthly tile flow and associated NO-N losses better than SWAT by 48 and 28%, respectively. For the calibration period, the Revised SWAT model simulated tile flow and NO-N losses within 4 and 1% of the observed data, respectively. For the validation period, it simulated tile flow and NO-N losses within 8 and 2%, respectively, of the observed values. Therefore, the Revised SWAT model is expected to provide more accurate simulation of the effectiveness of tile drainage and NO-N management practices. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.
-
Liu, W.; Youssef, M.; Birgand, F.; Chescheir, G. M.; Maxwell, B.; Tian, S.
2017-12-01
Agricultural drainage is a practice used to artificially enhance drainage characteristics of naturally poorly drained soils via subsurface drain tubing or open-ditch systems. Approximately 25% of the U.S. agricultural land requires improved drainage for economic crop production. However, drainage increases the transport of dissolved agricultural chemicals, particularly nitrates to downstream surface waters. Nutrient export from artificially drained agricultural landscapes has been identified as the leading source of elevated nutrient levels in major surface water bodies in the U.S. Controlled drainage has long been practiced to reduce nitrogen export from agricultural fields to downstream receiving waters. It has been hypothesized that controlled drainage reduces nitrogen losses by promoting denitrification, reducing drainage outflow from the field, and increasing plant uptake. The documented performance of the practice was widely variable as it depends on several site-specific factors. The goal of this research was to utilize high frequency measurements to investigate the effect of agricultural drainage and related management practices on nitrate fate and transport for an artificially drained agricultural field in eastern North Carolina. We deployed a field spectrophotometer to measure nitrate concentration every 45 minutes and measured drainage flow rate using a V-notch weir every 15 minutes. Furthermore, we measured groundwater level, precipitation, irrigation amount, temperature to characterize antecedent conditions for each event. Nitrate concentration-drainage flow (C-Q) relationships generated from the high frequency measurements illustrated anti-clockwise hysteresis loops and nitrate flushing mechanism in response to most precipitation and irrigation events. Statistical evaluation will be carried out for the C-Q relationships. The results of our analysis, combined with numerical modeling, will provide a better understanding of hydrological and
-
Water and solute balances as a basis for sustainable irrigation agriculture
Pla-Sentís, Ildefonso
2015-04-01
The growing development of irrigated agriculture is necessary for the sustainable production of the food required by the increasing World's population. Such development is limited by the increasing scarcity and low quality of the available water resources and by the competitive use of the water for other purposes. There are also increasing problems of contamination of surface and ground waters to be used for other purposes by the drainage effluents of irrigated lands. Irrigation and drainage may cause drastic changes in the regime and balance of water and solutes (salts, sodium, contaminants) in the soil profile, resulting in problems of water supply to crops and problems of salinization, sodification and contamination of soils and ground waters. This is affected by climate, crops, soils, ground water depth, irrigation and groundwater composition, and by irrigation and drainage management. In order to predict and prevent such problems for a sustainable irrigated agriculture and increased efficiency in water use, under each particular set of conditions, there have to be considered both the hydrological, physical and chemical processes determining such water and solute balances in the soil profile. In this contribution there are proposed the new versions of two modeling approaches (SOMORE and SALSODIMAR) to predict those balances and to guide irrigation water use and management, integrating the different factors involved in such processes. Examples of their application under Mediterranean and tropical climate conditions are also presented.
-
International Nuclear Information System (INIS)
Anon.
1994-01-01
Volume 1 of these proceedings is divided into the following sections: Modeling mine water quality; Water treatment with wetlands; Predicting mine water quality; Water treatment--Chemical; Control of acid mine drainage--Wet covers; Site characterization monitoring; Control of acid mine drainage--Alkaline addition; and Mine water geochemistry. Papers dealing with or applicable to coal or uranium mining have been processed separately for inclusion on the data base
-
Knight, John; Raats, Peter
2016-04-01
The EGU Division on Nonlinear Processes in Geophysics awards the Lewis Fry Richardson Medal. Richardson's significance is highlighted in http://www.egu.eu/awards-medals/portrait-lewis-fry-richardson/, but his contributions to soil physics and to numerical solutions of heat and diffusion equations are not mentioned. We would like to draw attention to those little known contributions. Lewis Fry Richardson (1881-1953) made important contributions to many fields including numerical weather prediction, finite difference solutions of partial differential equations, turbulent flow and diffusion, fractals, quantitative psychology and studies of conflict. He invented numerical weather prediction during World War I, although his methods were not successfully applied until 1950, after the invention of fast digital computers. In 1922 he published the book `Numerical weather prediction', of which few copies were sold and even fewer were read until the 1950s. To model heat and mass transfer in the atmosphere, he did much original work on turbulent flow and defined what is now known as the Richardson number. His technique for improving the convergence of a finite difference calculation is known as Richardson extrapolation, and was used by John Philip in his 1957 semi-analytical solution of the Richards equation for water movement in unsaturated soil. Richardson's first papers in 1908 concerned the numerical solution of the free surface problem of unconfined flow of water in saturated soil, arising in the design of drain spacing in peat. Later, for the lower boundary of his atmospheric model he needed to understand the movement of heat, liquid water and water vapor in what is now called the vadose zone and the soil plant atmosphere system, and to model coupled transfer of heat and flow of water in unsaturated soil. Finding little previous work, he formulated partial differential equations for transient, vertical flow of liquid water and for transfer of heat and water vapor. He
-
Thodal, Carl E.; Tuttle, Peter L.
1996-01-01
in several biological samples collected throughout the Basin, although concentrations in water and bottom sediment were below analytical reporting limits. Sources of arsenic, boron, and mercury in the Basin are uncertain, but ambient levels reported for a variety of sample matrices collected from western Nevada generally exceed ranges cited as natural background levels. Because these potentially toxic constituents exceeded concern levels in areas that do not directly receive irrigation drainage, concentrations measured in samples collected for this study may not necessarily be attributable to agricultural activities. Diversion of river water for irrigation may have greater effects on beneficial uses of water and on fish and wildlife than does drainage from agricultural areas on the Reservation. In 1994, agricultural water consumption precluded dilution of ground-water seepage to the river channel. This resulted in concentrations of potentially toxic solutes that exceeded levels of concern. Diversion of irrigation water also may have facilitated leaching of potentially toxic solutes from irrigated soil on the Reservation, but during this study all water applied for irrigation on the Reservation was either consumed by evapotranspiration or infiltrated to recharge shallow ground water. No irrigation drainage was found on the Reservation during this study. However, because 1994 samples of ground-water seepage to the Walker River channel exceeded at least six Nevada waterquality standards, water-quality problems may result should ground-water levels rise enough to cause ground-water discharge to the agricultural drain on the Reservation. Nevertheless, the potential for adverse effects from irrigation drainage on the Reservation is believed to be small because surface-water rights for the Walker River Indian Reservation amount to only 2 percent of total surface- water rights in the entire Walker River Basin.
-
Reconnecting tile drainage to riparian buffer hydrology for enhanced nitrate removal.
Jaynes, D B; Isenhart, T M
2014-03-01
Riparian buffers are a proven practice for removing NO from overland flow and shallow groundwater. However, in landscapes with artificial subsurface (tile) drainage, most of the subsurface flow leaving fields is passed through the buffers in drainage pipes, leaving little opportunity for NO removal. We investigated the feasibility of re-routing a fraction of field tile drainage as subsurface flow through a riparian buffer for increasing NO removal. We intercepted an existing field tile outlet draining a 10.1-ha area of a row-cropped field in central Iowa and re-routed a fraction of the discharge as subsurface flow along 335 m of an existing riparian buffer. Tile drainage from the field was infiltrated through a perforated pipe installed 75 cm below the surface by maintaining a constant head in the pipe at a control box installed in-line with the existing field outlet. During 2 yr, >18,000 m (55%) of the total flow from the tile outlet was redirected as infiltration within the riparian buffer. The redirected water seeped through the 60-m-wide buffer, raising the water table approximately 35 cm. The redirected tile flow contained 228 kg of NO. On the basis of the strong decrease in NO concentrations within the shallow groundwater across the buffer, we hypothesize that the NO did not enter the stream but was removed within the buffer by plant uptake, microbial immobilization, or denitrification. Redirecting tile drainage as subsurface flow through a riparian buffer increased its NO removal benefit and is a promising management practice to improve surface water quality within tile-drained landscapes. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.
-
Characterization of soil water content variability and soil texture using GPR groundwave techniques
Energy Technology Data Exchange (ETDEWEB)
Grote, K.; Anger, C.; Kelly, B.; Hubbard, S.; Rubin, Y.
2010-08-15
Accurate characterization of near-surface soil water content is vital for guiding agricultural management decisions and for reducing the potential negative environmental impacts of agriculture. Characterizing the near-surface soil water content can be difficult, as this parameter is often both spatially and temporally variable, and obtaining sufficient measurements to describe the heterogeneity can be prohibitively expensive. Understanding the spatial correlation of near-surface soil water content can help optimize data acquisition and improve understanding of the processes controlling soil water content at the field scale. In this study, ground penetrating radar (GPR) methods were used to characterize the spatial correlation of water content in a three acre field as a function of sampling depth, season, vegetation, and soil texture. GPR data were acquired with 450 MHz and 900 MHz antennas, and measurements of the GPR groundwave were used to estimate soil water content at four different times. Additional water content estimates were obtained using time domain reflectometry measurements, and soil texture measurements were also acquired. Variograms were calculated for each set of measurements, and comparison of these variograms showed that the horizontal spatial correlation was greater for deeper water content measurements than for shallower measurements. Precipitation and irrigation were both shown to increase the spatial variability of water content, while shallowly-rooted vegetation decreased the variability. Comparison of the variograms of water content and soil texture showed that soil texture generally had greater small-scale spatial correlation than water content, and that the variability of water content in deeper soil layers was more closely correlated to soil texture than were shallower water content measurements. Lastly, cross-variograms of soil texture and water content were calculated, and co-kriging of water content estimates and soil texture
-
Energy Technology Data Exchange (ETDEWEB)
Gunn, J.M.; Sein, R.; Keller, B. [Laurentian Univ., Sudbury, ON (Canada) Dept. of Biology
1999-07-01
A study was carried out to test whether INCO Ltd.'s aerial land liming program, designed solely for revegetation purposes, was improving water quality from the treated sites in an area affected by air pollution from acidic nickel and copper smelters. A wetland application mehod was tested as a potentially improved technique of drainage water treatment. A summary is included of the results of water quality assessment and bioassay toxicity testing for the experimental catchments during the study period 1991-1997. There were immediate spin-off benefits from the stream monitoring study that were rapidly applied to the larger land reclamation effort. The identified effectivess of the coarse limestone led to testing and adoption of new methods of aerial liming in which finer pelletized materials were used both reducing the application rate and the associated costs. The decline in Cu and Ni during 1991-1994 indicated that the metal contamination of the site was declining even before the first limestone treatment. The occurrence of a brief pulse in metal concentrations immediately after the wetland liming treatments is consistent with an earlier occurrence and supports the hypothesis that liming may temporarily increase metal concentrations in stream water through displacement of metal cations at the soil exchange sites by the added Ca. The presence of acidic groundwater proved to be a confounding factor that reduced the effectiveness of soil and wetland treatments at the site. In spite of surprises, the catchment treatments, particularly the wetland applications, proved to be very effective at improving water quality in much of the catchment stream. 14 refs., 2 figs., 1 tab.
-
Serrano-Coronel, Genaro; Chipana-Rivera, René; Fátima Moreno-Pérez, María; Roldán-Cañas, José
2016-04-01
Among the most important hydraulic structures of pre-Hispanic ancestral technology developed in the Andean region, we find the suka kollus, aymara word, called also waru waru, en quechua or raised fields, in English. They are raised platforms surrounded by water canals that irrigate subsurface, but also have the function of draining, to deal with floods because they are surrounding Lake Titicaca. They also have the property of generating a thermoregulatory effect to crops, depending on the configuration of the channels and platforms. Such agro-ecosystems are being abandoned, however, if properly addressed crop management and some drainage canals are replaced by underground drains for increased crop area could be very useful in enabling marginal soils affected by salts and / or excess water. For these reasons, the objective of this study was to evaluate the subsurface irrigation in the potato crop in suka kollus under a system of surface drainage, and mixed drainage (surface and subsurface). The study was conducted in marginal soils of Kallutaca area, located 30 km from the city of La Paz, Bolivia, at a height of 3892 m.a.s.l. The cultivation of the potato (Solanum tuberosum ssp. Andigena) was used. Four treatments were tested with different widths of the platforms: T1 (Control) with drainage through channels; T2 (replacing a channel by a drain); T3 (replacing two channels by two drains); T4 (replacing three channels by three drains). The flow of water into the soil from the water table was predominantly upward, except during periods of high rainfall. In terms of treatments, the flow in T1 was higher, mainly at weeks 8 to 11 after seedling emergence, coinciding with the phenological phases of flowering and at the beginning of the tuber ripening. It was followed by T3, T2 and T4 treatments, respectively. Tuber yield, if one considers that the channels detract arable land, was higher in the T3 treatment,16.4 Mg / ha, followed by T2 treatment, 15.2 Mg / ha, T1
-
Groh, Tyler A; Gentry, Lowell E; David, Mark B
2015-05-01
Loss of nitrate from agricultural lands to surface waters is an important issue, especially in areas that are extensively tile drained. To reduce these losses, a wide range of in-field and edge-of-field practices have been proposed, including constructed wetlands. We re-evaluated constructed wetlands established in 1994 that were previously studied for their effectiveness in removing nitrate from tile drainage water. Along with this re-evaluation, we measured the production and flux of greenhouse gases (GHGs) (CO, NO, and CH). The tile inlets and outlets of two wetlands were monitored for flow and N during the 2012 and 2013 water years. In addition, seepage rates of water and nitrate under the berm and through the riparian buffer strip were measured. Greenhouse gas emissions from the wetlands were measured using floating chambers (inundated fluxes) or static chambers (terrestrial fluxes). During this 2-yr study, the wetlands removed 56% of the total inlet nitrate load, likely through denitrification in the wetland. Some additional removal of nitrate occurred in seepage water by the riparian buffer strip along each berm (6.1% of the total inlet load, for a total nitrate removal of 62%). The dominant GHG emitted from the wetlands was CO, which represented 75 and 96% of the total GHG emissions during the two water years. The flux of NO contributed between 3.7 and 13% of the total cumulative GHG flux. Emissions of NO were 3.2 and 1.3% of the total nitrate removed from wetlands A and B, respectively. These wetlands continue to remove nitrate at rates similar to those measured after construction, with relatively little GHG gas loss. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.
-
Simulation-based optimization framework for reuse of agricultural drainage water in irrigation.
Allam, A; Tawfik, A; Yoshimura, C; Fleifle, A
2016-05-01
A simulation-based optimization framework for agricultural drainage water (ADW) reuse has been developed through the integration of a water quality model (QUAL2Kw) and a genetic algorithm. This framework was applied to the Gharbia drain in the Nile Delta, Egypt, in summer and winter 2012. First, the water quantity and quality of the drain was simulated using the QUAL2Kw model. Second, uncertainty analysis and sensitivity analysis based on Monte Carlo simulation were performed to assess QUAL2Kw's performance and to identify the most critical variables for determination of water quality, respectively. Finally, a genetic algorithm was applied to maximize the total reuse quantity from seven reuse locations with the condition not to violate the standards for using mixed water in irrigation. The water quality simulations showed that organic matter concentrations are critical management variables in the Gharbia drain. The uncertainty analysis showed the reliability of QUAL2Kw to simulate water quality and quantity along the drain. Furthermore, the sensitivity analysis showed that the 5-day biochemical oxygen demand, chemical oxygen demand, total dissolved solids, total nitrogen and total phosphorous are highly sensitive to point source flow and quality. Additionally, the optimization results revealed that the reuse quantities of ADW can reach 36.3% and 40.4% of the available ADW in the drain during summer and winter, respectively. These quantities meet 30.8% and 29.1% of the drainage basin requirements for fresh irrigation water in the respective seasons. Copyright © 2016 Elsevier Ltd. All rights reserved.
-
Directory of Open Access Journals (Sweden)
A. Comegna
2010-12-01
Full Text Available Unsaturated hydraulic properties and their spatial variability today are analyzed in order to use properly mathematical models developed to simulate flow of the water and solute movement at the field-scale soils. Many studies have shown that observations of soil hydraulic properties should not be considered purely random, given that they possess a structure which may be described by means of stochastic processes. The techniques used for analyzing such a structure have essentially been based either on the theory of regionalized variables or to a lesser extent, on the analysis of time series. This work attempts to use the time-series approach mentioned above by means of a study of pressure head h and water content θ which characterize soil water status, in the space-time domain. The data of the analyses were recorded in the open field during a controlled drainage process, evaporation being prevented, along a 50 m transect in a volcanic Vesuvian soil. The isotropic hypothesis is empirical proved and then the autocorrelation ACF and the partial autocorrelation functions PACF were used to identify and estimate the ARMA(1,1 statistical model for the analyzed series and the AR(1 for the extracted signal. Relations with a state-space model are investigated, and a bivariate AR(1 model fitted. The simultaneous relations between θ and h are considered and estimated. The results are of value for sampling strategies and they should incite to a larger use of time and space series analysis.
-
DEFF Research Database (Denmark)
Muff, Jens; Erichsen, Rasmus; Damgaard, Christian
2008-01-01
Drainage water from a depot of chemical waste, polluted with a mixture of organophosphates and degradation products was treated by a direct as well as an indirect electrochemical method using a Ti/Pt-Ir anode and Stainless Steel 304 cathode. With a concentration of 0.7%, sodium chloride...... the treatment. Indirect electrochemical treatment, where a highly oxidized brine solution was added to the drainage water, revealed immediately reduction in COD, and similar to the direct treatment, degradation of all of the pesticide pollutants was obtained except for the O,O,O-triethyl-phosphoric acid...... concentrations. Analyses of the actual pollutants, Me-Parathion, parathion, malathion and degradation products, confirmed that the concentrations of all initial pollutants were eliminated during the treatment. The only exception was O,O,O-triethyl-phosphoric acid, a degradation product which was formed during...
-
DEFF Research Database (Denmark)
Muff, Jens; Erichsen, Rasmus; Damgaard, Christian
2008-01-01
the treatment. Indirect electrochemical treatment, where a highly oxidized brine solution was added to the drainage water, revealed immediately reduction in COD, and similar to the direct treatment, degradation of all of the pesticide pollutants was obtained except for the O,O,O-triethyl-phosphoric acid......Drainage water from a depot of chemical waste, polluted with a mixture of organophosphates and degradation products was treated by a direct as well as an indirect electrochemical method using a Ti/Pt-Ir anode and Stainless Steel 304 cathode. With a concentration of 0.7%, sodium chloride...... concentrations. Analyses of the actual pollutants, Me-Parathion, parathion, malathion and degradation products, confirmed that the concentrations of all initial pollutants were eliminated during the treatment. The only exception was O,O,O-triethyl-phosphoric acid, a degradation product which was formed during...
-
Soil Water: Advanced Crop and Soil Science. A Course of Study.
Miller, Larry E.
The course of study represents the fourth of six modules in advanced crop and soil science and introduces the agriculture student to the topic of soil water. Upon completing the three day module, the student will be able to classify water as to its presence in the soil, outline the hydrological cycle, list the ways water is lost from the soil,…
-
Linking soil type and rainfall characteristics towards estimation of surface evaporative capacitance
Or, D.; Bickel, S.; Lehmann, P.
2017-12-01
Separation of evapotranspiration (ET) to evaporation (E) and transpiration (T) components for attribution of surface fluxes or for assessment of isotope fractionation in groundwater remains a challenge. Regional estimates of soil evaporation often rely on plant-based (Penman-Monteith) ET estimates where is E is obtained as a residual or a fraction of potential evaporation. We propose a novel method for estimating E from soil-specific properties, regional rainfall characteristics and considering concurrent internal drainage that shelters soil water from evaporation. A soil-dependent evaporative characteristic length defines a depth below which soil water cannot be pulled to the surface by capillarity; this depth determines the maximal soil evaporative capacitance (SEC). The SEC is recharged by rainfall and subsequently emptied by competition between drainage and surface evaporation (considering canopy interception evaporation). We show that E is strongly dependent on rainfall characteristics (mean annual, number of storms) and soil textural type, with up to 50% of rainfall lost to evaporation in loamy soil. The SEC concept applied to different soil types and climatic regions offers direct bounds on regional surface evaporation independent of plant-based parameterization or energy balance calculations.
-
Use of biochar amendments for removing bacteria from simulated tile-drainage waters
The addition of biochar has been shown to increase bacterial removal rates by several orders of magnitude in sand-packed columns, suggesting that biochar may be a suitable amendment for use in end-of-tile filter systems to remove indicator and pathogenic microorganisms in tile-drainage waters. Addit...
-
International Nuclear Information System (INIS)
Di Lella, Luigi Antonello; Protano, Giuseppe; Riccobono, Francesco
2005-01-01
Acid drainage (AD) is a natural process occurring locally at the Earth's surface. It consists in a substantial increase of acidity of surface waters as a result of chemical reactions occurring in the atmosphere (i.e. acid rain) or involving reactive phases (i.e. pyrite) present in the percolated medium. Acidic surface waters (usually pH < 4) can be produced by oxidation of sulphides (mainly pyrite and other iron sulphides) exposed to atmospheric oxygen, while human activities, such as mining, can greatly enhance this process. Acid drainage promoted by mining activities is called acid mine drainage (AMD) and is a primary source of environmental pollution and a world-wide problem in both active and abandoned mining areas. In fact, exposure of iron sulphides to oxidising conditions produces strongly acidic drainage waters rich in sulphate and a variety of heavy elements (i.e. As, Cd, Pb, Sb). Several occurrences of active acid mine drainage have been found in the Metalliferous Hills (southern Tuscany). The most important AMD phenomena were observed in the Fenice Capanne and Niccioleta mining areas
-
Water-quality trends in the Scituate reservoir drainage area, Rhode Island, 1983-2012
Smith, Kirk P.
2015-01-01
The Scituate Reservoir is the primary source of drinking water for more than 60 percent of the population of Rhode Island. Water-quality and streamflow data collected at 37 surface-water monitoring stations in the Scituate Reservoir drainage area, Rhode Island, from October 2001 through September 2012, water years (WYs) 2002-12, were analyzed to determine water-quality conditions and constituent loads in the drainage area. Trends in water quality, including physical properties and concentrations of constituents, were investigated for the same period and for a longer period from October 1982 through September 2012 (WYs 1983-2012). Water samples were collected and analyzed by the Providence Water Supply Board, the agency that manages the Scituate Reservoir. Streamflow data were collected by the U.S. Geological Survey. Median values and other summary statistics for pH, color, turbidity, alkalinity, chloride, nitrite, nitrate, total coliform bacteria, Escherichia coli (E. coli), and orthophosphate were calculated for WYs 2003-12 for all 37 monitoring stations. Instantaneous loads and yields (loads per unit area) of total coliform bacteria and E. coli, chloride, nitrite, nitrate, and orthophosphate were calculated for all sampling dates during WYs 2003-12 for 23 monitoring stations with streamflow data. Values of physical properties and concentrations of constituents were compared with State and Federal water-quality standards and guidelines and were related to streamflow, land-use characteristics, varying classes of timber operations, and impervious surface areas.
-
Soil-Water Repellency Characteristic Curves for Soil Profiles with Organic Carbon Gradients
DEFF Research Database (Denmark)
Wijewardana, Nadeeka Senani; Muller, Karin; Moldrup, Per
2016-01-01
Soil water repellency (SWR) of soils is a property with significant consequences for agricultural water management, water infiltration, contaminant transport, and for soil erosion. It is caused by the presence of hydrophobic agents on mineral grain surfaces. Soils were samples in different depths......, and the sessile drop method (SDM). The aim to (i) compare the methods, (ii) characterize the soil-water repellency characteristic curves (SWRCC) being SWR as a function of the volumetric soil-water content (θ) or matric potential (ψ), and (iii) find relationships between SWRCC parameters and SOC content. The WDPT...... at three forest sites in Japan and three pasture sites in New Zealand, covering soil organic carbon (SOC) contents between 1 and 26%. The SWR was measured over a range of water contents by three common methods; the water drop penetration time (WDPT) test, the molarity of an ethanol droplet (MED) method...
-
Mestas-Valero, Roger Manuel; Miras-Avalos, Jose Manuel; Paz-González, Antonio
2010-05-01
The direct and continuous assessment of the temporal variation on soil water content is of paramount importance for agricultural practices and, in particular, for the management of water resources. Soil water content is affected by many factors such as topography, particle size, clay and organic matter contents, and tillage systems. There are several techniques to measure or estimate soil water content. Among them, Frequency Domain Reflectometry (FDR) stands out. It is based on measuring the dielectrical constant of the soil environment. This technique allows to describe water dynamics in time and space, to determine the main patterns of soil moisture, the water uptake by roots, the evapotranspiration and the drainage. Therefore, the aim of this study was to assess the daily variation of soil water content in the root-influenced zone in plots devoted to maize and grassland as a function of the soil water volumetric content. The studied site is located in an experimental field of the Centre for Agricultural Research (CIAM) in Mabegondo located in the province of A Coruña, Spain (43°14'N, 8°15'W; 91 masl). The study was carried out from June 2008 to September 2009 in a field devoted to maize (Zea mays, L.) and another field devoted to grassland. The soil of these sites is silt-clay textured. Long-term mean annual temperature and rainfall figures are 13.3 °C and 1288 mm, respectively. During the study period, maize crop was subjected to conventional agricultural practices. A weekly evaluation of the phenological stage of the crop was performed. An EnviroSCAN FDR equipment, comprising six capacitance sensors, was installed in the studied sites following the manufacturer's recommendations, thus assuring a proper contact between the probe and the soil. Soil water content in the root-influenced zone (40 cm depth in grassland and 60 cm depth in maize were considered) was hourly monitored in 20 cm ranges (0-20 cm, 20-40 cm, and 40-60 cm) using FDR. Evaluations were
-
Samarajeewa, A D; Glasauer, S M; Lauzon, J D; O'Halloran, I P; Parkin, Gary W; Dunfield, K E
2012-05-01
A 2 year field experiment evaluated liquid manure application methods on the movement of manure-borne pathogens (Salmonella sp.) and indicator bacteria (Escherichia coli and Clostridium perfringens) to subsurface water. A combination of application methods including surface application, pre-application tillage, and post-application incorporation were applied in a randomized complete block design on an instrumented field site in spring 2007 and 2008. Tile and shallow groundwater were sampled immediately after manure application and after rainfall events. Bacterial enumeration from water samples showed that the surface-applied manure resulted in the highest concentration of E. coli in tile drainage water. Pre-tillage significantly (p tile water and to shallow groundwater within 3 days after manure application (DAM) in 2008 and within 10 DAM in 2007. Pre-tillage also decreased the occurrence of Salmonella sp. in tile water samples. Indicator bacteria and pathogens reached nondetectable levels within 50 DAM. The results suggest that tillage before application of liquid swine manure can minimize the movement of bacteria to tile and groundwater, but is effective only for the drainage events immediately after manure application or initial rainfall-associated drainage flows. Furthermore, the study highlights the strong association between bacterial concentrations in subsurface waters and rainfall timing and volume after manure application.
-
Assessment of soil hydrology variability of a new weighing lysimeter facility
Brown, S. E.; Wagner-Riddle, C.; Berg, A. A.
2017-12-01
Diversifying annual crop rotations is a strategy that mimics natural ecosystems and is postulated to increase agricultural resilience to climate change, soil quality and provision of soil ecosystem services. However, diverse cropping systems could increase soil mineral N levels and lead to greater leaching and/or N2O emissions; which raises the questions: (i) are diverse cropping systems actually beneficial for air and water quality? (ii) what are the trade-offs between soil, water, and air quality upon implementing a diverse cropping rotation? It can be difficult to fully evaluate the interactions between the two N-pollution pathways simultaneously in traditional field studies as drainage is largely unconstrained. Weighing lysimeters solve this issue by providing a closed system to measure N outputs via drainage and soil gas fluxes. A set of 18 weighting lysimeters were installed in Elora, Ontario, Canada in May 2016, to establish a long-term study of N-leaching and greenhouse gas emission from traditional and diverse cropping rotations for two different soil types. Each lysimeter is equipped with an automated chamber for continuous measurement of soil N2O and CO2 fluxes. A full characterization of variations of physical properties that may affect GHG emissions and N-leaching (e.g., soil temperature, moisture, drainage and evapotranspiration rates) amongst the lysimeters is required prior to application and assessment of the management treatments. Novel techniques such as wavelet analysis is required as standard statistical analyses are not applicable to the time series data. A full description of the lysimeters will be presented along with results of the characterization.
-
Energy Technology Data Exchange (ETDEWEB)
Aranda, Suzan [Department of Geological Sciences, University of Texas at El Paso, El Paso, TX 79968 (United States); Borrok, David M., E-mail: dborrok@utep.edu [Department of Geological Sciences, University of Texas at El Paso, El Paso, TX 79968 (United States); Wanty, Richard B. [US Geological Survey, MS 964d, Denver Federal Center, Denver, CO 80225 (United States); Balistrieri, Laurie S. [U.S. Geological Survey, University of Washington, School of Oceanography, Seattle, WA 98195 (United States)
2012-03-15
The pollution of natural waters with metals derived from the oxidation of sulfide minerals like pyrite is a global environmental problem. However, the metal loading pathways and transport mechanisms associated with acid rock drainage reactions are often difficult to characterize using bulk chemical data alone. In this study, we evaluated the use of zinc (Zn) isotopes to complement traditional geochemical tools in the investigation of contaminated waters at the former Waldorf mining site in the Rocky Mountains, Colorado, U.S.A. Geochemical signatures and statistical analysis helped in identifying two primary metal loading pathways at the Waldorf site. The first was characterized by a circumneutral pH, high alkalinity, and high Zn/Cd ratios. The second was characterized by acidic pHs and low Zn/Cd ratios. Zinc isotope signatures in surface water samples collected across the site were remarkably similar (the {delta}{sup 66}Zn, relative to JMC 3-0749-L, for most samples ranged from 0.20 to 0.30 Per-Mille-Sign {+-} 0.09 Per-Mille-Sign 2{sigma}). This probably suggests that the ultimate source of Zn is consistent across the Waldorf site, regardless of the metal loading pathway. The {delta}{sup 66}Zn of pore water samples collected within a nearby metal-impacted wetland area, however, were more variable, ranging from 0.20 to 0.80 Per-Mille-Sign {+-} 0.09 Per-Mille-Sign 2{sigma}. Here the Zn isotopes seemed to reflect differences in groundwater flow pathways. However, a host of secondary processes might also have impacted Zn isotopes, including adsorption of Zn onto soil components, complexation of Zn with dissolved organic matter, uptake of Zn into plants, and the precipitation of Zn during the formation of reduced sulfur species. Zinc isotope analysis proved useful in this study; however, the utility of this isotopic tool would improve considerably with the addition of a comprehensive experimental foundation for interpreting the complex isotopic relationships found in
-
Directory of Open Access Journals (Sweden)
J. I. L. Morison
2013-02-01
Full Text Available The effect of tree (lodgepole pine planting with and without intensive drainage on soil greenhouse gas (GHG fluxes was assessed after 45 yr at a raised peatbog in West Flanders Moss, central Scotland. Fluxes of CO2 CH4 and N2O from the soil were monitored over a 2-yr period every 2 to 4 weeks using the static opaque chamber method in a randomised experimental block trial with the following treatments: drained and planted (DP, undrained and planted (uDP, undrained and unplanted (uDuP and for reference also from an adjoining near-pristine area of bog at East Flanders Moss (n-pris. There was a strong seasonal pattern in both CO2 and CH4 effluxes which were significantly higher in late spring and summer months because of warmer temperatures. Effluxes of N2O were low and no significant differences were observed between the treatments. Annual CH4 emissions increased with the proximity of the water table to the soil surface across treatments in the order: DP 4 m−2 yr−1, respectively. For CO2, effluxes increased in the order uDP 2 m−2 yr−1, respectively. CO2 effluxes dominated the total net GHG emission, calculated using the global warming potential (GWP of the three GHGs for each treatment (76–98%, and only in the n-pris site was CH4 a substantial contribution (23%. Based on soil effluxes only, the near pristine (n-pris peatbog had 43% higher total net GHG emission compared with the DP treatment because of high CH4 effluxes and the DP treatment had 33% higher total net emission compared with the uDP because drainage increased CO2 effluxes. Restoration is likely to increase CH4 emissions, but reduce CO2 effluxes. Our study suggests that if estimates of CO2 uptake by vegetation from similar peatbog sites were included, the total net GHG emission of restored peatbog would still be higher than that of the peatbog with trees.
-
International Nuclear Information System (INIS)
Grotehusmann, D.; Rohlfing, R.; Weyer, G.; Dittrich, D.; Gowik, P.; Pernak, P.
1991-01-01
This bibliographic study is part of the BMFT intergrated project ''Possibilitiis and limits of [ drainage in consederation of the soil and groundwater protection''. Subjects: Environmental relevance and general distribution of organic pollutants; organic pollutants in rain water, soil, and groundwater; fate of organic pollutants in soil; environmental relevance of heavy metals in soil, rain water, and runof; fate of heavy metals in the unsaturated soil rare. (orig./BBR) [de
-
International Nuclear Information System (INIS)
Li, X.; Sawatsky, N.
1995-01-01
Much effort has been focused on defining the end-point of bioremediated soils by chemical analysis (Alberta Tier 1 or CCME Guideline for Contaminated Soils) or toxicity tests. However, these tests do not completely assess the soil quality, or the capability of soil to support plant growth after bioremediation. This study compared barley (Hordeum vulgare) growth on: (i) non-contaminated, agricultural topsoil, (2) oil-contaminated soil (4% total extractable hydrocarbons, or TEH), and (3) oil-contaminated soil treated by bioremediation (< 2% TEH). Soil physical properties including water retention, water uptake, and water repellence were measured. The results indicated that the growth of barley was significantly reduced by oil-contamination of agricultural topsoil. Furthermore, bioremediation did not improve the barley yield. The lack of effects from bioremediation was attributed to development of water repellence in hydrocarbon contaminated soils. There seemed to be a critical water content around 18% to 20% in contaminated soils. Above this value the water uptake by contaminated soil was near that of the agricultural topsoil. For lower water contents, there was a strong divergence in sorptivity between contaminated and agricultural topsoil. For these soils, water availability was likely the single most important parameter controlling plant growth. This parameter should be considered in assessing endpoint of bioremediation for hydrocarbon contaminated soils
-
Hain, C.; Crow, W. T.; Anderson, M. C.; Yilmaz, M. T.
2014-12-01
Atmospheric processes, especially those that occur in the surface and boundary layer, are significantly impacted by soil moisture (SM). Due to the observational gaps in the ground-based monitoring of SM, methodologies have been developed to monitor SM from satellite platforms. While many have focused on microwave methods, observations of thermal infrared land surface temperature (LST) also provides a means of providing SM information. One particular TIR SM method exploits surface flux predictions retrieved from the Atmosphere Land Exchange Inverse (ALEXI) model. ALEXI uses a time-differential measurement of morning LST rise to diagnose the partitioning of net radiation into surface energy fluxes. Here an analysis will be presented to study relationships between three SM products during a multi-year period (2000-2013) from an active/passive microwave dataset (ECV), a TIR-based model (ALEXI), and a land surface model (Noah) over the CONUS. Additionally, all three will be compared against in-situ SM observations from the North American Soil Moisture Database. The second analysis will focus on the use of ALEXI towards diagnosing SM source/sink processes. Traditional soil water balance modeling is based on one-dimensional (vertical-only) water flow, free drainage at the bottom of the soil column, and neglecting ancillary inputs due to processes such as irrigation. However, recent work has highlighted the importance of secondary water source (e.g., irrigation, groundwater extraction, inland wetlands, lateral flows) and sink (e.g., tile drainage in agricultural areas) processes on the partitioning of evaporative and sensible heat fluxes. ALEXI offers a top-down approach for mapping areas where SM source/sink processes have a significant impact on the surface energy balance. Here we present an index, ASSET, that is based on comparisons between ALEXI latent heat flux (LE) estimates and LE predicted by a free-drainage prognostic LSM lacking irrigation, groundwater and tile
-
Isotopic fractionation of soil water during evaporation
Energy Technology Data Exchange (ETDEWEB)
Leopoldo, P R [Faculdade de Ciencias Medicas e Biologicas de Botucatu (Brazil); Salati, E; Matsui, E [Centro de Energia Nuclear na Agricultura, Piracicaba (Brazil)
1974-07-01
The study of the variation of D/H relation in soil water during evaporation is studied. The isotopic fractionation of soil water has been observed in two soils of light and heavy texture. Soil columns were utilized. Soil water was extracted in a system operated under low pressure and the gaseous hydrogen was obtained by decomposition of the water and was analyzed in a GD-150 mass spectrometer for deuterium content. The variation of the delta sub(eta) /sup 0///sub 00/ value during evaporation showed that for water held at potentials below 15 atm, the deuterium content of soil water stays practically constant. For water held at potentials higher than 15 atm, corresponding to the third stage of evaporation, there is a strong tendency of a constant increase of delta sub(eta) /sup 0///sub 00/ of the remaining water.
-
Modelling soil water dynamics and crop water uptake at the field level
Kabat, P.; Feddes, R.A.
1995-01-01
Parametrization approaches to model soil water dynamics and crop water uptake at field level were analysed. Averaging and numerical difficulties in applying numerical soil water flow models to heterogeneous soils are highlighted. Simplified parametrization approaches to the soil water flow, such as
-
Johnson, L. E.; Kim, J.; Cifelli, R.; Chandra, C. V.
2016-12-01
Potential water retention, S, is one of parameters commonly used in hydrologic modeling for soil moisture accounting. Physically, S indicates total amount of water which can be stored in soil and is expressed in units of depth. S can be represented as a change of soil moisture content and in this context is commonly used to estimate direct runoff, especially in the Soil Conservation Service (SCS) curve number (CN) method. Generally, the lumped and the distributed hydrologic models can easily use the SCS-CN method to estimate direct runoff. Changes in potential water retention have been used in previous SCS-CN studies; however, these studies have focused on long-term hydrologic simulations where S is allowed to vary at the daily time scale. While useful for hydrologic events that span multiple days, the resolution is too coarse for short-term applications such as flash flood events where S may not recover its full potential. In this study, a new method for estimating a time-variable potential water retention at hourly time-scales is presented. The methodology is applied for the Napa River basin, California. The streamflow gage at St Helena, located in the upper reaches of the basin, is used as the control gage site to evaluate the model performance as it is has minimal influences by reservoirs and diversions. Rainfall events from 2011 to 2012 are used for estimating the event-based SCS CN to transfer to S. As a result, we have derived the potential water retention curve and it is classified into three sections depending on the relative change in S. The first is a negative slope section arising from the difference in the rate of moving water through the soil column, the second is a zero change section representing the initial recovery the potential water retention, and the third is a positive change section representing the full recovery of the potential water retention. Also, we found that the soil water moving has traffic jam within 24 hours after finished first
-
Kharaka, Y.K.; Schroeder, R.A.; Setmire, J.G.; ,
2003-01-01
We conducted pilot-scale field experiments using nanofiltration membranes to lower the salinity and remove Se, As and other toxic contaminants from saline agricultural wastewater in the Imperial Valley, California, USA. Farmlands in the desert climate (rainfall - 7.4 cm/a) of Imperial Valley cover -200,000 ha that are irrigated with water (-1.7 km3 annually) imported from the Colorado River. The salinity (-850 mg/L) and concentration of Se (-2.5 ??g/L) in the Colorado River water are high and evapotranpiration further concentrates salts in irrigation drainage water, reaching salinities of 3,000-15,000 mg/L TDS and a median Se value of -30 ??g/L. Experiments were conducted with two commercially available nanofiltration membranes, using drainage water of varying composition, and with or without the addition of organic precipitation inhibitors. Results show that these membranes selectively remove more than 95% of Se, SO4, Mo, U and DOC, and -30% of As from this wastewater. Low percentages of Cl, NO3 and HCO3, with enough cations to maintain electrical neutrality also were removed. The product water treated by these membranes comprised more than 90% of the wastewater tested. Results indicate that the treated product water from the Alamo River likely will have less than 0.2 ??g/L Se, salinity of 300-500 mg/L TDS and other chemical concentrations that meet the water quality criteria for irrigation and potable use. Because acceptability is a major issue for providing treated wastewater to urban centers, it may be prudent to use the reclaimed water for irrigation and creation of lower salinity wetlands near the Salton Sea; an equivalent volume of Colorado River water can then be diverted for the use of increasing populations of San Diego and other urban centers in southern California. Nanofiltration membranes yield greater reclaimed-water output and require lower pressure and less pretreatment, and therefore are generally more cost effective than traditional reverse
-
Faecal contamination of water and sediment in the rivers of the Scheldt drainage network.
Ouattara, Nouho Koffi; Passerat, Julien; Servais, Pierre
2011-12-01
The Scheldt watershed is characterized by a high population density, intense industrial activities and intensive agriculture and breeding. A monthly monitoring (n = 16) of the abundance of two faecal indicator bacteria (FIB), Escherichia coli and intestinal enterococci (IE), showed that microbiological water quality of the main rivers of the Scheldt drainage network was poor (median values ranging between 1.4 × 10(3) and 4.0 × 10(5) E. coli (100 mL)( -1) and between 3.4 × 10(2) and 7.6 × 10(4) IE (100 mL)( -1)). The Zenne River downstream from Brussels was particularly contaminated. Glucuronidase activity was measured in parallel and was demonstrated to be a valid surrogate for a rapid evaluation of E. coli concentration in the river waters. FIB were also investigated in the river sediments; their abundance was sometimes high (average values ranging between 2.1 × 10(2) and 3.3 × 10(5) E. coli g( -1) and between 1.0 × 10(2) and 1.7 × 10(5) IE g( -1)) but was not sufficient to contribute significantly to the river water contamination during resuspension events, except for the Scheldt and the Nethe Rivers. FIB were also quantified in representative point sources (wastewater treatment plants) and non-point sources (runoff water and soil leaching on different types of land use) of faecal contamination. The comparison of the respective contribution of point and non-point sources at the scale of the Scheldt watershed showed that point sources were largely predominant.
-
Directory of Open Access Journals (Sweden)
Mikael Larsson
2018-02-01
Full Text Available Mine waters and tailings generated from mining and mineral processing activities often have detrimental impact on the local environment. One example is acid mine drainage, in which sulphides in the mining waste react with water and oxygen to produce an acidic environment that subsequently dissolves host rock minerals from the waste containing toxic metals and trace elements. Copper is one such metal of significance, as it is mined at large volumes in sulphide containing ores. It has strong biocidal activity that greatly affects ecosystems. We have previously reported that glutaraldehyde (GA-crosslinked polyethyleneimine (PEI has strong affinity and selectivity for copper and that diatomaceous earth (DE particles can be modified with the material to form a copper-extraction resin. In this study, the copper uptake of GA-PEI-DE particles was investigated from synthetic and real acid mine drainage samples under different pHs and their copper removal performance was compared with that of selected commercial resins. The results revealed that copper could effectively and preferentially bind to the material at pH 4, and that the copper could be completely eluted by lowering of the pH. In addition, effective copper uptake and elution was demonstrated using real legacy acid mine drainage water from Mount Lyell in Tasmania.
-
International Nuclear Information System (INIS)
1981-01-01
In the Tsuruga Nuclear Power Station, JAPC on the shell on extracted-steam side in B system of No. 4 feed water heater, drain water leakage occurred twice in January, 1981. Then, 61 pCi/g cobalt-60 and 10 pCi/g manganese-54 were detected in soil at the outlet of general drainage on April 17, 1981. The cause was found to be the overflow of radioactive liquid waste in the filter sludge storage tank on March 8, the same year. On-the-spot inspection was subsequently made by the Agency of Natural Resources and Energy on both leakage accidents. The results of inspections are described as follows: the course of leakage accident, and also the measures taken to JAPC in connection with the two leakage accidents. (J.P.N.)
-
Analysis of Irrigation Water Quality at Kadawa Irrigation Project for Improved Productivity
Directory of Open Access Journals (Sweden)
AR Sanda
2014-09-01
Full Text Available In the face of water scarcity and the several negative consequences, such as water wastage, flooding, water logging, soil losses and production losses, conserving the finite amount of fresh water is a must. The quality of irrigation water must therefore be ascertained. The chemical quality of three sources of irrigation water from canal and drainage water, namely drainage water, fresh irrigation water from canal, and drainage/irrigation water mixture, were analyzed from Kadawa irrigation Project for year 2013 and 2014 cropping seasons, with the view to evaluating the potential risks associated with their use in irrigation and hence their suitability or otherwise for irrigation purposes. The analysis revealed that the use of drainage water alone for irrigation may result in problems associated with salinity, while a blend of drainage/irrigation water in the ratio of 1:1 is a viable means of water conservation and a good means of crop production. DOI: http://dx.doi.org/10.3126/ije.v3i3.11082 International Journal of Environment Vol.3(3 2014: 235-240
-
International Nuclear Information System (INIS)
Cabidoche, Y.-M.; Achard, R.; Cattan, P.; Clermont-Dauphin, C.; Massat, F.; Sansoulet, J.
2009-01-01
Chlordecone was applied between 1972 and 1993 in banana fields of the French West Indies. This resulted in long-term pollution of soils and contamination of waters, aquatic biota, and crops. To assess pollution level and duration according to soil type, WISORCH, a leaching model based on first-order desorption kinetics, was developed and run. Its input parameters are soil organic carbon content (SOC) and SOC/water partitioning coefficient (K oc ). It accounts for current chlordecone soil contents and drainage water concentrations. The model was valid for andosol, which indicates that neither physico-chemical nor microbial degradation occurred. Dilution by previous deep tillages makes soil scrapping unrealistic. Lixiviation appeared the main way to reduce pollution. Besides the SOC and rainfall increases, K oc increased from nitisol to ferralsol and then andosol while lixiviation efficiency decreased. Consequently, pollution is bound to last for several decades for nitisol, centuries for ferralsol, and half a millennium for andosol. - Soil and water contamination by chlordecone will persist for several centuries in the French West Indies, because the only decontamination is through leaching by drainage water.
-
Agricultural pesticides in six drainage basins used for public water supply in New Jersey, 1990
Ivahnenko, Tamara; Buxton, D.E.
1994-01-01
A reconnaissance study of six drainage basins in New Jersey was conducted to evaluate the presence of pesticides from agricultural runoff in surface water. In the first phase of the study, surface-water public-supply drainage basins throughout New Jersey that could be affected by pesticide applications were identified by use of a Geographic Information System. Six basins--Lower Mine Hill Reservoir, South Branch of the Raritan River, Main Branch of the Raritan River, Millstone River, Manasquan River, and Matchaponix Brook--were selected as those most likely to be affected by pesticides on the basis of calculated pesticide-application rates and percentage of agricultural land. The second phase of the project was a short-term water-quality reconnaissance of the six drainage basins to determine whether pesticides were present in the surface waters. Twenty-eight surface-water samples (22 water-quality samples, 3 sequentially collected samples, and 3 trip blanks), and 6 samples from water-treatment facilities were collected. Excluding trip blanks, samples from water-treatment facilities, and sequentially collected samples, the pesticides detected in the samples and the percentage of samples in which they were detected, were as follows: atrazine and metolachlor, 86 percent; alachlor, 55 percent; simazine, 45 percent; diazinon, 27 percent; cyanazine and carbaryl, 23 percent; linuron and isophenfos, 9 percent; and chlorpyrifos, 5 percent.Diazinon, detected in one stormflow sample collected from Matchaponix Brook on August 6, 1990, was the only compound to exceed the U.S. Environmental Protection Agency's recommended Lifetime Health Advisory Limit. Correlation between ranked metolachlor concentrations and ranked flow rates was high, and 25 percent of the variance in metolachlor concentrations can be attributed to variations in flow rate. Pesticide residues were detected in samples of pretreated and treated water from water-treatment facilities. Concentrations of all
-
Enrichment of Arsenic in Surface Water, Stream Sediments and Soils in Tibet.
Li, Shehong; Wang, Mingguo; Yang, Qiang; Wang, Hui; Zhu, Jianming; Zheng, Baoshan; Zheng, Yan
2013-12-01
Groundwater in sedimentary deposits in China, Southern, and Southeast Asia down gradient from the Tibetan plateau contain elevated As concentrations on a regional scale. To ascertain the possibility of source region As enrichment, samples of water (n=86), stream sediment (n=77) and soil (n=73) were collected from the Singe Tsangpo (upstream of the Indus River), Yarlung Tsangpo (upstream of the Brahmaputra River) and other drainage basins in Tibet in June of 2008. The average arsenic concentration in stream waters, sediments and soils was 58±70 μg/L (n=39, range 2-252 μg/L), 42±40 mg/kg (n=37, range 12-227 mg/kg), and 44±27mg/kg (n=28, range 12-84 mg/kg) respectively for the Singe Tsangpo and was 11±17 μg/L (n=30, range 2-83 μg/L), 28±11 mg/kg (n=28, range 2-61 mg/kg), and 30±34 mg/kg (n=21, range 6-173 mg/kg) respectively for the Yarlung Tsangpo. A dug well contained 195 μg/L of As. In addition to elevated As levels in surface and shallow groundwater of Tibet, hot spring and alkaline salt lake waters displayed very high As levels, reaching a maximum value of 5,985 μg/L and 10,626 μg/L As, respectively. The positive correlation between [As] and [Na]+[K] in stream waters indicates that these surface water arsenic enrichments are linked to the hot springs and/or salt lakes. Further, 24% of As in stream sediment is reductively leachable, with bulk As displaying a positive correlation with stream water As, suggesting sorption from stream water. In contrast, the fraction of reductively leachable As is negligible for soils and several rock samples, suggesting that As in them are associated with unweathered minerals. Whether the pronounced As anomaly found in Tibet affects the sedimentary As content in deltas downstream or not requires further study.
-
Three Principles of Water Flow in Soils
Guo, L.; Lin, H.
2016-12-01
Knowledge of water flow in soils is crucial to understanding terrestrial hydrological cycle, surface energy balance, biogeochemical dynamics, ecosystem services, contaminant transport, and many other Critical Zone processes. However, due to the complex and dynamic nature of non-uniform flow, reconstruction and prediction of water flow in natural soils remain challenging. This study synthesizes three principles of water flow in soils that can improve modeling water flow in soils of various complexity. The first principle, known as the Darcy's law, came to light in the 19th century and suggested a linear relationship between water flux density and hydraulic gradient, which was modified by Buckingham for unsaturated soils. Combining mass balance and the Buckingham-Darcy's law, L.A. Richards quantitatively described soil water change with space and time, i.e., Richards equation. The second principle was proposed by L.A. Richards in the 20th century, which described the minimum pressure potential needed to overcome surface tension of fluid and initiate water flow through soil-air interface. This study extends this principle to encompass soil hydrologic phenomena related to varied interfaces and microscopic features and provides a more cohesive explanation of hysteresis, hydrophobicity, and threshold behavior when water moves through layered soils. The third principle is emerging in the 21st century, which highlights the complex and evolving flow networks embedded in heterogeneous soils. This principle is summarized as: Water moves non-uniformly in natural soils with a dual-flow regime, i.e., it follows the least-resistant or preferred paths when "pushed" (e.g., by storms) or "attracted" (e.g., by plants) or "restricted" (e.g., by bedrock), but moves diffusively into the matrix when "relaxed" (e.g., at rest) or "touched" (e.g., adsorption). The first principle is a macroscopic view of steady-state water flow, the second principle is a microscopic view of interface
-
Hydraulic conductivity of Red-Yellow Podzolic Soil from Zona da Mata in Pernambuco State, Brazil
International Nuclear Information System (INIS)
M. Netto, Andre; Antonino, Antonio C.D.; Dall'Olio, Attilio; Carneiro, Clemente J.G.; Audry, Pierre
1997-01-01
The determination of the hydraulic conductivity of a Red-Yellow Podzolic Soil was carried out during an experiment in a plot measuring 3,5 m x 3,5 m at the Experimental Station of Itapirema, Goiania, in the State of Pernambuco. The internal drainage method was used to obtain the hydraulic conductivity as a function of soil water content, K (THETA), in there characteristic horizons of the soil. In relation to the methodological aspects, processing of data from internal drainage experiments, including the initial phase of fast drainage, the adjustment of the required parameters, it is necessary to use functions that reproduce the distinct transition between the fast and slow phases of drainage. From all five tested functions, those of power sum of two exponentials and sum of three exponentials, especially this last one, adjusted well to this distinct transition. Three characteristic horizons of the Red-yellow Podzolic Soil were investigated for hydraulic conductivity. The sandy a horizon with large pores, has a high conductivity while the B1t horizon, with massive structure and few visible pores, has a low infiltration rate. The hydraulic dynamics of the B2 horizon is more complex due to its heterogeneity. The precise characterization of the A and B1t, horizons, which are the most important to agriculture and soil conservation makes it possible to elaborate numeric simulation models of the water transference process in the superficial horizons of this type of soil. (author). 11 refs., 3 figs., 1 tab
-
Soil water diffusivity as a function of water content and time
International Nuclear Information System (INIS)
Guerrini, I.A.
1976-04-01
The soil-water diffusivity has been studied as a function of water content and time. From the idea of studying the horizontal movement of water in swelling soils, a simple formulation has been achieved which allows for the diffusivity, water content dependency and time dependency, to be estimated, not only of this kind of soil, but for any other soil as well. It was observed that the internal rearrangement of soil particles is a more important phenomenon than swelling, being responsible for time dependency. The method 2γ is utilized, which makes it possible to simultaneously determine the water content and density, point by point, in a soil column. The diffusivity data thus obtained are compared to those obtained when time dependency is not considered. Finally, a new soil parameter, α, is introduced and the values obtained agrees with the internal rearrangment assumption and time dependency for diffusivity (Author) [pt
-
Changes in water quality of a small urban river triggered by deep drainage of a construction site
Directory of Open Access Journals (Sweden)
Bartnik Adam
2016-12-01
Full Text Available The paper presents the results of the monitoring of the selected physicochemical properties of the Jasień River waters (in Łódź, the third biggest city of Poland and their changes under the influence of drainage of a railway station Łódź Fabryczna construction site. Even 25 years ago the Jasień River was a receiver for the sewage from the Łódź textile factories. The drainage of the excavations and disposal of the water into the Jasień River was started on January 2014 and changed stable hydrological, physical and chemical regime of the river once again. In a consequence, average monthly flows exceeded the Jasień River flow in its upper section by six times, and at the beginning by even ten times. Chloride concentration was systematically growing over the study period. This growth and higher water pH were probably associated with increasing level of contaminants in the discharged water and its gradually decreasing uptake. Average annual water temperature increased and a decrease in its amplitude was observed. The annual conductivity and pH patterns became more uniform and the changes in pH followed a clear trend of monthly changes. Water turbidity increased by two times and during summer floods this parameter was often even a few times higher than before the drainage commenced. Chlorides improved water conductance and sodium and potassium increased basicity.
-
Henine, Hocine; Tournebize, Julien; Laurent, Gourdol; Christophe, Hissler; Cournede, Paul-Henry; Clement, Remi
2017-04-01
framework to predict the soil water content distribution and the results were compared to initial simulations (Hydrus results). We obtained more reliable water content specialization models when using the BME method. The presented approach integrates ERT and TDR measurements, and results demonstrate that its use significantly improves the spatial distribution of water content estimations. The approach will be applied to the experimental dataset collected at the Boissy le Châtel site where ERT data were collected daily during one hydrological year, using Syscal pro 48 electrodes (with a financial support of Equipex-Critex) and 10 TDR probes were used to monitor water content variation. Hourly hydrological survey (tile drainage discharge, precipitation, evapotranspiration variables and water table depth) were conducted at the same site. Data analysis and the application of geostatistical framework on the experimental dataset of 2015-2016 show satisfactory results and are reliable with the hydrological behavior of the study site.
-
Stochastic estimation of plant-available soil water under fluctuating water table depths
Or, Dani; Groeneveld, David P.
1994-12-01
Preservation of native valley-floor phreatophytes while pumping groundwater for export from Owens Valley, California, requires reliable predictions of plant water use. These predictions are compared with stored soil water within well field regions and serve as a basis for managing groundwater resources. Soil water measurement errors, variable recharge, unpredictable climatic conditions affecting plant water use, and modeling errors make soil water predictions uncertain and error-prone. We developed and tested a scheme based on soil water balance coupled with implementation of Kalman filtering (KF) for (1) providing physically based soil water storage predictions with prediction errors projected from the statistics of the various inputs, and (2) reducing the overall uncertainty in both estimates and predictions. The proposed KF-based scheme was tested using experimental data collected at a location on the Owens Valley floor where the water table was artificially lowered by groundwater pumping and later allowed to recover. Vegetation composition and per cent cover, climatic data, and soil water information were collected and used for developing a soil water balance. Predictions and updates of soil water storage under different types of vegetation were obtained for a period of 5 years. The main results show that: (1) the proposed predictive model provides reliable and resilient soil water estimates under a wide range of external conditions; (2) the predicted soil water storage and the error bounds provided by the model offer a realistic and rational basis for decisions such as when to curtail well field operation to ensure plant survival. The predictive model offers a practical means for accommodating simple aspects of spatial variability by considering the additional source of uncertainty as part of modeling or measurement uncertainty.
-
Energy Technology Data Exchange (ETDEWEB)
Saarinen, T.
2013-06-01
This thesis examines temporal and spatial variations in the status of different rivers and streams of western Finland in terms of acidity and sources of acid load derived from the catchment area. It also examines the monitoring of acid runoff water derived from maintenance drainage in peatland forestry and suggests potential mitigation methods. A total of 17 river basins of different sizes in western Finland were selected for study, including rivers affected by both drainage of agricultural AS soils and forested peatlands. Old data from 1911-1931 were available, but most data were from the 1960s onwards and were taken from the HERTTA database. During 2009-2011, pH and conductivity measurements and water sampling were conducted. Biological monitoring for ecological classification was conducted in the Sanginjoki river system during 2008 and 2009. Three peatland forestry sites were selected to study acid leaching via pH and EC measurements and water sampling. Fluctuations in groundwater level in different drainage conditions were simulated and acid leaching was investigated in laboratory experiments in order to replicate a situation where the groundwater level drops and allows oxidation of sulphidic materials. It was found that river pH decreased and metal concentrations increased with runoff. The highest acidity observed coincided with periods of intense drainage in the 1970s and after dry summers in the past decade. Together with pH, electric conductivity and sulphate in river water were identified as suitable indicators of AS soils in a catchment, because they directly respond to acid leaching derived from AS soils. Acidity derived from organic acids was clearly observed in catchments dominated by forested peatlands and wetlands. Temporal and spatial variations in ecological status were observed, but monitoring at whole-catchment scale and during consecutive years is needed to increase the reliability of the results. Simulations on the potential effects of
-
Directory of Open Access Journals (Sweden)
Sung-Min Kim
2018-05-01
Full Text Available Cessation of dewatering following underground mine closure typically results in groundwater rebound, because mine voids and surrounding strata undergo flooding up to the levels of the decant points, such as shafts and drifts. SIMPL (Simplified groundwater program In Mine workings using the Pipe equation and Lumped parameter model, a simplified lumped parameter model-based program for predicting groundwater levels in abandoned mines, is presented herein. The program comprises a simulation engine module, 3D visualization module, and graphical user interface, which aids data processing, analysis, and visualization of results. The 3D viewer facilitates effective visualization of the predicted groundwater level rebound phenomenon together with a topographic map, mine drift, goaf, and geological properties from borehole data. SIMPL is applied to data from the Dongwon coal mine and Dalsung copper mine in Korea, with strong similarities in simulated and observed results. By considering mine workings and interpond connections, SIMPL can thus be used to effectively analyze and visualize groundwater rebound. In addition, the predictions by SIMPL can be utilized to prevent the surrounding environment (water and soil from being polluted by acid mine drainage.
-
Surface water drainage system. Environmental assessment and finding of no significant impact
International Nuclear Information System (INIS)
1996-05-01
This Environmental Assessment (EA) is written pursuant to the National Environmental Policy Act (NEPA). The document identifies and evaluates the action proposed to correct deficiencies in, and then to maintain, the surface water drainage system serving the Department of Energy's Rocky Flats Environmental Technology Site (Site), located north of Golden, Colorado. Many of the activities proposed would not normally be subject to this level of NEPA documentation. However, in many cases, maintenance of the system has been deferred to the point that wetlands vegetation has become established in some ditches and culverts, creating wetlands. The proposed activities would damage or remove some of these wetlands in order to return the drainage system to the point that it would be able to fully serve its intended function - stormwater control. The Department of Energy (DOE) regulations require that activities affecting environmentally sensitive areas like wetlands be the subject of an EA. Most portions of the surface water drainage system are presently inadequate to convey the runoff from a 100-year storm event. As a result, such an event would cause flooding across much of the Site and possibly threaten the integrity of the dams at the terminal ponds. Severe flooding would not only cause damage to facilities and equipment, but could also facilitate the transport of contaminants from individual hazardous substance sites (IHSSs). Uncontrolled flow through the A- and B-series ponds could cause contaminated sediments to become suspended and carried downstream. Additionally, high velocity flood flows significantly increase erosion losses
-
2010-03-29
... DEPARTMENT OF THE INTERIOR Bureau of Reclamation Central Valley Project Improvement Act, Westlands Water District Drainage Repayment Contract AGENCY: Bureau of Reclamation, Interior. ACTION: Notice of Proposed Repayment Contract. SUMMARY: The Bureau of Reclamation will be initiating negotiations with the...
-
Validation of a spatial–temporal soil water movement and plant water uptake model
HEPPELL, J.
2014-06-01
© 2014, (publisher). All rights reserved. Management and irrigation of plants increasingly relies on accurate mathematical models for the movement of water within unsaturated soils. Current models often use values for water content and soil parameters that are averaged over the soil profile. However, many applications require models to more accurately represent the soil–plant–atmosphere continuum, in particular, water movement and saturation within specific parts of the soil profile. In this paper a mathematical model for water uptake by a plant root system from unsaturated soil is presented. The model provides an estimate of the water content level within the soil at different depths, and the uptake of water by the root system. The model was validated using field data, which include hourly water content values at five different soil depths under a grass/herb cover over 1 year, to obtain a fully calibrated system for plant water uptake with respect to climate conditions. When compared quantitatively to a simple water balance model, the proposed model achieves a better fit to the experimental data due to its ability to vary water content with depth. To accurately model the water content in the soil profile, the soil water retention curve and saturated hydraulic conductivity needed to vary with depth.
-
Controlled laboratory experiments and modeling of vegetative filter strips with shallow water tables
Fox, Garey A.; Muñoz-Carpena, Rafael; Purvis, Rebecca A.
2018-01-01
Natural or planted vegetation at the edge of fields or adjacent to streams, also known as vegetative filter strips (VFS), are commonly used as an environmental mitigation practice for runoff pollution and agrochemical spray drift. The VFS position in lowlands near water bodies often implies the presence of a seasonal shallow water table (WT). In spite of its potential importance, there is limited experimental work that systematically studies the effect of shallow WTs on VFS efficacy. Previous research recently coupled a new physically based algorithm describing infiltration into soils bounded by a water table into the VFS numerical overland flow and transport model, VFSMOD, to simulate VFS dynamics under shallow WT conditions. In this study, we tested the performance of the model against laboratory mesoscale data under controlled conditions. A laboratory soil box (1.0 m wide, 2.0 m long, and 0.7 m deep) was used to simulate a VFS and quantify the influence of shallow WTs on runoff. Experiments included planted Bermuda grass on repacked silt loam and sandy loam soils. A series of experiments were performed including a free drainage case (no WT) and a static shallow water table (0.3-0.4 m below ground surface). For each soil type, this research first calibrated VFSMOD to the observed outflow hydrograph for the free drainage experiments to parameterize the soil hydraulic and vegetation parameters, and then evaluated the model based on outflow hydrographs for the shallow WT experiments. This research used several statistical metrics and a new approach based on hypothesis testing of the Nash-Sutcliffe model efficiency coefficient (NSE) to evaluate model performance. The new VFSMOD routines successfully simulated the outflow hydrographs under both free drainage and shallow WT conditions. Statistical metrics considered the model performance valid with greater than 99.5% probability across all scenarios. This research also simulated the shallow water table experiments with
-
Nocco, M. A.; Kucharik, C. J.; Kraft, G.
2013-12-01
recharge) and by inferring ET through difference, modeling, and gas exchange. In April 2013 prior to planting, we installed 10 passive capillary wick lysimeters below the effective rooting zone (z=100 cm) in potato (n=6) and maize (n=4) cropping systems to collect drainage at a 10-minute time-step under cultivation on Isherwood Farms, a sixth-generation family farm in the Wisconsin Central Sands region. Lysimeters were also instrumented to measure soil moisture and temperature at depth (z=10, 20, 40, 80 cm). Farm operators initiated center-pivot irrigation when soil moisture dropped to approximately 50% of plant available water content. Results show that drainage for May-July 2013 was 43 × 53 mm and 48 × 41 mm in irrigated potato and maize cropping systems, respectively, despite 320 mm of precipitation received during the experimental period, which was 15% above average for this region. Soil moisture consistently fluctuated in response to precipitation/irrigation events at the 10 and 20 cm soil depths, but rarely fluctuated in response to precipitation/irrigation events at the 40 and 80 cm soil depths, supporting the low drainage observed during the growing season. Future work will couple these drainage data to ongoing phenological, micrometeorological, and gas exchange observations in order to infer ET and calculate crop water budgets on a seasonal basis.
-
Pleural fluid drainage: Percutaneous catheter drainage versus surgical chest tube drainage
International Nuclear Information System (INIS)
Illescas, F.F.; Reinhold, C.; Atri, M.; Bret, P.M.
1987-01-01
Over the past 4 years, 55 cases (one transudate, 28 exudates, and 26 empymas) were drained. Surgical chest tubes alone were used in 35 drainages, percutaneous catheters alone in five drainages, and both types in 15 drainages. Percutaneous catheter drainage was successful in 12 of 20 drainages (60%). Surgical tube drainage was successful in 18 of 50 drainages (36%). The success rate for the nonempyema group was 45% with both types of drainage. For the empyema group, the success rate for percutaneous catheter drainage was 66% vs 23% for surgical tube drainage. Seven major complications occurred with surgical tube drainage, but only one major complication occurred with percutaneous catheter drainage. Radiologically guided percutaneous catheter drainage should be the procedure of choice for pleural fluid drainage. It has a higher success rate for empyemas and is associated with less complications
-
Evaluation on the Efficiency of Subsurface Drainage in Chiu-Fen Landslide at Northern Taiwan
Ying, L. Y.; Lin, D. G.
2015-12-01
For administrative district, the Chiu-Fen landslide is situated at northern Taiwan and comes within the jurisdiction of Ruei-Fang district, New Taipei City Government. Chiu-Fen village is a famous spot for sightseeing and tourism in Southeast Asia. In the last decade, for economic purpose, a vast area of slope land in Chiu-Fen area was reclaimed into business and commercial districts. However, due to the complicated geological and hydrological conditions, improper reclamation, and lack of appropriate soil and water conservation facilities, large scale landslides are frequently triggered by typhoon rainfall and causes damages to the transportation and residential building in the community. As a consequence, the government initiated a comprehensive field investigations and remediation plans to stabilize the landslide from 1997 and the remediation works were concentrated on subsurface drainages, namely the application of drainage well (a vertical shaft with multi-level horizontal drainage boreholes). To investigate the efficiency of drainage wells on the landslide, the A1-profile in the landslide which covers the drainage wells W2 and W4 was selected for a series of rainfall seepage and slope stability analyses. In addition, a 48-hrs design rainfall with return period of 25, 50 and 100 years based on the local meteorological data bank was adopted for the analyses. The numerical results indicate the factor safety FS of the three potential sliding surfaces within A1-profile are constantly keeping greater than one (FS > 1.0) and without decreasing with the elapsed time during rainfall. This implies that the subsurface drainage works can drain off the infiltrated rainwater from a high intensity and long duration rainfall and preserve the slope stability of landslides from deterioration. Finally, the efficiency of the drainage wells can be evaluated quantitatively in terms of the time-dependent factor of safety and the pore water pressure distribution on several potential
-
Application of nanofiltration to the treatment of acid mine drainage waters
International Nuclear Information System (INIS)
Bastos, Edna T.R.; Barbosa, Celina C.R.; Oliveira, Elizabeth E.M.; Carvalho, Leonel M. de; Pedro Junior, Antonio; Queiroz, Vanessa B.C. de
2009-01-01
This study investigated the separation of uranium and other elements in high concentrations from acid mine waters at Caldas Uranium Mining, in the southeast of Brazil, using nanofiltration membranes. Nanofiltrarion is widely used in water treatment due to the lower energy requirements and higher yields than reverse osmosis. Separation characteristics are dependent on both the molecular size and charge of the dissolved species in the feed solution as well as membrane properties. In this investigation the potential of nanofiltration to removed dissolved species like uranium from acid mine water drainage was measured. Two composite aromatic polyamide commercially membranes of FilmTec/Dow were tested and it found that uranium rejections of greater than 90% and also showed potential for the separation of aluminum and manganese. (author)
-
Dupree, Jean A.; Crowfoot, Richard M.
2012-01-01
The drainage basin is a fundamental hydrologic entity used for studies of surface-water resources and during planning of water-related projects. Numeric drainage areas published by the U.S. Geological Survey water science centers in Annual Water Data Reports and on the National Water Information Systems (NWIS) Web site are still primarily derived from hard-copy sources and by manual delineation of polygonal basin areas on paper topographic map sheets. To expedite numeric drainage area determinations, the Colorado Water Science Center developed a digital database structure and a delineation methodology based on the hydrologic unit boundaries in the National Watershed Boundary Dataset. This report describes the digital database architecture and delineation methodology and also presents the results of a comparison of the numeric drainage areas derived using this digital methodology with those derived using traditional, non-digital methods. (Please see report for full Abstract)
-
Soil water repellency at old crude oil spill sites
International Nuclear Information System (INIS)
Roy, J.L.
1999-08-01
This thesis presents the current state of knowledge regarding the cause of soil water repellency and characterizes disaggregated nonwettable surface soils found at old crude oil spill sites. Pollution-induced water repellency generally develops following prolonged exposures of soil to liquid- or vapour-phase petroleum hydrocarbons. The condition varies significantly in terms of severity and persistence. Soil water repellency retards plant growth and disturbs the hydrological balance of ecosystems. Disaggregated water-repellent soils are also very susceptible to dispersal by erosion, posing a threat to the productivity of surrounding soils. The author described the probable causes of soil water repellency under the following three main themes: (1) accumulation of hydrophobic organic material in soil, (2) redistribution and re-organisation of this material in soil, and (3) stabilisation of the hydrophobic organic material. This final process is necessary to ensure persistence of induced water repellency symptoms. Petroleum residues as water-repellent substances in weathered nonwettable oil-contaminated soils were also discussed and a hypothesis about soil water repellency was presented which deals with flexible conformation in organic matter coatings. Processes leading to the development of soil water repellency following crude oil contamination were also described. It was determined that soil water repellency is a function of the packing density and the chain conformation of amphiphilic organic molecules in the outermost layer of soil organic matter coatings. This research suggests that the fractional coverage of alkyl chains on soil particle surfaces determines the degree of water repellency that is displayed by soil. It was shown that prompt remediation of some oil-contaminated plots can effectively prevent the development of soil water repellency. 4 refs., 32 tabs., 22 figs., 5 appendices
-
Directory of Open Access Journals (Sweden)
M. G. Hodnett
1997-01-01
Full Text Available Soil water storage was monitored in three landscape elements in the forest (plateau, slope and valley floor over a 3 year period to identify differences in sub-surface hydrological response. Under the plateau and slope, the changes of storage were very similar and there was no indication of surface runoff on the slope. The mean maximum seasonal storage change was 156 mm in the 2 m profile but it was clear that, in the dry season, the forest was able to take up water from below 3.6 m. Soil water availability was low. Soil water storage changes in the valley were dominated by the behaviour of a shallow water table which, in normal years, varied between 0.1 m below the surface at the end of the wet season and 0.8 m at the end of the dry season. Soil water storage changes were small because root uptake was largely replenished by groundwater flow towards the stream. The groundwater behaviour is controlled mainly by the deep drainage from beneath the plateau and slope areas. The groundwater gradient beneath the slope indicated that recharge beneath the plateau and slope commences only after the soil water deficits from the previous dry season have been replenished. Following a wet season with little recharge, the water table fell, ceasing to influence the valley soil water storage, and the stream dried up. The plateau and slope, a zone of very high porosity between 0.4 and 1.1 m, underlain by a less conductive layer, is a probable route for interflow during, and for a few hours after, heavy and prolonged rainfall.
-
DEFF Research Database (Denmark)
Kjærgaard, Charlotte; Heckrath, Goswin Johann; Canga, Eriona
in drainage. The Danish “SUPREME-TECH” project (2010-2016) (www.supreme-tech.dk) aims at providing the scientific basis for developing cost-effective filter technologies for P in agricultural drainage waters. The project studies different approaches of implementing filter technologies including drainage well....... Targeting high risk areas of P loss and applying site-specific measures promises to be a cost-efficient approach. The Danish Commission for Nature and Agriculture has, therefore, now called for a paradigm shift towards targeted, cost-efficient technologies to mitigate site-specific nutrient losses...... environmental threshold values (
-
Aranda, Suzan; Borrok, David M; Wanty, Richard B; Balistrieri, Laurie S
2012-03-15
The pollution of natural waters with metals derived from the oxidation of sulfide minerals like pyrite is a global environmental problem. However, the metal loading pathways and transport mechanisms associated with acid rock drainage reactions are often difficult to characterize using bulk chemical data alone. In this study, we evaluated the use of zinc (Zn) isotopes to complement traditional geochemical tools in the investigation of contaminated waters at the former Waldorf mining site in the Rocky Mountains, Colorado, U.S.A. Geochemical signatures and statistical analysis helped in identifying two primary metal loading pathways at the Waldorf site. The first was characterized by a circumneutral pH, high alkalinity, and high Zn/Cd ratios. The second was characterized by acidic pHs and low Zn/Cd ratios. Zinc isotope signatures in surface water samples collected across the site were remarkably similar (the δ(66)Zn, relative to JMC 3-0749-L, for most samples ranged from 0.20 to 0.30‰±0.09‰ 2σ). This probably suggests that the ultimate source of Zn is consistent across the Waldorf site, regardless of the metal loading pathway. The δ(66)Zn of pore water samples collected within a nearby metal-impacted wetland area, however, were more variable, ranging from 0.20 to 0.80‰±0.09‰ 2σ. Here the Zn isotopes seemed to reflect differences in groundwater flow pathways. However, a host of secondary processes might also have impacted Zn isotopes, including adsorption of Zn onto soil components, complexation of Zn with dissolved organic matter, uptake of Zn into plants, and the precipitation of Zn during the formation of reduced sulfur species. Zinc isotope analysis proved useful in this study; however, the utility of this isotopic tool would improve considerably with the addition of a comprehensive experimental foundation for interpreting the complex isotopic relationships found in soil pore waters. Copyright © 2012 Elsevier B.V. All rights reserved.
-
Taylor, George Fred
1993-01-01
Potential sources of contaminants that could pose a threat to drainage-well inflow and to water in the Floridan aquifer system in southwest Orlando, Florida, were studied between October and December 1990. Drainage wells and public-supply wells were inventoried in a 14-square-mile area, and available data on land use and activities within each drainage well basin were tabulated. Three public-supply wells (tapping the Lower Floridan aquifer) and 38 drainage wells (open to the Upper Floridan aquifer) were located in 17 drainage basins within the study area. The primary sources of drainage-well inflow are lake overflow, street runoff, seepage from the surficial aquifer system, and process-wastewater disposal. Drainage-well inflow from a variety of ares, including resi- dential, commercial, undeveloped, paved, and industrial areas, are potential sources of con- taminants. The four general types of possible contaminants to drainage-well inflow are inorganic chemicals, organic compounds, turbidity, and microbiological contaminants. Potential contami- nant sources include plant nurseries, citrus groves, parking lots, plating companies, auto- motive repair shops, and most commonly, lake- overflow water. Drainage wells provide a pathway for contaminants to enter the Upper Floridan aquifer and there is a potential for contaminants to move downward from the Upper Floridan to the Lower Floridan aquifer.
-
Goran Berndes; Heather Youngs; Maria Victoria Ramos Ballester; Heitor Cantarella; Annette L. Cowie; Graham Jewitt; Luiz Antonio Martinelli; Dan Neary
2015-01-01
Bioenergy production can have positive or negative impacts on soil and water. To best understand these impacts, the effects of bioenergy systems on water and soil resources should be assessed as part of an integrated analysis considering environmental, social and economic dimensions. Bioenergy production systems that are strategically integrated in the landscape to...
-
Prudêncio, Maria Isabel; Valente, Teresa; Marques, Rosa; Sequeira Braga, Maria Amália; Pamplona, Jorge
2015-11-01
Rare earth elements (REE) were used to assess attenuation processes in a passive system for acid mine drainage treatment (Jales, Portugal). Hydrochemical parameters and REE contents in water, soils and sediments were obtained along the treatment system, after summer and winter. A decrease of REE contents in the water resulting from the interaction with limestone after summer occurs; in the wetlands REE are significantly released by the soil particles to the water. After winter, a higher water dynamics favors the AMD treatment effectiveness and performance since REE contents decrease along the system; La and Ce are preferentially sequestered by ochre sludge but released to the water in the wetlands, influencing the REE pattern of the creek water. Thus, REE fractionation occurs in the passive treatment systems and can be used as tracer to follow up and understand the geochemical processes that promote the remediation of AMD. Copyright © 2015 Elsevier Ltd. All rights reserved.
-
The results of the electrochemical clearning of drainage waters
Kabannik, Vasilina; Saeva, Olga
2010-05-01
There is a problem of industrial drains clearing in various branches, but especially sharply in a metal manufacture that is caused by great volumes of the wastewater containing high residual concentration of heavy metals. It is necessary to pay attention to solids in wastes. In a long-term interaction with oxygen of air and natural deposits the acid drainage is often formed and takes out a number of elements with different classes of toxicity to superficial and underground waters. Therefore search of an extraction possibilities for toxic components for a eliminate of their further migration is the big deal. Belov Zink Plant located in the Kemerovo region. During sixty years the factory stably made up to 10 000 tons of zinc annually and in passing up to 30 000 tons H2SO4 processing a blende concentrate. Now the factory has stopped the activity, however, in territory have remained uncontrolledly stored about one million tons of the wastes, presented by slags and ashes. Visually clinker represent coarse-grained sands of the typical slag containing 0.7-15% Zn, 0.3-8.5% Cu, 0.03-0.7% Pb and 2-400 g/t Cd. Besides in tailings the sub-standard sulfuric acid [Bortnikova, etc., 2006] are merged. Acid (рН=3.5) and highsaline waters of a drainage stream with significant concentration sulfate-ion (up to 20 g/l), copper (up to 6 g/l) and zinc (up to 4 g/l), that allows to consider as macrocomponents. A wide number of microcells in drains exceeds maximum concentration limit (MPC) of chemical substances in objects of drinking and community use. The basic chemical forms of present metals (Al, Mn, Zn, Fe, Co, Ni, Pb, Cu) are aquo-ions and sulphatic complexes. Earlier in our laboratory searching of a way of a toxic components concentration downturn in drains of Belov plant - sorptive clearing by natural clays [Gaskova, Kabannik, 2009] and sedimentation of toxic elements on carbonate barrier [Yurkevich, etc., 2008] were done, however the desirable result by virtue of that this
-
Using soil water sensors to improve irrigation management
Irrigation water management has to do with the appropriate application of water to soils, in terms of amounts, rates, and timing to satisfy crop water demands while protecting the soil and water resources from degradation. In this regard, sensors can be used to monitor the soil water status; and som...
-
Prediction of the Soil Water Characteristic from Soil Particle Volume Fractions
DEFF Research Database (Denmark)
Naveed, Muhammad; Møldrup, Per; Tuller, Markus
2012-01-01
Modelling water distribution and flow in partially saturated soils requires knowledge of the soil-water characteristic (SWC). However, measurement of the SWC is challenging and time-consuming, and in some cases not feasible. This study introduces two predictive models (Xw-model and Xw......*-model) for the SWC, derived from readily available soil properties such as texture and bulk density. A total of 46 soils from different horizons at 15 locations across Denmark were used for models evaluation. The Xw-model predicts the volumetric water content as a function of volumetric fines content (organic matter...... (organic matter, clay, silt, fine and coarse sand), variably included in the model depending on the pF value. The volumetric content of a particular soil particle size fraction was included in the model if it was assumed to contribute to the pore size fraction still occupied with water at the given p...
-
Directory of Open Access Journals (Sweden)
Radu Lacatusu
2005-10-01
Full Text Available Urban soil is an material that has been manipulated, disturbed or transported by man’s activities in the urban environment and is used as a medium for plant growth and for constructions. The physical, chemical, and biological properties are generally less favorable as a rooting medium than soil found on the natural landscape. The main characteristics of urban soils are: great vertical and spatial variability; modified soil structure leading to compaction; presence of a surface crust; modified soil reaction, usually elevated; restricted aeration and water drainage; modified abundance of chemical elements, interrupted nutrient cycling and soil organism activity; presence of anthropic materials contaminants and pollutants; modified soil temperature regime. The urbic horizon is designated as U (always capital letter and for indication of processes are used different small letters. It is necessary elaboration a new classification of urban soils for our country.
-
M. L. Kavvas; A. Ercan; J. Polsinelli
2017-01-01
In this study dimensionally consistent governing equations of continuity and motion for transient soil water flow and soil water flux in fractional time and in fractional multiple space dimensions in anisotropic media are developed. Due to the anisotropy in the hydraulic conductivities of natural soils, the soil medium within which the soil water flow occurs is essentially anisotropic. Accordingly, in this study the fractional dimensions in two horizontal and one vertical di...
-
Organic compounds in hot-water-soluble fractions from water repellent soils
Atanassova, Irena; Doerr, Stefan
2014-05-01
Water repellency (WR) is a soil property providing hydrophobic protection and preventing rapid microbial decomposition of organic matter entering the soil with litter or plant residues. Global warming can cause changes in WR, thus influencing water storage and plant productivity. Here we assess two different approaches for analysis of organic compounds composition in hot water extracts from accelerated solvent extraction (ASE) of water repellent soils. Extracts were lyophilized, fractionated on SiO2 (sand) and SPE cartridge, and measured by GC/MS. Dominant compounds were aromatic acids, short chain dicarboxylic acids (C4-C9), sugars, short chain fatty acids (C8-C18), and esters of stearic and palmitic acids. Polar compounds (mainly sugars) were adsorbed on applying SPE clean-up procedure, while esters were highly abundant. In addition to the removal of polar compounds, hydrophobic esters and hydrocarbons (alkanes and alkenes particle wettability and C dynamics in soils. Key words: soil water repellency, hot water soluble carbon (HWSC), GC/MS, hydrophobic compounds
-
Stroud, Jacqueline L; Collins, Richard N
2014-07-15
Anthropogenically disturbed coastal acid sulfate soils along the east coast of Australia, and worldwide, periodically result in the discharge of acid waters containing high concentrations of metals. Identifying priority sites (hotspots) within a catchment for acid sulfate soil remediation activities typically involves long-term monitoring of drainwater chemistry, including the capture of data on unpredictable rain-induced groundwater discharge events. To improve upon this monitoring approach, this study investigated using the water lily (Nymphaea capensis) as a biomonitor of drainage waters to identify hotspots in three acid sulfate soil impacted catchments (83 km(2)) in north-eastern New South Wales, Australia. In one catchment where the location of hotspots was known, water lily lamina concentrations of a suite of metal(loid)s were significantly (photspots revealed within catchment variation of plant metal concentrations up to 70-fold. High resolution maps produced from these results, therefore, provided strong evidence for the location of potential hotspots which were confirmed with measurements of drainwater chemistry during rain-induced groundwater discharge events. Median catchment lily accumulation was ca. 160 mg Al kg(-1) and 1,300 mg Fe kg(-1), with hotspots containing up to 6- and 10-fold higher Al and Fe concentrations. These findings suggest that biomonitoring with N. capensis can be an important tool to rapidly identify priority sites for remediation in acid sulfate soil impacted landscapes. Copyright © 2014 Elsevier B.V. All rights reserved.
-
Huang, Xuexia; Li, Ning; Wu, Qihang; Long, Jianyou; Luo, Dinggui; Zhang, Ping; Yao, Yan; Huang, Xiaowu; Li, Dongmei; Lu, Yayin; Liang, Jianfeng
2016-12-01
The objective of this paper is to assess the influence of irritating paddy fields with acid mine drainage containing thallium (Tl) to rice plant-soil system and potential health risks for local residents. Vertical distribution of Tl, pH, organic matter (OM), and cation exchange capacity (CEC) in 24 paddy soil profiles around Yunfu pyrite mine area was investigated. Rice plant samples were collected from the corresponding soil sampling site. The results showed that Tl concentrations in paddy soils at 0-60 cm depth range from 3.07 to 9.42 mg kg -1 , with a mean of 5.74 mg kg -1 , which were significantly higher than the background value of soil in China (0.58 mg kg -1 ). On the whole, Tl contents in paddy soil profiles increased quickly with soil depth from 0 to 30 cm and decreased slowly with soil depth from 30 to 60 cm. The soil Tl content was significant negatively correlated with soil pH. The mean content of Tl in the root, stem, leaf, and rice was 4.36, 1.83, 2.74, and 1.42 mg kg -1 , respectively, which exceeded the proposed permissible limits for foods and feedstuffs in Germany. The Tl content in various tissues of the rice plants followed the order root > leaf > stem (rice), which suggested that most Tl taken up by rice plants retained in the root, and a little migrated to the leaf, stem, and rice. Correlation analysis showed that Tl content in root was significant positively correlated with Tl content in leaf and rice. The ranges of hazard quotient (HQ) values were 4.08∼24.50 and 3.84∼22.38 for males and females, respectively. Males have higher health risk than females in the same age group. In childhood age groups (2 to <21 years) and adult age groups (21 to <70 years), the highest health risk level was observed in the 11 to 16 age group and 21 to 50 age group, respectively. The findings indicated that regular irrigation with Tl-bearing acid mine drainage led to considerable contamination of Tl in paddy soil and rice plant. Local government
-
Directory of Open Access Journals (Sweden)
Basyarullah Lubis
2017-09-01
Full Text Available In the construction of public facilities and infrastructure attention should always be given to matters that are directly or indirectly related to the construction of such facilities and infrastructure. As in the construction of drainage there are several things that affect it one of which is most often used as a reference in the calculation of drainage channel dimension is maximum rainfall or maximum daily rainfall intensity. Tanjung Selamat is chosen for study because this road is a liaison route for the surrounding community activities and Tanjung Selamat area and Medan city or Pancur Batu District. Therefore it is necessary a review of the existing drainage channel of rapid development that occurred in Jalan Flamboyan Raya of Tanjung Selamat village both residential areas and places of business. This situation reduces the area of water catchment so that water is often abundant and make the existing drainage channel cannot accommodate it. This research is conducted in several stages and with Pearsons Log Distribution Method of Type III which aims to determine the magnitude of the peak flood discharge in a particular repetitive period. Based on the results of research and calculations that have been done know that the amount of existing drainage discharge is smaller than peak flood discharge in the area around Flamboyan Road Raya of Tanjung Selamat village. Other causes of the flooding that occurred in the location where the research that the authors do is human behavior that is not friendly to the environment such as littering haphazardly or into the drainage channel less attention to the maintenance of drainage channels around their dwelling soil-walled conditions so very vulnerable to changes that affect the ability of the channel to drain the water. Equally important is the development around Jalan Flamboyan Raya of Tanjung Selamat village especially the establishment of various buildings either for residences or for business places
-
Correlation Between Cone Penetration Rate And Measured Cone Penetration Parameters In Silty Soils
DEFF Research Database (Denmark)
Poulsen, Rikke; Nielsen, Benjaminn Nordahl; Ibsen, Lars Bo
2013-01-01
This paper shows, how a change in cone penetration rate affects the cone penetration measurements, hence the cone resistance, pore pressure, and sleeve friction in silty soil. The standard rate of penetration is 20 mm/s, and it is generally accepted that undrained penetration occurs in clay while...... drained penetration occurs in sand. When lowering the penetration rate, the soil pore water starts to dissipate and a change in the drainage condition is seen. In intermediate soils such as silty soils, the standard cone penetration rate may result in a drainage condition that could be undrained......, partially or fully drained. However, lowering the penetration rate in silty soils has a great significance because of the soil permeability, and only a small change in penetration rate will result in changed cone penetration measurements. In this paper, analyses will be done on data from 15 field cone...
-
Sedimentation and chemical quality of surface water in the Heart River drainage basin, North Dakota
Maderak, Marion L.
1966-01-01
The Heart River drainage basin of southwestern North Dakota comprises an area of 3,365 square miles and lies within the Missouri Plateau of the Great Plains province. Streamflow of the Heart River and its tributaries during 1949-58 was directly proportional to .the drainage area. After the construction of Heart Butte Dam in 1949 and Dickinson Dam in 1950, the mean annual streamflow near Mandan was decreased an estimated 10 percent by irrigation, evaporation from the two reservoirs, and municipal use. Processes that contribute sediment to the Heart River are mass wasting, advancement of valley heads, and sheet, lateral stream, and gully erosion. In general, glacial deposits, terraces, and bars of Quaternary age are sources of sand and larger sediment, and the rocks of Tertiary age are sources of clay, silt. and sand. The average annual suspended-sediment discharges near Mandan were estimated to be 1,300,000 tons for 1945-49 and 710,000 tons for 1970-58. The percentage composition of ions in water of the Heart River, based on average concentrations in equivalents per million for selected ranges of streamflow, changes with flow and from station to station. During extremely low flows the water contains a large percentage of sodium and about equal percentages of bicarbonate and .sulfate, and during extremely high flows the water contains a large percentage of calcium plus magnesium and bicarbonate. The concentrations, in parts per million, of most of the ions vary inversely with flow. The water in the reservoirs--Edward Arthur Patterson Lake and Lake Tschida--during normal or above-normal runoff is of suitable quality for public use. Generally, because of medium or high salinity hazards, the successful long-term use of Heart River water for irrigation will depend on a moderate amount of leaching, adequate drainage, ,and the growing of crops that have moderate or good salt tolerance.
-
Farmer driven national monitoring of nitrogen concentrations in drainage water in Denmark
Piil, Kristoffer; Lemming, Camilla; Kolind Hvid, Søren; Knudsen, Leif
2014-05-01
Field drains are often considered to short circuit the hydrological cycle in agricultural catchments and lead to an increased risk of nitrogen loss to the environment. Because of increased regulation of agricultural practices due to catchment management plans, resulting from the implementation of the water frame directive, Danish farmers pushed for a large scale monitoring of nitrogen loss from field drains. Therefore, the knowledge centre for agriculture, Denmark, organized a three year campaign where farmers and local agricultural advisory centres collected water samples from field drains three to five times during the winter season. Samples were analysed for nitrate and total nitrogen. Combined, more than 600 drains were monitored over the three years. During the first two years of monitoring, average winter concentrations of total nitrogen ranged from 0.1 mg N L-1 to 31.1 mg N L-1, and the fraction of total nitrogen present as nitrate ranged from 0% to 100%. This variation is much larger than what is observed in the Danish national monitoring and assessment programme, which monitors only a few drains in selected catchments. Statistical analysis revealed that drainage water nitrogen concentrations were significantly correlated to the cropping system and the landscape type (high ground/lowlands/raised seabed) in which the monitored fields were situated. The average total nitrogen concentration was more than 2 mg N L-1 lower on raised seabed than on high ground, and the average fraction of total nitrogen present as nitrate was more than 20% lower. This indicates that substantial nitrate reduction occurs at or above the drain depth on raised sea flats, in particular in the north of Denmark. This inherent nitrogen retention on raised seabed is not taken into account in the current environmental regulation, nor in the first generation catchment management plans. The monitoring program demonstrated large variation in nitrogen concentrations in drainage water, in
-
Field soil-water properties measured through radiation techniques
International Nuclear Information System (INIS)
1984-07-01
This report shows a major effort to make soil physics applicable to the behaviour of the field soils and presents a rich and diverse set of data which are essential for the development of effective soil-water management practices that improve and conserve the quality and quantity of agricultural lands. This piece of research has shown that the neutron moisture meter together with some complementary instruments like tensiometers, can be used not only to measure soil water contents but also be extremely handy to measure soil hydraulic characteristics and soil water flow. It is, however, recognized that hydraulic conductivity is highly sensitive to small changes in soil water content and texture, being extremely variable spatially and temporally
-
Soil physical properties affecting soil erosion in tropical soils
International Nuclear Information System (INIS)
Lobo Lujan, D.
2004-01-01
The total vegetated land area of the earth is about 11,500 hectare. Of this, about 12% is in South America. Of this, about 14% is degraded area. Water erosion, chemical degradation, wind erosion, and physical degradation have been reported as main types of degradation. In South America water erosion is a major process for soil degradation. Nevertheless, water erosion can be a consequence of degradation of the soil structure, especially the functional attributes of soil pores to transmit and retain water, and to facilitate root growth. Climate, soil and topographic characteristics determine runoff and erosion potential from agricultural lands. The main factors causing soil erosion can be divided into three groups: Energy factors: rainfall erosivity, runoff volume, wind strength, relief, slope angle, slope length; Protection factors: population density, plant cover, amenity value (pressure for use) and land management; and resistance factors: soil erodibility, infiltration capacity and soil management. The degree of soil erosion in a particular climatic zone, with particular soils, land use and socioeconomic conditions, will always result from a combination of the above mentioned factors. It is not easy to isolate a single factor. However, the soil physical properties that determine the soil erosion process, because the deterioration of soil physical properties is manifested through interrelated problems of surface sealing, crusting, soil compaction, poor drainage, impeded root growth, excessive runoff and accelerated erosion. When an unprotected soil surface is exposed to the direct impact of raindrops it can produce different responses: Production of smaller aggregates, dispersed particles, particles in suspension and translocation and deposition of particles. When this has occurred, the material is reorganized at the location into a surface seal. Aggregate breakdown under rainfall depends on soil strength and a certain threshold kinetic energy is needed to start
-
DEFF Research Database (Denmark)
Hansen, Lisbet Sneftrup; Borup, Morten; Moller, Arne
2014-01-01
drainage models and reduce a number of unavoidable discrepancies between the model and reality. The latter can be achieved partly by inserting measured water levels from the sewer system into the model. This article describes how deterministic updating of model states in this manner affects a simulation...
-
Mathematical modelling of water and gas transport in layered soil covers for coal ash deposits
Energy Technology Data Exchange (ETDEWEB)
Rasmussen, A; Lindgren, M [Kemakta Consultants Co, Stockholm (SE)
1990-12-17
In the present work the dry deposition alternative is investigated. In particular the design of soil covers is treated theoretically using mathematical models. The soil cover should primarily act as a barrier against infiltrating water. This is done by having soil cover materials with low permeabilities and sloping covers thereby diverting the infiltrating water in the lateral direction. An important design aspect is that overflow should be avoided since this may cause erosional problems. Thus the design of the cover should allow for lateral water flow within the cover. In the present work we use the computer code TRUST for calculating the flow rates and the moisture contents in two layer covers (till on top of clay) for varying conditions. The calculations so far show that the hydraulic conductivity of the clay layer should be smaller than 10{sup -8} m/s. However, for the simulated longer covers (50 m) a lower hydraulic conductivity gives overflow indicating that better lateral drainage must be provided for. This can be done by increasing the thickness or hydraulic conductivity of the till layer. Simulations for different slopes give little impact, while the hydraulic conductivity of the clay layer is of major importance. Gas transport through the soil cover may be of importance if the waste contains pyrite. In the presence of oxygen and water, pyrite is oxidized producing sulphuric acid. The lowered pH will accelerate the leaching of several heavy metals. The transport rate of gas through a porous material is very sensitive to the water content, decreasing rapidly with increasing water content. In the present work a model, where the unsaturated conditions are accounted for, is outlined. A previously developed method for calculating oxygen transport and oxidation rate of pyrite in connection with mine wastes is generalized from 1D to 2D. A sample calculation illustrates the feasibility of the method. (au) (43 refs.).
-
Evaluatiopn of Strategies for Modifying Urban Storm Water Drainage System Using Risk-based Criteria
Directory of Open Access Journals (Sweden)
mahsa soleimani
2016-01-01
Full Text Available Appropriate modification of existing urban storm water drainage networks may help reduce network inundation and flood-borne pollution risks. It will, therefore, be necessary to analyze the risks associated with water quantity and quality during urban flooding before any reconstruction strategies can be identified that are adaptable to, or compatible with, urban sustainable development strategies. In this paper, three network modification strategies are evaluated against the three criteria of network inundation at different sections, flood pollution risks, and modification plan costs. The modification strategies evaluated include the conventional approach of increasing conduit dimensions as well as the two novels swale and bio-retention systems. The strategies are then prioritised using a Multi-Criteria Decision Analysis (MCDA method. The application of the proposed methodology is illustrated in the case study of urban storm water drainage systems in the Golestan City in Tehran Province for which a hydrological and hydraulic simulation model has been developed using the SWMM software. The results show that the swale system is the best strategy with an approximate cost of 20 billion Rials (almost US$ 6 million. Compared to the existing system in operation, the proposed system will be capable of reducing 59% of the quantitative risk of flooding (inundation and 26% of the water quality risk (pollution loads.
-
Water transport in desert alluvial soil
International Nuclear Information System (INIS)
Kearl, P.M.
1982-04-01
Safe storage of radioactive waste buried in an arid alluvial soil requires extensive site characterization of the physical process influencing moisture movement which could act as a transport medium for the migration of radionuclides. The field portion of this study included an infiltration plot instrumented with thermocouple psychrometers and neturon moisture probe access holes. Baseline information shows a zone of higher moisture content at approximately 1.5 m (5 ft) in depth. A sprinkler system simulated a 500-year precipitation event. Results revealed water penetrated the soil to 0.9 m (2.9 ft). Due to the low moisture content, vapor transport was primarily responsible for water movement at this depth. Temperature gradients are substantially responsible for vapor transport by preferentially sorting water-vapor molecules from the surrounding air by using the soil as a molecular sieve. Adsorbed and capillary water vapor pressure increases in response to a temperature increase and releases additional water to the soil pore atmosphere to be diffused away
-
Tarigan, A. P. M.; Rahmad, D.; Sembiring, R. A.; Iskandar, R.
2018-02-01
This paper illustrates an application of Analytical Hierarchy Process (AHP) as a potential decision-making method in water resource management related to drainage rehabilitation. The prioritization problem of urban drainage rehabilitation in Medan City due to limited budget is used as a study case. A hierarchical structure is formed for the prioritization criteria and the alternative drainages to be rehabilitated. Based on the AHP, the prioritization criteria are ranked and a descending-order list of drainage is made in order to select the most favorable drainages to have rehabilitation. A sensitivity analysis is then conducted to check the consistency of the final decisions in case of minor changes in judgements. The results of AHP computed manually are compared with that using the software Expert Choice. It is observed that the top three ranked drainages are consistent, and both results of the AHP methods, calculated manually and performed using Expert Choice, are in agreement. It is hoped that the application of the AHP will help the decision-making process by the city government in the problem of urban drainage rehabilitation.
-
Soil water regime under homogeneous eucalyptus and pine forests
International Nuclear Information System (INIS)
Lima, W.P.; Reichardt, K.
1977-01-01
Measurement of precipitation and monthly soil water content during two consecutive years, in 6-year old plantations of eucalypt and pine, and also in an open plot containing natural herbaceous vegetation, were used to compare the soil water regime of these vegetation covers. Precipitation was measured in the open plot with a recording and a non-recording rain gage. Soil water was assessed by the neutron scattering technique to a depth of 1,80 meters. Results indicate that there was, in general, water available in the soil over the entire period of study in all three vegetation conditions. The annual range of soil water in eucalypt, pine, and in natural herbaceous vegetation was essentially similar. The analysis of the average soil water regime showed that the soil under herbaceous vegetation was, generally, more umid than the soil under eucalypt and pine during the period of soil water recharge (September through February); during the period of soil water depletion, the opposite was true. Collectively, the results permit the conclusion that there were no adverse effects on the soil water regime which could be ascribed to reflorestation with eucalypt or pine, as compared with that observed for the natural herbaceous vegetation [pt
-
Investigations of effective porosity of till by means of a combined soil-moisture/density gauge
International Nuclear Information System (INIS)
Nordberg, L.; Modig, S.
1974-01-01
Effective porosity and processes of saturation and dewatering in till have been investigated. The study was performed in undisturbed till columns, surrounded by ring-shaped excavations filled with sand. The procedure allowed for a raising and lowering of an artificial groundwater level in the till under controlled conditions, which in turn made possible controlled processes of saturation and dewatering. A combined gamma-neutron soil moisture /density gauge was used. The water content was recorded during a period in which water was added to a specially prepared, undisturbed in-situ soil column until a state of saturation was reached. This was followed by a period of induced dewatering by gravity drainage. The drainage was recorded until a steady state> approximately equalling field capacity, was approached (5-16 d). Water contents at saturation are assumed approximately to equal total porosity, having a range of 17.9-32.0% in the investigated till. The intensity of drainage was highest on the first day of dewatering and then diminished with time. A perfectly steady state was never reached. Therefore field capacity is used with indices, indicating the length of time of drainage. Consequently, effective porosity is qualified by the corresponding indices. After 15-16 days of gravity drainage, effective porosity was calculated to be on the average 7.4% at one test plot and 3.4% at another. The difference has been attributed to a corresponding difference in depth to the natural groundwater level; because of the method used a higher groundwater level and capillary fringe may have hampered the complete drainage, resulting in a relatively low value of effective porosity. The investigation is most likely to be applicable in water balance studies, groundwater discharge predictions and various construction and waste-water projects in moraine terrain. (author)
-
Mechanical impedance of soil crusts and water content in loamy soils
Josa March, Ramon; Verdú, Antoni M. C.; Mas, Maria Teresa
2013-04-01
Soil crust development affects soil water dynamics and soil aeration. Soil crusts act as mechanical barriers to fluid flow and, as their mechanical impedance increases with drying, they also become obstacles to seedling emergence. As a consequence, the emergence of seedling cohorts (sensitive seeds) might be reduced. However, this may be of interest to be used as an effective system of weed control. Soil crusting is determined by several factors: soil texture, rain intensity, sedimentation processes, etc. There are different ways to characterize the crusts. One of them is to measure their mechanical impedance (MI), which is linked to their moisture level. In this study, we measured the evolution of the mechanical impedance of crusts formed by three loamy soil types (clay loam, loam and sandy clay loam, USDA) with different soil water contents. The aim of this communication was to establish a mathematical relationship between the crust water content and its MI. A saturated soil paste was prepared and placed in PVC cylinders (50 mm diameter and 10 mm height) arranged on a plastic tray. Previously the plastic tray was sprayed with a hydrophobic liquid to prevent the adherence of samples. The samples on the plastic tray were left to air-dry under laboratory conditions until their IM was measured. To measure IM, a food texture analyzer was used. The equipment incorporates a mobile arm, a load cell to apply force and a probe. The arm moves down vertically at a constant rate and the cylindrical steel probe (4 mm diameter) penetrates the soil sample vertically at a constant rate. The equipment is provided with software to store data (time, vertical distance and force values) at a rate of up to 500 points per second. Water content in crust soil samples was determined as the loss of weight after oven-drying (105°C). From the results, an exponential regression between MI and the water content was obtained (determination coefficient very close to 1). This methodology allows
-
International Nuclear Information System (INIS)
Torre Jorgenson, M; Harden, Jennifer; Manies, Kristen; Kanevskiy, Mikhail; Shur, Yuri; O’Donnell, Jonathan; Wickland, Kim; Striegl, Robert; Ewing, Stephanie; Zhuang Qianlai; Koch, Josh
2013-01-01
The diversity of ecosystems across boreal landscapes, successional changes after disturbance and complicated permafrost histories, present enormous challenges for assessing how vegetation, water and soil carbon may respond to climate change in boreal regions. To address this complexity, we used a chronosequence approach to assess changes in vegetation composition, water storage and soil organic carbon (SOC) stocks along successional gradients within four landscapes: (1) rocky uplands on ice-poor hillside colluvium, (2) silty uplands on extremely ice-rich loess, (3) gravelly–sandy lowlands on ice-poor eolian sand and (4) peaty–silty lowlands on thick ice-rich peat deposits over reworked lowland loess. In rocky uplands, after fire permafrost thawed rapidly due to low ice contents, soils became well drained and SOC stocks decreased slightly. In silty uplands, after fire permafrost persisted, soils remained saturated and SOC decreased slightly. In gravelly–sandy lowlands where permafrost persisted in drier forest soils, loss of deeper permafrost around lakes has allowed recent widespread drainage of lakes that has exposed limnic material with high SOC to aerobic decomposition. In peaty–silty lowlands, 2–4 m of thaw settlement led to fragmented drainage patterns in isolated thermokarst bogs and flooding of soils, and surface soils accumulated new bog peat. We were not able to detect SOC changes in deeper soils, however, due to high variability. Complicated soil stratigraphy revealed that permafrost has repeatedly aggraded and degraded in all landscapes during the Holocene, although in silty uplands only the upper permafrost was affected. Overall, permafrost thaw has led to the reorganization of vegetation, water storage and flow paths, and patterns of SOC accumulation. However, changes have occurred over different timescales among landscapes: over decades in rocky uplands and gravelly–sandy lowlands in response to fire and lake drainage, over decades to
-
Directory of Open Access Journals (Sweden)
Marcus Vinícius Vieitas Ramos
2006-04-01
Full Text Available Sendo as veredas importantes reguladores do equilíbrio dos cursos d'água da região dos cerrados, objetivou-se caracterizar e comparar solo, água e tipo de uso destes ambientes nas superfícies geomórficas Chapadas e Arenito Bauru. Foram coletadas amostras dos solos e da água, das veredas. O uso foi analisado por observações de campo e entrevistas com proprietários rurais. As veredas apresentam solos hidromórficos em toda a sua extensão, havendo maior homogeneidade no Bauru. Do terço superior em direção ao terço inferior, a drenagem piora, e são maiores os teores de argila, matéria orgânica e fertilidade natural. As veredas do Bauru apresentam melhor drenagem, maior fertilidade, menores teores de matéria orgânica de argila. A água enquadrou-se na classe 4, principalmente em função da cor, acompanhando variações do teor de matéria orgânica do solo. Nas veredas da Chapada, o uso da água na agricultura gera risco de contaminação ambiental, enquanto no Bauru, é comum seu represamento para dessedentação do gado. Os solos das veredas do Bauru são utilizados com freqüência para pastagem nativa, os da Chapada, são mantidos sem uso. A cor preta ou cinzenta dos solos é um atributo de fácil identificação no campo para delimitar tais ambientes.Being the veredas (swampy plains between hills and rivers important regulators of water courses equilibrium at the cerrado region, we aimed to characterize and to compare soils, water and use type of these environments in Chapada and Arenito Bauru geomorphic surfaces. Soil and water samples were collected from the veredas. The use was analysed through field observations and interviews with farmers. The veredas present hydromorphic soils in all their extension, occurring higher homogeneity in Bauru. From the superior to the inferior part, the drainage gets worse, and the clay contents, organic matter and natural fertility increase. The Bauru veredas present better drainage
-
Directory of Open Access Journals (Sweden)
Mayra Abril
2018-01-01
Full Text Available Through preparation of multicomponent nanoparticles (MCNPs using ferric chloride (FeCl3, sodium sulfate (Na2SO4, and the extract of mortiño fruit (Vaccinium floribundum Kunth, we dramatically improved the removal/immobilization of heavy metals from water and in soils. As-prepared nanoparticles were spherical measuring approximately 12 nm in diameter and contained iron oxides and iron sulfides in the crystal structure. Removal of copper and zinc from water using MCNPs showed high efficiencies (>99% at pH above 6 and a ratio of 0.5 mL of the extract:10 mL 0.5 M FeCl3·6H2O : 10 mL 0.035 M Na2SO4. The physisorption process followed by chemisorption was regarded as the removal mechanism of Cu and Zn from water. While, when MCNPs were used to treat soils contaminated with heavy metals, more than 95% of immobilization was accomplished for all metals. Nevertheless, the distribution of the metallic elements changed in the soil fractions after treatment. Results indicate that immobilization of metals after the injection of nanoparticles into soils was effective. Metals did not leach out when soils were drained with rain, drinking, and deionized water but fairly leached out under acidic water drainage.
-
Effectiveness of oat and rye cover crops in reducing nitrate losses in drainage water
A significant portion of the NO3 from agricultural fields that contaminates surface waters in the Midwest Corn Belt is transported to streams or rivers by subsurface drainage systems or “tiles”. Previous research has shown that N fertilizer management alone is not sufficient for reducing NO3 concent...
-
Soil-Water Characteristic Curves of Red Clay treated by Ionic Soil Stabilizer
Cui, D.; Xiang, W.
2009-12-01
The relationship of red clay particle with water is an important factor to produce geological disaster and environmental damage. In order to reduce the role of adsorbed water of red clay in WuHan, Ionic Soil Stabilizer (ISS) was used to treat the red clay. Soil Moisture Equipment made in U.S.A was used to measure soil-water characteristic curve of red clay both in natural and stabilized conditions in the suction range of 0-500kPa. The SWCC results were used to interpret the red clay behavior due to stabilizer treatment. In addition, relationship were compared between the basic soil and stabilizer properties such as water content, dry density, liquid limit, plastic limit, moisture absorption rate and stabilizer dosages. The analysis showed that the particle density and specific surface area increase, the dehydration rate slows and the thickness of water film thins after treatment with Ionic Soil Stabilizer. After treatment with the ISS, the geological disasters caused by the adsorbed water of red clay can be effectively inhibited.
-
Directory of Open Access Journals (Sweden)
Paolo Bazzoffi
2011-08-01
Full Text Available The agronomic measures made obligatory by the cross-compliance Standard Temporary measures for runoff water control on sloping land included in the Ministry of Agricultural, Food and Forestry Policies (MiPAAF decree on cross compliance until 2008, and by Standard 1.1 Creation of temporary ditches for the prevention of soil erosion in the 2009 decree, certainly appear to be useful for the control of soil erosion and runoff. The efficacy of temporary drainage ditches and of grass strips in controlling runoff and erosion has been demonstrated in trials conducted in field test plots in Italy. When level temporary drainage ditches are correctly built, namely with an inclination of not more than 2.5% in relation to the maximum hillslope gradient, they allow the suspended sediment eroded upstream to settle in the ditches, retaining the material carried away on the slope and, as a result, reducing the quantity of sediment delivered to the hydrographic network. In particular, among all the results, the erosion and runoff data in a trial conducted in Guiglia (Modena showed that in corn plots, temporary drainage ditches reduced soil erosion by 94%, from 14.4 Mg ha-1 year-1 (above the limit established by the NRCS-USDA of 11.2 Mg ha-1 year-1 to 0.8 Mg ha-1 year-1 (within the NRCS limit and also within the more restrictive limit established by the OECD of 6.0 Mg ha-1 year-1. With respect to the grass buffer strips the most significant research was carried out in Volterra. This research demonstrated their efficacy in reducing erosion from 8.15 Mg ha-1 to 1.6 Mg ha-1, which is approximately 5 times less than the erosion observed on bare soil. The effectiveness of temporary drainage ditches was also assessed through the application of the Revised Universal Soil Loss Equation (RUSLE erosion model to 60 areas under the control of the Agency for Agricultural Payments (AGEA in 2009, comparing the risk of erosion in these sample areas by simulating the presence and
-
Use of neutron water and gamma density gauges in soil water studies
International Nuclear Information System (INIS)
Kirda, C.
1990-01-01
Irrigation practices should be improved to increase effective use of water and thereby increasing irrigated areas as well as securing soil productivity under irrigated agriculture. Under dry farming systems of rainfed agriculture, different tillage practices should be tested for improved soil water conservation and rain harvesting. The research work addressing the above mentioned problems requires methods to measure soil water content accurately and conveniently. In the following article, the methods which are currently used to measure field soil water content were discussed. 34 refs, 13 figs, 13 tabs
-
Hargitai, H. I.; Gulick, V. C.; Glines, N. H.
2017-09-01
The Navua Valles are systems of paleodrainages located north of Dao Vallis, which empty into Hellas Planitia, the largest impact basin on Mars. In this study, we mapped and characterized the Navua Valles Region's individual drainage systems, including drainages along the southwestern flank of Hadriacus Mons, and one valley network from the same source as Navua Valles but flowing in the opposite direction. The major drainage systems share morphological characteristics common to both outflow channels and valley networks. The slopes in this region are dissected by two major Navua drainage systems (here Navua A* and B*) and several shorter, sub-parallel valleys formed on the highest gradient (approximately 20 m/km [1.15°]) slopes, at the lowest part of Hellas Basin's rim. The two major drainage systems originate in the highlands, and empty into the basin. Our mapping suggests that water in Navua Valles reached the basin floor in a complicated descent and included several episodes of surface ponding, surface runoff, infiltration, subsurface flow and subsequent outflow. The most prominent channel system, Navua A, forms a repetitive sequence of deep incision into bedrock, followed by a transition into broad channels in erodible materials, and then into unconfined deposits. This successive erosion-transport-deposition sequence continues to repeat along the valley's entire length forming a discontinuous pattern that is consistent with classical fluvial process models. The channels cut into volcanic plains likely emplaced from the formation of Tyrrhenus and Hadriacus Montes. The dendritic source valleys of Navua A originate from the rim of a highland crater while the rest of this subsystem consists of a single, discontinuous channel which is consistent with a single water source zone that likely supplied water for all channels downslope. These drainages may have formed as discontinuous channels, revealing the potential existence of subsurface drainage pathways located
-
Characterization of field-measured soil-water properties
International Nuclear Information System (INIS)
Nielsen, D.R.; Reichardt, K.; Wierenga, P.J.
1983-01-01
As part of a five-year co-ordinated research programme of the International Atomic Energy Agency, the Use of Radiation and Isotope Techniques in Studies of Soil-Water Regimes, soil physicists examined soil-water properties of one or two field sites in 11 different countries (Brazil, Belgium, Cyprus, Chile, Israel, Japan, Madagascar, Nigeria, Senegal, Syria and Thailand). The results indicate that the redistribution method yields values of soil-water properties that have a large degree of uncertainty, and that this uncertainty is not necessarily related to the kind of soil being analysed. Regardless of the fundamental cause of this uncertainty (experimental and computational errors versus natural soil variability), the conclusion is that further developments of field technology depend upon stochastic rather than deterministic concepts
-
Directory of Open Access Journals (Sweden)
P. Chias
2013-07-01
Full Text Available Remote sensing techniques in Archaeology are increasingly essential components of the methodologies used in archaeological and architectural researches. They allow uncovering unique forgotten data which are unobtainable using traditional excavation techniques, mainly because their precise location is lost. These data are still important since they can help to prevent flood effects inside the ancient building cellars and basements, as it happened periodically in El Escorial. Wide ancient drainage galleries run more than one hundred feet downhill outside the building, ensuring that rainwater and springs were adequately drained. Nowadays their plans are lost, and the lack of documents related both to the ancient water supply and drainage systems become an impediment to solve the stains of damp on the stone masonry walls and vaults, and even other occasional flooding effects. In this case, nondestructive techniques were needed to find the ancient underground passages in order to preserve the integrity of the building and its current activities. At a first stage oblique aerial infrared images taken from a helium barrage balloon helped to find easily, quickly and cheaply the buried masonry structures. Secondly, radar pulses were particularly interesting to image the subsurface as they were valuable means of assessing the presence and amount of both soil water and buried structures. The combination of both techniques proved to be an accurate and low-cost way to find the ancient drainage systems. Finally, results were produced by means of open source software.
-
Li, Dong-wei; Li, Ming-si; Liu, Dong; Lyu, Mou-chao; Jia, Yan-hui
2015-08-01
Abstract: To explore the effects of soil wetting pattern on soil water-thermal environment and water consumption of cotton root under mulched drip irrigation, a field experiment with three drip intensities (1.69, 3.46 and 6.33 L · h(-1)), was carried out in Shihezi, Xinjiang Autonomous Region. The soil matric potential, soil temperature, cotton root distribution and water consumption were measured during the growing period of cotton. The results showed that the main factor influencing the soil temperature of cotton under plastic mulch was sunlight. There was no significant difference in the soil temperature and root water uptake under different treatments. The distribution of soil matrix suction in cotton root zone under plastic mulch was more homogeneous under ' wide and shallow' soil wetting pattern (W633). Under the 'wide and shallow' soil wetting pattern, the average difference of cotton root water consumption between inner row and outer row was 0.67 mm · d(-1), which was favorable to the cotton growing trimly at both inner and outer rows; for the 'narrow and deep' soil wetting pattern (W169), the same index was 0.88 mm · d(-1), which was unfavorable to cotton growing uniformly at both inner and outer rows. So, we should select the broad-shallow type soil wetting pattern in the design of drip irrigation under mulch.
-
Guo, Tian; Gitau, Margaret; Merwade, Venkatesh; Arnold, Jeffrey; Srinivasan, Raghavan; Hirschi, Michael; Engel, Bernard
2018-01-01
Subsurface tile drainage systems are widely used in agricultural watersheds in the Midwestern US and enable the Midwest area to become highly productive agricultural lands, but can also create environmental problems, for example nitrate-N contamination associated with drainage waters. The Soil and Water Assessment Tool (SWAT) has been used to model watersheds with tile drainage. SWAT2012 revisions 615 and 645 provide new tile drainage routines. However, few studies have used these revisions to study tile drainage impacts at both field and watershed scales. Moreover, SWAT2012 revision 645 improved the soil moisture based curve number calculation method, which has not been fully tested. This study used long-term (1991-2003) field site and river station data from the Little Vermilion River (LVR) watershed to evaluate performance of tile drainage routines in SWAT2009 revision 528 (the old routine) and SWAT2012 revisions 615 and 645 (the new routine). Both the old and new routines provided reasonable but unsatisfactory (NSE runoff. The calibrated monthly tile flow, surface flow, nitrate-N in tile and surface flow, sediment and annual corn and soybean yield results from SWAT with the old and new tile drainage routines were compared with observed values. Generally, the new routine provided acceptable simulated tile flow (NSE = 0.48-0.65) and nitrate in tile flow (NSE = 0.48-0.68) for field sites with random pattern tile and constant tile spacing, while the old routine simulated tile flow and nitrate in tile flow results for the field site with constant tile spacing were unacceptable (NSE = 0.00-0.32 and -0.29-0.06, respectively). The new modified curve number calculation method in revision 645 (NSE = 0.50-0.81) better simulated surface runoff than revision 615 (NSE = -0.11-0.49). The calibration provided reasonable parameter sets for the old and new routines in the LVR watershed, and the validation results showed that the new routine has the potential to accurately
-
Yousfi, Ammar; Mechergui, Mohammed
2016-04-01
The seepage face is an important feature of the drainage process when recharge occurs to a permeable region with lateral outlets. Examples of the formation of a seepage face above the downstream water level include agricultural land drained by ditches. Flow problem to these drains has been investigated extensively by many researchers (e.g. Rubin, 1968; Hornberger et al. 1969; Verma and Brutsaert, 1970; Gureghian and Youngs, 1975; Vauclin et al., 1975; Skaggs and Tang, 1976; Youngs, 1990; Gureghian, 1981; Dere, 2000; Rushton and Youngs, 2010; Youngs, 2012; Castro-Orgaz et al., 2012) and may be tackled either using variably saturated flow models, or the complete 2-D solution of Laplace equation, or using the Dupuit-Forchheimer approximation; the most widely accepted methods to obtain analytical solutions for unconfined drainage problems. However, the investigation reported by Clement et al. (1996) suggest that accounting for the seepage face alone, as in the fully saturated flow model, does not improve the discharge estimate because of disregarding flow the unsaturated zone flow contribution. This assumption can induce errors in the location of the water table surface and results in an underestimation of the seepage face and the net discharge (e.g. Skaggs and Tang, 1976; Vauclin et al., 1979; Clement et al., 1996). The importance of the flow in the unsaturated zone has been highlighted by many authors on the basis of laboratory experiments and/or numerical experimentations (e.g. Rubin, 1968; Verma and Brutsaert, 1970; Todsen, 1973; Vauclin et al., 1979; Ahmad et al., 1993; Anguela, 2004; Luthin and Day, 1955; Shamsai and Narasimhan, 1991; Wise et al., 1994; Clement et al., 1996; Boufadel et al., 1999; Romano et al., 1999; Kao et al., 2001; Kao, 2002). These studies demonstrate the failure of fully saturated flow models and suggested that the error made when using these models not only depends on soil properties but also on the infiltration rate as reported by Kao et
-
Jones, Sam P.; Ogée, Jérôme; Sauze, Joana; Wohl, Steven; Saavedra, Noelia; Fernández-Prado, Noelia; Maire, Juliette; Launois, Thomas; Bosc, Alexandre; Wingate, Lisa
2017-12-01
The contribution of photosynthesis and soil respiration to net land-atmosphere carbon dioxide (CO2) exchange can be estimated based on the differential influence of leaves and soils on budgets of the oxygen isotope composition (δ18O) of atmospheric CO2. To do so, the activity of carbonic anhydrases (CAs), a group of enzymes that catalyse the hydration of CO2 in soils and plants, needs to be understood. Measurements of soil CA activity typically involve the inversion of models describing the δ18O of CO2 fluxes to solve for the apparent, potentially catalysed, rate of CO2 hydration. This requires information about the δ18O of CO2 in isotopic equilibrium with soil water, typically obtained from destructive, depth-resolved sampling and extraction of soil water. In doing so, an assumption is made about the soil water pool that CO2 interacts with, which may bias estimates of CA activity if incorrect. Furthermore, this can represent a significant challenge in data collection given the potential for spatial and temporal variability in the δ18O of soil water and limited a priori information with respect to the appropriate sampling resolution and depth. We investigated whether we could circumvent this requirement by inferring the rate of CO2 hydration and the δ18O of soil water from the relationship between the δ18O of CO2 fluxes and the δ18O of CO2 at the soil surface measured at different ambient CO2 conditions. This approach was tested through laboratory incubations of air-dried soils that were re-wetted with three waters of different δ18O. Gas exchange measurements were made on these soils to estimate the rate of hydration and the δ18O of soil water, followed by soil water extraction to allow for comparison. Estimated rates of CO2 hydration were 6.8-14.6 times greater than the theoretical uncatalysed rate of hydration, indicating that CA were active in these soils. Importantly, these estimates were not significantly different among water treatments, suggesting
-
Cover crops impact on excess rainfall and soil erosion rates in orchards and potato fields, Israel
Egozi, Roey; Gil, Eshel
2015-04-01
Bare soil and high drainage densities are common characteristics of intensive agriculture land. The couplings of these characteristics lead to high runoff and eroded soil volumes leaving the field or the orchard via the local drainage system into the fluvial system. This process increase flood risk due to massive deposition of the coarse fraction of the eroded soil and therefore reduces channel capacity to discharge the increase volumes of concentrated runoff. As a result drainage basin authorities are forced to invest large amount of money in maintaining and enlarging the drainage network. However this approach is un-sustainable. On the other hand, implementing cover crops (CC) and modification to current agricultural practices over the contributing area of the watershed seems to have more benefits and provide sustainable solution. A multi-disciplinary approach applied in commercial potatoes fields and orchards that utilize the benefit of CC shows great success as means of soil and water conservation and weed disinfestation without reduction in the yield, its quality or its profitability. The results indicate that it is possible to grow potatoes and citrus trees under CC with no reduction in yield or nutrient uptake, with more than 95% reduction in soil loss and more than 60% in runoff volumes and peak discharges.
-
Geochemical signature and phytoremediation of urban soil: a case in Barcelona city
Rodríguez-Bocanegra, Javier; Roca, Núria; Febrero, Anna; Bort, Jordi
2016-04-01
The cleanup of contaminated places with heavy metals is necessary, but environmental remediation strategies are often expensive and energy consuming. Thus, it is important to develop low-cost and environmentally friendly strategies. Phytoremediation-based technologies could provide a long-lasting solution. The study area is located in Sants, a neighbourhood in Barcelona city (Catalonia, Spain). This place was an industrial area in the last century, which was occupied by a metal smelting industry. Nowadays, the neighbours want to cultivate vegetables in this location, but the history of this area suggests that the soil is polluted by elevated concentrations of heavy metals. The aim of this work was to determine heavy metal concentration in: a) soil, to know the degree of the soil pollution; b) roots and leaves of two plant species, Brassica juncea as an accumulator plant and Solanum lycopersicum as a crop plant, to know the capacity of each species to accumulate metals, and c) drainage water, to evaluate the heavy metal mobility. The main pollutants are Cu, Pb and Zn with topsoil total concentrations about 1355, 2230 and 6239 mg•kg-1, respectively. The established background upper limits in this area in mg•kg-1 were: Cu 145, Pb 91 and Zn 326. The same soil elements for available fractions, extracted with DTPA, were slightly elevated (9.6, 5.8 and 6.7 % of total concentration). The environmental pollution implies great extractability, suggesting the plants in these soils have facility with potentially toxic elements absorption. Instead, the concentrations in subsoil are lower than in topsoil. The concentrations of Cu, Pb and Zn in the plants' leaves are greater in B. juncea 170 ± 52.7, 137 ± 46.3 and 2365 ± 860.4 mg•kg-1, than in S. lycopersicum 102.5 ± 7.1, 22.5 ± 1.3 and 1002 ± 85.2 mg•kg-1 respectively. Furthermore, they are also greater in roots than in leaves. All of them are lower than the threshold to be considered like a hyperaccumulator species
-
Directory of Open Access Journals (Sweden)
Petr Karásek
2015-01-01
Full Text Available This study searched for associations between the extent of hydromelioration systems and the land use (in the past and at present, degree of nature conservation, and infiltration of water through soil profile in the Protected Landscape Area (PLA Železné hory. According to the available evidence, 34.6% of arable land and 32.1% of permanent grasslands in this area are drained by the drainage systems. Analysis of the original design documentations of drainage structures indicate, that the extent of drained areas can actually be even higher. The hydromelioration systems were built namely in the second half of the 20th century. The drainage also affected alluvial meadows, wetlands, and ecologically valuable stations. After establishment of PLA Železné hory in 1991, the protected area was divided into four zones according to their significance and protection regime. This study has revealed the presence of areas drained by systematic drainage systems (101 ha of grasslands even in the zones of highest landscape protection degree (1st and 2nd protection zones. The inadequately executed drainage systems should be eliminated and the character of the land should be brought closer to its natural conditions. On the model part of the PLA we also performed a study of historical changes in the landscape in three time horizons (1839, 1950, 2014 to show differences in land use before building of drainage, at the time of building, and at present.
-
Abreu,Adriana Trópia de; Faria,Efigênia Miranda de; Chaves,Carla Thamilis Fonseca; Leite,Adilson do Lago; Lena,Jorge Carvalho de
2014-01-01
Acid mine drainage is the result of the oxidation process of sulfide bearing rocks. This process occurs when the sulfide material is exposed to atmospheric conditions. Under these conditions, successive oxidation reactions yield sulfuric acid generating acidic waters. This problem becomes more serious when the surrounding rocks are not able to neutralize the acid. The low pH condition of the drained water accelerates the solubility process of solid materials (rocks, soils and sediments) and f...
-
Large zero-tension plate lysimeters for soil water and solute collection in undisturbed soils
Directory of Open Access Journals (Sweden)
A. Peters
2009-09-01
Full Text Available Water collection from undisturbed unsaturated soils to estimate in situ water and solute fluxes in the field is a challenge, in particular if soils are heterogeneous. Large sampling devices are required if preferential flow paths are present. We present a modular plate system that allows installation of large zero-tension lysimeter plates under undisturbed soils in the field. To investigate the influence of the lysimeter on the water flow field in the soil, a numerical 2-D simulation study was conducted for homogeneous soils with uni- and bimodal pore-size distributions and stochastic Miller-Miller heterogeneity. The collection efficiency was found to be highly dependent on the hydraulic functions, infiltration rate, and lysimeter size, and was furthermore affected by the degree of heterogeneity. In homogeneous soils with high saturated conductivities the devices perform poorly and even large lysimeters (width 250 cm can be bypassed by the soil water. Heterogeneities of soil hydraulic properties result into a network of flow channels that enhance the sampling efficiency of the lysimeter plates. Solute breakthrough into zero-tension lysimeter occurs slightly retarded as compared to the free soil, but concentrations in the collected water are similar to the mean flux concentration in the undisturbed soil. To validate the results from the numerical study, a dual tracer study with seven lysimeters of 1.25×1.25 m area was conducted in the field. Three lysimeters were installed underneath a 1.2 m filling of contaminated silty sand, the others deeper in the undisturbed soil. The lysimeters directly underneath the filled soil material collected water with a collection efficiency of 45%. The deeper lysimeters did not collect any water. The arrival of the tracers showed that almost all collected water came from preferential flow paths.
-
Energy Technology Data Exchange (ETDEWEB)
Mitsuno, T; Nagahori, K [Okayama Univ., Okayama (Japan). Faculty of Agriculture; Yamamoto, T [Ministry of Agriculture, Forestry and Fisheries, Tokyo (Japan)
1991-09-01
Polders have no basin of their own, and the supply of irrigation water in polders is always short and unstable. The irrigation water system is so structured that the conflicting objects of both the insurance of irrigation water and drainage of rainwater can be achieved. Quoting an example at the surrounding area of the Kojima Bay in the southern area of Okayaja Prefecture where inning (land reclamation by drainage) has been practiced for a long time, problems in drainage improvement required for better use of low-lying flat lands are discussed. There are complicate relations among the safety against flood, rainwater drainage capability, stock capacity, and critical leveling time, therefore, the basic operation which must be performed at first in making a drainage plan is to determine the basic framework of the plan taking those relations into consideration. In low-lying flat lands, safety of the total area against flood has been established basing on the stock capacity of the paddy fields, and it is important to secure paddy field areas to a certain extent. 8 refs., 7 figs., 1 tab.
-
Laclau, J P; Arnaud, M; Bouillet, J P; Ranger, J
2001-02-01
Spatial statistical analyses were performed to describe root distribution and changes in soil strength in a mature clonal plantation of Eucalyptus spp. in the Congo. The objective was to analyze spatial variability in root distribution. Relationships between root distribution, soil strength and the water and nutrient uptake by the stand were also investigated. We studied three, 2.35-m-wide, vertical soil profiles perpendicular to the planting row and at various distances from a representative tree. The soil profiles were divided into 25-cm2 grid cells and the number of roots in each of three diameter classes counted in each grid cell. Two profiles were 2-m deep and the third profile was 5-m deep. There was both vertical and horizontal anisotropy in the distribution of fine roots in the three profiles, with root density decreasing sharply with depth and increasing with distance from the stump. Roots were present in areas with high soil strength values (> 6,000 kPa). There was a close relationship between soil water content and soil strength in this sandy soil. Soil strength increased during the dry season mainly because of water uptake by fine roots. There were large areas with low root density, even in the topsoil. Below a depth of 3 m, fine roots were spatially concentrated and most of the soil volume was not explored by roots. This suggests the presence of drainage channels, resulting from the severe hydrophobicity of the upper soil.
-
Characteristics of water infiltration in layered water repellent soils
Hydrophobic soil can influence soil water infiltration, but information regarding the impacts of different levels of hydrophobicity within a layered soil profile is limited. An infiltration study was conducted to determine the effects of different levels of hydrophobicity and the position of the hyd...
-
Bigham, Jerry M.; Cravotta, Charles A.
2016-01-01
Acid mine drainage (AMD) consists of metal-laden solutions produced by the oxidative dissolution of iron sulfide minerals exposed to air, moisture, and acidophilic microbes during the mining of coal and metal deposits. The pH of AMD is usually in the range of 2–6, but mine-impacted waters at circumneutral pH (5–8) are also common. Mine drainage usually contains elevated concentrations of sulfate, iron, aluminum, and other potentially toxic metals leached from rock that hydrolyze and coprecipitate to form rust-colored encrustations or sediments. When AMD is discharged into surface waters or groundwaters, degradation of water quality, injury to aquatic life, and corrosion or encrustation of engineered structures can occur for substantial distances. Prevention and remediation strategies should consider the biogeochemical complexity of the system, the longevity of AMD pollution, the predictive power of geochemical modeling, and the full range of available field technologies for problem mitigation.
-
Energy Technology Data Exchange (ETDEWEB)
Robalinho, Aviani Maria Bezerra
2000-10-01
The determination of the hydraulic properties of an alluvial soil in Cajueiro reservoir has been carried out in two experimental plots of 3.5 m x 3.5 m, installed in the opposite banks of the brook in which is located the dam, (Tuparetama Country, Pernambuco). For the determination of the hydraulic conductivity as a function of the soil water volumetric content K({theta}), the internal driainage method proposed by Hillel et al. (1972) has been applied. The soil-water retention curves h ({theta}) have been determined through the experimental data of volumetric water content and pressure obtained in field experiments. The h ({theta}) and K ({theta}) curves have been fitted to van Genuchten's closed - form equations (1980), using the Burdine's model, and Brooks and Corey's model, respectively. The volumetric water content, matric potential, and total water content estimates have been fitted to two analytical functions: one being composed by the addition of three exponentials terms the other composed and by representation the reverse of the power functions. The latter has been preferred due to its smoother representation between the fast and the slow its drainage phases. Considering the hydraulic behavior, three different layers have been identified in the soil profiles of the two experimental parcels A2 and B4 in the alluvial soil Cajueiro reservoir. The second layer of the soil profile in parcel A2 turned out the more pemeable than the other two layers. As to the soil profile in parcel B4, the first layer turned out more conductive than the other layers. However, the biggest volumetric water content variations were due to the differences found in the texture and structure of the soil profiles under study. The hydrodynamic characterization of the two soil profiles, A2 and B4, brings significant elements for the simulation of scenarios related to the soil of water transport processes. It is of particular importance the study of scenarios related to the
-
Bhadha, J. H.; Lang, T.; Daroub, S.
2012-12-01
The buildup of highly labile, organic, phosphorus (P)-enriched sediments in farms canals within the Everglades Agricultural Area (EAA) has been associated with the production of floating aquatic vegetation. During drainage events, these sediments are susceptible to transport and contribute to the overall P load. In order to evaluate the total P load exiting the farm canals, a settling tank experiment was conducted to capture the sediments during drainage events from eight farms. Drainage water was channelized through two 200L polypropylene collection tanks which allowed sediments to settle at the bottom based on its particle size. Water was carefully siphoned out of the tanks and the sediments collected for analyses. A five step P-fractionation process was used to distinguish organic (o) and inorganic (i) forms of P: KCl extractable P, NaOH extractable P, HCl extractable P, and residual P. The KCl-Pi fraction represents the labile Pi that is water soluble and exchangeable (loosely adsorbed); NaOH extractable P represents Fe- and Al- bound inorganic P (NaOH-Pi) and organic P associated with humic and fulvic acids (NaOH-Po). The HCl-Pi fraction includes Ca- and Mg- bound P, while Residue-P represents recalcitrant organic P compounds and P bound to minerals. The sediments were also used to conduct a P-flux study under both aerobic and anaerobic conditions. Our goal is to provide growers with vital information and insight into P loading that will help them in their efforts to reduce off-farm P loads in the EAA.
-
Spatial variations in water composition at a northern Canadian lake impacted by mine drainage
International Nuclear Information System (INIS)
Moncur, M.C.; Ptacek, C.J.; Blowes, D.W.; Jambor, J.L.
2006-01-01
Release of acid drainage from mine-waste disposal areas is a problem of international scale. Contaminated surface water, derived from mine wastes, originates both as direct surface runoff and, indirectly, as subsurface groundwater flow. At Camp Lake, a small Canadian Shield lake that is in northern Manitoba and is ice-covered 6 months of the year, direct and indirect release of drainage from an adjacent sulfide-rich tailings impoundment has severely affected the quality of the lake water. Concentrations of the products from sulfide oxidation are extremely high in the pore waters of the tailings impoundment. Groundwater and surface water derived from the impoundment discharge into a semi-isolated shallow bay in Camp Lake. The incorporation of this aqueous effluent has altered the composition of the lake water, which in turn has modified the physical limnology of the lake. Geochemical profiles of the water column indicate that, despite its shallow depth (6 m), the bay is stratified throughout the year. The greatest accumulation of dissolved metals and SO 4 is in the lower portion of the water column, with concentrations up to 8500 mg L -1 Fe, 20,000 mg L -1 SO 4 , 30 mg L -1 Zn, 100 mg L -1 Al, and elevated concentrations of Cu, Cd, Pb and Ni. Meromictic conditions and very high solute concentrations are limited to the bay. Outside the bay, solute concentrations are lower and some stratification of the water column exists. Identification of locations and composition of groundwater discharge relative to lake bathymetry is a fundamental aspect of understanding chemical evolution and physical stability of mine-impacted lakes
-
Salvucci, Guido D.
2000-01-01
The overall goal of this research is to examine the feasibility of applying a newly developed diagnostic model of soil water evaporation to large land areas using remotely sensed input parameters. The model estimates the rate of soil evaporation during periods when it is limited by the net transport resulting from competing effects of capillary rise and drainage. The critical soil hydraulic properties are implicitly estimated via the intensity and duration of the first stage (energy limited) evaporation, removing a major obstacle in the remote estimation of evaporation over large areas. This duration, or 'time to drying' (t(sub d)) is revealed through three signatures detectable in time series of remote sensing variables. The first is a break in soil albedo that occurs as a small vapor transmission zone develops near the surface. The second is a break in either surface to air temperature differences or in the diurnal surface temperature range, both of which indicate increased sensible heat flux (and/or storage) required to balance the decrease in latent heat flux. The third is a break in the temporal pattern of near surface soil moisture. Soil moisture tends to decrease rapidly during stage I drying (as water is removed from storage), and then become more or less constant during soil limited, or 'stage II' drying (as water is merely transmitted from deeper soil storage). The research tasks address: (1) improvements in model structure, including extensions to transpiration and aggregation over spatially variable soil and topographic landscape attributes; and (2) applications of the model using remotely sensed input parameters.
-
Influence of salinity and water content on soil microorganisms
Directory of Open Access Journals (Sweden)
Nan Yan
2015-12-01
Full Text Available Salinization is one of the most serious land degradation problems facing world. Salinity results in poor plant growth and low soil microbial activity due to osmotic stress and toxic ions. Soil microorganisms play a pivotal role in soils through mineralization of organic matter into plant available nutrients. Therefore it is important to maintain high microbial activity in soils. Salinity tolerant soil microbes counteract osmotic stress by synthesizing osmolytes which allows them to maintain their cell turgor and metabolism. Osmotic potential is a function of the salt concentration in the soil solution and therefore affected by both salinity (measured as electrical conductivity at a certain water content and soil water content. Soil salinity and water content vary in time and space. Understanding the effect of changes in salinity and water content on soil microorganisms is important for crop production, sustainable land use and rehabilitation of saline soils. In this review, the effects of soil salinity and water content on microbes are discussed to guide future research into management of saline soils.
-
Soil Water and Temperature System (SWATS) Instrument Handbook
Energy Technology Data Exchange (ETDEWEB)
Cook, David R. [Argonne National Lab. (ANL), Argonne, IL (United States)
2016-04-01
The soil water and temperature system (SWATS) provides vertical profiles of soil temperature, soil-water potential, and soil moisture as a function of depth below the ground surface at hourly intervals. The temperature profiles are measured directly by in situ sensors at the Central Facility and many of the extended facilities of the U.S. Department of Energy (DOE)’s Atmospheric Radiation Measurement (ARM) Climate Research Facility Southern Great Plains (SGP) site. The soil-water potential and soil moisture profiles are derived from measurements of soil temperature rise in response to small inputs of heat. Atmospheric scientists use the data in climate models to determine boundary conditions and to estimate the surface energy flux. The data are also useful to hydrologists, soil scientists, and agricultural scientists for determining the state of the soil.
-
Predicting and mapping soil available water capacity in Korea.
Hong, Suk Young; Minasny, Budiman; Han, Kyung Hwa; Kim, Yihyun; Lee, Kyungdo
2013-01-01
The knowledge on the spatial distribution of soil available water capacity at a regional or national extent is essential, as soil water capacity is a component of the water and energy balances in the terrestrial ecosystem. It controls the evapotranspiration rate, and has a major impact on climate. This paper demonstrates a protocol for mapping soil available water capacity in South Korea at a fine scale using data available from surveys. The procedures combined digital soil mapping technology with the available soil map of 1:25,000. We used the modal profile data from the Taxonomical Classification of Korean Soils. The data consist of profile description along with physical and chemical analysis for the modal profiles of the 380 soil series. However not all soil samples have measured bulk density and water content at -10 and -1500 kPa. Thus they need to be predicted using pedotransfer functions. Furthermore, water content at -10 kPa was measured using ground samples. Thus a correction factor is derived to take into account the effect of bulk density. Results showed that Andisols has the highest mean water storage capacity, followed by Entisols and Inceptisols which have loamy texture. The lowest water retention is Entisols which are dominated by sandy materials. Profile available water capacity to a depth of 1 m was calculated and mapped for Korea. The western part of the country shows higher available water capacity than the eastern part which is mountainous and has shallower soils. The highest water storage capacity soils are the Ultisols and Alfisols (mean of 206 and 205 mm, respectively). Validation of the maps showed promising results. The map produced can be used as an indication of soil physical quality of Korean soils.
-
Predicting and mapping soil available water capacity in Korea
Directory of Open Access Journals (Sweden)
Suk Young Hong
2013-04-01
Full Text Available The knowledge on the spatial distribution of soil available water capacity at a regional or national extent is essential, as soil water capacity is a component of the water and energy balances in the terrestrial ecosystem. It controls the evapotranspiration rate, and has a major impact on climate. This paper demonstrates a protocol for mapping soil available water capacity in South Korea at a fine scale using data available from surveys. The procedures combined digital soil mapping technology with the available soil map of 1:25,000. We used the modal profile data from the Taxonomical Classification of Korean Soils. The data consist of profile description along with physical and chemical analysis for the modal profiles of the 380 soil series. However not all soil samples have measured bulk density and water content at −10 and −1500 kPa. Thus they need to be predicted using pedotransfer functions. Furthermore, water content at −10 kPa was measured using ground samples. Thus a correction factor is derived to take into account the effect of bulk density. Results showed that Andisols has the highest mean water storage capacity, followed by Entisols and Inceptisols which have loamy texture. The lowest water retention is Entisols which are dominated by sandy materials. Profile available water capacity to a depth of 1 m was calculated and mapped for Korea. The western part of the country shows higher available water capacity than the eastern part which is mountainous and has shallower soils. The highest water storage capacity soils are the Ultisols and Alfisols (mean of 206 and 205 mm, respectively. Validation of the maps showed promising results. The map produced can be used as an indication of soil physical quality of Korean soils.
-
Tribouillois, Hélène; Constantin, Julie; Justes, Eric
2018-02-14
Cover crops provide ecosystem services such as storing atmospheric carbon in soils after incorporation of their residues. Cover crops also influence soil water balance, which can be an issue in temperate climates with dry summers as for example in southern France and Europe. As a consequence, it is necessary to understand cover crops' long-term influence on greenhouse gases (GHG) and water balances to assess their potential to mitigate climate change in arable cropping systems. We used the previously calibrated and validated soil-crop model STICS to simulate scenarios of cover crop introduction to assess their influence on rainfed and irrigated cropping systems and crop rotations distributed among five contrasted sites in southern France from 2007 to 2052. Our results showed that cover crops can improve mean direct GHG balance by 315 kg CO 2 e ha -1 year -1 in the long term compared to that of bare soil. This was due mainly to an increase in carbon storage in the soil despite a slight increase in N 2 O emissions which can be compensated by adapting fertilization. Cover crops also influence the water balance by reducing mean annual drainage by 20 mm/year but increasing mean annual evapotranspiration by 20 mm/year compared to those of bare soil. Using cover crops to improve the GHG balance may help to mitigate climate change by decreasing CO 2 e emitted in cropping systems which can represent a decrease from 4.5% to 9% of annual GHG emissions of the French agriculture and forestry sector. However, if not well managed, they also could create water management issues in watersheds with shallow groundwater. Relationships between cover crop biomass and its influence on several variables such as drainage, carbon sequestration, and GHG emissions could be used to extend our results to other conditions to assess the cover crops' influence in a wider range of areas. © 2018 John Wiley & Sons Ltd.
-
Response of three soil water sensors to variable solution electrical conductivity in different soils
Commercial dielectric soil water sensors may improve management of irrigated agriculture by providing continuous field soil water information. Use of these sensors is partly limited by sensor sensitivity to variations in soil salinity and texture, which force expensive, time consuming, soil specific...
-
Ruppert, David E; Needelman, Brian A; Kleinman, Peter J A; Rabenhorst, Martin C; Momen, Bahram; Wester, David B
2017-05-01
Agricultural drainage ditches function as first-order streams and affect nutrient management. Soil mesocosms from a ditch featuring a vertical (increasing upward) gradient in iron (Fe) and phosphorus (P) were subjected to hydraulic and soil treatments. These manipulations mimicked aspects of dredging and controlled drainage and inspected the soil release and retention of P. Treatments did not remove P from simulated groundwater. Throughput water either gained in P (lack of dredging, especially under Fe-reducing conditions) or had P concentrations indistinguishable from input water (dredging). Undredged mesocosms, when Fe-reducing, released Fe and P simultaneously. Simultaneous release of P and Fe from our Fe-reducing mesocosms indicates a mechanism whereby P capture occurs by Fe precipitation upon emergence to aerated surficial waters. Upwelling and surficial phases of ditch hydrology and the lowering of the ditch surface on dredging complicate interpretation of traditional means of describing ditch P retention and release. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.
-
Vanclooster, Marnik
2010-05-01
The current societal demand for sustainable soil and water management is very large. The drivers of global and climate change exert many pressures on the soil and water ecosystems, endangering appropriate ecosystem functioning. The unsaturated soil transport processes play a key role in soil-water system functioning as it controls the fluxes of water and nutrients from the soil to plants (the pedo-biosphere link), the infiltration flux of precipitated water to groundwater and the evaporative flux, and hence the feed back from the soil to the climate system. Yet, unsaturated soil transport processes are difficult to quantify since they are affected by huge variability of the governing properties at different space-time scales and the intrinsic non-linearity of the transport processes. The incompatibility of the scales between the scale at which processes reasonably can be characterized, the scale at which the theoretical process correctly can be described and the scale at which the soil and water system need to be managed, calls for further development of scaling procedures in unsaturated zone science. It also calls for a better integration of theoretical and modelling approaches to elucidate transport processes at the appropriate scales, compatible with the sustainable soil and water management objective. Moditoring science, i.e the interdisciplinary research domain where modelling and monitoring science are linked, is currently evolving significantly in the unsaturated zone hydrology area. In this presentation, a review of current moditoring strategies/techniques will be given and illustrated for solving large scale soil and water management problems. This will also allow identifying research needs in the interdisciplinary domain of modelling and monitoring and to improve the integration of unsaturated zone science in solving soil and water management issues. A focus will be given on examples of large scale soil and water management problems in Europe.
-
Modelling mid-span water table depth and drainage discharge ...
African Journals Online (AJOL)
2015-04-03
Apr 3, 2015 ... were monitored in 1.7 m deep piezometers installed mid-way between two drains by using an electronic .... logical components in soils with shallow water tables. ..... dency of neither under-estimating nor over-estimating DDs,.
-
Effect of soil warming and rainfall patterns on soil N cycling in northern Europe
DEFF Research Database (Denmark)
Patil, Raveendra Hanumantagoud; Lægdsmand, Mette; Olesen, Jørgen Eivind
2010-01-01
. These changes may affect soil moisture regimes, soil water drainage, soil nitrogen (N) availability and N leaching to aquatic environment and N2O emissions to atmosphere. Thus it is important to study the effects of increased soil temperature and varying rainfall patterns on soil N cycling in arable land from...... temperate climates, which is a major source of N pollution. An open-field lysimeter study was carried out during 2008-2009 in Denmark on loamy sand soil (Typic Hapludult) with three factors: number of rainy days, rainfall amount and soil warming. Number of rainy days included the mean monthly rainy days...... by 5 °C at 0.1 m depth as ‘heated' and non-heated as ‘control' treatments. Automated mobile rain-out shelter and irrigation system, and insulated buried heating cables were used to impose the treatments. Soil warming, compared with unheated control, advanced winter wheat crop development, and increased...
-
DEFF Research Database (Denmark)
Bouyou, P.A. Léon; Weisser, Johan Juhl; Strobel, Bjarne W.
2014-01-01
% (relative standard deviation 15 %), while at 10 ng/L, it showed a lower recovery of 32 % (relative standard deviation 47 %). The final SPE LC-MS/MS method had a limit of detection (LOD)Method and a limit of quantification (LOQ)Method of 7.5 and 23 ng/L agricultural drainage water, respectively....... Determination of SDZ, spiked at a realistic concentration of 50 μg/L, in artificial drainage water (ADW) containing common and high levels of phosphate (0.05, 0.5, and 5 mg/L) gave recoveries between 70 and 92 % (relative standard deviation 7.4–12.9 %). Analysis of the same realistic concentration of SDZ in ADW...... obtained ranged from 104 to 109 % (relative standard deviation 2.8–5.2 %). The new methods enable determination of the veterinary antibiotic compound SDZ in agricultural drainage water from field experiments and monitoring schemes for phosphate- and dissolved organic carbon (DOC)-rich water samples...
-
Energy Technology Data Exchange (ETDEWEB)
Silva, Camila Goncalves Bof
2010-07-01
Phosphogypsum is a waste generated in phosphoric acid production by the 'wet process'. The immense amount of phosphogypsum yearly produced (around 150 million tons) is receiving attention from environmental protection agencies all over the word, given its potential of contamination. In Brazil, this material has been used for many decades, especially for agricultural application on cropland. Although the phosphogypsum is mainly composed of dehydrated calcium sulfate, it can have high levels of impurities, such as metals (Cd, Cr, Cu, Pb), non-metals (As and Se) and radioactive elements from natural series of {sup 232}Th and {sup 238}U. Therefore, its continuous application as an agricultural agent can result not just in soil contamination, but also contamination of the surface and groundwater due to the runoff and infiltration process. The concern associated with the contamination of aquatic environments increases; when water is used for human consumption, requiring progressive adoption of more restrictive limits. However, some of the conventional analytical techniques used to determine the maximum limit of contaminants in water have detection limits above the maximum limits established by the environmental legislation. This work was aimed to evaluate the mobility of metals and non-metals in soils and, consequently, the contamination of drainage water through greenhouse-scale leaching and transport of toxic elements from soils fertilized with phosphogypsum. Hence, methods were studied and implemented for determination of metals (Cd, Cr, Cu and Pb) using Furnace Graphite Atomic Absorption Spectrometry (GF AAS), as well as for non-metals (As and Se) using Inductively Coupled Plasma Mass Spectrometry (lCP-MS). Effects of different chemical modifiers on the determination of Cd, Cr, Cu and Pb concentration by GF AAS were also investigated. In general, it was observed that the metal and non-metal concentration were below than the actual detection limit of the
-
Using a simple model for water and nitrogen transport in soil in the practical works of Horticulture
Directory of Open Access Journals (Sweden)
A. Lidón
2017-08-01
Full Text Available Simulation models for the transport of water and nitrogen in the soil are useful tools for evaluating the consequences of different crop management practices without waiting until the end of the crop cycle. Particularly, simple compartmental models for the transport of water and nitrogen are based on the solution of mass balance equations for the water and a system of ordinary differential equations for the nitrogen cycle. In this work, these models are used to evaluate different possible scenarios of irrigation and nitrogen fertilization in a cauliflower crop, as a practical work for the students of Horticulture course. The results show that different irrigation and fertilization strategies lead to different results for the nitrate leaching, water drainage and nitrogen uptake.
-
Heavy Metal Displacement in Chelate-Assisted Phytoremediation of Biosolids Soil
Kirkham, M. B.; Liphadzi, M. S.
2005-05-01
Heavy metals in biosolids (sewage sludge) applied to land contaminate the soil. Phytoremediation, the use of plants to clean up toxic heavy metals, might remove them. Chelating agents are added to soil to solubilize the metals for enhanced phytoextraction. Yet no studies follow the displacement and leaching of heavy metals in soil with biosolids following solubilization with chelates. The objective of this work was to determine the mobility of heavy metals, as affected by a chelate, in soil (Haynie very fine sandy loam) from a 25-year old sludge farm. Soil columns (105 cm long; 39 cm in diameter) either had a plant (hybrid poplar; Populus deltoides Marsh. x P. nigra L.) or no plant. When the poplars were 144 days old, the tetrasodium salt of the chelating agent EDTA (ethylenediamine-tetraacetic acid) was irrigated onto the soil at a rate of 1 g per kg of soil. Drainage water, soil, and plants were analyzed for three toxic heavy metals (Cd, Ni, Pb) and four essential heavy metals (Cu, Fe, Mn, Zn). Without EDTA, concentrations of the seven heavy metals in the leachate from columns with or without plants were low or below detection limits. With or without plants, the EDTA mobilized all heavy metals and increased their concentration in drainage water. Without plants, the concentrations of Cd, Cu, Fe, Pb, and Zn in the leachate from columns with EDTA were above drinking-water standards. (There is no drinking-water standard for Ni.) The presence of poplar plants in the soil reduced the concentrations of Cu, Fe, and Zn in the leachate so it fell within drinking-water standards. Concentrations of Cd and Pb in the leachate remained above drinking-water standards with or without plants. At harvest (124 days after the EDTA application), total concentration of each heavy metal in the soil at different depths in the columns with EDTA was similar to that in the columns without EDTA. The chelate did not affect the concentration of heavy metals in the roots, stems, or leaves
-
Directory of Open Access Journals (Sweden)
Daniel F. de Carvalho
2015-11-01
Full Text Available ABSTRACTThis study evaluated soil and water losses, soil water infiltration and infiltration rate models in soil tillage systems and corn (Zea mays, L. development stages under simulated rainfall. The treatments were: cultivation along contour lines, cultivation down the slope and exposed soil. Soil losses and infiltration in each treatment were quantified for rains applied using a portable simulator, at 0, 30, 60 and 75 days after planting. Infiltration rates were estimated using the models of Kostiakov-Lewis, Horton and Philip. Based on the obtained results, the combination of effects between soil tillage system and corn development stages reduces soil and water losses. The contour tillage system promoted improvements in soil physical properties, favoring the reduction of erosion in 59.7% (water loss and 86.6% (soil loss at 75 days after planting, and the increase in the stable infiltration rate in 223.3%, compared with the exposed soil. Associated to soil cover, contour cultivation reduces soil and water losses, and the former is more influenced by management. Horton model is the most adequate to represent soil water infiltration rate under the evaluated conditions.
-
Elmi, Abdirashid A; Astatkie, Tess; Madramootoo, Chandra; Gordon, Robert; Burton, David
2005-01-01
The denitrification process and nitrous oxide (N2O) production in the soil profile are poorly documented because most research into denitrification has concentrated on the upper soil layer (0-0.15 m). This study, undertaken during the 1999 and 2000 growing seasons, was designed to examine the effects of water table management (WTM), nitrogen (N) application rate, and depth (0.15, 0.30, and 0.45 m) on soil denitrification end-products (N2O and N2) from a corn (Zea mays L.) field. Water table management treatments were free drainage (FD) with open drains and subirrigation (SI) with a target water table depth of 0.6 m. Fertility treatments (ammonium nitrate) were 120 kg N ha(-1) (N120) and 200 kg N ha(-1) (N200). During both growing seasons greater denitrification rates were measured in SI than in FD, particularly in the surface soil (0-0.15 m) and at the intermediate (0.15-0.30 m) soil depths under N200 treatment. Greater denitrification rates under the SI treatment, however, were not accompanied with greater N2O production. The decrease in N2O production under SI was probably caused by a more complete reduction of N2O to N2, which resulted in lower N2O to (N2O + N2) ratios. Denitrification rate, N2O production and N2O to (N2O + N2) ratios were only minimally affected by N treatments, irrespective of sampling date and soil depth. Overall, half of the denitrification occurred at the 0.15- to 0.30- and 0.30- to 0.45-m soil layers, and under SI, regardless of fertility treatment level. Consequently, sampling of the 0- to 0.15-m soil layer alone may not give an accurate estimation of denitrification losses under SI practice.
-
Flow of gasoline-in-water microemulsion through water-saturated soil columns
International Nuclear Information System (INIS)
Ouyang, Y.; Mansell, R.S.; Rhue, R.D.
1995-01-01
Much consideration has been given to the use of surfactants to clean up nonaqueous phase liquids (NAPLs) from contaminated soil and ground water. Although this emulsification technique has shown significant potential for application in environmental remediation practices, a major obstacle leading to low washing efficiency is the potential formation of macroemulsion with unfavorable flow characteristics in porous media. This study investigated influences of the flow of leaded-gasoline-in-water (LG/W) microemulsion upon the transport of gasoline and lead (Pb) species in water-saturated soil columns. Two experiments were performed: (1) the immiscible displacement of leaded gasoline and (2) the miscible displacement of LG/W microemulsion through soil columns, followed by sequentially flushing with NaCl solution and a water/surfactant/cosurfactant (W/S/CoS) mixture. Comparison of breakthrough curves (BTC) for gasoline between the two experiments shows that about 90% of gasoline and total Pb were removed from the soil columns by NaCl solution in the LG/W microemulsion experiment as compared to 40% removal of gasoline and 10% removal of total Pb at the same process in the leaded gasoline experiment. Results indicate that gasoline and Pb species moved much more effectively through soil during miscible flow of LG/W microemulsion than during immiscible flow of leaded gasoline. In contrast to the adverse effects of macroemulsion on the transport of NAPLs, microemulsion was found to enhance the transport of gasoline through water-saturated soil. Mass balance analysis shows that the W/S/CoS mixture had a high capacity for removing residual gasoline and Pb species from contaminated soil. Comparison of water-pressure differences across the soil columns for the two experiments indicates that pore clogging by gasoline droplets was greatly minimized in the LG/W microemulsion experiment
-
Butler, D.L.; Krueger, R.P.; Osmundson, B.C.; Thompson, A.L.; Formea, J.J.; Wickman, D.W.
1993-01-01
During 1988-89, water, bottom sediment, biota, soil, and plants were sampled for a reconnaissance investigation of the Pine River Project area in southwestern Colorado. Irrigation drainage does not seem to be a major source of dissolved solids in streams. Concentrations of manganese, mercury, and selenium exceeded drinking-water regulations in some streams. The maximum selenium concentration in a stream sample was 94 microg/L in Rock Creek. Irrigation drainage and natural groundwater are sources of some trace elements to streams. Water from a well in a nonirrigated area had 4,800 microg/L of selenium. Selenium concentrations in soil on the Oxford Tract were greater in areas previously or presently irrigated than in areas never irrigated. Some forage plants on the Oxford Tract had large selenium concentrations, including 180 mg/km in alfalfa. Most fish samples had selenium concentrations greater than the National Contaminant Biomonitoring Program 85th percentile. Selenium concentrations in aquatic plants, aquatic inverte- brates, and small mammals may be of concern to fish and wildlife because of possible food-chain bioconcentration. Selenium concentrations in bird samples indicate selenium contamination of biota on the Oxford Tract. Mallard breasts had selenium concentrations exceeding a guideline for human consumption. The maximum selenium concentration in biota was 50 microg/g dry weight in a bird liver from the Oxford Tract. In some fish samples, arsenic, cadmium, copper, and zinc exceeded background concentrations, but concentrations were not toxic. Mercury concentrations in 16 fish samples exceeded the background concentration. Ten mercury concentrations in fish exceeded a guideline for mercury in food for consumption by pregnant women.
-
Directory of Open Access Journals (Sweden)
mehdi amini
2013-12-01
Full Text Available In copper heap leaching structures, the ore is leached by an acidic solution. After dissolving the ore mineral, the heap is drained off in the acidic solution using a drainage system (consisting of a network of perforated polyethylene pipes and gravelly drainage layers and is, then, transferred to the leaching plant for copper extraction where the copper is extracted and the remaining solution is dripped over the ore heap for re-leaching. In this process, the reaction between the acidic solution and copper oxide ore is exothermal and the pregnant leach solution (PLS, which is drained off the leaching heap, has a higher temperature than the dripped acidic solution. The PLS temperature variations cause some changes in the viscosity and density which affect the gravelly drainage layer's permeability. In this research, a special permeability measuring system was devised for determining the effects of the PLS temperature variations on the permeability coefficient of the gravelly drainage layer of heap leaching structures. The system, consisting of a thermal acid resistant element and a thermocouple, controls the PLS temperature, which helps measure the permeability coefficient of the gravelly drainage layer. The PLS and gravelly drainage layer of Sarcheshmeh copper mine heap leaching structure No. 1 were used in this study. The permeability coefficient of the gravelly soil was measured against the PLS and pure water at temperatures varying between 3°C to 60°C. Also, the viscosity and density of the PLS and pure water were measured at these temperatures and, using existing theoretical relations, the permeability coefficient of the gravel was computed. A comparison between the experimental and theoretical results revealed a good conformity between the two sets of results. Finally, a case (Taft heap leaching structure, Yazd, Iran was studied and its gravelly drainage layer was designed based on the results of the present research.
-
Drainage from coal mines: Chemistry and environmental problems
International Nuclear Information System (INIS)
Wildeman, T.
1991-01-01
Much of the research on coal-mine drainage chemistry was conducted a decade ago, and now increased environmental awareness has brought about renewed interest in the findings. Consideration of the trace minerals and elements in coal points to the possible generation of acidic waters upon weathering, especially when pyrite is present. When pyrite weathers, it produces H + and Fe 3+ which catalyze the incongruent weathering of other carbonates and sulfides. In this weathering mechanism, catalysis by bacteria is important. Of the environmental problems in coal mine drainage, the mineral acidity of the water is the most serious. This is caused not only by the H + , but also by Mn 4+ , Fe 3+ , and Al 3+ that are found or generated within the drainage. Case studies in Kentucky, Pennsylvania, Illinois, and Colorado show that the abundance and form of pyrite in the deposit and in the overburden determines the level of acidity and the concentration of heavy metal pollutants in the drainage. Recent trends in environmental enforcement that emphasize integrated stream water standards and biotoxicity assays point to the possibility that the concentrations of heavy metals in coal mine drainages may cause environmental concern
-
International Nuclear Information System (INIS)
Aikman, M.; Mirotchnik, K.; Kantzas, A.
1997-01-01
A potential remediation method for hydrocarbon contaminated soils was discussed. The new method was based on the use of proven and economic petroleum reservoir engineering methods for soil remediation. The methods that were applied included water and gas displacement methods together with horizontal boreholes as the flow inlet and outlets. This system could be used in the case of spills that seep beneath a plant or other immovable infrastructure which requires in-situ treatment schemes to decontaminate the soil. A study was conducted to characterize native soils and water samples from industrial plants in central Alberta and Sarnia, Ontario and to determine the variables that impact upon the flow conditions of synthetic test materials. The methods used to characterize the soils included X-Ray computed tomographic analysis, grain size and density measurements, and X-Ray diffraction. Clay content, initial water saturation, and water and gas flow rate were the variables that impacted on the flow conditions
-
DEFF Research Database (Denmark)
Callesen, Ingeborg; Vesterdal, Lars; Stupak, Inge
drainage regime of soils that were frequently water saturated in previous centuries. It was also hypothesized that carbon gains in soils with a low or intermediate carbon stock, typical of well-drained soils, reflected the favorable, high precipitation conditions during the monitoring period, allowing...
-
Rezanezhad, F.; Couture, R.-M.; Kovac, R.; O'Connell, D.; Van Cappellen, P.
2014-02-01
Water table fluctuations significantly affect the biological and geochemical functioning of soils. Here, we introduce an automated soil column system in which the water table regime is imposed using a computer-controlled, multi-channel pump connected to a hydrostatic equilibrium reservoir and a water storage reservoir. The potential of this new system is illustrated by comparing results from two columns filled with 45 cm of the same homogenized riparian soil. In one soil column the water table remained constant at -20 cm below the soil surface, while in the other the water table oscillated between the soil surface and the bottom of the column, at a rate of 4.8 cm d-1. The experiment ran for 75 days at room temperature (25 ± 2 °C). Micro-sensors installed at -10 and -30 cm below the soil surface in the stable water table column recorded constant redox potentials on the order of 600 and -200 mV, respectively. In the fluctuating water table column, redox potentials at the same depths oscillated between oxidizing (∼700 mV) and reducing (∼-100 mV) conditions. Pore waters collected periodically and solid-phase analyses on core material obtained at the end of the experiment highlighted striking geochemical differences between the two columns, especially in the time series and depth distributions of Fe, Mn, K, P and S. Soil CO2 emissions derived from headspace gas analysis exhibited periodic variations in the fluctuating water table column, with peak values during water table drawdown. Transient redox conditions caused by the water table fluctuations enhanced microbial oxidation of soil organic matter, resulting in a pronounced depletion of particulate organic carbon in the midsection of the fluctuating water table column. Denaturing Gradient Gel Electrophoresis (DGGE) revealed the onset of differentiation of the bacterial communities in the upper (oxidizing) and lower (reducing) soil sections, although no systematic differences in microbial community structure
-
Directory of Open Access Journals (Sweden)
Guangya Jin
2017-01-01
Full Text Available Aqueous crude oil often contains large amounts of produced water and heavy sediment, which seriously threats the safety of crude oil storage and transportation. Therefore, the proper design of crude oil tank drainage device is prerequisite for efficient purification of aqueous crude oil. In this work, the composition and physicochemical properties of crude oil samples were tested under the actual conditions encountered. Based on these data, an appropriate crude oil tank drainage device was developed using the principle of floating ball and multiphase flow. In addition, the flow field characteristics in the device were simulated and the contours and streamtraces of velocity magnitude at different nine moments were obtained. Meanwhile, the improvement of flow field characteristics after the addition of grids in crude oil tank drainage device was validated. These findings provide insights into the development of effective selection methods and serve as important references for oil-water separation process.
-
Theory of evapotranspiration. 2. Soil and intercepted water evaporation
Budagovskyi, Anatolij Ivanovič; Novák, Viliam
2011-01-01
Evaporation of water from the soil is described and quantified. Formation of the soil dry surface layer is quantitatively described, as a process resulting from the difference between the evaporation and upward soil water flux to the soil evaporating level. The results of evaporation analysis are generalized even for the case of water evaporation from the soil under canopy and interaction between evaporation rate and canopy transpiration is accounted for. Relationships describing evapotranspi...
-
Flow and geochemical modeling of drainage from Tomitaka mine, Miyazaki, Japan.
Yamaguchi, Kohei; Tomiyama, Shingo; Metugi, Hideya; Ii, Hiroyuki; Ueda, Akira
2015-10-01
The chemistry and flow of water in the abandoned Tomitaka mine of Miyazaki, western Japan were investigated. This mine is located in a non-ferrous metal deposit and acid mine drainage issues from it. The study was undertaken to estimate the quantities of mine drainage that needs to be treated in order to avoid acidification of local rivers, taking into account seasonal variations in rainfall. Numerical models aimed to reproduce observed water levels and fluxes and chemical variations of groundwater and mine drainage. Rock-water interactions that may explain the observed variations in water chemistry are proposed. The results show that: (1) rain water infiltrates into the deeper bedrock through a highly permeable zone formed largely by stopes that are partially filled with spoil from excavations (ore minerals and host rocks); (2) the water becomes acidic (pH from 3 to 4) as dissolved oxygen oxidizes pyrite; (3) along the flow path through the rocks, the redox potential of the water becomes reducing, such that pyrite becomes stable and pH of the mine drainage becomes neutral; and (4) upon leaving the mine, the drainage becomes acidic again due to oxidation of pyrite in the rocks. The present numerical model with considering of the geochemical characteristics can simulate the main variations in groundwater flow and water levels in and around the Tomitaka mine, and apply to the future treatment of the mine drainage. Copyright © 2015. Published by Elsevier B.V.
-
Directory of Open Access Journals (Sweden)
L. M. Timofeeva
2010-04-01
Full Text Available The analysis of consolidation process of condensed water-saturated clay soils of the floodable bridge-approach fill to the bridge across Kama River, erected by method called «Intensive technology», is presented. The method consists in the arrangement of drainage longitudinal and cross-section cuts for acceleration of consolidation of soils of the road bad and the base composed from the weak, strongly compressible water-saturated clay soils of different consistency.
-
Improvement of Water Movement in an Undulating Sandy Soil Prone to Water Repellency
Oostindie, K.; Dekker, L.W.; Wesseling, J.G.; Ritsema, C.J.
2011-01-01
The temporal dynamics of water repellency in soils strongly influence water flow. We investigated the variability of soil water content in a slight slope on a sandy fairway exhibiting water-repellent behavior. A time domain reflectometry (TDR) array of 60 probes measured water contents at 3-h
-
NUTRIENT BALANCE IN WATER HARVESTING SOILS
Directory of Open Access Journals (Sweden)
Díaz, F
2005-05-01
Full Text Available Dryland farming on Fuerteventura and Lanzarote (Canary Islands, Spain, which has an annual rainfall of less than 150 mm/year, has been based traditionally on water harvesting techniques (known locally as “gavias”. Periods of high productivity alternate with those of very low yield. The systems are sustainable in that they reduce erosive processes, contribute to soil and soil-water conservation and are largely responsible for maintaining the soil’s farming potential. In this paper we present the chemical fertility status and nutrient balance of soils in five “gavia” systems. The results are compared with those obtained in adjacent soils where this water harvesting technique is not used. The main crops are wheat, barley, maize, lentils and chick-peas. Since neither organic nor inorganic fertilisers are used, nutrients are derived mainly from sediments carried by runoff water. Nutrients are lost mainly through crop harvesting and harvest residues. The soils where water harvesting is used have lower salt and sodium in the exchange complex, are higher in carbon, nitrogen, copper and zinc and have similar phosphorous and potassium content. It is concluded that the systems improve the soil’s natural fertility and also that natural renovation of nutrients occurs thanks to the surface deposits of sediments, which mix with the arable layer. The system helps ensure adequate fertility levels, habitual in arid regions, thus allowing dryland farming to be carried out.
-
International Nuclear Information System (INIS)
Rieiro, I.; Trivino, V.; Gutierrez, T.; Munoz, J.; Larrea, M. T.
2013-01-01
This study asses the environmental pollution by metal release that takes place during prolonged exposures when metallic drink containers are accidentally settle in the soil in a uncontrolled way, For comparative purposes, the F111 steel and the aluminium alloy 3003, widely used for the fabrication of these containers, are also considered. A experimental design is proposed to simulate the environmental pollution during prolonged exposures. Analytical indicators have been obtained determining the metallic concentration from three types of mediums; water, water in presence of soil, and absorption-adsorption in soil. An analytical methodology has been developed by Atomic Emission Spectrometry with ICP as exciting source (ICP-OES) for metallic quantification. The method was validated using Certified Reference Materials (CRMs) of soil and water and the precision obtained varies from 5.39 to 5.86% and from 5.75 to 6.27%, respectively according to of the element studied. A statistical descriptive study followed by a factorial analysis (linear general model) has been carried out for the treatment of the experimental data packages. The metallic quantification for the three mediums shows that the soil inhibits metallic solubility in water. The process to make packages reduces in both cases their metallic cession. (Author)
-
Rozemeijer, J.C.; Visser, A.; Borren, W.; Winegram, M.; Velde, Y. van der; Klein, J.; Broers, H.P.
2016-01-01
High nitrogen (N) and phosphorus (P) fluxes from upstream agriculture threaten aquatic ecosystems in surface waters and estuaries, especially in areas characterized by high agricultural N and P inputs and densely drained catchments like the Netherlands. Controlled drainage has been recognized as an
-
How well will the Surface Water and Ocean Topography (SWOT) mission observe global reservoirs?
Solander, K.; Famiglietti, J. S.; David, C. H.; Reager, J. T., II
2014-12-01
Subsurface drainage is a very common practice in the agricultural U.S. Midwest. It is typically installed in poorly drained soils in order to enhance crop yields. The presence of tile drains creates a route for agrichemicals to travel and therefore negatively impacts stream water quality. This study estimated through end-member analyses the contributions of tile drainage, groundwater, and surface runoff to streamflow at the watershed scale based on continuously monitored data. Especial attention was devoted to quantifying tile drainage impact on watershed streamflow and nutrient export loads. Data analyzed includes streamflow, rainfall, soil moisture, shallow groundwater levels, in-stream nitrate+nitrite concentrations and specific conductance. Data were collected at a HUC12 watershed located in Northeast Iowa, USA. Approximately 60% of the total watershed area is devoted to agricultural activities and forest and grassland are the other two predominant land uses. Results show that approximately 20% of total annual streamflow comes from tile drainage and during rainfall events tile drainage contribution can go up to 30%. Furthermore, for most of the analyzed rainfall events groundwater responded faster and in a more dramatic fashion than tile drainage. The State of Iowa is currently carrying out a plan to reduce nutrients in Iowa waters and the Gulf of Mexico (Iowa Nutrient Reduction Strategy). The outcome of this investigation has the potential to assist in Best Management Practice (BMP) scenario selection and therefore help the state achieve water quality goals.
-
Effects of fire ash on soil water retention
Stoof, C.R.; Wesseling, J.G.; Ritsema, C.J.
2010-01-01
Despite the pronounced effect of fire on soil hydrological systems, information on the direct effect of fire on soil water retention characteristics is limited and contradictory. To increase understanding in this area, the effect of fire on soil water retention was evaluated using laboratory burning
-
Field, laboratory and estimated soil-water content limits
African Journals Online (AJOL)
2005-01-21
Jan 21, 2005 ... silt (0.002 to 0.05 mm) percentage to estimate the soil-water content at a given soil-water .... ar and br are the intercept and slope values of the regres- .... tions use the particle size classification of the South African Soil.
-
Fly ash dynamics in soil-water systems
International Nuclear Information System (INIS)
Sharma, S.; Fulekar, M.H.; Jayalakshmi, C.P.
1989-01-01
Studies regarding the effluents and coal ashes (or fly ash) resulting from coal burning are numerous, but their disposal and interactions with the soil and water systems and their detailed environmental impact assessment with concrete status reports on a global scale are scanty. Fly ash dynamics in soil and water systems are reviewed. After detailing the physical composition of fly ash, physicochemical changes in soil properties due to fly ash amendment are summarized. Areas covered include texture and bulk density, moisture retention, change in chemical equilibria, and effects of fly ash on soil microorganisms. Plant growth in amended soils is discussed, as well as plant uptake and accumulation of trace elements. In order to analyze the effect of fly ash on the physicochemical properties of water, several factors must be considered, including surface morphology of fly ash, pH of the ash sluice water, pH adjustments, leachability and solubility, and suspended ash and settling. The dynamics of fly ash in water systems is important due to pollution of groundwater resources from toxic components such as trace metals. Other factors summarized are bioaccumulation and biomagnification, human health effects of contaminants, and the impact of radionuclides in fly ash. Future research needs should focus on reduction of the environmental impact of fly ash and increasing utilization of fly ash as a soil amendment. 110 refs., 2 figs., 10 tabs
-
Chau, Henry Wai; Goh, Yit Kheng; Vujanovic, Vladimir; Si, Bing Cheng
2012-12-01
Soil water repellency (SWR) has a drastic impact on soil quality resulting in reduced infiltration, increased runoff, increased leaching, reduced plant growth, and increased soil erosion. One of the causes of SWR is hydrophobic fungal structures and exudates that change the soil-water relationship. The objective of this study was to determine whether SWR and infiltration could be manipulated through inoculation with fungi. The effect of fungi on SWR was investigated through inoculation of three fungal strains (hydrophilic -Fusarium proliferatum, chrono-amphiphilic -Trichoderma harzianum, and hydrophobic -Alternaria sp.) on a water repellent soil (WR-soil) and a wettable soil (W-soil). The change in SWR and infiltration was assessed by the water repellency index and cumulative infiltration respectively. F. proliferatum decreased the SWR on WR-soil and slightly increased SWR in W-soil, while Alternaria sp. increased SWR in both the W-soil and the WR-soil. Conversely T. harzianum increased the SWR in the W-soil and decreased the SWR in the WR-soil. All strains showed a decrease in infiltration in W-soil, while only the F. proliferatum and T. harzianum strain showed improvement in infiltration in the WR-soil. The ability of fungi to alter the SWR and enmesh soil particles results in changes to the infiltration dynamics in soil. Copyright © 2012 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.
-
Development of laundry drainage treatment system with ceramic ultra filter
International Nuclear Information System (INIS)
Kanda, Masanori; Kurahasi, Takafumi
1995-01-01
A compact laundry drainage treatment system (UF system hereafter) with a ceramic ultra filter membrane (UF membrane hereafter) has been developed to reduce radioactivity in laundry drainage from nuclear power plants. The UF membrane is made of sintered fine ceramic. The UF membrane has 0.01 μm fine pores, resulting in a durable, heat-resistant, and corrosion-resistant porous ceramic filter medium. A cross-flow system, laundry drainage is filtrated while it flows across the UF membrane, is used as the filtration method. This method creates less caking when compared to other methods. The UF membrane is back washed at regular intervals with permeated water to minimize caking of the filter. The UF membrane and cross-flow system provides long stable filtration. The ceramic UF membrane is strong enough to concentrate suspended solids in laundry drainage up to a weight concentration of 10%. The final concentrated laundry drainage can be treated in an incinerator. The performance of the UF system was checked using radioactive laundry drainage. The decontamination factor of the UF system was 25 or more. The laundry drainage treatment capacity and concentration ratio of the UF system, as well as the service life of the UF membrane were also checked by examination using simulated non-radioactive laundry drainage. Even though laundry drainage was concentrated 1000 times, the UF system showed good permeated water quality and permeated water flux. (author)
-
Effect of restoring soil hydrological poperties on water conservation
Moore, D.; Kostka, S.J.; Boerth, T.J.; Franklin, M.A.; Ritsema, C.J.; Dekker, L.W.; Oostindie, K.; Stoof, C.R.; Park, D.M.
2008-01-01
Water repellency in soil is more wide spread than previously thought ¿ and has a significant impact on irrigation efficiency and water conservation. Soil water repellency has been identified in many soil types under a wide array of climatic conditions world wide. Consequences include increased
-
National Research Council Canada - National Science Library
Fripp, Jon
2000-01-01
.... Acid mine drainage (AMD) can have severe impacts to aquatic resources, can stunt terrestrial plant growth and harm wetlands, contaminate groundwater, raise water treatment costs, and damage concrete and metal structures...
-
Directory of Open Access Journals (Sweden)
Ali Reza Kiani
2017-01-01
-saline water in every other row, respectively; T5 and T6= fixed and variable deficit irrigation with non-saline water in every other rows, respectively and T7= full irrigation with saline water. To create the desired water salinity (8 dS/m, non-saline well water (1.5 dS/m and drainage water (20–35 dS/m were blended in different proportions. A T-tape drip irrigation system (20 m in length was used in the field experiment. Results and Discussion: In general, corn yield in 2013 was about 1270 kg ha-1 higher than in 2012. From the weather records it can be seen that the second year was drier than the first year. Yield analysis showed that deficit irrigation treatments (T2, T5 & T6 and also alternate salinity treatments (T3 & T4 did not significantly difference. In other words, the deficit irrigation management had no effect on yield. Corn yield in T3 and T4 with 50% of saved fresh water was just reduced to 7 and 1 % of T1, respectively. As a result, comparing treatments T3 and T4 with full irrigation have shown that treatments T3 and T4 are the best option. Comparison of moisture distribution in deficit irrigation treatments showed the highest water content in surface and deep layers was related to the treatments T6 and T2, respectively. The distribution of salinity in the soil profile for treatments T3 and T4 showed that after two years of irrigation with saline water, there is the possibility of use saline water for corn production, but drainage and leaching of soil will need to maintain sustainability. Conclusion: Naturally, in water scarce areas that use some strategic management such as deficit irrigation or saline water use, there is available arable farmland to further develop the irrigated area, and thereby increase total production. According to the results of the two-years where there was a shortage of water to meet crop water requirement and saline water was not available, the use of deficit irrigation managements as described in this study can save fresh water
-
Sanchez-Garcia, Carmen; Urbanek, Emilia; Doerr, Stefan
2017-04-01
Rewetting of dry soils is known to cause a short-term CO2 pulse commonly known as the 'Birch effect'. The displacement of CO2 with water during the process of wetting has been recognised as one of the sources of this pulse. The 'Birch effect' has been extensively observed in many soils, but some studies report a lack of such phenomenon, suggesting soil water repellency (SWR) as a potential cause. Water infiltration in water repellent soils can be severely restricted, causing overland flow or increased preferential flow, resulting in only a small proportion of soil pores being filled with water and therefore small gas-water replacement during wetting. Despite the suggestions of a different response of CO2 fluxes to wetting under hydrophobic conditions, this theory has never been tested. The aim of this study is to test the hypothesis that CO2 pulse does not occur during rewetting of water repellent soils. Dry homogeneous soils at water-repellent and wettable status have been rewetted with different amounts of water. CO2 flux as a response to wetting has been continuously measured with the CO2 flux analyser. Delays in infiltration and non-uniform heterogeneous water flow were observed in water repellent soils, causing an altered response in the CO2 pulse in comparison to typically observed 'Birch effect' in wettable systems. The main conclusion from the study is that water repellency not only affects water relations in soil, but has also an impact on greenhouse gas production and transport and therefore should be included as an important parameter during the sites monitoring and modelling of gas fluxes.
-
Numerical Three-Dimensional Model of Airport Terminal Drainage System
Directory of Open Access Journals (Sweden)
Strzelecki Michał
2014-03-01
Full Text Available During the construction of an airport terminal it was found that as a result of the hydrostatic pressure of underground water the foundation plate of the building had dangerously shifted in the direction opposite to that of the gravitational forces. The only effective measure was to introduce a drainage system on the site. The complex geology of the area indicated that two independent drainage systems, i.e., a horizontal system in the Quaternary beds and a vertical system in the Tertiary water-bearing levels, were necessary. This paper presents numerical FEM calculations of the two drainage systems being part of the airport terminal drainaged esign. The computer simulation which was carried out took into consideration the actual effect of the drainage systems and their impact on the depression cone being formed in the two aquifers.
-
Seasonal changes of fertilizer impacts on agricultural drainage in a salinized area in Adana, Turkey
International Nuclear Information System (INIS)
Kume, T.; Akca, E.; Nakano, T.; Nagano, T.; Kapur, S.; Watanabe, T.
2010-01-01
Seasonal changes in the impacts of fertilizer on the composition of agricultural drainage water were examined by analyzing the 87 Sr/ 86 Sr isotope ratio and chemical composition of drainage water samples. Samples of drainage water were taken from the main drainage canals of the Lower Seyhan Irrigation Project, at sites designated as D10, D11, and D12. Plots of 87 Sr/ 86 Sr vs. 1/Sr indicated that the 87 Sr/ 86 Sr ratio of drainage water was positively related to those of fertilizer and irrigation water. The origins of Sr in two of the end-components were fertilizer and irrigation water. The data from the end-drain in winter suggested that the origin of Sr in the third end-component was fossil seawater. Analysis of a mixing model incorporating these three end-components showed that the origins of Sr in drainage differed markedly between summer and winter. Fertilizer made the greatest contribution to Sr in drainage water both in summer and winter, contributing 38-72% of total Sr in summer and 64-87% of total Sr in winter. In summer, fertilizer contributed 72% of total Sr in drainage water in D12, 44% in D10, and 38% in D11. This result implies that fertilizer was applied excessively at the D12 site. In winter, seawater accounted for 10% of Sr in drainage water in D12, whereas it accounted for 19-27% of Sr in drainage water in D10 and D11. Therefore, at least 70% of the salt in drainage water originates from fertilizer and irrigation water. At this study site, the salt originating from seawater is replaced by that from fertilizer and irrigation water, due to intensive agricultural management. The study site is a delta that lay on the ocean subsurface at least 3000 years ago, and therefore, was originally a primary salinization area. This result suggests that anthropogenic secondary salinization progressed over time via fertilizer and irrigation applications.
-
Water-quality assessment of the Smith River drainage basin, California and Oregon
Iwatsubo, Rick T.; Washabaugh, Donna S.
1982-01-01
A water-quality assessment of the Smith River drainage basin was made to provide a summary of the water-quality conditions including known or potential water-quality problems. Results of the study showed that the water quality of the Smith River is excellent and generally meets the water-quality objectives for the beneficial uses identified by the California Regional Water Quality Control Board, North Coast Region. Known and potential problems related to water quality include: Sedimentation resulting from both natural erosional processes and land-use activities such as timber harvest, road construction, and mining that accelerate the erosional processes; bacterial contamination of surface and ground waters from inundated septic tanks and drainfields, and grazing activities; industrial spills which have resulted in fish kills and oil residues; high concetrations of iron in ground water; log and debris jams creating fish migration barriers; and pesticide and trace-element contamination from timber-harvest and mining activities, respectively. Future studies are needed to establish: (1) a sustained long-term monitoring program to provide a broad coverage of water-quality conditions in order to define long-term water-quality trends; and (2) interpretive studies to determine the source of known and potential water-quality problems. (USGS)
-
Directory of Open Access Journals (Sweden)
Etienne Goulet
2006-06-01
Full Text Available The classical techniques that allow to quantify the soil water status such as the gravimetric method or the use of neutrons probes do not give access to the volume of soil explored by the plant root system. On the contrary, electric tomography can be used to have a global vision on the water exchange area between soil and plant. The measurement of soil electric resistivity, as a non destructive, spatially integrative technique, has recently been introduced into viticulture. The use of performing equipment and adapted software allows for rapid data processing and gives the possibility to spatialize the variations of soil texture or humidity in two or three dimensions. Soil electric resistivity has been tested for the last three years at the Experimental Unit on Grapevine and Vine, INRA, Angers, France, to study the water supply to the vine in different “terroir” conditions. Resistivity measurements were carried out with the resistivity meter Syscal R1+ (Iris Instruments, France equipped with 21 electrodes. Those electrodes were lined up on the soil surface in a direction perpendiculary to 5 grapevine rows with an electrode spacing of 0.5 m. and a dipole-dipole arrangement. Resistivity measurements were performed on the same place at different times in order to study soil moisture variations. This experimental set up has permitted to visualise the soil stratification and individualize some positive electric anomalies corresponding to preferential drying ; this desiccation could be attributed to grapevine root activity. The soil bulk subject to the water up-take could be defined more precisely and in some types of soil, available water may even be quantified. Terroir effect on grapevine root activity has also been shown up on two different experimental parcels through electric tomography and first results indicate that it is possible to monitor the effects of soil management (inter-row grassing or different rootstocks on the water supply to the
-
International Nuclear Information System (INIS)
McCoy, E.L.; Boersma, L.; Ekasingh, M.
1990-01-01
The influence of water stress at two soil temperatures on allocation of net photoassimilated carbon in soybean (Glycine max [L.] Merr.) was investigated using compartmental analysis. The experimental phase employed classical 14 C labeling methodology with plants equilibrated at soil water potentials of -0.04, -0.25 and -0.50 MPa; and soil temperatures of 25 and 10C. Carbon immobilization in the shoot apex generally followed leaf elongation rates with decreases in both parameters at increasing water stress at both soil temperatures. However, where moderate water stress resulted in dramatic declines in leaf elongation rates, carbon immobilization rates were sharply decreased only at severe water stress levels. Carbon immobilization was decreased in the roots and nodules of the nonwater stressed treatment by the lower soil temperature. This relation was reversed with severe water stress, and carbon immobilization in the roots and nodules was increased at the lower soil temperature. Apparently, the increased demand for growth and/or carbon storage in these tissues with increased water stress overcame the low soil temperature limitations. Both carbon pool sizes and partitioning of carbon to the sink tissues increased with moderate water stress at 25C soil temperature. Increased pool sizes were consistent with whole plant osmotic adjustment at moderate water stress. Increased partitioning to the sinks was consistent with carbon translocation processes being less severely influenced by water stress than is photosynthesis
-
Moisture variability resulting from water repellency in Dutch soils
Dekker, L.W.
1998-01-01
The present study suggests that many soils in the Netherlands, in natural as well as in agricultural areas, may be water repellent to some degree, challenging the common perception that soil water repellency is only an interesting aberration. When dry, water repellent soils resist or retard
-
Effects of soil management techniques on soil water erosion in apricot orchards.
Keesstra, Saskia; Pereira, Paulo; Novara, Agata; Brevik, Eric C; Azorin-Molina, Cesar; Parras-Alcántara, Luis; Jordán, Antonio; Cerdà, Artemi
2016-05-01
Soil erosion is extreme in Mediterranean orchards due to management impact, high rainfall intensities, steep slopes and erodible parent material. Vall d'Albaida is a traditional fruit production area which, due to the Mediterranean climate and marly soils, produces sweet fruits. However, these highly productive soils are left bare under the prevailing land management and marly soils are vulnerable to soil water erosion when left bare. In this paper we study the impact of different agricultural land management strategies on soil properties (bulk density, soil organic matter, soil moisture), soil water erosion and runoff, by means of simulated rainfall experiments and soil analyses. Three representative land managements (tillage/herbicide/covered with vegetation) were selected, where 20 paired plots (60 plots) were established to determine soil losses and runoff. The simulated rainfall was carried out at 55mmh(-1) in the summer of 2013 (soil moisture) for one hour on 0.25m(2) circular plots. The results showed that vegetation cover, soil moisture and organic matter were significantly higher in covered plots than in tilled and herbicide treated plots. However, runoff coefficient, total runoff, sediment yield and soil erosion were significantly higher in herbicide treated plots compared to the others. Runoff sediment concentration was significantly higher in tilled plots. The lowest values were identified in covered plots. Overall, tillage, but especially herbicide treatment, decreased vegetation cover, soil moisture, soil organic matter, and increased bulk density, runoff coefficient, total runoff, sediment yield and soil erosion. Soil erosion was extremely high in herbicide plots with 0.91Mgha(-1)h(-1) of soil lost; in the tilled fields erosion rates were lower with 0.51Mgha(-1)h(-1). Covered soil showed an erosion rate of 0.02Mgha(-1)h(-1). These results showed that agricultural management influenced water and sediment dynamics and that tillage and herbicide
-
The economic pre-treatment of coal mine drainage water with caustic and ozone.
Boyden, B H; Nador, L; Addleman, S; Jeston, L
2017-09-01
Coal mine drainage waters are low in pH with varying amounts of iron and manganese and are generally brackish. The Austar Coal Mine in NSW, Australia, sought alternatives to their current lime dosing as the pre-treatment before the downstream reverse osmosis plant. Undesirable operating aspects of the current system include manganese and gypsum scaling/fouling, the need for anti-scalants and reduced water recovery. Thirteen processes for acid mine drainage were initially considered. The preferred process of caustic and ozone for Mn(II) oxidation was pilot tested at up to 0.74 kL/hr at the mine site. Under proper conditions and no aeration, about 81 per cent of the Fe could be removed (initially at 156 mg/L) as green rust. Supplemental aeration followed first-order kinetics and allowed 99.9 per cent Fe(II) oxidation and removal but only with a hydraulic residence time of about 47 minutes. The addition of supplemental Cu catalyst improved Fe removal. Ozone applied after caustic was effective in stoichiometrically oxidising recalcitrant Mn(II) and any remaining Fe(II). Control of the ozonation was achieved using the oxidation reduction potential during oxidation of the Mn(II) species. The use of caustic, followed by ozone, proved economically comparable to the current lime pre-treatment.
-
SOIL WATER BALANCE APPROACH IN ROOT ZONE OF MAIZE (95 ...
African Journals Online (AJOL)
DR. AMINU
It is usual practice to use available soil water content as a criterion for deciding when irrigation is needed. Soil water content is determined by using soil measuring techniques (capacitance probe) that describe the depletion of available soil water see fig1 and 2. The irrigation scheduling is based on the water treatment (i.e. ...
-
Transport of mecoprop from agricultural soils to an adjacent salt marsh
International Nuclear Information System (INIS)
Fletcher, Caroline A.; Scrimshaw, Mark D.; Lester, John N.
2004-01-01
Salt marshes are important ecological areas and play a significant role in coastal flood defence schemes. In many areas of the UK they are adjacent to agricultural areas utilised for the growth of cereal crops, for which mecoprop is used as a selective herbicide in the control of broad-leafed weeds. This study measured concentrations of mecoprop in soils, drainage ditch waters and sediments and salt marsh sediments over a period of 138 days following spring application. Soil concentrations of up to 1827 μg/g were recorded after application, which demonstrated a half life for mecoprop of from 9 to 12 days, with first order kinetics. However, a major rainfall event 9 days after application resulted in significant transport of herbicide to the salt marsh via subsurface field drains, drainage ditches and discharge sluice. Mecoprop concentrations of up to 386 μg/l observed in water samples were above UK guidelines
-
Long-term monitoring of nitrate transport to drainage from three agricultural clayey till fields
Ernstsen, V.; Olsen, P.; Rosenbom, A. E.
2015-08-01
The application of nitrogen (N) fertilisers to crops grown on tile-drained fields is required to sustain most modern crop production, but it poses a risk to the aquatic environment since tile drains facilitate rapid transport pathways with no significant reduction in nitrate. To maintain the water quality of the aquatic environment and the provision of food from highly efficient agriculture in line with the EU's Water Framework Directive and Nitrates Directive, field-scale knowledge is essential for introducing water management actions on-field or off-field and producing an optimal differentiated N-regulation in future. This study strives to provide such knowledge by evaluating on 11 years of nitrate-N concentration measurements in drainage from three subsurface-drained clayey till fields (1.3-2.3 ha) representing approximately 71 % of the surface sediments in Denmark dominated by clay. The fields differ in their inherent hydrogeological field settings (e.g. soil-type, geology, climate, drainage and groundwater table) and the agricultural management of the fields (e.g. crop type, type of N fertilisers and agricultural practices). The evaluation revealed three types of clayey till fields characterised by: (i) low net precipitation, high concentration of nitrate-N, and short-term low intensity drainage at air temperatures often below 5 °C; (ii) medium net precipitation, medium concentration of nitrate-N, and short-term medium-intensity drainage at air temperatures often above 5 °C; and (iii) high net precipitation, low concentration of nitrate-N and long-term high intensity drainage at air temperatures above 5 °C. For each type, on-field water management actions, such as the selection of crop types and introduction of catch crops, appeared relevant, whereas off-field actions only seemed relevant for the latter two field types given the temperature-dependent reduction potential of nitrate off-field. This initial well-documented field-scale knowledge from fields
-
Soil water sensor response to bulk electrical conductivity
Soil water monitoring using electromagnetic (EM) sensors can facilitate observations of water content at high temporal and spatial resolutions. These sensors measure soil dielectric permittivity (Ka) which is largely a function of volumetric water content. However, bulk electrical conductivity BEC c...
-
Water table lowering to improve excavation performance and to reduce acid mine drainage
International Nuclear Information System (INIS)
Koppe, J.C.; Costa, J.F.; Laurent, O. Jr.
1995-01-01
This paper analyses the water table level fluctuations using wells located adjacent to the stripping cuts at the Butia-Leste coal mine, southernmost of Brazil. Piezometers monitored the water table fluctuations. Geological mapping provided additional information aiding the interpretation of the results. A contouring software was also used as tool to aid the interpretation of the data and the results visualisation. The parameters necessary in selecting the location of the wells and pumping volumes were calculated from the data obtained in the water table lowering tests. The results were used to minimise two main problems: the generation of acid mine drainage and the reduction of the excavation performance of the fleet used in overburden removal. 7 refs., 5 figs., 3 tabs
-
Old carbon efflux from tropical peat swamp drainage waters
Vihermaa, Leena; Waldron, Susan; Evers, Stephanie; Garnett, Mark; Newton, Jason
2014-05-01
Tropical peatlands constitute ~12% of the global peatland carbon pool, and of this 10% is in Malaysia1. Due to rising demand for food and biofuels, large areas of peat swamp forest ecosystems have been converted to plantation in Southeast Asia and are being subjected to degradation, drainage and fire, changing their carbon fluxes eg.2,3. Dissolved organic carbon (DOC) lost from disturbed tropical peat can be derived from deep within the peat column and be aged from centuries to millennia4 contributing to aquatic release and cycling of old carbon. Here we present the results of a field campaign to the Raja Musa Peat Swamp Forest Reserve in N. Selangor Malaysia, which has been selectively logged for 80 years before being granted timber reserve status. We measured CO2 and CH4efflux rates from drainage systems with different treatment history, and radiocarbon dated the evasion CO2 and associated [DOC]. We also collected water chemistry and stable isotope data from the sites. During our sampling in the dry season CO2 efflux rates ranged from 0.8 - 13.6 μmol m-2 s-1. Sediments in the channel bottom contained CH4 that appeared to be primarily lost by ebullition, leading to sporadic CH4 efflux. However, dissolved CH4 was also observed in water samples collected from these systems. The CO2 efflux was aged up to 582±37 years BP (0 BP = AD 1950) with the associated DOC aged 495±35 years BP. Both DOC and evasion CO2 were most 14C-enriched (i.e. younger) at the least disturbed site, and implied a substantial component of recently fixed carbon. In contrast, CO2 and DOC from the other sites had older 14C ages, indicating disturbance as the trigger for the loss of old carbon. 1Page et al., 2010 2Hooijer et al., 2010 3Kimberly et al., 2012 4Moore et al., 2013
-
Theoretical study of soil water balance and process of soil moisture evaporation
Directory of Open Access Journals (Sweden)
Yu. A. Savel'ev
2017-01-01
Full Text Available Nearly a half of all grain production in the Russian Federation is grown in dry regions. But crop production efficiency there depends on amount of moisture, available to plants. However deficit of soil moisture is caused not only by a lack of an atmospheric precipitation, but also inefficient water saving: losses reach 70 percent. With respect thereto it is important to reveal the factors influencing intensity of soil moisture evaporation and to develop methods of decrease in unproductive moisture losses due to evaporation. The authors researched soil water balance theoretically and determined the functional dependences of moisture loss on evaporation. Intensity of moisture evaporation depends on physicomechanical characteristics of the soil, a consistence of its surface and weather conditions. To decrease losses of moisture for evaporation it is necessary, first, to improve quality of crumbling of the soil and therefore to reduce the evaporating surface of the soil. Secondly - to create the protective mulching layer which will allow to enhance albedo of the soil and to reduce its temperature that together will reduce unproductive evaporative water losses and will increase its inflow in case of condensation from air vapors. The most widespread types of soil cultivation are considered: disk plowing and stubble mulch plowing. Agricultural background «no tillage» was chosen as a control. Subsoil mulching tillage has an essential advantage in a storage of soil moisture. So, storage of soil moisture after a disking and in control (without tillage decreased respectively by 24.9 and 19.8 mm while at the mulching tillage this indicator revised down by only 15.6 mm. The mulching layer has lower heat conductivity that provides decrease in unproductive evaporative water losses.
-
International Nuclear Information System (INIS)
2009-06-01
After a brief presentation of the coal mining and electricity production activities of the SONICHAR, and the related concerns about the environmental impacts of these activities, this document reports analyses performed on mine drainage waters, and on water samples coming from a pit located upstream the mine effluent and from a pit close to this effluent. Different sulfates and metals display much higher contents than those admitted for drinkable water in Europe
-
Hendriks, Rob F. A.; van den Akker, Jan J. A.
2017-04-01
Effectiveness of submerged drains in reducing subsidence of peat soils in agricultural use, and their effects on water management and nutrient loading of surface water: modelling of a case study in the western peat soil area of The Netherlands In the Netherlands, about 8% of the area is covered by peat soils. Most of these soils are in use for dairy farming and, consequently, are drained. Drainage causes decomposition of peat by oxidation and accordingly leads to surface subsidence and greenhouse gas emission. Submerged drains that enhance submerged infiltration of water from ditches during the dry and warm summer half year were, and are still, studied in The Netherlands as a promising tool for reducing peat decomposition by raising groundwater levels. For this purpose, several pilot field studies in the Western part of the Dutch peat area were conducted. Besides the effectiveness of submerged drains in reducing peat decomposition and subsidence by raising groundwater tables, some other relevant or expected effects of these drains were studied. Most important of these are water management and loading of surface water with nutrients nitrogen, phosphorus and sulphate. Because most of these parameters are not easy to assess and all of them are strongly depending on the meteorological conditions during the field studies some of these studies were modelled. The SWAP model was used for evaluating the hydrological results on groundwater table and water discharge and recharge. Effects of submerged drains were assessed by comparing the results of fields with and without drains. An empirical relation between deepest groundwater table and subsidence was used to convert effects on groundwater table to effects on subsidence. With the SWAP-ANIMO model nutrient loading of surface water was modelled on the basis of field results on nutrient concentrations . Calibrated models were used to assess effects in the present situation, as thirty-year averages, under extreme weather
-
Pore-water chemistry explains zinc phytotoxicity in soil.
Kader, Mohammed; Lamb, Dane T; Correll, Ray; Megharaj, Mallavarapu; Naidu, Ravi
2015-12-01
Zinc (Zn) is a widespread soil contaminant arising from a numerous anthropogenic sources. However, adequately predicting toxicity of Zn to ecological receptors remains difficult due to the complexity of soil characteristics. In this study, we examined solid-solution partitioning using pore-water data and toxicity of Zn to cucumber (Cucumis sativus L.) in spiked soils. Pore-water effective concentration (ECx, x=10%, 20% and 50% reduction) values were negatively related to pH, indicating lower Zn pore water concentration were needed to cause phytotoxicity at high pH soils. Total dissolved zinc (Znpw) and free zinc (Zn(2+)) in soil-pore water successfully described 78% and 80.3% of the variation in relative growth (%) in the full dataset. When the complete data set was used (10 soils), the estimated EC50pw was 450 and 79.2 µM for Znpw and Zn(2+), respectively. Total added Zn, soil pore water pH (pHpw) and dissolve organic carbon (DOC) were the best predictors of Znpw and Zn(2+) in pore-water. The EC10 (total loading) values ranged from 179 to 5214 mg/kg, depending on soil type. Only pH measurements in soil were related to ECx total Zn data. The strongest relationship to ECx overall was pHca, although pHw and pHpw were in general related to Zn ECx. Similarly, when a solution-only model was used to predict Zn in shoot, DOC was negatively related to Zn in shoot, indicating a reduction in uptake/ translocation of Zn from solution with increasing DOC. Copyright © 2015 Elsevier Inc. All rights reserved.
-
Metal cycling during sediment early diagenesis in a water reservoir affected by acid mine drainage
DEFF Research Database (Denmark)
Torres, Ester; Ayora, Carlos; Canovas, C. R.
2013-01-01
The discharge of acid mine drainage (AMD) into a reservoir may seriously affect the water quality. To investigate the metal transfer between the water and the sediment, three cores were collected from the Sancho Reservoir (Iberian Pyrite Belt, SW Spain) during different seasons: turnover event......; oxic, stratified period; anoxic and under shallow perennially oxic conditions. The cores were sliced in an oxygen-free atmosphere, after which pore water was extracted by centrifugation and analyzed. A sequential extraction was then applied to the sediments to extract the water-soluble, monosulfide......, low crystallinity Fe(III)-oxyhydroxide, crystalline Fe(III)-oxide, organic, pyrite and residual phases. The results showed that, despite the acidic chemistry of the water column (pH
-
Energy Technology Data Exchange (ETDEWEB)
Diez, J. A.; Arauzo, M.; Hernaiz, P.; Sanz, A.
2010-07-01
In experiments carried out in greenhouses, some authors have shown that ammonium sulphate induces greater soil acidity and salinity than other sources of N. Moreover, nitrification inhibitors (NI) tend to cause ammonium to accumulate in soil by retarding its oxidation to nitrate. This accumulated ammonium would also have an effect on soil salinity. Consequently, the aim of this paper was to evaluate the soil and leaching water salinization effects associated with adding NI, dicyandiamide (DCD) and dimethylpyrazole-phosphate (DMPP) to ammonium sulphate nitrate (ASN) fertilizer. This experiment was carried out in the field with an irrigated maize crop. Drainage and Na concentration were measured during both seasons (2006 and 2007) and leached Na was determined. The treatments with NI (DCD and DMPP) were associated with greater Na concentrations in soil solutions and consequently higher rates of Na leaching (in 2007, ASN-DCD 1,292 kg Na ha{sup -}1, ASN-DMPP 1,019 kg Na ha{sup -}1). A treatment involving only ASN also increased the Na concentration in soil and the amount of Na leached in relation to the Control (in 2007, ASN 928 kg Na ha{sup -}1 and Control 587 kg Na ha{sup -}1). The increase in the ammonium concentration in the soil due to the NI treatments could have been the result of the displacement of Na ions from the soil exchange complex through a process which finally led to an increase in soil salinity. Treatments including ammonium fertilizer formulated with NI produced a greater degree of soil salinization due to the presence of ammonium from the fertilizer and accumulated ammonium from the nitrification inhibition. (Author) 31 refs.
-
Stability performance and interface shear strength of geocomposite drain/soil systems
Othman, Maidiana; Frost, Matthew; Dixon, Neil
2018-02-01
Landfill covers are designed as impermeable caps on top of waste containment facilities after the completion of landfill operations. Geocomposite drain (GD) materials consist of a geonet or geospacer (as a drainage core) sandwiched between non-woven geotextiles that act as separators and filters. GD provides a drainage function as part of the cover system. The stability performance of landfill cover system is largely controlled by the interface shear strength mobilized between the elements of the cover. If a GD is used, the interface shear strength properties between the upper surface of the GD and the overlying soil may govern stability of the system. It is not uncommon for fine grained materials to be used as cover soils. In these cases, understanding soil softening issues at the soil interface with the non-woven geotextile is important. Such softening can be caused by capillary break behaviour and build-up of water pressures from the toe of the drain upwards into the cover soil. The interaction processes to allow water flow into a GD core through the soil-geotextile interface is very complex. This paper reports the main behaviour of in-situ interface shear strength of soil-GD using field measurements on the trial landfill cover at Bletchley, UK. The soil softening at the interface due to soaked behaviour show a reduction in interface shear strength and this aspect should be emphasized in design specifications and construction control. The results also help to increase confidence in the understanding of the implications for design of cover systems.
-
Steinberg, S. L.; Henninger, D. L.
1997-01-01
Water transport through a microporous tube-soil-plant system was investigated by measuring the response of soil and plant water status to step change reductions in the water pressure within the tubes. Soybeans were germinated and grown in a porous ceramic 'soil' at a porous tube water pressure of -0.5 kpa for 28 d. During this time, the soil matric potential was nearly in equilibrium with tube water pressure. Water pressure in the porous tubes was then reduced to either -1.0, -1.5 or -2.0 kPa. Sap flow rates, leaf conductance and soil, root and leaf water potentials were measured before and after this change. A reduction in porous tube water pressure from -0.5 to -1.0 or -1.5 kPa did not result in any significant change in soil or plant water status. A reduction in porous tube water pressure to -2.0 kPa resulted in significant reductions in sap flow, leaf conductance, and soil, root and leaf water potentials. Hydraulic conductance, calculated as the transpiration rate/delta psi between two points in the water transport pathway, was used to analyse water transport through the tube-soil-plant continuum. At porous tube water pressures of -0.5 to-1.5 kPa soil moisture was readily available and hydraulic conductance of the plant limited water transport. At -2.0 kPa, hydraulic conductance of the bulk soil was the dominant factor in water movement.
-
Speelman, S.; Haese, D' M.F.C.; Haese, D' L.
2011-01-01
This paper focuses on estimating the effect of drainage water reuse on the technical efficiency of small-scale vegetable growers in South Africa applying a data envelopment analysis (DEA). In the semi-arid North West Province of South Africa water scarcity and the soon to be implemented water
-
Song, Qing; Yanful, Ernest K.
2010-05-01
Engineered soil covers provide an option to mitigate acid rock drainage through reduced water flow and gaseous oxygen influx to underlying mine waste. Channels such as fissures, cracks or fractures developed in the barrier may influence the long-term performance of the soil cover. However, limited published information is available on the extent to which soil cover performance is impacted by these fissures and cracks. This study was conducted to investigate the effect of channelling in a barrier layer on water flow and oxygen transport in a soil cover. Two inclined (a slope of 20%) multilayer soil covers were examined under laboratory conditions. One cover had a 10-cm wide sand-filled channel in a compacted barrier layer (silty clay) at the upslope section, while the other cover was a normal one without the channel pathway. The soil covers were installed in plastic boxes measuring 120 cm × 120 cm × 25 cm (width × height × thickness). The sand-filled channel was designed to represent the aggregate of fissures and cracks that may be present in the compacted barrier. The soil covers were subjected to controlled drying and wetting periods selected to simulate field situation at the Whistle mine site near Capreol, Ontario, Canada. The measured results indicated that interflow decreased from 72.8% of the total precipitation in the soil cover without channel flow to 35.3% in the cover with channel flow, and percolation increased from zero in the normal soil cover to 43.0% of the total precipitation in the cover with channel flow. Gaseous oxygen transfer into the waste rock below the cover soils was 1091 times greater in the cover with channel than in the soil cover without channel. The channel pathway present in the barrier layer acted as a major passage for water movement and gaseous oxygen diffusion into the waste rock layer, thus decreasing the performance of the soil cover. The spacing of the channel with respect to the length of the test box is similar to those
-
Modeling of subglacial hydrological development following rapid supraglacial lake drainage
Dow, C F; Kulessa, B; Rutt, I C; Tsai, V C; Pimentel, S; Doyle, S H; van As, D; Lindb?ck, K; Pettersson, R; Jones, G A; Hubbard, A
2015-01-01
The rapid drainage of supraglacial lakes injects substantial volumes of water to the bed of the Greenland ice sheet over short timescales. The effect of these water pulses on the development of basal hydrological systems is largely unknown. To address this, we develop a lake drainage model incorporating both (1) a subglacial radial flux element driven by elastic hydraulic jacking and (2) downstream drainage through a linked channelized and distributed system. Here we present the model and exa...
-
Remote Sensing Monitoring of Changes in Soil Salinity: A Case Study in Inner Mongolia, China
Directory of Open Access Journals (Sweden)
Jingwei Wu
2008-11-01
Full Text Available This study used archived remote sensing images to depict the history of changes in soil salinity in the Hetao Irrigation District in Inner Mongolia, China, with the purpose of linking these changes with land and water management practices and to draw lessons for salinity control. Most data came from LANDSAT satellite images taken in 1973, 1977, 1988, 1991, 1996, 2001, and 2006. In these years salt-affected areas were detected using a normal supervised classification method. Corresponding cropped areas were detected from NVDI (Normalized Difference Vegetation Index values using an unsupervised method. Field samples and agricultural statistics were used to estimate the accuracy of the classification. Historical data concerning irrigation/drainage and the groundwater table were used to analyze the relation between changes in soil salinity and land and water management practices. Results showed that: (1 the overall accuracy of remote sensing in detecting soil salinity was 90.2%, and in detecting cropped area, 98%; (2 the installation/innovation of the drainage system did help to control salinity; and (3 a low ratio of cropped land helped control salinity in the Hetao Irrigation District. These findings suggest that remote sensing is a useful tool to detect soil salinity and has potential in evaluating and improving land and water management practices.
-
Remote Sensing Monitoring of Changes in Soil Salinity: A Case Study in Inner Mongolia, China.
Wu, Jingwei; Vincent, Bernard; Yang, Jinzhong; Bouarfa, Sami; Vidal, Alain
2008-11-07
This study used archived remote sensing images to depict the history of changes in soil salinity in the Hetao Irrigation District in Inner Mongolia, China, with the purpose of linking these changes with land and water management practices and to draw lessons for salinity control. Most data came from LANDSAT satellite images taken in 1973, 1977, 1988, 1991, 1996, 2001, and 2006. In these years salt-affected areas were detected using a normal supervised classification method. Corresponding cropped areas were detected from NVDI (Normalized Difference Vegetation Index) values using an unsupervised method. Field samples and agricultural statistics were used to estimate the accuracy of the classification. Historical data concerning irrigation/drainage and the groundwater table were used to analyze the relation between changes in soil salinity and land and water management practices. Results showed that: (1) the overall accuracy of remote sensing in detecting soil salinity was 90.2%, and in detecting cropped area, 98%; (2) the installation/innovation of the drainage system did help to control salinity; and (3) a low ratio of cropped land helped control salinity in the Hetao Irrigation District. These findings suggest that remote sensing is a useful tool to detect soil salinity and has potential in evaluating and improving land and water management practices.
-
Development of soil water regime under spruce stands
Directory of Open Access Journals (Sweden)
Tužinský Ladislav
2017-06-01
Full Text Available The aim of this paper is to analyse the water regime of soils under spruce ecosystems in relation to long-lasting humid and drought periods in the growing seasons 1991-2013. The dominant interval humidity in observing growing seasons is semiuvidic interval with soil moisture between hydro-limits maximal capillary capacity (MCC and point of diminished availability (PDA. Gravitationally seepage concentrated from accumulated winter season, water from melting snow and existing atmospheric precipitation occurs in the soil only at the beginning of the growing season. The supplies of soil water are significantly decreasing in the warm climate and precipitant deficient days. The greatest danger from drought threatens Norway spruce during the summer months and it depends on the duration of dry days, water supply at the beginning of the dry days, air temperature and the intensity of evapotranspiration. In the surface layers of the soil, with the maximum occurrence of active roots, the water in semiarid interval area between hydro-limits PDA and wilting point (WP decreases during the summer months. In the culminating phase occurs the drying to moisture state with capillary stationary and the insufficient supply of available water for the plants. Physiological weakening of Norway spruce caused by set of outlay components of the water balance is partially reduced by delivering of water by capillary action from deeper horizons. In extremely dry periods, soil moisture is decreasing also throughout the soil profile (0-100 cm into the bottom third of the variation margin hydro-limits MCC-PDA in the category of capillary less moving and for plants of low supply of usable water (60-90 mm. The issue of deteriorated health state of spruce ecosystems is considered to be actual. Changes and developments of hydropedological conditions which interfere the mountain forests represent the increasing danger of the drought for the spruce.
-
Smith, Kirk P.
2015-01-01
Streamflow and concentrations of sodium and chloride estimated from records of specific conductance were used to calculate loads of sodium and chloride during water year (WY) 2013 (October 1, 2012, through September 30, 2013) for tributaries to the Scituate Reservoir, Rhode Island. Streamflow and water-quality data used in the study were collected by the U.S. Geological Survey (USGS) or the Providence Water Supply Board (PWSB) in the cooperative study. Streamflow was measured or estimated by the USGS following standard methods at 23 streamgages; 14 of these streamgages are equipped with instrumentation capable of continuously monitoring water level, specific conductance, and water temperature. Water-quality samples were collected at 37 sampling stations by the PWSB and at 14 continuous-record streamgages by the USGS during WY 2013 as part of a long-term sampling program; all stations are in the Scituate Reservoir drainage area. Water-quality data collected by the PWSB are summarized by using values of central tendency and are used, in combination with measured (or estimated) streamflows, to calculate loads and yields (loads per unit area) of selected water-quality constituents for WY 2013.
-
PASSIVE TREATMENT OF ACID ROCK DRAINAGE FROM A SUBSURFACE MINE
Acidic, metal-contaminated drainages are a critical problem facing many areas of the world. Acid rock drainage results when metal sulfide minerals, particularly pyrite, are oxidized by exposure to oxygen and water. The deleterious effects of these drainages on receiving streams a...
-
Soil water sensors:Problems, advances and potential for irrigation scheduling
Irrigation water management has to do with the appropriate application of water to soils, in terms of amounts, rates, and timing to satisfy crop water demands, while protecting the soil and water resources from degradation. In this regard, sensors can be used to monitor the soil water status; and so...
-
Kulhavý, Zbyněk; Fučík, Petr
2015-04-01
In this paper, issues of agricultural drainage systems are introduced and discussed from the views of their former, current and future roles and functioning in the Czech Republic (CR). A methodologically disparate survey was done on thirty-nine model localities in CR with different intensity and state of land drainage systems, aimed at description of commonly occurred problems and possible adaptations of agricultural drainage as perceived by farmers, land owners, landscape managers or by protective water management. The survey was focused on technical state of drainage, fragmentation of land ownership within drained areas as well as on possible conflicts between agricultural and environmental interests in a landscape. Achieved results confirmed that there is obviously an increasing need to reassess some functions of prevailingly single-purpose agricultural drainage systems. Drainage intensity and detected unfavourable technical state of drainage systems as well as the risks connected with the anticipated climate change from the view of possible water scarcity claims for a complex solution. An array of adaptation options for agricultural drainage systems is presented, aiming at enhancement of water retention time and improvement of water quality. It encompasses additional flow-controlling measures on tiles or ditches, or facilities for making selected parts of a drainage system inoperable in order to retain or slow down the drainage runoff, to establish water accumulation zones and to enhance water self-cleaning processes. However, it was revealed that the question of landowner parcels fragmentation on drained land in CR would dramatically complicate design and realization of these measures. Presented solutions and findings are propounded with a respect to contemporary and future state policies and international strategies for sustainable agriculture, water management and environment.
-
Real-Time Water Quality Monitoring and Habitat Assessment in theSan Luis National Wildlife Refuge
Energy Technology Data Exchange (ETDEWEB)
Quinn, Nigel W.T.; Hanlon, Jeremy S.; Burns, Josephine R.; Stromayer, Karl A.K.; Jordan, Brandon M.; Ennis, Mike J.; Woolington,Dennis W.
2005-08-28
The project report describes a two year experiment to control wetland drainage to the San Joaquin River of California from the San Luis National Wildlife Refuge using a decision support system for real-time water quality management. This system required the installation and operation of one inlet and three drainage flow and water quality monitoring stations which allowed a simple mass balance model to be developed of the seasonally managed wetlands in the study area. Remote sensing methods were developed to document long-term trends in wetland moist soil vegetation and soil salinity in response to management options such as delaying the initiation of seasonal wetland drainage. These environmental management tools provide wetland managers with some of the tools necessary to improve salinity conditions in the San Joaquin River and improve compliance with State mandated salinity objectives without inflicting long-term harm on the wild fowl habitat resource.
-
Field-scale water balance closure in seasonally frozen conditions
Directory of Open Access Journals (Sweden)
X. Pan
2017-11-01
Full Text Available Hydrological water balance closure is a simple concept, yet in practice it is uncommon to measure every significant term independently in the field. Here we demonstrate the degree to which the field-scale water balance can be closed using only routine field observations in a seasonally frozen prairie pasture field site in Saskatchewan, Canada. Arrays of snow and soil moisture measurements were combined with a precipitation gauge and flux tower evapotranspiration estimates. We consider three hydrologically distinct periods: the snow accumulation period over the winter, the snowmelt period in spring, and the summer growing season. In each period, we attempt to quantify the residual between net precipitation (precipitation minus evaporation and the change in field-scale storage (snow and soil moisture, while accounting for measurement uncertainties. When the residual is negligible, a simple 1-D water balance with no net drainage is adequate. When the residual is non-negligible, we must find additional processes to explain the result. We identify the hydrological fluxes which confound the 1-D water balance assumptions during different periods of the year, notably blowing snow and frozen soil moisture redistribution during the snow accumulation period, and snowmelt runoff and soil drainage during the melt period. Challenges associated with quantifying these processes, as well as uncertainties in the measurable quantities, caution against the common use of water balance residuals to estimate fluxes and constrain models in such a complex environment.
-
Activated carbon amendment to sequester PAHs in contaminated soil: a lysimeter field trial.
Hale, Sarah E; Elmquist, Marie; Brändli, Rahel; Hartnik, Thomas; Jakob, Lena; Henriksen, Thomas; Werner, David; Cornelissen, Gerard
2012-04-01
Activated carbon (AC) amendment is an innovative method for the in situ remediation of contaminated soils. A field-scale AC amendment of either 2% powder or granular AC (PAC and GAC) to a PAH contaminated soil was carried out in Norway. The PAH concentration in drainage water from the field plot was measured with a direct solvent extraction and by deploying polyoxymethylene (POM) passive samplers. In addition, POM samplers were dug directly in the AC amended and unamended soil in order to monitor the reduction in free aqueous PAH concentrations in the soil pore water. The total PAH concentration in the drainage water, measured by direct solvent extraction of the water, was reduced by 14% for the PAC amendment and by 59% for GAC, 12 months after amendment. Measurements carried out with POM showed a reduction of 93% for PAC and 56% for GAC. The free aqueous PAH concentration in soil pore water was reduced 93% and 76%, 17 and 28 months after PAC amendment, compared to 84% and 69% for GAC. PAC, in contrast to GAC, was more effective for reducing freely dissolved concentrations than total dissolved ones. This could tentatively be explained by leaching of microscopic AC particles from PAC. Secondary chemical effects of the AC amendment were monitored by considering concentration changes in dissolved organic carbon (DOC) and nutrients. DOC was bound by AC, while the concentrations of nutrients (NO(3), NO(2), NH(4), PO(4), P-total, K, Ca and Mg) were variable and likely affected by external environmental factors. Copyright © 2012 Elsevier Ltd. All rights reserved.
-
Zhang, Qian-qian; Wang, Fei; Liu, Tao; Chu, Gui-xin
2015-09-01
Brackish water irrigation utilization is an important way to alleviate water resource shortage in arid region. A field-plot experiment was set up to study the impact of the salinity level (0.31, 3.0 or 5.0 g · L(-1) NaCl) of irrigated water on activities of soil catalase, invertase, β-glucosidase, cellulase and polyphenoloxidase in drip irrigation condition, and the responses of soil CO2 flux and organic matter decomposition were also determined by soil carbon dioxide flux instrument (LI-8100) and nylon net bag method. The results showed that in contrast with fresh water irrigation treatment (CK), the activities of invertase, β-glucosidase and cellulase in the brackish water (3.0 g · L(-1)) irrigation treatment declined by 31.7%-32.4%, 29.7%-31.6%, 20.8%-24.3%, respectively, while soil polyphenoloxidase activity was obviously enhanced with increasing the salinity level of irrigated water. Compared to CK, polyphenoloxidase activity increased by 2.4% and 20.5%, respectively, in the brackish water and saline water irrigation treatments. Both soil microbial biomass carbon and microbial quotient decreased with increasing the salinity level, whereas, microbial metabolic quotient showed an increasing tendency with increasing the salinity level. Soil CO2 fluxes in the different treatments were in the order of CK (0.31 g · L(-1)) > brackish water irrigation (3.0 g · L(-1)) ≥ saline water irrigation (5.0 g · L(-1)). Moreover, CO2 flux from plastic film mulched soil was always much higher than that from no plastic film mulched soil, regardless the salinity of irrigated water. Compared with CK, soil CO2 fluxes in the saline water and brackish water treatments decreased by 29.8% and 28.2% respectively in the boll opening period. The decomposition of either cotton straw or alfalfa straw in the different treatments was in the sequence of CK (0.31 g · L(-1)) > brackish water irrigation (3.0 g · L(-1)) > saline water treatment (5.0 g · L(-1)). The organic matter
-
An overview of soil water sensors for salinity & irrigation management
Irrigation water management has to do with the appropriate application of water to soils, in terms of amounts, rates, and timing to satisfy crop water demands while protecting the soil and water resources from degradation. Accurate irrigation management is even more important in salt affected soils ...
-
Blevins, Dale W.
1989-01-01
Eighteen sources of drainage related to past coal-mining activity were identified in the Claybank Creek, Missouri, study area, and eight of them were considered large enough to have detectable effects on receiving streams. However, only three sources (two coal-waste sites and one spring draining an underground mine) significantly affected the chemistry of water in receiving streams. Coal wastes in the Claybank Creek basin contributed large quantities of acid drainage to receiving streams during storm runoff. The pH of coal-waste runoff ranged from 2.1 to 2.8. At these small pH values, concentrations of some dissolved metals and dissolved sulfate were a few to several hundred times larger than Federal and State water-quality standards established for these constituents. Effects of acid storm runoff were detected near the mouth of North Fork Claybank Creek where the pH during a small storm was 3.9. Coal wastes in the streambeds and seepage from coal wastes also had significant effects on receiving streams during base flows. The receiving waters had pH values between 2.8 and 3.5, and concentrations of some dissolved metals and dissolved sulfate were a few to several hundred times larger than Federal and State water-quality standards. Most underground mines in the North Fork Claybank Creek basin seem to be hydraulically connected, and about 80 percent of their discharge surfaced at one site. Drainage from the underground mines contributed most of the dissolved constituents in North Fork Claybank Creek during dry weather. Underground-mine water always had a pH near 5.9 and was well-buffered. It had a dissolved-sulfate concentration of about 2,400 milligrams per liter, dissolved-manganese concentrations ranging from 4.0 to 5.3 milligrams per liter, and large concentrations of ferrous iron. Iron was in the ferrous state because of reducing conditions in the mines. When underground-mine drainage reached the ground surface, the ferrous iron was oxidized and precipitated to
-
UNSAT-H Version 3.0: Unsaturated Soil Water and Heat Flow Model Theory, User Manual, and Examples
International Nuclear Information System (INIS)
Fayer, M.J.
2000-01-01
The UNSAT-H model was developed at Pacific Northwest National Laboratory (PNNL) to assess the water dynamics of arid sites and, in particular, estimate recharge fluxes for scenarios pertinent to waste disposal facilities. During the last 4 years, the UNSAT-H model received support from the Immobilized Waste Program (IWP) of the Hanford Site's River Protection Project. This program is designing and assessing the performance of on-site disposal facilities to receive radioactive wastes that are currently stored in single- and double-shell tanks at the Hanford Site (LMHC 1999). The IWP is interested in estimates of recharge rates for current conditions and long-term scenarios involving the vadose zone disposal of tank wastes. Simulation modeling with UNSAT-H is one of the methods being used to provide those estimates (e.g., Rockhold et al. 1995; Fayer et al. 1999). To achieve the above goals for assessing water dynamics and estimating recharge rates, the UNSAT-H model addresses soil water infiltration, redistribution, evaporation, plant transpiration, deep drainage, and soil heat flow as one-dimensional processes. The UNSAT-H model simulates liquid water flow using Richards' equation (Richards 1931), water vapor diffusion using Fick's law, and sensible heat flow using the Fourier equation. This report documents UNSAT-H .Version 3.0. The report includes the bases for the conceptual model and its numerical implementation, benchmark test cases, example simulations involving layered soils and plants, and the code manual. Version 3.0 is an, enhanced-capability update of UNSAT-H Version 2.0 (Fayer and Jones 1990). New features include hysteresis, an iterative solution of head and temperature, an energy balance check, the modified Picard solution technique, additional hydraulic functions, multiple-year simulation capability, and general enhancements
-
Raddadi, Noura
2018-05-31
Water stress is a critical issue for plant growth in arid sandy soils. Here, we aimed to select bacteria producing polyextremotolerant surface-active compounds capable of improving water retention and humidity uptake in sandy soils.From Tunisian desert and saline systems, we selected eleven isolates able to highly emulsify different organic solvents. The bioemulsifying activities were stable with 30% NaCl, at 4 and 120 °C and in a pH range 4-12. Applications to a sandy soil of the partially purified surface-active compounds improved soil water retention up to 314.3% compared to untreated soil. Similarly, after 36 h of incubation, the humidity uptake rate of treated sandy soil was up to 607.7% higher than untreated controls.Overall, results revealed that polyextremotolerant bioemulsifiers of bacteria from arid and desert soils represent potential sources to develop new natural soil-wetting agents for improving water retention in arid soils.
-
Raddadi, Noura; Giacomucci, Lucia; Marasco, Ramona; Daffonchio, Daniele; Cherif, Ameur; Fava, Fabio
2018-01-01
Water stress is a critical issue for plant growth in arid sandy soils. Here, we aimed to select bacteria producing polyextremotolerant surface-active compounds capable of improving water retention and humidity uptake in sandy soils.From Tunisian desert and saline systems, we selected eleven isolates able to highly emulsify different organic solvents. The bioemulsifying activities were stable with 30% NaCl, at 4 and 120 °C and in a pH range 4-12. Applications to a sandy soil of the partially purified surface-active compounds improved soil water retention up to 314.3% compared to untreated soil. Similarly, after 36 h of incubation, the humidity uptake rate of treated sandy soil was up to 607.7% higher than untreated controls.Overall, results revealed that polyextremotolerant bioemulsifiers of bacteria from arid and desert soils represent potential sources to develop new natural soil-wetting agents for improving water retention in arid soils.
-
Raddadi, Noura; Giacomucci, Lucia; Marasco, Ramona; Daffonchio, Daniele; Cherif, Ameur; Fava, Fabio
2018-05-31
Water stress is a critical issue for plant growth in arid sandy soils. Here, we aimed to select bacteria producing polyextremotolerant surface-active compounds capable of improving water retention and humidity uptake in sandy soils. From Tunisian desert and saline systems, we selected eleven isolates able to highly emulsify different organic solvents. The bioemulsifying activities were stable with 30% NaCl, at 4 and 120 °C and in a pH range 4-12. Applications to a sandy soil of the partially purified surface-active compounds improved soil water retention up to 314.3% compared to untreated soil. Similarly, after 36 h of incubation, the humidity uptake rate of treated sandy soil was up to 607.7% higher than untreated controls. Overall, results revealed that polyextremotolerant bioemulsifiers of bacteria from arid and desert soils represent potential sources to develop new natural soil-wetting agents for improving water retention in arid soils.
-
Complex linkage between soil, soil water, atmosphere and Eucalyptus Plantations
Shukla, C.; Tiwari, K. N.
2017-12-01
Eucalyptus is most widely planted genus grown in waste land of eastern region of India to meet the pulp industry requirements. Sustainability of these plantations is of concern because in spite of higher demand water and nutrients of plantations, they are mostly planted on low-fertility soils. This study has been conducted to quantify effect of 25 years old, a fully established eucalyptus plantations on i.) Alteration in physico-chemical and hydrological properties of soil of eucalyptus plantation in comparison to soil of natural grassland and ii.) Spatio-temporal variation in soil moisture under eucalyptus plantations. Soil physico-chemical properties of two adjacent plots covered with eucatuptus and natural grasses were analyzed for three consecutive depths (i.e. 0-30 cm, 30-60 cm and 60-90 cm) with five replications in each plot. Soil infiltration rate and saturated hydraulic conductivity (Ks) were measured in-situ to incorporate the influence of macro porosity caused due to roots of plantations. Daily soil moisture at an interval of 10 cm upto 160 cm depth with 3 replications and Leaf Area Index (LAI) at an interval of 15 days with 5 replications were recorded over the year. Significant variations found at level of 0.05 between soil properties of eucalyptus and natural grass land confirm the effect of plantations on soil properties. Comparative results of soil properties show significant alteration in soil texture such as percent of sand, organic matter and Ks found more by 20%, 9% and 22% respectively in eucalyptus plot as compare to natural grass land. Available soil moisture (ASM) was found constantly minimum in top soil excluding rainy season indicate upward movement of water and nutrients during dry season. Seasonal variation in temperature (T), relative humidity (RH) and leaf area index (LAI) influenced the soil moisture extraction phenomenon. This study clearly stated the impact of long term establishment of eucalyptus plantations make considerable
-
Muamar Rifa'i, Alfian; Setiawan, Bambang; Djarwanti, Noegroho
2017-12-01
The expansive soil is soil that has a potential for swelling-shrinking due to changes in water content. Such behavior can exert enough force on building above to cause damage. The use of columns filled with additives such as Calcium Carbide is done to reduce the negative impact of expansive soil behavior. This study aims to determine the effect of carbide columns on expansive soil. Observations were made on swelling and spreading of carbides in the soil. 7 Carbide columns with 5 cm diameter and 20 cm height were installed into the soil with an inter-column spacing of 8.75 cm. Wetting is done through a pipe at the center of the carbide column for 20 days. Observations were conducted on expansive soil without carbide columns and expansive soil with carbide columns. The results showed that the addition of carbide column could reduce the percentage of swelling by 4.42%. Wetting through the center of the carbide column can help spread the carbide into the soil. The use of carbide columns can also decrease the rate of soil expansivity. After the addition of carbide column, the plasticity index value decreased from 71.76% to 4.3% and the shrinkage index decreased from 95.72% to 9.2%.
-
Performance of chromatographic systems to model soil-water sorption.
Hidalgo-Rodríguez, Marta; Fuguet, Elisabet; Ràfols, Clara; Rosés, Martí
2012-08-24
A systematic approach for evaluating the goodness of chromatographic systems to model the sorption of neutral organic compounds by soil from water is presented in this work. It is based on the examination of the three sources of error that determine the overall variance obtained when soil-water partition coefficients are correlated against chromatographic retention factors: the variance of the soil-water sorption data, the variance of the chromatographic data, and the variance attributed to the dissimilarity between the two systems. These contributions of variance are easily predicted through the characterization of the systems by the solvation parameter model. According to this method, several chromatographic systems besides the reference octanol-water partition system have been selected to test their performance in the emulation of soil-water sorption. The results from the experimental correlations agree with the predicted variances. The high-performance liquid chromatography system based on an immobilized artificial membrane and the micellar electrokinetic chromatography systems of sodium dodecylsulfate and sodium taurocholate provide the most precise correlation models. They have shown to predict well soil-water sorption coefficients of several tested herbicides. Octanol-water partitions and high-performance liquid chromatography measurements using C18 columns are less suited for the estimation of soil-water partition coefficients. Copyright © 2012 Elsevier B.V. All rights reserved.
-
[Effects of land use changes on soil water conservation in Hainan Island, China].
Wen, Zhi; Zhao, He; Liu, Lei; OuYang, Zhi Yun; Zheng, Hua; Mi, Hong Xu; Li, Yan Min
2017-12-01
In tropical areas, a large number of natural forests have been transformed into other plantations, which affected the water conservation function of terrestrial ecosystems. In order to clari-fy the effects of land use changes on soil water conservation function, we selected four typical land use types in the central mountainous region of Hainan Island, i.e., natural forests with stand age greater than 100 years (VF), secondary forests with stand age of 10 years (SF), areca plantations with stand age of 12 years (AF) and rubber plantations with stand age of 35 years (RF). The effects of land use change on soil water holding capacity and water conservation (presented by soil water index, SWI) were assessed. The results showed that, compared with VF, the soil water holding capacity index of other land types decreased in the top soil layer (0-10 cm). AF had the lowest soil water holding capacity in all soil layers. Soil water content and maximum water holding capacity were significantly related to canopy density, soil organic matter and soil bulk density, which indicated that canopy density, soil organic matter and compactness were important factors influencing soil water holding capacity. Compared to VF, soil water conservation of SF, AF and RF were reduced by 27.7%, 54.3% and 11.5%, respectively. The change of soil water conservation was inconsistent in different soil layers. Vegetation canopy density, soil organic matter and soil bulk density explained 83.3% of the variance of soil water conservation. It was suggested that land use conversion had significantly altered soil water holding capacity and water conservation function. RF could keep the soil water better than AF in the research area. Increasing soil organic matter and reducing soil compaction would be helpful to improve soil water holding capacity and water conservation function in land management.
-
Soil volumetric water content measurements using TDR technique
Directory of Open Access Journals (Sweden)
S. Vincenzi
1996-06-01
Full Text Available A physical model to measure some hydrological and thermal parameters in soils will to be set up. The vertical profiles of: volumetric water content, matric potential and temperature will be monitored in different soils. The volumetric soil water content is measured by means of the Time Domain Reflectometry (TDR technique. The result of a test to determine experimentally the reproducibility of the volumetric water content measurements is reported together with the methodology and the results of the analysis of the TDR wave forms. The analysis is based on the calculation of the travel time of the TDR signal in the wave guide embedded in the soil.
-
Harmonisation of the soil map of Africa at the continental scale
DEFF Research Database (Denmark)
Dewitte, Olivier; Jones, Arwyn; Spaargaren, Otto
2013-01-01
In the context of major global environmental challenges such as food security, climate change, fresh water scarcity and biodiversity loss, the protection and the sustainable management of soil resources in Africa are of paramount importance. To raise the awareness of the general public...... with no information, soil patterns, river and drainage networks, and dynamic features such as sand dunes, water bodies and coastlines. In comparison to the initial map derived from HWSD, the new map represents a correction of 13% of the soil data for the continent. The map is available for downloading. (C) 2013......, stakeholders, policy makers and the science community to the importance of soil in Africa, the Joint Research Centre of the European Commission has produced the Soil Atlas of Africa. To that end, a new harmonised soil map at the continental scale has been produced. The steps of the construction of the new area...
-
Soil ecology and ecosystem services of dairy and semi-natural grasslands on peat
Deru, Joachim G.C.; Bloem, Jaap; Goede, de Ron; Keidel, Harm; Kloen, Henk; Rutgers, Michiel; Akker, van den Jan; Brussaard, Lijbert; Eekeren, van Nick
2018-01-01
Peat wetlands are of major importance for ecosystem services such as carbon storage, water regulation and maintenance of biodiversity. However, peat drainage for farming leads to CO2 emission, soil subsidence and biodiversity losses. In the peat areas in the Netherlands, solutions are sought in
-
Energy Technology Data Exchange (ETDEWEB)
1991-10-25
This paper is a research report concerning the water and soil maintenance and the technical advance of disaster preventing function of forests. As for the water maintenance control to clarify the water maintenance function of forests and to advance retaining and increasing technique, amount of precipitation on valleys and ridges, amount of evapotranspiration in a summer rainy season, underground water in woodlands and water circulating characteristics in montane zones were studied. The amount of evapotranspiration and the crown interception in water drainage area in Tsukuba forest of Japan were surveyed. A formula to estimate the flow rate was derived by surveying the change of flow rate through cutting forests at a riverhead in a heavy snow area and by analyzing data at 29 drainage areas. As for the clarification of the occurring mechanism of a soil disaster and the development of forest conservation technique, a simulation of boulder flow flood at a practical damaged district was carried out and it could be estimated by a tank model that the water level at a collector well fallen down in a landslide area. As for the survey of disaster preventing function of forests and the improvement of disaster preventing means, if damaged trees in frozen damage and discoloration area are pruned, the discoloration becomes very slight. The arborescent trees were selected from the standing tree density or forest physiognomy for the frequent land of full-depth avalanche. Japanese beeches, maples, oaks and Magnolia hypoleuca are suitable for a heavy snowarea. 1 tab.
-
[Foliar water use efficiency of Platycladus orientalis sapling under different soil water contents].
Zhang, Yong E; Yu, Xin Xiao; Chen, Li Hua; Jia, Guo Dong; Zhao, Na; Li, Han Zhi; Chang, Xiao Min
2017-07-18
The determination of plant foliar water use efficiency will be of great value to improve our understanding about mechanism of plant water consumption and provide important basis of regional forest ecosystem management and maintenance, thus, laboratory controlled experiments were carried out to obtain Platycladus orientalis sapling foliar water use efficiency under five different soil water contents, including instantaneous water use efficiency (WUE gs ) derived from gas exchange and short-term water use efficiency (WUE cp ) caculated using carbon isotope model. The results showed that, controlled by stomatal conductance (g s ), foliar net photosynthesis rate (P n ) and transpiration rate (T r ) increased as soil water content increased, which both reached maximum va-lues at soil water content of 70%-80% field capacity (FC), while WUE gs reached a maximum of 7.26 mmol·m -2 ·s -1 at the lowest soil water content (35%-45% FC). Both δ 13 C of water-soluble leaf and twig phloem material achieved maximum values at the lowest soil water content (35%-45% FC). Besides, δ 13 C values of leaf water-soluble compounds were significantly greater than that of phloem exudates, indicating that there was depletion in 13 C in twig phloem compared with leaf water-soluble compounds and no obvious fractionation in the process of water-soluble material transportation from leaf to twig. Foliar WUE cp also reached a maximum of 7.26 mmol·m -2 ·s -1 at the lowest soil water content (35%-45% FC). There was some difference between foliar WUE gs and WUE cp under the same condition, and the average difference was 0.52 mmol·m -2 ·s -1 . The WUE gs had great space-time variability, by contrast, WUE cp was more representative. It was concluded that P. orientalis sapling adapted to drought condition by increasing water use efficiency and decreasing physiological activity.
-
Modeling Soil Water Retention Curves in the Dry Range Using the Hygroscopic Water Content
DEFF Research Database (Denmark)
Chen, Chong; Hu, Kelin; Arthur, Emmanuel
2014-01-01
Accurate information on the dry end (matric potential less than −1500 kPa) of soil water retention curves (SWRCs) is crucial for studying water vapor transport and evaporation in soils. The objectives of this study were to assess the potential of the Oswin model for describing the water adsorption...... curves of soils and to predict SWRCs at the dry end using the hygroscopic water content at a relative humidity of 50% (θRH50). The Oswin model yielded satisfactory fits to dry-end SWRCs for soils dominated by both 2:1 and 1:1 clay minerals. Compared with the Oswin model, the Campbell and Shiozawa model...... for soils dominated by 2:1 and 1:1 clays, respectively. Comparison of the Oswin model combined with the Kelvin equation, with water potential estimated from θRH50 (Oswin-KRH50), CS model combined with the Arthur equation (CS-A), and CS-K model, with water potential obtained from θRH50 (CS-KRH50) indicated...
-
Gravity Drainage of Activated Sludge on Reed Beds
DEFF Research Database (Denmark)
Christensen, Morten Lykkegaard; Dominiak, Dominik Marek; Keiding, Kristian
and operation of reed beds and the efficiencies are often lower than predicted. One reason is that the sludge quality varies from plant to plant and even within plants from time to time. No good method exists for measuring the sludge quality with respect to drainage characteristics. A new experimental method...... has therefore been developed to measure relevant quality parameters: specific cake resistance, settling velocity and cake compressibility. It has been found that activated sludge form highly compressible cake even at the low compressive pressures obtained during drainage. Numerical simulation shows......Activated sludge is a by-product from waste water treatment plants, and the water content in the sludge is high (> 90%). Among several methods to remove the water, sludge drying reed beds are often used to dewater the sludge by drainage. There is, however, no well-defined criterion for design...
-
International Nuclear Information System (INIS)
El-Sadek, A.; Feyen, J.; Ragab, R.
2002-01-01
'Full text:' Denitrification is the process by which nitrate-nitrogen is converted to nitrogen gas by soil microorganisms when soil oxygen is low or absent. The process of denitrification is important in preventing high agriculture-source nitrate loads from entering and polluting rivers. The aim of the research was to examine if the NO3-N concentration in drain water of agricultural fields can be kept below the EU limit of 11.3 mg l -1 by controlling the denitrification process through management of the water table level. As such the research focused on the determination of the exact denitrification amount to achieve both, limitation of the NO3-N leaching and optimisation of the nitrogen-nitrate uptake by the crop. The method used in this study is based on the nitrogen version of DRAINMOD model. This model was used to simulate the performance of the drainage system using two drainage strategies (conventional and controlled) at the Hooibeekhoeve experiment, situated in the sandy region of the Kempen (Belgium), and this for a 14-year (1985-1998) period. In the analysis a continuous cropping with maize was assumed. Daily NO3-N losses were predicted for a range of drain spacings. The study illustrated that the denitrification process has a very strong impact on the amount of nitrate that can be leached to ground and surface waters. The results have also shown that if the water table elevation is properly controlled, one should be able to strike the delicate balance between our need for maximum yield production and a minimum hazard to our environment. (author)
-
Percolation behavior of tritiated water into a soil packed bed
Energy Technology Data Exchange (ETDEWEB)
Honda, T.; Katayama, K.; Uehara, K.; Fukada, S. [Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, Kasuga, Fukuoka (Japan); Takeishi, T. [Faculty of Engineering, Kyushu University, Motooka Nishi-ku, Fukuoka (Japan)
2015-03-15
A large amount of cooling water is used in a D-T fusion reactor. The cooling water will contain tritium with high concentration because tritium can permeate metal walls at high temperature easily. A development of tritium handling technology for confining tritiated water in the fusion facility is an important issue. In addition, it is also important to understand tritium behavior in environment assuming severe accidents. In this study, percolation experiments of tritiated water in soil packed bed were carried out and tritium behavior in soil was discussed. Six soil samples were collected in Hakozaki campus of Kyushu University. These particle densities were of the same degree as that of general soils and moisture contents were related to BET surface area. For two soil samples used in the percolation experiment of tritiated water, saturated hydraulic conductivity agreed well with the estimating value by Creager. Tritium retention ratio in the soil packed bed was larger than water retention. This is considered to be due to an effect of tritium sorption on the surface of soil particles. The isotope exchange capacity estimated by assuming that H/T ratio of supplied tritiated water and H/T ratio of surface water of soil particle was equal was comparable to that on cement paste and mortar which were obtained by exposure of tritiated water vapor. (authors)
-
Percolation behavior of tritiated water into a soil packed bed
International Nuclear Information System (INIS)
Honda, T.; Katayama, K.; Uehara, K.; Fukada, S.; Takeishi, T.
2015-01-01
A large amount of cooling water is used in a D-T fusion reactor. The cooling water will contain tritium with high concentration because tritium can permeate metal walls at high temperature easily. A development of tritium handling technology for confining tritiated water in the fusion facility is an important issue. In addition, it is also important to understand tritium behavior in environment assuming severe accidents. In this study, percolation experiments of tritiated water in soil packed bed were carried out and tritium behavior in soil was discussed. Six soil samples were collected in Hakozaki campus of Kyushu University. These particle densities were of the same degree as that of general soils and moisture contents were related to BET surface area. For two soil samples used in the percolation experiment of tritiated water, saturated hydraulic conductivity agreed well with the estimating value by Creager. Tritium retention ratio in the soil packed bed was larger than water retention. This is considered to be due to an effect of tritium sorption on the surface of soil particles. The isotope exchange capacity estimated by assuming that H/T ratio of supplied tritiated water and H/T ratio of surface water of soil particle was equal was comparable to that on cement paste and mortar which were obtained by exposure of tritiated water vapor. (authors)
-
van der Ploeg, Martine; de Rooij, Gerrit
2014-05-01
Periods of soil water deficit often occur within a plant's life cycle, even in temperate deciduous and rain forests (Wilson et al. 2001, Grace 1999). Various experiments have shown that roots are able to sense the distribution of water in the soil, and produce signals that trigger changes in leaf expansion rate and stomatal conductance (Blackman and Davies 1985, Gollan et al. 1986, Gowing et al. 1990 Davies and Zhang 1991, Mansfield and De Silva 1994, Sadras and Milroy 1996). Partitioning of water and air in the soil, solute distribution in soil water, water flow through the soil, and water availability for plants can be determined according to the distribution of the soil water potential (e.g. Schröder et al. 2013, Kool et al. 2014). Understanding plant water uptake under dry conditions has been compromised by hydrological instrumentation with low accuracy in dry soils due to signal attenuation, or a compromised measurement range (Whalley et al. 2013). Development of polymer tensiometers makes it possible to study the soil water potential over a range meaningful for studying plant responses to water stress (Bakker et al. 2007, Van der Ploeg et al. 2008, 2010). Polymer tensiometer data obtained from a lysimeter experiment (Van der Ploeg et al. 2008) were used to analyse day-night fluctuations of soil moisture in the vicinity of maize roots. To do so, three polymer tensiometers placed in the middle of the lysimeter from a control, dry and very dry treatment (one lysimeter per treatment) were used to calculate water content changes over 12 hours. These 12 hours corresponded with the operation of the growing light. Soil water potential measurements in the hour before the growing light was turned on or off were averaged. The averaged value was used as input for the van Genuchten (1980) model. Parameters for the model were obtained from laboratory determination of water retention, with a separate model parameterization for each lysimeter setup. Results show daily
-
Relationship between root water uptake and soil respiration: A modeling perspective
Teodosio, Bertrand; Pauwels, Valentijn R. N.; Loheide, Steven P.; Daly, Edoardo
2017-08-01
Soil moisture affects and is affected by root water uptake and at the same time drives soil CO2 dynamics. Selecting root water uptake formulations in models is important since this affects the estimation of actual transpiration and soil CO2 efflux. This study aims to compare different models combining the Richards equation for soil water flow to equations describing heat transfer and air-phase CO2 production and flow. A root water uptake model (RWC), accounting only for root water compensation by rescaling water uptake rates across the vertical profile, was compared to a model (XWP) estimating water uptake as a function of the difference between soil and root xylem water potential; the latter model can account for both compensation (XWPRWC) and hydraulic redistribution (XWPHR). Models were compared in a scenario with a shallow water table, where the formulation of root water uptake plays an important role in modeling daily patterns and magnitudes of transpiration rates and CO2 efflux. Model simulations for this scenario indicated up to 20% difference in the estimated water that transpired over 50 days and up to 14% difference in carbon emitted from the soil. The models showed reduction of transpiration rates associated with water stress affecting soil CO2 efflux, with magnitudes of soil CO2 efflux being larger for the XWPHR model in wet conditions and for the RWC model as the soil dried down. The study shows the importance of choosing root water uptake models not only for estimating transpiration but also for other processes controlled by soil water content.
-
Water dynamics in a bean crop (Phaseolus vulgaris)
International Nuclear Information System (INIS)
Calvache, Marcelo; Garcia, Carlos.
1987-01-01
The dynamics of water was studied at 'La Tola', Experimental Teaching Center of the Central University of Ecuador, in a Sandy-Ioan, typic Haplustoll soil, in wich beans were growing. All the components of the crop water balance were determined. Real evapotranspiration was in direct relation to the growth of the crop, reaching its maximum value of 4.9 mm day-1, at pod setting, then decreasing slowly until maturation of the kernels. Up to 1 meter depth, water loss by drainage depended on rainfall, reaching up to 24% of the total water loss: the soil layer supplying most of the water for the use of the crop was between 0-40 cm, where the root activity was greatest
-
Effects of soil and water conservation practices on selected soil ...
African Journals Online (AJOL)
Although different types of soil and water conservation practices (SWCPs) were introduced, the sustainable use of these practices is far below expectations, and soil erosion continues to be a severe problem in Ethiopia. Therefore, this study was conducted at Debre Yakobe Micro-Watershed (DYMW), Northwest Ethiopia ...
-
Geohydrologic reconnaissance of drainage wells in Florida; an interim report
Kimrey, Joel O.; Fayard, Larry D.
1982-01-01
Drainage wells are used to inject surface waters directly into an aquifer, or shallow ground waters directly into a deeper aquifer, primarily by gravity. Such wells in Florida may be grouped into two broad types: (1) Surface-water injection wells, and (2) interaquifer connector wells. Surface-water injection wells are commonly used to supplement drainage for urban areas in karst terranes of central and north Florida. Data are available for 25 wells in the Ocala, Live Oak, and Orlando areas that allow comparison of the quality of water samples from these Floridan aquifer drainage wells with allowable contaminant levels. Comparison indicates that maximum contaminant levels for turbidity, color, and iron, manganese, and lead concentrations are equaled or exceeded in some drainage-well samples, and relatively high counts for coliform bacteria are present in most wells. Interaquifer connector wells are used in the phosphate mining areas of Polk and Hillsborough Counties, to drain mining operations and recharge the Floridan aquifer. Water-quality data available from 13 connector wells indicate that samples from most of these wells exceed standards values for iron concentration and turbidity. One well yielded a highly mineralized water, and samples from 6 of the other 12 wells exceed standards values for gross alpha concentrations. (USGS)
-
CO2 efflux from soils with seasonal water repellency
Urbanek, Emilia; Doerr, Stefan H.
2017-10-01
Soil carbon dioxide (CO2) emissions are strongly dependent on pore water distribution, which in turn can be modified by reduced wettability. Many soils around the world are affected by soil water repellency (SWR), which reduces infiltration and results in diverse moisture distribution. SWR is temporally variable and soils can change from wettable to water-repellent and vice versa throughout the year. Effects of SWR on soil carbon (C) dynamics, and specifically on CO2 efflux, have only been studied in a few laboratory experiments and hence remain poorly understood. Existing studies suggest soil respiration is reduced with increasing severity of SWR, but the responses of soil CO2 efflux to varying water distribution created by SWR are not yet known.Here we report on the first field-based study that tests whether SWR indeed reduces soil CO2 efflux, based on in situ measurements carried out over three consecutive years at a grassland and pine forest sites under the humid temperate climate of the UK.Soil CO2 efflux was indeed very low on occasions when soil exhibited consistently high SWR and low soil moisture following long dry spells. Low CO2 efflux was also observed when SWR was absent, in spring and late autumn when soil temperatures were low, but also in summer when SWR was reduced by frequent rainfall events. The highest CO2 efflux occurred not when soil was wettable, but when SWR, and thus soil moisture, was spatially patchy, a pattern observed for the majority of the measurement period. Patchiness of SWR is likely to have created zones with two different characteristics related to CO2 production and transport. Zones with wettable soil or low persistence of SWR with higher proportion of water-filled pores are expected to provide water with high nutrient concentration resulting in higher microbial activity and CO2 production. Soil zones with high SWR persistence, on the other hand, are dominated by air-filled pores with low microbial activity, but facilitating O2