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1

Spatiotemporal analysis of urban environment based on the vegetation-impervious surface-soil model  

Science.gov (United States)

This study explores a spatiotemporal comparative analysis of urban agglomeration, comparing the Greater Toronto and Hamilton Area (GTHA) of Canada and the city of Tianjin in China. The vegetation-impervious surface-soil (V-I-S) model is used to quantify the ecological composition of urban/peri-urban environments with multitemporal Landsat images (3 stages, 18 scenes) and LULC data from 1985 to 2005. The support vector machine algorithm and several knowledge-based methods are applied to get the V-I-S component fractions at high accuracies. The statistical results show that the urban expansion in the GTHA occurred mainly between 1985 and 1999, and only two districts revealed increasing trends for impervious surfaces for the period from 1999 to 2005. In contrast, Tianjin has been experiencing rapid urban sprawl at all stages and this has been accelerating since 1999. The urban growth patterns in the GTHA evolved from a monocentric and dispersed pattern to a polycentric and aggregated pattern, while in Tianjin it changed from monocentric to polycentric. Central Tianjin has become more centralized, while most other municipal areas have developed dispersed patterns. The GTHA also has a higher level of greenery and a more balanced ecological environment than Tianjin. These differences in the two areas may play an important role in urban planning and decision-making in developing countries.

Guo, Huadong; Huang, Qingni; Li, Xinwu; Sun, Zhongchang; Zhang, Ying

2014-01-01

2

Continental-scale Sensitivity of Water Yield to Changes in Impervious Cover  

Science.gov (United States)

Projected land conversion from native forest, grassland, and shrubland to urban impervious cover will alter watershed water balances by reducing groundwater recharge and evapotranspiration, increasing surface runoff, and potentially altering regional weather patterns. These hydrologic changes have important ecohydrological implications to local watersheds, including stream channel habitat degradation and the loss of aquatic biodiversity. Many observational studies have evaluated the impact of urbanization on water yield in small catchments downstream of specific urban areas. However it is often difficult to separate the impact of impervious cover from other impacts of urbanization such as leaking water infrastructure, irrigation runoff, water supply withdrawals, and effluent discharge. In addition, the impact of impervious cover has not been evaluated at scales large enough to assess spatial differences in water yield sensitivity to changes in impervious cover. The objective of this study was to assess the sensitivity of water yield to impervious cover across the conterminous U.S., and to identify locations where water yield will be most impacted by future urbanization. We used the Water Supply Stress Index (WaSSI) model to simulate monthly water yield as impacted by impervious cover for the approximately 82,000 12-digit HUC watersheds across the conterminous U.S. WaSSI computed infiltration, surface runoff, soil moisture, and baseflow processes explicitly for ten vegetative land cover classes and impervious cover in each watershed using the 2006 National Land Cover Dataset estimates of impervious cover. Our results indicate that impervious cover has increased total water yield in urban areas (relative to native vegetation), and that the increase was most significant during the growing season. The proportion of stream flow that occurred as baseflow decreased, even though total water yield increased as a result of impervious cover. Water yield was most sensitive to changes in impervious cover in areas where annual evapotranspiration is high relative to precipitation (e.g. the Southwestern States, Texas, and Florida). Water yield was less sensitive in areas with low evapotranspiration relative to precipitation (e.g. Pacific Northwest and Northeastern States). Additionally, water yield was most impacted when high evapotranspiration land cover types (e.g. forests) were converted to impervious cover than when lower evapotranspiration land cover types (e.g. grassland) were converted. Using projections of future impervious cover provided by the U.S. EPA Integrated Climate and Land Use Scenarios project, water yield in urban areas of the Southwest, Texas, and Florida will be the most impacted by 2050, in part because these areas are projected to have significant increases in impervious cover, but also because they are in areas where evapotranspiration is high relative to precipitation. Our study suggests that watershed management should consider the climate-driven sensitivity of water yield to increases in impervious cover and the type of land cover being converted in addition to the magnitude of projected increases in impervious cover when evaluating impacts of urbanization on water resources.

Caldwell, P.; Sun, G.; McNulty, S.; Cohen, E.; Moore Myers, J.

2012-12-01

3

Semi Impervious Subsurface Barrier for Water Conservation in Lateritic Formations  

Science.gov (United States)

The coastal districts of Karnataka in west coast of India experience acute shortage of drinking water during dry season in spite of heavy monsoon rains. Though sufficient recharge of ground water takes place, depletion of water table is very quick, once the rain recedes. It is mainly attributed to the presence of porous and highly permeable laterites and lateritic soils. The hydraulic conductivity of these soils varies in the range of 10-4 to 10-5 cm/s. The conventional water harvesting methods fail to solve the problem. It is necessary to explore innovative method to regulate the lateral subsurface flow and maintain a high water table over a prolonged period of time. The present work is an attempt to explore the possibility of using semi impervious Subsurface Barrier (SSB) to regulate and control the lateral flow of water in the unconfined aquifer in lateritic formations. Appropriate barrier material is arrived at using the locally available soil and the required properties are established. A SSB is built in a suitable location in an identified microwatershed using lateritic soil and the composite soil prepared by mixing requisite percentage of lateritic soil and clay. The hydraulic conductivity of these soils is maintained in the range of 10-6 to 10-7 cm/s so as to behave as semi impervious. The performance analysis is carried out by observing water levels in selected open observation wells before and after the construction of the barrier. The results have shown the successful performance of SSB in maintaining a high water table over a prolonged period of time during summer months, both in u/s and d/s of the barrier.

Udayakumar, G.; Mayya, S. G.

2014-09-01

4

Estimating and Mapping Urban Impervious Surfaces: Reflection on Spectral, Spatial, and Temporal Resolutions  

Science.gov (United States)

Impervious surface is a key indicator of urban environmental quality and urbanization degree. Therefore, estimation and mapping of impervious surfaces in urban areas has attracted more and more attention recently by using remote sensing digital images. In this paper, satellite images with various spectral, spatial, and temporal resolutions are employed to examine the effects of these remote sensing data characteristics on mapping accuracy of urban impervious surfaces. The study area was the city proper of Indianapolis (Marion County), Indiana, United States. Linear spectral mixture analysis was applied to generate high albedo, low albedo, vegetation, and soil fraction images (endmembers) from the satellite images, and impervious surfaces were then estimated by adding high albedo and low albedo fraction images. A comparison of EO-1 ALI (multispectral) and Hyperion (hyperspectral) images indicates that the Hyperion image was more effective in discerning low albedo surface materials, especially the spectral bands in the mid-infrared region. Linear spectral mixing modeling was found more useful for medium spatial resolution images, such as Landsat TM/ETM+ and ASTER images, due to the existence of a large amount of mixed pixels in the urban areas. The model, however, may not be suitable for high spatial resolution images, such as IKONOS images, because of less influence from the mixing pixel. The shadow problem in the high spatial resolution images, caused by tall buildings and large tree crowns, is a challenge in impervious surface extraction. Alternative image processing algorithms such as decision tree classifier may be more appropriate to achieve high mapping accuracy. For mid-latitude cities, seasonal vegetation phenology has a significant effect on the spectral response of terrestrial features, and therefore, image analysis must take into account of this environmental characteristic. Three ASTER images, acquired on April 5, 2004, June 16, 2001, and October 3, 2000, respectively, were used to test the seasonal sensitivity of impervious surface estimation. Our results indicated that the summer (June) image was better than the spring (April) and the fall (October) ones. The summer image was most appropriate because there was full growth of vegetation, and mapping of impervious surfaces was more effective with contrasting spectral response from green vegetation. The mixing space, based on the four endmembers was perfectly three-dimensional. In contrast, there was significant amount of bare soils/grounds and non-photosynthesis vegetation in the spring and fall images. Plant phenology caused changes in the variance partitioning and impacted the mixing space characterization, leading to the difficulty in the estimation of impervious surfaces.

Weng, Q.

2007-12-01

5

Koeberg harbour features an impervious breakwater  

International Nuclear Information System (INIS)

Construction of the Koeberg Power Station harbour (more strictly, the cooling water intake basin) is well advanced and the contractors expect to complete work before the end of 1979, six months ahead of schedule. The project manager, Mr W. Robinson of Underwater Construction and Salvage Co, describes the progress made on the contract in this article. An unusual feature of the harbour is that it will incorporate an impervious breakwater, reportedly South Africa's first

6

Prior-knowledge-based spectral mixture analysis for impervious surface mapping  

Energy Technology Data Exchange (ETDEWEB)

In this study, we developed a prior-knowledge-based spectral mixture analysis (PKSMA) to map impervious surfaces by using endmembers derived separately for high- and low-density urban regions. First, an urban area was categorized into high- and low-density urban areas, using a multi-step classification method. Next, in high-density urban areas that were assumed to have only vegetation and impervious surfaces (ISs), the Vegetation-Impervious model (V-I) was used in a spectral mixture analysis (SMA) with three endmembers: vegetation, high albedo, and low albedo. In low-density urban areas, the Vegetation-Impervious-Soil model (V-I-S) was used in an SMA analysis with four endmembers: high albedo, low albedo, soil, and vegetation. The fraction of IS with high and low albedo in each pixel was combined to produce the final IS map. The root mean-square error (RMSE) of the IS map produced using PKSMA was about 11.0%, compared to 14.52% using four-endmember SMA. Particularly in high-density urban areas, PKSMA (RMSE = 6.47%) showed better performance than four-endmember (15.91%). The results indicate that PKSMA can improve IS mapping compared to traditional SMA by using appropriately selected endmembers and is particularly strong in high-density urban areas.

Zhang, Jinshui; He, Chunyang; Zhou, Yuyu; Zhu, Shuang; Shuai, Guanyuan

2014-01-03

7

USEPA EPIC IMPERVIOUS SURFACE RESEARCH IN THE MID-ATLANTIC  

Science.gov (United States)

Anthropogenic impervious surfaces have an important relationship with non-point source pollution (NPS) in urban watersheds. These human-created surfaces include such features as roads, parking lots, rooftops, sidewalks, and driveways. The amount of impervious surface area in a ...

8

Generating Ground Reference Data for a Global Impervious Surface Survey  

Science.gov (United States)

We are developing an approach for generating ground reference data in support of a project to produce a 30m impervious cover data set of the entire Earth for the years 2000 and 2010 based on the Landsat Global Land Survey (GLS) data set. Since sufficient ground reference data for training and validation is not available from ground surveys, we are developing an interactive tool, called HSegLearn, to facilitate the photo-interpretation of 1 to 2 m spatial resolution imagery data, which we will use to generate the needed ground reference data at 30m. Through the submission of selected region objects and positive or negative examples of impervious surfaces, HSegLearn enables an analyst to automatically select groups of spectrally similar objects from a hierarchical set of image segmentations produced by the HSeg image segmentation program at an appropriate level of segmentation detail, and label these region objects as either impervious or nonimpervious.

Tilton, James C.; De Colstoun, Eric Brown; Wolfe, Robert E.; Tan, Bin; Huang, Chengquan

2012-01-01

9

Global Land Survey Impervious Mapping Project Web Site  

Science.gov (United States)

The Global Land Survey Impervious Mapping Project (GLS-IMP) aims to produce the first global maps of impervious cover at the 30m spatial resolution of Landsat. The project uses Global Land Survey (GLS) Landsat data as its base but incorporates training data generated from very high resolution commercial satellite data and using a Hierarchical segmentation program called Hseg. The web site contains general project information, a high level description of the science, examples of input and output data, as well as links to other relevant projects.

DeColstoun, Eric Brown; Phillips, Jacqueline

2014-01-01

10

CONTROLLING STORM WATER RUNOFF WITH TRADABLE CREDITS FOR IMPERVIOUS SURFACES  

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Storm water flow off impervious surface in a watershed can lead to stream degradation, habitat alteration, low base flows and toxic leading. We show that a properly designed tradable runoff credit (TRC) system creates economic incentives for landowners to employ best management p...

11

to characterize the impervious water storage with an urban surface-flux parameterization TERRA-MLU: evaluation and calibration for Toulouse city  

Science.gov (United States)

Evaporation from the urban impervious surface could have a considerable impact on the surface energy and moisture balance on rainy days. In particular, the ever increasing urbanization could alter the interaction between evaporation from the surface and precipitation within the urban climate (change) in the future. However, uncertainty exists within the determination of water storage parameters for the impervious surface, and hydrological parameters of the soil for the natural fraction in urban environments. In order to investigate the water balance over urban areas in more detail, TERRA-MLU, a new urban surface-flux parameterization, is applied over Toulouse city centre during the CAPITOUL campaign during 2004. The new urban parameterization covers a direct implementation of urban characteristics in TERRA_ML, Soil-Vegetation-Atmosphere Transfer model of COSMO. Besides anthropogenic heat, specific dynamic, radiative and thermal parameters including roughness length, heat capacity, conductivity, albedo and emissivity are assigned for the urban land-cover. A bluff-roughness thermal roughness length parametrization is used. New surface-layer transfer coefficients are adopted which can deal with very small thermal roughness lengths typical for urban surfaces. An new impervious water storage parameterization is introduced as well. TERRA-MLU is evaluated 'offline' for Marseille, Toulouse, Basel and Vancouver. Sensitivity analysis at the Toulouse site demonstrates that the maximum impervious water storage needs to be equal or less than 1kg/m2 if one only considers evaporation at a potential rate from the impervious surface. Furthermore, results are improved by implementing a storage form parameter that accounts for the reduction of evaporative surface fraction in case of small water content on the impervious surface. An offline sensitivity analysis is performed to estimate the maximum water storage and the storage form parameter. At last, it is found that the rooting depth of the vegetation needs to be described carefully in urban environments with large trees in order not to underestimate the latent heat during summer.

Wouters, Hendrik; Demuzere, Matthias; De Ridder, Koen; van Lipzig, Nicole; Vogel, Gerd

2013-04-01

12

Mapping impervious surface type and sub-pixel abundance using hyperion hyperspectral imagery  

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Impervious surfaces have been identified as an important and quantifiable indicator of environmental degradation in urban settings. A number of research efforts have been directed at mapping impervious surface type using multispectral imagery. To date, however, no studies have compared equivalent techniques using multispectral and hyperspectral imagery to that end. In this study, data from NASA's 220-channel Hyperion instrument were used to: a) delineate three types of impervious surface, and b) map sub-pixel percent abundance for a study site near Washington, D.C., USA. The results were compared with the results of similar methods using same-spatial-resolution Landsat ETM+ data for mapping impervious surface type, and with the results of the U.S. Geological Survey's National Land Cover Data (NLCD) 2001 impervious surface data layer, which is derived from Landsat and high-resolution Ikonos data. The accuracy of discriminating impervious surface type using Hyperion data was assessed at 88% versus Landsat at 59%. The sub-pixel percent impervious map corresponded well with the NLCD 2001; impervious surface in the study area was calculated at 29.3% for NLCD 2001 and 28.4% for the Hyperion-derived layer. The results suggest that fairly simple techniques using hyperspectral data are effective for quantifying impervious surface type, and that high-spectral- resolution imagery may be a good alternative to high-spatial-resolution data.

Falcone, J.A.; Gomez, R.

2005-01-01

13

Mapping long-term temporal change in imperviousness using topographic maps  

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Change in urban land use and impervious surface cover are valuable sources of information for determining the environmental impacts of urban development. However, our understanding of these impacts is limited due to the general lack of historical data beyond the last few decades. This study presents two methodologies for mapping and revealing long-term change in urban land use and imperviousness from topographic maps. Method 1 involves the generation of maps of fractional impervious surface for direct computation of catchment-level imperviousness. Method 2 generates maps of urban land use for subsequent computation of estimates of catchment imperviousness based on an urban extent index. Both methods are applied to estimate change in catchment imperviousness in a town in the South of England, at decadal intervals for the period 1960-2010. The performance of each method is assessed using contemporary reference data obtained from aerial photographs, with the results indicating that both methods are capable of providing good estimates of catchment imperviousness. Both methods reveal that peri-urban developments within the study area have undergone a significant expansion of impervious cover over the period 1960-2010, which is likely to have resulted in changes to the hydrological response of the previously rural areas. Overall, results of this study suggest that topographic maps provide a useful source for determining long-term change in imperviousness in the absence of suitable data, such as remotely sensed imagery. Potential applications of the two methods presented here include hydrological modelling, environmental investigations and urban planning.

Miller, James D.; Grebby, Stephen

2014-08-01

14

EFFECT OF BROKEN IMPERVIOUS IRON LAYER ON WATER AVAILABILITY TO SEMI-ARID NORTHERN GHANAIAN FERRIC LIXISOLS  

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Full Text Available Rainwater is not readily available to sandy loam Ghanaian ferric lixisols. In an attempt to increase water availability to Nyankpala ferric lixisols, their impervious iron pan was broken. Average yield (number of bags of maize from ferric lexisol with ironpan broken was compared with that with iron pan unbroken. At an average annual rainfall of 64.125 to 106.775 mm for Nyampkala, ferric lexisol with or without iron pan broken yielded similar quantity (20-25bgs/ha of maize. Breaking of ironpan alone cannot increase water availability to Nyankpala ferric lixisols. Measures other than the breaking of iron pan are needed to increase water availability to ferreiclesisols and similar soils. Research into sustainable technologies such as permanent amendments for increased soil water availability to ferric lixisol and similar soils is required.

Akwasi Asamoah

2013-03-01

15

A Tetrahedron-Based Endmember Selection Approach for Urban Impervious Surface Mapping  

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The pixel purity index (PPI) and two-dimensional (2-D) scatter plots are two popular techniques for endmember extraction in remote sensing spectral mixture analysis, yet both suffer from one major drawback, that is, the selection of a final set of endmembers has to endure a cumbersome process of iterative visual inspection and human intervention, especially when a spectrally-complex urban scene is involved. Within the conceptual framework of a V-H-L-S (vegetation-high albedo-low albedo-soil) model, which is expanded from the classic V-I-S (vegetation-impervious surface-soil) model, a tetrahedron-based endmember selection approach combined with a multi-objective optimization genetic algorithm (MOGA) was designed to identify urban endmembers from multispectral imagery. The tetrahedron defining the enclosing volume of MNF-transformed pixels in a three-dimensional (3-D) space was algorithmically sought, so that the tetrahedral vertices can ideally match the four components of the adopted model. A case study with Landsat Enhanced Thematic Mapper Plus (ETM+) satellite imagery in Shanghai, China was conducted to verify the validity of the method. The method performance was compared with those of the traditional PPI and 2-D scatter plots approaches. The results indicated that the tetrahedron-based endmember selection approach performed better in both accuracy and ease of identification for urban surface endmembers owing to the 3-D visualization analysis and use of the MOGA. PMID:24892938

Wang, Wei; Yao, Xinfeng; Zhai, Junpeng; Ji, Minhe

2014-01-01

16

Modeling watershed rainfall-runoff relations using impervious surface-area data with high spatial resolution  

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A distributed object-based rainfall-runoff simulation (DORS) model with incorporation of detailed impervious surface-area (ISA) data, derived from digital true-color orthophotography data with high spatial resolution, was developed. This physically based model simulates hydrologic processes of precipitation interception, infiltration, runoff, evapotranspiration, change of soil moisture, change of water-table depth, runoff routing, groundwater routing, and channel-flow routing. The modeling processes take objects based on land-cover types as fundamental spatial units in order to reduce data volume, increase computational efficiency, strengthen representation of watersheds, and utilize the data in variable scales. US Geological Survey stream-gaging data were used to validate the temporal variation of simulated discharge within two watersheds in Rhode Island State. The ratio of absolute error to the mean and the Nash coefficient in the validation period are 7.2% and 0.90 for the first watershed, and 8.0% and 0.77 for the second watershed, respectively. The results indicate that the DORS model is able to capture the relationship between rainfall and runoff in the study area, and that it is applicable in the further study of ISA impacts on the water cycle and associated pollution problems. The results also demonstrate that the performance of the hydrologic simulation is improved with ISA data with high spatial resolution.

Zhou, Yuyu; Wang, Yeqiao; Gold, Arthur J.; August, Peter V.

2010-09-01

17

Atmospheric mercury accumulation and washoff processes on impervious urban surfaces  

Science.gov (United States)

The deposition and transport of mercury (Hg) has been studied extensively in rural environments but is less understood in urbanized catchments, where elevated atmospheric Hg concentrations and impervious surfaces may efficiently deliver Hg to waterways in stormwater runoff. We determined the rate at which atmospheric Hg accumulates on windows, identified the importance of washoff in removing accumulated Hg, and measured atmospheric Hg concentrations to help understand the relationship between deposition and surface accumulation. The main study location was Toronto, Ontario. Similar samples were also collected from Austin, Texas for comparison of Hg accumulation between cities. Windows provided a good sampling surface because they are ubiquitous in urban environments and are easy to clean/blank allowing the assessment of contemporary Hg accumulation. Hg Accumulation rates were spatially variable ranging from 0.82 to 2.7 ng m-2 d-1 in Toronto and showed similar variability in Austin. The highest accumulation rate in Toronto was at the city center and was 5?? higher than the rural comparison site (0.58 ng m-2 d-1). The atmospheric total gaseous mercury (TGM) concentrations were less than 2?? higher between the rural and urban locations (1.7 ?? 0.3 and 2.7 ?? 1.1 ng m-3, respectively). The atmospheric particulate bound fraction (HgP), however, was more than 3?? higher between the rural and urban sites, which may have contributed to the higher urban Hg accumulation rates. Windows exposed to precipitation had 73 ?? 9% lower accumulation rates than windows sheltered from precipitation. Runoff collected from simulated rain events confirmed that most Hg accumulated on windows was easily removed and that most of the Hg in washoff was HgP. Our results indicate that the Hg flux from urban catchments will respond rapidly to changes in atmospheric concentrations due to the mobilization of the majority of the surface accumulated Hg during precipitation events. ?? 2008 Elsevier Ltd.

Eckley, C.S.; Branfireun, B.; Diamond, M.; Van Metre, P.C.; Heitmuller, F.

2008-01-01

18

[Comparison of performances in retrieving impervious surface between hyperspectral (Hyperion) and multispectral (TM/ETM+) images].  

Science.gov (United States)

The retrieval of impervious surface is a hot topic in the remote sensing field in the past decade. Nevertheless, studies on retrieving impervious surface from hyperspectral image and the comparison of the performances in retrieving impervious surface between hyperspectral and multispectral images are rarely reported. Therefore, The present paper focuses on the characteristics of hyperspectral (EO-1 Hyperion) and multispectral (Landsat TM/ETM+) images and implements a complementary study on the comparison based on the retrieved impervious surface information between Hyperion and TM/ETM+ data. For up to 242 bands of Hyperion image, a further study was carried out to select feature bands for impervious surface retrieving using stepwise discriminant analysis. As a result, 11 feature bands were selected and a new image named Hyperion' was thus composed. The new Hyperion' image was used to investigate whether this band-reduced image could obtain higher accuracy in retrieving impervious surface. The three test regions were selected from Fuzhou, Guangzhou and Hangzhou of China, with date-coincident or nearly coincident image pairs of the used sensors. The linear spectral mixture analysis (LSMA) was employed to retrieve impervious surface and the results were accessed for their accuracy. The comparison shows that the Hyperion image has higher accuracy than TM/ETM+, and the Hyperion' composed of the selected 11 feature bands has the highest accuracy. The advantages of Hyperion in spectral and radiometric resolutions over TM/ETM+ are believed to be the main factors contributing to the higher accuracy. The high spectral and radiometric resolutions of Hyperion image allow the sensor to have higher sensitivity in distinguishing subtle spectral changes of ground objects. While, the highest accuracy the 11-band Hyperion' image achieved is owing to the significant reduction of the band dimension of the image and thus the band redundancy. PMID:25007632

Tang, Fei; Xu, Han-Qiu

2014-04-01

19

Synergistic using medium-resolution and high-resolution remote sensing imagery to extract impervious surface for Dianci Basin  

Science.gov (United States)

The knowledge of impervious surfaces, especially the magnitude, location, geometry, spatial pattern of impervious surfaces, is significant to urban ecosystem studies, including urban hydrology, urban climate, land use planning and resource management.Impervious surface area (ISA) is considered a key indicator of environmental quality and can be used to address complex urban environmental issues, particularly those related to the health of urban watersheds. ISA is also an indicator of non-point source pollution or polluted runoff. Remote sensing offers a consistent framework for representing spatial patterns and rates of urbanization over time through accurate observations of impervious surface area. Most of the existing methods of extracting impervious surface based on remote sensing concentrate on an urban scale, but the rapid and accurate methods of extracting impervious surfaces in a basin scale are nearly nonexistent in China and abroad. In recent years,with the rapid urbanization especially surrounding the Dianchi water body, the impervious surface coverage rate also grows rapidly and results in severe degradation of basin water environment within Dianchi watershed. In this study, we developed an approach to extract impervious surface for Dianci Basin by synergistic using medium-resolution and high-resolution remote sensing imagery. Subpixel percent impervious surfaces at Thematic Mapper (TM) images were mapped using the classification and regression tree(CART) algorithm. Sub-pixel impervious surfaces at 30m resolution were mapped in this study area through regression tree models. The estimated ISA results were evaluated through independent ISA reference data derived from high resolution QuickBird. The results prove the suitability of the approach for a widely automated and mapping of impervious surfaces in a basin scale.

Hong, Liang; Yang, Kun; Deng, Ming; Liu, Cun

2014-03-01

20

Urban percent impervious surface and its relationship with land surface temperature in Yantai City, China  

Science.gov (United States)

This study investigated percent impervious surface area (PISA) extracted by a four-endmember normalized spectral mixture analysis (NSMA) method and evaluated the reliability of PISA as an indicator of land surface temperature (LST). Landsat Thematic Mapper (TM) and Enhanced Thematic Mapper Plus (ETM+) images for Yantai city, eastern China obtained from USGS were used as the main data source. The results demonstrated that four-endmember NSMA method performed better than the typical three-endmember one, and there was a strong linear relationship between LST and PISA for the two images, which suggest percent impervious surface area provides an alternative parameter for analyzing LST quantitatively in urban areas.

Yu, Xinyang; Lu, Changhe

2014-03-01

 
 
 
 
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A TECHNIQUE FOR ASSESSING THE ACCURACY OF SUB-PIXEL IMPERVIOUS SURFACE ESTIMATES DERIVED FROM LANDSAT TM IMAGERY  

Science.gov (United States)

We developed a technique for assessing the accuracy of sub-pixel derived estimates of impervious surface extracted from LANDSAT TM imagery. We utilized spatially coincident sub-pixel derived impervious surface estimates, high-resolution planimetric GIS data, vector--to- r...

22

Crucible cast from beryllium oxide and refractory cement is impervious to flux and molten metal  

Science.gov (United States)

Crucible from a mixture of a beryllium oxide aggregate and hydraulic refractory cement, and coated with an impervious refractory oxide will not deteriorate in the presence of fused salt- molten metal mixtures such as uranium- magnesium-zinc-halide salt systems. Vessels cast by this process are used in the flux reduction of oxides of thorium and uranium.

Jastrzebski, Z. D.

1966-01-01

23

Comparing Urban Impervious Surface Identification Using Landsat and High Resolution Aerial Photography  

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Full Text Available This paper evaluates accuracies of selected image classification strategies, as applied to Landsat imagery to assess urban impervious surfaces by comparing them to reference data manually delineated from high-resolution aerial photos. Our goal is to identify the most effective methods for delineating urban impervious surfaces using Landsat imagery, thereby guiding applications for selecting cost-effective delineation techniques. A high-resolution aerial photo was used to delineate impervious surfaces for selected census tracts for the City of Roanoke, Virginia. National Land Cover Database Impervious Surface data provided an overall accuracy benchmark at the city scale which was used to assess the Landsat classifications. Three different classification methods using three different band combinations provided overall accuracies in excess of 70% for the entire city. However, there were substantial variations in accuracy when the results were subdivided by census tract. No single classification method was found most effective across all census tracts; the best method for a specific tract depended on method, band combination, and physical characteristics of the area. These results highlight impacts of inherent local variability upon attempts to characterize physical structures of urban regions using a single metric, and the value of analysis at finer spatial scales.

James B. Campbell

2013-10-01

24

Enhancing endmember selection in multiple endmember spectral mixture analysis (MESMA) for urban impervious surface area mapping using spectral angle and spectral distance parameters  

Science.gov (United States)

Successful retrieval of urban impervious surface area is achieved with remote sensing data using the multiple endmember spectral mixture analysis (MESMA). MESMA is well suited for studying the urban impervious surface area because it allows the number and types of the endmembers to vary on a per-pixel basis, thereby, allowing the control of the large spectral variability. However, MESMA must calculate all potential endmember combinations of each pixel to determine the best-fit one. Therefore, it is a time-consuming and inefficient unmixing technology, especially for hyperspectral images because these images have more complicated endmember categories. Hence, in this paper, we design an improved MESMA (SASD-MESMA: spectral angle and spectral distance MESMA) to enhance the computational efficiency of conventional MESMA, and we validate this new method by analyzing the Hyperion image (Jan-2011) and the field-spectra data of Guangzhou (China). In SASD-MESMA, the parameters of spectral angle (SA) and spectral distance (SD) are used to evaluate the similarity degree between library spectra and image spectra in order to identify the most representative endmember combination for each pixel. Results demonstrate that the SA and SD parameters are useful to reduce misjudgment in selecting candidate endmembers and effective for determining the appropriate endmembers in one pixel. Meanwhile, this research indicates that the proposed SASD-MESMA performs very well in retrieving impervious surface area, forest, grass and soil distributions on the sub-pixel level (the overall root mean square error (RMSE) is 0.15 and the correlation coefficient of determination (R2) is 0.68).

Fan, Fenglei; Deng, Yingbin

2014-12-01

25

Updating the 2001 National Land Cover Database Impervious Surface Products to 2006 using Landsat Imagery Change Detection Methods  

Science.gov (United States)

A prototype method was developed to update the U.S. Geological Survey (USGS) National Land Cover Database (NLCD) 2001 to a nominal date of 2006. NLCD 2001 is widely used as a baseline for national land cover and impervious cover conditions. To enable the updating of this database in an optimal manner, methods are designed to be accomplished by individual Landsat scene. Using conservative change thresholds based on land cover classes, areas of change and no-change were segregated from change vectors calculated from normalized Landsat scenes from 2001 and 2006. By sampling from NLCD 2001 impervious surface in unchanged areas, impervious surface predictions were estimated for changed areas within an urban extent defined by a companion land cover classification. Methods were developed and tested for national application across six study sites containing a variety of urban impervious surface. Results show the vast majority of impervious surface change associated with urban development was captured, with overall RMSE from 6.86 to 13.12% for these areas. Changes of urban development density were also evaluated by characterizing the categories of change by percentile for impervious surface. This prototype method provides a relatively low cost, flexible approach to generate updated impervious surface using NLCD 2001 as the baseline. ?? 2010 Elsevier Inc.

Xian, G.; Homer, C.

2010-01-01

26

Ecologically relevant geomorphic attributes of streams are impaired by even low levels of watershed effective imperviousness  

Science.gov (United States)

Urbanization almost inevitably results in changes to stream morphology. Understanding the mechanisms for such impacts is a prerequisite to minimizing stream degradation and achieving restoration goals. However, investigations of urban-induced changes to stream morphology typically use indicators of watershed urbanization that may not adequately represent degrading mechanisms and commonly focus on geomorphic attributes such as channel dimensions that may be of little significance to the ecological goals for restoration. We address these shortcomings by testing if a measure characterizing urban stormwater drainage system connections to streams (effective imperviousness, EI) is a better predictor of change to ecologically relevant geomorphic attributes than a more general measure of urban density (total imperviousness, TI). We test this for 17 sites in independent watersheds across a gradient of urbanization. We found that EI was a better predictor of all geomorphic variables tested than was TI. Bank instability was positively correlated with EI, while width/depth (a measure of channel incision), bedload sediment depth, and frequency of bars, benches, and large wood were negatively correlated. Large changes in all geomorphic variables were detected at very low levels of EI (change in urban streams, highlighting the dominant role of the stormwater drainage system in efficiently transferring stormwater runoff from impervious surfaces to the stream, as found for ecological indicators. It is likely that geomorphic condition of streams in urbanizing watersheds, particularly those attributes of ecological relevance, can only be maintained if excess urban stormwater flows are kept out of streams through retention and harvesting. The extent to which EI can be reduced within urban and urbanizing watersheds, through techniques such as distributed stormwater harvesting and infiltration, and the components of the hydrologic regime to be addressed, requires further investigation. Urbanization influences stream morphology more than any other land use (Douglas, 2011): it alters hydrology and sediment inputs leading to deepening and widening of streams (Chin, 2006). Concomitantly, urbanization often directly impairs stream morphology through channel and riparian zone interventions, e.g., culverts (Hawley et al., 2012), rock protection (Vietz et al., 2012b), and constricted floodplains (Gurnell et al., 2007). These changes to channel geomorphology in turn contribute to poor in-stream ecological condition (Morley and Karr, 2002; Walsh et al., 2005b; Gurnell et al., 2007; Elosegi et al., 2010).The common conception is that channels undergo gross morphologic alterations if > 10-20% of their watershed is covered by impervious surfaces (total imperviousness, TI; Bledsoe and Watson, 2001; Chin, 2006; Table 1). Many of these studies may, however, underestimate the influence of urbanization by using insensitive channel metrics and assessing streams in early stages of urbanization. Most importantly, TI, as a measure of urban density, may not adequately represent the way in which urbanization alters the master variables of flow and sediment within a watershed.Hydrologists have long recognized that, rather than the proportion of impervious cover within a watershed, it is the proportion that is directly connected to the stream through stormwater drainage systems that may be a better predictor of urban-induced hydrologic change (Leopold, 1968). Referred to as effective imperviousness (EI) the proportion of impervious cover directly connected to the stream through stormwater drainage systems may also be a better predictor of geomorphic response than is TI. Over the last decade a direct measure of EI has been found to be a better predictor of ecological response in urban streams (Walsh et al., 2012), but use of such a metric has not found its way into geomorphic studies even though TI has been found to be ineffective (e.g., Bledsoe et al.,

Vietz, Geoff J.; Sammonds, Michael J.; Walsh, Christopher J.; Fletcher, Tim D.; Rutherfurd, Ian D.; Stewardson, Michael J.

2014-02-01

27

Influence of Vegetation, Impervious Surface and Water Body on Land Thermal Fileld of Karst City  

Directory of Open Access Journals (Sweden)

Full Text Available In order to evaluate the impact of karst Guilin City rapid expansion on urban heat island effect, land surface temperature (LST, seven vegetation indexes (VI, percent impervious surface area (ISA and modified normalized difference water index (MNDWI were retrieved with model from TM image. After the influcence of temporal and spatial variation of vegetation, impervious surface and water body on land thermal field of karst city was studied. Results show that there is a significant negative linear relationship between LST and VI, so is between LST and MNDWI. Howerver, the relationship between LST and ISA shows significant positive linear. From 1989 to 2006, the medium and high vegetation covered area of NDVI>0.4 slashes from 76.89% to 32.65%, and the area without vegetation coverage of NDVI0.9 rises greatly from 12.1% to 32.1%.Those result in the high and sub-high surafce temperature areas rises from 7.9% to 15.9%, the low and sub-low surafce temperature areas drop substantially from 61.8% to 38.9%. Urban heat island effect markedly enhanced. Continuous large impervious surface area is one of the main factors contributing to urban heat island on karst city. But Vegetation on karst hills, urban forest and large water bodies such as rivers and lakes have very great impact on karst urban thermal environment and mitigate urban heat island.

HU Dao-sheng

2014-05-01

28

Importance of High-Resolution LiDAR Data in Modeling Runoff Levels Over Impervious Surfaces  

Science.gov (United States)

Directly connected impervious areas collect and deliver unfiltered runoff to modified and impacted waterways. Modeling water flow over the landscape is an effective method of observing drainage patterns and predicting pollutant and sediment loadings. Improved models applying high-resolution elevation data can identify key areas with high pollutant output. This is a crucial issue in the Lake Tahoe Basin where lakeshore urban development has increased and lake clarity has been declining for years. This study aims to evaluate an integrated LiDAR and GIS-based modeling approach that uses a fine-scaled ground surface and impervious surface connectivity to predict the pollutant load in the Lake Tahoe Basin This study produced a fine-scaled surface model of nine subset catchments in the South Tahoe basin, including areas of low (below 20%), medium (30% to 50%) and high (above 50%) impervious surface cover. Our method integrated LiDAR, multispectral imagery, and GIS data to develop accurate terrain models, hydrologic routing, and directly connected impervious area layers for the Lake Tahoe basin. The high-density ground and object elevation data collected using Light Detection and Ranging (LiDAR) creates an accurate picture of water flow over the land, and obstacles to the flow such as buildings. High-resolution LiDAR data was obtained from the Round 10 Lake Tahoe Southern Nevada Public Land Management capital program from the year 2010. This data was processed to create a digital elevation model of the ground surface. Land use classification used object height information from the LiDAR cloud, NAIP 4-band images with 1-meter resolution and a normalized difference vegetation index image derived from the NAIP imagery. The US Army Core of Engineers hydrologic modeling system (HEC-HMS) will be used to model runoff. Based on long-term simulations the effect of directly connected impervious area on rainfall-runoff characteristics for the South Lake Tahoe catchments will be evaluated. Similar scenarios will be run on data derived from 10-meter resolution USGS elevation models. Regression analyses will be used to compare the simulation results derived using LiDAR data inputs to the results obtained using lower-resolution USGS elevation models and to observed monitoring data.

Melosh, C.; Rao, M.

2013-12-01

29

Determining Trends in Impervious Cover for the Mobile Bay, AL Region for 1974-2008, Based on a Landsat Time Series  

Science.gov (United States)

This presentation will discuss the development and use of Landsat-based impervious cover products in conjunction with land use land cover change products to assess multi-decadal urbanization across the Mobile Bay region at regional and watershed scales. This nationally important coastal region has undergone a variety of ephemeral and permanent land use land cover change since the mid-1970s, including gradual but consequential increases in urban surface cover. This urban sprawl corresponds with increased regional percent impervious cover. The region s coastal zone managers are concerned about the increasing percent impervious cover, since it can negatively influence water quality and is an important consideration for coastal conservation and restoration work. In response, we processed multi-temporal Landsat data to compute maps of percent impervious cover for multiple dates from 1974 through 2008, roughly at 5-year intervals. Each year of product was classified using one single date of leaf-on and leaf-off Landsat data in conjunction with Cubist software. We are assessing Landsat impervious cover product accuracy through comparisons to available reference data, including available NLCD impervious cover products from the USGS, raw Landsat data, plus higher spatial resolution aerial and satellite data. In particular, we are quantitatively comparing the 2008 Landsat impervious cover products to those from QuickBird 2.4-meter multispectral data. Initial visual comparisons with the QuickBird impervious cover product suggest that the 2008 Landsat product tends to underestimate impervious cover for high density urban areas and to overestimate impervious cover in established residential subdivisions mixed with forested cover. Landsat TM and ETM data appears to produce more accurate impervious cover products compared to those using lower resolution Landsat MSS data. Although imperfect, these Landsat impervious cover products have helped the Mobile Bay National Estuary Program visualize basic urbanization trends for multiple HUC-12 watersheds of concern to them and their constituents

Spruce, Joseph P.; Smoot, James; Ellis, Jean; Swann, Roberta

2011-01-01

30

Assessing Changes in Impervious Area Using Land Use Maps of Different Resolution in the Croton NY City Water Supply Watershed  

Science.gov (United States)

With the advance of remote sensing, options arise for the hydrologic modeler to access both public domain and privately contracted watershed land cover maps. Land use classification processes using aerial photographs are highly variable depending on tools and training, but distinction between impervious and pervious land cover is relatively simple. Hydrologic models will estimate different runoff timing, volume, and water quality depending on the percent imperviousness of the watershed. This research will examine how percent imperviousness varies with changes in both radiometric and spatial land cover map resolution. WinHSPF was run with four distinct land cover maps derived from remote imagery: MRLC (30 m), LULC (1 km), contracted aerial photos (1 m), and processed digital (1 M) ortho quarter quads. Comparisons were made between map percent impervious cover and runoff timing and volume. A modified export coefficient model that tracks pollutant discharge through down gradient filters examined how estimated nutrient loading changed with differences in these land cover map products. Methods are suggested for updating estimates of percent impervious cover in coarser resolution maps using field data or other means.

Somerlot, C.; Duncan, J.; Endreny, T.

2001-05-01

31

Soils  

Science.gov (United States)

The purpose of the handout is to identify the three major types of soils: pedalfer, pedocal, and laterite, and to understand the soil profile. This is accomplished with brief descriptions of the soil horizons and the designation of common elements to pedalfers, pedocals, and laterite soils. The handout is concluded with a discussion of soil erosion. Links are provided to the online Physical Geology resources at Georgia Perimeter College.

Gore, Pamela

1995-08-29

32

Soils  

...Directive:Identification of areas at risk of soil erosion, organic matter decline, compaction, salinisation and landslides and for Member States to establish programmes of measuresMeasures to address soil contamination...

33

Effects of impervious pavements on reducing runoff in an arid urban catchment  

Science.gov (United States)

The progressive urbanization of US arid and semi-arid southwestern territories has transformed undeveloped aridlands into dynamic, radially expanding metropolitan centers. As these mature, infill development further reduces undeveloped area, inversely coupling surface imperviousness to infiltration rates, with a subsequent increase in runoff generation. Intensified runoff carries undesirable environmental consequences, magnifying urban flooding events and concentrations, transport, and propagation of contaminants. Pervious pavements offer one potential solution for decreased urban infiltration. At present, the application potential of pervious pavements as an effective urban infiltration management tool exceeds its exploitation. While entirely eliminating urban Total Impervious Area is not a feasible solution, pervious pavements significantly reduce Effective Impervious Area at costs competitive with traditional Best Management Practices. Previous research into pervious pavements has largely consisted of laboratory prototypes or small-scale field experiments, with a heavy bias towards parking lots. In this study we explore the effectiveness of pervious pavements in increasing infiltration, thus decreasing runoff volume during summer monsoonal and winter convective rainfall events in an 8 ha residential catchment in Scottsdale, Arizona. Analysis focuses on the interaction dynamics between surface area of pervious pavement application and its net effect on runoff response at the catchment level. Hydrological response was modeled using MAHLERAN (Model for Assessing Hillslope-Landscape Erosion, Runoff and Nutrients), a spatially explicit, event-based model, parameterized at a spatial resolution of 0.25 sq m. Data for model parameterization was obtained from analysis of aerial imagery and field-based monitoring of surface properties. The model was tested against measurements of flow at the catchment outlet for multiple rainfall events with total event rainfall ranging from 5 mm to 25 mm. Model testing shows total event discharge simulated well, although low Nash-Sutcliffe coefficients for events indicate a poor fit between the shape and timing of the modeled and monitored hydrograph, which we attribute to poor characterization of friction factors in urban catchments. Scenario-based model analysis tested catchment response to substitution of pervious for conventional pavement by percent and pavement-function scenarios. Results are consistent with previous findings in that short duration-high intensity storms trigger threshold infiltration capacity, past which pervious pavement damping of runoff volume levels off, approaching conventional levels. However at the modeled catchment scale, this initial damping represents a significant reduction in volume, peak flow velocity, and contaminant loading potential. Urban surface drainage networks concentrate and channel flow along roads: the capacity of pervious pavements to simultaneously increase infiltration directly at location of greatest runoff and mitigate inflow effects from remote points has compelling potential as a hydrologic and urban systems engineering tool.

Epshtein, O.; Turnbull, L.; Earl, S.

2011-12-01

34

Understanding spatial-temporal urban expansion pattern (1990-2009) using impervious surface data and landscape indexes: a case study in Guangzhou (China)  

Science.gov (United States)

A new viewpoint for understanding the urban expansion using impervious surface information, which is obtained using remote sensing imagery is presented. The purpose of this study is to understand and describe the urban expansion pattern with the view of impervious surfaces instead of the conventional view of land use/land cover. Six years' worth of impervious surface data (1990-2009) of Guangzhou are extracted via linear spectral unmixing analysis methods and spatial and temporal characteristics are discussed in detail. The area, density, and gravity centers changes of the impervious surfaces are analyzed to explain internal/external urban expansion. Meanwhile, five landscape indexes, such as patch density, edge density, mean patch size, area-weighted, and fragmentation index, are utilized to describe landscape changes of Guangzhou in past 20 years, which are influenced deeply by the impervious surface expansion. In order to detail landscape changes, two transects corresponding to the two urban expansion directions are designed and five landscape metrics in these two transects are reported. Conclusions can be drawn and shown as following: (1) temporally, the area of impervious surfaces increases from 12,998 to 59,911 ha from 1990 to 2009. The amount of impervious surface varies in different periods. The annual growth rates of impervious surface area during 1990-1995, 1995-1998, and 1998-2000 are 10.16%, 11.61%, and 10.78%, respectively; (2) annual growth rates decrease from 10.78% (1998-2000) to 5.67% (2000-2003). Nevertheless, from 2003-2009, the annual growth rate has a slight increase compared to a former period. The rate is 5.91% (3) spatially, gravity centers of medium and high percentage impervious surfaces migrate slightly; and (4) according to the gradient analysis in the two transects, it can be observed that the high percentage of impervious surface increases gradually in new city districts (from west to east and from south to north).

Fan, Fenglei; Fan, Wei

2014-01-01

35

Soil  

International Nuclear Information System (INIS)

Environmental soil surveys in each province of Austria have been performed, soils of about 5,000 sites were described and analyzed for nutrients and pollutants, the majority of these data are recorded in the soil information system of Austria (BORIS) soil database, http://www.ubavie.gv.at/umweltsituation/boden/boris), which also contains a soil map of Austria, data from 30 specific investigations mainly in areas with industry and results from the Austria - wide cesium investigation. With respect to the environmental state of soils a short discussion is given, including two geographical charts, one showing which sites have soil data (2001) and the other the cadmium distribution in top soils according land use (forest, grassland, arable land, others). Information related to the soil erosion, Corine land cover (Europe-wide land cover database), evaluation of pollutants in soils (reference values of As, Cd, Co, Cr, Cu, Hg, Mo, Ni, Se, Pb, Tl, Va, Zn, AOX, PAH, PCB, PCDD/pcdf, dioxin), and relevant Austrian and European standards and regulations is provided. Figs. 2, Tables 4. (nevyjel)

36

Soils  

International Nuclear Information System (INIS)

For Austria there exists a comprehensive soil data collection, integrated in a GIS (geographical information system). The content values of pollutants (cadmium, mercury, lead, copper, mercury, radio-cesium) are given in geographical charts and in tables by regions and by type of soil (forests, agriculture, greenland, others) for the whole area of Austria. Erosion effects are studied for the Austrian region. Legal regulations and measures for an effective soil protection, reduction of soil degradation and sustainable development in Austria and the European Union are discussed. (a.n.)

37

Soil structural behaviour of flooded soils  

International Nuclear Information System (INIS)

The objectives of this presentation are to: identify factors determining of the structural behaviour of flooded soils, as compared to those acting in upland soils; analyse the influence of reductive processes on aggregate stabilising agents; discuss mechanisms of structural deterioration and recovery during the flooding-drying cycle, on the basis of a case study: cattle trampling effects in the flooding Pampa of Argentina. Flooded soils, now known as Hydric soils, are characteristic of wetlands and irrigated fields cropped to rice (paddy soils). In them, water covers the soil, or is present either at or near the surface of the soil all year or for varying periods of time during the year. Hydric soils belong to different taxa of the FAO-UNESCO Soil Map (2000). Fluvisols, Planosols and Gleysols are widespread distributed in the globe. The generation of redoximorphic features is due to different causes in each of them. Fluvisols are covered part of the year by surface water from river overflows; Planosols are soils having an impervious Bt horizon, supporting perched water during short periods; and Gleysols are soils affected by stagnant water tables during long periods

38

Assessing the impact of urbanization on storm runoff in a peri-urban catchment using historical change in impervious cover  

Science.gov (United States)

This paper investigates changes in storm runoff resulting from the transformation of previously rural landscapes into peri-urban areas. Two adjacent catchments (?5 km2) located within the town of Swindon in the United Kingdom were monitored during 2011 and 2012 providing continuous records of rainfall, runoff and actual evaporation. One catchment is highly urbanized and the other is a recently developed peri-urban area containing two distinct areas of drainage: one with mixed natural and storm drainage pathways, the other entirely storm drainage. Comparison of observed storm hydrographs showed that the degree of area serviced by storm drainage was a stronger determinant of storm runoff response than either impervious area or development type and that little distinction in hydrological response exists between urban and peri-urban developments of similar impervious cover when no significant hydraulic alteration is present. Historical levels of urbanization and impervious cover were mapped from the 1960s to the 2010s based on digitized historical topographic maps and were combined with a hydrological model to enable backcasting of the present day storm runoff response to that of the catchments in their earlier states. Results from the peri-urban catchment showed an increase in impervious cover from 11% in the 1960s to 44% in 2010s, and introduction of a large-scale storm drainage system in the early 2000s, was accompanied by a 50% reduction in the Muskingum routing parameter k, reducing the characteristic flood duration by over 50% while increasing peak flow by over 400%. Comparisons with changes in storm runoff response in the more urban area suggest that the relative increase in peak flows and reduction in flood duration and response time of a catchment is greatest at low levels of urbanization and that the introduction of storm water conveyance systems significantly increases the flashiness of storm runoff above that attributed to impervious area alone. This study demonstrates that careful consideration is required when using impervious cover data within hydrological models and when designing flood mitigation measures, particularly in peri-urban areas where a widespread loss in pervious surfaces and alteration of drainage pathways can significantly alter the storm runoff response. Recommendations include utilizing more refined urban land use typologies that can better represent physical alteration of hydrological pathways.

Miller, James D.; Kim, Hyeonjun; Kjeldsen, Thomas R.; Packman, John; Grebby, Stephen; Dearden, Rachel

2014-07-01

39

Evaluating the effectiveness of drainage and impervious elements of concrete dams on bedrock (on example of Bureyskaya HPP  

Directory of Open Access Journals (Sweden)

Full Text Available The proposed technique allows estimating the efficiency of individual elements of hydraulic structures that perform similar functions and work together, and determining the impact of their current state on the entire structure performance. The technique was elaborated for a separate evaluation of drainage and impervious elements of bases of concrete dams on bedrock when they work together. To implement this task, the authors used the method of numerical simulation (modeling and comparisons with field observations data, which allowed calibrating the ground model. The technique was tested on one of the gates at Bureyskaya HPP, and the influence of drainage and impervious elements effectiveness upon the backpressure on the base of the concrete dam was estimated. The result of these studies allows the authors to suggest appropriate safety criteria K1 and K2. It should be noted that the developed technique allows giving priorities in determining the composition and volume of the repair and / or reconstruction of hydraulic structures elements.

S.V. Solsky

2014-06-01

40

Fabrication of gas impervious edge seal for a bipolar gas distribution assembly for use in a fuel cell  

International Nuclear Information System (INIS)

A process is described for the preparation of a bipolar gas reactant distribution assembly having solid, gas impervious edge seals to prevent leakage of gaseous reactants, which comprises providing a pair of porous plate members provided with peripheral slits, the slits being generally parallel to, and spaced from each of two edges of the plate, filling the slits with a non-porous, fusible gas impervious edge sealing compound, assembling the plate members with the slits therein approximately perpendicular to one another and a layer of fusible sealing material interposed therebetween, hot pressing the assembly at a temperature sufficient to cause a redistribution of the sealant layer into the pores of the adjacent plate surfaces and the edge sealing compound to flow and impregnate the region of the plates adjacent the slits and comingle with the redistributed sealant material to form a continuous layer of sealant along the edges of the assembly

 
 
 
 
41

Understanding the effects of the impervious surfaces pattern on land surface temperature in an urban area  

Science.gov (United States)

It is well known that urban impervious surface (IS) has a warming effect on urban land surface temperature (LST). However, the influence of an IS's structure, components, and spatial distribution on LST has rarely been quantitatively studied within strictly urban areas. Using ETM+ remote sensing images from the downtown area of Shanghai, China in 2010, this study characterized and quantified the influence of the IS spatial pattern on LST by selecting the percent cover of each IS cover feature and ten configuration metrics. The IS fraction was estimated by linear spectral mixture analysis (LSMA), and LST was retrieved using a mono-window algorithm. The results indicate that high fraction IS cover features account for the majority of the study area. The high fraction IS cover features are widely distributed and concentrated in groups, which is similar with that of high temperature zones. Both the percent composition and the configuration of IS cover features greatly affect the magnitude of LST, but the percent composition is a more important factor in determining LST than the configuration of those features. The significances and effects of the given configuration variables on LST vary greatly among IS cover features.

Nie, Qin; Xu, Jianhua

2014-09-01

42

Relative importance of impervious area, drainage density, width function, and subsurface storm drainage on flood runoff from an urbanized catchment  

Science.gov (United States)

The literature contains contradictory conclusions regarding the relative effects of urbanization on peak flood flows due to increases in impervious area, drainage density and width function, and the addition of subsurface storm drains. We used data from an urbanized catchment, the 14.3 km2 Dead Run watershed near Baltimore, Maryland, USA, and the physics-based gridded surface/subsurface hydrologic analysis (GSSHA) model to examine the relative effect of each of these factors on flood peaks, runoff volumes, and runoff production efficiencies. GSSHA was used because the model explicitly includes the spatial variability of land-surface and hydrodynamic parameters, including subsurface storm drains. Results indicate that increases in drainage density, particularly increases in density from low values, produce significant increases in the flood peaks. For a fixed land-use and rainfall input, the flood magnitude approaches an upper limit regardless of the increase in the channel drainage density. Changes in imperviousness can have a significant effect on flood peaks for both moderately extreme and extreme storms. For an extreme rainfall event with a recurrence interval in excess of 100 years, imperviousness is relatively unimportant in terms of runoff efficiency and volume, but can affect the peak flow depending on rainfall rate. Changes to the width function affect flood peaks much more than runoff efficiency, primarily in the case of lower density drainage networks with less impermeable area. Storm drains increase flood peaks, but are overwhelmed during extreme rainfall events when they have a negligible effect. Runoff in urbanized watersheds with considerable impervious area shows a marked sensitivity to rainfall rate. This sensitivity explains some of the contradictory findings in the literature.

Ogden, Fred L.; Raj Pradhan, Nawa; Downer, Charles W.; Zahner, Jon A.

2011-12-01

43

MULTI-SCALE REMOTE SENSING MAPPING OF ANTHROPOGENIC IMPERVIOUS SURFACES: SPATIAL AND TEMPORAL SCALING ISSUES RELATED TO ECOLOGICAL AND HYDROLOGICAL LANDSCAPE ANALYSES  

Science.gov (United States)

Anthropogenic impervious surfaces are leading contributors to non-point-source water pollution in urban watersheds. These human-created surfaces include such features as roads, parking lots, rooftops, sideways, and driveways. Aerial photography provides a historical vehicle for...

44

Automated mapping of sub-pixel impervious surface area from landsat imagery  

Science.gov (United States)

The past few decades have seen rapid, global urbanization. Remotely sensed imagery is the best source of information about the extent of urbanization, but extracting urban extent from remotely sensed imagery is often an intensive, supervised task for analysts to perform. This project presents a fully automated method to extract impervious surface area (ISA), an important component of urban expansion, from Landsat TM and similar sensors. These moderate resolution sensors have a multi-decade collection archive, sub-monthly revisit rate and have served as a model for other national and commercial programs. The unsupervised methodology proposed herein, termed the PEEL process (pre-processing, endmember extraction and labeling), is an SMA (spectral mixture analysis) technique that uses as inputs endmembers that have been labeled by a SVM (support vector machine) classification through the fusion of the PanTex GLCM-based texture measure and endmembers drawn from the SMACC (sequential maximum angle convex cone) algorithm. Labels are provided to endmembers with an overall accuracy of 94% across 13 Landsat scenes from different sensor types and of several regions and urban forms. Multiple unmixing methods are tested, with BNMESMA (brightness normalized multiple endmember spectral mixture analysis) performing the best with a RMSE of 0.276. Caution is given regarding the value of RMSE as a metric for comparing method accuracy and more detailed error metrics are introduced. The method is shown as a viable template for mapping ISA across multiple scenes and as a useful framework for analyzing large archives of imagery with a common, automatable methodology.

Kamphaus, Benjamin D.

45

Performance of heterogeneous earthfill dams under earthquakes: optimal location of the impervious core  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Earthfill dams are man-made geostructures which may be especially damaged by seismic loadings, because the soil skeleton they are made of suffers remarkable modifications in its mechanical properties, as well as changes of pore water pressure and flow of this water inside their pores, when subjected to vibrations. The most extreme situation is the dam failure due to soil liquefaction. Coupled finite element numerical codes are a useful tool to assess the safety of these dams. In this paper th...

Lo?pez-querol, S.; Moreta, P. J. M.

2008-01-01

46

Quantification of Impervious Surfaces Along the Wasatch Front, Utah: AN Object-Based Image Analysis Approach to Identifying AN Indicator for Wetland Stress  

Science.gov (United States)

The Remote Sensing/GIS Laboratory at Utah State University, in cooperation with the United States Environmental Protection Agency, is quantifying impervious surfaces for three watershed sub-basins in Utah. The primary objective of developing watershed-scale quantifications of impervious surfaces is to provide an indicator of potential impacts to wetlands that occur within the Wasatch Front and along the Great Salt Lake. A geospatial layer of impervious surfaces can assist state agencies involved with Utah's Wetlands Program Plan (WPP) in understanding the impacts of impervious surfaces on wetlands, as well as support them in carrying out goals and actions identified in the WPP. The three watershed sub-basins, Lower Bear-Malad, Lower Weber, and Jordan, span the highly urbanized Wasatch Front and are consistent with focal areas in need of wetland monitoring and assessment as identified in Utah's WPP. Geospatial layers of impervious surface currently exist in the form of national and regional land cover datasets; however, these datasets are too coarse to be utilized in fine-scale analyses. In addition, the pixel-based image processing techniques used to develop these coarse datasets have proven insufficient in smaller scale or detailed studies, particularly when applied to high-resolution satellite imagery or aerial photography. Therefore, object-based image analysis techniques are being implemented to develop the geospatial layer of impervious surfaces. Object-based image analysis techniques employ a combination of both geospatial and image processing methods to extract meaningful information from high-resolution imagery. Spectral, spatial, textural, and contextual information is used to group pixels into image objects and then subsequently used to develop rule sets for image classification. eCognition, an object-based image analysis software program, is being utilized in conjunction with one-meter resolution National Agriculture Imagery Program (NAIP) aerial photography from 2011.

Leydsman-McGinty, E. I.; Ramsey, R. D.; McGinty, C.

2013-12-01

47

Laboratory analysis of a system for catchment, pre-treatment and treatment (SCPT) of runoff from impervious pavements.  

Science.gov (United States)

This article reports the development and construction of a 1:1 scale laboratory prototype of a System for Catchment, Pre-treatment and Treatment (SCPT) of runoff polluted by contaminants washed from impervious pavements. The concept of the SCPT is an online system with an up-flow filter. The filter is composed of geotextile layers and limestone. The laboratory tests carried out were focused on determining the SCPT prototype behaviour under different working conditions. The variables studied were: inflow, pollutant loads and filtration system configuration. The results show that the system designed has a high capacity for treatment of solids and oil, with an average efficiency of 85% and 97% respectively. Moreover, the regression equations of the treatment efficiency were determined for each of the pollutants studied, for different inflow conditions and pollution loads. PMID:20371944

Fernández-Barrera, A H; Rodriguez-Hernandez, J; Castro-Fresno, D; Vega-Zamanillo, A

2010-01-01

48

Mapping Impervious Surface Expansion using Medium-resolution Satellite Image Time Series: A Case Study in the Yangtze River Delta, China  

Science.gov (United States)

Cities have been expanding rapidly worldwide, especially over the past few decades. Mapping the dynamic expansion of impervious surface in both space and time is essential for an improved understanding of the urbanization process, land-cover and land-use change, and their impacts on the environment. Landsat and other medium-resolution satellites provide the necessary spatial details and temporal frequency for mapping impervious surface expansion over the past four decades. Since the US Geological Survey opened the historical record of the Landsat image archive for free access in 2008, the decades-old bottleneck of data limitation has gone. Remote-sensing scientists are now rich with data, and the challenge is how to make best use of this precious resource. In this article, we develop an efficient algorithm to map the continuous expansion of impervious surface using a time series of four decades of medium-resolution satellite images. The algorithm is based on a supervised classification of the time-series image stack using a decision tree. Each imerpervious class represents urbanization starting in a different image. The algorithm also allows us to remove inconsistent training samples because impervious expansion is not reversible during the study period. The objective is to extract a time series of complete and consistent impervious surface maps from a corresponding times series of images collected from multiple sensors, and with a minimal amount of image preprocessing effort. The approach was tested in the lower Yangtze River Delta region, one of the fastest urban growth areas in China. Results from nearly four decades of medium-resolution satellite data from the Landsat Multispectral Scanner (MSS), Thematic Mapper (TM), Enhanced Thematic Mapper plus (ETM+) and China-Brazil Earth Resources Satellite (CBERS) show a consistent urbanization process that is consistent with economic development plans and policies. The time-series impervious spatial extent maps derived from this study agree well with an existing urban extent polygon data set that was previously developed independently. The overall mapping accuracy was estimated at about 92.5% with 3% commission error and 12% omission error for the impervious type from all images regardless of image quality and initial spatial resolution.

Gao, Feng; DeColstoun, Eric Brown; Ma, Ronghua; Weng, Qihao; Masek, Jeffrey G.; Chen, Jin; Pan, Yaozhong; Song, Conghe

2012-01-01

49

Fabrication of gas impervious edge seal for a bipolar gas distribution assembly for use in a fuel cell  

Science.gov (United States)

A bipolar gas reactant distribution assembly for use in a fuel cell is disclosed, the assembly having a solid edge seal to prevent leakage of gaseous reactants wherein a pair of porous plates are provided with peripheral slits generally parallel to, and spaced apart from two edges of the plate, the slit being filled with a solid, fusible, gas impervious edge sealing compound. The plates are assembled with opposite faces adjacent one another with a layer of a fusible sealant material therebetween the slits in the individual plates being approximately perpendicular to one another. The plates are bonded to each other by the simultaneous application of heat and pressure to cause a redistribution of the sealant into the pores of the adjacent plate surfaces and to cause the edge sealing compound to flow and impregnate the region of the plates adjacent the slits and comingle with the sealant layer material to form a continuous layer of sealant along the edges of the assembled plates.

Kaufman, Arthur (West Orange, NJ); Werth, John (Princeton, NJ)

1986-01-01

50

Relationships Between Litter Processing and Impervious Surface Cover in Headwater Tributaries of the St. Johns River, Florida  

Science.gov (United States)

We investigated relationships between land-use and litter processing in 18 tributaries of the St. Johns River, Florida. The percent total impervious area (PTIA) of these catchments ranged from 0-66%. We measured mass loss and fungal biomass (as ergosterol) and associated macroinvertebrate biomass for 2 litter species (red maple [Acer rubrum] and sweetgum [Liquidambar styraciflua]). Processing rates ranged from 0.010-0.046d-1 for maple and 0.006-0.018d-1 for sweetgum. The fastest processing occurred at intermediate PTIA. Fungal biomass peaked at 24 days with the lowest biomass occurring in the low PTIA stream. Rates of processing were positively related to both mean macroinvertebrate biomass and taxa richness. Shredder biomass was not related to maple, but was negatively related to sweetgum processing. Scraper biomass peaked at intermediate PTIA, and was positively related to processing rates for both leaf species. We reduced correlated physicochemical, land-use and biological variables to several orthogonal variables using principle components analysis. Regression models based on these variables accounted for 70% of the variance in processing rates for both leaf species. Collectively, these results demonstrate that PTIA and other land-use indicators are associated with differences in stream ecosystem patterns and processes between low gradient, subtropical streams.

Chadwick, M. A.; Dobberfuhl, D. R.; Benke, A. C.; Huryn, A. D.; Suberkropp, K.; Thiele, J. E.

2005-05-01

51

Extraction and Analysis of Impervious Surfaces Based on a Spectral Un-Mixing Method Using Pearl River Delta of China Landsat TM/ETM+ Imagery from 1998 to 2008  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Impervious surface area (ISA) is considered as an indicator of environment change and is regarded as an important input parameter for hydrological cycle simulation, water management and area pollution assessment. The Pearl River Delta (PRD), the 3rd most important economic district of China, is chosen in this paper to extract the ISA information based on Landsat images of 1998, 2003 and 2008 by using a linear spectral un-mixing method and to monitor impervious surface change by analyzing the ...

Renrong Chen; Fenglei Fan; Yingbin Deng

2012-01-01

52

Quantifying the Spatial Configuration of Impervious Cover and its Effect on Runoff Generation in the Whiteoak Bayou Watershed In Texas  

Science.gov (United States)

This study examines the relationship between the developing landscape and the water flowing through it in the Whiteoak Bayou watershed located in the coastal plains in Harris County, Texas, on the northwest outskirts of Houston. The area was 223-km2 and the analysis period spanned from January 1, 1949, to December 31, 2000. Daily streamflow data for the 52 years was obtained from USGS and coincident precipitation data was obtained from NOAA. Georeferenced parcel-level land use data was obtained from the Harris County Appraisal District with sufficient detail to determine the parcel area, the year of development, and the building area. Watershed boundaries were obtained from the Harris County Flood Control District. The analysis of the flow series showed striking changes in the flow regime around years 1972 and 1985, which were not associated to changes in the somewhat steady increasing trend of the watershed total developed area or impervious cover. This study aimed at determining measures of development that could explain the flow regime changes in the Whiteoak Bayou watershed. As part of the analysis, geographic information systems (GIS) and spatial metrics were utilized to describe the changes in the broad-scale patterns of the human-developed portion of the landscape, and to relate them to changes in streamflow over time. FRAGSTATS was used to quantify spatial patterns in the developed landscape on an annual basis. It was found that models based on the spatial configuration of the developed landscape capture better the flow regime changes. In particular, it was found that the decline in the number of developed patches, caused by the filling of the gaps in the built areas, coincided with an identifiable increase in flow rates.

Olivera, F.; Defee, B. B.

2005-12-01

53

Early electrophysiological indices of illusory contour processing within the lateral occipital complex are virtually impervious to manipulations of illusion strength.  

Science.gov (United States)

The visual system can automatically interpolate or "fill-in" the boundaries of objects when inputs are fragmented or incomplete. A canonical class of visual stimuli known as illusory-contour (IC) stimuli has been extensively used to study this contour interpolation process. Visual evoked potential (VEP) studies have identified a neural signature of these boundary completion processes, the so-called IC-effect, which typically onsets at 90-110 ms and is generated within the lateral occipital complex (LOC). Here we set out to determine the delimiting factors of automatic boundary completion with the use of illusory contour stimuli and high-density scalp recordings of brain activity. Retinal eccentricity, ratio of real to illusory contours (i.e. support ratio), and inducer diameter were each varied parametrically, and any resulting effects on the amplitude and latency of the IC-effect were examined. Somewhat surprisingly, the amplitude of the IC-effect was found to be impervious to all changes in these stimulus parameters, manipulations that are known to impact perceived illusion strength. Thus, this automatic stage of object processing appears to be a binary process in which, so-long as minimal conditions are met, contours are automatically completed. At the same time, the latency of the IC-effect was found to vary inversely with support ratio, likely reflecting the additional time necessary to interpolate across the relatively longer induced boundaries of the implied object. These data are interpreted in the context of a two stage object-recognition model that parses processing into an early automatic perceptual stage that is followed by a more effortful conceptual processing stage. PMID:22037001

Altschuler, Ted S; Molholm, Sophie; Russo, Natalie N; Snyder, Adam C; Brandwein, Alice B; Blanco, Daniella; Foxe, John J

2012-02-15

54

Influence of cracking in the desiccation process of clay soils  

Digital Repository Infrastructure Vision for European Research (DRIVER)

It is well known that clayey soils undergoing desiccation tend to shrink and eventually crack. Analysis of the behaviour and influence of cracks in these types of soils is very important in several engineering fields such as mine tailing dams, long-term radioactive waste storage, impervious core of earth dams, and in any situation where clay is used as a barrier to fluid flow. Loss of humidity and cracking changes the permeability of such barriers that may no longer work properly and pose pot...

Levatti, Hector Ulises; Prat Catala?n, Pere; Ledesma Villalba, Alberto

2009-01-01

55

Surface and Ground Water Regime in Bi?-field Soils  

Directory of Open Access Journals (Sweden)

Full Text Available The aim of this work was to determine, through several-years stationary investigations, the water regime of soils in the Bi?-field district. Investigations were carried out during a three-year period (2001-2003 on 8,700 ha of agricultural areas. Detailed hydropedological investigations were done in 2000 and a soil map of the district (scale 1:10,000 was produced. Five pedosystematic units were detected: semigley, pseudogleyed, eugley hypogley, eugley amphigley, humogley, and drained soils. Based on three-year continuing monitoring of surface and ground waters the following main types of moistening of the soils were identifi ed: eugley-pseudogley, hypogley, amphigley and drained. Stochastic relation between the Sava and Bi? water levels and groundwater in the agrological profile of studied soils was determined by crosscorrelation with one decade shift s (c = 1. It was found that the ground waters in the profi les of studied soils communicate more intensively with the River Bi? water (r = 0.65-0.69 compared to the River Sava water (r = 0.23-0.69.This especially applies to ground water of hypogley soils, which cover 57% of the studied area. Marked vertical communication of ground water in the deep aquifer with water of the shallow soil aquifer was detected, indicating that the surface layer, mainly made up of silty clayey loams, is not impervious.

Ivan Musta?

2007-03-01

56

Exploring the Influence of Impervious Surface Density and Shape on Urban Heat Islands in the Northeast USA Using MODIS and Landsat  

Science.gov (United States)

Impervious surface area (ISA) from the National Land Cover Database (NLCD) 2001 and land surface temperature (LST) from MODIS averaged over three annual cycles (2003-2005) are used in a spatial analysis to assess the urban heat island (UHI) signature and its relationship to settlement size and shape, development intensity distribution, and land cover composition for 42 urban settlements embedded in forest biomes in the Northeastern United States. Development intensity zones, based on percent ISA, are defined for each urban area emanating outward from the urban core to nearby rural areas and are used to stratify land surface temperature. The stratification is further constrained by biome type and elevation to insure objective intercomparisons between urban zones within an urban settlement and between settlements. Stratification based on ISA allows the definition of hierarchically ordered urban zones that are consistent across urban settlements and scales. In addition to the surrounding ecological context, we find that the settlement size and shape as well as the development intensity distribution significantly influence the amplitude of summer daytime UHI. Within the Northeastern US temperate broadleaf mixed forest, UHI magnitude is positively related to the logarithm of the urban area size. Our study indicates that for similar urban area sizes, the development intensity distribution is one of the major drivers of UHI. In addition to urban area size and development intensity distribution, this analysis shows that both the shape of the urban area and the land cover composition in the surrounding rural area play an important role in modulating the UHI magnitude in different urban settlements. Our results indicate that remotely sensed urban area size and shape as well as the development intensity distribution influence UHI amplitude across regional scales.

Zhang, Ping; Imhoff, Marc L.; Bounoua, Lahouri; Wolfe, Robert E.

2011-01-01

57

Modeling urban heat islands in heterogeneous land surface and its correlation with impervious surface area by using night-time ASTER satellite data in highly urbanizing city, Delhi-India  

Science.gov (United States)

The present study is an assessment and identification of urban heat island (UHI) in the environment of one of the fastest urbanizing city of India, Delhi Metropolis, employing satellite image of ASTER and Landsat 7 ETM+ in the thermal infrared region 3-14 ?m. Temporal (2001 and 2005) ASTER datasets were used to analyze the spatial structure of the thermal urban environment subsequently urban heat island (UHI) in relation to the urban surface characteristics and land use/land cover (LULC). The study involves derivation of parameters governing the surface heat fluxes, constructing statistics of ASTER thermal infrared images along with validation through intensive in situ measurements. The average images reveal spatial and temporal variations of land surface temperature (LST) of night-time and distinct microclimatic patterns. Central Business District (CBD) of Delhi, (Connaught Place, a high density built up area), and commercial/industrial areas display heat islands condition with a temperature greater than 4 °C compared to the suburbs. The small increase in surface temperature at city level is mainly attributed to cumulative impact of human activities, changes in LULC pattern and vegetation density. In this study the methodology takes into account spatially-relative surface temperatures and impervious surface fraction value to measure surface UHI intensity between the urban land cover and rural surroundings. Both the spatial and temporal variation in surface temperature associated with impervious surface area (ISA) has been evaluated to assess the effect of urbanization on the local climate.

Mallick, Javed; Rahman, Atiqur; Singh, Chander Kumar

2013-08-01

58

Soil Composition  

Science.gov (United States)

Soil is essential for life on Earth. It is needed for food, air, clothing and so much more. Discussion topics include the terms 'soil', 'dirt', and 'sediment', factors affecting the formation of soils, soil horizons, and the twelve orders of soils. In a hands-on activity, students will collect soil samples from three different locations, use online resources to determine texture and particle makeup, and record their observations.

Fox, Chris; Pratte, John

59

Study of the Permeability of Foam Conditioned Soils with Laboratory Tests  

Directory of Open Access Journals (Sweden)

Full Text Available Problem statement: EPB tunneling requires that the excavated soil has a plastic and pulpy behavior to be able to apply a stabilizing pressure to the face, but it should also be impervious to counteract filtration forces that could develop ahead of the face. The evaluation of this parameter in granular soil, before and after conditioning, is therefore of key importance for a correct conditioning agents choice. Approach: A new laboratory procedure for testing the permeability of conditioned soil with foam has been proposed. The tests have been carried out at different hydraulic loads, chosen to be 0.1 bars and 1 bar. Results: The proposed procedure has been applied to determine the behavior of differently conditioned granular soils: a fluvial sand and a pozzolanic soil and has shown that an increasing of the FIR induces a relative increase in the time required by water to pass through a standard sample, emphasizing, in this way, the effectiveness of the conditioning on impermeability of the soil. Conclusion: The tests have shown the laboratory procedure adequately captures the behavior of the conditioned soil. Further, the proposed test may also be used as an index for the preliminary definition of the quality of the soil conditioning and suitability for EPB tunneling.

Luca Borio

2010-01-01

60

Mediterranean soils  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Mediterranean soils are soils which form under a Mediterranean climate. They are variously called Terra Rossa (on hard limestone) and Red Mediterranean Soils. Not all soils in a Mediterranean environment are, however, qualified as such because normal pedogenetic development may be hampered by erosion (rejuvenation of the profile), lack of time, lack of water or unfavorable parent material characteristics.

Verheyen, Willy; La Rosa, Diego

2005-01-01

 
 
 
 
61

Soil: Threats  

Sep 1, 2005 ... Climate change is likely to modify the key soil processes that ... In turn this affects \\soil structure, water regimes, and plant growth. ... Common soil contaminants \\include heavy metals, hydrocarbons, biological pathogens and substances ... the \\development of robust indicators and soil management guidelines ...

62

State Soils  

Science.gov (United States)

Developed by the US Department of Agriculture\\'s Soil Survey Division (SSD), this website describes state soils and their significance. All states have chosen a state soil, which share the same level of distinction as state flowers or birds. Information includes a photo of each official soil, a description of major characteristics and formation, and a map showing the coverage of the soil within the state. There are also links to additional information about that soil series, including more specific characteristics, other locations, related soil types, and more.

2007-02-14

63

Extraction and analysis of impervious surfaces based on a spectral un-mixing method using Pearl River Delta of China Landsat TM/ETM+ imagery from 1998 to 2008.  

Science.gov (United States)

Impervious surface area (ISA) is considered as an indicator of environment change and is regarded as an important input parameter for hydrological cycle simulation, water management and area pollution assessment. The Pearl River Delta (PRD), the 3rd most important economic district of China, is chosen in this paper to extract the ISA information based on Landsat images of 1998, 2003 and 2008 by using a linear spectral un-mixing method and to monitor impervious surface change by analyzing the multi-temporal Landsat-derived fractional impervious surface. Results of this study were as follows: (1) the area of ISA in the PRD increased 79.09% from 1998 to 2003 and 26.88% from 2003 to 2008 separately; (2) the spatial distribution of ISA was described according to the 1998/2003 percentage respectively. Most of middle and high percentage ISA was located in northwestern and southeastern of the whole delta, and middle percentage ISA was mainly located in the city interior, high percentage ISA was mainly located in the suburban around the city accordingly; (3) the expanding direction and trend of high percentage ISA was discussed in order to understand the change of urban in this delta; High percentage ISA moved from inner city to edge of urban area during 1998-2003 and moved to the suburban area that far from the urban area mixed with jumpily and gradually during 2003-2008. According to the discussion of high percentage ISA spatial expanded direction, it could be found out that high percentage ISA moved outward from the centre line of Pearl River of the whole delta while a high ISA percentage in both shores of the Pearl River Estuary moved toward the Pearl River; (4) combining the change of ISA with social conditions, the driving relationship was analyzed in detail. It was evident that ISA percentage change had a deep relationship with the economic development of this region in the past ten years. Contemporaneous major sport events (16th Asia Games of Guangzhou, 26th Summer Universidad of Shenzhen) and the government policies also promoted the development of the ISA. Meanwhile, topographical features like the National Nature Reserve of China restricted and affected the expansion of the ISA. Above all, this paper attempted to extract ISA in a major region of the PRD; the temporal and spatial analyses to PRD ISA demonstrated the drastic changes in developed areas of China. These results were important and valuable for land use management, ecological protection and policy establishment. PMID:22438741

Deng, Yingbin; Fan, Fenglei; Chen, Renrong

2012-01-01

64

Extraction and Analysis of Impervious Surfaces Based on a Spectral Un-Mixing Method Using Pearl River Delta of China Landsat TM/ETM+ Imagery from 1998 to 2008  

Directory of Open Access Journals (Sweden)

Full Text Available Impervious surface area (ISA is considered as an indicator of environment change and is regarded as an important input parameter for hydrological cycle simulation, water management and area pollution assessment. The Pearl River Delta (PRD, the 3rd most important economic district of China, is chosen in this paper to extract the ISA information based on Landsat images of 1998, 2003 and 2008 by using a linear spectral un-mixing method and to monitor impervious surface change by analyzing the multi-temporal Landsat-derived fractional impervious surface. Results of this study were as follows: (1 the area of ISA in the PRD increased 79.09% from 1998 to 2003 and 26.88% from 2003 to 2008 separately; (2 the spatial distribution of ISA was described according to the 1998/2003 percentage respectively. Most of middle and high percentage ISA was located in northwestern and southeastern of the whole delta, and middle percentage ISA was mainly located in the city interior, high percentage ISA was mainly located in the suburban around the city accordingly; (3 the expanding direction and trend of high percentage ISA was discussed in order to understand the change of urban in this delta; High percentage ISA moved from inner city to edge of urban area during 1998–2003 and moved to the suburban area that far from the urban area mixed with jumpily and gradually during 2003–2008. According to the discussion of high percentage ISA spatial expanded direction, it could be found out that high percentage ISA moved outward from the centre line of Pearl River of the whole delta while a high ISA percentage in both shores of the Pearl River Estuary moved toward the Pearl River; (4 combining the change of ISA with social conditions, the driving relationship was analyzed in detail. It was evident that ISA percentage change had a deep relationship with the economic development of this region in the past ten years. Contemporaneous major sport events (16th Asia Games of Guangzhou, 26th Summer Universidad of Shenzhen and the government policies also promoted the development of the ISA. Meanwhile, topographical features like the National Nature Reserve of China restricted and affected the expansion of the ISA. Above all, this paper attempted to extract ISA in a major region of the PRD; the temporal and spatial analyses to PRD ISA demonstrated the drastic changes in developed areas of China. These results were important and valuable for land use management, ecological protection and policy establishment.

Renrong Chen

2012-02-01

65

Solarization soil  

International Nuclear Information System (INIS)

Solar energy could be used in pest control, in soil sterilization technology. The technique consists of covering humid soils by plastic films steadily fixed to the soil. Timing must be in summer during 4-8 weeks, where soil temperature increases to degrees high enough to control pests or to produce biological and chemical changes. The technique could be applied on many pests soil, mainly fungi, bacteria, nematods, weeds and pest insects. The technique could be used in greenhouses as well as in plastic film covers or in orchards where plastic films present double benefits: soil sterilization and production of black mulch. Mechanism of soil solarization is explained. Results show that soil solarization can be used in pest control after fruit crops cultivation and could be a method for an integrated pest control. 9 refs

66

Soil Erosion  

Digital Repository Infrastructure Vision for European Research (DRIVER)

One element of the CIVCAL project Web-based resources containing images, tables, texts and associated data of the Soil Erosion. The word "erosion" is derived from the Latin "erosio", meaning to "to gnaw away". In general terms soil erosion implies the physical removal of topsoil by various agents, including rain, water flowing over and through the soil profile, wind, ice or gravitational pull. This part of the CIVCAL project introduces the processes and control of soil erosion, includi...

Kumaraswamy, Mohan

2002-01-01

67

Brown ground: a soil carbon analogue for the green world hypothesis?  

Science.gov (United States)

For many decades, ecologists have asked what prevents herbivores from consuming most of the plant biomass in terrestrial ecosystems, or "Why is the world green?" Here I ask the analogous question for detritivores: what prevents them from degrading most of the organic material in soils, or "Why is the ground brown?" For fresh plant detritus, constraints on decomposition closely parallel constraints on herbivory: both herbivore and decomposer populations may be controlled by plant tissue chemistry from the bottom up and predators from the top down. However, the majority of soil carbon is not plant litter but carbon that has been consumed by detritivores and reprocessed into humic compounds with complex and random chemical structures. This carbon persists mainly because the chemical properties of humic compounds and interactions with soil minerals constrain decomposition by extracellular enzymes in soil. Other constraints on decomposers, such as nutrient limitation of enzyme production and competition with opportunistic microbes, also contribute to brown ground. Ultimately, the oldest soil carbon persists via transformation into complex molecules that are impervious to enzymatic attack and effectively decoupled from processing by the soil food web. PMID:16671007

Allison, Steven D

2006-05-01

68

Comparing Soils  

Science.gov (United States)

Students compare soils sampled from different environments and describe their color, texture, and composition. Samples of different soils are mixed with water in small vials, and water soil profiles are compared for difference in particle size and organic content. Students are instructed to create their own inquiry investigation using soil and pea or bean seeds. This activity is supported by a textbook chapter, Soil: the Living Skin of the Earth, part of the unit, Losing Biodiversity, in Global Systems Science (GSS), an interdisciplinary course for high school students that emphasizes how scientists from a wide variety of fields work together to understand significant problems of global impact.

69

Creeping soil  

Science.gov (United States)

Soil creep is the most widespread and perhaps the least understood process of erosion on soil-mantled hillslopes. Soil is slowly “stirred” by burrowing creatures, and particles are displaced in wetting-drying cycles. These actions can cause downslope creep by processes analogous to particle diffusion. Other possible transport mechanisms include shear and viscous-like creep, such that precise characterization of the entire process appears to require the tracing of labeled soil grains. Here we use natural quartz grains in a mature soil to determine grain movements from the time elapsed since each grain last visited the ground surface, measured by single-grain optical dating. Downslope flux is calculated from soil production by rock weathering at the soil base, measured with in situ produced cosmogenic nuclide concentrations (10Be and 26Al). Results show that grains throughout the soil profile repeatedly visit the surface, and give the first quantitative characterization of grain-scale transport processes within creeping soil. These unique field data are interpreted with a Monte Carlo simulation to suggest that soil creep involves independent movements of mineral grains throughout the soil body and that grains are reburied or eroded by overland flow upon reaching the surface.

Heimsath, Arjun M.; Chappell, John; Spooner, Nigel A.; Questiaux, Danièle G.

2002-02-01

70

Development and substantiation of the structure of a masonry dam havinga soil cement membrane and designated for the climate of the far north of russia ?????????? ? ??????????? ??????????? ???????? ??????? ? ????????????????????? ??????? ??? ??????? ???????? ??????  

Directory of Open Access Journals (Sweden)

Full Text Available The Far North of Russia has a strong power generation potential. Future hydraulic power engineering projects may include construction of major power generating plants in south Yakutia. The core elements of the proposed projects will comprise dams about200 meters high.The authors substantiate construction of a masonry dam in severe climatic conditions of the Far Northern region of Russia. The structural solution represents a masonry dam having an impervious element, or a wide internal membrane, made of soil and cement concrete. This element is to protect the soil-free membrane from any thermal effects. The authors provide their analysis of the deflected mode of the dam, if its height is equal to 226 m. The findings have proven that the membrane made of soil and concrete cement will be in the state of compression. Therefore, the authors believe that the proposed design of the dam structure is reliable enough.?????????? ?????????? ? ??????? ????????????? ???????? ???????? ?????? ?????? ???????? ??????? ? ????????????????????? ????????? ? ???? ??????????? ???????? ?????? ?? ???????????????????. ??? ???????? ???????? ??????????? ????? ?? ????????????? ???????????. ????????? ?????????? ??????? ??????????-???????????????? ????????? ??????? ????? ??????????? ??????? 226 ?. ??? ????????, ??? ????????????????????? ????? ????? ?????????? ? ?????? ?????????. ??? ????????? ???????? ? ?????????? ??????? ????? ???????????.

Sainov Mikhail Petrovich

2013-03-01

71

Soil Temperatures  

Science.gov (United States)

For over a hundred years the Illinois State Water Survey, part of the Illinois Department of Natural Resources, "has documented quality data on a wide multitude of water and atmospheric variables". Within the main Web site is the Soil Temperatures page, which provides daily publication of maps based on data from various sites across the state. These include a 10am 4 inch bare soil temperature, daily maximum and minimum 4 inch bare soil temperature, 10am 4 inch soil temperature under sod, daily maximum and minimum 4 inch soil temperature under sod, and a daily maximum and minimum 8 inch soil temperature under sod map. The simple graphics display the particular variable along with what each of the nineteen stations recorded. Although location specific, the site gives those interested a helpful resource for easily retrieving the unique data provided.

2002-01-01

72

Soil suction  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Suction is pore water pressure in unsaturated soils and influences other soil characteristics. Suction measurements for 4 different soils (bentonite, stone flour, gray clay “sivica” and brown clay “flysch”) are presented. Measurements were performed on compacted and loose material at different water contents using 4 different methods: WP4 dewpoint potentiometer, filter paper, tenziometer and pressure plate apparatus. Additionally the water adsorption was determined for ...

Mac?ek, Matej

2006-01-01

73

Soils electroremediation  

International Nuclear Information System (INIS)

This paper presents data on decontamination experiments performed with soils contaminated by long-lived radioactive caesium isotopes. The contamination was formed about 30 years ago during an accident in the first nuclear power station in the former Czechoslovakia. Because of the large soil quantities that make excavation and storage of these soils in nuclear waste repositories inconvenient from economical and spatial point of view, various methods for in situ or ex situ remediation were sought and tested. For soil contamination by caesium, the time of contact of caesium with the soil is crucial because the caesium ions diffuse inside the crystalline structures of clay minerals where they are virtually irreversibly bound. For such materials, the efficiency of the classic 'soft' decontamination methods, such as leaching, phytoremediation etc., is rather low. Electrochemical decontamination was proposed as the decontamination technique for ex situ application. The method is based on electrolysis at a relatively high current density in a suitable electrolyte. The soil is kept in suspension close to the anode, and owing to the high acidity together with both the high temperature and ion flux, the soil structures are opened or partially disrupted and caesium ions are released. The ions can be separated from the solution, e.g., by using selective ion exchangers. The experimental electrolytic cell was designed for the treatment of thin soil layers containing about 3 g of thein soil layers containing about 3 g of the soil and about 100 mL of electrolyte. The influence of various system parameters, such as electrolyte composition, current-voltage, temperature, and time, on the decontamination efficiency was examined. In the most efficient configuration, a 99+% decontamination level was achieved. For the next step, a bench-scale apparatus was designed that should allow treatment of batches of up to 0.5 kg of soil in one step. (author)

74

Soil: Functions  

Mar 15, 2005 ... It helps clean the water we drink and the air that we breath - for free! ... surface \\and ground waters, above-ground habitats, and human activities. ... Threats to \\soil and soil quality endanger the sustainability and protection of ...

75

Bioremediation of soils contaminated with polycyclic aromatic hydrocarbons  

International Nuclear Information System (INIS)

The Iron Park Superfund site, North Billerica, Massachusetts, is located within a 553 acre operating industrial complex and railyard located approximately 20 miles northwest of Boston. Fifteen acres of this site are designated as the Wastewater Lagoon Area containing lagoons and materials previously dredged from those lagoons. The U.S. Environmental Protection Agency (EPA) placed the Iron Horse Park facility on its National Priorities List in 1984, and a Remedial Investigation (RI) for the site as a whole began n 1985. In September 1988, responding to the presence of these site contaminants, the EPA issued the first Superfund Record of Decision (ROD) in EPA Region I that specified bioremediation as the remedial technology. Specifically, the EPA stipulated biological land treatment cell with an impervious lower liner. In this form of biotreatment, sludges and contaminated soil are placed in the cell in lifts (i.e. layers approximately one foot thick) and the lifts are frequently aerated by tilling while nutrients are applied at optimal levels to stimulate the degradation of organic contaminants by indigenous microorganisms. In its Administrative Order (September 1989), the EPA stipulated cleanup goals to be achieved, and required that a Predesign Evaluation be initiated to ascertain which soil/sludge piles would require treatment. The design and execution of this remediation-focused site evaluation by ENSR forms the subject of this paper

76

SOIL BIOLOGY AND ECOLOGY  

Science.gov (United States)

The term "Soil Biology", the study of organism groups living in soil, (plants, lichens, algae, moss, bacteria, fungi, protozoa, nematodes, and arthropods), predates "Soil Ecology", the study of interactions between soil organisms as mediated by the soil physical environment. oil ...

77

Helping People Understand Soils  

Science.gov (United States)

This slide show provides an introduction to soil and soil science. Topics include the functions of soil and its role in the ecosystem, soil management, important properties of soil, and factors that influence the location and types of soils that form. There is also information on soil surveys, possible negative impacts to soil, the soils taxonomy system, and how soil science meshes with other disciplines.

2010-11-24

78

Clay slurry and engineered soils as containment technologies for remediation of contaminated sites  

Energy Technology Data Exchange (ETDEWEB)

Clay Slurry and Engineered Soils are containment technologies for remediation of waste disposal sites where leaching, groundwater plumes and surface runoff of contaminants are serious ecological hazards to adjacent environments. This technology is a patent-pending process which involves the use of conditioned clay materials mixed with sand and water to form a readily pourable suspension, a clay slurry, which is either placed into a trench barrier system or allowed to de-water to create Engineered Soils. The Engineered Soil forms a layer impervious to water and air, therefore by inhibiting both water and oxygen from penetrating through the soil the material. This material can be installed in layers and as a vertical barrier to create a surface barrier containment system. The clay percentage in the clay slurry and Engineered Soils varies depending on site characteristics and desired performance standards. For example Engineered Soils with 1-2% of clay (dry wt.) had a hydraulic conductivity (K) of 10{sup -8} to 10{sup -1} cm/sec. Tests of tailing materials from a kyanite and pyrite mine showed that the clay slurry was effective not only in reducing the permeability of the treated tailings, but also in decreasing their acidity due to the inherent alkalinity of the clay. The untreated tailings had pH values in the range of 2.4 - 3.1; whereas, the effluent from clay and tailings mixtures had pH values in a slightly alkaline range (7.7-7.9). Pug-mills and high volume slurry pumps can be readily adapted for use in constructing and placing caps and creating Engineered Soils. Moreover, material on site or from a local sand supply can be used to create clay slurries and engineered soils. Clay materials used in cap construction are likewise readily available commercially. As a result, the clay slurry system is very cost effective compared to other capping systems, including the commonly used High Density Polyethylene (HDPE) liner systems.

Williams, J.R. [Reclamation Technology, Inc., Athens, GA (United States); Dudka, S.; Miller, W.P. [Univ. of Georgia, Athens, GA (United States); Johnson, D.O. [Argonne National Lab., IL (United States)

1997-12-31

79

Characterization of Selenium Pollution in the Western United States by Coupling Soil Moisture with Geochemical Transport  

Science.gov (United States)

Due to the arid conditions of the Western United States, selenium released from sandstone and shale hillslopes is transported by overland runoff and is shown to cause fish and aquatic bird death and reproductive failure. Precipitation in contact with exposed seleniferous soils, carry dissolved and particulate forms of selenium in runoff and groundwater to the valley floor to be redistributed throughout the hillslope and alluvial fan. Impervious clay soils and the arid climate impede the flushing of selenium below the groundwater table so that selenium is continually cycled in the alluvial fan. A physically based model that couples hydrologic land surface interactions and geochemical transport based on soil moisture was developed to characterize the loading, transport, and distribution of selenium. The soil moisture distribution and overland flow patterns determined by the hydrologic model for the watershed are factors that control soil chemical movement and transformation. The main geochemical and physical transport mechanisms of selenite and selenate, dissolution from soil, speciation, adsorption, advection, and mass transfer from pore water to overland form, are characterized as functions of surface flow and the soil moisture of the fifteen centimeter deep soil layer for each model grid. The movement of overland flow within each grid is routed to the outlet of the watershed. Flow patterns and measured selenium concentrations at two sites; the Panoche/ Silver Creek watershed in Central California, and the Leach Creek watershed in Colorado, are compared to model results. Selenium pollution characterization at a watershed scale will add to the understanding of the cycling of selenium within and across watersheds and aid in the mitigation of selenium pollution.

Zhao, M.; Liang, X.; Guo, J.

2004-12-01

80

Soil Association  

Science.gov (United States)

Since its inception over a half century ago, the Soil Association has "been working to raise awareness about the positive health and environmental benefits of organic food and farming and supporting farmers in producing natural food consumers can trust." Originally formed by a coalition of inspired scientists, nutritionists, and farmers, the Soil Association is now the leading organic farming and food certification and campaigning organization in the United Kingdom. Although primarily geared towards citizens of the United Kingdom, the Association website merits a perusal from anyone interested in the organic food movement. Site features include a large online library containing hundreds of documents listed under such categories as Animal Welfare, Biodiversity, Horticulture, Pesticides, and Education; profiles of many organic farms in the UK; a classified ads page with information about employment opportunities and items for sale; information about the Soil Association's standards for organic production and processing; and more.

 
 
 
 
81

Soil shrinkage characteristics in swelling soils  

International Nuclear Information System (INIS)

The objectives of this presentation are to understand soil swelling and shrinkage mechanisms, and the development of desiccation cracks, to distinguish between soils having different magnitude of swelling, as well as the consequences on soil structural behaviour, to know methods to characterize soil swell/shrink potential and to construct soil shrinkage curves, and derive shrinkage indices, as well to apply them to assess soil management effects

82

Soils - Part 9: Fundamentals of Soil Testing  

Science.gov (United States)

The major emphasis in this lesson is soil testing and understanding the procedures needed to take a representative soil sample. You will understand the term variability, how it affects soil tests, and how a soil test is developed.[This lesson, as well as the other nine lessons in the Soils series, is taken from the "Soils Home Study Course," published in 1999 by the University of Nebraska Cooperative Extension.

83

Soil-Net.com  

Science.gov (United States)

Soil-Net.com provides teachers and students ages 5 through 16 (UK Key Stages 1-4) with extensive curriculum-based information about soil, one of our three major natural resources alongside air and water. The site helps users learn about what soil is, the teeming life in soil, the many environmental threats facing soils, and current developments affecting soils-related policymaking and soil science. Soil-Net.com was developed by the National Soil Resources Institute (NSRI) of Cranfield University, UK, the leading institution of soil science and soil-related research in England and Wales.

84

Soil Temperature Protocol  

Science.gov (United States)

The purpose of this resource is to measure near-surface soil temperatures. Students measure soil temperatures at 5 cm and 10 cm depths using a soil thermometer. Students will be able to perform a soil thermometer calibration, carry out soil temperature measurements accurately and precisely and record and report soil temperature data. Students will be able to relate soil temperature measurements to the physical and chemical properties of soil.

The GLOBE Program, University Corporation for Atmospheric Research (UCAR)

2003-08-01

85

Soils - Part 2: Physical Properties of Soil and Soil Water  

Science.gov (United States)

This lesson will help you understand the major components of the physical properties of soil. You will learn such terms as texture, aggregation, soil structure, bulk density, and porosity as it relates to soils. You will learn how soil holds and transmits water and cultural practices that enhance or degrade physical properties of the soil.[This lesson, as well as the other nine lessons in the Soils series, is taken from the "Soils Home Study Course," published in 1999 by the University of Nebraska Cooperative Extension.

86

Soil microbiology  

International Nuclear Information System (INIS)

The major areas of soil microbiological and biochemical research which have involved both stable and radioactive isotopes are summarized. These include microbial decomposition of naturally occurring materials, microbial biomass, interactions of plants and microbes, denitrification, mineralization and immobilization of nitrogen and biological nitrogen fixation. (U.K.)

87

Estimation of impervious-area washoff parameters.  

Science.gov (United States)

In recent years many models have been developed which simulate the quality of rainfall runoff from urban areas. Common to many of these models is the use of an exponential washoff equation. Application of these techniques to a small urban watershed in S Florida demonstrated considerable variability in the optimized parameter values among different storms and among different constituents. -from Author

Alley, W. M.

1981-01-01

88

Laboratory Assessment of Water Flow Simulator for Porous Parking Lots Reservoir and Soil Layers  

Directory of Open Access Journals (Sweden)

Full Text Available Porous parking lots were implemented to fill the scarcity and strengthen the sustainable development of impervious surfaces in Malaysia to reduce surface runoff. The new methodology proposed enable simulation of reservoir course at stipulated air voids despite details study on water levels and infiltration of porous parking lots system. A uniformly graded choker and reservoir stones functioned as reservoir structure for temporary storm water detention. A specially fabricated water flow simulator allows laboratory simulation of the porous parking lot system. The ability to simulate 1.24 to 59.89 cm h-1 rainfall intensities enable laboratory testing to verify water level and discharge time correlations with different soil infiltration rate at various rainfall intensities. The laboratory tests of vertical infiltration were conducted under conditions of saturated soils. At 59.89 cm h-1 simulated rainfall intensity, the highest water level recorded inside the water flow simulators body without reservoir course is 55 cm from the surface of 0.254 cm h-1 soil infiltration rate. A total of 80.5 h duration was required to completely discharge the stored water between large aggregate particles due to low soil infiltration rate. Utilizing the same laterite soil as bottom layer, the depth increased by approximately 60% after installation of reservoir course with approximately 40% air voids. Over a 60 min duration, the soil with coefficient of permeability equaled to 25.4 cm h-1 had recorded water level 20 cm in height and completely dried within 32.2 min only.

Zul Fahmi Mohamed Jaafar

2011-01-01

89

Soil sampling  

International Nuclear Information System (INIS)

This study attempts to survey the problems associated with techniques and strategies of soil sampling. Keeping in mind the well defined objectives of a sampling campaign, the aim was to highlight the most important aspect of representativeness of samples as a function of the available resources. Particular emphasis was given to the techniques and particularly to a description of the many types of samplers which are in use. The procedures and techniques employed during the investigations following the Seveso accident are described. (orig.)

90

Soil Nailing  

Digital Repository Infrastructure Vision for European Research (DRIVER)

One element of the CIVCAL project Web-based resources containing images, tables, texts and associated data on the construction of the Soil Nailing. Prior to the establishment of the Geotechnical Engineering Office (GEO) in 1977, there was very limited geotechnical control over the slope formation and virtually no monitoring over the existing slopes in Hong Kong. Since then, the government launched a major investigation and assessment project to catalogue all the slopes in the territory...

Kumaraswamy, Mohan

2002-01-01

91

USDA Soil Survey Division  

Science.gov (United States)

The goal of the US Department of Agriculture (USDA) Soil Survey Division (SSD) is to assess the world\\'s soil resources. This site provides soil surveys and maps by state, which indicate the agriculture and climate, descriptions of soil types, soil uses, and suitability for land use. Contact information for local and state soil scientists are given. Users can also access soil characterization information and classification data tables.

2007-02-18

92

Soils; 1 : 500 000  

International Nuclear Information System (INIS)

Soil associations forming map units express representation of soil units in the territory of Slovakia. They present the dominance of the soil units in associations and some other elements, above all the soil-forming substrates and in abbreviated classification also the extreme soil textures (light to heavy). Genetically related units are classified into groups of soil associations. The map was made by generalisation of cartographic materials of all soil investigations and mapping made since 1960 to the present day. (authors)

93

Soils - Part 3: Soil Organic Matter  

Science.gov (United States)

In this lesson, you will learn such terms as organic, soil organic matter, nutrient, decomposition, humus, compost, and soil structure. In addition, you will be able to predict the effect of land uses on soil organic matter including the effects of different types of vegetation.[This lesson, as well as the other nine lessons in the Soils series, is taken from the "Soils Home Study Course," published in 1999 by the University of Nebraska Cooperative Extension.

94

Soil Stabilization Using Lime  

Directory of Open Access Journals (Sweden)

Full Text Available Soil stabilization can be explained as the alteration of the soil properties by chemical or physical means in order to enhance the engineering quality of the soil . The main objectives of the soil stabilization is to increase the bearing capacity of the soil ,its resistance to weathering process and soil permeability. The long-term performance of any construction project depends on the soundness of the underlying soils. Unstable soils can create significant problems for pavements or structures, Therefore soil stabilization techniques are necessary to ensure the good stability of soil so that it can successfully sustain the load of the superstructure especially in case of soil which are highly active, also it saves a lot of time and millions of money when compared to the method of cutting out and replacing the unstable soil. This paper deals with the complete analysis of the improvement of soil properties and its stabilization using lime.

ANKIT SINGH NEGI

2013-02-01

95

Soil Core Sampling  

Science.gov (United States)

Students learn about one method used in environmental site assessments. They practice soil sampling by creating soil cores, studying soil profiles and characterizing soil profiles in borehole logs. They use their analysis to make predictions about what is going on in the soil and what it might mean to an engineer developing the area.

Integrated Teaching And Learning Program

96

In-situ determination of directional conductivities of soil  

International Nuclear Information System (INIS)

Hydraulic conductivity K is a macroscopic parameter which depends on the properties of both the fluid as well as the porous matrix. Stratified soils are usually anisotropic in nature. In most soils, the water transmitting capacity in the horizontal direction is observed to be higher than the vertical conductivity. However, in many soils (e.g., loess), vertical joints, root holes and animal burrows make the vertical conductivity higher than the horizontal. Accurate estimations of the horizontal and the vertical conductivities of a soil medium in its natural water-saturated state is of considerable importance in obtaining rational solutions to drainage and other groundwater flow problems. This lecture will be mainly concerned with the development of a suitable auger hole seepage theory for the confined situation. The depth to the impervious layer, partial penetration of the auger hole, level of water in the auger hole, and confining pressure of the aquifer are taken, all distances being measured from the confining stratum. The saturated hydraulic conductivities of the soil in the horizontal and vertical directions are taken. Because of axial symmetry, we consider only one half of the flow domain for analysis located towards the right of the vertical axis passing through the origin O. For convenience, we take the z axis to be positive vertically downward and r axis to be positive towards the right. Further, in the analysis to follow, we assume the flow to be steady, the drawdown near the vicinity of the hole during one experimental cycle to be negligible the aquifer material and water to be incompressible and the principal directions of anisotropy of the aquifer to coincide with the horizontal and vertical directions, respectively. In order to obtain solution to the problem, the hydraulic head functions must be determined such that the governing equations. If the entire computation is repeated (again by taking M = N = 100) by neglecting the confining pressure, i.e. t = 0, the K value now turns out to be 2.90 m/day. It can be observed that this value differs considerably from that of 0.96 m/day obtained by considering the confining pressure of the aquifer. As can be seen, an error of about 200% occurs for this flow situation due to neglect of this confining water head

97

Does Soil Disturbance Affect Soil Phosphorus Fractions?  

Directory of Open Access Journals (Sweden)

Full Text Available Increased turnover of organic matter as a result of soil disturbance (e.g. by soil tillage is described in principle, but the direct influence of soil disturbance on soil P turnover especially for organic farming systems has not been sufficiently proven. The objective of the study was to evaluate the short term effect of soil disturbance on different soil P fractions in a soil shaking experiment. Four soils were incubated for 10 days in the dark with three different disturbance treatments: 1 no disturbance, 2 overhead shaking for 2 h at the beginning of the experiment and 3 continuous overhead shaking at 5 r. p. m. The four investigated soils were: 1 a silty loam soil with long term bio-compost application and 2 the corresponding soil without bio-compost application, 3 a long-term organically managed clay loam soil and 4 a clay loam soil with long time application of pig manure, all not and from Baden-Württemberg, Germany. We determined NaHCO3-, NaOH- and H2SO4-extractable inorganic and organic P fractions (Pi and Po, resp. in a sequential extraction. Furthermore, the potentially plant available P as Calcium-acetate-lactate-extractable P (CAL-P and P extractable by electro-ultra-filtration (EUF-P, and aqua regia extractable total P (PT were determined. Furthermore, we determined microbial biomass carbon (MBC, nitrogen (MBN and phosphorus (MBP, and acid phosphatase activity in soil. The organically managed soil had the highest PT contents (1300 mg·kg-1. The soil with pig manure application had the smallest potentially labile P fractions (NaHCO3-Pi and -Po and NaOH-Pi. The ecologically managed soil had the biggest organic P fractions (114 mg·kg-1 NaHCO3-Po and 463 mg·kg-1 NaOH-Po, but, this soil was the lowest in CAL-P (5 mg·kg-1. Short term soil disturbance had effects on labile organic P fractions of two of the four analyzed soils, but inorganic P was rather unaffected. In the compost amended COMP(+ soil, there was an incorporation of P from the less available NaOH-P fractions into the more available NaHCO3-Po fraction. However, if taking all investigated soils and treatments into account, the effects of soil disturbance were limited and not consistent.

Yonathan D. Redel

2013-10-01

98

Trees, Soil and Water  

Science.gov (United States)

Trees, soil and water: Journey to Forever - health care for mountains, trees for deserts, trees for people, forest, forestry, deforestation, erosion, soil conservation, water conservation, desertification.

Addison, Keith

2010-01-01

99

Soils: Photo Gallery  

Science.gov (United States)

An interesting page from the US Department of Agriculture's Natural Resources Conservation Service (NRCS) Web site is entitled Soils: Photo Gallery. Visitors can choose from State Soils, Soil Images and Landscapes, Principles and Techniques, and the NRCS Photo Gallery. The interesting state soils link contains individual pages that present descriptions and photos of that state's official soil. For example, Wisconsin's state soil Antigo is described as the most extensive soil in the state and is very productive for corn, small grain, and hay. A picture of the soil as part of a landscape, a layered profile, and a graphic of where it's predominantly located is provided.

2008-09-18

100

Phenols in rice soils  

Energy Technology Data Exchange (ETDEWEB)

In a laboratory study on the distribution of phenols in rice soils, a humus-rich acid sulfate soil liberated more alkali-extractable phenols than an alluvial soil under both flooded and nonflooded conditions. Nonflooded conditions appeared to favor the release of phenols from the acid sulfate soil whereas in the alluvial soil no difference was apparent under the two water regimes. The addition of calcium carbonate to the acid sulfate soil further increased the production of phenols. Analysis of the solvent extract of the soils by thin-layer chromatography showed that both the soils contained vanillic acid and two unidentified phenols.

Rao, A.V.; Rajaram, K.P.; Siddaramappa, R.; Sethunathan, N.

1975-01-01

 
 
 
 
101

Soil structure interaction and soil models  

Science.gov (United States)

Soil-structure interaction effects can significantly alter the computed seismic behavior of a structure. The accurate characterization of the nonlinear soil behavior is important in considering seismic amplification and attenuation. Soil models, fitting of parameters, and comparison of results are discussed. Linear and nonlinear example data are compared.

Ferritto, J. M.

1982-05-01

102

Soil organic matter mineralization in frozen soils  

Science.gov (United States)

Boreal forest soils are frozen for a large part of the year and soil organic matter mineralization during this period has been shown to significantly influence the C balance of boreal forest ecosystems. Mineralization proceeds through heterotrophic microbial activity, but the understanding of the environmental controls regulating soil organic matter mineralization under frozen conditions is poor. Through a series of investigations we have addressed this issue in order to elucidate to what extent a range of environmental factors control mineralization processes in frozen soils and also the microbial communities potential to oxidize organic substrates and grow under such conditions. The unfrozen water content in the frozen soils was shown to be an integral control on the temperature response of biogenic CO2 production across the freezing point of bulk soil water. We found that osmotic potential was an important contributor to the total water potential and, hence, the unfrozen water content of frozen soil. From being low and negligible in an unfrozen soil, the osmotic potential was found to contribute up to 70% of the total water potential in frozen soil, greatly influencing the volume of liquid water. The specific factors of how soil organic matter composition affected the unfrozen water content and CO2 production of frozen soil were studied by CP-MAS NMR. We concluded that abundance of aromatics and recalcitrant compounds showed a significant positive correlation with unfrozen water content and these were also the major soil organic fractions that similarly correlated with the microbial CO2 production of the frozen soils. Thus, the hierarchy of environmental factors controlling SOM mineralization changes as soils freeze and environmental controls elucidated from studies of unfrozen systems can not be added on frozen conditions. We have also investigated the potential activity of soil microbial communities under frozen conditions in order to elucidate temperature limitations on soil organic matter mineralization. The carbon mineralization was found to proceed down to -4°C and the soil microbial communities were growing at this temperature. At -9°C, the carbon mineralization was insignificant. 13C NMR revealed that the soil microorganisms were able to produce ethylene glycol (anti-freeze medium) under frozen conditions (-4°C). The production of ethylene glycol coincided with an increase in CO2 production that took place after a lag-phase of ca. 41 days. 13C NMR also confirmed that soil microbial anabolic processes continued under frozen conditions. At -4°C, 23% of the used substrate was respired as CO2 and 77% were converted and assimilated by the organisms as e.g. lipids and polysaccharides. This is contradicting to earlier studies that suggest that mainly processes yielding CO2 occurs in soils at <0°C.

Harrysson Drotz, S.; Sparrman, T.; Schleucher, J.; Nilsson, M.; Öquist, M. G.

2009-12-01

103

Soil Strategy for England  

soil, as well as existing advice, quality protocols and standards for the use of \\materials ... out since 1978 through the Countryside Survey, which includes \\analysis of soils. ..... This will look at a range of factors from changes in soil pH to \\erosion .... We need better evidence on trends in soil carbon concentrations and \\on.

104

Soils as Construction Materials  

Science.gov (United States)

This geotechnical project will introduce you with the concept of using soils as construction materials.This project involves characterizing soils using various laboratory analyses and applying the Unified Soil Classification System in naming the soil. Keywords: Geotechnical, Mass Wetness, Grain Size Analysis, Atterberg Limits

Kowalewski, Douglas

105

Soil water management  

International Nuclear Information System (INIS)

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.)

106

Soil Properties and Geomorphology  

Science.gov (United States)

To prepare for this exercise, the students have been lectured on soil formation and on a field trip, described a simple soil within loess. Here, the students use data collected from a chronosequence to compare the relative age and amount of soil formation on a series of fluvial terraces. The students are to insert the data into a graphic program and generate specific graphs of soil properties. The students then interpret the amount of soil formation compared to the relative age of the fluvial terraces. Finally, the students assess how the 5 soil forming factors (climate, organisms, relief, parent material, and time) influenced soil formation in this setting. Designed for a geomorphology course

Sweeney, Mark

107

Soil physical properties affecting soil erosion in tropical soils  

International Nuclear Information System (INIS)

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 detachment. Studies on necessary kinetic energy to detach one kilogram of sediments by raindrop impact have shown that the minimum energy is required for particles of 0.125 mm. Particles between 0.063 to 0.250 mm are the most vulnerable to detachment. This means that soils with high content of particles into vulnerable range, for example silty loam, loamy, fine sandy, and sandy loam are the most susceptible soils to detachment. Many aspects of soil behaviour in the field such as hydraulic conductivity water retention, soil crusting, soil compaction, and workability are influenced strongly by the primary particles. In tropical soils also a negative relation between structure stability and particles of silt, fine sand and very fine sand has been found, this is attributed to low cohesiveness of these particles. The ability of a structure to persist is known as its stability. There are two principal types of stability: the ability of the soil to retain its structure under the action of water, and the ability of the soil to retain its structure under the action of external mechanical stresses. (e.g. by wheels). Both types of stability are related with susceptibility to erosion

108

Remote Sensing of Agricultural Soils degradation: Studying Soil Losses, Soil Drying and Soil Quality Deterioration  

Science.gov (United States)

Remote Sensing of Agricultural Soils degradation: Studying Soil Losses, Soil Drying and Soil Quality Deterioration Remote sensing mapping of soil properties is instrumental for understanding the extents rates of agricultural land degradation. In our presentation there will be reviewed methods allowing the detection of soil losses, soil drying and soil quality deterioration utilizing passive and active sensors. The task is difficult since these processes involve sub-surface properties such as salination, water content, soil organic matter, nutrients and organic and inorganic contaminants. In recent studies a distinctive number of researchers in this field recommended the application of multi-sensor and multi-temporal approaches as well as methods integrating environmental information (topography, soil types and precipitation for example). These integrative approaches will be discussed during the conference.

Shoshany, Maxim

2014-05-01

109

ISRIC - World Soil Information  

Digital Repository Infrastructure Vision for European Research (DRIVER)

ISRICWorld Soil Information is an independent foundation, funded by the Netherlands Government with a mandate to increase knowledge of the land, its soils in particular, and to support the sustainable use of land resources; in short, to help people understand soils. Its aims are to -Inform and educate, through the World Soil Museum. -Maintain and disseminate data for the scientific community through the ICSU World Data Centre for Soils which is the custodian of global and regional datasets, ...

Dent, D. L.

2006-01-01

110

Soil hydraulic properties of Cuban soils  

International Nuclear Information System (INIS)

Because soil hydraulic properties are indispensable for determining soil water retention and soil water movement, their input for deterministic crop simulation models is essential. From these models is possible to access the effect of the weather changes, soil type or different irrigation schedules on crop yields. With these models, possibilities are provided to answer questions regarding virtual 'what happen if' experiments with a minimum of fieldwork. Nevertheless, determining soil hydraulic properties can be very difficult owing to unavailability of necessary equipment or the lack of personal with the proper knowledge for those tasks. These deficiencies are a real problem in developing countries, and even more so when there is not enough financial possibilities for research work. This paper briefly presents the way these properties have been accessed for Cuban soils, which methods have been used and the work now in progress. (author)

111

Mass Transport within Soils  

Energy Technology Data Exchange (ETDEWEB)

Contaminants in soil can impact human health and the environment through a complex web of interactions. Soils exist where the atmosphere, hydrosphere, geosphere, and biosphere converge. Soil is the thin outer zone of the earth's crust that supports rooted plants and is the product of climate and living organisms acting on rock. A true soil is a mixture of air, water, mineral, and organic components. The relative proportions of these components determine the value of the soil for agricultural and for other human uses. These proportions also determine, to a large extent, how a substance added to soil is transported and/or transformed within the soil (Spositio, 2004). In mass-balance models, soil compartments play a major role, functioning both as reservoirs and as the principal media for transport among air, vegetation, surface water, deeper soil, and ground water (Mackay, 2001). Quantifying the mass transport of chemicals within soil and between soil and atmosphere is important for understanding the role soil plays in controlling fate, transport, and exposure to multimedia pollutants. Soils are characteristically heterogeneous. A trench dug into soil typically reveals several horizontal layers having different colors and textures. As illustrated in Figure 1, these multiple layers are often divided into three major horizons: (1) the A horizon, which encompasses the root zone and contains a high concentration of organic matter; (2) the B horizon, which is unsaturated, lies below the roots of most plants, and contains a much lower organic carbon content; and (3) the C horizon, which is the unsaturated zone of weathered parent rock consisting of bedrock, alluvial material, glacial material, and/or soil of an earlier geological period. Below these three horizons lies the saturated zone - a zone that encompasses the area below ground surface in which all interconnected openings within the geologic media are completely filled with water. Similarly to the unsaturated zone with three major horizons, the saturated zone can be further divided into other zones based on hydraulic and geologic conditions. Wetland soils are a special and important class in which near-saturation conditions exist most of the time. When a contaminant is added to or formed in a soil column, there are several mechanisms by which it can be dispersed, transported out of the soil column to other parts of the environment, destroyed, or transformed into some other species. Thus, to evaluate or manage any contaminant introduced to the soil column, one must determine whether and how that substance will (1) remain or accumulate within the soil column, (2) be transported by dispersion or advection within the soil column, (3) be physically, chemically, or biologically transformed within the soil (i.e., by hydrolysis, oxidation, etc.), or (4) be transported out of the soil column to another part of the environment through a cross-media transfer (i.e., volatilization, runoff, ground water infiltration, etc.). These competing processes impact the fate of physical, chemical, or biological contaminants found in soils. In order to capture these mechanisms in mass transfer models, we must develop mass-transfer coefficients (MTCs) specific to soil layers. That is the goal of this chapter. The reader is referred to other chapters in this Handbook that address related transport processes, namely Chapter 13 on bioturbation, Chapter 15 on transport in near-surface geological formations, and Chapter 17 on soil resuspention. This chapter addresses the following issues: the nature of soil pollution, composition of soil, transport processes and transport parameters in soil, transformation processes in soil, mass-balance models, and MTCs in soils. We show that to address vertical heterogeneity in soils in is necessary to define a characteristic scaling depth and use this to establish process-based expressions for soil MTCs. The scaling depth in soil and the corresponding MTCs depend strongly on (1) the composition of the soil and physical state of the soil, (2) the chemical and p

McKone, Thomas E.

2009-03-01

112

Soil washing technology evaluation  

Energy Technology Data Exchange (ETDEWEB)

Environmental Restoration Engineering (ERE) continues to review innovative, efficient, and cost effective technologies for SRS soil and/or groundwater remediation. As part of this effort, this technical evaluation provides review and the latest information on the technology for SRS soil remediation. Additional technology evaluation reports will be issued periodically to update these reports. The purpose of this report is to review the soil washing technology and its potential application to SRS soil remediation. To assess whether the Soil Washing technology is a viable option for SRS soil remediation, it is necessary to review the technology/process, technology advantages/limitations, performance, applications, and cost analysis.

Suer, A.

1995-04-01

113

Soil washing technology evaluation  

International Nuclear Information System (INIS)

Environmental Restoration Engineering (ERE) continues to review innovative, efficient, and cost effective technologies for SRS soil and/or groundwater remediation. As part of this effort, this technical evaluation provides review and the latest information on the technology for SRS soil remediation. Additional technology evaluation reports will be issued periodically to update these reports. The purpose of this report is to review the soil washing technology and its potential application to SRS soil remediation. To assess whether the Soil Washing technology is a viable option for SRS soil remediation, it is necessary to review the technology/process, technology advantages/limitations, performance, applications, and cost analysis

114

Tillage effects on soil respiration in Swedish arable soils  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The amount of carbon (C) present in soil is greater than the sum of C present in terrestrial vegetation and the atmosphere combined. Small changes in soils can therefore affect atmospheric CO? levels and ultimately the global climate. Soil C is also one of the main soil properties involved in several soil functions critical for soil productivity. Mechanical disturbance of the soil, e.g. through tillage, can influence soil C and has been the focus...

Kainiemi, Veera

2014-01-01

115

Remote Sensing of Soil  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Remote sensing has shown a high potential in soil characteristics retrieving in the last three decades. Different methodologies have been proposed for the estimation of soil parameters, based on different remote sensing sensors and techniques (passive and active).

Mehrez Zribi; Nicolas Baghdadi; Michel Nolin

2011-01-01

116

Controlling soil erosion  

Sediment deposited in rivers can damage spawning grounds of fish and can kill \\... Soil organic matter also influences aggregate stability by its binding effect, \\which can ... Maintaining a high soil infiltration rate will reduce surface run-off.

117

CONSIDERATIONS ON URBAN SOILS  

Directory of Open Access Journals (Sweden)

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.

Radu Lacatusu

2005-10-01

118

Remediation of Contaminated Soils  

International Science & Technology Center (ISTC)

Development of Methods for Remediation of Soils with Increased Contents of Heavy Metals, Radionuclides and Improvement of Soils for Ecologically Clean Agricultural Production Systems Taking into Account the Population Health Indicators

119

iSOIL: Interactions between soil related sciences - Linking geophysics, soil science and digital soil mapping  

Science.gov (United States)

High-resolution soil property maps are one major prerequisite for the specific protection of soil functions and restoration of degraded soils as well as sustainable land use, water and environmental management. To generate such maps the combination of digital soil mapping approaches and remote as well as proximal soil sensing techniques is most promising. However, a feasible and reliable combination of these technologies for the investigation of large areas (e.g. catchments and landscapes) and the assessment of soil degradation threats is missing. Furthermore, there is insufficient dissemination of knowledge on digital soil mapping and proximal soil sensing in the scientific community, to relevant authorities as well as prospective users. As one consequence there is inadequate standardization of techniques. At the poster we present the EU collaborative project iSOIL within the 7th framework program of the European Commission. iSOIL focuses on improving fast and reliable mapping methods of soil properties, soil functions and soil degradation risks. This requires the improvement and integration of advanced soil sampling approaches, geophysical and spectroscopic measuring techniques, as well as pedometric and pedophysical approaches. The focus of the iSOIL project is to develop new and to improve existing strategies and innovative methods for generating accurate, high resolution soil property maps. At the same time the developments will reduce costs compared to traditional soil mapping. ISOIL tackles the challenges by the integration of three major components: (i)high resolution, non-destructive geophysical (e.g. Electromagnetic Induction EMI; Ground Penetrating Radar, GPR; magnetics, seismics) and spectroscopic (e.g., Near Surface Infrared, NIR) methods, (ii)Concepts of Digital Soil Mapping (DSM) and pedometrics as well as (iii)optimized soil sampling with respect to profound soil scientific and (geo)statistical strategies. A special focus of iSOIL lies on the sustainable dissemination of technologies and concepts developed in the projects through workshops for stakeholders and the publication of a handbook "Methods and Technologies for Mapping of Soil Properties, Function and Threat Risks". Besides, the CEN Workshop offers a new mechanism and approach to standardization. During the project we decided that the topic of the CEN Workshop should focus on a voluntary standardization of electromagnetic induction measurement to ensure that results can be evaluated and processed under uniform circumstances and can be comparable. At the poster we will also present the idea and the objectives of our CEN Workshop "Best Practice Approach for electromagnetic induction measurements of the near surface"and invite every interested person to participate.

Dietrich, Peter; Werban, Ulrike; Sauer, Uta

2010-05-01

120

Dielectric characterisation of soil.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The potential of dielectric measuring techniques for soil characterisation has not been fully explored. This is attributed to the complex and incomplete theory on dielectrics, as well as to the lack of sensors suited for practical applications.The theory on dielectric properties of soils is described, evaluated, and expanded. Colloidal polarisation of soil particles appears to be negligible. The polarisability of air bubbles in the soil matrix is made plausible. The Maxwell-Wagner effect is e...

Hilhorst, M. A.

1998-01-01

 
 
 
 
121

Iodine dynamics in soil  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The principal aim of this investigation was to understand the transformation and reaction kinetics of iodide and iodate added to soil in relation to soil properties. In addition, to integrate the data into a predictive model of iodide and iodate sorption kinetics parameterised by soil properties. Solid phase fractionation coupled with solution phase speciation (HPLC-ICPMS) was used to follow the assimilation of 129I- and 129IO3- spikes into ‘steady state’ soil microcosms. The ext...

Hassan Shetaya, Waleed Hares Abdou

2011-01-01

122

Neptunium in soils  

International Nuclear Information System (INIS)

A bibliography and compiled data are presented on neptunium isotopes in different soil types, especially 237Np. After surveying soil chemistry and sorption behaviour of a variety of rock types and soil types like loams, sands and clays, the mobility of neptunium is considered. (G.J.P.)

123

Soil indicators: Organic matter  

Mar 9, 2005 ... Contact us · Jobs · News · Site A-Z ... Organic matter enters soils from plant, \\animal or microbial ... of mineral-based soils, organic matter has an influence on \\its chemical, ... Altering soil pH; Assisting with a good structure for root growth ... \\chemicals and can buffer the release of pollutants into air or water.

124

Gravimetric Soil Moisture Protocols  

Science.gov (United States)

The purpose of this resource is to measure soil water content by mass. Students collect soil samples with a trowel or auger and weigh them, dry them, and then weigh them again. The soil water content is determined by calculating the difference between the wet sample mass and the dry sample mass.

The GLOBE Program, University Corporation for Atmospheric Research (UCAR)

2003-08-01

125

Tropical Soil Chemistry  

DEFF Research Database (Denmark)

A new book that is particularly relevant as tropical countries experience increased pressure on land resources to improve agricultural production. To ensure sustainable land use, the potentials and limitations of different kinds of tropical soils must be known in relation to crop production and environmental protection. Tropical Soil Chemistry by Ole K. Borggaard provides an overview of the composition, occurrence, properties, processes, formation, and environmental vulnerability of various tropical soil types (using American Soil Taxonomy for classification). The processes and the external factors that affect soil processes are the same in tropical soils as in temperate region soils, but because of high temperature year round and occurrence in very stable landscapes, some (but not all) tropical soils possess special composition and properties. These features are highlighted in the book, and general soil chemical issues are also presented to assess when, why, and how tropical soils differ from soils in other regions. This knowledge can help agricultural specialists in the tropics establish sustainable crop production. Readers are assumed to be familiar with basic chemistry, physics, and mathematics at a level corresponding to introductory university courses. Knowledge of fundamental geology, geography, and soil science is also needed. The book can be purchased from the Department.

Borggaard, Ole K.

2008-01-01

126

Experimental unsaturated soil mechanics  

CERN Document Server

In this general report, experimental systems and procedures of investigating the hydro-mechanical behaviour of unsaturated soils are presented. The water retention properties of unsaturated soils are commented and linked to various physical parameters and properties of the soils. Techniques of controlling suction are described together with their adaptation in various laboratory testing devices. Some typical features of the mechanical behaviour of unsaturated soils are presented within an elasto-plastic framework. An attempt to describe the numerous and significant recent advances in the investigation of the behaviour of unsaturated soils, including the contributions to this Conference, is proposed.

Delage, Pierre

2008-01-01

127

Soil bioturbation. A commentary  

Science.gov (United States)

Organisms such as trees, ants, earthworms, termites are important components of the earth systems that have dominantly been thought of as abiotic. Despite an early focus on soil bioturbation by heavy-weights such as Charles Darwin and Nathanial Shaler in the late 19th century, sporadic attention to this theme has subsequently followed. Recent compilations demonstrate that soil bioturbation by fauna and flora is widespread across Earths terrestrial surface, and operates at geologically rapid rates that warrant further attention. Such biotic activity contributes to soil creep, soil carbon dynamics, and is critical in engineering the medium through which ecosystems draw their abiotic requirements. Soil and its biota are fundamental components of the Earth System. However, soil scientist focussed on the dominant paradigm of landscape evolution, and bioturbation was relegated. In fact, bioturbation is still not widely appreciated within the soil and earth system research community. Nevertheless, within the last decade a review of the impact of bioturbation was launched by authors such as Geoff S. Humphreys. Bioturbation is a complex process as new soil is formed, mounds are developed, soil is buried and a downslope transport of material is done. Bioturbation modify the soil texture and porosity, increase the nutrients and encourage the soil creep flux. A review of the State-of-the-Art of Bioturbation will be presented.

Cerdà, Artemi; Wilkinson, Marshall

2010-05-01

128

Soil heavy metals  

Energy Technology Data Exchange (ETDEWEB)

Human activities have dramatically changed the composition and organisation of soils. Industrial and urban wastes, agricultural application and also mining activities resulted in an increased concentration of heavy metals in soils. How plants and soil microorganisms cope with this situation and the sophisticated techniques developed for survival in contaminated soils is discussed in this volume. The topics presented include: the general role of heavy metals in biological soil systems; the relation of inorganic and organic pollutions; heavy metal, salt tolerance and combined effects with salinity; effects on abuscular mycorrhizal and on saprophytic soil fungi; heavy metal resistance by streptomycetes; trace element determination of environmental samples; the use of microbiological communities as indicators; phytostabilization of lead polluted sites by native plants; effects of soil earthworms on removal of heavy metals and the remediation of heavy metal contaminated tropical land. (orig.)

Sherameti, Irena [Jena Univ. (Germany). Inst. fuer Allgemeine Botanik und Pflanzenphysiologie; Varma, Ajit (eds.) [Amity Univ., Uttar Pradesh (India). Amity Inst. of Microbial Technology; Amity Science, Technology and Innovation Foundation, Noida, UP (India)

2010-07-01

129

How Can Soil Electrical Conductivity Measurements Control Soil Pollution?  

Directory of Open Access Journals (Sweden)

Full Text Available Soil pollution results from the build up of contaminants, toxic compounds, radioactive materials, salts, chemicals and cancer-causing agents. The most common soil pollutants are hydrocarbons, heavy metals (cadmium, lead, chromium, copper, zinc, mercury and arsenic, herbicides, pesticides, oils, tars, PCBs and dioxins. Soil Electrical Conductivity (EC is one of the soil physical properties w hich have a good relationship with the other soil characteristics. As measuring soil electrical conductivity is easier, less expensive and faster than other soil properties measurements, using a detector that can do on the go soil EC measurements is a good tool for obtaining useful information about soil pollution condition.

Mohammad Reza

2010-10-01

130

Soil aeration status of some austrian soils  

Directory of Open Access Journals (Sweden)

Full Text Available Observed climatic changes connected with an increase of temperature and a depression of ground water level motivated this joint investigation of Central Europe soils. The purpose of this paper is to characterize the aeration status of two sites representing typical regions for the agricultural production of Lower Austria (Wieselburg and Fuchsenbigl on the basis of results obtained in the frame of the multilateral Austrian-Czech-Hungarian-Polish-Slovak project on 'Assessment of Structure in Agricultural Soils' sponsored by the Austrian Ministry of Science and Research. The paper comprises results of measurements of different soil aeration properties such as: oxygen diffusion rate (ODR, redox potential (Eh, relative gas diffusion coefficient (DD0, air permeability (k and activity of soil dehydrogenase. Undisturbed soil cores were tested in the range of soil moisture tension from 0 hPa (pF 0 to 500 hPa (pF 2.7.Statistical analysis of relationships between tested parameters were performed.

Wimmer B.

1997-09-01

131

Phytoremediation of soil metals.  

Science.gov (United States)

The phytoremediation of metal-contaminated soils offers a low-cost method for soil remediation and some extracted metals may be recycled for value. Both the phytoextraction of metals and the phytovolatilization of Se or Hg by plants offer great promise for commercial development. Natural metal hyperaccumulator phenotype is much more important than high-yield ability when using plants to remove metals from contaminated soils. The hypertolerance of metals is the key plant characteristic required for hyperaccumulation; vacuolar compartmentalization appears to be the source of hypertolerance of natural hyperaccumulator plants. Alternatively, soil Pb and Cr6+ may be inactivated in the soil by plants and soil amendments (phytostabilization). Little molecular understanding of plant activities critical to phytoremediation has been achieved, but recent progress in characterizing Fe, Cd and Zn uptake by Arabidopsis and yeast mutants indicates strategies for developing transgenic improved phytoremediation cultivars for commercial use. PMID:9206007

Chaney, R L; Malik, M; Li, Y M; Brown, S L; Brewer, E P; Angle, J S; Baker, A J

1997-06-01

132

Soil function and "malfunction"  

Directory of Open Access Journals (Sweden)

Full Text Available Most of the scientists define soil from an “agronomic” point of view as the natural system delegated to sustain plantgrowth and agricultural productions on the whole. In this paper soil importance, even in “environmental and social”terms, is pointed out, considering soil as a natural body with its own functional characteristics, regardless ofits agronomic role and productive ability. Some studies show that soil acts as a thermal buffer and detoxifies thecirculating liquid phase. Actually soil is also the depository of the cultural heritage of the society who used it, bothas keeper of relics and manufactured products and as an expression of transformation processes and evolution trendcaused by man’s action itself.The need to protect and preserve soil has to be emphasized by stating its main importance not only as a maintenancesource for all the living beings but also as a factor of environmental control.

Elio Coppola

2008-04-01

133

Geomorphic Analysis of Soils  

Science.gov (United States)

Students are taken to a former plantation along a tidal river near Charleston, SC. The students are then shown how to sample and describe soils using an push-auger sampler, similar to those used in industry. After the demonstration, the students are taken to various locations on the plantation, including upland areas, wetlands, former agricultural areas, lowlands, and tidal marshes, to sample and make field descriptions of the various soils encountered. Students describe depths to horizons, soil color using Munsell Color Charts, soil texture, and any other pertinent properties. Students then prepare a formal technical write-up on the soils, their distribution, and how their sampling results compare to published soil data for the area. Designed for a geomorphology course Uses online and/or real-time data

Doyle, Briget

134

Soil-dithiocarbamate interactions  

International Nuclear Information System (INIS)

Soil is the ultimate repository of the pesticides applied for the control of plant pests and diseases. A variety of interactions like leaching, adsorption, chemical and microbial degradation etc take place between soil and pesticide. Results on work on two dialkyldithiocarbamates viz. thiram (tetramethylthiuram disulfide) and ziram (zinc dimethyldithiocarbamate) with respect to above interactions in soil are discussed and summarised. 35S-labelled thiram and ziram were used in the studies. (author)

135

Towards soil geostatistics  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In a brief survey of some issues in the application of geostatistics in soil science it is shown how the recasting of classical geostatistical methods in the linear mixed model (LMM) framework has allowed the more effective integration of soil knowledge (classifications, covariates) with statistical spatial prediction of soil properties. The LMM framework has also allowed the development of models in which the spatial covariance need not be assumed to be stationary. Such models are generall...

Lark, R. M.

2012-01-01

136

Earthworms and Soil Pollutants  

Directory of Open Access Journals (Sweden)

Full Text Available Although the toxicity of metal contaminated soils has been assessed with various bioassays, more information is needed about the biochemical responses, which may help to elucidate the mechanisms involved in metal toxicity. We previously reported that the earthworm, Eisenia fetida, accumulates cadmium in its seminal vesicles. The bio-accumulative ability of earthworms is well known, and thus the earthworm could be a useful living organism for the bio-monitoring of soil pollution. In this short review, we describe recent studies concerning the relationship between earthworms and soil pollutants, and discuss the possibility of using the earthworm as a bio-monitoring organism for soil pollution.

Kazuyoshi Tamae

2011-11-01

137

The Living Soil  

Science.gov (United States)

Soil is home to vast numbers of organisms, and even small sections of earth teem with a diverse array of life. This Topic in Depth takes a closer look at the world beneath our feet through the lens of soil biologists and ecologists. The first website (1) provides information about the activities of a Natural Environment Research Council-supported research program "on the biological diversity of soil biota and the functional roles played by soil organisms in key ecological processes." The second site (2) contains information about several research projects of the Ecology of Soil Organisms Theme Group at Wageningen University and Research Centre. The Theme Group studies "soil organisms at the population, community, and ecosystem level, to ultimately increase understanding of the role of soil organisms." The third site (3) contains a list of publications spanning the past fifteen years from members of the Soil Ecology Group at the University of Jyv'skyl". The site also provides basic information about group members, and concise descriptions of current research projects. From the USDA Natural Resources Conservation Service, the fourth website (4) contains an online version of the _Soil Biology Primer_, "an introduction to the living component of soil and how it contributes to agricultural productivity, and air and water quality. The Primer includes units describing the soil food web and its relationship to soil health, and units about bacteria, fungi, protozoa, nematodes, arthropods, and earthworms." The online version of the Primer contains the entire text of the original published version, but is missing some useful soil organism images. The fifth site (5) links to sixteen movies relating to different aspects of soil biology such as nematodes, mites, springtails, and protozoa. The movies were all produced by Dr. Thomas E. Loynachan, a Professor of Agronomy and Microbiology at Iowa State University. Finally, Soils Are Alive (6) was developed by Professor Lyn Abbot of the University of Western Australia and Jen Slater, a qualified secondary school science teacher. This website contains informative, concise sections addressing Soil Biology, Biological Processes, Living Components, and Ecosystem Management.

138

Soil physics and agriculture  

International Nuclear Information System (INIS)

The approach that integrates knowledge is very important in Agriculture, including farmers, extensionists, researchers and professors. The specialists, including the soil physicists, must have a global view of the crop production system. Therefore, their expertise can be useful for the society. The Essence of scientific knowledge is its practical application. The soil physics is a sub area of Agronomy. There are many examples of this specific subject related to Agriculture. This paper will focus, in general, the following cases: (i) erosion, environmental pollution and human health, (ii) plant population and distribution, soil fertility, evapo-transpiration and soil water flux density, and (iii) productivity, effective root depth, water deficit and yield

139

How Can Soil Electrical Conductivity Measurements Control Soil Pollution?  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Soil pollution results from the build up of contaminants, toxic compounds, radioactive materials, salts, chemicals and cancer-causing agents. The most common soil pollutants are hydrocarbons, heavy metals (cadmium, lead, chromium, copper, zinc, mercury and arsenic), herbicides, pesticides, oils, tars, PCBs and dioxins. Soil Electrical Conductivity (EC) is one of the soil physical properties w hich have a good relationship with the other soil characteristics. As measuring soil electrical condu...

Mohammad Reza; Sharifi, R. Alimardani And A.

2010-01-01

140

Soil sample for balloon flight  

Science.gov (United States)

Title : Soil sample for balloon flight Type : Antarctic EAM NSF Org: OD / OPP Date : July 29, 1992 ... soil in the vicinity of McMurdo Station (the preferred alternative); and ? collection of soil ...

 
 
 
 
141

Soil nematode communities in grasslands  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This thesis summarizes the results of five studies investigating the effect of plant species on soil nematode communities in grasslands. Nematodes (roundworms) are ubiquitous members of the soil fauna and have been much used as indicators of soil conditions. Plants have the ability to affect soil organisms through structural modification of the soil habitat and through the quantity and quality of organic matter that is returned to soil, in the form of plant litter and root exudates. The influ...

Viketoft, Maria

2007-01-01

142

UK Soil Research Audit  

Dec 10, 2003 ... The first stage of this work was to collect programme data from all known ... soil \\specific - policy questions have a soil component as part of a bigger, ... Research \\carried out for use by farmers/land managers lacked the input of ...

143

Prospective soils decontamination technology  

International Nuclear Information System (INIS)

Issues of land remediation and reduction of scopes of radioactive waste that require long-term storage are becoming ever more pressing. Radon Moscow has developed and tested a new technology for soil decontamination, combining physical and chemical treatment techniques. The article presents a new decontamination technology and parameters of removal Cs-137 from soil using various methods

144

Soil and vegetation surveillance  

Energy Technology Data Exchange (ETDEWEB)

Soil sampling and analysis evaluates long-term contamination trends and monitors environmental radionuclide inventories. This section of the 1994 Hanford Site Environmental Report summarizes the soil and vegetation surveillance programs which were conducted during 1994. Vegetation surveillance is conducted offsite to monitor atmospheric deposition of radioactive materials in areas not under cultivation and onsite at locations adjacent to potential sources of radioactivity.

Antonio, E.J.

1995-06-01

145

Small Soil Animals.  

Science.gov (United States)

Describes an inexpensive technique for providing student opportunities to observe and identify the variety of small animals living in the first few inches below the surface of the soil. A classification key to some small soil animals is also presented. (HM)

Seevers, Elmer R.

1978-01-01

146

Seasonal Soil Creep.  

Science.gov (United States)

The report for the first year is an investigation of seasonal creep of soil. Flexible pipes, which change position in response to creeping soil, have been installed in three areas on the San Francisco Peninsula and two areas near Cincinnati, Ohio. Measure...

R. W. Fleming

1976-01-01

147

Pavement and Soil Characteristics.  

Science.gov (United States)

The papers in the Record contain information on soil characteristics useful for pavement design. They are of interest to soil engineers and highway designers. These papers include a presentation of an estimate of the contribution of the subgrade to the to...

C. L. Monismith

1975-01-01

148

Creative Soil Conservation  

Science.gov (United States)

Take plant lessons outdoors with this engaging and inquiry-based activity in which third-grade students learn how to apply soil conservation methods to growing plants. They also collect data and draw conclusions about the effectiveness of their method of soil conservation. An added benefit to this activity is that the third-grade students played…

Smith, Martha

2010-01-01

149

Metastable Loess Soils  

Science.gov (United States)

The hydrocollapse of loess continues to cause major geotechnical problems throughout the world. Work is currently being conducted to develop a constitutive model to analyze the behavior of collapsing loess soils. This site discusses the development of this model and the methods used to validate it, which include the use of an artificial loess soil manufactured in the laboratory.

2008-07-31

150

Campus Field Soil Geomorphology  

Science.gov (United States)

In this activity, students have an opportunity to learn about the geomorphology and soils of your campus. Within a team, students collect soils information and use it to construct of stratigraphic cross-section and outline major geologic events in the history of a given site.

Dolliver, Holly

151

Soil Classification Using GATree  

CERN Document Server

This paper details the application of a genetic programming framework for classification of decision tree of Soil data to classify soil texture. The database contains measurements of soil profile data. We have applied GATree for generating classification decision tree. GATree is a decision tree builder that is based on Genetic Algorithms (GAs). The idea behind it is rather simple but powerful. Instead of using statistic metrics that are biased towards specific trees we use a more flexible, global metric of tree quality that try to optimize accuracy and size. GATree offers some unique features not to be found in any other tree inducers while at the same time it can produce better results for many difficult problems. Experimental results are presented which illustrate the performance of generating best decision tree for classifying soil texture for soil data set.

Bhargavi, P

2010-01-01

152

Soil Classification Using GATREE  

Directory of Open Access Journals (Sweden)

Full Text Available This paper details the application of a genetic programming framework forclassification of decision tree of Soil data to classify soil texture. The database containsmeasurements of soil profile data. We have applied GATree for generating classificationdecision tree. GATree is a decision tree builder that is based on Genetic Algorithms(GAs. The idea behind it is rather simple but powerful. Instead of using statistic metricsthat are biased towards specific trees we use a more flexible, global metric of tree qualitythat try to optimize accuracy and size. GATree offers some unique features not to befound in any other tree inducers while at the same time it can produce better results formany difficult problems. Experimental results are presented which illustrate theperformance of generating best decision tree for classifying soil texture for soil data set.

P.Bhargavi

2010-10-01

153

Soil invertebrates as bioindicators of urban soil quality  

International Nuclear Information System (INIS)

This study aimed at relating the abundance and diversity of invertebrate communities of urban soils to chemical and physical soil characteristics and to identify the taxa most sensitive or tolerant to soil stressors. The invertebrate community of five urban soils in Naples, Italy, was sampled. To assess soil quality invertebrate community indices (Shannon, Simpson, Menhinick and Pielou indices), Acarina/Collembola ratios, and the soil biological quality index (QBS) were calculated. The chemical and physical characteristics of the soils strongly differed. Abundance rather than taxa richness of invertebrates were more affected by soil characteristics. The community was more abundant and diverse in the soils with high organic matter and water content and low metal (Cu, Pb, Zn) concentrations. The taxa more resistant to the urban environment included Acarina, Enchytraeids, Collembola and Nematoda. Collembolans appeared particularly sensitive to changing soil properties. Among the investigated indices, QBS seems most appropriate for soil quality assessment. - Highlights: ? The abundance and diversity of invertebrate communities was related to properties and metal contents of urban soils. ? Several (biodiversity) indices were calculated and compared to evaluate soil quality. ? Metal contamination affected invertebrate density and diversity. ? The taxa more tolerant to metal contamination were Acarina, Enchytraeids, Collembola and Nematoda. ? The soil biological quality index QBS index was most appropriate for soil quality assessment. - Soil metal contamination negatively affected soil invertebrate abundance and diversity.

154

Soil bacteria for remediation of polluted soils  

Energy Technology Data Exchange (ETDEWEB)

Soil bacteria, specifically adapted to contaminated soils, may be used for the remediation of polluted soils. The Flemish research institute VITO has established a collection of bacteria, which were isolated from contaminated areas. This collection includes microbacteria degrading mineral oils (Pseudomonas sp., Acinetobacter sp. and others), microbacteria degrading polycyclic aromatic hydrocarbons (genera Sphingomonas and Mycobacterium), microbacteria degrading polychlorobiphenyls (genus Ralstonia and strains related to beta-Proteobacteria), and metal resistant bacteria with plasmid borne resistances to Cd, Zn, Ni, Co, Cu, Hg, and Cr. Bench-scale reactors were developed to investigate the industrial feasibility of bioremediation. Batch Stirred Tank Reactors were used to evaluate the efficiency of oil degraders. Soils, contaminated with non-ferrous metals, were treated using a Bacterial Metal Slurry Reactor. It was found that the reduction of the Cd concentration may vary strongly from sample to sample: reduction factors vary from 95 to 50%. Is was shown that Cd contained in metallic sinter and biologically unavailable Cd could not be removed.

Springael, D.; Bastiaens, L.; Carpels, M.; Mergaey, M.; Diels, L.

1996-09-18

155

Effect of compaction energy on soil suction of clayey soils  

International Nuclear Information System (INIS)

Soil suction is a fundamental physical property of unsaturated soils such as buffer materials, shallow foundation, dam foundation and pavement sub-grades, describing the potential with which a given soil at given water content adsorbs and retains pore water. From a thermodynamic standpoint, soil suction is the free energy of pore-water in a soil and is a function of relative humidity or moisture. This study was undertaken to evaluate the variations of soil suction with the moisture content for clayey soils. In particular, the effects of compaction energy on soil suction were investigated. The suction of unsaturated soil was determined for various conditions, covering a range of compacting efforts and water contents. Soils specimens were prepared by dynamic compaction and were compacted using 3 levels of compacting effort. The filter paper method was used to measure the total and matrix suctions of two clayey soils. Findings from these tests indicated that low plasticity soils have lower soil suction than high plasticity soils at a specific water content. Soil suction was observed to increase markedly with decreasing compaction energy on soils at low water contents. And at high water contents, soil suction is relatively insensitive to compaction energy. It was also found that compaction energy has more impact on the total suction than the matrix suction. For soils prepared using impact compaction, void ratio was found not a good index to predict soil suction, while the degree of saturation shows a good correlation with soil suction and is proposed to be used as a predictor for soil suction. (authors)

156

Soil gas radon response to environmental and soil physics variables  

International Nuclear Information System (INIS)

se to changes in soil permeability that result from variations in soil moisture levels. Further work is continuing on the model to enable it to properly account for the relative effects of advective transport of soil gas through cracks and diffusive mobility in the bulk soils

157

Introductory Soil Science Exercises Using USDA Web Soil Survey  

Science.gov (United States)

The USDA, Natural Resource Conservation Service (NRCS) Web Soil Survey is a valuable teaching tool for soil science education. By incorporating the Web Soil Survey into an undergraduate-level course, students are able to use the most detailed digital soil survey information without the steep learning curve associated with geographic information…

Post, Christopher J.; Mikhailova, Elena; McWhorter, Christopher M.

2007-01-01

158

Describing Soils: Calibration Tool for Teaching Soil Rupture Resistance  

Science.gov (United States)

Rupture resistance is a measure of the strength of a soil to withstand an applied stress or resist deformation. In soil survey, during routine soil descriptions, rupture resistance is described for each horizon or layer in the soil profile. The lower portion of the rupture resistance classes are assigned based on rupture between thumb and…

Seybold, C. A.; Harms, D. S.; Grossman, R. B.

2009-01-01

159

Ultrasound enhanced soil washing  

Energy Technology Data Exchange (ETDEWEB)

The development of an ultrasonic enhanced soil-washing process requires a comprehensive, well-designed experimental program, with the results carefully analyzed on the basis of known ultrasonic cleaning mechanisms. There has been no systematic work carried out to develop information on the important variables that can affect the efficacy of ultrasonic enhancement of contaminant removal from soil. The goal of this study is to examine the potential of ultrasonic energy to enhance soil washing and to optimize conditions. Ultrasonic energy potentially can be used in enhancing contaminant removal from the entire soil mix, or it can be used as a polishing operation on the fines portion of the soil mixture after traditional soil washing operations. The research study was designed to demonstrate that ultrasonic energy can: improve process performance, e.g., remove contaminants to lower residual concentrations; and improve process economics, e.g., shorter treatment (residence) times, less surfactant use. This process was demonstrated using soil contaminated with polycyclic aromatic hydrocarbons.

Meegoda, J.; Ho, W.; Bhattacharajee, M.; Wei, C.F.; Cohen, D.M.; Magee, R.S. [New Jersey Inst. of Technology, Newark, NJ (United States); Frederick, R.M. [Environmental Protection Agency, Edison, NJ (United States)

1995-12-31

160

Soil washing treatability study  

International Nuclear Information System (INIS)

Soil washing was identified as a viable treatment process option for remediating soil at the FEMP Environmental Management Project (FEMP). Little information relative to the specific application and potential effectiveness of the soil washing process exists that applies to the types of soil at the FEMP. To properly evaluate this process option in conjunction with the ongoing FEMP Remedial Investigation/Feasibility Study (RI/FS), a treatability testing program was necessary to provide a foundation for a detailed technical evaluation of the viability of the process. In August 1991, efforts were initiated to develop a work plan and experimental design for investigating the effectiveness of soil washing on FEMP soil. In August 1992, the final Treatability Study Work Plan for Operable Unit 5: Soil Washing (DOE 1992) was issued. This document shall be referenced throughout the remainder of this report as the Treatability Study Work Plan (TSWP). The purpose of this treatability study was to generate data to support initial screening and the detailed analysis of alternatives for the Operable Unit 5 FS

 
 
 
 
161

Iodine in soil  

International Nuclear Information System (INIS)

A literature study of the migration and the appearance of iodine isotopes in the bio-sphere particularly in soil is presented. Some important papers in the field of iodine appearance in soil and the appearance of 129I in the surroundings of reprocessing plants are discussed. The most important conclusions are: 1. Iodine binds to organic matter in the soil and also to some oxides of aluminium and iron. 2. If the iodine is not bound to the soil a large fraction of added 129I is volatilized after a rather short period. 3. The binding and also the volatilisation seems to be due to biological activity in the soil. It may take place within living microorganisms or by external enzymes excreted from microorganisms. 4. Due to variations in the composition of soil there may be a large variation in the distribution of 129I in the vertical profile of soil - usually most of the 129I in the upper layer - which also results in large variations in the 129I uptake to plants

162

SOIL Geo-Wiki: A tool for improving soil information  

Science.gov (United States)

Crowdsourcing is increasingly being used as a way of collecting data for scientific research, e.g. species identification, classification of galaxies and unravelling of protein structures. The WorldSoilProfiles.org database at ISRIC is a global collection of soil profiles, which have been 'crowdsourced' from experts. This system, however, requires contributors to have a priori knowledge about soils. Yet many soil parameters can be observed in the field without specific knowledge or equipment such as stone content, soil depth or color. By crowdsourcing this information over thousands of locations, the uncertainty in current soil datasets could be radically reduced, particularly in areas currently without information or where multiple interpretations are possible from different existing soil maps. Improved information on soils could benefit many research fields and applications. Better soil data could enhance assessments of soil ecosystem services (e.g. soil carbon storage) and facilitate improved process-based ecosystem modeling from local to global scales. Geo-Wiki is a crowdsourcing tool that was developed at IIASA for land cover validation using satellite imagery. Several branches are now available focused on specific aspects of land cover validation, e.g. validating cropland extent or urbanized areas. Geo-Wiki Pictures is a smart phone application for collecting land cover related information on the ground. The extension of Geo-Wiki to a mobile environment provides a tool for experts in land cover validation but is also a way of reaching the general public in the validation of land cover. Here we propose a Soil Geo-Wiki tool that builds on the existing functionality of the Geo-Wiki application, which will be largely designed for the collection and sharing of soil information. Two distinct applications are envisaged: an expert-oriented application mainly for scientific purposes, which will use soil science related language (e.g. WRB or any other global reference soil classification system) and allow experts to upload and share scientifically rigorous soil data; and an application oriented towards the general public, which will be more focused on describing well observed, individual soil properties using simplified classification keys. The latter application will avoid the use of soil science related terminology and focus on the most useful soil parameters such as soil surface features, stone content, soil texture, soil plasticity, calcium carbonate presence, soil color, soil pH, soil repellency, and soil depth. Collection of soil and landscape pictures will also be supported in Soil Geo-Wiki to allow for comprehensive data collection while simultaneously allowing for quality checking by experts.

Skalský, Rastislav; Balkovic, Juraj; Fritz, Steffen; See, Linda; van der Velde, Marijn; Obersteiner, Michael

2014-05-01

163

Parameterization of radiocaesium soil-plant transfer using soil characteristics  

International Nuclear Information System (INIS)

A model of radionuclide soil-plant transfer is proposed to parameterize the transfer factor by soil and soil solution characteristics. The model is tested with experimental data on the aggregated transfer factor Tag and soil parameters for 8 forest sites in Baden-Wuerttemberg. It is shown that the integral soil-plant transfer factor can be parameterized through radiocaesium exchangeability, capacity of selective sorption sites and ion composition of the soil solution or the water extract. A modified technique of (FES) measurement for soils with interlayer collapse is proposed. (author)

164

The Influence of Soil Particle on Soil Condensation Water  

Directory of Open Access Journals (Sweden)

Full Text Available 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 condensate water, reduce the evaporation and maintain relatively high moisture content in the top layer of soil.

Hou Xinwei

2013-06-01

165

Selenium in soil  

Directory of Open Access Journals (Sweden)

Full Text Available Selenium (Se is an essential microelement, necessary for normal functioning of human and animal organisms. Its deficiency in food and feed causes a number of diseases. In high concentrations, selenium is toxic for humans animals and plants. Soil provision with selenium affects its level in food and feed via nutrition chain. However, selenium reactivity and bioavailability depends not only on its total content in soil but also on its chemical forms. Distribution of the different forms of selenium depends on soil properties such as reaction, aeration, contents of clay and organic matter and microbiological activity.

?uvardi? Maja S.

2003-01-01

166

Development of soil taxation and soil classification as furthered by the Austrian Soil Science Society  

Science.gov (United States)

Soil taxation and soil classification are important drivers of soil science in Austria. However, the tasks are quite different: whereas soil taxation aims at the evaluation of the productivity potential of the soil, soil classification focusses on the natural development and - especially nowadays - on functionality of the soil. Since the foundation of the Austrian Soil Science Society (ASSS), representatives both directions of the description of the soil have been involved in the common actions of the society. In the first years it was a main target to improve and standardize field descriptions of the soil. Although both systems differ in the general layout, the experts should comply with identical approaches. According to this work, a lot of effort has been put into the standardization of the soil classification system, thus ensuring a common basis. The development, state of the art and further development of both classification and taxation systems initiated and carried out by the ASSS will be shown.

Baumgarten, Andreas

2013-04-01

167

Managing compost stability and amendment to soil to enhance soil heating during soil solarization.  

Science.gov (United States)

Soil solarization is a method of soil heating used to eradicate plant pathogens and weeds that involves passive solar heating of moist soil mulched (covered) with clear plastic tarp. Various types of organic matter may be incorporated into soil prior to solarization to increase biocidal activity of the treatment process. Microbial activity associated with the decomposition of soil organic matter may increase temperatures during solarization, potentially enhancing solarization efficacy. However, the level of organic matter decomposition (stability) necessary for increasing soil temperature is not well characterized, nor is it known if various amendments render the soil phytotoxic to crops following solarization. Laboratory studies and a field trial were performed to determine heat generation in soil amended with compost during solarization. Respiration was measured in amended soil samples prior to and following solarization as a function of soil depth. Additionally, phytotoxicity was estimated through measurement of germination and early growth of lettuce seedlings in greenhouse assays. Amendment of soil with 10%(g/g) compost containing 16.9 mg CO2/gdry weight organic carbon resulted in soil temperatures that were 2-4 °C higher than soil alone. Approximately 85% of total organic carbon within the amended soil was exhausted during 22 days of solarization. There was no significant difference in residual respiration with soil depth down to 17.4 cm. Although freshly amended soil proved highly inhibitory to lettuce seed germination and seedling growth, phytotoxicity was not detected in solarized amended soil after 22 days of field solarization. PMID:23422041

Simmons, Christopher W; Guo, Hongyun; Claypool, Joshua T; Marshall, Megan N; Perano, Kristen M; Stapleton, James J; Vandergheynst, Jean S

2013-05-01

168

Soil Microbes and soil microbial proteins: interactions with clay minerals  

International Nuclear Information System (INIS)

Bacterial enumeration in soil environments estimates that the population may reach approximately 1010 g-1 of soil and comprise up to 90% of the total soil microbial biomass. Bacteria are present in soils as single cells or multicell colonies and often strongly adsorb onto mineral surfaces such as sand and clay. The interactions of microbes and microbial biomolecules with these minerals have profound impacts on the physical, chemical and biological properties of soils. (Author)

169

Classification of El Rawakeeb Soil  

International Nuclear Information System (INIS)

Three soil profiles were dug at three different sites in El Rawakeeb Research Station. After description of their morphological features, nine soil samples were taken from the three soil profiles (three samples from each) to investigate their physical and chemical properties. Results showed that these soils could be classified as Fine, Loamy, Mixed, Hyperthermic, typic haplogysids. (Author)

170

Hydrologic characteristics of Nebraska soils  

Science.gov (United States)

The influence of the physical characteristics of soil on hydrology is frequently neglected. In this report, the effects of five characteristics on the hydrologic responses of soils in Nebraska are evaluated quantitatively, soils are grouped through use of a simplified coding system according to similarities in hydrologic responses, and are mapped according to these responses. General soils maps of the U.S. Department of Agriculture Soil Conservation Service and data for the physical properties of the soils proved well-suited to hydrologic interpretation. This interpretation of the maps and data led to the selection of three characteristics as classification variables: Average permeability of the 60-inch soil profile, average maximum soil slope, and depth to the seasonal high water table. Permeability of the least permeable horizon and available water capacity, although not needed as classification variables, are useful in explaining some of the hydrologic responses of soils. The primary soil units used in groupings and interpretation of the soils for this study are the soil associations. A computer program is presented that sorts the soils into groups and calculates statistics for each group. The 147 soil associations in Nebraska were thus sorted into 29 hydrologic soil groups. The location and extent of these hydrologic soil groups are shown on maps at scales of 1:750,000 and 1:250,000 for the State.

Dugan, Jack T.

1984-01-01

171

Soil and soil environmental quality monitoring in China: a review.  

Science.gov (United States)

Over the past few decades, numerous concerns have been raised in China over the issue of environmental sustainability. Various soil survey and monitoring programs have been carried out in China to study soil quality, and to provide a scientific basis for environment policy making. This paper provides an overview of past and current soil quality surveys and monitoring activities in China. This paper includes a summary of concerns over background concentrations of elements in soil, and soil environmental standards and guidelines in China. Levels of pollution in urban soil, agricultural soil, and soil in mining and smelting areas were compared using the concentrations and pollution indexes. In addition to soil surveys, soil monitoring is essential to study the data and to examine the effects of contaminants in soils. However, the current soil quality monitoring system was insufficient to accurately determine the soil quality status of soils across China. For accurate soil monitoring in China, it will be necessary to set up routine monitoring systems at various scales (national, provincial, and local scales), taking into consideration monitoring indicators and quality assurance. This is currently an important priority for the environmental protection administration of China. PMID:24875802

Teng, Yanguo; Wu, Jin; Lu, Sijin; Wang, Yeyao; Jiao, Xudong; Song, Liuting

2014-08-01

172

THE DIRT ON SOILS  

Science.gov (United States)

This keynote presentation will provide basic information regarding the physical, chemical, and biological importance of soils to 50 second grade teachers within the Cincinnati Public School System as part of a Hamilton County Department of Environmenatl Services Sois Workshop....

173

Soil Quality Indicators  

Feb 14, 2006 ... and conservation value. Further, to ... After consideration of the soil affect on food \\and fibre production, indicators for environmental interaction also ... stability and \\water content at a depth of 1 m . .... Tilled land* Untilled land**.

174

Soil degradation in Pakistan  

International Nuclear Information System (INIS)

This paper diagnoses the issues involved behind the current state, usage, interactions and linkages in the soils in Pakistan. The condition of soils is deteriorating due to developmental and environmental factors such as soil degradation, water pollution, fauna degeneration etc. Issues, problems and constraints faced in the management and usage of soils are diagnosed at different levels in the ecosystems predominant in Pakistan. The research questions propose effective solutions, types of instruments, methods or processes to resolve the issues within the various areas or ecosystems in the most sustainable and effective manner [23]. Biological solutions and methods can be applied at the sub-system level by private individuals or communities at a lower cost, and at a more localized level than engineering methods. Engineering methods may be suited for interventions at a system level rather than at a sub-system level; but even at this level they will be complementary with biological methods. (author)

175

Iodine dynamics in soils  

Science.gov (United States)

We investigated changes in iodine (129I) solubility and speciation in nine soils with contrasting properties (pH, Fe/Mn oxides, organic carbon and iodine contents), incubated for nine months at 10 and 20 °C. The rate of 129I sorption was greater in soils with large organic carbon contents (%SOC), low pH and at higher temperatures. Loss of iodide (I-) from solution was extremely rapid, apparently reaching completion over minutes-hours; iodate (IO3-) loss from solution was slower, typically occurring over hours-days. In all soils an apparently instantaneous sorption reaction was followed by a slower sorption process for IO3-. For iodide a faster overall reaction meant that discrimination between the two processes was less clear. Instantaneous sorption of IO3- was greater in soils with high Fe/Mn oxide content, low pH and low SOC content, whereas the rate of time-dependent sorption was greatest in soils with higher SOC contents. Phosphate extraction (0.15 M KH2PO4) of soils, ?100 h after 129I spike addition, indicated that concentrations of sorbed inorganic iodine (129I) were very low in all soils suggesting that inorganic iodine adsorption onto oxide phases has little impact on the rate of iodine assimilation into humus. Transformation of dissolved inorganic 129IO3- and 129I- to sorbed organic forms was modelled using a range of reaction- and diffusion-based approaches. Irreversible and reversible first order kinetic models, and a spherical diffusion model, adequately described the kinetics of both IO3- and I- loss from the soil solution but required inclusion of a distribution coefficient (kd) to allow for instantaneous adsorption. A spherical diffusion model was also collectively parameterised for all the soils studied by using pH, soil organic carbon concentration and combined Fe + Mn oxide content as determinants of the model parameters (kd and D/r2). The kinetic model parameters were not directly related to a single soil parameter; inclusion of pH, SOC, oxide content and temperature was necessary to describe the observed behaviour. From the temperature-dependence of the sorption data the activation energy (Ea) for 129IO3- transformation to organic forms was estimated to be ?43 kJ mol-1. The Ea value was independent of %SOC and was consistent with a reaction mechanism slower than pore diffusion or physical adsorption, but faster than most surface reactions.

Shetaya, W. H.; Young, S. D.; Watts, M. J.; Ander, E. L.; Bailey, E. H.

2012-01-01

176

Climate Strategic Soil Management  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The complex and strong link between soil degradation, climate change and food insecurity is a global challenge. Sustainable agricultural systems must be integral to any agenda to address climate change and variability, improve renewable fresh water supply and quality, restore degraded soils and ecosystems and advance food security. These challenges are being exacerbated by increasing population and decreasing per capita arable land area and renewable fresh water supply, the increasing freque...

Rattan Lal

2014-01-01

177

The Scoop on Soils  

Science.gov (United States)

This science-based storybook provides an introduction to soil description and sampling. Simon, Anita and Dennis follow their dog, Scoop, and find themselves in the middle of an adventure in soil. This is one of four storybooks under the title Elementary GLOBE; each book also has companion learning activities that complement the science covered in each story. GLOBE (Global Learning and Observation to Benefit the Environment) is a worldwide, hands-on, K-12 school-based science education program.

178

European Atlas of Soil Biodiversity  

DEFF Research Database (Denmark)

Soil is one of the fundamental components for supporting life on Earth. Most ecosystem processes and global functions that occur within soil are driven by living organisms that, in turn, sustain life above ground. However, despite the fact that soils are home to a quarter of all living species on Earth, life within the soil is often hidden away and suffers by being 'out of sight and out of mind'. What kind of life is there in soil? What do we mean by soil biodiversity? What is special about soil biology? How do our activities affect soil ecosystems? What are the links between soil biota and climate change? The first ever European Atlas of Soil Biodiversity uses informative texts, stunning photographs and maps to answer these questions and other issues. The European Atlas of Soil Biodiversity functions as a comprehensive guide allowing non-specialists to access information about this unseen world. The first part of the book provides an overview of the below ground environment, soil biota in general, the ecosystem functions that soil organism perform, the important value it has for human activities and relevance for global biogeochemical cycles. The second part is an 'Encyclopedia of Soil Biodiversity'. Starting with the smallest organisms such as the bacteria, this segment works through a range of taxonomic groups such as fungi, nematodes, insects and macro-fauna to illustrate the astonishing levels of heterogeneity of life in soil. The European Atlas of Soil Biodiversity is more than just a normal atlas. Produced by leading soil scientists from Europe and other parts of the world under the auspice of the International Year of Biodiversity 2010, this unique document presents an interpretation of an often neglected biome that surrounds and affects us all. The European Atlas of Soil Biodiversity is an essential reference to the many and varied aspects of soil. The overall goal of this work is to convey the fundamental necessity to safeguard soil biodiversity in order to guarantee life on this planet.

2010-01-01

179

Metals in urban playground soils  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Urban soils generally have elevated metal contents originating from both point and diffuse pollution sources. Urban areas designated for children, who are most susceptible to any negative health effects of soil metals, may therefore have elevated soil metal contents. Children ingest soil both directly and by putting dirty hands and objects in their mouths. The soil ingested involuntarily mainly comprise very fine particles that have a larger surface area for sorption and may therefore hold hi...

Ljung, Karin

2006-01-01

180

Soil strength and forest operations.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The use of heavy machinery and transport vehicles is an integral part of modern forest operations. This use often causes damage to the standing trees and to the soil. In this study the effects of vehicle traffic on the soil are analysed and the possible consequences for forest management discussed. The study is largely restricted to sandy and loamy soils because of their importance for Dutch forestry.Soil strength, defined as the resistance of soil structure against the impact of forces, can ...

Beekman, F.

1987-01-01

 
 
 
 
181

Soil function and "malfunction"  

Directory of Open Access Journals (Sweden)

Full Text Available Most of the scientists define soil from an “agronomic” point of view as the natural system delegated to sustain plant
growth and agricultural productions on the whole. In this paper soil importance, even in “environmental and social”
terms, is pointed out, considering soil as a natural body with its own functional characteristics, regardless of
its agronomic role and productive ability. Some studies show that soil acts as a thermal buffer and detoxifies the
circulating liquid phase. Actually soil is also the depository of the cultural heritage of the society who used it, both
as keeper of relics and manufactured products and as an expression of transformation processes and evolution trend
caused by man’s action itself.
The need to protect and preserve soil has to be emphasized by stating its main importance not only as a maintenance
source for all the living beings but also as a factor of environmental control.

Elio Coppola

2011-02-01

182

Soil physics and the water management of spatially variable soils  

International Nuclear Information System (INIS)

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)

183

Effects of environmental factors and soil properties on topographic variations of soil respiration  

Directory of Open Access Journals (Sweden)

Full Text Available Soil respiration rates were measured along different parts of a slope in (a an evergreen forest with mature soil and (b a deciduous forest with immature soil. The effects of soil temperature, soil moisture, and soil properties on soil respiration rates were estimated individually, and the magnitudes of these effects were compared between the deciduous and evergreen forests. In the evergreen forest with mature soil, soil properties had the greatest effect on soil respiration rates, followed by soil moisture and soil temperature. These results may be explained by different properties of soils that matured under different environments. Thus, we argue that the low soil respiration rates in Plot L of the evergreen forest resulted from soil properties and not from wet soil conditions. In the deciduous forest, soil respiration rates were more strongly affected by soil moisture and soil temperature than by soil properties, which were likely due to the immaturity of the forest soil.

K. Tamai

2009-11-01

184

Pesticide-soil microflora interactions in flooded rice soils  

International Nuclear Information System (INIS)

Isotope studies revealed that gamma and beta isomers of HCH (hexachlorocyclohexane) decomposed rapidly in nonsterile soils capable of attaining redox potentials of -40 to -100mV within 20 days after flooding. Degradation was slow, however, in soils low in organic matter and in soils with extremely low pH and positive potentials, even after several weeks of flooding. Under flooded conditions, endrin decomposed to six metabolites in most soils. There is evidence that biological hydrolysis of parathion is more widespread than hitherto believed, particularly under flooded soil conditions. Applications of benomyl (fungicide) to a simulated-oxidized zone of flooded soils favoured heterotrophic nitrification. (author)

185

Engineering Significant of Swelling Soils  

Directory of Open Access Journals (Sweden)

Full Text Available This study describes some of the most important swelling characters of expansive soils when used as foundation materials to support various types of civil engineering structures. Expansive soils are considered among difficult foundation materials and expand upon wetting and shrink upon losing moisture. They are considered problematic soils for architectural and civil engineers. These types of soils may cause minor to major structural damages to pavements as well as buildings. It is therefore essential to detect swelling soils from non-problematic foundation soils before any civil engineering projects are constructed over or adjacent to them. The study begins with definition of expansive soils and shows its distributions in the world as well as the basic causes for swelling potential that these type of soils poses. It is also shown that, the most probable depth of expansion to check for possible swelling potential for swelling soils is soil’s active zone. This zone is the most upper depth of expansive soil and it may extend up to 20 ft. (6 m below ground level. The moisture content of soil through active zone varies during different seasons while in lower part of expansive soil the moisture content stays constant during hot and cold season. Among various methods to check for swelling potential, plastic index and liquid limits are two most crucial factors, as these factors tend to increase, the swelling potential increase as well.

Behzad Kalantari

2012-08-01

186

Diagenetic variation in the Oregon Coast Range: Implications for rock strength, soil production, hillslope form, and landscape evolution  

Science.gov (United States)

mechanisms by which lithology modulates geomorphic processes are poorly known. In the Oregon Coast Range (OCR), rhythmically bedded sandstones of the Eocene Tyee Formation underlie steep, soil-mantled hillslopes, with relatively uniform ridge-valley spacing. These characteristic landforms are perturbed where diagenetic variations manifest as resistant cliffs. Here we use petrology, rock mechanics, and lidar to characterize grain-scale variations in rock properties and their influence on rock strength, hillslope processes, and landscape morphology in two adjacent watersheds. Petrographic analyses suggest that a suite of diagenetic products in the "resistant" bedrock account for a 2.5 times increase in tensile strength relative to "typical" Tyee bedrock. Our reference catchment exhibits negligible resistant outcrops, and consistent hillslope gradients and longitudinal valley profiles. By contrast, the adjacent catchment teems with resistant, 1 to 10 m thick, noncontiguous sandstone beds that form hanging valleys with gentle upstream hillslopes and anomalously narrow valleys. Mechanical and topographic analyses suggest that the low fracture density characteristic of these resistant beds may render them relatively impervious to comminution by tree root activity, the dominant OCR soil production mechanism. Based on both hillslope gradient- and hilltop curvature-erosion models, we estimate that hillslopes perched above resistant beds erode at approximately half the pace of hillslopes unencumbered by downstream knickpoints. The diagenetic variations likely influence relief at the watershed scale. Depositional position and diagenetic processes appear to control the occurrence of resistant beds, providing a framework to quantify how seemingly subtle variations in rock properties can impose first-order controls on landscape form and evolution.

Marshall, Jill A.; Roering, Joshua J.

2014-06-01

187

Shrinking Behaviour of Badland Soil Under Different Soil Covers  

Directory of Open Access Journals (Sweden)

Full Text Available Indicators used to estimate the soil structure stability facing erosion are the basis of major indicators of soil quality, and their behaviour is affected by permanent soil properties, vegetation and management. The relation between the pore-volume fraction occupied by water and the pore size distribution in clay soils is studied by the shrinkage curve describing clay soil porosity dynamics as a function of soil moisture. The aim of this work is to study the shrinking behaviour of the surface soil in a badland site through the shrinkage curve and to assess its relations with vegetation. Six treatments with different soil vegetation cover and aspect were selected on a badland site in Pisticci (Southern Italy. Shrinkage curves were built from natural aggregates collected in the 0-10 cm soil depth. Soil stability under shaking in water was also determined, with pre-treatments in water, alcohol and benzene for the determination of the SSI (Soil Stability Index. Soil organic matter, electrical conductivity, ESP were determined in order to investigate the relations between soil cover, chemical properties, SSI and shrink-swell behaviour. Vegetation was associated with lower soil salinity and ESP, and higher soil organic matter content. Vegetated sites showed a higher SSI and a lower overall swelling. The shrinkage curves for samples from vegetated areas lack of the structural phase of shrinkage, likely due to the combined effect of lower ESP and the mechanical effect of plant roots. All soil properties and indicators point to a higher stability of soils under grass in the south aspect and under shrub in the north one.

Teodoro Di Tommaso

188

Shrinking Behaviour of Badland Soil Under Different Soil Covers  

Directory of Open Access Journals (Sweden)

Full Text Available Indicators used to estimate the soil structure stability facing erosion are the basis of major indicators of soil quality, and their behaviour is affected by permanent soil properties, vegetation and management. The relation between the pore-volume fraction occupied by water and the pore size distribution in clay soils is studied by the shrinkage curve describing clay soil porosity dynamics as a function of soil moisture. The aim of this work is to study the shrinking behaviour of the surface soil in a badland site through the shrinkage curve and to assess its relations with vegetation. Six treatments with different soil vegetation cover and aspect were selected on a badland site in Pisticci (Southern Italy. Shrinkage curves were built from natural aggregates collected in the 0-10 cm soil depth. Soil stability under shaking in water was also determined, with pre-treatments in water, alcohol and benzene for the determination of the SSI (Soil Stability Index. Soil organic matter, electrical conductivity, ESP were determined in order to investigate the relations between soil cover, chemical properties, SSI and shrink-swell behaviour. Vegetation was associated with lower soil salinity and ESP, and higher soil organic matter content. Vegetated sites showed a higher SSI and a lower overall swelling. The shrinkage curves for samples from vegetated areas lack of the structural phase of shrinkage, likely due to the combined effect of lower ESP and the mechanical effect of plant roots. All soil properties and indicators point to a higher stability of soils under grass in the south aspect and under shrub in the north one.

Michele Perniola

2011-02-01

189

Effects of Land Cover / Land Use, Soil Texture, and Vegetation on the Water Balance of Lake Chad Basin  

Science.gov (United States)

Lake Chad Basin (LCB) has experienced drastic changes of land cover and poor water management practices during the last 50 years. The successive droughts in the 1970s and 1980s resulted in the shortage of surface water and groundwater resources. This problem of drought has a devastating implication on the natural resources of the Basin with great consequence on food security, poverty reduction and quality of life of the inhabitants in the LCB. Therefore, understanding the effects of land use / land cover must be a first step to find how they disturb cycle especially the groundwater in the LCB. The abundance of groundwater is affected by the climate change through the interaction with surface water, such as lakes and rivers, and disuse recharge through an infiltration process. Quantifying the impact of climate change on the groundwater resource requires reliable forecasting of changes in the major climatic variables and other spatial variations including the land use/land cover, soil texture, topographic slope, and vegetation. In this study, we employed a spatially distributed water balance model WetSpass to simulate a long-term average change of groundwater recharge in the LCB of Africa. WetSpass is a water balance-based model to estimate seasonal and spatial distribution of surface runoff, interception, evapotranspiration, and groundwater recharge. The model is especially suitable for studying the effect of land use/land cover change on the water regime in the LCB. The present study describes the concept of the model and its application to the development of recharge map of the LCB. The study shows that major role in the water balance of LCB. The mean yearly actual evapotranspiration (ET) from the basin range from 60mm - 400 mm, which is 90 % (69mm - 430) of the annual precipitation from 2003 - 2010. It is striking that about 50 - 60 % of the total runoff is produced on build-up (impervious surfaces), while much smaller contributions are obtained from vegetated, bare soil and open water surfaces. The result of this study also shows that runoff is high in the clay, clay loam and sandy-clay loam due to the lack of infiltration process in clay soil from capping or crusting or sealing of the soil pores, therefore this situation will aid runoff. The application of the WetSpass model shows that precipitation, soil texture and land use / land cover are three controlling factors affecting the water balance in the LCB. Key words: Groundwater recharge, surface runoff, evapotranspiration, water balance, meteorological, draught, Landuse changes, climate changes, WetSpass, GIS.

Babamaaji, R. A.; Lee, J.

2013-12-01

190

Use of Landsat imagery to detect land cover changes for monitoring soil sealing; case study: Bologna province (Italy)  

Science.gov (United States)

Landsat archives (made accessible by USGS at no charge since 2011) have made available to the scientific community a large amount of satellite multispectral images, providing new opportunities for environmental information, such as the analysis of land use/cover changes, which represent important tools for planning and sustainable land management. Processing a time series images, the creation of land cover maps has been improved in order to analyze phenomena such as the soil sealing. The main topic of this work is in fact the detection of roads and buildings construction or everything that involve soil removing. This subject is highly relevant, given the impact of the phenomenon on land use planning, environmental sustainability, agricultural policies and urban runoff. The analysis, still in progress, has been applied to Bologna Province (Emilia-Romagna Region, Italy) that covers 3703 Km2. This area is strongly urbanized: 8,9% of the total surface is sealed against a national value of 6,7%, with the soil sealing rate which has been defined from recent studies as the fourth Italian value in the 2001/2011 period. Other information available for this territory derive from CORINE Land Cover and Copernicus Projects. In the first one, the minimum mapping unit is 25 ha and the one for change is 5 ha; these values are too large for an accurate detection of the soil sealing dynamics. On the other hand, the Copernicus Project provides an imperviousness layer with a better resolution (20x20 m2), but its maps start from 2006. Therefore, the potential of multispectral remote sensing analysis over large areas and the multitemporal Landsat availability have been combined for a better knowledge about land cover changes. For this work, Landsat 5 and Landsat 8 images have been acquired between 1987 and 2013, according to basic requirements as low cloud cover and a common acquisition season (summer). A supervised pixel-based classification has been performed, with maximum likelihood algorithm. Due to landscape heterogeneity, classification has been improved with auxiliary data, such as NDVI. Therefore, the obtained maps have been compared with a post-classification change detection procedure in order to quantify land use changes, with particular attention to the soil sealing increase.

Casciere, Rossella; Franci, Francesca; Bitelli, Gabriele

2014-08-01

191

Soil mechanics and analysis of soils overlying cavitose bedrock  

International Nuclear Information System (INIS)

The stability of the residual soils existing at the West Chestnut Ridge Site, Oak Ridge Reservation, Tennessee, was evaluated. The weathered bedrock below this residual soil contains numerous solution cavities, and several karst features were identified. The West Chestnut Ridge site was evaluated with respect to deformation and collapse of the residual soil into the bedrock cavities. A finite element analysis investigated the effects of bedrock cavity radius, thickness of soil overburden, and surface surcharge upon the deformational and stability characteristics of the residual soil. The results indicate that for small cavity radii, the thickness of the soil cover has little effect on the zone of yielded soil. For large cavity radii, a smaller zone of distressed soil occurs under thick soil cover than under thin soil cover. Dimensionless curves are presented to enable the prediction of the vertical extent of the zone of yielded soil for a range of site geometries. Although the thick soil deposits (100 feet or greater) typically found on the ridges result in high stresses adjacent to the cavity, the area of the distressed or yielded soil is small and unlikely to extend to the surface. In addition, the surface deformation or subsidence is expected to be minimal. Thus, the siting of waste facilities on the ridges where the overburden is maximum would tend to reduce the effects of deformation into the cavities. 29 refs., 37 figs., 7 tabs

192

Soils and the soil cover of the Valley of Geysers  

Science.gov (United States)

The results of field studies of the soil cover within the tourist part of the Valley of Geysers in Kamchatka performed in 2010 and 2011 are discussed. The morphology of soils, their genesis, and their dependence on the degree of hydrothermal impact are characterized; the soil cover patterns developing in the valley are analyzed. On the basis of the materials provided by the Kronotskii Biospheric Reserve and original field data, the soil map of the valley has been developed. The maps of vegetation conditions, soil temperature at the depth of 15 cm, and slopes of the surface have been used for this purpose together with satellite imagery and field descriptions of reference soil profiles. The legend to the soil map includes nine soil units and seven units of parent materials and their textures. Soil names are given according to the classification developed by I.L. Goldfarb (2005) for the soils of hydrothermal fields. The designation of soil horizons follows the new Classification and Diagnostic System of Russian Soils (2004). It is suggested that a new horizon—a thermometamorphic horizon TRM—can be introduced into this system by analogy with other metamorphic (transformed in situ) horizons distinguished in this system. This horizon is typical of the soils partly or completely transformed by hydrothermal impacts.

Kostyuk, D. N.; Gennadiev, A. N.

2014-06-01

193

Remediation of contaminated soils  

Energy Technology Data Exchange (ETDEWEB)

At least three types of zones of contamination exist whenever there is a chemical release. The impact of Non-Aqueous-Phase Liquids (NAPL) on soils and groundwater, together with the ultimate transport and migration of constituent chemicals in their dissolved or sorbed states, had led environmentalists to develop several techniques for cleaning a contaminated soil. Zone 1 represents the unsaturated zone which could be contaminated to retention capacity by both Dense Non-Aqueous-Phase Liquids (DNAPL) and Light Non-Aqueous-Phase Liquids (LNAPL). Zone 2 represents residual DNAPL or LNAPL contamination found below the groundwater table in the saturated zone. Zone 3 is represented by either the presence of NAPL dissolved in the aqueous phase, volatilized in the unsaturated zone or sorbed to either saturated or unsaturated soils. Cleanup of petroleum contaminated soils is presented in this paper. Among several techniques developed for this purpose, in-situ biological remediation is discussed in detail as a technique that does not involve excavation, thus, the costs and disruption of excavating soil are eliminated.

Radhakrishnan, R.; Ariza, C.H. [Prairie View A and M Univ., TX (United States). Dept. of Civil Engineering

1997-07-01

194

Remediation of contaminated soils  

International Nuclear Information System (INIS)

At least three types of zones of contamination exist whenever there is a chemical release. The impact of Non-Aqueous-Phase Liquids (NAPL) on soils and groundwater, together with the ultimate transport and migration of constituent chemicals in their dissolved or sorbed states, had led environmentalists to develop several techniques for cleaning a contaminated soil. Zone 1 represents the unsaturated zone which could be contaminated to retention capacity by both Dense Non-Aqueous-Phase Liquids (DNAPL) and Light Non-Aqueous-Phase Liquids (LNAPL). Zone 2 represents residual DNAPL or LNAPL contamination found below the groundwater table in the saturated zone. Zone 3 is represented by either the presence of NAPL dissolved in the aqueous phase, volatilized in the unsaturated zone or sorbed to either saturated or unsaturated soils. Cleanup of petroleum contaminated soils is presented in this paper. Among several techniques developed for this purpose, in-situ biological remediation is discussed in detail as a technique that does not involve excavation, thus, the costs and disruption of excavating soil are eliminated

195

Soil pollution and land contamination  

Energy Technology Data Exchange (ETDEWEB)

Chapter 14 of the book identifies soil pollutants and their sources - these include: heavy metals (from mining, smelting, forestry, waste disposal, fossil fuel combustion etc.); hydrocarbon pollutants (from fuel storage and distribution, solvent leakage etc.); toxic organic micropollutants (e.g. pesticides); sewage sludge and manures; and radionuclides. It discusses transport mechanisms conveying pollutants to soils, the properties of soils affecting the behaviour of pollutants, the degradation of organic pollutants in soils, and the consequences of soil pollution. Analytical procedures for soil pollutants are described. Selected case studies of contamination associated with gasworks, industrial sites, smelters and metal mining are reported. 35 refs., 4 tabs.

Alloway, B.J. [University of Reading, Reading (United Kingdom). Dept. of Soil Science

1996-12-31

196

Soil Genesis and Development, Lesson 5 - Soil Classification and Geography  

Science.gov (United States)

This lesson discusses the characteristics of the 12 soil orders defined by the USDA soil classification system, the major factors involved with their formation, and their geographic distribution across the USA and the world.

197

Bioremediation of contaminated soil  

International Nuclear Information System (INIS)

Microorganisms, especially bacteria, yeast and fungi are capable of degrading many kinds of xenobiotic compounds and toxic chemicals such as petroleum hydrocarbon compounds. These microorganisms are ubiquitous in nature and, despite their enormous versatility, there are numerous cases in which long-term contamination of soil and groundwater has been observed. The persistence of the contamination is usually caused by the inability of microorganisms to metabolize these compounds under the prevailing environmental condition. This paper reports on biological remediation of contaminated sites which can be accomplished by using naturally-occurring microorganisms to treat the contaminants. The development of a bioremediation program for a specific contaminated soil system usually includes: A thorough site/soil/waste characterization; Treatability studies

198

Soil Litter: Unidentified Species  

Science.gov (United States)

In this two-minute sound segment, with the calls of a wood thrush in the background, a soil biologist discusses the probability that new species can be discovered in any handful of soil. He claims that when you pick up a handful of soil anywhere, whether it is in your backyard or in a forest, if you look at it closely enough, there will be organisms there that we have never seen before, especially microbial organisms. This site is an archive of a daily radio program called Pulse of the Planet, which provides its listeners with a portrait of Planet Earth, tracking the rhythms of nature, culture and science worldwide and blending interviews and extraordinary natural sound. The site also provides a written transcript of the broadcast.

2006-06-28

199

Saline waters and soil quality  

Directory of Open Access Journals (Sweden)

Full Text Available The processes of secondary salinization due to anthropic actions are considered one of the most important environmental emergencies owing to their level of dangerousness. The soils of the dry areas of the Mediterranean basin are particularly prone to these processes. In such environments, it is imperative to resort to irrigation that allow for the reduction of risks due to soil moisture deficit and for the stabilization of yields. Frequently, saline waters are used that cause a lowering of the soil quality. If on one hand the presence of salts can benefit the soils mainly improving soil structure, on the other high levels of salts produce negative effects on soils and crops.When sodium prevails problems of soil quality can rise such as structure degradation, low hydraulic conductivity, soil sealing. The processes of secondary soil salinization due to the use of saline waters for irrigation are particularly evident in our Country among others. In Italy, saline soils are mainly distributed in long strips of the coastal belt of the Tyrrhenian sea and Adriatic sea, in the coastal belt of Apulia, Basilicata and Sardinia and in wide areas of Sicily. It is not possible to suggest general actions to combat soil salinization because we must take into consideration that in the relationship soil-water two different quality concept interact: one linked to the soils, the other to the waters.

Carmelo Dazzi

200

Saline waters and soil quality  

Directory of Open Access Journals (Sweden)

Full Text Available The processes of secondary salinization due to anthropic actions are considered one of the most important environmental emergencies owing to their level of dangerousness. The soils of the dry areas of the Mediterranean basin are particularly prone to these processes. In such environments, it is imperative to resort to irrigation that allow for the reduction of risks due to soil moisture deficit and for the stabilization of yields. Frequently, saline waters are used that cause a lowering of the soil quality. If on one hand the presence of salts can benefit the soils mainly improving soil structure, on the other high levels of salts produce negative effects on soils and crops.When sodium prevails problems of soil quality can rise such as structure degradation, low hydraulic conductivity, soil sealing. The processes of secondary soil salinization due to the use of saline waters for irrigation are particularly evident in our Country among others. In Italy, saline soils are mainly distributed in long strips of the coastal belt of the Tyrrhenian sea and Adriatic sea, in the coastal belt of Apulia, Basilicata and Sardinia and in wide areas of Sicily. It is not possible to suggest general actions to combat soil salinization because we must take into consideration that in the relationship soil-water two different quality concept interact: one linked to the soils, the other to the waters.

Carmelo Dazzi

2011-02-01

 
 
 
 
201

SOIL AND LEACHED BLACK SOIL ENVIRONMENTAL EVALUATION OF WEST CAUCASUS ????????-????????????? ?????? ????????? ????????????? ????????? ????????????  

Directory of Open Access Journals (Sweden)

Full Text Available The analysis of foreign and domestic methods to evaluate soil productivity sowings has been presented. It has shown the need for soil environmental assessment in the West Central Caucasus. The soil-environmental index and index scores for an experimental field of individual crops rotation, which will promptly assess the fertility of the soil, give recommendations for rational allocation of fertilizer has been given

Slyusarev V. N.

2013-05-01

202

COLLABORATIVE RESEARCH: STREAMFLOW, URBAN RIPARIAN ZONES, BMPS, AND IMPERVIOUS SURFACES  

Science.gov (United States)

The U.S. EPA Landscape Ecology Branch (LEB) in Research Triangle Park, North Carolina is currently conducting collaborative landscape/stream ecology research in the Clarksburg Special Protection Area (CSPA) in Montgomery County, Maryland. The CSPA subwatersheds are on the outer e...

203

Effects of environmental factors and soil properties on topographic variations of soil respiration  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Soil respiration rates were measured along different parts of a slope in (a) an evergreen forest with mature soil and (b) a deciduous forest with immature soil. The effects of soil temperature, soil moisture, and soil properties on soil respiration rates were estimated individually, and the magnitudes of these effects were compared between the deciduous and evergreen forests. In the evergreen forest with mature soil, soil properties had the greatest effect on soil respiration rates, followed ...

Tamai, K.

2009-01-01

204

Soil monitoring instrumentation  

International Nuclear Information System (INIS)

The Los Alamos Scientific Laboratory (LASL) has an extensive program for the development of nondestructive assay instrumentation for the quantitative analysis of transuranic (TRU) materials found in bulk solid wastes generated by Department of Energy facilities and by the commercial nuclear power industry. Included are wastes generated in decontamination and decommissioning of outdated nuclear facilities as well as wastes from old waste burial ground exhumation programs. The assay instrumentation is designed to have detection limits below 10 nCi/g wherever practicable. Because of the topic of this workshop, only the assay instrumentation applied specifically to soil monitoring will be discussed here. Four types of soil monitors are described

205

Iodine dynamics in soils  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We investigated changes in iodine (129I) solubility and speciation in nine soils with contrasting properties (pH, Fe/Mn oxides, organic carbon and iodine contents), incubated for nine months at 10 and 20 °C. The rate of 129I sorption was greater in soils with large organic carbon contents (%SOC), low pH and at higher temperatures. Loss of iodide (I?) from solution was extremely rapid, apparently reaching completion over minutes–hours; iodate () loss from solution was slower, typically oc...

Shetaya, W. H.; Young, S. D.; Watts, M. J.; Ander, E. L.; Bailey, E. H.

2012-01-01

206

Soil Biogeochemical Cycles  

Science.gov (United States)

This group activity charges students with teaching their colleagues about the biogeochemical cycle of one key soil element (e.g., either C, N, S, P, Ca, or Fe). Students are given a single class period to summarize their knowledge and to develop a lesson that includes (1) an organized, 5-8 minute oral presentation, (2) a graphical, conceptual model of their assigned element's soil-biogeochemical cycle, and (3) a list of discussion questions with which to engage their colleagues on the other teams. A second class session is used to refine and to expand upon the submitted models as necessary.

Robins, Colin

207

Soil Fertility Protocol  

Science.gov (United States)

The purpose of this resource is to measure the amounts of nitrogen, phosphorous and potassium in each horizon in a soil profile. Using a NPK test kit, students mix a dry, sieved soil sample into a solution and chemically extract the N, P, and K as nitrate, phosphate, and potassium. The N, P, and K amounts in the sample are determined by comparing the solution to a color chart. Students describe the N, P, K amounts as high, medium, low, or none. These measurements are conducted three times for each horizon.

The GLOBE Program, University Corporation for Atmospheric Research (UCAR)

2003-08-01

208

A Laboratory Exercise Relating Soil Energy Budgets to Soil Temperature  

Science.gov (United States)

Enrollment by students in degree programs other than traditional horticulture, agronomy, and soil science has increased in basic plant and soil science courses. In order to broaden the appeal of these courses to students from majors other than agriculture, we developed a hands-on laboratory exercise relating the basic concepts of a soil energy…

Koenig, Richard T.; Cerny-Koenig, Teresa; Kotuby-Amacher, Janice; Grossl, Paul R.

2008-01-01

209

An alternative to soil taxonomy for describing key soil characteristics  

Science.gov (United States)

We are pleased to see the letter by Schimel and Chadwick (Front Ecol Environ 2013; 11[8]: 405–06), highlighting the importance of soil characterization in ecological and biogeochemical research and explaining the value of soil taxonomy, and we agree with the authors that reporting soil

Duniway, Michael C.; Miller, Mark E.; Brown, Joel R.; Toevs, Gordon

2013-01-01

210

Occurrence of entomopathogenic fungi in arable soil and meadow soil  

Directory of Open Access Journals (Sweden)

Full Text Available The samples of soil for experiment were taken from arable field and meadow. Larvae of Laspeyresia pomonella and Plodia interpuactella were used as an "insect bait" for isolation of entomopathogenic fungi from the soil. Beauveria bassiana, Metarhizium anisopliae, Paecilomyces farinosus and P. fumosoroseus were isolated from both kinds of soil.

Ryszard Mi?tkowski

1992-12-01

211

About zonality of introzonality soils  

Directory of Open Access Journals (Sweden)

Full Text Available This article presents arguments to demonstrate that not only background soils (podzol, black earth, but also introzonal ones, which are irregularly deposited among the predominant soils, are subject to latitudinal zonality.

Parakshin Yu.

2013-01-01

212

CONSIDERATIONS ON SOIL CARBON MANAGEMENT  

Directory of Open Access Journals (Sweden)

Full Text Available Soil organic carbon is important for the functioning of ecosystems andagro-ecosystems, having a major influence on the physical structure of the soil and its ability to store water. Loss of soil organic carbon can therefore lead to a reduction in soil fertility and land degradation. The content of organic carbon in a soil is determined by losses of organic carbon (through decomposition, erosion of particlesand losses through dissolved organic matter and inputs of organic carbon.Thus, worldwide, soil management to increase the content of soil organic carbon involves measures that reduce losses and/or measures that increase inputs. Carbon management is important for many problems that involve soils.

Adriana Nicoleta Ungura?u

2012-10-01

213

Soil texture; 1 : 500 000  

International Nuclear Information System (INIS)

The characteristics of soil texture are based on an abundant database of the agricultural and forest soils. The character of the texture of the upper soil horizons is assessed. The colour scale represents the classes of texture, and the raster distinguishes the individual classes of stoniness (in mountain ranges) or graveliness in the river alluvia. Soils with at least 10 % of area representation of rock basement are classified as very rocky. Very rocky soils are mostly rankers to Lithosols in the mountain areas of Slovakia. Medium stony are Cambisols to rankers on the crystalline rocks and volcanic complexes. The relatively heaviest soils are to be found in the Vychodoslovenska nizina Lowland, the lightest soils occur in the Zahorska nizina Lowland with prevalence of soils on aeolian sands. (authors)

214

Estimating Soil Water Retention and Unsaturated Soil Hydraulic Conductivity of Aggregated Soils Using the Additivity Model  

Science.gov (United States)

Soil-water potential and hydraulic conductivity relationships with soil water content are needed for many plant and soil-water studies. Conventional soil pore space model lying in the base of "one pore region - one continuum", described by pair of water retention and unsaturated soil hydraulic functions, often oversimplifies representation of variably saturated porous media as a homogeneous textural pore space. Soil structure has a major effect on soils ability to retain and to conduct water. This is especially right for aggregated soils in which pore space consists of interconnected intra- and inter-aggregate pores with distinct hydraulic properties. When a proportion of the inter-aggregate pore space is significant, in many cases the conventional description of water flow provides results that don't much an experimental data. In case of developed "aggregated soil" based on the concept "two pore regions - two continuums" soil pore space is described by two pair of both unsaturated soil hydraulic functions. A special model to estimate these functions is developed based on input data of bulk and aggregate density, structural and textural component distributions. This model was tested with experimental data measured of water retention and hydraulic conductivity of soil cores consisting of aggregates with sizes within narrow ranges. Cores were fabricated from separated individual aggregate fractions of Halpic Chernozem, Podzoluvisol, Halpic Kastanozem soils and artificially prepared aggregates. The obtained results demonstrate the sensitivity of the "additivity" model to estimate both unsaturated soil hydraulic functions for each pore regions. Keywords: aggregated soil, soil structure, soil water retention, additivity model

Zeiliger, A.; Ermolaeva, O.

2009-04-01

215

Relationships between soil physicochemical, microbiological properties, and nutrient release in buffer soils compared to field soils.  

Science.gov (United States)

The retention of nutrients in narrow, vegetated riparian buffer strips (VBS) is uncertain and underlying processes are poorly understood. Evidence suggests that buffer soils are poor at retaining dissolved nutrients, especially phosphorus (P), necessitating management actions if P retention is not to be compromised. We sampled 19 buffer strips and adjacent arable field soils. Differences in nutrient retention between buffer and field soils were determined using a combined assay for release of dissolved P, N, and C forms and particulate P. We then explored these differences in relation to changes in soil bulk density (BD), moisture, organic matter by loss on ignition (OM), and altered microbial diversity using molecular fingerprinting (terminal restriction fragment length polymorphism [TRFLP]). Buffer soils had significantly greater soil OM (89% of sites), moisture content (95%), and water-soluble nutrient concentrations for dissolved organic C (80%), dissolved organic N (80%), dissolved organic P (55%), and soluble reactive P (70%). Buffer soils had consistently smaller bulk densities than field soils. Soil fine particle release was generally greater for field than buffer soils. Significantly smaller soil bulk density in buffer soils than in adjacent fields indicated increased porosity and infiltration in buffers. Bacterial, archaeal, and fungal communities showed altered diversity between the buffer and field soils, with significant relationships with soil BD, moisture, OM, and increased solubility of buffer nutrients. Current soil conditions in VBS appear to be leading to potentially enhanced nutrient leaching via increasing solubility of C, N, and P. Manipulating soil microbial conditions (by management of soil moisture, vegetation type, and cover) may provide options for increasing the buffer storage for key nutrients such as P without increasing leaching to adjacent streams. PMID:22370402

Stutter, Marc I; Richards, Samia

2012-01-01

216

The soil reference shrinkage curve  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A recently proposed model showed how a clay shrinkage curve is transformed to the soil shrinkage curve at the soil clay content higher than a critical one. The objective of the present work was to generalize this model to the soil clay content lower a critical one. I investigated (i) the reference shrinkage curve, that is, one without cracks; (ii) the superficial layer of aggregates, with changed pore structure compared with the intraaggregate matrix; and (iii) soils with su...

Chertkov, V. Y.

2014-01-01

217

Sustainable Soil Water Management Systems  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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...

Basch, G.; Kassam, A.; Friedrich, T.; Santos, F. L.; Gubiani, P. I.; Calegari, A.; Reichert, J. M.; Dos Santos, D. R.

2012-01-01

218

Soil bioassay: Problems and approaches  

Science.gov (United States)

The methodological and organizational problems of the practical application of soil bioassay to monitor the state of soils for environmental, agricultural, and sanitary-epidemiological purposes are analyzed. To improve the efficiency of the integral valuation of soil toxicity, soil bioassay should be performed with a set of organisms (sensors) representing the major trophic levels of the ecosystems, i.e., producers, consumers, and decomposers.

Terekhova, V. A.

2011-02-01

219

Decomposition of soil organic matter  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The climate is changing and with it the capacity of soils to store carbon in all likelihood, since there is strong evidence that decomposition increases with increasing temperature. The soil contains about twice as much carbon as the atmosphere, so decreasing soil carbon will increase atmospheric CO? concentrations proportionally more, further contributing to temperature increase. Different types of soil carbon may respond differently to climate change. A central theory in explaining temper...

Wetterstedt, Martin

2010-01-01

220

Mathematical simulation of soil cloddiness  

Directory of Open Access Journals (Sweden)

Full Text Available A theoretical model was developed to predict soil clod size distribution attained after tillage so that it can be taken as initial state of soil for following erosion processes. The model was developed previously for rocks. The model predicts soil fragmentation resulting from multiple crack formation due to statistically uniform stresses. Peculiarities inherent to soils in view of their plastic properties are discussed. Comparison between calculated results and published experimental data demonstrates a satisfactory agreement.

V.Y.Chertkov

1995-09-01

 
 
 
 
221

Soil carbon determination by thermogravimetrics  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Determination of soil constituents and structure has a vital role in agriculture generally. Methods for the determination of soil carbon have in particular gained greater currency in recent times because of the potential that soils offer in providing offsets for greenhouse gas (CO2-equivalent) emissions. Ideally, soil carbon which can also be quite diverse in its makeup and origin, should be measureable by readily accessible, affordable and reliable means. Loss-on-ignition is still a widely u...

Mcbratney, Alex B.; Budiman Minasny; Robert Pallasser

2013-01-01

222

Soil carbon: Resisting climate change  

Science.gov (United States)

Increasing temperatures are expected to increase decomposition rates in soils, potentially reducing ecosystem carbon storage. Research now indicates that -- in a tropical montane forest -- soil carbon stocks are unaffected by higher temperatures despite substantially increased rates of CO2 release from the soil.

Hartley, Iain P.

2014-09-01

223

The Science of Soil Textures  

Science.gov (United States)

Off-road motorcycle racing and ATV riding. Gardening and fishing. What do these high-adrenaline and slower-paced pastimes have in common? Each requires soil, and the texture of that soil has an effect on all of them. In the inquiry-based lessons described here, students work both in the field or laboratory and in the classroom to collect soil

Bigham, Gary

2010-01-01

224

Soil-Transmitted Helminth Infections  

Science.gov (United States)

Soil-transmitted helminth infections Fact sheet N°366 Updated April 2014 Key facts Soil-transmitted helminth infections are caused by different species ... eggs present in human faeces, which contaminate the soil in areas where sanitation is poor. Approximately two ...

225

SOIL SURVEY GEOGRAPHIC DATABASE (SSURGO)  

Science.gov (United States)

This data set is a digital soil survey and is the most detailed level of soil geographic data developed by the National Cooperative Soil Survey. This data set consists of georeferenced digital map data and computerized attribute data. The map data are in a 7.5 minute quadrangle ...

226

Container Soil-Water Reactions.  

Science.gov (United States)

Presented is an activity that illustrates the relationship between the soil found in containers and soil in the ground including the amount of air and water found in each. Sponges are used to represent soil. Materials, procedures, and probable results are described. (KR)

Spomer, L. Art; Hershey, David R.

1990-01-01

227

Biochar addition impacts soil microbial community in tropical soils  

Science.gov (United States)

Studies on the effect of biochar on soil microbial activity and community structure in tropical areas are scarce. In this study we report the effect of several types of biochar (sewage sludge biochar, paper mill waste biochar, miscanthus biochar and pinewood biochar) in the soil microbial community of two tropical soils, an Acrisol and an Oxisol. In addition we study the effect of the presence or absence of earthworms in soil microbial community. Soil microbial community was more strongly affected by biochar than by the presence or absence of macrofauna.

Paz-Ferreiro, Jorge; Fu, Shenglei; Méndez, Ana; Gascó, Gabriel

2014-05-01

228

Soils. Transparency Masters.  

Science.gov (United States)

This document is a collection of 43 overhead transparency masters to be used as teaching aids in a course of study involving soils such as geology, agronomy, hydrology, earth science, or land use study. Some transparencies are in color. Selected titles of transparencies may give the reader a better understanding of the graphic content. Titles are:…

Clemson Univ., SC. Vocational Education Media Center.

229

Soil - Research and monitoring  

Apr 3, 2009 ... To search for all Defra-funded science and research projects please visit: ... \\policies such as CAP cross compliance and agri-environment schemes. ... \\National information and databases are necessary for Defra to determine the \\best ... Increase the accessibility of soil data to other users by ensuring the ...

230

Basic Mechanics of Soils  

Science.gov (United States)

This site, produced by the University of the West of England, Bristol, contains undergraduate level interactive resource on soils. This covers everything from analysis of stress and strain, to strength, stiffness and material behaviors. The site offers many different aspects which can easily fit a fairly broad survey on these topics.

2008-10-08

231

How soil shapes the landscape  

Science.gov (United States)

There has been an increase in interest in quantitative modelling of soil genesis, which can provide prediction of environmental changes through numerical models. Modelling soil formation is a difficult task because soil itself is highly complex with interactions between water, inorganic materials and organic matter. This paper will provide a review on the research efforts of modelling soil genesis, their connection with landscape models and the inexorable genesis of the IUSS soil landscape modelling working group. Quantitative modelling soil formation using mechanistic models have begun in the 1980s such as the 'soil deficit' model by Kirkby (1985), Hoosbeek & Bryant's pedodynamic model (1992), and recently the SoilGen model by Finke (2008). These profile models considered the chemical reactions and physical processes in the soil at the horizon and pedon scale. The SoilGen model is an integration of sub-models, such as water and solute movement, heat transport, soil organic matter decomposition, mineral dissolution, ion exchange, adsorption, speciation, complexation and precipitation. The model can calculate with detail the chemical changes and materials fluxes in a profile and has been successfully applied. While they can simulate soil profile development in detail, there is still a gap how the processes act in the landscape. Meanwhile research in landscape formation in geomorphology is progressing steadily over time, slope development models model have been developed since 1970s (Ahnert, 1977). Soil was also introduced in a landscape, however soil processes are mainly modelled through weathering and transport processes (Minasny & McBratney 1999, 2001). Recently, Vanwalleghem et al. (2013) are able to combine selected physical, chemical and biological processes to simulate a full 3-D soil genesis in the landscape. Now there are research gaps between the 2 approaches: the landscape modellers increasingly recognise the importance of soil and need more detailed soil processes, and the soil profile modellers need to consider material fluxes at the landscape scale. The IUSS working group (WG) on modelling of soil and landscape evolution has been recently proposed, accepted and established. The WG tries to engage scientists (landscape and pedon scale modellers, critical zone scientists, palaeopedologists, process-quantifying pedologists, and others) to work actively together towards a better soil-landscape model. Some aspects of the work include (i) improving ways to generate boundary conditions (climate, vegetation, human impacts) along the timeline, both at landscape and pedon scale; (ii) better model validation and its consequences for data collection; (iii) finding a more efficient simulation algorithms (iv) an inventory of the (mis-)match between present and needed process coverage to answer societal questions on soil behavior under global change.

Minasny, Budiman; Finke, Peter; Vanwalleghem, Tom Tom; Stockmann, Uta; McBratney, Alex

2014-05-01

232

Soil warming alters microbial substrate use in alpine soils.  

Science.gov (United States)

Will warming lead to an increased use of older soil organic carbon (SOC) by microbial communities, thereby inducing C losses from C-rich alpine soils? We studied soil microbial community composition, activity, and substrate use after 3 and 4 years of soil warming (+4 °C, 2007-2010) at the alpine treeline in Switzerland. The warming experiment was nested in a free air CO2 enrichment experiment using depleted (13)CO2 (?(13)C = -30‰, 2001-2009). We traced this depleted (13)C label in phospholipid fatty acids (PLFA) of the organic layer (0-5 cm soil depth) and in C mineralized from root-free soils to distinguish substrate ages used by soil microorganisms: fixed before 2001 ('old'), from 2001 to 2009 ('new') or in 2010 ('recent'). Warming induced a sustained stimulation of soil respiration (+38%) without decline in mineralizable SOC. PLFA concentrations did not reveal changes in microbial community composition due to soil warming, but soil microbial metabolic activity was stimulated (+66%). Warming decreased the amount of new and recent C in the fungal biomarker 18:2?6,9 and the amount of new C mineralized from root-free soils, implying a shift in microbial substrate use toward a greater use of old SOC. This shift in substrate use could indicate an imbalance between C inputs and outputs, which could eventually decrease SOC storage in this alpine ecosystem. PMID:24106016

Streit, Kathrin; Hagedorn, Frank; Hiltbrunner, David; Portmann, Magdalena; Saurer, Matthias; Buchmann, Nina; Wild, Birgit; Richter, Andreas; Wipf, Sonja; Siegwolf, Rolf T W

2014-04-01

233

Soil washing results for mixed waste pond soils at Hanford  

International Nuclear Information System (INIS)

Soil washing technology was assessed as a means for remediating soil contaminated with mixed wastes primarily composed of heavy metals and radionuclides. The soils at the US Department of Energy's Hanford Site are considered suitable for soil washing because of their relatively low quantities of silt and clay. However, in a limited number of soil washing experiments using soils from different locations in the north pond of the 300 Area, the degree of decontamination achieved for the coarse fraction of the soil varied considerably. Part of this variation appears to be due to the presence of a discrete layer of contaminated sediment found in some of the samples. 7 refs., 2 figs., 4 tabs

234

Soil strength and soil pore characteristics for direct-drilled and ploughed soils  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Direct drilling has often been reported to increase density and strength and to affect pore continuity and tortuosity of the upper soil layers. In this study these aspects were studied for three texturally differing soils 4–6 years after initiation of continuous trials with direct drilling and mouldboard ploughing. The soils studied were a coarse sandy soil (Korntved, 5% clay), a sandy loam (Ballum, 8% clay) and a silty loam (Højer, 19% clay). The crop rotation at Korntved was spring barle...

Schjønning, P.; Rasmussen, K. J.

2000-01-01

235

Chemical evaluation of soil-solution in acid forest soils  

Science.gov (United States)

Soil-solution chemistry is commonly studied in forests through the use of soil lysimeters.This approach is impractical for regional survey studies, however, because lysimeter installation and operation is expensive and time consuming. To address these problems, a new technique was developed to compare soil-solution chemistry among red spruce stands in New York, Vermont, New Hampshire, Maine. Soil solutions were expelled by positive air pressure from soil that had been placed in a sealed cylinder. Before the air pressure was applied, a solution chemically similar to throughfall was added to the soil to bring it to approximate field capacity. After the solution sample was expelled, the soil was removed from the cylinder and chemically analyzed. The method was tested with homogenized Oa and Bs horizon soils collected from a red spruce stand in the Adirondack Mountains of New York, a red spruce stand in east-central Vermont, and a mixed hardwood stand in the Catskill Mountains of New York. Reproducibility, effects of varying the reaction time between adding throughfall and expelling soil solution (5-65 minutes) and effects of varying the chemical composition of added throughfall, were evaluated. In general, results showed that (i) the method was reproducible (coefficients of variation were generally soil exchange chemistry. Concentrations of expelled solutions varied with the concentrations of added throughfall; the lower the CEC, the more sensitive expelled solution concentrations were to the chemical concentrations of added throughfall. Addition of a tracer (NaBr) showed that the expelled solution was a mixture of added solution and solution that preexisted in the soil. Comparisons of expelled solution concentrations with concentrations of soil solutions collected by zero-tension and tension lysimetry indicated that expelled solution concentrations were higher than those obtained with either type of lysimeter, although there was less difference with tension lysimeters than zero-tension lysimeters. The method used for collection of soil solution should be taken into consideration whenever soil solution data are being interpreted.

Lawrence, G. B.; David, M. B.

1996-01-01

236

Bioavailability of radiocaesium in soil: parameterization using soil characteristics  

Energy Technology Data Exchange (ETDEWEB)

It has been shown that radiocaesium availability to plants strongly influenced by soil properties. For the best evaluation of TFs it necessary to use mechanistic models that predict radionuclide uptake by plants based on consideration of sorption-desorption and fixation-remobilization of the radionuclide in the soil as well as root uptake processes controlled by the plant. The aim of the research was to characterise typical Russian soils on the basis of the radiocaesium availability. The parameter of the radiocaesium availability in soils (A) has been developed which consist on radiocaesium exchangeability; CF -concentration factor which is the ratio of the radiocaesium in plant to that in soil solution; K{sub Dex} - exchangeable solid-liquid distribution coefficient of radiocaesium. The approach was tested for a wide range of Russian soils using radiocaesium uptake data from a barley pot trial and parameters of the radiocaesium bioavailability. Soils were collected from the arable horizons in different soil climatic zones of Russia and artificially contaminated by {sup 137}Cs. The classification of soils in terms of the radiocaesium availability corresponds quite well to observed linear relationship between {sup 137}Cs TF for barley and A. K{sub Dex} is related to the soil radiocaesium interception potential (RIP), which was found to be positively and strongly related to clay and physical clay (<0,01 mm) content. The {sup 137}Cs exchangeability were found to be in close relation to the soil vermiculite content, which was estimated by the method of Cs{sup +} fixation. It's shown radiocaesium availability to plants in soils under study can be parameterized through mineralogical soil characteristics: % clay and the soil vermiculite content. (author)

Syssoeva, A.A.; Konopleva, I.V. [Russian Institute of Agricultural Radiology and Agroecology, Obninsk (Russian Federation)

2004-07-01

237

Bioavailability of radiocaesium in soil: parameterization using soil characteristics  

International Nuclear Information System (INIS)

It has been shown that radiocaesium availability to plants strongly influenced by soil properties. For the best evaluation of TFs it necessary to use mechanistic models that predict radionuclide uptake by plants based on consideration of sorption-desorption and fixation-remobilization of the radionuclide in the soil as well as root uptake processes controlled by the plant. The aim of the research was to characterise typical Russian soils on the basis of the radiocaesium availability. The parameter of the radiocaesium availability in soils (A) has been developed which consist on radiocaesium exchangeability; CF -concentration factor which is the ratio of the radiocaesium in plant to that in soil solution; KDex - exchangeable solid-liquid distribution coefficient of radiocaesium. The approach was tested for a wide range of Russian soils using radiocaesium uptake data from a barley pot trial and parameters of the radiocaesium bioavailability. Soils were collected from the arable horizons in different soil climatic zones of Russia and artificially contaminated by 137Cs. The classification of soils in terms of the radiocaesium availability corresponds quite well to observed linear relationship between 137Cs TF for barley and A. KDex is related to the soil radiocaesium interception potential (RIP), which was found to be positively and strongly related to clay and physical clay (137Cs exchangeability were found to be in close relation to the soil vermiculite content, which was estimated by the method of Cs+ fixation. It's shown radiocaesium availability to plants in soils under study can be parameterized through mineralogical soil characteristics: % clay and the soil vermiculite content. (author)

238

Mine soil classification and mapping  

International Nuclear Information System (INIS)

This presentation covers the history of surface coal mining and reclamation methods and equipment for the pre-Federal law, interim-Federal law, and post-Federal law periods. It discusses the difficulties with traditional mine soil mapping methods on five soils series in Illinois. These methods fail to recognize the effects of compaction and methods to ameliorate compaction. The current status of mine soil mapping methods on eight soil series in Illinois are presented. Areas where additional work is needed and future potential difficulties are identified for mine soil mapping efforts

239

The role of biological soil crusts on soil moisture  

Science.gov (United States)

In water-limited ecosystems, water becomes the most important driver for plant productivity. In these systems, spatial distribution of water resources is not random but organized into a mosaic of water-depletion areas linked to water-accumulation areas. In other words, water is transferred from interplant patches that act as source areas to vegetation patches that act as sinks of this resource. Thus, structure and functioning of interplant patches have a decisive role in water redistribution and distribution patterns of vegetation. Soil surface in the interplant spaces of most arid and semiarid ecosystems is covered by biological soil crusts (BSCs). These organisms regulate water fluxes into and through soils and play major roles in local hydrological processes. In the last years, the role of these organisms in infiltration and runoff has gained increased importance and a better knowledge about their effects on these processes has been acquired. However, the role of BSCs in other important components of the water balance such as evaporation or soil moisture has been scarcely studied, so that their effects on these processes remain unknown. The objective of this work is to examine the influence of BSCs on soil moisture regimes in the top profile of the soil in two semiarid ecosystems of SE Spain with contrasting soil texture and where BSCs are well-represented. Soil moisture content at 0.03 and 0.10 m was monitored under two representative types of BSCs, a dark cyanobacteria-dominated BSC and a light-coloured lichen-dominated BSC, and in soils where these BSCs were removed by scraping, at both study sites. Our results show that, under high water conditions, removal of BSCs leads to a decrease in soil moisture compared to soils covered by BSCs. Decrease in soil moisture due to BSC removal namely affects moisture in the upper layer of the soil (0.03 m), but has little impact in deeper soil (0.10 m). Evaporation is also generally faster in soils with no BSCs than in soils covered by them. The type of BSC influences soil moisture in a different way depending on soil water conditions. Under high water content conditions, soil water loss is faster and soil moisture content lower under cyanobacterial than under lichen BSCs, due to higher infiltration promoted by lichens. On the contrary, under low water content conditions, lichen-crusted soils dry out faster and exhibit less moisture than cyanobacteria-crusted ones, attributed to the larger porosity and subsequent greater evaporative losses in lichen- than in cyanobacteria-crusted soils. We found higher moisture in coarse-textured soils than in fine-textured ones, despite the higher water retention capacity of the latter soils. More favourable conditions in the coarser soils, which had greater organic matter content, aggregate stability and were subject to less water stress due to its proximity to the coast, seems to contribute to this increased soil moisture content. BSCs therefore play an important role on the maintenance of water availability in the interplant spaces, thereby strongly affecting soil physical and biological processes, and the potential for emergence establishment and survival of plants in semiarid ecosystems.

Chamizo, S.; Cantón, Y.; Lázaro, R.; Rodriguez-Caballero, E.; Domingo, F.

2012-04-01

240

Salt movement in disturbed soils  

International Nuclear Information System (INIS)

A literature review is presented of information on salt movement in disturbed soils, particularly in soils that have been disturbed by pipeline construction. The review has two main objectives: to assess climatic and soil conditions under which salts will move out of the root zone in a disturbed soil and to determine the rate at which salts will move in disturbed soils. A literature base was established using computer database and library searches, and a number of studies were reviewed. Many studies, dealing specifically with salt movement over time in disturbed soils under climatic and salt conditions similar to those found in Alberta, are summarized in tabular form. Data found in the literature tend to be sparse and incomplete, making firm conclusions about rates of salt movement difficult. In the brown soil zone, 5 years may be sufficient time for sodium absorption ratio and electrical conductivity levels, elevated during construction, to return to pre-construction conditions in coarse to moderately coarse textured soils. In medium to moderately fine textured soils, 10-26 years may be required. In the dark brown soil zone, 5 years is marginal for return to pre-construction conditions. Data in the black soil zone are limited and results inconsistent. 37 refs., 3 figs., 4 tabs

 
 
 
 
241

Effects of environmental factors and soil properties on topographic variations of soil respiration  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Soil respiration rates were measured along different parts of a slope in (a) an evergreen forest with common brown forest soil and (b) a deciduous forest with immature soil. The effects of soil temperature, soil moisture and soil properties were estimated individually, and the magnitudes of these effects in the deciduous and evergreen forests were compared. In the evergreen forest with common brown forest soil, soil properties had the greatest effect on soil respiration rates, followed by soi...

Tamai, K.

2010-01-01

242

Dynamical soil-structure interactions: influence of soil behaviour nonlinearities  

International Nuclear Information System (INIS)

The interaction of the soil with the structure has been largely explored the assumption of material and geometrical linearity of the soil. Nevertheless, for moderate or strong seismic events, the maximum shear strain can easily reach the elastic limit of the soil behavior. Considering soil-structure interaction, the nonlinear effects may change the soil stiffness at the base of the structure and therefore energy dissipation into the soil. Consequently, ignoring the nonlinear characteristics of the dynamic soil-structure interaction (DSSI) this phenomenon could lead to erroneous predictions of structural response. The goal of this work is to implement a fully nonlinear constitutive model for soils into a numerical code in order to investigate the effect of soil nonlinearity on dynamic soil structure interaction. Moreover, different issues are taken into account such as the effect of confining stress on the shear modulus of the soil, initial static condition, contact elements in the soil-structure interface, etc. During this work, a simple absorbing layer method based on a Rayleigh/Caughey damping formulation, which is often already available in existing Finite Element softwares, is also presented. The stability conditions of the wave propagation problems are studied and it is shown that the linear and nonlinear behavior are very different when dealing with numerical dispersion. It is shown that the 10 points per wavelength rule, recommended in the literature for the elastic media is not sufficient for the nonlinear case. The implemented model is first numerically verified by comparing the results with other known numerical codes. Afterward, a parametric study is carried out for different types of structures and various soil profiles to characterize nonlinear effects. Different features of the DSSI are compared to the linear case: modification of the amplitude and frequency content of the waves propagated into the soil, fundamental frequency, energy dissipation in the soil and the response of the soil-structure system. Through these parametric studies we show that depending on the soil properties, frequency content of the soil response could change significantly due to the soil nonlinearity. The peaks of the transfer function between free field and outcropping responses shift to lower frequencies and amplification happens at this frequency range. Amplification reduction for the high frequencies and even de-amplification may happen for high level input motions. These changes influence the structural response. We show that depending on the combination of the fundamental frequency of the structure and the the natural frequency of the soil, the effect of soil-structure interaction could be significant or negligible. However, the effect of structure weight and rocking of the superstructure could change the results. Finally, the basin of Nice is used as an example of wave propagation on a heterogeneous nonlinear media and dynamic soil-structure interaction. The basin response is strongly dependent on the combination of soil nonlinearity, topographic effects and impedance contrast between soil layers. For the selected structures and soil profiles of this work, the performed numerical simulations show that the shift of the fundamental frequency is not a good index to discriminate linear from nonlinear soil behavior. (author)

243

Soil Carbon Sequestration in India  

International Nuclear Information System (INIS)

With a large land area and diverse ecoregions, there is a considerable potential of terrestrial/soil carbon sequestration in India. Of the total land area of 329 million hectares (Mha), 297 Mha is the land area comprising 162 Mha of arable land, 69 Mha of forest and woodland, 11 Mha of permanent pasture, 8 Mha of permanent crops and 58 Mha is other land uses. The soil organic carbon (SOC) pool is estimated at 21 Pg (petagram = Pg = 1 x 1015 g billion ton) to 30-cm depth and 63 Pg to 150-cm depth. The soil inorganic carbon (SIC) pool is estimated at 196 Pg to 1-m depth. The SOC concentration in most cultivated soils is less than 5 g/kg compared with 15 to 20 g/kg in uncultivated soils. Low SOC concentration is attributed to plowing, removal of crop residue and other biosolids, and mining of soil fertility. Accelerated soil erosion by water leads to emission of 6 Tg C/y. Important strategies of soil C sequestration include restoration of degraded soils, and adoption of recommended management practices (RMPs) of agricultural and forestry soils. Potential of soil C sequestration in India is estimated at 7 to 10 Tg C/y for restoration of degraded soils and ecosystems, 5 to 7 Tg C/y for erosion control, 6 to 7 Tg C/y for adoption of RMPs on agricultural soils, and 22 to 26 Tg C/y for secondary carbonates. Thus, total potential of soil C sequestration is 39 to 49 (44± 5) Tg C/y

244

Chelant soil-washing technology for metal-contaminated soil.  

Science.gov (United States)

We demonstrate here, in a pilot-scale experiment, the feasibility of ethylenediaminetetraacetate (EDTA)based washing technology for soils contaminated with potentially toxic metals. Acid precipitation coupled to initial alkaline toxic metal removal and an electrochemical advanced oxidation process were used for average recovery of 76 +/- 2% of EDTA per batch and total recycle of water in a closed process loop. No waste water was generated; solid wastes were efficiently bitumen-stabilized before disposal. The technology embodiment, using conventional process equipment, such as a mixer for soil extraction, screen for soil/gravel separation, filter chamber presses for soil/liquid and recycled EDTA separation and soil rinsing, continuous centrifuge separator for removal of precipitated metals and electrolytic cells for process water cleansing, removed up to 72%, 25% and 66% of Pb, Zn and Cd from garden soil contaminated with up to 6960, 3797 and 32.6 mg kg(-1) of Pb, Zn and Cd, respectively, in nine 60kg soil batches. Concentrations of Pb and Zn remaining in the remediated soil and bioaccessible from the simulated human intestinal phase soil were reduced by 97% and 96% and were brought under the level of determination for Cd. In the most cost-effective operation mode, the material and energy costs of remediation amounted to 50.5 Euros ton(-1) soil and the total cost to 299 Euros ton(-1). PMID:24701937

Voglar, David; Lestan, Domen

2014-01-01

245

Soil salinity decreases global soil organic carbon stocks.  

Science.gov (United States)

Saline soils cover 3.1% (397 million hectare) of the total land area of the world. The stock of soil organic carbon (SOC) reflects the balance between carbon (C) inputs from plants, and losses through decomposition, leaching and erosion. Soil salinity decreases plant productivity and hence C inputs to the soil, but also microbial activity and therefore SOC decomposition rates. Using a modified Rothamsted Carbon model (RothC) with a newly introduced salinity decomposition rate modifier and a plant input modifier we estimate that, historically, world soils that are currently saline have lost an average of 3.47 tSOC ha(-1) since they became saline. With the extent of saline soils predicted to increase in the future, our modelling suggests that world soils may lose 6.8 Pg SOC due to salinity by the year 2100. Our findings suggest that current models overestimate future global SOC stocks and underestimate net CO2 emissions from the soil-plant system by not taking salinity effects into account. From the perspective of enhancing soil C stocks, however, given the lower SOC decomposition rate in saline soils, salt tolerant plants could be used to sequester C in salt-affected areas. PMID:22959898

Setia, Raj; Gottschalk, Pia; Smith, Pete; Marschner, Petra; Baldock, Jeff; Setia, Deepika; Smith, Jo

2013-11-01

246

Determination of soil hydraulic properties using the soil pedostructure concept  

Science.gov (United States)

The observed soil water properties such as Field Capacity, Permanent Wilting Point, Water Potential and Hydraulic Conductivity are expressions of the internal soil structure and are all connected to Water Matric Potential. Our research describes these properties in a context of a new concept of the internal hierarchal soil structure and the tension that exists inside the soil matrix due to the presence of clay particles. This concept will be demonstrated using laboratory experiments of simultaneous and continuous measurements of the soil water potential curve and of the shrinkage and swelling curves. The soil shrinkage curve has been used to explain the hydraulic and functional properties of soil with its assembly of swelling aggregates according to the conceptual pedostructure model. In that model two water pools held in two distinguished macro- and micro-porosity are described in addition to specific characteristics of the primary peds such air entry point, maximum swelling, and plasmic porosity. The water potential will be calculated according to these water pools. In this context, the empirical agronomical soil physical properties like wilting point and field capacity, will be defined relative to a particular hydrostructural state of the soil rather than to a hypothetical soil water potential. These properties could then be accurately determined starting from the measured shrinkage curve determined by retractometry.

Braudeau, E.; Mohtar, R. H.

2003-04-01

247

Radon in soil gas  

International Nuclear Information System (INIS)

This paper presents the results of a technology review conducted to identify and organize the range of options for measuring radon in soil gas as a means to evaluate radon exposure potential in buildings. The main focus of the review includes identifying the following: Measurement of objectives - the specific parameter(s) that each technology is designed to measure( e.g., soil gas concentration, flux density, etc.); Equipment needs -commercial availability of systems and/or components, specifications for fabricated components; Procedural information - documented elements of field and laboratory methodology and quality assurance; Underlying assumptions - conceptual and mathematical models utilized to convert analytical outcomes to estimators of radon. Basic technologies and field data were examined from a generic perspective (e.g., the common denominators of passive detectors, hollow sampling probes, flux monitors)( as well as specific configurations developed by individual investigators (e.g., sample volume, depth) to develop the basis for separating analytical uncertainties form sampling uncertainties

248

Soil physical properties on Venezuelan steeplands: Applications to soil conservation planning  

International Nuclear Information System (INIS)

This paper presents a framework to support decision making for soil conservation on Venezuelan steeplands. The general approach is based on the evaluation of two important land qualities: soil productivity and soil erosion risk, both closely related to soil physical properties. Soil productivity can be estimated from soil characteristics such as soil air-water relationships, soil impedances and soil fertility. On the other hand, soil erosion risk depends basically on soil hydrologic properties, rainfall aggressiveness and terrain slope. Two indexes are obtained from soil and land characteristics: soil productivity index (PI) and erosion risk index (ERI), each one evaluates the respective land quality. Subsequently, a matrix with these two qualities shows different land classes as well as soil conservation priorities, conservation requirements and proposed land uses. The paper shows also some applications of the soil productivity index as an approach to evaluate soil loss tolerance for soil conservation programs on tropical steeplands. (author)

249

Predicting Soil-Air and Soil-Water Transport Properties During Soil Vapor Extraction  

DEFF Research Database (Denmark)

Increased application of in-situ technology for control and removal of volatile organic compounds (VOC) in the subsurface has made the understanding of soil physical properties and their impact upon contaminant transport even more important. Knowledge of contaminant transport is important when designing and operating remediation systems. Simple and accurate models for estimating soil properties from soil parameters that are easy to measure are useful in connection with preliminary remedial investigations and evaluation of remedial technologies. In this work simple models for predicting transport properties of undisturbed soil from more easily measurable soil properties are developed. The importance of soil properties with respect to contaminant migration during remediation by soil vapor extraction (SVE) in the unsaturated zone was investigated using numerical simulations.

Poulsen, Tjalfe

1997-01-01

250

Food, soil, and agriculture  

International Nuclear Information System (INIS)

The growing pressures on the world's land resources will result in problems requiring a major research effort.The first group of problems relates to increased soil degradation. The research to alleviate this will have to incorporate not only physical and biological solutions, but also pay much more attention to the socio-economic context in which the conservation programmes need to succeed.The second major area for research on land resource is to make better use of low-capacity or problem soils.This could be by reducing the existing limitations, such as changing physical or chemical characteristics of the soil, or by developing plants and production techniques which reduce the detrimental effects of constraints. Example of these are acidity, salinity, and aluminium toxicity. Finally the broadest and more important area is that of research to enable more intensive use of better-quality land. Research topics here may relate to optimal plant nutrient management, soil moisture management, and developing cultivation techniques with minimum commercial energy requirements. Making plants more productive will involve research aimed at increasing photosynthetic efficiency, nitrogen fixation, disease and pest resistance, improved weed control, and bio-engineering to adjust plant types to maximize production potentials. Improved rotational systems for the achievement of many of the above goals will become increasingly important, as the potential problems or inappropriate cultivattential problems or inappropriate cultivation practices become evident. In conclusion, food supplies of the world could meet the rapidly rising demands that are made on them, if agriculture receives sufficient attention and resources. Even with most modern development, land remains the base for agriculture, and optimal use of the world's land resources is thus crucial for future agricultural production

251

Soils, Pores, and NMR  

Science.gov (United States)

Within Cluster A, Partial Project A1, the pore space exploration by means of Nuclear Magnetic Resonance (NMR) plays a central role. NMR is especially convenient since it probes directly the state and dynamics of the substance of interest: water. First, NMR is applied as relaxometry, where the degree of saturation but also the pore geometry controls the NMR signature of natural porous systems. Examples are presented where soil samples from the Selhausen, Merzenhausen (silt loams), and Kaldenkirchen (sandy loam) test sites are investigated by means of Fast Field Cycling Relaxometry at different degrees of saturation. From the change of the relaxation time distributions with decreasing water content and by comparison with conventional water retention curves we conclude that the fraction of immobile water is characterized by T1 low-field and ultra-fast pulse imaging. Also first results on the imaging of soil columns measured by SIP in Project A3 are given. Haber-Pohlmeier, S., S. Stapf, et al. (2010). "Waterflow Monitored by Tracer Transport in Natural Porous Media Using MRI." Vadose Zone J.: submitted. Haber-Pohlmeier, S., S. Stapf, et al. (2010). "Relaxation in a Natural soil: Comparison of Relaxometric Imaging, T1 - T2 Correlation and Fast-Field Cycling NMR." The Open Magnetic Resonance Journal: in print. Pohlmeier, A., S. Haber-Pohlmeier, et al. (2009). "A Fast Field Cycling NMR Relaxometry Study of Natural Soils." Vadose Zone J. 8: 735-742. Stingaciu, L. R., A. Pohlmeier, et al. (2009). "Characterization of unsaturated porous media by high-field and low-field NMR relaxometry." Water Resources Research 45: W08412

Pohlmeier, Andreas; Haber-Pohlmeier, Sabina; Haber, Agnes; Sucre, Oscar; Stingaciu, Laura; Stapf, Siegfried; Blümich, Bernhard

2010-05-01

252

Soil column leaching of pesticides.  

Science.gov (United States)

In this review, I address the practical and theoretical aspects of pesticide soil mobility.I also address the methods used to measure mobility, and the factors that influence it, and I summarize the data that have been published on the column leaching of pesticides.Pesticides that enter the unsaturated soil profile are transported downwards by the water flux, and are adsorbed, desorbed, and/or degraded as they pass through the soil. The rate of passage of a pesticide through the soil depends on the properties of the pesticide, the properties of the soil and the prevailing environmental conditions.Because large amounts of many different pesticides are used around the world, they and their degradates may sometimes contaminate groundwater at unacceptable levels.It is for this reason that assessing the transport behavior and soil mobility of pesticides before they are sold into commerce is important and is one indispensable element that regulators use to assess probable pesticide safety. Both elementary soil column leaching and sophisticated outdoor lysimeter studies are performed to measure the leaching potential for pesticides; the latter approach more reliably reflects probable field behavior, but the former is useful to initially profile a pesticide for soil mobility potential.Soil is physically heterogeneous. The structure of soil varies both vertically and laterally, and this variability affects the complex flow of water through the soil profile, making it difficult to predict with accuracy. In addition, macropores exist in soils and further add to the complexity of how water flow occurs. The degree to which soil is tilled, the density of vegetation on the surface, and the type and amounts of organic soil amendments that are added to soil further affect the movement rate of water through soil, the character of soil adsorption sites and the microbial populations that exist in the soil. Parameters that most influence the rate of pesticide mobility in soil are persistence (DT50) of the pesticide, and its sorption/desorption(Koc) characteristics. These parameters may vary for the same pesticide from geographic site-to-site and with soil depth. The interactions that normally occur between pesticides and dissolved organic matter (DOM) or WDC are yet other factors that may complicate pesticide leaching behavior.The soil mobility of pesticides is normally tested both in the laboratory and in the field. Lab studies are initially performed to give researchers a preliminary appraisal of the relative mobility of a pesticide. Later, field lysimeter studies can be performed to provide more natural leaching conditions that emulate the actual field use pattern. Lysimeter studies give the most reliable information on the leaching behavior of a pesticide under field conditions, but these studies are time-consuming and expensive and cannot be performed everywhere. It is for this reason that the laboratory soil column leaching approach is commonly utilized to profile the mobility of a pesticide,and appraise how it behaves in different soils, and relative to other pesticides.Because the soil structure is chemically and physically heterogenous, different pesticide tests may produce variable DT50 and Koc values; therefore, initial pesticide mobility testing is undertaken in homogeneously packed columns that contain two or more soils and are eluted at constant flow rates. Such studies are done in duplicate and utilize a conservative tracer element. By fitting an appropriate mathematical model to the breakthrough curve of the conservative tracer selected,researchers determine key mobility parameters, such as pore water velocity, the column-specific dispersion coefficient, and the contribution of non equilibrium transport processes. Such parameters form the basis for estimating the probable transport and degradation rates that will be characteristic of the tested pesticide. Researchers also examine how a pesticide interacts with soil DOM and WDC, and what contribution from facilitated transport to mobility is made as a result of the effects of

Katagi, Toshiyuki

2013-01-01

253

Contaminated soil stabilization demonstration  

International Nuclear Information System (INIS)

Long-term herbicide control along with a shotcrete cover was constructed at the Hanford Site in May 1991. The cover system allows for maintenance-free containment of contaminants by preventing wind and water transport of contaminants from the soil surface, preventing plant uptake of contaminants, and minimizing water infiltration through the soil column. The cover is composed of two parts: a commercial nonwoven geotextile material impregnated with trifluralin, and a >5-centimeter top cover of shotcrete containing polyethylene fibers. The herbicide-impregnated geotextile functions to prevent plant root growth into contaminated soil if any holes or cracks develop in the shotcrete layer. The herbicide component, trifluralin, is mixed into polymer nodules that degrade slowly over many years, thus releasing trifluralin slowly over time. The shotcrete topcover was sprayed using a sludge pump and air compressor to form a hard, impenetrable surface that prevents wind erosion and reduces water infiltration through the contaminated materials underneath. The benefits of the cover system are expected to last 20 to 30 years. 2 refs., 4 figs

254

Solos urbanos Urban soils  

Directory of Open Access Journals (Sweden)

Full Text Available A forte pressão provocada pela expansão urbana desordenada sobre os recursos naturais, principalmente os solos, tem provocado danos, muitas vezes de difícil reparo. A grande concentração populacional em centros urbanos cada vez maiores tem dirigido a atenção de diferentes profissionais para o recurso solo, no sentido de entender sua dinâmica para minimizar sua degradação. No entanto, a falta de conhecimento sobre as propriedades, bem como sobre a aptidão dos solos sob uso urbano tem provocado o seu mau uso, resultando em processos como compactação, erosão, deslizamentos e inundações, assim como poluição com substâncias orgânicas, inorgânicas e patógenos, aumentando os custos do desenvolvimento afetando toda a sociedade. Neste sentido, este texto discute como o conhecimento pedológico pode diminuir os efeitos negativos provocados pelo processo de urbanização.The strong pressure caused by the disordered urban expansion over the natural resources, mainly the soils, has caused damages, many times difficult to repair. The great population concentration in urban centers getting larger and larger has been driving the attention of different professionals to soil resource, in the sense of understanding its dynamics to minimize its degradation. The lack of knowledge related to the soils properties and capability promote their inappropriate use, resultig in degrading processes as compaction, erosion, sliding, floods, and organic, inorganic and patogenic pollution, increasing the cost of development and affecting the whole society. This text discusses how pedologic knowledge can reduce the negative effects caused by the urbanization process.

Fabrício de Araújo Pedron

2004-10-01

255

Soil and terrestial indicators  

International Nuclear Information System (INIS)

Long-lived radionuclides 90Sr, 137Cs and 239,240Pu in soil are analysed in the vicinity of nuclear power stations every four years. Both vertical disribution and the total amount of radionuclides per unit of area are determined from the samples. The results of surveys carried out at Loviisa in 1983 and at Olkiluoto in 1984 are presented here. The total deposition determined by soil samples had decreased slightly since the previous soil studies and was, on average, 630 Bq m-2 of 90Sr, 1800 Bq m-2137Cs and 30 Bq m-2239,240Pu. To follow up short-lived radionuclides in deposition, an indicator organism, hair moss, is analysed four times a year in the vicinity of nuclear power stations. Hair moss principally reflects the fall-out from nuclear weapon tests. Small amounts of 60Co released from power stations was also detectable. Both an indicator and a step in the food chain leading to man, pasture grass was analysed in the vicinity of nuclear power stations twice during the growing season. The concentrations of 137Cs were very low, and no 131I was detected. The results for hair moss and pasture grass at Loviisa from 1980-1985 and from 1981-1985 at Olkiluoto are given

256

Soils and organic sediments  

International Nuclear Information System (INIS)

The organic component of soils is basically made up of substances of an individual nature (fats, waxes, resins, proteins, tannic substances, and many others), and humic substances (Kononova, 1966). These are complex polymers formed from breakdown products of the chemical and biological degradation of plant and animal residues. They are dark coloured, acidic, predominantly aromatic compounds ranging in molecular weight from less than one thousand to tens of thousands (Schnitzer, 1977). They can be partitioned into three main fractions:(i) Humic acid, which is soluble in dilute alkaline solution, but can be precipitated by acidification of the alkaline extract.(ii) Fulvic acid, which is soluble in alkaline solution, but is also soluble on acidification.(iii) Humin that cannot be extracted from the soil or sediment by dilute acid or alkaline solutions. It has mostly been assumed that the humic and fulvic acid components of the soil are part of the mobile, or 'active' component, and the humin component is part of the 'passive' component. Other types of organic sediments are likely to contain chemical breakdown products of plant material, plant fragments and material brought in from outside sources. The outside material can be contemporaneous with sediment deposition, can be older material, or younger material incorporated into the sediment long after deposition. Recognition of 'foreign' material is essential for dating, but is not an easy task. Examples of separation techniques for humic and non humic components are evaluated for their efficiency

257

Soil Properties Database of Spanish Soils Volume III.- Extremadura  

International Nuclear Information System (INIS)

The soil vulnerability determines the sensitivity of the soil after an accidental radioactive contamination due to Cs-13 7 and Sr-90. The Departamento de Impacto Ambiental de la Energia of CIEMAT is carrying out an assessment of the radiological vulnerability of the different Spanish soils found on the Iberian Peninsula. This requires the knowledge of the soil properties for the various types of existing soils. In order to achieve this aim, a bibliographical compilation of soil profiles has been made to characterize the different soil types and create a database of their properties. Depending on the year of publication and the type of documentary source, the information compiled from the available bibliography is very heterogeneous. Therefore, an important effort has been made to normalize and process the information prior to its incorporation to the database. This volume presents the criteria applied to normalized and process the data as well as the soil properties of the various soil types belonging to the Comunidad Autonoma de Extremadura. (Author) 50 refs

258

Forest soil disturbance intervals inferred from soil charcoal radiocarbon dates  

International Nuclear Information System (INIS)

Forest soil disturbance intervals are usually too long to measure using plot-based studies, and thus they are poorly understood. The mean soil disturbance interval (MSDI) in an old-growth forest on the west coast of Vancouver Island was estimated from radiocarbon dates of charcoal from organic and mineral soil horizons. Two assumptions are required to estimate the MSDI: charcoal from forest fires is deposited within the organic horizon and eventually mixed into deeper mineral horizons by soil disturbances, and the probability of soil disturbance is spatially homogeneous and affected only by the time since the last fire or the last soil disturbance. The MSDI is then estimated by the rate at which the proportion of undisturbed sample sites (determined by the proportion of sites with charcoal from the most recent fire in the organic horizon) decreases with increasing time since the last fire. Soil charcoal evidence of time since fire was determined at 83 sites using 141 radiocarbon dates. The estimated MSDI was greater on slopes (ca. 2010 years) than on terraces (ca. 920 years). The long periods between soil disturbances, especially on slopes, are consistent with other evidence from the study area that suggests infrequent tree uprooting is the predominant mode of soil disturbance. (author)

259

Soil vapor extraction of JP-4 jet fuel contaminated soils  

International Nuclear Information System (INIS)

This paper presents findings and lessons learned from the investigation, pilot, design, and remedial action phases of a soil vapor extraction (SVE) project. Soil vapor extraction was performed on JP-4 jet fuel contaminated soils at two fire training pits at Luke AFB, Arizona. The site was used for fire training exercises on a quarterly basis from 1973 to as late as 1990. Petroleum wastes were originally used for fire training exercised but this practice was discontinued during 1973. Five soil borings were drilled and sampled in each of the two fire training pits during the investigations

260

Soil Properties Database of Spanish Soils. Volume XV.- Aragon  

International Nuclear Information System (INIS)

The soil vulnerability determines the sensitivity of the soil after an accidental radioactive contamination due to Cs-137 and Sr-90. The Departamento de Impacto Ambiental de la Energia of CIEMAT is carrying out an assessment of the radiological vulnerability of the different Spanish soils found on the Iberian Peninsula. This requires the knowledge of the soil properties for the various types of existing soils. In order to achieve this aim, a bibliographical compilation of soil profiles has been made to characterize the different soil types and create a database of their properties. Depending on the year of publication and the type of documentary source, the information compiled from the available bibliography is very heterogeneous. Therefore, an important effort has been made to normalize and process the information prior to its incorporation to the database. This volume presents the criteria applied to normalize and process the data as well as the soil properties of the various soil types belonging to the Comunidad Autonoma of Aragon. (Author) 47 refs

 
 
 
 
261

GLOBE Videos: Soil Characterization - Soil Temperature (10:54 min)  

Science.gov (United States)

This video describes how to select a soil temperature study site, and demonstrates the procedure students use when taking soil temperature measurements in the field. The resource includes a video and a written transcript, and is supported by the Soil Temperature Protocol in the GLOBE Teacher Guide. This is one of five videos about soils in the 24-part instructional video series describing scientific protocols used by GLOBE (Global Learning and Observation to Benefit the Environment) a worldwide, hands-on, K-12 school-based science education program.

262

Forest soil disturbance intervals inferred from soil charcoal radiocarbon dates  

Energy Technology Data Exchange (ETDEWEB)

Forest soil disturbance intervals are usually too long to measure using plot-based studies, and thus they are poorly understood. The mean soil disturbance interval (MSDI) in an old-growth forest on the west coast of Vancouver Island was estimated from radiocarbon dates of charcoal from organic and mineral soil horizons. Two assumptions are required to estimate the MSDI: charcoal from forest fires is deposited within the organic horizon and eventually mixed into deeper mineral horizons by soil disturbances, and the probability of soil disturbance is spatially homogeneous and affected only by the time since the last fire or the last soil disturbance. The MSDI is then estimated by the rate at which the proportion of undisturbed sample sites (determined by the proportion of sites with charcoal from the most recent fire in the organic horizon) decreases with increasing time since the last fire. Soil charcoal evidence of time since fire was determined at 83 sites using 141 radiocarbon dates. The estimated MSDI was greater on slopes (ca. 2010 years) than on terraces (ca. 920 years). The long periods between soil disturbances, especially on slopes, are consistent with other evidence from the study area that suggests infrequent tree uprooting is the predominant mode of soil disturbance. (author)

Gavin, D.G. [Univ. of Illinois, Dept. of Plant Biology, Urbana Illinois (United States)]. E-mail: dgavin@life.uiuc.edu

2003-12-01

263

Quantifying Shrink Swell Capacity of Soil Using Soil Moisture Isotherms  

Science.gov (United States)

Vertisols, soils instinctively known for their expansive clays that cause them to have a high shrink swell potential, cover 2.4% of the earths ice-free land. In the United States these expansive soils can cause upwards of 6 billion in damages to pavements, foundations, and utility lines annually (Brady & Weil, 2010). Because of this, it is especially important that a soils ability to shrink and swell is well characterized when making engineering decisions. One traditional method for measuring a soil's expansive potential, the Coefficient of Linear Extensibility (COLE), can take weeks to months to complete (Grossman et al., 1968; Schafer and Singer, 1976b). Use of soil moisture isotherms, or the Soil Moisture Characteristic Curve (SMCC), in recent research has shown that the slope of the SMCC is related to a soils swelling potential (McKeen, 1992). The goal of this research is to evaluate the robustness of the relationship between the SMCC and COLE for a set of well-characterized test soils with COLE ranging from 0 to 0.176. If expansive potential can be reliably predicted from the SMCC, then data from recently developed automatic soil moisture isotherm generators could be used to characterize expansive potential with a fraction of the time and effort necessary for traditional techniques.

Rivera, L. D.; Cobos, D. R.; Campbell, C. S.; Morgan, C.

2013-12-01

264

A soil quality index for reclaimed mine soils.  

Science.gov (United States)

The quality of soils found in mines is low if they do not receive any reclamation treatment; yet, to the authors’ knowledge, there are still no equations to evaluate the quality of metal-contaminated mine soils after the application of the most widely used reclamation treatments (planting vegetation and amending with wastes). Therefore, the purposes of the present study were 1) to propose a method for developing soil quality indexes (SQIs); 2) to develop the SQIs for 2 types of mine soils (settling pond and mine tailing) reclaimed by planting trees, amending with wastes, or both; and 3) to assess the quality of these soils under field conditions. The results obtained after the use of an SQI developed for reclaimed mine soils through the selection of an SQI with a factor analysis and the totaling of the scores of the selected variables revealed that this method is a valid tool for developing SQIs. Applying this index with reclaimed mine soils showed that the untreated sites had a very low quality and that the treatment that most improved the soils was amending with wastes (sewage sludges and paper mill residues). The authors recommend the periodic addition of sewage sludges and paper mill residues to degraded sites as they increase the quality of soils, but the effects decrease over time. PMID:23787921

Asensio, Verónica; Guala, S D; Vega, Flora A; Covelo, Emma F

2013-10-01

265

Soil Properties Database of Spanish Soils Volume I.-Galicia  

International Nuclear Information System (INIS)

The soil vulnerability determines the sensitivity of the soil after an accidental radioactive contamination due to Cs-13 7 and Sr-90. The Department de Impacto Ambiental de la Energia of CIEMAT is carrying out an assessment of the radiological vulnerability of the different Spanish soils found on the Iberian Peninsula. This requires the knowledge of the soil properties for the various types of existing soils. In order to achieve this aim. a bibliographical compilation of soil profiles has been made to characterize the different soil types and create a database of their properties. Depending on the year of publication and the type of documentary)' source, the information compiled from the available bibliography is very heterogeneous. Therefore, an important effort has been made to normalize and process the information prior to its incorporation to the database. This volume presents the criteria applied to normalize and process the data as well as the soil properties of the various soil types belonging to the Comunidad Autonoma de Galicia

266

Soil Moisture Data Assimilation in Soil Water Flow Modeling  

Science.gov (United States)

Soil water flow modeling has multiple applications. This modeling is based on simplifications stemming from both conceptual uncertainty and lack of detailed knowledge about parameters. Modern soil moisture sensors can provide detailed information about changes in soil water content in time and with depth. This information can be used for data assimilation in soil water flow modeling. The ensemble Kalman filter appears to be an appropriate method for that. Earlier we demonstrated ensemble simulations of soil water flow by using sets of pedotransfer functions (empirical relationships between soil hydraulic properties and soil basic properties, such as particle size distribution, bulk density, organic carbon content, etc.). The objective of this work was to apply the data assimilation with the ensemble Kalman filter to soil water flow modeling, using soil water content monitoring with TDR probes and an ensemble of soil water flow models parameterized with different pedotransfer functions. Experiments were carried out at the Bekkevoort site, Belgium. Sixty time domain reflectometry (TDR) probes with two rods) were installed along the trench in loamy soil at 12 locations with 50-cm horizontal spacing at five depths (15, 35, 55, 75, and 95 cm). Water content and weather parameters were monitored for one year with 15 min frequency. Soil water flow was simulated using the HYDRUS6 software. Mean daily means of water contents at the observation depths were the measurements used in data assimilation. Eighteen pedotransfer functions for water retention and one for hydraulic conductivity were applied to generate ensembles to evaluate the uncertainty in simulation results, whereas the replicated measurements at each of measurement depths were used to characterize the uncertainty in data. Data assimilation appeared to be very efficient. Even assimilating measurements at a single depth provided substantial improvement in simulations at other observation depths. Results on selecting one best depth or two best depths will be presented. Best depths appear to be different depending on whether simulations are carried out to estimate soil water dynamics in root zone or to estimate infiltration losses beyond this zone. Soil moisture sensor data assimilation in soil flow modeling allows one to avoid multiparametric calibration and correct simulation on the go which can be beneficial in many applications, Using pedotransfer functions in ensemble Kalman filter results in the effective data assimilation in soil water flow modeling.

Pachepsky, Y. A.; Guber, A.; Jacques, D.; Pan, F.; van Genuchten, M.; Cady, R. E.; Nicholson, T. J.

2010-12-01

267

Fuzzy Representation of Soil Erosion  

Science.gov (United States)

Fuzzy representation is a productive method to explain the natural processes so that it is near to linguistic form and it is also applicable to estimate the environmental processes in where the uncertainty in information is high. As models proposed to estimate soil erosion also have uncertainties and fuzzy inference system is more flexible in describing the relationship between soil erosion and other factor, especially in managing data and model uncertainties. in the research, it is used simplified model of revised Universal Soil Loss Equation (RUSLE) to estimate soil erosion in dry lands of Kashan area in Central Iran . Then to discover the systematic (IF-Then) rules in soil erosion process, we used inductive reasoning method to discover rules of the causing agents of erosion such as rainfall erosivity, topography factors, soil erodibility , then highly supported rules converted to fuzzy rules. It is resulted that the application of fuzzy inference system for erosion evaluation is applicable in regional level.

Komaki, Ch. B.; Kainz, W.; Alavi Panah, S. K.; Matinfar, H. R.

2009-04-01

268

Modelling soil organic carbon concentration of mineral soils in arable lands using legacy soil data  

DEFF Research Database (Denmark)

Soil organic carbon (SOC) concentration is an essential factor in biomass production and soil functioning. SOC concentration values are often obtained by prediction but the prediction accuracy depends much on the method used. Currently, there is a lack of evidence in the soil science literature as to the advantages and shortcomings of the different commonly used prediction methods. Therefore, we compared and evaluated the merits of the median approach, analysis of covariance, mixed models and random forests in the context of prediction of SOC concentrations of mineral soils under arable management in the A-horizon. Three soil properties were used in all of the developed models: soil type, physical clay content (particle size <0.01 mm) and A-horizon thickness. We found that the mixed model predicted SOC concentrations with the smallest mean squared error (0.05%2), suggesting that a mixed-model approach is appropriate if the study design has a hierarchical structure as in our scenario. We used the Estonian National Soil Monitoring data on arable lands to predict SOC concentrations of mineral soils. Subsequently, the model with the best prediction accuracy was applied to the Estonian digital soil map for the case study area of Tartu County where the SOC predictions ranged from 0.6 to 4.8%. Our study indicates that predictions using legacy soil maps can be used in national inventories and for up-scaling estimates of carbon concentrations from county to country scales.

Suuster, E; Ritz, Christian

2012-01-01

269

Soil-solution speciation of Cd as affected by soil characteristics in unpolluted and polluted soils.  

Science.gov (United States)

Total metal content by itself is insufficient as a measure to indicate actual environmental risk. Understanding the mobility of heavy metals in the soil and their speciation in the soil solution is of great importance for accurately assessing environmental risks posed by these metals. In a first explorative study, the effects of general soil characteristics on Cd mobility were evaluated and expressed in the form of empirical formulations. The most important factors influencing mobility of Cd proved to be pH and total soil content. This may indicate that current legislation expressing the requirement for soil sanitation in Flanders (Belgium) as a function of total soil content, organic matter, and clay does not successfully reflect actual risks. Current legal frameworks focusing on total content, therefore, should be amended with criteria that are indicative of metal mobility and availability and are based on physicochemical soil properties. In addition, soil-solution speciation was performed using two independent software packages (Visual Minteq 2.23 and Windermere Humic Aqueous model VI [WHAM VI]). Both programs largely were in agreement in concern to Cd speciation in all 29 soils under study. Depending on soil type, free ion and the organically complexed forms were the most abundant species. Additional inorganic soluble species were sulfates and chlorides. Minor species in solution were in the form of nitrates, hydroxides, and carbonates, the relative importance of which was deemed insignificant in comparison to the four major species. PMID:15779747

Meers, Erik; Unamuno, Virginia; Vandegehuchte, Michiel; Vanbroekhoven, Karolien; Geebelen, Wouter; Samson, Roeland; Vangronsveld, Jaco; Diels, Ludo; Ruttens, Ann; Du Laing, Gijs; Tack, Filip

2005-03-01

270

Dependence of soil respiration on soil temperature and soil moisture in successional forests in Southern China  

Science.gov (United States)

The spatial and temporal variations in soil respiration and its relationship with biophysical factors in forests near the Tropic of Cancer remain highly uncertain. To contribute towards an improvement of actual estimates, soil respiration rates, soil temperature, and soil moisture were measured in three successional subtropical forests at the Dinghushan Nature Reserve (DNR) in southern China from March 2003 to February 2005. The overall objective of the present study was to analyze the temporal variations of soil respiration and its biophysical dependence in these forests. The relationships between biophysical factors and soil respiration rates were compared in successional forests to test the hypothesis that these forests responded similarly to biophysical factors. The seasonality of soil respiration coincided with the seasonal climate pattern, with high respiration rates in the hot humid season (April-September) and with low rates in the cool dry season (October-March). Soil respiration measured at these forests showed a clear increasing trend with the progressive succession. Annual mean (?? SD) soil respiration rate in the DNR forests was (9.0 ?? 4.6) Mg CO2-C/hm2per year, ranging from (6.1 ?? 3.2) Mg CO2-C/hm2per year in early successional forests to (10.7 ?? 4.9) Mg CO2-C/hm2 per year in advanced successional forests. Soil respiration was correlated with both soil temperature and moisture. The T/M model, where the two biophysical variables are driving factors, accounted for 74%-82% of soil respiration variation in DNR forests. Temperature sensitivity decreased along progressive succession stages, suggesting that advanced-successional forests have a good ability to adjust to temperature. In contrast, moisture increased with progressive succession processes. This increase is caused, in part, by abundant respirators in advanced-successional forest, where more soil moisture is needed to maintain their activities. ?? 2006 Institute of Botany, Chinese Academy of Sciences.

Tang, X. -L.; Zhou, G. -Y.; Liu, S. -G.; Zhang, D. -Q.; Liu, S. -Z.; Li, J.; Zhou, C. -Y.

2006-01-01

271

ASPECTS REGARDING THE METHODS OF SOIL AERATION  

Directory of Open Access Journals (Sweden)

Full Text Available Aspects regarding the methods of soil aeration. Soil aeration is a process to be carried out continuously the gas exchange between soil and atmosphere. The process is done mainly by the movement of water inside and outside him. There are three major gases in the soil (nitrogen,oxygen and carbon dioxide. Soil air composition differs from that of air by higher CO2 content (0,3 to 0,5%. The air in the soil is very important for the dynamics of soil. Soil aeration is accomplished through mass flow and diffusion. In this paper the authors present these methods of soil aeration

A. UNGURA?U

2011-03-01

272

Heavy metals in Estonian soils  

International Nuclear Information System (INIS)

The article discusses the concentrations of Pb, U, Th and other elements in the humus horizon of Estonian soils. These concentrations are rather variable, first and foremost reflecting the concentrations of elements in the parent rock of the soils and are pretty near to the calculated average of the Earth's soils. The origin of the positive anomalies of these elements is mostly natural, although partly it is also technogenic. (author). 3 figs

273

Biodegradation of dimethylsilanediol in soils.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The biodegradation potential of [14C]dimethylsilanediol, the monomer unit of polydimethylsiloxane, in soils was investigated. Dimethylsilanediol was found to be biodegraded in all of the tested soils, as monitored by the production of 14CO2. When 2-propanol was added to the soil as a carbon source in addition to [14C]dimethylsilanediol, the production of 14CO2 increased. A method for the selection of primary substrates that support cometabolic degradation of a target compound was developed. B...

Sabourin, C. L.; Carpenter, J. C.; Leib, T. K.; Spivack, J. L.

1996-01-01

274

Indicators for Monitoring Soil Biodiversity  

DEFF Research Database (Denmark)

The European Union (EU) soil policy is described in general terms in the EU Soil Strategy (EC 2006a) and the legally binding elements of the policy are proposed in the draft Soil Framework Directive (SFD; EC 2006b). In these documents, eight main threats to soil were identified by the EU Commission. The EU FP6 project ENVASSO (Environmental Assessment of Soil for Monitoring) had the aim to design a single, integrated and operational set of EU-wide criteria and indicators to provide the basis for a harmonised comprehensive soil and land information system for monitoring in Europe. Here, a proposal is made for a set of suitable indicators for monitoring the decline in soil biodiversity (Bispo et al. 2007). These indicators were selected both from a literature review and an inventory of national monitoring programmes. Decline in soil biodiversity was defined as the reduction of forms of life living in soils (both in terms of quantity and variety) and of related functions, causing a deterioration of one or more soil functions or ecosystem services. Whereas literature review allows the identification of about 100 possible indicators, the inventory of existing monitoring networks shows that few indicators are actually measured.   For monitoring application it was considered in ENVASSO that only three key indicators per soil stress were practical. For indicating biodiversity decline it was difficult to arrive at a small set of indicators due to the complexity of soil biota and functions. Therefore, three stringent criteria were applied: an indicator should 1) have a standardized sampling and/or measuring methodology; 2) be complementary to other indicators; and 3) be easy to interpret at both scientific and policy levels.

Bispo, A.; Cluzeau, D.

2009-01-01

275

Stochastic modeling of soil salinity  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A minimalist stochastic model of primary soil salinity is proposed, in which the rate of soil salinization is determined by the balance between dry and wet salt deposition and the intermittent leaching events caused by rainfall events. The long term probability density functions of salt mass and concentration are found by reducing the coupled soil moisture and salt mass balance equation to a single stochastic differential equation driven by multiplicative Poisson noise. The novel analytical s...

Suweis, Samir; Rinaldo, Andrea; Zee, Sjoerd; Edoardo, Daly; Maritan, Amos; Porporato, Amilcare

2010-01-01

276

Stochastic Modeling of Soil Salinity  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A minimalist stochastic model of primary soil salinity is proposed, in which the rate of soil salinization is determined by the balance between dry and wet salt deposition and the intermittent leaching events caused by rainfall events. The long term probability density functions of salt mass and concentration are found by reducing the coupled soil moisture and salt mass balance equation to a single stochastic differential equation driven by multiplicative Poisson noise. The ...

Suweis, S.; Rinaldo, A.; Zee, S. E. A. T. M.; Daly, E.; Maritan, A.; Porporato, A.

2012-01-01

277

Myxobacters from arid mexican soil.  

Science.gov (United States)

Myxobacters were found to be common inhabitants of the arid soils from the Monterrey, Nuevo Leon, Mexico, area. Thirteen species of the genera Myxococcus, Archangium, Cystobacter, Stigmatella, Polyangium, and Chondromyces were isolated on a mineral salts agar supplemented with bakers' yeast and filter paper. Greater species diversity per soil sample was found in the region receiving 400 to 800 mm of annual rainfall as compared with soils from an area having only 200 to 400 mm of rainfall. PMID:16345178

Brockman, E R

1976-10-01

278

Antibiotic Production by Soil Actinomycetes  

Science.gov (United States)

Students attempt to identify Streptomycetes with antibiotic properties in local soil samples. The purpose of this investigation is to try to discover Actinomycetes from local soil samples that have antibiotic properties. The use of known species of Streptomycetes that produce antibiotics can be easily seen as they produce zones of inhibition on a lawn of bacteria; the antibiotic activity from local soil samples is variable and takes many samples to find a few that produce zones of inhibition.

BEGIN:VCARD VERSION:2.1 FN:John William Goudie N:William Goudie;John ORG:Kalamazoo Area Math and Science Center REV:2005-04-08 END:VCARD

1995-06-30

279

In-situ vitrification of soil  

International Nuclear Information System (INIS)

A method of vitrifying soil at or below a soil surface location. Two or more conductive electrodes are inserted into the soil for heating of the soil mass between them to a temperature above its melting temperature. Materials in the soil, such as buried radioactive waste, can thereby be effectively immobilized. (author)

280

SITE TECHNOLOGY CAPSULE: BIOGENESIS SOIL WASHING TECHNOLOGY  

Science.gov (United States)

Soil washing technologies are designed to transfer contaminants from soil to a liquid phase. The BloGenesis? soil washing technology uses a proprietary surfactant solution to transfer organic contaminants from soil to wastewater. The surfactant used in the soil washing process wa...

 
 
 
 
281

In-situ vitrification of soil  

Science.gov (United States)

A method of vitrifying soil at or below a soil surface location. Two or more conductive electrodes are inserted into the soil for heating of the soil mass between them to a temperature above its melting temperature. Materials in the soil, such as buried waste, can thereby be effectively immobilized.

Brouns, Richard A. (Kennewick, WA); Buelt, James L. (Richland, WA); Bonner, William F. (Richland, WA)

1983-01-01

282

Airflow dispersion in unsaturated soil.  

Science.gov (United States)

Dispersion data is abundant for water flow in the saturated zone but is lacking for airflow in unsaturated soil. However, for remediation processes such as soil vapour extraction, characterization of airflow dispersion is necessary for improved modelling and prediction capabilities. Accordingly, gas-phase tracer experiments were conducted in five soils ranging from uniform sand to clay at air-dried and wetted conditions. The disturbed soils were placed in one-dimensional stainless steel columns, with sulfur hexafluoride used as the inert tracer. The tested interstitial velocities were typical of those present in the vicinity of a soil vapour extraction well, while wetting varied according to the water-holding capacity of the soils. Results gave dispersivities that varied between 0.42 and 2.6 cm, which are typical of values in the literature. In air-dried soils, dispersion was found to increase with the pore size variability of the soil. For wetted soils, particle shape was an important factor at low water contents, while at high water contents, the proportion of macroporous space filled with water was important. The relative importance of diffusion decreased with increasing interstitial velocity and water content and was, in general, found to be minor compared to mechanical mixing across all conditions studied. PMID:16246460

Gidda, T; Cann, D; Stiver, W H; Zytner, R G

2006-01-01

283

Soil Moisture Monitoring for Agriculture  

International Science & Technology Center (ISTC)

Elaboration of a Modern Technology for Operational Agrometeorological Soil Moisture Monitoring Spring Wheat, Yield and Disease Damage Forecasting and Recommendations for Plant Protection on the Kazakhstan Territory

284

Soil and terrestrial biology studies  

International Nuclear Information System (INIS)

Soil and terrestrial biology studies focused on developing an understanding of the uptake of gaseous substances from the atmosphere by plants, biodegradation of oil, and the movement of Pu in the terrestrial ecosystems of the southeastern United States. Mathematical models were developed for SO2 and tritium uptake from the atmosphere by plants; the uptake of tritium by soil microorganisms was measured; and the relationships among the Pu content of soil, plants, and animals of the Savannah River Plant area were studied. Preliminary results are reported for studies on the biodegradation of waste oil on soil surfaces

285

Connecting Soils and Glacial Geology  

Science.gov (United States)

The goal of this activity is to provide students an opportunity to connect soil science to surficial geology by using a Soil Surveys. By the end of the activity, students should be able to use a Soil Survey to identify and interpret landforms and surficial features. This activity can be adapted to variety of process (ex. eolian deposits, glacial deposits, bedrock weathering, etc.). County-level soil surveys are available in both paper and online formats for the majority of the United States. Designed for a geomorphology course Has minimal/no quantitative component

Dolliver, Holly

286

Análise espacial dos fatores da equação universal de perda de solo em área de nascentes / Spatial analysis of universal soil loss equation factors of a watershed area relief  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese O objetivo deste trabalho foi avaliar a perda de solo de área de nascentes da Microbacia do Córrego do Tijuco, SP. Foi utilizada a análise espacial dos fatores da equação universal da perda de solo (EUPS), em integração com análise de componentes principais e geoestatística. A perda de solo média, e [...] stimada para a área, foi de 118,5 Mg ha?1 por ano, considerada alta. Próximo à zona urbana, houve alta interação dos fatores erosividade da chuva e práticas conservacionistas, o que evidencia grande perda de solo, em razão da concentração da água proveniente da camada impermeabilizada urbana, com alta velocidade de escoamento. Nos divisores de águas, a atuação da erodibilidade foi proeminente, em contraste com o fator topográfico. Foram observadas áreas com atuação conjunta destes fatores, inclusive em locais de inclinação suave, porém com alto potencial natural de erosão. A interação das análises multivariadas e geoestatística permite a estratificação da área, identifica locais com propriedades específicas quanto à perda de solo, e espacializa os fatores do processo erosivo e suas interações ao longo do relevo. Abstract in english The objective of this work was to evaluate the soil loss of an area of springs in the Microbacia do Córrego do Tijuco, SP, Brazil. Spatial analysis of the universal soil loss equation (USLE) factors, in integrated with principal component analysis and geostatistics, was used. The average soil loss e [...] stimated for the area was 118.5 Mg ha?1 per year, which is considered high. Near the urban zone, there was a high interaction of rainfall erosivity and conservation practices, which shows a high?soil loss, due to the concentration of water from impervious urban layer with a high?flow velocity. In the water partings, the performance of erodibility was prominent, in contrast to the topographic factor. Areas were observed with joint action of these factors, including sites with gentle slope, but with a high, natural potential of erosion. The interaction of multivariate and geostatistic analyses allows the area stratification, identifies locations with specific properties as to soil loss, and spatialises the erosion factors and their interactions along the landscape.

Daniela Popim, Miqueloni; Célia Regina Paes, Bueno; Antonio Sergio, Ferraudo.

1358-13-01

287

Análise espacial dos fatores da equação universal de perda de solo em área de nascentes / Spatial analysis of universal soil loss equation factors of a watershed area relief  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese O objetivo deste trabalho foi avaliar a perda de solo de área de nascentes da Microbacia do Córrego do Tijuco, SP. Foi utilizada a análise espacial dos fatores da equação universal da perda de solo (EUPS), em integração com análise de componentes principais e geoestatística. A perda de solo média, e [...] stimada para a área, foi de 118,5 Mg ha?1 por ano, considerada alta. Próximo à zona urbana, houve alta interação dos fatores erosividade da chuva e práticas conservacionistas, o que evidencia grande perda de solo, em razão da concentração da água proveniente da camada impermeabilizada urbana, com alta velocidade de escoamento. Nos divisores de águas, a atuação da erodibilidade foi proeminente, em contraste com o fator topográfico. Foram observadas áreas com atuação conjunta destes fatores, inclusive em locais de inclinação suave, porém com alto potencial natural de erosão. A interação das análises multivariadas e geoestatística permite a estratificação da área, identifica locais com propriedades específicas quanto à perda de solo, e espacializa os fatores do processo erosivo e suas interações ao longo do relevo. Abstract in english The objective of this work was to evaluate the soil loss of an area of springs in the Microbacia do Córrego do Tijuco, SP, Brazil. Spatial analysis of the universal soil loss equation (USLE) factors, in integrated with principal component analysis and geostatistics, was used. The average soil loss e [...] stimated for the area was 118.5 Mg ha?1 per year, which is considered high. Near the urban zone, there was a high interaction of rainfall erosivity and conservation practices, which shows a high?soil loss, due to the concentration of water from impervious urban layer with a high?flow velocity. In the water partings, the performance of erodibility was prominent, in contrast to the topographic factor. Areas were observed with joint action of these factors, including sites with gentle slope, but with a high, natural potential of erosion. The interaction of multivariate and geostatistic analyses allows the area stratification, identifies locations with specific properties as to soil loss, and spatialises the erosion factors and their interactions along the landscape.

Daniela Popim, Miqueloni; Célia Regina Paes, Bueno; Antonio Sergio, Ferraudo.

288

Estimation of soil-soil solution distribution coefficient of radiostrontium using soil properties  

International Nuclear Information System (INIS)

We propose a new approach for estimation of soil-soil solution distribution coefficient (Kd) of radiostrontium using some selected soil properties. We used 142 Japanese agricultural soil samples (35 Andosol, 25 Cambisol, 77 Fluvisol, and 5 others) for which Sr-Kd values had been determined by a batch sorption test and listed in our database. Spearman's rank correlation test was carried out to investigate correlations between Sr-Kd values and soil properties. Electrical conductivity and water soluble Ca had good correlations with Sr-Kd values for all soil groups. Then, we found a high correlation between the ratio of exchangeable Ca to Ca concentration in water soluble fraction and Sr-Kd values with correlation coefficient R=0.72. This pointed us toward a relatively easy way to estimate Sr-Kd values

289

Saxton soil remediation project  

International Nuclear Information System (INIS)

The Saxton Nuclear Experimental Facility (SNEF) consists of a 23-MW(thermal) pressurized light water thermal reactor located in south central Pennsylvania. The Saxton Nuclear Experimental Corporation (SNEC), a wholly owned subsidiary of the General Public Utilities (GPU) Corporation, is the licensee for the SNEF. Maintenance and decommissioning activities at the site are conducted by GPU Nuclear, also a GPU subsidiary and operator of the Three Mile Island and Oyster Creek nuclear facilities. The remediation and radioactive waste management of contaminated soils is described

290

Radioisotopes in soil fertility and soil pollution research  

International Nuclear Information System (INIS)

Radioisotopes from nuclear reactors are very useful research tool for agricultural scientists. The availability of radioisotopes like 32P, 65Zn, 54Mn, etc. made it possible for the researchers to explore investigations on soil fertility, plant macro- and micronutrients. Heavy metal radioisotopes like 115mCd, 51Cr, 75Se, etc. play a significant role in soil pollution research. (author)

291

New perspectives on the soil erosion-soil quality relationship  

International Nuclear Information System (INIS)

The redistribution of soil has a profound impact on its quality (defined as its ability to function within its ecosystem and within adjacent ecosystems) and ultimately on its productivity for crop growth. The application of 137Cs-redistribution techniques to the study of erosion has yielded major new insights into the soil erosion-soil quality relationship. In highly mechanized agricultural systems, tillage erosion can be the dominant cause of soil redistribution; in other agroecosystems, wind and water erosion dominate. Each causal factor results in characteristic landscape-scale patterns of redistribution. In landscapes dominated by tillage redistribution, highest losses occur in shoulder positions (those with convex downslope curvatures); in water-erosion-dominated landscapes, highest losses occur where slope gradient and length are at a maximum. Major impacts occur through the loss of organically-enriched surface material and through the incorporation of possibly yield-limiting subsoils into the rooting zone of the soil column. The potential impact of surface soil losses and concomitant subsoil incorporation on productivity may be assessed by examining the pedological nature of the affected soils and their position in the landscape. The development of sound conservation policies requires that the soil erosion-quality relationship be rigorously examined in the full range of pedogenic environments, and future applications of the 137Cs technique hold considerable promise for providing this comprehensive global database. (author)

292

Pedotransfer functions estimating soil hydraulic properties using different soil parameters  

DEFF Research Database (Denmark)

Estimates of soil hydraulic properties using pedotransfer functions (PTF) are useful in many studies such as hydrochemical modelling and soil mapping. The objective of this study was to calibrate and test parametric PTFs that predict soil water retention and unsaturated hydraulic conductivity parameters. The PTFs are based on neural networks and the Bootstrap method using different sets of predictors and predict the van Genuchten/Mualem parameters. A Danish soil data set (152 horizons) dominated by sandy and sandy loamy soils was used in the development of PTFs to predict the Mualem hydraulic conductivity parameters. A larger data set (1618 horizons) with a broader textural range was used in the development of PTFs to predict the van Genuchten parameters. The PTFs using either three or seven textural classes combined with soil organic mater and bulk density gave the most reliable predictions of the hydraulic properties of the studied soils. We found that introducing measured water content as a predictor generally gave lower errors for water retention predictions and higher errors for conductivity predictions. The best of the developed PTFs for predicting hydraulic conductivity was tested against PTFs from the literature using a subdata set of the data used in the calibration. The test showed that the developed PTFs gave better predictions (lower errors) than the PTFs from the literature. This is not surprising since the developed PTFs are based mainly on hydraulic conductivity data near saturation and sandier soils than the PTFs from the literature.

BØrgesen, Christen Duus; Iversen, Bo VangsØ

2008-01-01

293

Soil fauna and soil functions: a jigsaw puzzle  

Directory of Open Access Journals (Sweden)

Full Text Available Terrestrial ecologists and soil modelers have traditionally portrayed the inhabitants of soil as a black box labeled as "soil fauna" or "decomposers or detritivores” assuming that they just merely recycle the deposited dead plant material. Soil is one of the most diverse habitats on Earth and contains one of the most diverse assemblages of living organisms; however, the opacity of this world has severely limited our understanding of their functional contributions to soil processes and to ecosystem resilience. Traditional taxonomy, based on morphological and anatomical aspects, is becoming replaced by rapid processing molecular techniques (e.g. with marker gene-based approaches. However, this may be impracticable in many ecological studies and consequently, the majority of the current knowledge, still contributes little to our understanding of their role in ecosystem functioning. Over the years, different workers have produced several ‘functional classifications’ based on the body width, feeding regime, certain behavioral and reproductive aspects and ecological niches of soil organisms. Unfortunately, the information available is severely restricted to ‘major’ groups. A better physiological and metabolic understanding of when and how a complex community of soil organisms access nutrients, alter their environment and in turn, affect soil processes, will allow a more realistic quantitative evaluation of their ecological roles in the biogeochemical cycles. Here, I review the applicability of the available approaches, highlight future research challenges and propose a dynamic conceptual framework that could improve our ability to solve this functional puzzle.

MariaJ.I.Briones

2014-04-01

294

2-Day Investigating Soil Samples: observing and identifying soils  

Science.gov (United States)

This activity is designed for a primary classroom (outdoors & indoors) investigation where students collect and investigate soil samples and describe the soils, looking for similarities and differences. Students develop a method of recording the data colleted and can present the information gathered.

295

What Makes Soil? Learning About Our Local Soils  

Science.gov (United States)

This activity is a field/classroom activity where students collect soil samples, form inquiry questions, devise a sorting method, make observations of the contents, record information, share information, and draw conclusions about their findings. Students will generate other inquiry questions related to soil for future learning opportunities.

Van Kekerix, Susan

296

ECOLOGICAL SOIL SCREENING LEVELS FOR SOIL INVERTEBRATES AND PLANTS  

Science.gov (United States)

Ecological Soil Screening Levels (Eco-SSLs) are being developed for 24 inorganic and inorganic chemicals for soil invertebrates and plants using procedures developed by a Task Group of the USEPA Eco-SSL Work Group. The Eco-SSL Work Group is a collaboration among USEPA, DoD, DOE, ...

297

Soil Chapter-Soils as Sponges: How Much Water does Soil Hold?  

Science.gov (United States)

Students determine the moisture content of a sponge after squeezing the water out of the sponge, and allowing water to evaporate from the sponge. Students also measure the amount of water that has evaporated from the soil samples. This learning resource is part of the Soils chapter of the GLOBE Teacher's Guide, and is supported by the GLOBE soils protocols. GLOBE (Global Learning and Observation to Benefit the Environment) is a worldwide, hands-on, K-12 school-based science education program.

298

Soil sampling for environmental contaminants  

International Nuclear Information System (INIS)

The Consultants Meeting on Sampling Strategies, Sampling and Storage of Soil for Environmental Monitoring of Contaminants was organized by the International Atomic Energy Agency to evaluate methods for soil sampling in radionuclide monitoring and heavy metal surveys for identification of punctual contamination (hot particles) in large area surveys and screening experiments. A group of experts was invited by the IAEA to discuss and recommend methods for representative soil sampling for different kinds of environmental issues. The ultimate sinks for all kinds of contaminants dispersed within the natural environment through human activities are sediment and soil. Soil is a particularly difficult matrix for environmental pollution studies as it is generally composed of a multitude of geological and biological materials resulting from weathering and degradation, including particles of different sizes with varying surface and chemical properties. There are so many different soil types categorized according to their content of biological matter, from sandy soils to loam and peat soils, which make analytical characterization even more complicated. Soil sampling for environmental monitoring of pollutants, therefore, is still a matter of debate in the community of soil, environmental and analytical sciences. The scope of the consultants meeting included evaluating existing techniques with regard to their practicability, reliability and applicability to different purposes, developing strategies of representative soil sampling for cases not yet considered by current techniques and recommending validated techniques applicable to laboratories in developing Member States. This TECDOC includes a critical survey of existing approaches and their feasibility to be applied in developing countries. The report is valuable for radioanalytical laboratories in Member States. It would assist them in quality control and accreditation process

299

Thermal stability of soils and detectability of intrinsic soil features  

Science.gov (United States)

Soils are products of long term pedogenesis in ecosystems. They are characterized by a complex network of interactions between organic and inorganic constituents, which influence soil properties and functions. However, the interrelations cannot easily be determined. Our search for unifying principles of soil formation focuses on water binding. This approach was derived from water-dependent soil formation. It considers the importance of water binding in theories about the origin of genes, in the structural arrangement and functionality of proteins, and in the co-evolution of organism species and the biosphere during the history of earth. We used thermogravimetry as a primary experimental technique. It allows a simple determi-nation of bound water together with organic and inorganic components in whole soil samples without a special preparation. The primary goal was to search for fingerprinting patterns using dynamics of thermal mass losses (TML) caused by water vaporization from natural soils, as a reference base for soil changes under land use. 301 soil samples were collected in biosphere reserves, national parks and other areas as-sumingly untouched by human activity in Siberia, North and South America, Antarctica, and in several long term agricultural experiments. The results did not support the traditional data evaluation procedures used in classical differ-ential thermogravimetry. For example, peak positions and amplitudes did not provide useful information. In contrast, using thermal mass losses (TML) in prefixed smaller, e.g. 10 °C temperature intervals allowed the determination of the content of carbon, clay, nitrogen and carbonates with high accuracy. However, this approach was applicable for soils and neither for soil-like carbon containing mineral substrates without pedogenetic origin, nor for plant residues or soils containing ashes, cinder, or charcoal. Therefore, intrinsic soil regulation processes are discussed as a possible factor causing applicability of thermogravimetry for soil property determination. Despite of the extreme diversity of individual substances in soils, the thermal decay can be predicted with simple mathematical models. For example, the sum of mass losses in the large temperature interval from 100 °C to 550 °C (known from organic matter determination by ignition mass loss in past) can be predicted using TML in two small temperature intervals: 130 - 140 °C and 320 - 330 °C. In this case, the coefficient of determination between measured and calculated results reached an R2 above 0.97. Further, we found close autocorrelations between thermal mass losses in different temperature intervals. They refer to interrelations between evaporation of bound water and thermal decay of organo-mineral complexes in soils less affected by human influence. In contrast, deviations from such interrelations were found under extreme environmental conditions and in soils under human use. Those results confirm current knowledge about influence of clay on both water binding and organic matter accumulation during natural soil formation. Therefore, these interrelations between soil components are discussed as intrinsic features of soils which open the opportunity for experimental distinction of natural soils from organic and inorganic materials which do not have pedogenetic origin.

Siewert, Christian; Kucerik, Jiri

2014-05-01

300

Soil fungi as indicators of pesticide soil pollution  

Directory of Open Access Journals (Sweden)

Full Text Available Soil fungi, with their pronounced enzymic activity and high osmotic potential, represent a significant indicator of negative effects of different pesticides on the agroecosystem as a whole. In that respect, a trial was set up on the alluvium soil type with the aim to investigate the effect of different herbicides (Simazine, Napropamid, Paraquat, fungicides (Captan and Mancozeb and insecticides (Fenitrothion and Dimethoate on a number of soil fungi under apple trees. The number of soil fungi was determined during four growing seasons by an indirect method of dilution addition on the Czapek agar. The study results indicate that the fungi belong to the group of microorganisms that, after an initial sensible response to the presence of pesticides in the soil, very rapidly establish normal metabolism enabling them even to increase their number. The fungicides and insecticides applied were found to be particularly effective in that respect.

Mandi? Leka

2005-01-01

 
 
 
 
301

Soil properties related to 60Co bioavailability in tropical soils  

International Nuclear Information System (INIS)

This work presents the results of field experiments to obtain soil to plants Transfer factor (TF) for 60Co in reference plants cultivated in Ferralsol, Acrisol and Nitisol. These soils represent the majority of Brazilian agricultural area. Values of TF varied from 0.001 to 0.05 for corn and from 0.001 to 0.81 for cabbage. Results of 60Co TF were discussed in relation to the physical and chemical properties of the soils and 60Co geochemical partition. The sequential chemical extraction showed that more than 40% of the 60Co present in the soils are associated to manganese oxides. These results will provide regional values for parameters used in the environmental radiological modeling aiming to optimize the planning of emergency interventions or the waste management related to tropical soils. (author)

302

Soil Redox Potential as a Control of Soil Total Gaseous Mercury Fluxes in Background Soils  

Science.gov (United States)

The purpose of our study was to examine how environmental parameters influence the surface atmosphere exchange of gaseous mercury in background soils of western Maryland. The parameters included soil temperature, redox potential, and volumetric water content. We also wanted to determine if soil pore air total gaseous mercury (TGM) concentrations were influencing atmospheric exchange. All parameters were measured at four depths below the soil surface, at the Oe - A soil horizon interface, A - E soil horizon interface, 5 cm into the E horizon, and 10 cm into the E horizon. Three plots were delineated in a forested area and three in a cleared area at the Piney Reservoir Ambient Air Monitoring Station (PRAAMS) in western Maryland. TGM fluxes were measured with a dynamic flux chamber and soil pore air concentrations were measured with our newly developed soil pore TGM sampling method. Plots were sampled for soil pore air TGM concentrations and TGM flux every third week from July 2009 through June 2010. The other parameters were measured every 10 minutes semi-continuously for the same period. Soil pore air TGM concentrations were significantly higher in the forested area (mean = 2.14 ng m-3) than the cleared area (mean = 1.62 ng m-3) (p=0.0001). Soil pore air TGM was significantly higher in the high organic content Oe layer for the forested site (p determined a net of deposition of ~0.4 ug m-2 to the soils at the cleared site from July to December 2009. From March to July 2010, there was a net emission of ~3.4 ug m-2 from the cleared area. We also used the model to estimate that the soils at the forested site emitted ~0.1 ug m-2 from July to December 2009 and ~2.3 ug m-2 from March to July 2010. More measurements of TGM flux and soil redox are needed in other areas to further validate the use of soil redox potentials as surrogates for direct measurements of soil TGM flux.

Moore, C. W.; Castro, M. S.

2010-12-01

303

Soil morphology: A key to discovering and understanding the structure and dynamics of soil covers  

International Nuclear Information System (INIS)

Full text: Professor M. Ruellan, Professor Emeritus in Pedology at AgroCampus Rennes, France, visited the SWMCN Subprogramme at IAEA Headquarters on 18 April and presented a seminar on soil morphology, a branch of soil science, studying the forms and arrangement of soil features including soil structures in each soil layer (soil horizon). His presentation reviewed the relationships between soil morphology and physical, chemical and biological processes such as soil biological activities, watershed hydrology and geochemistry, rock weathering, soil formation and erosion, human activities and climatic conditions. The sustainable use of soil resources requires the understanding of soil functions, not only in terms of their physical, chemical and biological properties but also the soil history (i.e. the evolution and functioning of soils), its interaction with nature and its position in the landscape. This understanding is necessary because the spatial diversity of soil structures within a landscape is governed by years of soil evolution and development. (author)

304

Wetting properties of fungi mycelium alter soil infiltration and soil water repellency in a ?-sterilized wettable and repellent soil.  

Science.gov (United States)

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. PMID:23245615

Chau, Henry Wai; Goh, Yit Kheng; Vujanovic, Vladimir; Si, Bing Cheng

2012-12-01

305

Soil management practices for sustainable crop production  

International Nuclear Information System (INIS)

In a sustainable system, the soil is viewed as a fragile and living medium that must be protected and nurtured to ensure its long-term productivity and stability. However, due to high demand for food brought about by high population as well as the decline in agricultural lands, the soil is being exploited beyond its limit thus, leading to poor or sick soils. Sound soil management practices in the Philippines is being reviewed. The technologies, including the advantages and disadvantages are hereby presented. This includes proper cropping systems, fertilizer program, soil erosion control and correcting soil acidity. Sound soil management practices which conserve organic matter for long-term sustainability includes addition of compost, maintaining soil cover, increasing aggregates stability, soil tilt and diversity of soil microbial life. A healthy soil is a key component to sustainability as a health soil produce healthy crop plants and have optimum vigor or less susceptible to pests. (author)

306

Microsoft Word - soil_bidi_CC_functions  

Soil Biodiversity – Effects on Carbon Storage and Water Retention from Climate ...correlations between biodiversity and organic matter in soil and the retention of both water ...is particularly true with the ecosystem of the soil, which many

307

A method to detect soil carbon degradation during soil erosion  

Directory of Open Access Journals (Sweden)

Full Text Available Soil erosion has been discussed intensively but controversial both as a significant source or a significant sink of atmospheric carbon possibly explaining the gap in the global carbon budget. One of the major points of discussion has been whether or not carbon is degraded and mineralized to CO2 during detachment, transport and deposition of soil material. By combining the caesium-137 (137Cs approach (quantification of erosion rates with stable carbon isotope signatures (process indicator of mixing versus degradation of carbon pools we were able to show that degradation of carbon occurs during soil erosion processes at the investigated mountain grasslands in the central Swiss Alps (Urseren Valley, Canton Uri. Transects from upland (erosion source to wetland soils (erosion sinks of sites affected by sheet and land slide erosion were sampled. Analysis of 137Cs yielded an input of 2 and 2.6 t ha?1 yr?1 of soil material into the wetlands sites. Assuming no degradation of soil organic carbon during detachment and transport, carbon isotope signature of soil organic carbon in the wetlands could only be explained with an assumed 800 and 400 years of erosion input into the wetlands. The latter is highly unlikely with alpine peat growth rates indicating that the upper horizons might have an age between 7 and 200 years. While we do not conclude from our data that eroded soil organic carbon is generally degraded during detachment and transport, we propose this method to gain more information on process dynamics during soil erosion from oxic upland to anoxic wetland soils, sediments or water bodies.

C. Alewell

2009-06-01

308

A method to detect soil carbon degradation during soil erosion  

Directory of Open Access Journals (Sweden)

Full Text Available Soil erosion has been discussed intensively but controversial both as a significant source or a significant sink of atmospheric carbon possibly explaining the gap in the global carbon budget. One of the major points of discussion has been whether or not carbon is degraded and mineralized to CO2 during detachment, transport and deposition of soil material. By combining the caesium-137 (137Cs approach (quantification of erosion rates with stable carbon isotope signatures (process indicator of mixing versus degradation of carbon pools we were able to show that degradation of carbon occurs during soil erosion processes at the investigated mountain grasslands in the central Swiss Alps (Urseren Valley, Canton Uri. Transects from upland (erosion source to wetland soils (erosion sinks of sites affected by sheet and land slide erosion were sampled. Analysis of 137Cs yielded an input of 2 and 4.6 tha?1 yr?1 of soil material into the wetlands sites. Assuming no degradation of soil organic carbon during detachment and transport, carbon isotope signature of soil organic carbon in the wetlands could only be explained with an assumed 500–600 and 350–400 years of erosion input into the wetlands Laui and Spissen, respectively. The latter is highly unlikely with alpine peat growth rates indicating that the upper horizons might have an age between 7 and 200 years. While we do not conclude from our data that eroded soil organic carbon is generally degraded during detachment and transport, we propose this method to gain more information on process dynamics during soil erosion from oxic upland to anoxic wetland soils, sediments or water bodies.

F. Conen

2009-11-01

309

Solos urbanos / Urban soils  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese A forte pressão provocada pela expansão urbana desordenada sobre os recursos naturais, principalmente os solos, tem provocado danos, muitas vezes de difícil reparo. A grande concentração populacional em centros urbanos cada vez maiores tem dirigido a atenção de diferentes profissionais para o recurs [...] o solo, no sentido de entender sua dinâmica para minimizar sua degradação. No entanto, a falta de conhecimento sobre as propriedades, bem como sobre a aptidão dos solos sob uso urbano tem provocado o seu mau uso, resultando em processos como compactação, erosão, deslizamentos e inundações, assim como poluição com substâncias orgânicas, inorgânicas e patógenos, aumentando os custos do desenvolvimento afetando toda a sociedade. Neste sentido, este texto discute como o conhecimento pedológico pode diminuir os efeitos negativos provocados pelo processo de urbanização. Abstract in english The strong pressure caused by the disordered urban expansion over the natural resources, mainly the soils, has caused damages, many times difficult to repair. The great population concentration in urban centers getting larger and larger has been driving the attention of different professionals to so [...] il resource, in the sense of understanding its dynamics to minimize its degradation. The lack of knowledge related to the soils properties and capability promote their inappropriate use, resultig in degrading processes as compaction, erosion, sliding, floods, and organic, inorganic and patogenic pollution, increasing the cost of development and affecting the whole society. This text discusses how pedologic knowledge can reduce the negative effects caused by the urbanization process.

Fabrício de Araújo, Pedron; Ricardo Simão Diniz, Dalmolin; Antônio Carlos de, Azevedo; João, Kaminski.

310

Soil Respiration: Concept and Measurement Methods  

Directory of Open Access Journals (Sweden)

Full Text Available Soil respiration is the main element in the carbon cycle that makes possible for plants carbon plants to return inthe atmosphere. The objective of this work was to present and discuss some aspects of the soil CO2 efflux. We definedherein, some terms associated to the soil respiration concept, we tackled some aspects regarding the influence oftemperature, humidity and soil pH on soil respiration and we presented the principle of soil respiration measurement byusing dynamic closed chamber system.

SANDOR M.

2010-08-01

311

Soil decontamination at Rocky Flats  

International Nuclear Information System (INIS)

A soils decontamination project was initiated, to remove actinides from soils at Rocky Flats. Wet screening, attrition scrubbing with Calgon at high pH, attrition scrubbing at low pH, and cationic flotation were investigated. Pilot plant studies were carried out. Conceptual designs have been generated for mounting the process in semi-trailers

312

Soil Investigation on Banks Island.  

Science.gov (United States)

Soils of Banks Island, Northwest Territories, Canada, are predominantly well-drained with many high arctic affinities. Because of the dry desert-like appearance of most of the soils, they are designated collectively as polar desert rather than tundra. Man...

J. C. F. Tedrow, L. A. Douglas

1964-01-01

313

Uptake of radionuclides from soil  

International Nuclear Information System (INIS)

Experiments to determine the transfer factors for the radionuclides 90Sr, 139Cs, 60Co, and 54Mn have been carried out at Juelich research centre since June 1978. A temporary soil contamination caused by an accident (radionuclides entering the 0 to 1 cm soil layer) and a continuous soil contamination (radionuclides entering the 0 to 20 cm topsoil, AP horizon) are simulated. The test plants are agricultural plants such as alfalfa, mixtures of meadow grass, potatoes, sugar beets, winter wheat, spring barley, and clover. If crop rotation on specific soil permits it, also garden cultures such as lettuce, radishes, carrots, and dwarf beans are grown. Preliminary results of the first vegetation period show a wide variation of transfer factors for the radionuclides under investigation in dependence of the type of soil and plant. These variations and the specific dependence of transfer factors on certain soil properties, on the type of plant and its stage of growth at the time of harvesting, on the part of the plant, and on the experimental conditions set a limit to the establishment of a transfer factor to predict the concentration of a radionuclide in a certain plant in a certain soil. Still, it may be possible to give conservative transfer factors for certain types of soil and for the most common crops. (orig.)

314

Approved Practices in Soil Conservation.  

Science.gov (United States)

This book is written for individuals who wish to apply conservation practices, especially those of soil and water conservation, without technical assistance, to meet one's own conditions, and within his own capability to apply them. To meet these needs, the book includes a discussion and description of soil and water conservation methods for the…

Foster, Albert B.

315

FAO's programme on soil erosion  

International Nuclear Information System (INIS)

The present situation of land degradation in global basis and its negative impacts on soil fertility are presented. The activities undertaken by FAO on erosion control are described. Some recent trends in soil and water conservation are also included. (author). 11 refs, 1 fig., 1 tab

316

The impact of soil degradation on soil functioning in Europe  

Science.gov (United States)

The European Commission has presented in September 2006 its Thematic Strategy for Soil Protection.The Thematic Strategy for Soil Protection consists of a Communication from the Commission to the other European Institutions, a proposal for a framework Directive (a European law), and an Impact Assessment. The Communication (COM(2006) 231) sets the frame. It defines the relevant soil functions for Europe and identifies the major threats. It explains why further action is needed to ensure a high level of soil protection, sets the overall objective of the Strategy and explains what kind of measures must be taken. It establishes a ten-year work program for the European Commission. The proposal for a framework Directive (COM(2006) 232) sets out common principles for protecting soils across the EU. Within this common framework, the EU Member States will be in a position to decide how best to protect soil and how use it in a sustainable way on their own territory. The Impact Assessment (SEC (2006) 1165 and SEC(2006) 620) contains an analysis of the economic, social and environmental impacts of the different options that were considered in the preparatory phase of the strategy and of the measures finally retained by the Commission. Since 2006 a large amount of new evidence has allowed to further document the extensive negative impacts of soil degradation on soil functioning in Europe. Extensive soil erosion, combined with a constant loss of soil organic carbon, have raised attention to the important role soils are playing within the climate change related processes. Other important processes are related to the loss of soil biodiversity, extensive soil sealing by housing and infrastructure, local and diffuse contamination by agricultural and industrial sources, compaction due to unsustainable agricultural practices and salinization by unsustainable irrigation practices. The extended impact assessment by the European Commission has attempted to quantify in monetary terms the actual economic impact of soil degradation in Europe.The total costs of soil degradation that could be assessed for erosion, organic matter decline, salinisation, landslides and contamination on the basis of available data, would be up to €38 billion annually for EU25. These estimates are necessarily wide ranging due to the lack of sufficient quantitative and qualitative data. Future research activities will have to address, in multidisciplinary teams, the social and economic aspects of soil degradation in Europe, in order to come up with more reliable estimates of the economic impact of soil degradation. A more reliable and updated system of indicators needs to be developed in order to cover the full cycle of the Driving forces-Pressures-State-Impact-Response (DPSIR) framework. Recent developments towards a new soil monitoring system for Europe will be presented as well as some of the recent outputs of the European Soil Data Centre (ESDAC).

Montanarella, Luca

2010-05-01

317

Shrinkage limit of soil mixtures  

International Nuclear Information System (INIS)

Shrinkage limit, one of the Atterberg limits, is widely linked with many plasticity-based soil behaviors. However, in a great majority of these cases, such correlations have been found to exhibit poor performance. Recently, it has been brought out that the shrinkage limit of a natural soil does not depend upon plasticity characteristics, and it is primarily governed by the relative grain size distribution of the soil. The present study confirms this mechanism with the results obtained using clay-clay, clay-non-cohesive soil, and non-cohesive soil mix systems. The present study gains importance from the point of view of criteria with respect to the design of back fill materials to be used in various applications, such as nuclear waste disposal projects

318

Soil Erosion Threatens Food Production  

Directory of Open Access Journals (Sweden)

Full Text Available Since humans worldwide obtain more than 99.7% of their food (calories from the land and less than 0.3% from the oceans and aquatic ecosystems, preserving cropland and maintaining soil fertility should be of the highest importance to human welfare. Soil erosion is one of the most serious threats facing world food production. Each year about 10 million ha of cropland are lost due to soil erosion, thus reducing the cropland available for world food production. The loss of cropland is a serious problem because the World Health Organization and the Food and Agricultural Organization report that two-thirds of the world population is malnourished. Overall, soil is being lost from agricultural areas 10 to 40 times faster than the rate of soil formation imperiling humanity’s food security.

Michael Burgess

2013-08-01

319

Phytoremediation for Oily Desert Soils  

Science.gov (United States)

This chapter deals with strategies for cleaning oily desert soils through rhizosphere technology. Bioremediation involves two major approaches; seeding with suitable microorganisms and fertilization with microbial growth enhancing materials. Raising suitable crops in oil-polluted desert soils fulfills both objectives. The rhizosphere of many legume and non-legume plants is richer in oil-utilizing micro-organisms than non-vegetated soils. Furthermore, these rhizospheres also harbour symbiotic and asymbiotic nitrogen-fixing bacteria, and are rich in simple organic compounds exuded by plant roots. Those exudates are excellent nutrients for oil-utilizing microorganisms. Since many rhizospheric bacteria have the combined activities of hydrocarbon-utilization and nitrogen fixation, phytoremediation provides a feasible and environmentally friendly biotechnology for cleaning oil-polluted soils, especially nitrogen-poor desert soils.

Radwan, Samir

320

Evaluation of soil washing for radiologically contaminated soils  

International Nuclear Information System (INIS)

Soil washing has been applied internationally to decontaminate soils due to the widespread increase in environmental awareness manifested in the United States by promulgation of the Comprehensive Environmental Response, Compensation and Liability Act, yet we continue to lack understanding on why the technique works in one application and not in another. A soil washing process typically integrates a variety of modules, each designed to decontaminate the matrix by destroying a particular phase or segregating a particle size fraction in which the contaminants are concentrated. The more known about how the contaminants are fixed, the more likely the process will succeed. Much can be learned from bioavailability studies on heavy metals in soils. Sequential extraction experiments designed to destroy one fixation mechanism at a time can be used to determine how contaminants are bound. This knowledge provides a technical basis for designing a processing strategy to efficiently decontaminate soil while creating a minimum of secondary wastes. In this study, a soil from the Idaho National Engineering Laboratory was physically and chemically characterized, then sequentially extracted to determine if soil washing could be effectively used to remove cesium, cobalt and chromium

 
 
 
 
321

Evaluation of soil washing for radiologically contaminated soils  

Energy Technology Data Exchange (ETDEWEB)

Soil washing has been applied internationally to decontaminate soils due to the widespread increase in environmental awareness manifested in the United States by promulgation of the Comprehensive Environmental Response, Compensation and Liability Act, yet we continue to lack understanding on why the technique works in one application and not in another. A soil washing process typically integrates a variety of modules, each designed to decontaminate the matrix by destroying a particular phase or segregating a particle size fraction in which the contaminants are concentrated. The more known about how the contaminants are fixed, the more likely the process will succeed. Much can be learned from bioavailability studies on heavy metals in soils. Sequential extraction experiments designed to destroy one fixation mechanism at a time can be used to determine how contaminants are bound. This knowledge provides a technical basis for designing a processing strategy to efficiently decontaminate soil while creating a minimum of secondary wastes. In this study, a soil from the Idaho National Engineering Laboratory was physically and chemically characterized, then sequentially extracted to determine if soil washing could be effectively used to remove cesium, cobalt and chromium.

Gombert, D. II

1994-03-01

322

know Soil Know Life - Getting Kids Excited About Soils  

Science.gov (United States)

In the United States soils are often taught in primary school (grade 3-6) but with little excitement or passion. We have been working with schools and teachers to bring our passion about soils to this audience. The methods and message can be conveyed simply and effectively by engaging the students in a dialog and through kinematic learning. Our approach is to begin with a simple question - what are 4 things we cannot live without. The answer - Air, Water, Sunlight, and Soil. Most students say "food, shelter, clothing, plants, animals etc." so we then explain all of those come from soil. This leads us to a quick "dance" illustrating that without soils we would be 'Hungry. Homeless, and Naked". The results are that students and teachers remember this simple message. From this point it is our hope that students will continue to understand the importance of soils and stop treating soils like dirt. Other simple exercises for this younger audience will also be presented.

Lindbo, David L.; Robinson, Clay; Kozlowski, Deborah

2014-05-01

323

Soil characteristics driving arbuscular mycorrhizal fungi communities in semiarid soils  

Science.gov (United States)

Arbuscular mycorrhizal fungi (AMF) are an important soil microbial group that affects multiple ecosystems functions and processes, including nutrient cycling, plant productivity and competition, and plant diversity. We carried out a study to investigate AMF communities in the roots and the rhizosphere of Brachypodium retusum (Pers.) Beauv., a common plant species of great ecological importance that grows in different type of soils in semiarid Mediterranean areas with similar climatic conditions. We hypothesized that if both factors, host plant species and climatic conditions, cannot influence the differences in AMF communities in the roots and in the rhizosphere of Brachypodium retusum, variances in AMF richness and diversity could be due to soil characteristics. Hence we study the relationships between physical, chemical and biological soil characteristics and AMF community composition found in the roots and in the rhizospheres. We recorded sixty-seven AMF operational taxonomical units (OTUs). Each soil type presented a different AMF community composition and thus, can be characterized by its own AMF communities. A combination among some of the soil parameters could define the AMF species present in the roots and the rhizosphere of B. retusum. It was the case for calcium, urease, protease and ß-glucosidase which explained the variation in the AMF communities. In conclusion, soil charactristics can be decisive in the assembling of the AMF communities, managing the diversity and composition of these communities.

Torrecillas, Emma; del Mar Alguacil, Maria; Torres, Pilar; Díaz, Gisela; Caravaca, Fuensanta; Montesinos, Alicia; Roldán, Antonio

2014-05-01

324

How Soil Organic Matter Composition Controls Hexachlorobenzene-Soil-Interactions: Adsorption Isotherms and Quantum Chemical Modelling  

CERN Document Server

Hazardous persistent organic pollutants (POPs) interact in soil with the soil organic matter (SOM) but this interaction is insufficiently understood at the molecular level. We investigated the adsorption of hexachlorobenzene (HCB) on soil samples with systematically modified SOM. These samples included the original soil, the soil modified by adding a hot water extract (HWE) fraction (soil+3 HWE and soil+6 HWE), and the pyrolyzed soil. The SOM contents increased in the order pyrolyzed soil < original soil < soil+3 HWE < soil+6 HWE. For the latter three samples this order was also valid for the HCB adsorption. The pyrolyzed soil adsorbed more HCB than the other samples at low initial concentrations, but at higher concentrations the HCB adsorption became weaker than in the samples with HWE addition. This adsorption behaviour combined with the differences in the chemical composition between the soil samples suggested that alkylated aromatic, phenol, and lignin monomer compounds contributed most to the HC...

Ahmed, Ashour; Kühn, Oliver

2013-01-01

325

A Review of Fishpond Soil Management Principles in Nigeria  

Directory of Open Access Journals (Sweden)

Full Text Available The suitability of sites for culture fisheries depends on the soil. There is therefore the need to have proper background on the nature and properties of soils. The pond oils, soil functions in fish pond, soil characterization, components and soil mineral constituents, oil profile soil classification, soil fertility, nutrients, primary and secondary nutrients, soil organic matter, common soil problems, field and laboratory methods in acid sulphate soil identification, management of acid sulphate soil conditions, lime requirements for soils, alkalinity/sodicity, salinity, excess organic matter, soil sampling and analysis are reviewed in this article to provide the needed background in soil for effective culture fisheries management and practices.

A.T. Ekubo

2011-11-01

326

Soil mesofauna of taiga burozems  

Science.gov (United States)

In the burozems of the plains, the composition of the invertebrates and saprophages (the prevailing primary destroyers) differed from that in the mountainous soils only by the absence of millipedes of the Geophilomorpha order. At the same time, the differences in these characteristics between the burozems and soddypodzolic soils of the neighboring coniferous-broad-leaved forests were more significant: in the latter, the composition of the ecological groups of earthworms was more diverse. Among the earthworms, secondary destroyers (detritophages) consuming well-decomposed residues of plants and animals predominated: Aporrectodea caliginosa, A. rosea, and Octolasium lacteum. In the taiga burozems, among the secondary destroyers, very few O. lacteum among the earthworms, and Polyzonium germanicum among the millipede diplopods were found. Primary destroyers that only comminute plant tissues ( Dendrobaena octaedra and Dendrodrilus rubidus f. tenuis) were the main representatives in the invertebrate population of these soils. The differences also concerned the group composition and the proportion between the life forms of the earthworms. In the southern taiga burozems, only the litter ( Dendrobaena octaedra and Dendrodrilus rubidus f. tenuis) earthworms and species of the upper soil layer ( Octolasium lacteum) were present. In the mountainous burozems of the Transcarpathian region, litter inhabitants ( Dendrobaena attemsi and Aporrectodea submontana), soil-litter inhabitants ( Dendrobaena alpina—Transcarpathian region), and inhabitants of the upper ( Helodrilus cernosvitovianus) and middle ( Aporrectodea carpathica and A. sturanyi) soil layers (in the Primorskii region, only the soil-litter Eisenia nordenskioldi) were identified. In the soddy-podzolic soils, dwellers of the middle soil layers ( Aporrectodea caliginosa, A. rosea, and Lumbricus terrestris) were constantly present along with the species dwelling in the litter and in the upper soil layers (in the litter— Dendrobaena octaedra, Dendrodrilus rubidus f. tenuis, and L. castaneus; in the litter-soil layer— L. rubellus; in the upper soil layer— Octolasium lacteum). The higher diversity of the earthworm life forms in the soddy-podzolic soils points to the stronger development of their humus horizons as compared to those horizons in the burozems of the southern taiga and mountains.

Gryuntal', S. Yu.

2009-11-01

327

Root Patterns in Heterogeneous Soils  

Science.gov (United States)

Heterogeneous water availability is a typical characteristic of soils in which plant roots grow. Despite the intrinsic heterogeneity of soil-plant water relations, we know little about the ways how plants respond to local environmental quality. Furthermore, increasing use of soil amendments as partial water reservoirs in agriculture calls for a better understanding of plant response to soil heterogeneity. Neutron radiography is a non-invasive imaging that is highly sensitive to water and root distribution and that has high capability for monitoring spatial and temporal soil-plant water relations in heterogeneous systems. Maize plants were grown in 25 x 30 x 1 cm aluminum slabs filled with sandy soil. On the right side of the compartments a commercial water absorbent (Geohumus) was mixed with the soil. Geohumus was distributed with two patterns: mixed homogeneously with the soil, and arranged as 1-cm diameter aggregates (Fig. 1). Two irrigation treatments were applied: sufficient water irrigation and moderate water stress. Neutron radiography started 10 days after planting and has been performed twice a day for one week. At the end of the experiment, the containers were opened, the root were removed and dry root weight in different soil segments were measured. Neutron radiography showed root growth tendency towards Geohumus treated parts and preferential water uptake from Geohumus aggregates. Number and length of fine lateral roots were lower in treated areas compared to the non-treated zone and to control soil. Although corn plants showed an overall high proliferation towards the soil water sources, they decreased production of branches and fine root when water was more available near the main root parts. However there was 50% higher C allocation in roots grown in Geohumus compartments, as derived by the relative dry weight of root. The preferential C allocation in treated regions was higher when plants grew under water stress. We conclude that in addition to the inherent effect of water absorbent materials on increasing soil water availability, the distribution pattern of the soil amendments had an important role on root growth strategy and plant water uptake. Neutron radiography of the top, right corner of one sample. The Geohumus is arranged as aggregates.

Dara, A.; Moradi, A. B.; Carminati, A.; Oswald, S. E.

2010-12-01

328

The use of isotopes in soil fertility and soil chemistry  

International Nuclear Information System (INIS)

The concept of radioactive and enriched stable isotopes is reminded. The main topics studied with isotopes which are pointed out are the following: the isotopic exchange and its application; the E and L values; the determination of CEC; the fixing capacity of some ions by the soil particles; the measurement of the A value; the efficiency of fertilizers utilization, the interaction between nutrients, their movements through the soil, the residual effect of the fertilizers and, finally, the root system and soil organic matter. (author)

329

Soil Vapor Extraction of PCE/TCE Contaminated Soil  

International Nuclear Information System (INIS)

The A/M Area of the Savannah River Site soil and groundwater is contaminated with tetrachloroethylene (PCE) and trichloroethylene (TCE). Contamination is the result of previous waste disposal practices, once considered state-of-the-art. Soil Vapor Extraction (SVE) units have been installed to remediate the A/M Area vadose zone. SVE is a proven in-situ method for removing volatile organics from a soil matrix with minimal site disturbance. SVE alleviates the infiltration of contaminants into the groundwater and reduces the total time required for groundwater remediation. Lessons learned and optimization of the SVE units are also discussed

330

Reactivity of iodide in volcanic soils and noncrystalline soil constituents  

Science.gov (United States)

Reaction of iodide [I-(aq)] with a series of volcanic-ash soils was compared with reaction onto noncrystalline materials that constitute much of the inorganic fraction of these soils, Our hypothesis is that these high-surface-area materials account for iodide retention by providing sites for anion exchange. Iodide sorption onto imogolite and ferrihydrite is rapid (iodine. Solutions of molecular iodine [I2(aq)] react relatively quickly with laboratory-grade humic acid solutions and the rate increases with increasing pH. The slow rate of iodination is consistent with the continual formation and reaction of I2(aq)] or HOI(aq) by titration with soil organic matter.

Yu, Zengshou; Warner, Jeffrey A.; Dahlgren, Randy A.; Casey, William H.

1996-12-01

331

Soil decontamination with Extraksol  

International Nuclear Information System (INIS)

The Extraksol process is a mobile decontamination technology which treats unconsolidated materials by solvent extraction. Treatment with Extraksol involves material washing, drying and solvent regeneration. Contaminant removal is achieved through desorption/dissolution mechanisms. The treated material is dry and acceptable to be reinstalled in its original location. The process provides a fast, efficient and versatile alternative for decontamination of soil and sludge. The organic contaminants extracted from the matrix are transferred to the extraction fluids. These are thereafter concentrated in the residues of distillation after solvent regeneration. Removal and concentration of the contaminants ensures an important waste volume reduction. This paper presents the process is operational principles and the steps involved in Extraksol's development with results of the pilot tests and full-scale demonstrations

332

Spatial variation of soil physical properties in adjacent alluvial and colluvial soils under Ustic moisture regime  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Soils vary spatially due to differences in soil management and soil formation factors. The soil spatial variability is an important determinant of efficiency of farm inputs and yield. This study was carried out to identify and compare spatial variation of some soil physical properties by geostatistics in alluvial and adjacent colluvial soils formed under ustic moisture regime at Gökhöyük State Farm (1750 ha), Amasya, Turkey. Seventy four soil samples were collected on a regular grid (500 ?...

Sag?lam, M.; O?ztu?rk, H. S.; Ers?ahin, S.; I? O?zkan, A.

2011-01-01

333

Effect of Soil Amendments on Hydraulic Characteristics of Two Types of Soil  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A laboratory experiment conducted to evaluate the action of some soil amendments on improving physical properties of two soil textures, Clay Loam and Sandy Clay Loam soils. Three soil amendments, with two doses each were applied. Aggregate stability and hydraulic conductivity values were found higher with Sandy Clay Loam soil (SCL) than Clay Loam soil (CL). For both soils all treatments gave significantly higher aggregate stability index than control treatment. For a given amendment used Wet ...

Al-samarrai, M. A.; Al-lami, M. M.; Abdul-majeed, H.

2005-01-01

334

Direct soil moisture controls of future global soil carbon changes: An important source of uncertainty  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The nature of the climate–carbon cycle feedback depends critically on the response of soil carbon to climate, including changes in moisture. However, soil moisture–carbon feedback responses have not been investigated thoroughly. Uncertainty in the response of soil carbon to soil moisture changes could arise from uncertainty in the relationship between soil moisture and heterotrophic respiration. We used twelve soil moisture–respiration functions (SMRFs) with a soil carbon model (RothC) ...

Fallon, Pete; Jones, Chris D.; Ades, Melanie; Paul, Keryn

2011-01-01

335

Tracing soil erosion impacts on soil organisms using 137Cs and soil nematodes  

Science.gov (United States)

The application of environmental radionuclides in soil tracing and erosion studies is now well established in geomorphology. Sediment and erosion-tracing studies are undertaken for a range of purposes in the earth sciences but until now few studies have used the technique to answer biological questions. An experiment was undertaken to measure patterns of soil loss and gain over 50 years, effectively calculating a field-scale sediment budget, to investigate soil erosion relationships between physical and biological soil components. Soil nematodes were identified as a model organism, a ubiquitous and abundant group sensitive to disturbance and thus useful indicator taxa of biological and physico-chemical changes. A field site was selected at the James Hutton Institute's experimental Balruddery Farm in NE Scotland. 10 metre-resolution topographical data was collected with differential GPS. Based on these data, a regular 30 m-resolution sampling grid was constructed in ArcGIS, and a field-sampling campaign undertaken. 104 soil cores (~50 cm-deep) were collected with a percussion corer. Radio-caesium (137Cs) activity concentrations were measured using high-purity germainum gamma-ray spectroscopy, and 137Cs areal activities derived from these values. Organic matter content by loss on ignition and grain-size distribution by laser granulometry were also measured. Additional samples were collected to characterise the soil nematode community, both for abundance and functional (trophic) composition using a combination of low-powered microscopy and molecular identification techniques (dTRFLP). Results were analysed with ArcGIS software using the Spatial Analyst package. Results show that spatial relationships between physical, chemical and biological parameters were complex and interrelated. Previous field management was found to influence these relationships. The results of this experiment highlight the role that soil erosion processes play in medium-term restructuring of the physico-chemical soil environment and the soil community.

Baxter, Craig; Rowan, John S.; McKenzie, Blair M.; Neilson, Roy

2014-05-01

336

Afforestation effects on soil carbon  

DEFF Research Database (Denmark)

Understanding carbon (C) dynamics has become increasingly important due to the major role of C in global warming. Soils store the largest amount of organic C in the biosphere; therefore, changes in this compartment can have a large impact on the C storage of an ecosystem. Land-use change is a main driver of changes in soil organic carbon (SOC) pools worldwide. In Europe, afforestation (i.e. the establishment of new forest on non-forested land), is a major land-use change driven by economic and environmental interests due to its role as a C sequestration tool following the ratification of the Kyoto Protocol. Despite research efforts on the quantification of SOC stock change and soil C fluxes following this land-use change, knowledge is still scarce in regions where afforestation currently is and has been widespread, like Denmark and the rest of Northern Europe. This PhD thesis explored three main aspects of the impact of afforestation on soil C: i) changes in SOC stocks (in forest floors and mineral soils) on afforested cropland in Denmark and in afforested soils of Northern Europe; ii) changes in CH4 oxidation (uptake) potential of soils; iii) changes in soil CO2 efflux through heterotrophic respiration. In Denmark chronosequences (i.e. space-for-time substitution) of oak and Norway spruce stands at the Vestskoven site were the tool used to explore these changes. Soil OC dynamics predicted by the chronosequence approach have often been used, however they never been validated by resampling before. According to the chronosequence approach covering a time span of 40 years, topsoils (0-25 cm soil depth including forest floors) in Vestskoven are currently neither a sink nor a source for C. The more specific decadal trends at the stand level provided by repeated sampling revealed a change in source-sink C balance between soil compartments over time, with C accumulation in the mineral soil becoming increasingly important as the sink strength of forest floors decreased within 4 decades of afforestation. The chronosequence approach is an appropriate tool to assess SOC stock changes following afforestation given that assumptions of similar site conditions are met. However, repeated sampling can not only validate the chronosequence trajectories but also provide refined temporal trends. Changes in SOC in Northern Europe investigated by meta-analysis, revealed that following afforestation, significant C sequestration in soils from this region requires at least three decades or even longer time, when afforestation is performed on former agricultural soils. The faster C accretion in forest floors compensates the initial lag-phase found in mineral soils. The chronosequences also indicated that afforestation increases the CH4 sink potential of soils over time due to the gradual increase in SOC and decrease of bulk density favoring CH4-oxidation, as long as soils remain well drained. The CO2 efflux from soils may increase, due to heterotrophic respiration of a larger SOC pool and not due to higher reactivity of the SOC. However, these C sources are likely to be compensated by the C sink in the growing forest biomass.

Bárcena, Teresa G

2013-01-01

337

Soil CO? dynamics in a tree island soil of the Pantanal: the role of soil water potential.  

Science.gov (United States)

The Pantanal is a biodiversity hotspot comprised of a mosaic of landforms that differ in vegetative assemblages and flooding dynamics. Tree islands provide refuge for terrestrial fauna during the flooding period and are particularly important to the regional ecosystem structure. Little soil CO? research has been conducted in this region. We evaluated soil CO? dynamics in relation to primary controlling environmental parameters (soil temperature and soil water). Soil respiration was computed using the gradient method using in situ infrared gas analyzers to directly measure CO? concentration within the soil profile. Due to the cost of the sensors and associated equipment, this study was unreplicated. Rather, we focus on the temporal relationships between soil CO? efflux and related environmental parameters. Soil CO? efflux during the study averaged 3.53 µmol CO? m?² s?¹, and was equivalent to an annual soil respiration of 1220 g C m?² y?¹. This efflux value, integrated over a year, is comparable to soil C stocks for 0-20 cm. Soil water potential was the measured parameter most strongly associated with soil CO? concentrations, with high CO? values observed only once soil water potential at the 10 cm depth approached zero. This relationship was exhibited across a spectrum of timescales and was found to be significant at a daily timescale across all seasons using conditional nonparametric spectral Granger causality analysis. Hydrology plays a significant role in controlling CO? efflux from the tree island soil, with soil CO? dynamics differing by wetting mechanism. During the wet-up period, direct precipitation infiltrates soil from above and results in pulses of CO? efflux from soil. The annual flood arrives later, and saturates soil from below. While CO? concentrations in soil grew very high under both wetting mechanisms, the change in soil CO? efflux was only significant when soils were wet from above. PMID:23762259

Johnson, Mark S; Couto, Eduardo Guimarães; Pinto, Osvaldo B; Milesi, Juliana; Santos Amorim, Ricardo S; Messias, Indira A M; Biudes, Marcelo Sacardi

2013-01-01

338

Sustaining "the Genius of Soils"  

Science.gov (United States)

Soils are weathered porous earth surficial materials that exhibit an approximately vertical stratification reflecting the continual action of percolating water and living organisms. They are complex open, multicomponent, multiphase biogeochemical systems which function as both provisioning and regulatory agents in terrestrial ecosystems while influencing aquatic ecosystems through their impacts on evapotranspiration and runoff. The ability of soils to engage in their supportive ecosystem functions depends on what has been termed metaphorically as their "natural capital," the defining properties that condition soil response to biological, geological, and hydrological processes as well as human-driven activities. Natural capital must necessarily differ among soils depending on how they have developed under the five soil-forming processes, but it also can be determined by land use and by the flows of matter and energy that link the global atmosphere, biosphere, and hydrosphere. These latter two determinants have in recent decades begun to exhibit strong variability that exceeds what has been characteristic of them during the past 10 millennia of earth history, thereby raising the apocalyptic issue of whether a deleterious or even catastrophic undermining of the ability of soils to function supportively in ecosystems is in the offing. Resolving this issue will require deeper understanding of how soils perform their provisioning and regulatory functions, how they respond to land-use changes, and how they mediate the global flows of matter and energy.

Sposito, G.

2011-12-01

339

Mycelial bacteria of saline soils  

Science.gov (United States)

The actinomycetal complexes of saline soils comprise the representatives of the Streptomyces and Micromonospora genera, the number of which are hundreds and thousands of CFU/g soil. Complexes of mycelial bacteria in saline soils are poorer in terms of number (by 1-3 orders of magnitude) and taxonomic composition than the complexes of the zonal soil types. A specific feature of the actinomycetal complexes of saline soils is the predominance of halophilic, alkaliphilic, and haloalkaliphilic streptomycetes that well grow at pH 8-9 and concentrations of NaCl close to 5%. Actinomycetes in saline soils grow actively, and the length of their mycelium reaches 140 m in 1 gram of soil. The haloalkaliphilic streptomycetes grow fast and inhibit the formation of spores at pH 9 and high concentrations of salts (Na2SO4 and MgCl2, 5%) as compared to their behavior on a neutral medium with a salt concentration of 0.02%. They are characterized by the maximal radial growth rate of colonies on an alkaline medium with 5% NaCl.

Zvyagintsev, D. G.; Zenova, G. M.; Oborotov, G. V.

2008-10-01

340

The soil reference shrinkage curve  

CERN Document Server

A recently proposed model showed how a clay shrinkage curve is transformed to the soil shrinkage curve at the soil clay content higher than a critical one. The objective of the present work was to generalize this model to the soil clay content lower a critical one. I investigated (i) the reference shrinkage curve, that is, one without cracks; (ii) the superficial layer of aggregates, with changed pore structure compared with the intraaggregate matrix; and (iii) soils with sufficiently low clay content where there are large pores inside the intraaggregate clay (so-called lacunar pores). The methodology is based on detail accounting for different contributions to the soil volume and water content during shrinkage. The key point is the calculation of the lacunar pore volume variance at shrinkage. The reference shrinkage curve is determined by eight physical soil parameters: (1) oven-dried specific volume; (2) maximum swelling water content; (3) mean solid density; (4) soil clay content; (5) oven-dried structural...

Chertkov, V Y

2014-01-01

 
 
 
 
341

A Review of Fishpond Soil Management Principles in Nigeria  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The suitability of sites for culture fisheries depends on the soil. There is therefore the need to have proper background on the nature and properties of soils. The pond oils, soil functions in fish pond, soil characterization, components and soil mineral constituents, oil profile soil classification, soil fertility, nutrients, primary and secondary nutrients, soil organic matter, common soil problems, field and laboratory methods in acid sulphate soil identification, management of acid sulph...

Ekubo, A. T.; Abowei, J. F. N.

2011-01-01

342

The Kinematics of Soil Water  

International Nuclear Information System (INIS)

Relatively simple physical-mathematical models have been quite successful in describing the flow of water in saturated and in partially saturated soils. The main features in these models are, (1) a balance of mass for the water, (2) a dynamical statement relating the velocity of the water relative to the solid phase, to the forces causing the movement of the water, and (3) a capacity relation, e.g., for a partially saturated soil the relationship between the water content and the pressure head. These models treat the soil water in a macroscopic sense as a continuous medium. Kinematics deal with concepts that are useful in characterizing the motion of a continuous medium. Regarding the soil water as a continuous medium leads naturally to a discussion of the kinematics of soil water. Among the kinematic concepts considered are: velocity, vorticity, stream line, path line, streak line, and collections of particles forming a surface. The main purpose is to describe the restrictions imposed upon the kinematics of the soil-water movement by conservation of mass, the dynamical law, and the capacity relation. Several special cases are discussed. The soil may be saturated; the solid phase may be homogeneous or not homogeneous; and the flow of the water may be steady or unsteady. The nature of the velocity field of the water in the various cases is discussed. The relationship between the kinematics of the motion and surfaces of equal total potential, of equal pressure potential, and, in the case of a partially saturated soil, of equal water content, is described. Radioactive tracers are very useful in studying the kinematics of soil water. The aims and limitations of several tracer techniques will be interpreted in terms of kinematic concepts. (author)

343

Soil carbon determination by thermogravimetrics  

Directory of Open Access Journals (Sweden)

Full Text Available Determination of soil constituents and structure has a vital role in agriculture generally. Methods for the determination of soil carbon have in particular gained greater currency in recent times because of the potential that soils offer in providing offsets for greenhouse gas (CO2-equivalent emissions. Ideally, soil carbon which can also be quite diverse in its makeup and origin, should be measureable by readily accessible, affordable and reliable means. Loss-on-ignition is still a widely used method being suitably simple and available but may have limitations for soil C monitoring. How can these limitations be better defined and understood where such a method is required to detect relatively small changes during soil-C building? Thermogravimetric (TGA instrumentation to measure carbonaceous components has become more interesting because of its potential to separate carbon and other components using very precise and variable heating programs. TGA related studies were undertaken to assist our understanding in the quantification of soil carbon when using methods such as loss-on-ignition. Combining instrumentation so that mass changes can be monitored by mass spectrometer ion currents has elucidated otherwise hidden features of thermal methods enabling the interpretation and evaluation of mass-loss patterns. Soil thermogravimetric work has indicated that loss-on-ignition methods are best constrained to temperatures from 200 to 430 °C for reliable determination for soil organic carbon especially where clay content is higher. In the absence of C-specific detection where mass only changes are relied upon, exceeding this temperature incurs increasing contributions from inorganic sources adding to mass losses with diminishing contributions related to organic matter. The smaller amounts of probably more recalcitrant organic matter released at the higher temperatures may represent mineral associated material and/or simply more refractory forms.

Robert Pallasser

2013-02-01

344

Hillslope Soils and Life (Invited)  

Science.gov (United States)

That hillslope processes are impacted by biology has been long understood, but the complexities of the abiotic-biotic processes and their feedbacks are quantitatively emerging with the growing body of pertinent literature. The concept that plants modulate both the disaggregation and transport of soil particles on hillslopes was clearly articulated by G.K. Gilbert. Yet earlier, James Hutton (starting from very different intellectual boundary conditions) argued that soil, which results from the dynamic balance of rock destruction and removal, is a prerequisite for plants - a concept that underscores the need to more deeply examine the feedback of geomorphic processes on terrestrial ecosystems. We compiled the results of recent studies that have been conducted on gentle convex hillslopes across a broad range of rainfall. We found that vegetated landscapes appear to have strong controls on hillslope soil thickness, landscape denudation rates, and soil residence times. The restricted range in residence times - despite large differences in climate - appear in turn to sustain relatively high levels of both nitrogen (N) and phosphorus (P) fertility, suggesting ecological resilience and resistance to non-anthropogenic environmental perturbations. At the most arid end of Earth's climate vegetation disappears, but not all water. The loss of plants shifts soil erosion to abiotic processes, with a corresponding thinning or loss of the soil mantle. This reinforces the hypothesis that a planet without vegetation, but with a hydrologic cycle, would be largely devoid of soil-mantled hillslopes and would be driven toward hillslope morphologies that differ from the familiar convex-up forms of biotic landscapes. While our synthesis of the effects of vegetation on soil production and soil thickness provides a quantitative view of the suggestions of Gilbert, it also identifies that vegetation itself responds to the geomorphic processes, as believed by Hutton. There is a complex interplay between physical and biological processes on the Earth's surface that requires further elucidation in order to fully understand the ramifications of further climatic and physical alteration of our planet's surface.

Amundson, R.; Owen, J. J.; Heimsath, A. M.; Yoo, K.; Dietrich, W. E.

2013-12-01

345

Improvement of anaerobic soil disinfestation.  

Science.gov (United States)

With increasing worldwide restrictions for soil fumigants, growers loose an important tool to control soilborne pests and pathogens. Environmentally friendly alternatives are urgently needed and anaerobic soil disinfestation (ASD) may be one of them. Traditional ASD with fresh grass is already applied in open field vegetables but the mode of action is unknown. Therefore, trials were performed under controlled conditions using soil-filled buckets, in which several processed defined organic materials were incorporated and compared with fresh grass. The effect of inundation was also studied. Target organisms were Pratylenchus penetrans, Meloidogyne hapla, Globodera pallida and Verticillium dahliae. Results showed that grass (traditional ASD) was less effective than the organic materials. All materials proved to be effective at 16 degrees C against all target organisms. However, exposure time, dosages, soil type and the temperature at which the experiments were performed influenced the effectiveness. P. penetrans was eliminated most easily whereas V. dahliae was most difficult to control. Efficacy was higher in sandy soil than in light marine clay. Inundation at 16 degrees C proved to be effective against P. penetrans and G. pallida in both soil types at sufficient exposure times. A soil temperature of 8 degrees C was sometimes too low for efficacy. Gas production of CO2, NH3, H2S, CH4 and N2O and gas consumption of O2 and production of fatty acids during ASD proved to depend on type of organic materials, soil type, temperature, dosage and exposure time. This first step in unravelling the mode of action has already shown several critical parameters for efficacy. Additional knowledge about the complete mechanisms of action may lead to a more reliable, effective and quicker soil disinfestation. PMID:23885444

Runia, W T; Molendirk, L P G; Ludeking, D J W; Schomaker, C H

2012-01-01

346

Soils - Part 1: The Origin and Development of Soil(How Soil Gets a Life and a Name)  

Science.gov (United States)

In this lesson, you will gain an understanding of the five soil forming factors and will be able to describe how each influences soil development. You will learn to identify common parent materials, determine the age of a soil, identify the types of native vegetation associated with different soils in Nebraska and define soil horizons.[This lesson, as well as the other nine lessons in the Soils series, is taken from the "Soils Home Study Course," published in 1999 by the University of Nebraska Cooperative Extension.

347

Uranium soils integrated demonstration: Soil characterization project report  

Energy Technology Data Exchange (ETDEWEB)

An Integrated Demonstration Program, hosted by the Fernald Environmental Management Project (FEMP), has been established for investigating technologies applicable to the characterization and remediation of soils contaminated with uranium. Critical to the design of relevant treatment technologies is detailed information on the chemical and physical characteristics of the uranium waste-form. To address this need a soil sampling and characterization program was initiated which makes use of a variety of standard analytical techniques coupled with state-of-the-art microscopy and spectroscopy techniques. Sample representativeness is evaluated through the development of conceptual models in an effort to identify and understand those geochemical processes governing the behavior of uranium in FEMP soils. Many of the initial results have significant implications for the design of soil treatment technologies for application at the FEMP.

Cunnane, J.C. [Argonne National Lab., IL (United States); Gill, V.R. [Fernald Environmental Restoration Management Corp., Cincinnati, OH (United States); Lee, S.Y. [Oak Ridge National Lab., TN (United States); Morris, D.E. [Los Alamos National Lab., NM (United States); Nickelson, M.D. [HAZWRAP, Oak Ridge, TN (United States); Perry, D.L. [Lawrence Berkeley Lab., CA (United States); Tidwell, V.C. [Sandia National Labs., Albuquerque, NM (United States)

1993-08-01

348

Uranium soils integrated demonstration: Soil characterization project report  

International Nuclear Information System (INIS)

An Integrated Demonstration Program, hosted by the Fernald Environmental Management Project (FEMP), has been established for investigating technologies applicable to the characterization and remediation of soils contaminated with uranium. Critical to the design of relevant treatment technologies is detailed information on the chemical and physical characteristics of the uranium waste-form. To address this need a soil sampling and characterization program was initiated which makes use of a variety of standard analytical techniques coupled with state-of-the-art microscopy and spectroscopy techniques. Sample representativeness is evaluated through the development of conceptual models in an effort to identify and understand those geochemical processes governing the behavior of uranium in FEMP soils. Many of the initial results have significant implications for the design of soil treatment technologies for application at the FEMP

349

Methods of soil organic carbon determination in Brazilian savannah soils  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english Several methods exist for determining soil organic carbon, and each one has its own advantages and limitations. Consequently, a comparison of the experimental results obtained when these methods are employed is hampered, causing problems in the comparison of carbon stocks in soils. This study aimed [...] at evaluating the analytical procedures used in the determination of carbon and their relationships with soil mineralogy and texture. Wet combustion methods, including Walkley-Black, Mebius and Colorimetric determination as well as dry combustion methods, such as Elemental and Gravimetric Analysis were used. Quantitative textural and mineralogical (kaolinite, goethite and gibbsite) analyses were also carried out. The wet digestion methods underestimated the concentration of organic carbon, while the gravimetric method overestimated. Soil mineralogy interfered with the determination of carbon, with emphasis on the gravimetric method that was greatly influenced by gibbsite.

Juliana Hiromi, Sato; Cícero Célio de, Figueiredo; Robélio Leandro, Marchão; Beáta Emöke, Madari; Luiz Eduardo Celino, Benedito; Jader Galba, Busato; Diego Mendes de, Souza.

2014-08-01

350

Soil Data Analysis Using Classification Techniques and Soil Attribute Prediction  

Directory of Open Access Journals (Sweden)

Full Text Available Agricultural research has been profited by technical advances such as automation, data mining. Today ,data mining is used in a vast areas and many off-the-shelf data mining system products and domain specific data mining application soft wares are available, but data mining in agricultural soil datasets is a relatively a young research field. The large amounts of data that are nowadays virtually harvested along with the crops have to be analyzed and should be used to their full extent. This research aims at analysis of soil dataset using data mining techniques. It focuses on classification of soil using various algorithms available. Another important purpose is to predict untested attributes using regression technique, and implementation of automated soil sample classification.

Jay Gholap

2012-05-01

351

Soil Organic Carbon dynamics in agricultural soils of Veneto Region  

Science.gov (United States)

One of the eight soil threats expressed in the European Commission's Thematic Strategy for Soil Protection (COM (2006)231 final) it's the decline in Soil Organic Matter (SOM). His preservation is recognized as with the objective to ensure that the soils of Europe remain healthy and capable of supporting human activities and ecosystems. One of the key goals of the strategy is to maintain and improve Soil Organic Carbon (SOC) levels. As climate change is identified as a common element in many of the soil threats, the European Commission (EC) intends to assess the actual contribution of the soil protection to climate change mitigation and the effects of climate change on the possible depletion of SOM. A substantial proportion of European land is occupied by agriculture, and consequently plays a crucial role in maintaining natural resources. Organic carbon preservation and sequestration in the EU's agricultural soils could have some potential to mitigate the effects of climate change, particularly linked to preventing certain land use changes and maintaining SOC stocks. The objective of this study is to assess the SOC dynamics in agricultural soils (cropland and grassland) at regional scale, focusing on changes due to land use. A sub-objective would be the evaluation of the most used land management practices and their effect on SOC content. This assessment aims to determine the geographical distribution of the potential GHG mitigation options, focusing on hot spots in the EU, where mitigation actions would be particularly efficient and is linked with the on-going work in the JRC SOIL Action. The pilot area is Veneto Region. The data available are coming from different sources, timing and involve different variables as: soil texture, climate, soil disturbance, managements and nutrients. The first source of data is the LUCAS project (Land Use/Land Cover Area Frame statistical Survey). Started in 2001, the LUCAS project aims to monitor changes in land cover/use and management of the EU territory by field observations of geo-referenced points. In 2009, a topsoil (0-30 cm) module was included to the survey and a subset of around 21,000 sites was sampled in 23 Member States. The second source is a soil survey monitoring pilot campaign carried in Veneto Region last year. The pilot campaign has been organized with the collaboration between JRC, University of Padova and ARPAV Veneto. The scope was to apply the LUCAS methodology to an experimental soil survey of 40 samples. The selection of the points to survey has been done on the basis of the LUCAS project related to Veneto Region, pedo-climatic and management unit conditions and the database on soils belonging to ARPAV Soil Unit, collected ante 2000. Data started to be investigated and permit to show changes in SOC content in a decade for different land use/cover and climatic areas. Through the bulk density data collected and the data already available from ARPAV library, it's possible to evaluate the Carbon stocks of Veneto region. Possible changes in Carbon can be related to land use changes and different strategies of management practices adopted over time.

Bampa, F. B.; Morari, F. M.; Hiederer, R. H.; Toth, G. T.; Giandon, P. G.; Vinci, I. V.; Montanarella, L. M.; Nocita, M.

2012-04-01

352

Lunar soil grain size distribution  

Science.gov (United States)

A comprehensive review has been made of the currently available data for lunar grain size distributions. It has been concluded that there is little or no statistical difference among the large majority of the soil samples from the Apollo 11, 12, 14, and 15 missions. The grain size distribution for these soils has reached a steady state in which the comminution processes are balanced by the aggregation processes. The median particle size for the steady-state soil is 40 to 130 microns. The predictions of lunar grain size distributions based on the Surveyor television photographs have been found to be quantitatively in error and qualitatively misleading.

Carrier, W. D., III

1973-01-01

353

Predicting hydrocarbon release from soil  

Energy Technology Data Exchange (ETDEWEB)

'Full text:' The remediation of hazardous chemicals from soils can be a lengthy and costly process. As a result, recent regulatory initiatives have focused on risk-based corrective action (RBCA) approaches. Such approaches attempt to identify the amount of chemical that can be left at a site with contaminated soil and still be protective of human health and the environment. For hydrocarbons in soils to pose risk to human heath and the environment, the hydrocarbons must be released from the soil and accessible to microorganisms, earthworms, or other higher level organisms. The sorption of hydrocarbons to soil can reduce the availability of the hydrocarbon to receptors. Typically in soils and sediments, there is an initial fast release of a hydrocarbon from the soil to the aqueous phase followed by a slower release of the remaining hydrocarbon to the aqueous phase. The rate and extent of slow release can influence aqueous hydrocarbon concentrations and the fate and transport of hydrocarbons in the subsurface. Once the fast fraction of the chemical has been removed from the soil, the remaining fraction of a chemical may desorb at a rate that natural mechanisms can attenuate the released hydrocarbon. Hence, active remediation may be needed only until the fast fraction has been removed. However, the fast fraction is a soil and chemical specific parameter. This presentation will present a tier I type protocol that has been developed to quickly estimate the fraction of hydrocarbons that are readily released from the soil matrix to the aqueous phase. Previous research in our laboratory and elsewhere has used long-term desorption (four months) studies to determine the readily released fraction. This research shows that a single short-term (less than two weeks) batch extraction procedure provides a good estimate of the fast released fraction derived from long-term experiments. This procedure can be used as a tool to rapidly evaluate the release and bioavailability of hydrocarbons in a contaminated soil. This knowledge can enhance the selection and determine the duration of a proper remediation strategy. Information will be provided on the correlation of the results from this protocol to the results of chemical loss in contaminated soil bioremediation systems. This research has been completed, the data is currently being analyzed and the results will be fully evaluated by early 2002. As a result, the protocol and potential applications to field decisions will be presented and discussed. (author)

Poppendieck, D.G.; Loehr, R.C. [Univ. of Texas at Austin, Austin, Texas (United States)

2002-06-15

354

Biological soil treatment; Biologische Bodenbehandlung  

Energy Technology Data Exchange (ETDEWEB)

Biological soil rehabilitation methods are state of the art when it comes to decontaminating mineral oil contaminated soils. They are used successfully both in situ and ex situ. Optimising the environmental and operating conditions permits accelerating the reaction processes the pollutants undergo in the soil as well as increasing the turnover rate. [German] Biologische Bodenreinigungsverfahren sind fuer die Dekontamination mineraloelkontaminierter Boeden Stand der Technik. Sie werden sowohl in situ als auch ex situ mit Erfolg betrieben. Eine Beschleunigung der Umsetzungsvorgaenge der Schadstoffe im Boden und eine Erhoehung der Umsatzleistung kann u.a. durch Optimierung der Milieu- und Betriebsbedingungen erfolgen. (orig.)

Hupe, K.; Stegmann, R. [Ingenieurbuero fuer Abfallwirtschaft Prof. R. Stegmann und Partner, Hamburg (Germany)

1999-07-01

355

Applications of visual soil evaluation  

DEFF Research Database (Denmark)

Working Group F “Visual Soil Examination and Evaluation” (VSEE) was formed over 30 years ago within the International Soil & Tillage Research Organisation (ISTRO) on the initiative of Tom Batey. The objectives of the Working Group are to stimulate interest in field methods of visual-tactile soil assessment, to encourage their wider use and to foster international cooperation. The previous main meeting of the group in 2005 at Peronne, France, brought together, for the first time, a group of soil scientists who had each developed a method to evaluate soil structure directly in the field (Boizard et al., 2006). Ten visual and tactile methods were used to assess soil structure on the same soil. This stimulated significant ongoing cooperation between participants and several authors have since modified and developed their procedures (Mueller et al., 2009 and Shepherd, 2009). Cooperation also led to the re-development of the Peerlkamp numeric method of assessment of soil structure into the Visual Evaluation of SoilStructure (VESS) spade test (Ball et al., 2007 and Guimarães et al., 2011). The meeting also recommended further cooperation between members of the Working Group. The evaluation of subsoil structure was discussed at an intermediate meeting of the group in January 2009 at Edinburgh. A common theme from the two earlier meetings was to develop both topsoil and subsoil methods to allow identification of conditions where modification of structure was required, possibly by use of a harmonized scale. Other recommendations were to include coarse textured soils, to consider controlled traffic, to relate sampling location to vegetation and crop conditions and to relate the results of visual evaluation of soil to crop performance. This latter has already been achieved with the VSA test from New Zealand which has now been extended to the assessment of environmental conditions such as potential greenhouse gas emissions, nutrient loss into groundwater and waterways and carbon sequestration (Shepherd, 2009). The meeting was held on 16th–18th May 2011 at Aarhus University Flakkebjerg Research Centre, Denmark. Twenty-six delegates attended from 10 countries – France, Denmark, Ireland, UK, New Zealand, Australia, USA, Sweden, Germany and Norway. This Special Issue of Soil and Tillage Research includes papers presented at the meeting, together with one paper related to the activity of the Working Group since the meeting in Peronne.

Ball, Bruce C; Munkholm, Lars Juhl

2013-01-01

356

Soil Delivery to Phoenix Oven  

Science.gov (United States)

This image shows a view from NASA's Phoenix Mars Lander's Stereo Surface Imager's left eye after delivery of soil to the Thermal and Evolved-Gas Analyzer (TEGA), taken on the 12th Martian day after landing (Sol 12, June $6, 2008). Soil is visible on both sides of the open doors of TEGA's #4 oven. Sensors inside the device indicate no soil passed through the screen and into the oven. The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

2008-01-01

357

Soil Albedo in Relation to Soil Color, Moisture and Roughness  

Science.gov (United States)

Land surface albedo is the ratio of reflected to incident solar radiation. It is a function of several surface parameters including soil color, moisture, roughness and vegetation cover. A better understanding of albedo and how it changes in relation to variations in these parameters is important in order to help improve our ability to model the effects of land surface modifications on climate. The objectives of this study were (1) To determine empirical relationships between smooth bare soil albedo and soil color, (2) To develop statistical relationships between albedo and ground-based thematic mapper (TM) measurements of spectral reflectances, (3) To determine how increased surface roughness caused by tillage reduces bare soil albedo and (4) To empirically relate albedo with TM data and other physical characteristics of mixed grass/shrubland sites at Walnut Gulch Watershed. Albedos, colors and spectral reflectances were measured by Eppley pyranometer, Chroma Meter CR-200 and a Spectron SE-590, respectively. Measurements were made on two field soils (Gila and Pima) at the Campus Agricultural Center (CAC), Tucson, AZ. Soil surface roughness was measured by a profile meter developed by the USDA/ARS. Additional measurements were made at the Maricopa Agricultural Center (MAC) for statistical model testing. Albedos of the 15 smooth, bare soils (plus silica sand) were determined by linear regression to be highly correlated (r^2 = 0.93, p > 0.01) with color values for both wet and dry soil conditions. Albedos of the same smooth bare soils were also highly correlated (r^2>=q 0.86, p > 0.01) with spectral reflectances. Testing of the linear regression equations relating albedo to soil color and spectral reflectances using the data from MAC showed a high correlation. A general nonlinear relationship given by y = 8.366ln(x) + 37.802 r^2 = 0.71 was determined between percent reduction in albedo (y) and surface roughness index (x) for wet and dry Pima and Gila field soils. Measurements of albedo, color and spectral reflectance at the Walnut Gulch Watershed indicated that albedo values were highly correlated with percent rock & gravel, color value and reflectance data (TM bands 1-4).

Fontes, Adan Fimbres

358

Soil survey - a basis for european soil protection  

International Nuclear Information System (INIS)

The information available on soils varies greatly from country to country. In view of the fact that, together with water, soils represent the most important natural resource in the EC, it is recommended that steps should be taken to ensure a reasonable level of information for all countries and that emphasis be placed on assembling an adequate database. Such information is fundamental to future land use and environmental protection

359

Soils apart from equilibrium – consequences for soil carbon balance modelling  

Directory of Open Access Journals (Sweden)

Full Text Available Many projections of the soil carbon sink or source are based on kinetically defined carbon pool models. Parameters of these models are often determined in a way that the steady state of the model matches observed carbon stocks. The underlying simplifying assumption is that observed carbon stocks are near equilibrium. This assumption is challenged by observations of very old soils that do still accumulate carbon. In this modelling study we explored the consequences of the case where soils are apart from equilibrium. Calculation of equilibrium states of soils that are currently accumulating small amounts of carbon were performed using the Yasso model. It was found that already very small current accumulation rates cause big changes in theoretical equilibrium stocks, which can virtually approach infinity. We conclude that soils that have been disturbed several centuries ago are not in equilibrium but in a transient state because of the slowly ongoing accumulation of the slowest pool. A first consequence is that model calibrations to current carbon stocks that assume equilibrium state, overestimate the decay rate of the slowest pool. A second consequence is that spin-up runs (simulations until equilibrium overestimate stocks of recently disturbed sites. In order to account for these consequences, we propose a transient correction. This correction prescribes a lower decay rate of the slowest pool and accounts for disturbances in the past by decreasing the spin-up-run predicted stocks to match an independent estimate of current soil carbon stocks. Application of this transient correction at a Central European beech forest site with a typical disturbance history resulted in an additional carbon fixation of 5.7±1.5 tC/ha within 100 years. Carbon storage capacity of forest soils is potentially much higher than currently assumed. Simulations that do not adequately account for the transient state of soil carbon stocks neglect a substantial amount of current carbon accumulation.

T. Wutzler

2006-10-01

360

Soils - Part 6: Phosphorus and Potassium in the Soil  

Science.gov (United States)

This lesson explains the importance of phosphorus fixation and describes methods for applying phosphorus and the advantages (and disadvantages) of each. It also describes the three forms of potassium and how form determines availability of potassium to plants.[This lesson, as well as the other nine lessons in the Soils series, is taken from the "Soils Home Study Course," published in 1999 by the University of Nebraska Cooperative Extension.

 
 
 
 
361

Salt overload: How quickly does road salt move from road to groundwater to stream in Baltimore County, MD and what are the effects on soil, groundwater, and stream chemistry?  

Science.gov (United States)

The portion of the landscape covered by roads and other impervious surfaces has increased over the last 50 years. Concurrently, application of road salt, primarily sodium chloride (NaCl), as a de-icer has increased in areas of North America with regular ice and snowfall events. Over the last 10 - 15 years, numerous investigators reported that decades of road salt application has resulted in growing concentrations of sodium and chloride in groundwater and surface water. These road salt-derived elements are present at elevated levels in the surface and groundwaters of impacted watersheds year round. An understudied aspect of road salt impacts has been the role that stormwater management basins (SMBs) play in altering the timing and location of road salt loading to urban and suburban groundwater-surface water systems. SMBs have become common in construction and development over the last 15-20 years. One of the major goals of SMBs is to decrease direct runoff from impervious surfaces to streams by redirecting that runoff into shallow groundwater and thus reducing the flashiness of streams in urban and suburban areas. An unintended consequence of SMBs is that road salt runoff from impervious surfaces is focused into the SMBs and loaded into the vadose zone and shallow groundwater in the winter and then exported to surface water throughout the year. As part of an onging project in a suburb northwest of Baltimore, MD, water samples were collected several times a year from groundwater below two SMBs, a shallow groundwater aquifer downgradient of the SMBs, and a second-order stream for which the aquifer provides baseflow. The major elemental chemistry of the samples was measured. Conductivity and water level loggers were installed to collect data in wells and surface water between grab sampling events. The logger records will be analyzed using spatio-temporal data mining techniques to extract important patterns in the data and to highlight and understand seasonal trends and storm events. A persistent groundwater plume of water with high NaCl concentrations is present below the SMBs and downgradient in the shallow groundwater aquifer. Concentrations vary seasonally with the highest concentrations in the winter and early spring. Na+ clearly interacts with the cation exchange complex (CEC) along a flowpath between the SMB and the stream. As a result, the Na:Cl ratio falls from 1:1 in groundwater below the SMBs to as low as ~1:10 and also seems to vary seasonally along the flowpath. Preliminary measurements of the CEC show that the Ca:Na ratio decreases by a factor of 2 - 5 in soil and aquifer materials affected by road salt. Preliminary strontium (Sr) isotope data indicate that groundwater and CEC within the road salt plumes are similar to Sr isotope values for seawater and are isotopically distinct from the relatively radiogenic natural weathering Sr isotope signal. Our findings indicate that SMBs increase the residence time of road salt in groundwater and stream systems with potential negative implications for ecosystems downgradient of SMBs.

Moore, J.; Sandosky, B.; McGuire, M.; Casey, R.; Snodgrass, J.; Lev, S. M.

2013-12-01

362

Soil CO2 Dynamics in a Tree Island Soil of the Pantanal: The Role of Soil Water Potential  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The Pantanal is a biodiversity hotspot comprised of a mosaic of landforms that differ in vegetative assemblages and flooding dynamics. Tree islands provide refuge for terrestrial fauna during the flooding period and are particularly important to the regional ecosystem structure. Little soil CO2 research has been conducted in this region. We evaluated soil CO2 dynamics in relation to primary controlling environmental parameters (soil temperature and soil water). Soil respiration was computed u...

Johnson, Mark S.; Couto, Eduardo Guimara?es; Pinto Jr, Osvaldo B.; Milesi, Juliana; Santos Amorim, Ricardo S.; Messias, Indira A. M.; Biudes, Marcelo Sacardi

2013-01-01

363

Soil Washing Experiment for Decontamination of Contaminated NPP Soil  

International Nuclear Information System (INIS)

The preliminary experiment was performed to obtain the operating conditions of soil washing decontamination process such as decontamination agent, decontamination temperature, decontamination time and ratio of soil and decontamination agent. To estimate decontamination efficiency, particle size of soil was classified into three categories; ? 2.0 mm, 2.0 ? 0.21 mm and ? 0.21 mm. Major target of this experiment was decontamination of Cs-137. The difference of decontamination efficiency using water and neutral salts as decontamination agent is not high. It is concluded that the best temperature of decontamination agent is normal temperature and the best decontamination time was about 60 minutes. And the best ratio of soil and decontamination agent is 1:10. In case of Cs decontamination for fine soils, the decontamination results using neutral salts such as Na2CO3 and Na3PO4 shows some limits while using strong acid such as sulfuric acid or hydrochloric acid shows high decontamination efficiency (?90%). But we conclude that decontamination using strong acid is also inappropriate because of the insufficiency of decontamination efficiency for highly radioactive fine soils and the difficulty for treatment of secondary liquid waste. It is estimated that the best decontamination process is to use water as decontamination agent for particles which can be decontaminated to clearance level, after particle size separation. (author particle size separation. (authors)

364

Occurrence of entomopathogenic fungi in arable soil  

Directory of Open Access Journals (Sweden)

Full Text Available Samples of soil were taken from arable field and from balk. Larvae of Galleria mellonella and Ephestia kühniella were used as an "insect bait" for isolation of entomopathogenic fungi from soil. Metarhizium anisopliae and Paecilomyces fumosoroseus were isolated from both kind of soil. but Beauveria bassiana was present only in soil taken from balk.

Ryszard Mi?tkiewski

1993-06-01

365

Getting a Feel for Soils - Lab  

Science.gov (United States)

This is a lab activity in which students start to put together what they have learned as separate soil attributes in the context of the world they know. This activity involves hypothesizing geologic and soils relationships using state and world maps, conducting texture-by-feel tests, reflecting on the definition of 'soil', and evaluating soil granulometric methods.

Fadem, Cynthia

366

The role of biological soil crusts in soil moisture dynamics in two semiarid ecosystems with contrasting soil textures  

Science.gov (United States)

The interplant soil surfaces in most arid and semiarid ecosystems are covered by biological soil crusts (BSCs). These crusts regulate water inputs and losses through soils and play major roles in local hydrological regimes. In recent years, the role of BSCs in infiltration and runoff has gained increasing importance and better knowledge of their effects on these processes has been acquired. However, the role of BSCs in other important components of the water balance, such as evaporation or soil moisture has hardly been studied, so their effects on these processes remain unknown. The aim of this study was to explore the influence of BSCs on soil moisture regimes in the top layer of the soil in two semiarid ecosystems in SE Spain with different particle-size distributions. At both study sites, soil moisture was monitored at 0.03 and 0.10 m under two types of BSCs, a cyanobacteria-dominated BSC and a lichen-dominated BSC, and in adjacent soils where they had been removed. Our results showed that during wet soil periods, removal of BSCs led to decreased soil moisture, especially in the upper layer (0.03 m), compared to soils covered by BSCs. Decrease in soil moisture was more noticeable after removal of lichens than cyanobacterial BSCs, and more so in fine than in coarse-textured soils. Soil water loss was also generally faster in soils with no BSCs than in soils covered by them. However, no difference was found in soil moisture under either crusted or scalped soils during soil drying periods. The type of BSC influenced soil moisture differently depending on soil water content. During wet soil periods, soil water loss was faster and soil moisture lower under cyanobacterial than under lichen BSCs. On the contrary, during soil drying periods, soils covered by lichens lost water faster and showed lower moisture than those covered by cyanobacteria. Our results show the major role of the presence of BSCs, as well as the types, in soil water content in semiarid ecosystems.

Chamizo, Sonia; Cantón, Yolanda; Lázaro, Roberto; Domingo, Francisco

2013-05-01

367

Effects of environmental factors and soil properties on topographic variations of soil respiration  

Directory of Open Access Journals (Sweden)

Full Text Available Soil respiration rates were measured along different parts of a slope in (a an evergreen forest with common brown forest soil and (b a deciduous forest with immature soil. The effects of soil temperature, soil moisture and soil properties were estimated individually, and the magnitudes of these effects in the deciduous and evergreen forests were compared. In the evergreen forest with common brown forest soil, soil properties had the greatest effect on soil respiration rates, followed by soil moisture and soil temperature. These results may be explained by the fact that different soil properties matured within different environments. It can be argued that the low soil respiration rates in the low parts of the slope in the evergreen forest resulted from soil properties and not from wet soil conditions. In the deciduous forest, soil respiration rates were more strongly affected by soil moisture and soil temperature than by soil properties. These effects were likely due to the immaturity of the forest soil.

K. Tamai

2010-03-01

368

Impact of soil properties on selected pharmaceuticals adsorption in soils  

Science.gov (United States)

The presence of human and veterinary pharmaceuticals in the environment has been recognized as a potential threat. Pharmaceuticals may contaminate soils and consequently surface and groundwater. Study was therefore focused on the evaluation of selected pharmaceuticals adsorption in soils, as one of the parameters, which are necessary to know when assessing contaminant transport in soils. The goals of this study were: (1) to select representative soils of the Czech Republic and to measure soil physical and chemical properties; (2) to measure adsorption isotherms of selected pharmaceuticals; (3) to evaluate impact of soil properties on pharmaceutical adsorptions and to propose pedotransfer rules for estimating adsorption coefficients from the measured soil properties. Batch sorption tests were performed for 6 selected pharmaceuticals (beta blockers Atenolol and Metoprolol, anticonvulsant Carbamazepin, and antibiotics Clarithromycin, Trimetoprim and Sulfamethoxazol) and 13 representative soils (soil samples from surface horizons of 11 different soil types and 2 substrates). The Freundlich equations were used to describe adsorption isotherms. The simple correlations between measured physical and chemical soil properties (soil particle density, soil texture, oxidable organic carbon content, CaCO3 content, pH_H2O, pH_KCl, exchangeable acidity, cation exchange capacity, hydrolytic acidity, basic cation saturation, sorption complex saturation, salinity), and the Freundlich adsorption coefficients were assessed using Pearson correlation coefficient. Then multiple-linear regressions were applied to predict the Freundlich adsorption coefficients from measured soil properties. The largest adsorption was measured for Clarithromycin (average value of 227.1) and decreased as follows: Trimetoprim (22.5), Metoprolol (9.0), Atenolol (6.6), Carbamazepin (2.7), Sulfamethoxazol (1.9). Absorption coefficients for Atenolol and Metoprolol closely correlated (R=0.85), and both were also related to absorption coefficients of Carbamazepin (R=0.67 and 0.68). Positive correlation was found between Trimetoprim absorption coefficients and Atenolol, Metoprolol or Carbamazepin absorption coefficients. The negative relationship was found between absorption coefficients of Sulfomethoxazol and Clarithromycin (R=-0.80). Sulfamethoxazol absorption coefficient was negatively related to pH_H2O, pH_KCL or sorption complex saturation and positively to the hydrolytic acidity or exchangeable acidity. Trimetoprim absorption coefficient was positively related to the oxidable organic carbon content, cation exchange capacity, basic cation saturation or silt content and negatively to particle density or sand content. Clarithromycin absorption coefficient was positively related to pH_H2O, pH_KCL, CaCO3 content, basic cation saturation or sorption complex saturation and negatively to hydrolytic acidity or exchangeable acidity. Atenolol and Metoprolol absorption coefficients were positively related to the oxidable organic carbon content, cation exchange capacity, basic cation saturation, salinity, clay content or silt content, and negatively to the particle density or sand content. Finally Carbamazepin absorption coefficient was positively related to the oxidable organic carbon content, cation exchange capacity or basic cation saturation, and negatively to the particle density or sand content. Evaluated pedotransfer rules for different pharmaceuticals included different sets of soil properties. Absorption coefficients could be predicted from: the hydrolytic acidity (Sulfamethoxazol), the oxidable organic carbon content (Trimetoprim and Carbamazepin), the oxidable organic carbon content, hydrolytic acidity and cation exchange capacity (Clarithromycin), the basic cation saturation (Atenolol and Metoprolol). Acknowledgement: Authors acknowledge the financial support of the Czech Science Foundation (Project No. 13-12477S).

Kodesova, Radka; Kocarek, Martin; Klement, Ales; Fer, Miroslav; Golovko, Oksana; Grabic, Roman; Jaksik, Ondrej

2014-05-01

369

Soil quality assessment using fuzzy modeling  

Directory of Open Access Journals (Sweden)

Full Text Available Maintaining soil productivity is essential if agriculture production systems are to be sustainable, thus soil quality is an essential issue. However, there is a paucity of tools for measurement for the purpose of understanding changes in soil quality. Here the possibility of using fuzzy modeling theory as a means to address the problem of soil quality assessment is considered. For soil quality assessment, two general types of fuzzy soil quality indicators potentially could be defined. The theoretical consideration of this process is illustrated with an example. Results indicate that the fuzzy multi-attributive approach could be effectively utilized as a tool leading to better understanding soil quality.

D. Kurtener

2008-12-01

370

[Research advance in soil organic phosphorus].  

Science.gov (United States)

Soil organic phosphorus (P) plays an important role in the material cycling in agro-ecosystem, and its research is vital for understanding the characteristics of P cycle in soil-plant system. This paper summed up the latest research achievements at home and abroad about soil organic P content and its affecting factors, soil organic P forms, their fractionation and determination methods, effects of fertilization on soil organic P forms, and mineralization of soil organic P. The existing problems in soil organic P study and its hotspots in future were also discussed. PMID:15707340

Zhao, Shaohua; Yu, Wantai; Zhang, Lu; Shen, Shanmin; Ma, Qiang

2004-11-01

371

National Soil DataBase (NSDB)  

Science.gov (United States)

The Canadian Soil Information System (CanSIS) hosts the National Soil DataBase (NSDB), a set of data files including soil, landscape, and climatic variables for all of Canada. The NSDB includes GIS coverages for several scales, in addition to listing characteristics for each soil series. Principle data holdings include National Ecological Framework (EcoZones, EcoRegions, and EcoDistricts); Soil Map of Canada/ Land Potential DataBase (LPDB); Agroecological Resource Areas (ARAs); Soil Landscapes of Canada (SLC); Canada Land Inventory (CLI); and Detailed Soil Surveys. Most datasets are available for free at the Website; files are in ARC/INFO Export format only.

2008-08-08

372

Crusting susceptibility in some allic Colombian soils  

International Nuclear Information System (INIS)

Many lab methods were used: dry and water soil aggregates stability, instability index and erosion index and their results were related with soil characteristics like texture, Fe and Al oxides and organic matter. Soil samples collected within 0-2.5 and 2.5-5 cm of the soil surface came from terrains with many kinds of both forest and savanna intervened systems. Those results were analyzed like a completely randomized designed. It was found that significative changes in oxides content could increase soil-crusting susceptibility unless soil humus was up to was up to 4%. In this sense, pastures or its rotation with rice and leguminous offer a best alternative for intervening these natural systems. Intensive land husbandry or monocultures with low stubble soil incorporation caused an increase in physical instability at the top of soil. Dry soil stability test and instability index were most adequate for these soils

373

Scientists Sift Through Urban Soils  

Science.gov (United States)

City soil gets tramped on, dumped on, and pushed around, but some soil scientists are carefully examining what is underfoot in urban areas. During a 3 May session on urban soils at the European Geosciences Union's General Assembly in Vienna, Austria, scientists discussed various aspects of city dirt. In a presentation about the large amount of rubble from buildings that were bombed during World War II, Beate Mekiffer with the Soil Protection Group at the Berlin Institute of Technology, Germany, noted that the sulfate concentration in Berlin's upper aquifer has increased continuously for decades. Many areas in Berlin now exceed a 240-milligram-per-liter “precaution value” for sulfate in drinking water, according to Mekiffer.

Showstack, Randy

2010-05-01

374

Immobilization experiment of soil wastes  

International Nuclear Information System (INIS)

The amount of 4,500 drums of soil waste are temporarily stored in KAERI. In order to develop a technology for safe treatment of the soil waste, a number of tests were performed by applying cement and polymer as solidifies. Immobilization specimens were adequately made by mixing soil waste with cement or polymer. Compressive strength and leaching tests were performed in order to see the fulfillment to standard of disposal following the storage. A compressive strength, about 5,300psi was obtained from both solidifies of cement containing 40% of soil waste and polymer containing 60%. The obtained leaching index was larger than 11, which was satisfied with the relevant standard. It was shown that the integrity of the solidified waste much depends on homogenization in solidifying process and hardness of the specimen. Volume reduction of solidified waste with polymer was better than that of cement by 20%

375

Radionuclide migration studies in soil  

International Nuclear Information System (INIS)

In this work a brief description about retention and migration parameters of radionuclides in soil, including main methods to determine the distribution coefficient (K) are given. Some of several factors that can act on the migration are also mentioned. (author)

376

Ash in the Soil System  

Science.gov (United States)

Ash is the organic and inorganic residue produced by combustion, under laboratory and field conditions. This definition is far away to be accepted. Some researchers consider ash only as the inorganic part, others include also the material not completely combusted as charcoal or biochar. There is a need to have a convergence about this question and define clear "what means ash". After the fire and after spread ash onto soil surface, soil properties can be substantially changed depending on ash properties, that can be different according to the burned residue (e.g wood, coal, solid waste, peppermill, animal residues), material treatment before burning, time of exposition and storage conditions. Ash produced in boilers is different from the produced in fires because of the material diferent propertie and burning conditions. In addition, the ash produced in boilers is frequently treated (e.g pelletization, granulation, self curing) previously to application, to reduce the negative effects on soil (e.g rapid increase of pH, mycorrhiza, fine roots of trees and microfauna). These treatments normally reduce the rate of nutrients dissolution. In fires this does not happen. Thus the implications on soil properties are logically different. Depending on the combustion temperature and/or severity, ash could have different physical (e.g texture, wettability) and chemical properties (e.g amount and type of total and leached nutrients) and this will have implications on soil. Ash can increase and decrease soil aggregation, wettablity and water retention, bulk density, runoff and water infiltration. Normally, ash increases soil pH, Electrical Conductivity, and the amount of some basic nutrients as calcium, magnesium, sodium and potassium. However it is also a potential source of heavy metals, especially if ash pH is low. However the effect of ash on soil in space and time depends especially of the ash amount and characteristics, fire temperature, severity, topography, aspect, climate/meteorological conditions after the ash spread/fire and soil background characteristics. In addition, after the fire heating can change soil original properties increasing the complexity of the ash effects on soil properties. After fire, ash is highly dynamic and very easily transported by wind until the first rains. When wetted, ash compacts and binds onto soil surface, and wind has low capacity to transport it. The post-rain ash dynamic is influenced by water erosion (in slope areas), infiltration into soil profile and vegetation recuperation. This means that ash produced in one place will have implications in other areas, including not burned areas (e.g wind transport and water erosion). This is a clear indication that ash effects go much further than the fire affected area. Due the heterogeneity of soil and ash properties and their dynamic across the landscape, the impacts of ash on soil system can be diverse, producing a mosaic of different effects and responses after ash treatment and/ or fire. In this communication it will be presented and discussed the advances and scientific development of ash effects and dynamic in soil system.

Pereira, P.

2012-04-01

377

Soil decontamination and radiation monitoring  

International Nuclear Information System (INIS)

Mechanism of Cs adsorption in soils is presented. The present status of contaminated farmlands in Fukushima, Japan, from the meltdown Nuclear Power Plants is explained. To promote remediation of the contaminated farmlands, the authors propose to continuously monitor air dose at point referred to as hotspots in rural areas and radiation dose in soils by using field monitoring system (FMS) with a waterproof radiation sensor. The outline of an FMS, a useful tool for remediation of the radionuclide contaminated farmland, is explained. It consists of three components: a field router, data logger, and soil/meteorological sensors including a radiation sensor whose function is to collect data from the data logger and then send to the data server over the internet, and the data logger stores the data. The system for real time data collection from remote agricultural fields is now installed in situ soil monitoring in Iidate village, Fukushima. (S. Ohno)

378

Structure and composition of soils  

Directory of Open Access Journals (Sweden)

Full Text Available This paper presents a study of soils structure and composition using up to date technique, such as scanning electronic microscopy, atomic force microscopy, X-ray diffraction, X-ray fluorescence, as well as some other characterization methods. It was shown that soil particles have porous structure and dimensions in the range from several millimeters to several hundreds of nanometers and consist of different minerals such as kaolin, quartz and feldspate.

Snežana Nenadovi?

2010-12-01

379

Microbiological research of soil bioremediation  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Bioremediation is the application of biological processes for the clean up of pollutants present in the environment. The scope of the review encompasses the following subjects: biodegradation of various polymeric and natural origin compounds; the applications of microorganisms to laboratory scale and field scale soil bioremediation, with a focus on petroleum hydrocarbons; bioaugmentation and characterization of microbial communities; the factors affecting soil bioremediation processes includi...

Kale?diene?, Lilija

2009-01-01

380

Soil roughness and overland flow  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Soil surface roughness affects surface depression storage, water infiltration, overland flow velocity as well as overland flow organisation. This paper attempts to give an overview of our knowledge of the effects of roughness on surface runoff and to indicate areas where further research is most needed. The relationship between soil surface roughness and depression storage is relatively well understood. On the other hand, few studies exist on the relationship between roughness and the infiltr...

Govers, Gerard; Takken, Ingrid; Helming, Katharina

2000-01-01

 
 
 
 
381

Submicromorphology of soil magnetic fractions  

Science.gov (United States)

The spatial and vertical distribution patterns of ferromagnetic particles in soddy-podzolic and chernozemic soils subjected to technogenic loads have been studied. A classification of soil magnetic particles according to their morphological features is suggested. It takes into account the shape and the character of the particles’ surface, which are specified by the genesis of the particles, and may be used for diagnostic purposes.

Zagurskii, A. M.; Ivanov, A. V.; Shoba, S. A.

2009-09-01

382

Testing oils in antarctic soils  

International Nuclear Information System (INIS)

The resident seals, whales and penguins in Antarctica's Ross Sea region have only environmentally friendly ways of getting around. In contrast, wherever humans go in the Antarctic and whatever they do, be it research, tourism or fishing, they need fuel for their planes, icebreaker ships, land vehicles and generators. Because of this, petroleum hydrocarbons are the most likely source of pollution in the Antarctic. Accidental oil spills often occur near scientific stations, where storage and refuelling of aircraft and vehicles can result in spills. Spills also occur as a consequence of drilling activities. Dr Jackie Aislabie, a microbiologist from the New Zealand government's research company Landcare Research, is leading a program aimed at understanding how oil spills impact on Antarctic soils. The properties of pristine soils were compared with oil-contaminated soil at three locations: Scott Base, Marble Point and in the Wright Valley at Bull Pass. Soils in the Scott Base area are impacted by the establishment and continuous habitation of the base over 40 years, and a hydrocarbon-contaminated site was sampled near a former storage area for drums of mixed oils. Soil sampled from Marble Point was taken from near the old Marble Point camp, which was inhabited from 1957 to about 1963. Oil stains were visible on the soil surface, and are assumed to have been there for more than 30 years. The samples selected for analysis from the Wright Valley came from a spill site near Bright Valley came from a spill site near Bull Pass that occurred during seismic bore-hole drilling activities in 1985. The contamination levels ranged from below detection to just over 29,000 ?g/g of soil. Descriptions and analyse results are included into a Geographic Information System and associated soils database

383

European soil sampling guidelines for soil pollution studies.  

Science.gov (United States)

The soil sampling guidelines used in European countries (ESSG), as kindly provided by the national institutions which participated in the project, have been recorded, studied, evaluated and presented in this paper. The aim has been to ascertain what soil sampling guidelines exist in Europe; to detect similarities and differences (comparable results), advantages and deficiencies; to identify incompatible strategies and evaluate how methodologies might affect data quality; to investigate sources of deviations or uncertainties; to improve comparability and representativeness of soil sampling; to investigate the need for harmonised sampling guidelines; and to develop suggestions for standard operating procedures (SOP). Soil sampling guidelines throughout Europe differ as to whether they are applied by law, or used throughout the country. In some countries these are ISO/DIS related or based (ISO 10381-1, 1995; ISO 10381-2, 1995), or are produced by a scientific society or a standardisation body. As far as sampling strategy is concerned, not all sampling guidelines clearly describe the sampling scale, the specifications for contamination risk precautions, the sampling plan and protocol structure and the pre-analysis treatment of the soil samples. The purpose for sampling, in descending order of frequency, is soil pollution, soil fertilisation, general soil monitoring, background risk assessment, or else it is not specified. The majority of countries do not sample the top organic matter separately. Sampling depth is either related to the morphogenetic horizon or to ad hoc sampling depth, which is not specified in all cases. They suggest mass- and volume-related soil sampling, while the sampling pattern is not presented in all national guidelines. The criteria for area, site, unit, sub-unit, and point selection are mainly based on pedology and land use, following the history and pre-screening information or geology, or is site related. Some guidelines suggest the division of sampling units into sub-units. The sampling pattern is mainly grid sampling, grid and random sampling, or not mentioned. Sampling density inside the sampling unit either varies greatly or it is not mentioned, while the size of the sampling unit varies widely. Most guidelines require the collection of composite instead of simple samples, while some prefer sampling soil profiles. In the European SSG many technical details and steps are either not defined or vary, while in the pre-analysis treatment quality assurance (QA) and quality control (QC) approaches are used either both in the lab and in the field, or only in the field, or are not mentioned. The common points and the points in which harmonisation could be started or achieved are discussed. PMID:11213188

Theocharopoulos, S P; Wagner, G; Sprengart, J; Mohr, M E; Desaules, A; Muntau, H; Christou, M; Quevauviller, P

2001-01-01

384

Soil as a filter for groundwater quality  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The filtering function of soil is an important ecosystem service for groundwater and surface water protection. The efficiency of soils as a filter depends on the behaviour of pollutants in the soil and the hydrological transport processes. This paper aims to identify knowledge gaps in processes influencing pollutant behaviour in soils and their potential transport to groundwater. Currently most soil-filter function research is approached from two disciplines, one originating from agronomical...

Keesstra, S. D.; Geissen, V.; Mosse, K.; Piiranen, S.; Scudiero, E.; Leistra, M.; Schaik, L.

2012-01-01

385

Intercropping and its implications for soil management  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Preface Management of the soil encompasses a wide range of practices with the express purpose of improving the capability of the soil to perform the various functions. Improvement in soil management practices will result in increased soil functionality and will be realized only if these practices are based on scientific principles. In assembling this book, we had two primary goals. The first goal was to gather the information about the emerging challenges in soil management from a number of...

Walker, S.; Stigter, C. J.; Ofori, E.; Kyei-baffour, N.

2011-01-01

386

Soil Ecosystem Management in Birdlime Utilization  

Directory of Open Access Journals (Sweden)

Full Text Available The article deals with the management of material composition of the soil ecosystem, offers the technology and the technical solution for biological, inorganic substances and pollutants dispersal, passivation of soil pollutants at the depth of the current anthropogenic illuviation of 30–60 cm, works out the device for soil application of substances by rotary inter-soil cultivation providing soil and landscape conditioning.

Mohammed A. Bazgiev

2012-07-01

387

Davis Soil Moisture and Temperature Station Protocol  

Science.gov (United States)

The purpose of this resource is to log soil data using a Davis soil moisture and temperature station. Soil moisture and temperature sensors are installed at multiple depths and a station is set up to measure and record measurements at 15 minute intervals. These measurements are transferred to your school.s computer and then submitted to GLOBE via email data entry. Gravimetric soil moisture measurements must be taken to develop calibration curves for the soil moisture sensors.

The GLOBE Program, University Corporation for Atmospheric Research (UCAR)

2003-08-01

388

Diffusion coefficient of 137Cs in soil  

International Nuclear Information System (INIS)

In this paper we have studied, experimentally and theoretically, vertical distribution of 137Cs in uncultivated soil [1]. The results of 137Cs measurements in the soil of surroundings of Kragujevac are given. The samples of soil are taken from seven locations, chosen to investigate different types of soil. After the proper preparation, the measuring of activity of the samples is done with gamma- spectroscopy. Experimentally, we have determined the diffusion coefficient for different types of the soil. (author)

389

Brazilian Cerrado soil Actinobacteria ecology.  

Science.gov (United States)

A total of 2152 Actinobacteria strains were isolated from native Cerrado (Brazilian Savannah) soils located in Passos, Luminárias, and Arcos municipalities (Minas Gerais State, Brazil). The so