WorldWideScience
1

Depleted soil carbon and nitrogen pools beneath impervious surfaces  

International Nuclear Information System (INIS)

Urban soils and vegetation contain large pools of carbon (C) and nitrogen (N) and may sequester these elements at considerable rates; however, there have been no systematic studies of the composition of soils beneath the impervious surfaces that dominate urban areas. This has made it impossible to reliably estimate the net impact of urbanization on terrestrial C and N pools. In this study, we compared open area and impervious-covered soils in New York City and found that the C and N content of the soil (0–15 cm) under impervious surfaces was 66% and 95% lower, respectively. Analysis of extracellular enzyme activities in the soils suggests that recalcitrant compounds dominate the organic matter pool under impervious surfaces. If the differences between impervious-covered and open area soils represent a loss of C and N from urban ecosystems, the magnitude of these losses could offset sequestration in other parts of the urban landscape. - The soils beneath impervious surfaces are depleted in C and N, which may have implications for the energy and nutrient balance of urban ecosystems.

2

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

3

Rural impervious surfaces extraction from Landsat 8 imagery and rural impervious surface index  

Science.gov (United States)

There is an increasing need to understand pattern and growth of impervious surfaces in rural regions. However, studies using remote sensing of impervious surfaces have often focused on mapping impervious surfaces in urban regions with less emphasis placed on the rural impervious surfaces. In this paper, we proposed a new index, Rural Impervious Surface Index (RISI) by taking advantage of narrow spectral bands of Landsat 8 OLI for estimating impervious surfaces within rural land covers. This index is based on the combination of Normalized Difference Built-up Index (NDBI), Soil Adjusted Vegetation Index (SAVI) and Soil Index (SI). Respectively, these represent the three major rural land covers components: impervious surfaces, vegetation, and soil. The index was further used for estimating fraction of impervious surfaces using fuzzy KNN classifier. The performance of this technique was also compared with Linear Spectral Mixture Analysis (LSMA). Our results showed that RISI could accurately detect spatial pattern of rural impervious surfaces due to the suppressing background noise and minimizing spectral confusion. Accuracy assessment revealed that incorporation of RISI with fuzzy KNN classification generates higher correlation coefficient, lower root mean square and systematic error compared to the LSMA technique.

Zheng, Xinyu; Yu, Zhoulu; Ao, Weijiu; Wang, Youfu; Tahmassebi, Amir Reza; You, Shucheng; Deng, Jinsong; Wang, Ke

2014-11-01

4

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

5

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

6

A comparison study of impervious surfaces estimation using optical and SAR remote sensing images  

Science.gov (United States)

The estimation of impervious surface area (ISA) is becoming increasingly important because of its environmental and socio-economic significance. However, accurate ISA estimation remains challenging due to the diversity of impervious materials, as well as the occurrence of clouds in subtropical humid areas. In order to address these challenges and provide an accurate estimation of ISA in cloudy areas, it is advantageous to use both optical and microwave remote sensing which can penetrate cloud coverage. Our study aims to conduct a comprehensive comparison between these two data sources and between different methods for mapping ISA. Both the classification results and accuracy assessment provide a better understanding about the differences between Landsat ETM+ and ENVISAT ASAR images and between artificial neural network (ANN) and support vector machine (SVM) classifier for estimating the impervious surfaces. The comparison demonstrates that ETM+ images alone provide a better ISA estimation (OA: about 90%; Kappa: about 0.88) than the estimation from ASAR images alone (OA: about 85%; Kappa: about 0.77). Additionally, the experiment indicates that SVM should be a better choice for ISA estimation using Landsat ETM+ images, while ANN turns out to be more sensitive to the confusion between dry soils and bright impervious surfaces, and between shade and dark impervious surfaces. For ENVISAR ASAR images, ANN gets a better result with higher accuracy, while the SVM classifier produces more noise and has some edge effects.

Zhang, Hongsheng; Zhang, Yuanzhi; Lin, Hui

2012-08-01

7

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

Science.gov (United States)

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% only 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

2014-05-01

8

Contribution of impervious surfaces to urban evaporation  

Science.gov (United States)

Observational data and the Princeton urban canopy model, with its detailed representation of urban heterogeneity and hydrological processes, are combined to study evaporation and turbulent water vapor transport over urban areas. The analyses focus on periods before and after precipitation events, at two sites in the Northeastern United States. Our results indicate that while evaporation from concrete pavements, building rooftops, and asphalt surfaces is discontinuous and intermittent, overall these surfaces accounted for nearly 18% of total latent heat fluxes (LE) during a relatively wet 10 day period. More importantly, these evaporative fluxes have a significant impact on the urban surface energy balance, particularly during the 48 h following a rain event when impervious evaporation is the highest. Thus, their accurate representation in urban models is critical. Impervious evaporation after rainfall is also shown to correlate the sources of heat and water at the earth surface, resulting in a conditional scalar transport similarity over urban terrain following rain events.

Ramamurthy, P.; Bou-Zeid, E.

2014-04-01

9

Impacts of the impervious surfaces on the water use by urban trees: Hydrogen isotope analysis  

Science.gov (United States)

As the urban area is expanding and the populations of cities are growing, the role of urban trees in regulating biogeochemical cycles in urban regions is becoming more important. In particular, impervious surfaces in urban regions greatly disturb water use by trees. Here, we investigate the impacts of the anthropogenic structures on the water use pattern of trees on the Seoul National University campus. We select two types of gingko (Ginko biola L.) : one has been stabilized surrounded by impervious blocks and the other has been grown in natural conditions. To track the source of tree water use, xylem water at stem and soil water at 0-10, 40-50 90-100-cm depth are collected before and after precipitation for all trees. Precipitation is collected just after the rainfall event. Hydrogen isotope ratios of precipitation, soil water and xylem are analyzed to attribute source in tree water use. Finally we discuss the effects of impervious surfaces on root development and water use efficiencies.

Jeong, J.; Ryu, Y.

2013-12-01

10

Effect and relevance of the artificial drainage system when assessing the hydrologic impact of the imperviousness distribution within the watershed  

Science.gov (United States)

Cities and urban growth have relevant environmental and social impacts, which could eventually be enhanced or reduced during the urban planning process. From the point of view of hydrology, impermeability and natural soil compaction are one of the main problems that urbanization brings to watershed. Previous studies demonstrate and quantify the impacts of the distribution of imperviousness in a watershed, both on runoff volumes and flow, and the quality and integrity of streams and receiving bodies. Moreover, some studies have investigated the optimal distribution of imperviousness, based on simulating different scenarios of land use change and its effects on runoff, mostly at the outlet of the watershed. However, these studies typically do not address the impact of artificial drainage system associated with the imperviousness scenarios, despite it is known that storm sewer coverage affects the flow accumulation and generation of flow hydrographs. This study seeks to quantify the effects and relevance of the artificial system when it comes to assess the hydrological impacts of the spatial distribution of imperviousness and to determine the characteristics of this influence. For this purpose, an existing model to generate imperviousness distribution scenarios is coupled with a model developed to automatically generate artificial drainage networks. These models are applied to a natural watershed to generate a variety of imperviousness and storm sewer layout scenarios, which are evaluate with a morphoclimatic instantaneous unit hydrograph model. We first tested the ability of this approach to represent the joint effects of imperviousness (i.e. level and distribution) and storm sewer coverage. We then quantified the effects of these variables on the hydrological response, considering also different return period in order to take into account the variability of the precipitation regime. Overall, we show that the layout and spatial coverage of the storm sewer system affect the hydrologic response, and that these effects depend on the degree of imperviousness and the characteristics of the precipitation. Results of this research improve our understanding on how urban planning decisions can contribute to minimize the hydrologic and environmental impacts of urban development.

Thenoux, M.; Gironas, J. A.; Mejia, A.

2013-12-01

11

Determination effects of impervious areas on urban watershed.  

Science.gov (United States)

After the industrial revolution, urban growth has been increasing, especially with technological advances. Urbanization is accelerating environmental pollution and also affects climate significantly because of land use or land cover changes. In this study, the Hydrological Simulation Program-Fortran (HSPF) model developed by the United States Environment Protection Agency (USEPA) is used for modeling the impervious areas of Eski?ehir which is located in the Porsuk Stream Watershed in Inner Anatolia, Turkey. Effects of impervious areas of Eskisehir on the Porsuk Stream pollution between 1975 and 2010 have been investigated. Important water quality parameters like nitrate, orthophosphate, sediment, chloride, and total coliform are modeled. Impervious land segments have been found to be affecting all parameter concentrations and also surface flows significantly as determined using the t test with a confidence level of 95 %. PMID:25182427

?im?ek Uygun, Burcu; Albek, Mine

2015-02-01

12

Detection of impervious surface change with multitemporal Landsat images in an urban-rural frontier.  

Science.gov (United States)

Mapping and monitoring impervious surface dynamic change in a complex urban-rural frontier with medium or coarse spatial resolution images is a challenge due to the mixed pixel problem and the spectral confusion between impervious surfaces and other non-vegetation land covers. This research selected Lucas do Rio Verde County in Mato Grosso State, Brazil as a case study to improve impervious surface estimation performance by the integrated use of Landsat and QuickBird images and to monitor impervious surface change by analyzing the normalized multitemporal Landsat-derived fractional impervious surfaces. This research demonstrates the importance of two step calibrations. The first step is to calibrate the Landsat-derived fraction impervious surface values through the established regression model based on the QuickBird-derived impervious surface image in 2008. The second step is to conduct the normalization between the calibrated 2008 impervious surface image with other dates of impervious surface images. This research indicates that the per-pixel based method overestimates the impervious surface area in the urban-rural frontier by 50-60%. In order to accurately estimate impervious surface area, it is necessary to map the fractional impervious surface image and further calibrate the estimates with high spatial resolution images. Also normalization of the multitemporal fractional impervious surface images is needed to reduce the impacts from different environmental conditions, in order to effectively detect the impervious surface dynamic change in a complex urban-rural frontier. The procedure developed in this paper for mapping and monitoring impervious surface area is especially valuable in urban-rural frontiers where multitemporal Landsat images are difficult to be used for accurately extracting impervious surface features based on traditional per-pixel based classification methods as they cannot effectively handle the mixed pixel problem. PMID:21552379

Lu, Dengsheng; Moran, Emilio; Hetrick, Scott

2011-05-01

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Effect of Riparian Impervious Cover on Leaf Litter Decomposition Rates and Lotic Benthic Macroinvertebrate Diversity  

Science.gov (United States)

Riparian impervious cover has been implicated in reducing benthic biodiversity. We examined the impact of impervious cover on the decomposition and colonization of leafpacks in 6 sites located on three streams. The six sites ranged in impervious cover, in the drainage basin from 98% upstream at Meeting of the Waters Creek to 25% upstream on Bolin Creek. 5g leafpacks of dogwood leaves (Cornus florida), were placed at each site on October 15, 2004 and 5 replicates per site were collected on Oct. 25, Nov. 8 and Nov. 22. Decomposition rates were highest (AFDM remaining lowest) where forested cover was greatest, and lowest where impervious cover was greatest. The diversity of the initial macroinvertebrate colonization was highest with least impervious cover, and was dominated by chironomids where impervious cover was greatest. The negative impact of increasing impervious cover on stream community diversity is supported by this study. The ecosystem level process of leaf litter decomposition is also negatively affected.

Reice, S. R.; Rognstad, R. L.

2005-05-01

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Detection of impervious surface change with multitemporal Landsat images in an urban-rural frontier  

OpenAIRE

Mapping and monitoring impervious surface dynamic change in a complex urban-rural frontier with medium or coarse spatial resolution images is a challenge due to the mixed pixel problem and the spectral confusion between impervious surfaces and other non-vegetation land covers. This research selected Lucas do Rio Verde County in Mato Grosso State, Brazil as a case study to improve impervious surface estimation performance by the integrated use of Landsat and QuickBird images and to monitor imp...

Lu, Dengsheng; Moran, Emilio; Hetrick, Scott

2011-01-01

15

Global Distribution and Density of Constructed Impervious Surfaces  

Energy Technology Data Exchange (ETDEWEB)

We present the first global inventory of the spatial distribution and density of constructed impervious surface area (ISA). Examples of ISA include roads, parking lots, buildings, driveways, sidewalks and other manmade surfaces. While high spatial resolution is required to observe these features, the product we made is at one km2 resolution and is based on two coarse resolution indicators of ISA. Inputs into the product include the brightness of satellite observed nighttime lights and population count. The reference data used in the calibration were derived from 30 meter resolution ISA estimates of the USA from the U.S. Geological Survey. Nominally the product is for the years 2000-01 since both the nighttime lights and reference data are from those two years. We found that 1.05% of the United States land area is impervious surface (83,337 km2) and 0.43 % of the world's land surface (579,703 km2) is constructed impervious surface. China has more ISA than any other country (87,182 km2), but has only 67 m2 of ISA per person, compared to 297 m2 per person in the USA. Hyrdologic and environmental impacts of ISA begin to be exhibited when the density of ISA reaches 10% of the land surface. An examination of the areas with 10% or more ISA in watersheds finds that with the exception of Europe, the majority of watershed areas have less than 0.4% of their area at or above the 10% ISA threshold. The authors believe the next step for improving the product is to include reference ISA data from many more areas around the world.

Elvidge, Christopher D. [NOAA National Geophysical Data Center,; Tuttle, Benjamin T. [NOAA National Geophysical Data Center,; Sutton, Paul S. [University of Denver; Baugh, Kimberly E. [NOAA National Geophysical Data Center,; Howard, Ara T. [NOAA National Geophysical Data Center,; Milesi, Christina [Foundation of California State University, Monterey Bay, California.; Bhaduri, Budhendra L [ORNL; Nemani, Ramakrishna R [NASA Ames Research Center

2007-01-01

16

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

Directory of Open Access Journals (Sweden)

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

17

Procedure to detect impervious surfaces using satellite images and light detection and ranging (lidar) data  

Science.gov (United States)

The detection of impervious surfaces is an important issue in the study of urban and rural environments. Imperviousness refers to water's inability to pass through a surface. Although impervious surfaces represent a small percentage of the Earth's surface, knowledge of their locations is relevant to planning and managing human activities. Impervious structures are primarily manmade (e.g., roads and rooftops). Impervious surfaces are an environmental concern because many processes that modify the normal function of land, air, and water resources are initiated during their construction. This paper presents a novel method of identifying impervious surfaces using satellite images and light detection and ranging (LIDAR) data. The inputs for the procedure are SPOT images formed by four spectral bands (corresponding to red, green, near-infrared and mid-infrared wavelengths), a digital terrain model, and an .las file. The proposed method computes five decision indexes from the input data to classify the studied area into two categories: impervious (subdivided into buildings and roads) and non-impervious surfaces. The impervious class is divided into two subclasses because the elements forming this category (mainly roads and rooftops) have different spectral and height properties, and it is difficult to combine these elements into one group. The classification is conducted using a decision tree procedure. For every decision index, a threshold is set for which every surface is considered impervious or non-impervious. The proposed method has been applied to four different regions located in the north, center, and south of Spain, providing satisfactory results for every dataset.

Rodríguez-Cuenca, B.; Alonso-Rodríguez, M. C.; Domenech-Tofiño, E.; Valcárcel Sanz, N.; Delgado-Hernández, J.; Peces-Morera, Juan José; Arozarena-Villar, Antonio

2014-10-01

18

A tetrahedron-based endmember selection approach for urban impervious surface mapping.  

Science.gov (United States)

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

19

Rationale for the use of protective gaskets made of geotextiles and permeability evaluation of impervious coatings made of geomembranes  

Directory of Open Access Journals (Sweden)

Full Text Available The purpose of this paper is to design rationale for the use of protective pads of geotextiles and geomembranes permeability of PD using these pads. In order to justify the use of protective pads made of geotextile for reducing the defectiveness geomembrane soil fractions, the existing formulas to determine the thickness of the film element of impervious devices were examined. The calculations according to the formulas show that HDPE geomembrane with a minimum thickness of 1,0 mm, the protective lining of the geotextile should be applied at the average diameter fractions of soil of more than 6,5 mm, and for geomembranes HDPE - at a diameter of soil fractions of over 15,5 mm. In order to estimate the permeability of the TFG geomembrane using additional protective linings of geotextile in the scientific article the basic design schemes of such coatings with one and two layers of protective linings of geotextiles were considered. The evaluation results of water permeability of impervious surfaces with geotextile and for comparison - without geotextiles are given in a table. As it is shown by the data presented for the design scheme with a single layer of geotextile geomembrane at the base (in the presence of small holes in the geomembrane the decrease the effectiveness of an anti-covering is more than 268,0 %, and for the settlement scheme covering with two layers of geotextile there will be a very large reduction in the efficiency, which almost completely reduces the effectiveness of the coating to the value of the geomembrane permeability of a soil layer without geomembrane with the filtration flow rate of 71,75 m /day, against water permeability of the geomembrane cover - 38,52 m /day. From the foregoing, it can be concluded that the application of a coating design of well filtering gaskets made of geotextile is justified in terms of protecting the geomembrane from mechanical damage, but greatly reduces the effectiveness of impervious cover in case of its damage.

Kosichenko Yuriy Mikhaylovich

2015-03-01

20

An Integrated Method for Mapping Impervious and Pervious Areas in Urban Environments Using Hyperspectral and LiDAR Data  

Science.gov (United States)

As urbanization continues to increase and extreme climatic events become more prevalent, urban planners and engineers are actively implementing adaptive measures to protect urban assets and communities. To support the urban planning adaptation process, mapping of impervious and pervious areas is essential to understanding the hydrodynamic environment within urban areas for flood risk planning. The application of advance geospatial data and analytical techniques using remote sensing and GIS can improve land surface characterization to better quantify surface run-off and infiltration. This study presents a method to combine airborne hyperspectral and LiDAR data for classifying pervious (e.g. vegetation, gravel, and soil) and impervious (e.g. asphalt and concrete) areas within road allowance areas for the City of Surrey, British Columbia, Canada. Hyperspectral data was acquired using the Compact Airborne Spectrographic Imager (CASI) at 1 m ground spatial resolution, consisting of 72 spectral bands, and LiDAR data acquired from Leica Airborne LiDAR system at a density of 20 points/m2. A spectral library was established using 10 cm orthophotography and GIS data to identify surface features. In addition to spectral functions such as mean and standard deviation, several spectral indices were developed to discriminate between asphalt, concrete, gravel, vegetation, and shadows respectively. A spectral analysis of selected endmembers was conducted and an initial classification technique was applied using Spectral Angle Mapper (SAM). The classification results (i.e. shadows) were improved by integrating LIDAR data with the hyperspectral data.

Hashemi Beni, L.; McArdle, S.; Khayer, Y.

2014-11-01

21

Ecohydrology in semiarid urban ecosystems: Modeling the relationship between connected impervious area and ecosystem productivity  

Science.gov (United States)

In water-stressed, semiarid urban environments, connections between impervious surfaces and drainage networks may strongly impact the water use and ecosystem productivity of neighboring vegetated areas. We use an ecohydrologic model, the Regional Hydro-Ecological Simulation System (RHESSys), to quantify the sensitivity of vegetation water use and net primary productivity (NPP) to fine-scale impervious surface connectivity. We develop a set of very fine-scale (2 m2) scenarios that vary both the percentage of impervious surface and fraction of this impervious surface with direct hydrologic connections to urban drainage systems for a small hillslope. When driven by Mediterranean climate forcing, model estimates suggest that total vegetation water use declines with increasing impervious area. However, when impervious area is hydrologically disconnected from the urban drainage network, declines in water and carbon fluxes with decreased vegetated area can be partially, or in some cases even completely, offset by increased transpiration and NPP in the remaining vegetation. Relative increases in water use and NPP of remaining vegetation are much greater for deeply rooted shrubs and trees and negligible for shallow rooted grasses. We extrapolate our findings to the catchment scale by developing a first-order approximation of fine-scale impervious connection impacts on aggregate watershed water and carbon flux estimates. Our approach offers a computationally and data-efficient method for estimating the impact of impervious area connectivity on these ecohydrologic fluxes. For our only partially urbanized Santa Barbara watershed, estimates of water use and NPP that account for fine-scale impervious connection differed by more than 10% from those that did not.

Shields, Catherine; Tague, Christina

2015-01-01

22

Two-stage subpixel impervious surface coverage estimation: comparing classification and regression trees and artificial neural networks  

Science.gov (United States)

The paper presents accuracy comparison of subpixel classification based on medium resolution Landsat images, performed using machine learning algorithms built on decision and regression trees method (C.5.0/Cubist and Random Forest) and artificial neural networks. The aim of the study was to obtain the pattern of percentage impervious surface coverage, valid for the period of 2009-2010. Imperviousness index map generation was a two-stage procedure. The first step was classification, which divided the study area into categories: i) completely permeable (imperviousness index less than 1%) and ii) fully or partially impervious areas. For pixels classified as impervious, the percentage of impervious surface coverage in pixel area was estimated. The root mean square errors (RMS) of determination of the percentage of the impervious surfaces within a single pixel were 11.0% for C.5.0/Cubist method, 11.3% for Random Forest method and 12.6% using artificial neural networks. The introduction of the initial hard classification into completely permeable areas (with imperviousness index <1%) and impervious areas, allowed to improve the accuracy of imperviousness index estimation on poorly urbanized areas covering large areas of the Dobczyce Reservoir catchment. The effect is also visible on final imperviousness index maps.

Bernat, Katarzyna; Drzewiecki, Wojciech

2014-10-01

23

Improving Distributed Runoff Prediction in Urbanized Catchments with Remote Sensing based Estimates of Impervious Surface Cover  

OpenAIRE

The amount and intensity of runoff on catchment scale are strongly determined by the presence of impervious land-cover types, which are the predominant cover types in urbanized areas. This paper examines the impact of different methods for estimating impervious surface cover on the prediction of peak discharges, as determined by a fully distributed rainfall-runoff model (WetSpa), for the upper part of the Woluwe River catchment in the southeastern part of Brussels. The study shows that detail...

Frank Canters; Okke Batelaan; Tim De Roeck; Tim Van de Voorde; Jaroslaw Chormanski

2008-01-01

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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

25

Impervious Surface Assessment of the Towne Creek Watershed, Etowah County, Alabama  

Science.gov (United States)

A Geographic Information System (GIS) based approach was used to do a preliminary assessment of a watershed's vulnerability and has been proven to be a quick, inexpensive, and effective means to provide guidance to the watershed manager. This GIS-based approach was used in an assessment of a watershed's proportion of impervious surface as a quantifiable measurement its vulnerability. The percent of a watershed area that is impervious was determined by utilizing the Impervious Surface Analysis Tool (ISAT), which is an extension of the ArcGIS program. ISAT uses landuse/landcover, watershed boundary, and population density data sets to calculate the percent impervious surface (%IS). The Towne Creek watershed covers 24,730 acres in southern Etowah County, Alabama, was investigated. The watershed, which empties into the Middle Coosa River, includes the suburbs of the City of Gadsden. The watershed was delineated into 75 catchments ranging from 230 to 3,163 acres. Initial assessment of the watershed estimated 10.5% of the area is impervious. Individual catchments within the watershed were then classified as being degraded (>25 %IS), impaired (10 to 25 %IS) or protected (<10 %IS). According to this classification scheme, 5 catchments covering 2.6% of the watershed is classified as being degraded, and 5 catchments covering 3.6% of the watershed is impaired, and the remaining 65 catchments covering 93.8% of the watershed is protected.

Steffy, D. A.; Blalock, C.

2004-12-01

26

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

27

Mapping Impervious Surfaces Globally at 30m Resolution Using Landsat Global Land Survey Data  

Science.gov (United States)

Impervious surfaces, mainly artificial structures and roads, cover less than 1% of the world's land surface (1.3% over USA). Regardless of the relatively small coverage, impervious surfaces have a significant impact on the environment. They are the main source of the urban heat island effect, and affect not only the energy balance, but also hydrology and carbon cycling, and both land and aquatic ecosystem services. In the last several decades, the pace of converting natural land surface to impervious surfaces has increased. Quantitatively monitoring the growth of impervious surface expansion and associated urbanization has become a priority topic across both the physical and social sciences. The recent availability of consistent, global scale data sets at 30m resolution such as the Global Land Survey from the Landsat satellites provides an unprecedented opportunity to map global impervious cover and urbanization at this resolution for the first time, with unprecedented detail and accuracy. Moreover, the spatial resolution of Landsat is absolutely essential to accurately resolve urban targets such a buildings, roads and parking lots. With long term GLS data now available for the 1975, 1990, 2000, 2005 and 2010 time periods, the land cover/use changes due to urbanization can now be quantified at this spatial scale as well. In the Global Land Survey - Imperviousness Mapping Project (GLS-IMP), we are producing the first global 30 m spatial resolution impervious cover data set. We have processed the GLS 2010 data set to surface reflectance (8500+ TM and ETM+ scenes) and are using a supervised classification method using a regression tree to produce continental scale impervious cover data sets. A very large set of accurate training samples is the key to the supervised classifications and is being derived through the interpretation of high spatial resolution (~2 m or less) commercial satellite data (Quickbird and Worldview2) available to us through the unclassified archive of the National Geospatial Intelligence Agency (NGA). For each continental area several million training pixels are derived by analysts using image segmentation algorithms and tools and then aggregated to the 30m resolution of Landsat. Here we will discuss the production/testing of this massive data set for Europe, North and South America and Africa, including assessments of the 2010 surface reflectance data. This type of analysis is only possible because of the availability of long term 30m data sets from GLS and shows much promise for integration of Landsat 8 data in the future.

Brown de Colstoun, E.; Huang, C.; Wolfe, R. E.; Tan, B.; Tilton, J.; Smith, S.; Phillips, J.; Wang, P.; Ling, P.; Zhan, J.; Xu, X.; Taylor, M. P.

2013-12-01

28

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...

29

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

30

Impacts of impervious cover, water withdrawals, and climate change on river flows in the conterminous US  

Directory of Open Access Journals (Sweden)

Full Text Available Rivers are essential to aquatic ecosystem and societal sustainability, but are increasingly impacted by water withdrawals, land-use change, and climate change. The relative and cumulative effects of these stressors on continental river flows are relatively unknown. In this study, we used an integrated water balance and flow routing model to evaluate the impacts of impervious cover and water withdrawal on river flow across the conterminous US at the 8-digit Hydrologic Unit Code (HUC watershed scale. We then estimated the impacts of projected change in withdrawals, impervious cover, and climate under the B1 "Low" and A2 "High" emission scenarios on river flows by 2060. Our results suggest that compared to no impervious cover, 2010 levels of impervious cover increased river flows by 9.9% on average with larger impacts in and downstream of major metropolitan areas. In contrast, compared to no water withdrawals, 2005 withdrawals decreased river flows by 1.4% on average with larger impacts in heavily irrigated arid regions of Western US. By 2060, impacts of climate change were predicted to overwhelm the potential gain in river flow due to future changes in impervious cover and add to the potential reduction in river flows from withdrawals, decreasing mean annual river flows from 2010 levels by 16% on average. However, increases in impervious cover by 2060 may offset the impact of climate change during the growing season in some watersheds. Large water withdrawals will aggravate the predicted impact of climate change on river flows, particularly in the Western US. Predicted ecohydrological impacts of land cover, water withdrawal, and climate change will likely include alteration of the terrestrial water balance, stream channel habitat, riparian and aquatic community structure in snow-dominated basins, and fish and mussel extirpations in heavily impacted watersheds. These changes may also require new infrastructure to support increasing anthropogenic demand for water, relocation of agricultural production, and/or water conservation measures. Given that the impacts of land use, withdrawals and climate may be either additive or offsetting in different magnitudes, integrated and spatially explicit modeling and management approaches are necessary to effectively manage water resources for aquatic life and human use in the face of global change.

P. V. Caldwell

2012-08-01

31

Monitoring urban impervious surface area change using China-Brazil Earth Resources Satellites and HJ-1 remote sensing images  

Science.gov (United States)

Impervious surface area (ISA) plays an important role in monitoring urbanization and related environmental changes, and has become a hotspot in urban and environmental studies. Xuzhou City, located in northwest Jiangsu Province, China, is chosen as the study area, and two scenes of China-Brazil Earth Resources Satellites images and one scene of HJ-1 image are employed to estimate ISA percentage and analyze the change trend from 2001 to 2009. Using a linear spectral mixture model (LSMM) and nonlinear backpropagation neural network (BPNN) method, all pixels are decomposed to derive four fraction images representing the abundance of four endmembers: vegetation, high-albedo objects, low-albedo objects, and soil. The ISA percentage is then derived by the combination of high- and low-albedo fraction images after removing the influence of water. Some high spatial resolution images are selected to validate the ISA estimation results, and the experimental results indicate that the accuracy of BPNN is higher than LSMM. By comparing the urban ISA abundances derived by BPNN from three dates, it is found that the ISA of Xuzhou City has increased rapidly from 2001 to 2009, especially in the northeast and southeast regions, corresponding to the urban planning scheme and fast urbanization. Compared to other medium remote sensing images, the revisit cycle of HJ-1 multispectral image is only two days, demonstrating the potential of such data for ISA extraction in urbanization, disaster, and other related applications.

Du, Peijun; Xia, Junshi; Feng, Li

2015-01-01

32

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 (urban stormwater runoff, as represented by EI, drives geomorphic 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

33

Cutaneous Heat Loss with Three Surgical Drapes, One Impervious to Moisture  

OpenAIRE

A new surgical drape, which is impervious to moisture, presumably reduces evaporative heat loss. We compared cutaneous heat loss and skin temperature in volunteers covered with this drape to two conventional surgical drapes (Large Surgical Drape and Medline Proxima). With IRB approval and informed consent, we calculated cutaneous heat loss and skin-surface temperatures from 15 area-weighted thermal flux transducers in 8 volunteers. In random order, each of the drapes was evaluated with dry tr...

Maglinger, Paul E.; Sessler, Daniel I.; Lenhardt, Rainer

2005-01-01

34

Contribution of directly connected and isolated impervious areas to urban drainage network hydrographs  

Directory of Open Access Journals (Sweden)

Full Text Available This paper addresses the mass balance error observed in runoff hydrographs in urban watersheds by introducing assumptions regarding the contribution of infiltrated rainfall from pervious areas and isolated impervious area (IIA to the runoff hydrograph. Rainfall infiltrating into pervious areas has been assumed not to contribute to the runoff hydrograph until Hortonian excess rainfall occurs. However, mass balance analysis in an urban watershed indicates that rainfall infiltrated to pervious areas can contribute directly to the runoff hydrograph, thereby offering an explanation for the long hydrograph tail commonly observed in runoff from urban storm sewers. In this study, a hydrologic analysis based on the width function is introduced, with two types of width functions obtained from both pervious and impervious areas, respectively. The width function can be regarded as the direct interpretation of the network response. These two width functions are derived to obtain distinct response functions for directly connected impervious areas (DCIA, IIA, and pervious areas. The results show significant improvement in the estimation of runoff hydrographs and suggest the need to consider the flow contribution from pervious areas to the runoff hydrograph. It also implies that additional contribution from flow paths through joints and cracks in sewer pipes needs to be taken into account to improve the estimation of runoff hydrographs in urban catchments.

Y. Seo

2013-09-01

35

Contribution of directly connected and isolated impervious areas to urban drainage network hydrographs  

Science.gov (United States)

This paper addresses the mass balance error observed in runoff hydrographs in urban watersheds by introducing assumptions regarding the contribution of infiltrated rainfall from pervious areas and isolated impervious area (IIA) to the runoff hydrograph. Rainfall infiltrating into pervious areas has been assumed not to contribute to the runoff hydrograph until Hortonian excess rainfall occurs. However, mass balance analysis in an urban watershed indicates that rainfall infiltrated to pervious areas can contribute directly to the runoff hydrograph, thereby offering an explanation for the long hydrograph tail commonly observed in runoff from urban storm sewers. In this study, a hydrologic analysis based on the width function is introduced, with two types of width functions obtained from both pervious and impervious areas, respectively. The width function can be regarded as the direct interpretation of the network response. These two width functions are derived to obtain distinct response functions for directly connected impervious areas (DCIA), IIA, and pervious areas. The results show significant improvement in the estimation of runoff hydrographs and suggest the need to consider the flow contribution from pervious areas to the runoff hydrograph. It also implies that additional contribution from flow paths through joints and cracks in sewer pipes needs to be taken into account to improve the estimation of runoff hydrographs in urban catchments.

Seo, Y.; Choi, N.-J.; Schmidt, A. R.

2013-09-01

36

Contribution of directly connected and isolated impervious areas to urban drainage network hydrographs  

Directory of Open Access Journals (Sweden)

Full Text Available This paper addresses the mass balance error observed in runoff hydrographs in urban watersheds by introducing assumptions regarding the contribution of infiltrated rainfall from pervious areas and isolated impervious area (IIA to the runoff hydrograph. Rainfall infiltrating into pervious areas has been assumed not to contribute to the runoff hydrograph until Hortonian excess rainfall occurs. However, mass balance analysis in an urban watershed indicates that rainfall infiltrated to pervious areas can contribute to direct runoff hydrograph, thereby offering an explanation for the long hydrograph tail commonly observed in runoff from urban storm sewers. In this study, a hydrologic analysis based on the width function is introduced, with two types of width functions obtained from both pervious and impervious areas, respectively. The width function can be regarded as the direct interpretation of the network response. These two width functions are derived to obtain distinct response functions for directly connected impervious areas (DCIA, IIA, and pervious areas. The results show significant improvement in the estimation of runoff hydrographs and suggest the need to consider the flow contribution from pervious areas to the runoff hydrograph. It also implies that additional contribution from flow paths through joints and cracks in sewer pipes needs to be taken into account to improve the estimation of runoff hydrographs in urban catchments.

Y. Seo

2013-05-01

37

Quantifying sub-pixel urban impervious surface through fusion of optical and inSAR imagery  

Science.gov (United States)

In this study, we explored the potential to improve urban impervious surface modeling and mapping with the synergistic use of optical and Interferometric Synthetic Aperture Radar (InSAR) imagery. We used a Classification and Regression Tree (CART)-based approach to test the feasibility and accuracy of quantifying Impervious Surface Percentage (ISP) using four spectral bands of SPOT 5 high-resolution geometric (HRG) imagery and three parameters derived from the European Remote Sensing (ERS)-2 Single Look Complex (SLC) SAR image pair. Validated by an independent ISP reference dataset derived from the 33 cm-resolution digital aerial photographs, results show that the addition of InSAR data reduced the ISP modeling error rate from 15.5% to 12.9% and increased the correlation coefficient from 0.71 to 0.77. Spatially, the improvement is especially noted in areas of vacant land and bare ground, which were incorrectly mapped as urban impervious surfaces when using the optical remote sensing data. In addition, the accuracy of ISP prediction using InSAR images alone is only marginally less than that obtained by using SPOT imagery. The finding indicates the potential of using InSAR data for frequent monitoring of urban settings located in cloud-prone areas. Copyright ?? 2009 by Bellwether Publishing, Ltd. All right reserved.

Yang, L.; Jiang, L.; Lin, H.; Liao, M.

2009-01-01

38

High-quality observation of surface imperviousness for urban runoff modelling using UAV imagery  

Science.gov (United States)

Modelling rainfall-runoff in urban areas is increasingly applied to support flood risk assessment particularly against the background of a changing climate and an increasing urbanization. These models typically rely on high-quality data for rainfall and surface characteristics of the area. While recent research in urban drainage has been focusing on providing spatially detailed rainfall data, the technological advances in remote sensing that ease the acquisition of detailed land-use information are less prominently discussed within the community. The relevance of such methods increase as in many parts of the globe, accurate land-use information is generally lacking, because detailed image data is unavailable. Modern unmanned air vehicles (UAVs) allow acquiring high-resolution images on a local level at comparably lower cost, performing on-demand repetitive measurements, and obtaining a degree of detail tailored for the purpose of the study. In this study, we investigate for the first time the possibility to derive high-resolution imperviousness maps for urban areas from UAV imagery and to use this information as input for urban drainage models. To do so, an automatic processing pipeline with a modern classification method is tested and applied in a state-of-the-art urban drainage modelling exercise. In a real-life case study in the area of Lucerne, Switzerland, we compare imperviousness maps generated from a consumer micro-UAV and standard large-format aerial images acquired by the Swiss national mapping agency (swisstopo). After assessing their correctness, we perform an end-to-end comparison, in which they are used as an input for an urban drainage model. Then, we evaluate the influence which different image data sources and their processing methods have on hydrological and hydraulic model performance. We analyze the surface runoff of the 307 individual subcatchments regarding relevant attributes, such as peak runoff and volume. Finally, we evaluate the model's channel flow prediction performance through a cross-comparison with reference flow measured at the catchment outlet. We show that imperviousness maps generated using UAV imagery processed with modern classification methods achieve accuracy comparable with standard, off-the-shelf aerial imagery. In the examined case study, we find that the different imperviousness maps only have a limited influence on modelled surface runoff and pipe flows. We conclude that UAV imagery represents a valuable alternative data source for urban drainage model applications due to the possibility to flexibly acquire up-to-date aerial images at a superior quality and a competitive price. Our analyses furthermore suggest that spatially more detailed urban drainage models can even better benefit from the full detail of UAV imagery.

Tokarczyk, P.; Leitao, J. P.; Rieckermann, J.; Schindler, K.; Blumensaat, F.

2015-01-01

39

Synergistic use of optical and InSAR data for urban impervious surface mapping: A case study in Hong Kong  

Science.gov (United States)

A wide range of urban ecosystem studies, including urban hydrology, urban climate, land use planning and watershed resource management, require accurate and up-to-date geospatial data of urban impervious surfaces. In this study, the potential of the synergistic use of optical and InSAR data in urban impervious surface mapping at the sub-pixel level was investigated. A case study in Hong Kong was conducted for this purpose by applying a classification and regression tree (CART) algorithm to SPOT 5 multispectral imagery and ERS-2 SAR data. Validated by reference data derived from high-resolution colour-infrared (CIR) aerial photographs, our results show that the addition of InSAR feature information can improve the estimation of impervious surface percentage (ISP) in comparison with using SPOT imagery alone. The improvement is especially notable in separating urban impervious surface from the vacant land/bare ground, which has been a difficult task in ISP modelling with optical remote sensing data. In addition, the results demonstrate the potential to map urban impervious surface by using InSAR data alone. This allows frequent monitoring of world's cities located in cloud-prone and rainy areas. ?? 2009 Taylor & Francis.

Jiang, L.; Liao, M.; Lin, H.; Yang, L.

2009-01-01

40

Effects of impervious cover on the surface water quality and aquatic ecosystem of the Kyeongan stream in South Korea.  

Science.gov (United States)

The extent of impervious cover in a watershed has been linked to the quality of an urban aquatic environment. The Kyeongan watershed in South Korea was investigated to evaluate the relationship between the total impervious area (TIA) and the aquatic ecosystem of the watershed, including water quality and aquatic life using a relatively high-resolution (0.4 m) image. The TIA was found to be approximately 12% of the watershed, which indicates that the quality of its environment was being adversely affected by it. For water quality, Pearson correlation analyses showed that all water quality parameters studied were found to be positively correlated with TIA at p diatom index for organic pollution and trophic diatom index were found to be highly correlated with TIA, whereas physical habitat and benthic macroinvertebrates were poorly correlated with TIA. However, the results indicate that the extent of impervious cover can be a useful indicator for predicting the status of specific ecosystem of streams. PMID:22953448

Lee, Bum-Yeon; Park, Shin-Jeong; Paule, Ma Cristina; Jun, Woosong; Lee, Chang-Hee

2012-08-01

41

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

42

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

43

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.)

44

Downscaling of thermal images over urban areas using the land surface temperature-impervious percentage relationship  

Science.gov (United States)

Intensive expansion and densification of urban areas decreases environmental quality and quality of urban life as exemplified by the urban heat island effect. For this reason, thermal information is becoming an increasingly important data source for integration in urban studies. It is expected that future spaceborne thermal sensors will provide data at appropriate spatial and temporal resolutions for urban studies. Until they become operational, research has to rely on downscaling algorithms increasing the spatial resolution of relatively coarse resolution thermal images albeit having a high temporal resolution. Existing downscaling algorithms, however, have been developed for sharpening images over rural and natural areas, resulting in large errors when applied to urban areas. The objective of this study is to adapt the DisTrad method for downscaling land surface temperature (LST) over urban areas using the relationship between LST and impervious percentage. The proposed approach is evaluated by sharpening aggregated LST derived from Landsat 7 ETM+ imagery collected over the city of Dublin on May 24th 2001. The new approach shows improved downscaling results over urban areas for all evaluated resolutions, especially in an environment with mixed land cover. The adapted DisTrad approach was most successful at a resolution of 480 m, resulting in a correlation of R2 = 0.84 with an observed image at the same resolution. Furthermore, sharpening using the adapted DisTrad approach was able to preserve the spatial autocorrelation present in urban environments. The unmixing performance of the adapted DisTrad approach improves with decreasing resolution due to the fact that the functional relationship between LST and impervious percentage was defined at coarse resolutions.

Essa, W.; van der Kwast, J.; Verbeiren, B.; Batelaan, O.

2013-08-01

45

Road Detection from Remote Sensing Images using Impervious Surface Characteristics: Review and Implication  

Science.gov (United States)

The extraction of road network is an emerging area in information extraction from high-resolution satellite images (HRSI). It is also an interesting field that incorporates various tactics to achieve road network. The process of road detection from remote sensing images is quite complex, due to the presence of various noises. These noises could be the vehicles, crossing lines and toll bridges. Few small and large false road segments interrupt the extraction of road segments that happens due to the similar spectral behavior in heterogeneous objects. To achieve a better level of accuracy, numerous factors play their important role, such as spectral data of satellite sensor and the information related to land surface area. Therefore the interpretation varies on processing of images with different heuristic parameters. These parameters have tuned according to the road characteristics of the terrain in satellite images. There are several approaches proposed and implemented to extract the roads from HRSI comprising a single or hybrid method. This kind of hybrid approach has also improved the accuracy of road extraction in comparison to a single approach. Some characteristics related to impervious and non-impervious surfaces are used as salient features that help to improve the extraction of road area only in the correct manner. These characteristics also used to utilize the spatial, spectral and texture features to increase the accuracy of classified results. Therefore, aforesaid characteristics have been utilized in combination of road spectral properties to extract road network only with improved accuracy. This evaluated road network is quite accurate with the help of these defined methodologies.

Singh, P. P.; Garg, R. D.

2014-11-01

46

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

47

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

48

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.

49

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

OpenAIRE

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 ironp...

Akwasi Asamoah; Charles Antwi-Boasiako; Kwasi Frimpong-Mensah

2013-01-01

50

Using long time series of Landsat data to monitor impervious surface dynamics: a case study in the Zhoushan Islands  

Science.gov (United States)

Islands are an important part of the marine ecosystem. Increasing impervious surfaces in the Zhoushan Islands due to new development and increased population have an ecological impact on the runoff and water quality. Based on time-series classification and the complement of vegetation fraction in urban regions, Landsat thematic mapper and other high-resolution satellite images were applied to monitor the dynamics of impervious surface area (ISA) in the Zhoushan Islands from 1986 to 2011. Landsat-derived ISA results were validated by the high-resolution Worldview-2 and aerial photographs. The validation shows that mean relative errors of these ISA maps are expansion rate of 5.59 km2 per year. The major land conversions to high densities of ISA were from the tidal zone and arable lands. The expansions of ISA were unevenly distributed and most of them were located along the periphery of these islands. Time-series maps revealed that ISA expansions happened continuously over the last 25 years. Our analysis indicated that the policy and the topography were the dominant factors controlling the spatial patterns of ISA and its expansions in the Zhoushan Islands. With continuous urbanization processes, the rapid ISA expansions may not be stopped in the near feature.

Zhang, Xiaoping; Pan, Delu; Chen, Jianyu; Zhan, Yuanzeng; Mao, Zhihua

2013-01-01

51

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

52

Sensibilidad y regionalización del parámetro de impermeabilidad en una cuenca urbana / Sensitivity analysis and regional imperviousness in an urban basin  

Scientific Electronic Library Online (English)

Full Text Available SciELO Mexico | Language: Spanish Abstract in spanish La complejidad en la determinación inicial del parámetro hidrológico de impermeabilidad, comúnmente abreviado como (% imp.), se debe, entre otras razones, a la alta variabilidad espacial que caracteriza el medio urbano, en el cual se presentan varias coberturas de suelo en pequeñas porciones de terr [...] eno, que en ocasiones llegan a ser menores de una hectárea. Con este artículo se busca hacer una contribución metodológica para la estimación indirecta de tal parámetro, a partir de la cantidad de habitantes por unidad de área y de la relación domicilios por área, tomando como caso de estudio dos subcuencas localizadas dentro del sector oeste de la ciudad de Coro, Venezuela. Primero se realizaron pruebas de sensibilidad del parámetro y después se probó la técnica de interpretación digital automática de imágenes de satélite con clasificadores tradicionales para determinar su cuantificación, revelando incoherencias predominantes en las zonas de transición con usos mezclados. Se optó por la extracción manual de zonas impermeables y se construyeron curvas regionalizadas. Desde el punto de vista metodológico, el procedimiento resulta eficaz, ya que las curvas regionalizadas permiten ahorrar tiempo importante en la estimación inicial de este parámetro. Abstract in english The complexity of the initial determination of water imperviousness, commonly abbreviated as % imp., is partially due to the high spatial variability that characterizes an urban environment, which presents a variety of land covers within small portions of land, some of which may be less than 1 hecta [...] re. This article seeks to contribute to the methodology for indirectly measuring imperviousness based on the number of inhabitants and residences per unit area, using as a case study two sub-basins located in the western sector of the city of Coro, Venezuela. First, sensitivity tests of imperviousness were performed and then the technique for automatic digital interpretation of satellite images with traditional classifiers was tested to determine its quantification, revealing considerable inconsistencies in the transition zones with mixed uses. Manual extraction of impermeable zones was chosen and regionalized curves were constructed. From a methodological perspective, the procedure was effective since the regionalized curves enabled saving a significant amount of time in the initial calculation of this parameter.

Luis, Alejandro-Sánchez; Yoel, Martínez-González.

2013-03-01

53

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

54

Using environmental metrics to describe the spatial and temporal evolution of landscape structure and soil hydrology and fertility  

OpenAIRE

In this work a methodology using Geographical Information Systems was developed and applied to a temporal series of land cover layers (for the years 1956, 1978, 1991 and 2010) in the municipality of Vall d’Uxó, Eastern Spain. Four types of metrics were implemented (1) spatial representation of the degree of artificialisation, (2) patchiness and fragmentation, (3) fertility dynamics of soils according to their land capability, and (4) soils imperviousness and loss of water retention capacit...

Pascual Aguilar, Juan Antonio; Sanz Garci?a, Juana; Bustamante Gutie?rrez, Irene; Kallache, Malaak

2011-01-01

55

Imperviousness as a predictor for infestation levels of container-breeding mosquitoes in a focus of dengue and Saint Louis encephalitis in Argentina.  

Science.gov (United States)

Dengue and Saint Louis encephalitis virus are among the most important emerging viruses transmitted by mosquitoes at the global scale, and from 2009 onward both diseases have reached temperate Argentina. To test whether the urbanization level can be used as a predictor for the infestation levels of container-breeding mosquito vectors, we searched for Aedes aegypti and Culex pipiens in 8400 water-filled containers from 14 cemeteries of Buenos Aires Province and we used generalized linear models to relate positive containers with the impervious area quantified inside (internal PIA) and outside (external PIA) cemeteries. The best model for Ae. aegypti explained 91% of the variability and included the season, the internal PIA and the external PIA at 1km as a quadratic function, showing a parabolic response peaking in ?75%. Regarding the infestation levels of Cx. pipiens, the final model explained 75% of the variability and included only the season. In view of these results, the percentage of impervious area efficiently predicted the infestation levels of Ae. aegypti but not of Cx. pipiens. Considering the worldwide relevance of the former in dengue transmission, the simple quantification of imperviousness proposed herein provides a helpful basis for vector surveillance and control in urbanized areas. PMID:24071380

Rubio, A; Cardo, M V; Carbajo, A E; Vezzani, D

2013-12-01

56

The Integrated Use of DMSP-OLS Nighttime Light and MODIS Data for Monitoring Large-Scale Impervious Surface Dynamics: A Case Study in the Yangtze River Delta  

Directory of Open Access Journals (Sweden)

Full Text Available The timely and reliable estimation of imperviousness is essential for the scientific understanding of human-Earth interactions. Due to the unique capacity of capturing artificial light luminosity and long-term data records, the Defense Meteorological Satellite Program (DMSP’s Operational Line-scan System (OLS nighttime light (NTL imagery offers an appealing opportunity for continuously characterizing impervious surface area (ISA at regional and continental scales. Although different levels of success have been achieved, critical challenges still remain in the literature. ISA results generated by DMSP-OLS NTL alone suffer from limitations due to systemic defects of the sensor. Moreover, the majority of developed methodologies seldom consider spatial heterogeneity, which is a key issue in coarse imagery applications. In this study, we proposed a novel method for multi-temporal ISA estimation. This method is based on a linear regression model developed between the sub-pixel ISA fraction and a multi-source index with the integrated use of DMSP-OLS NTL and MODIS NDVI. In contrast with traditional regression analysis, we incorporated spatial information to the regression model for obtaining spatially adaptive coefficients at the per-pixel level. To produce multi-temporal ISA maps using a mono-temporal reference dataset, temporally stable samples were extracted for model training and validation. We tested the proposed method in the Yangtze River Delta and generated annual ISA fraction maps for the decade 2000–2009. According to our assessments, the proposed method exhibited substantial improvements compared with the standard linear regression model and provided a feasible way to monitor large-scale impervious surface dynamics.

Zhenfeng Shao

2014-09-01

57

Estimativa de área impermeabilizada diretamente conectada e sua utilização como coeficiente de escoamento superficial / Estimate of directly connected impervious areas and its use as runoff coefficient  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Neste estudo realizou-se a caracterização do uso e ocupação do solo na cidade de Ribeirão Preto (SP), além da análise detalhada da impermeabilização urbana e conectividade hidráulica dos lotes. Também foi avaliado o coeficiente de escoamento superficial (C) para seis sub-bacias, utilizando-se três m [...] étodos com diferentes níveis de precisão. Utilizando-se o Método Racional com os valores estimados de C, calcularam-se os picos de vazão para as sub-bacias. Identificou-se que a impermeabilização cresce com a redução da área do lote. As estimativas de C resultam em diferenças importantes em seus valores, refletindo na previsão da vazão. A utilização de tabelas com C detalhado e no seu limite superior se aproxima dos valores estimados por C AIDC. Recomenda-se estimar C AIDC a partir da área do lote ou pesquisa de campo. Abstract in english This paper presents a study of characterization of land occupation and its use in the city of Ribeirão Preto (São Paulo), as well as a detailed analysis of the urban imperviousness and hydraulic connectivity of the plots. The runoff coefficient (C) for siz sub-basins was evaluated on the basis of th [...] ree different definitions. The peaks of outflow for the sub-basins were calculated using the Rational Method with the estimated values of C. It was identified that the imperviousness increases as the area of the plot decreases. The estimative of the C show important differences in its values, influencing the outflow. The use of tables with detailed and maximal C values beyond its superior limitation is equivalent to the values estimated with C DCIA. It is recommended that the C DCIA relative to the area be estimated based on the plot or field researches.

Leonardo Monteiro, Garotti; Ademir Paceli, Barbassa.

2010-03-01

58

Toward a geoinformatics framework for understanding the social and biophysical influences on urban nutrient pollution due to residential impervious service connectivity  

Science.gov (United States)

Water sustainability has been recognized as a fundamental problem of science whose solution relies in part on high-performance computing. Stormwater management is a major concern of urban sustainability. Understanding interactions between urban landcover and stormwater nutrient pollution requires consideration of fine-scale residential stormwater management, which in turn requires high-resolution LIDAR and landcover data not provided through national spatial data infrastructure, as well as field observation at the household scale. The objectives of my research are twofold: (1) advance understanding of the relationship between residential stormwater management practices and the export of nutrient pollution from stormwater in urbanized ecosystems; and (2) improve the informatics workflows used in community ecohydrology modeling as applied to heterogeneous urbanized ecosystems. In support of these objectives, I present preliminary results from initial work to: (1) develop an ecohydrology workflow platform that automates data preparation while maintaining data provenance and model metadata to yield reproducible workflows and support model benchmarking; (2) perform field observation of existing patterns of residential rooftop impervious surface connectivity to stormwater networks; and (3) develop Regional Hydro-Ecological Simulation System (RHESSys) models for watersheds in Baltimore, MD (as part of the Baltimore Ecosystem Study (BES) NSF Long-Term Ecological Research (LTER) site) and Durham, NC (as part of the NSF Urban Long-Term Research Area (ULTRA) program); these models will be used to simulate nitrogen loading resulting from both baseline residential rooftop impervious connectivity and for disconnection scenarios (e.g. roof drainage to lawn v. engineered rain garden, upslope v. riparian). This research builds on work done as part of the NSF EarthCube Layered Architecture Concept Award where a RHESSys workflow is being implemented in an iRODS (integrated Rule-Oriented Data System) environment. Modeling the ecohydrology of urban ecosystems in a reliable and reproducible manner requires a flexible scientific workflow platform that allows rapid prototyping with large-scale spatial datasets and model refinement integrating expert knowledge with local datasets and household surveys.

Miles, B.; Band, L. E.

2012-12-01

59

Sticky windows: chemical and biological characteristics of the organic film derived from particulate and gas-phase air contaminants found on an urban impervious surface.  

Science.gov (United States)

A novel environmentally derived mixture that integrates exposure to atmospherically derived gas- and particle-phase compounds in urban areas-namely, the organic film that develops as a thin layer on urban impervious surfaces-was investigated for its ability to induce gene expression via the aryl hydrocarbon receptor (AhR). The organic film on window glass from 21 sites in downtown Toronto (Ontario, Canada) was found to contain a complex mixture of environmental contaminants typical of urban environments, notably PAHs, n-alkanes, PCBs, organochlorine (OC) pesticides, and polar constituents. Using a stably transfected reporter cell line, we found that the crude extract of organic film induces AhR-dependent gene expression in a dose-dependent fashion. Three subfractions of the crude extract induced significant luciferase expression: nonpolar aromatic > polar aromatic > nonpolar aliphatic. Recombination of the fractions did not lead to recovery of the full activity of the crude extract, which may indicate that some of the compounds lost during fractionation were significant contributors to the induction observed with the crude extract. The interactions between a tonic dose of B[ a]P (10(-7) M) and each of the aromatic fractions were determined to be antagonistic following analysis by the method of isoboles. Our results suggest that organic film makes up a diverse array of compounds active at the AhR and that these compounds may not interact in a strictly additive manner. PMID:12712271

Hodge, E M; Diamond, M L; McCarry, B E; Stern, G A; Harper, P A

2003-05-01

60

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

61

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

62

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.

Chris Fox

63

Gully Growth Patterns and Soil Loss under Rainfall at Urban Underground Drainage Construction Site, Uyo  

Directory of Open Access Journals (Sweden)

Full Text Available This study investigated, evaluated and modeled patterns of growth of gully morphometric dimension and soil loss volume under prevailing rainfall on the slopes of land graded for the construction of underground drainage at Uyo but delayed in completion. Land grading at underground (tunnel drainage construction site rendered the exposed surface very impervious but young ephemeral gullies developed due to delays in completion. Data on gully morphometric dimension, soil loss and depth of rainfall were analyzed using SPSS ver. 17 statistical package. Mean gully growth in length, width and depth were different at 2.54±0.86, 0.923±0.29 and 0.41±0.11 m, respectively, yielding 3.87±0.08 m2 as mean volume of soil loss at full stage. Cubic polynomial was best-fit model for growth in length (R2 = 79% and width (R2 = 69% using weekly rainfall for an annual season. All gully sites had constant depth change, better predicted by quadratic (R2 = 13% than linear (R2 = 9% functions. Mean volume of soil loss per unit rainfall amount varied with low, medium and high rainfall amount and was highest at slope bottom (33 cm3/cm and least at the crest (6.99 cm3/cm with R2 = 38-34%. Land grading to impervious sublayer produced constant depth change in all gullies at the sites. The models for morphometric incremental growth and soil loss volume under the rainfall effect was significantly improved (p<0.05 by bifurcating the lumped annual curve into two growth periods in a year: the periods for increasing rainfall (from week 10-30 and for receding rainfall (from week 31-43 in a year and applying quadratic regressing functions on each (R2 = 91-99%. Rainfall was the principal gully factor and construction delays should be avoided.

O.E. Essien

2012-08-01

64

Soil Orders  

Science.gov (United States)

Developed by the US Department of Agriculture's Soil Survey Division (SSD), here is a high resolution poster with brief descriptions of the soil orders. Photos of soil profiles accompany descriptions of each order. The soil orders include: Alfisols, Andisols, Aridisols, Entisols, Gelisols, Histosols, Inceptisols, Mollisols, Oxisols, Spodusols, Ultisols, and Vertisols.

65

Soil carbonates and soil water  

Science.gov (United States)

The presence of soil carbonates occurring as solidified masses or dispersed particles can alter soil water dynamics from what would be expected based on non-carbonate soil properties. Carbonate minerals in the soil can be derived from high carbonate parent material, additions in the form of carbonat...

66

Perched Soil Zone (PSZ) Aquifer Package for MODFLOW-2005  

Science.gov (United States)

An increasing number of investigators are looking at innovative ways to use precipitation data to calculate recharge to aquifer systems. Typically, simulation models are used to partition precipitation into evapotranspiration, runoff and recharge. Currently, the groundwater flow model, MODFLOW-2005, does not simulate dynamic near-surface hydrologic processes such as, infiltration, hortonian or dunnian runoff, return flow, or the effects of impervious surfaces on runoff. The Perched Soil-Zone package (PSZ) for MODFLOW-2005 is being developed to address these major components of hillslope hydrology for simulating watershed processes in the context of basin-scale groundwater flow modeling. This package extends MODFLOW-2005 capabilities to simulate soil zone processes in short time steps that are integrated to the much longer daily or weekly timesteps typically used in MODFLOW-2005. A perched aquifer often develops in the soil zone during periods of heavy rainfall, delivering interflow to channels in a watershed. The soil zone is the upper most region of the vadose zone where plant and soil processes enhance storage and permeability, providing a fast pathway for water and solutes to streams. The soil zone connects the watershed surface to the deeper unsaturated, and saturated zones. Modeling of soil zone processes has been used to gain understanding of watershed hydrologic processes. The PSZ package can use available data at finer time increments to ensure precipitation is properly distributed between infiltration and runoff. This physically based partitioning of precipitation allows for a more robust estimation of recharge. The PSZ package is intended to be used in basin scale MODFLOW-2005 simulations for efficiently simulating watershed hydrologic processes, especially those processes that partition rainfall into evapotranspiration, runoff, and recharge.

Henson, W.; Niswonger, R. G.

2010-12-01

67

Soil experiment  

Science.gov (United States)

An experimental procedure was devised to investigate the effects of the lunar environment on the physical properties of simulated lunar soil. The test equipment and materials used consisted of a vacuum chamber, direct shear tester, static penetrometer, and fine grained basalt as the simulant. The vacuum chamber provides a medium for applying the environmental conditions to the soil experiment with the exception of gravity. The shear strength parameters are determined by the direct shear test. Strength parameters and the resistance of soil penetration by static loading will be investigated by the use of a static cone penetrometer. In order to conduct a soil experiment without going to the moon, a suitable lunar simulant must be selected. This simulant must resemble lunar soil in both composition and particle size. The soil that most resembles actual lunar soil is basalt. The soil parameters, as determined by the testing apparatus, will be used as design criteria for lunar soil engagement equipment.

Hutcheson, Linton; Butler, Todd; Smith, Mike; Cline, Charles; Scruggs, Steve; Zakhia, Nadim

1987-01-01

68

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

69

Soil Taxonomy  

Science.gov (United States)

From Alfisols to Vertisols, this substantial resource (.pdf format only) from the US Department of Agriculture's Natural Resources Conservation Service provides an in-depth treatment of soil taxonomy around the world. Published in 1999 (Second Edition), this Soil Taxonomy text includes 23 chapters, covering the basics of soil classification through the world distribution of orders and suborders. Soil taxonomy maps are provided separately, highlighting dominant soils in the US, as well as global soil regions. In addition, an Errata sheet lists corrections for the printed text. This magnificent volume will prove useful to researchers, students, and educators, alike.

70

Soil Texture  

Science.gov (United States)

This University of Florida website educates the public about soil texture, which is the distribution of sizes of mineral particles found in soils. After learning the basics about soil separates, students and educators can learn about the USDA textural triangle and the characteristics of the twelve textural classes. Researchers can discover how to determine the correct soil texture in the field. The website addresses the important role soil textures play in the determination of proper land use activities and management practices. Visitors will also find a short discussion about other factors that affect the behavior and qualities of soils.

71

Groundwater Dynamics in Drained Soils of the Bi?-fi eld District  

Directory of Open Access Journals (Sweden)

Full Text Available The main goal of five-year stationary investigations (2001-2006 was to assess groundwater dynamics in the Bi?-field district, as well as the type of soil moistening of agricultural soils spreading over 5838 ha. Detailed hydropedological investigations were carried out in 2000 and a soil map of the region was produced (scale = 1:10000 using universal kriging. Soil investigations identified six pedosystematic units: alluvial-gley, semigley-pseudogley, eugley hypogley, humogley, eugley amphigley and drained soils. Based on permanent monitoring of piezometer groundwater (piezometer depth up to 4.0 m in the period from 2001 to 2006, the following major soil moistening types and subtypes of the separated soil units were determined: semigley-pseudogely, hypogley, humogley, amphigley and drained. Using the correlation method, more intensive groundwater communication was determined in the studied soil profiles with the River Bi? water (r = 0.65-0.69 than with the River Sava water (r = 0.23-0.69, notably in hypogley soils, which cover 54.3% of the studied area. Analysis of the obtained piezometer water level curves indicated a very strong mutual correlation between the groundwater level dynamics in monitored hydrogeological piezometers of 9 m depth (r = 0.87-0.98, as well as a strong correlation (r = 0.75-0.94 between hydrogeological and hydropedological piezometers of 4 m depth. A particularly strong correlation (r = 0.85-0.94 was recorded between hydrogeological and hydropedological piezometers installed in hypogley soil. These data confirm marked vertical communication of groundwater in the deep aquifer with water of the shallow soil aquifer, indicating that the surface layer of the studied area, mainly made up of silty clay loams to silty clays, is not impervious.

Ivan Musta?

2011-03-01

72

Soil Investigations  

Science.gov (United States)

Students learn the basics about soil, including its formation through the cycling of the Earth's materials, as well as its characteristics and importance. They are also introduced to soil profiles and how engineers conduct site investigations to learn about soil quality for development, contamination transport, and assessing the general environmental health of an area.

Integrated Teaching and Learning Program,

73

Overland flow generation on deep soils in Ethiopia (Lake Tana basin): role of soil texture and plough pan  

Science.gov (United States)

Different applications of rainfall/runoff models in Lake Tana basin (Ethiopia) tend to show that on hill slopes there are vast areas that yield a high runoff response and that behave as if the soil would be nearly impervious (up to 20 % of the hilly catchments). This is well beyond the area occupied by rock outcrops. Duricrusts or hardpans of pedogenetic origin are absent in this environment on basaltic rock with mild tropical climate: no silcretes, calcretes or even ferricretes are known to occur in the basin. Field observations show that runoff response from tilled farmlands can however be unexpectedly high, even when deep theoretically well drained Nitisols occur. In the rainy season, rills and ephemeral gullies are created and these often expose a rock-hard plough pan at some 15 cm depth. Due to repeated tillage at constant depth, the downward pressure of the tip of the ox-drawn ard plough compacts the soil aggregates that are located just below the tilled horizon. In this poster we will discuss the need to not only evaluate the effect of soil texture when interpreting rainfall-runoff relations, but also to investigate the structural and hydrological characteristics of such plough pans.

Nyssen, Jan; Dessie, Mekete; Monsieurs, Elise; Poesen, Jean; Admasu, Teshager; Verhoest, Niko; Adgo, Enyew; Deckers, Jozef

2014-05-01

74

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

75

Soil Horizons  

Science.gov (United States)

This activity involves previously collected soils from each horizon of a soil profile. The bags from one soil profile are given to a group and the students put the bags in the proper order. This involves student groups looking at each other's sample bags as well as their own and sharing information. After some discussion, during which the instructor makes certain that the students have gotten the soil samples into their correct horizon sequence, the bags are opened and examined to let the students see the different textures and properties of each horizon. Students will discover that each soil is different due to different bedrock and weathering conditions. Some soils may not show all of the above horizons, while other soils may clearly show the development of each layer. The thickness of the individual layers may vary greatly also.

76

Soil suction  

OpenAIRE

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

77

Impacts of soil erosion  

OpenAIRE

3.1 Definition of soil functions, soil quality and quality targets The identification of soil functions, properties and processes which are affected by soil erosion is needed to evaluate the impacts of erosion on the soil system. Definition of soil loss tolerance according to soil types and environmental characteristics. 3.2 Development of criteria and indicators to assess soil sustainable use and soil protection measures What are the impacts of soil erosion on soil...

Dorren, Luuk; La Rosa, Diego; Theocharopoulos, Sid P.

2004-01-01

78

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 paperthis paper

79

Soil mechanics  

Science.gov (United States)

Preliminary results are presented of an investigation of the physical and mechanical properties of lunar soil on the Descartes slopes, and the Cayley Plains in the vicinity of the LM for Apollo 16. The soil mechanics data were derived form (1) crew commentary and debriefings, (2) television, (3) lunar surface photography, (4) performance data and observations of interactions between soil and lunar roving vehicle, (5) drive-tube and deep drill samples, (6) sample characteristics, and (7) measurements using the SRP. The general characteristics, stratigraphy and variability are described along with the core samples, penetrometer test results, density, porosity and strength.

Mitchell, J. K.; Carrier, W. D., III; Houston, W. N.; Scott, R. F.; Bromwell, L. G.; Durgunoglu, H. T.; Hovland, H. J.; Treadwell, D. D.; Costes, N. C.

1972-01-01

80

Encopresis (Soiling)  

Science.gov (United States)

... Frustrated parents, grandparents, and caregivers may advocate various punishments and consequences for the soiling — which only leaves ... encourage the child throughout treatment. Provide a small incentive, such as a star or sticker on the ...

81

Linking soil biodiversity and agricultural soil management  

OpenAIRE

Soil biodiversity vastly exceeds aboveground biodiversity, and is prerequisite for ecosystem stability and services. This review presents recent findings in soil biodiversity research focused on interrelations with agricultural soil management. Richness and community structure of soil biota depend on plant biodiversity and vice versa. Soil biota govern nutrient cycling and storage, soil organic matter (SOM) formation and turnover. Agriculture manipulates plants, soils and SOM. With intensific...

Thiele-bruhn, S.; Bloem, J.; Vries, F. T.; Kalbitz, K.; Wagg, C.

2012-01-01

82

Physical properties as indicators of oil penetration in soils, contaminated with oil lakes in the Greater Burgan oil fields, Kuwait  

International Nuclear Information System (INIS)

Measurements were made on 60 samples to determine the physical properties of the soil profiles contaminated with oil lakes in Al-Ahmadi and Burgan oil fields which include 80% of the Greater Burgan oil wells in southern Kuwait. The two soil profiles have similar saturation percentages, field capacities, wilting coefficients, low available water capacities due to statificiation and very low matric potential, and high bulk densities due to compaction by vehicle wheels. The fluviatile origin, relatively poor sorting and unstable structure of the Burgan soil layers have led to lower hydraulic conductivity and permeability, thereby restricting oil penetration mainly to the upper 25-45 cm layer. In contrast, the eolian origin, excellent sorting and stable structure of Al-Ahmadi soil layers have resulted in higher hydraulic conductivity and permeability, and hence allowed the spreading of oil over much greater depths (down to 150 cm). The very low values of the hydraulic conductivities and available water capacities of the zone(s) lying below the impervious Gatch (caliche) layer in the two soil profiles suggest that this layer could act as a moisture barrier impeding any further downward oil penetration. 16 refs., 3 figs., 4 tabs

83

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.

84

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

85

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.

86

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.

87

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

88

Soil Enzymes  

Science.gov (United States)

The functionality and resilience of natural and managed ecosystems mainly rely on the metabolic abilities of microbial communities, the main source of enzymes in soils. Enzyme mediated reactions are critical in the decomposition of organic matter, cycling of nutrients, and in the breakdown of herbic...

89

Lunar soil properties and soil mechanics  

Science.gov (United States)

The study to identify and define recognizable fabrics in lunar soil in order to determine the history of the lunar regolith in different locations is reported. The fabric of simulated lunar soil, and lunar soil samples are discussed along with the behavior of simulated lunar soil under dynamic and static loading. The planned research is also included.

Mitchell, J. K.; Houston, W. N.; Hovland, H. J.

1972-01-01

90

SOIL MOISTURE PROBES FOR A DISPERSIVE SOIL  

Science.gov (United States)

Soils high in smectite clays have presented difficulties when using dielectric soil moisture sensors in the field. The purpose of this study was to determine which soil moisture sensor provided reliable data on these soils after site-specific calibration. The CS616 water content reflectometer was co...

91

Soils - Part 4: Soil pH  

Science.gov (United States)

Soil pH is defined and its implications for crop production are described in this lesson. How are soil pH and buffer pH determined? How are these assessments used in lime recommendations? The factors that influence pH variations in soils, the chemistry involved in changing the pH of a soil, and the benefits associated with liming acid soils will be discussed.[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.

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

Soil fertility management: Impacts on soil macrofauna, soil aggregation and soil organic matter allocation.  

OpenAIRE

Maintenance of soil organic matter through integrated soil fertility management is important for soil quality and agricultural productivity, and for the persistence of soil faunal diversity and biomass. Little is known about the interactive effects of soil fertility management and soil macrofauna diversity on soil aggregation and SOM dynamics in tropical arable cropping systems. A study was conducted in a long-term trial at Kabete, Central Kenya, to investigate the effects of organic inputs (...

Ayuke, F. O.; Brussaard, L.; Vanlauwe, B.; Six, J.; Lelei, D. K.; Kibunja, C. N.; Pulleman, M. M.

2011-01-01

94

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.

95

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.)

96

The monitoring of contaminated impervious planar surfaces  

International Nuclear Information System (INIS)

The responses of several types of surface contamination monitor have been investigated for three typical working surfaces contaminated by three radionuclides commonly used in diagnostic or analytical biomedical applications. Of the three radionuclides, 99mTc is an intermediate-energy gamma emitter, 125I decays by electron capture, emitting low-energy x-rays, and 32P is a moderate-energy beta emitter. For each radionuclide monitored values have generally been found to be within 30% of projected response, this being based on calibrations which make use of standard radionuclide sources and conditions. The several types of contaminated non-absorbent surface that have been investigated produce monitored values which for a given type of monitor and radionuclide cannot be differentiated from each other. (author)

97

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

98

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,

99

Soil Science - 9th Grade  

Science.gov (United States)

What are four different soils in Alabama, and what are the charastics First, Read the Soil Regions page. Soil Regions Second, read the page discussing soil types. Read about the first four soil types. Soil Types Third, Please read the information relating to Marine Sediment soils. In this case, you will be learning about the Dothan variety of Marine Sediment soil. Marine Sediment Soils (Dothan Soils) Here is some useful information on Granite Soils, ...

Mr. Allred

2011-04-06

100

NSSC Soil Survey Laboratory: Soil Characterization Database  

Science.gov (United States)

The National Soil Survey Center (NSSC), as part of the Natural Resource Conservation Service, maintains the Soil Survey Laboratory Soil Characterization Database. The application allows users to generate, print and download reports containing soil characterization data held by the NSSC Soil Survey Laboratory. Users are able to choose the location and particular pedon for each query and report generation. The reports are titled Primary Characterization Data and contain the site location, pedon number, sample layer depth, percentage of various sized soil particles, bulk density, water content, mineral content, and much more. Scientists and other professionals will appreciate the easy access to valuable information the site provides.

101

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

102

DEVELOPING WEED SUPPRESSIVE SOILS THROUGH IMPROVED SOIL QUALITY MANAGEMENT  

Science.gov (United States)

Sustainable agriculture is based in part on efficient management of soil microorganisms for improving soil quality. However, identification of biological indicators of soil quality for predicting weed suppression in soils has received little attention. We investigated differences in soil microbial ...

103

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.

Keith Addison

2010-01-01

104

Soil moisture: Some fundamentals. [agriculture - soil mechanics  

Science.gov (United States)

A brief tutorial on soil moisture, as it applies to agriculture, is presented. Information was taken from books and papers considered freshman college level material, and is an attempt to briefly present the basic concept of soil moisture and a minimal understanding of how water interacts with soil.

Milstead, B. W.

1975-01-01

105

MILESTONES IN SOIL PHYSICS  

Science.gov (United States)

This special issue of “Soil Science“ celebrates the enormous accomplishments made during the past century or more in the field of soil science, including some of the key articles published in Soil Science during its 90 years of existence. In this article, we focus on the contributions in soil physic...

106

PRODUCTIVITY OF SOILS  

Science.gov (United States)

This contribution to the Encyclopedia of Soils in the Environment focuses on soil productivity, a concept that encompasses soil fertility plus the inherent and management-related factors affecting plant growth and development. Soil productivity is generally measured in terms of inputs versus outputs...

107

Soil Classification and Treatment.  

Science.gov (United States)

This instructional unit was designed to enable students, primarily at the secondary level, to (1) classify soils according to current capability classifications of the Soil Conservation Service, (2) select treatments needed for a given soil class according to current recommendations provided by the Soil Conservation Service, and (3) interpret a…

Clemson Univ., SC. Vocational Education Media Center.

108

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

Douglas Kowalewski

109

Soil organic matter studies  

International Nuclear Information System (INIS)

A total of 77 papers were presented and discussed during this symposium, 37 are included in this Volume II. The topics covered in this volume include: biochemical transformation of organic matter in soils; bitumens in soil organic matter; characterization of humic acids; carbon dating of organic matter in soils; use of modern techniques in soil organic matter research; use of municipal sludge with special reference to heavy metals constituents, soil nitrogen, and physical and chemical properties of soils; relationship of soil organic matter and plant metabolism; interaction between agrochemicals and organic matter; and peat. Separate entries have been prepared for those 20 papers which discuss the use of nuclear techniques in these studies

110

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

Mark Sweeney

111

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

112

Soil Erosion Studies  

OpenAIRE

Soil erosion affects a large part of the Earth surface, and accelerated soil erosion is recognized as one of the main soil threats, compromising soil productive and protective functions. The land management in areas affected by soil erosion is a relevant issue for landscape and ecosystems preservation. In this book we collected a series of papers on erosion, not focusing on agronomic implications, but on a variety of other relevant aspects of the erosion phenomena. The book is divided into th...

Godone, Danilo Francesco; Stanchi, Silvia

2011-01-01

113

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)

114

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

115

Soil Chapter-Soil: The Great Decomposer  

Science.gov (United States)

In this hands-on activity, students conduct bottle experiments to learn about the conditions that best facilitate the decomposition of organic material in soil. In the lab, they observe changes in the decomposition of vegetable scraps by varying the temperature, moisture and light conditions. This is a learning activity associated with the GLOBE soil investigations and is supported by the Soil chapter of the GLOBE Teacher's Guide.

2012-08-03

116

Diffusion in soil crumbs  

International Nuclear Information System (INIS)

In a multi-component system matter can move as a result of mass-flow and by diffusion. In soil both means of transport occur, but while mass-flow is largely restricted to the coarse pores between the soil aggregates (crumbs), transport by diffusion prevails inside the soil crumbs where the media in which diffusion occurs (water and air) are held in the fine pores by capillary forces. A similar situation exists in compacted (structureless) soil but as soil with a crumb-structure is the normal and more favourable medium for plant growth, a discussion of diffusion in soil crumbs is desirable

117

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

118

Soil Profile Homework  

Science.gov (United States)

This is one of 4 homework assignments given to students throughout this introductory soils course. The main goal of these assignments are to give the students practice with the mechanics of problem solving, conversion, and soil profile descriptions.

Daniel Hirmas

119

Enterovirus inactivation in soil.  

Science.gov (United States)

The inactivation of radioactively labeled poliovirus type 1 and coxsackievirus B 1 in soils saturated with surface water, groundwater, and septic tank liquor was directly proportional to temperature. Virus persistence was also related to soil type and the liquid amendment in which viruses were suspended. At 37 degrees C, no infectivity was recovered from saturated soil after 12 days; at 4 degrees C, viruses persisted for at least 180 days. No infectivity was recovered from dried soil regardless of temperature, soil type, or liquid amendment. Additional experiments showed that evaporation of soil water was largely responsible for the decreased recovery of infectivity from drying soil. Increased rates of virus inactivation at low soil moisture levels were also demonstrated. PMID:44178

Yeager, J G; O'Brien, R T

1979-10-01

120

Soil properties controlling infiltration in volcanic soils  

Science.gov (United States)

Soil water infiltration is an important process whose behaviour depends on external factors and soil properties that vary depending on the type of soil. The soil parameters affecting the infiltration capacity of six soil orders all formed on volcanic materials (andisols, vertisols, alfisols, aridisols, inceptisols, and entisols) and contribute to the differences between them were studied in this paper. A total of 108 sites were selected on the island of Tenerife (Spain). The main soil properties were analysed and the steady-state infiltration rate measured using a double-ring infiltrometer. The relationship between the soil properties and infiltration was modelled using statistical Principal Components Analysis and regressions. The research concludes that the relation between structural development and texture play a decisive role. The high structural development of non-vitric andisols, due to the high organic matter and short-range-order mineral content, leads to an extremely fast infiltration rate. The structural instability and fine texture of aridisols produce low infiltration. In less developed soils (entisols and vitric andisols) where aggregate formation is minimal or non-existent, the coarse grain size is the relevant factor determining their very fast and extremely fast infiltration. In vertisols and alfisols, which have strong aggregation but low stability, clay type and content play an important role and lead to a moderate and moderately fast steady-state infiltration rate, respectively. In the most typic inceptisols, with moderate structural development and stability, the balance of the properties is largely responsible for the intermediate infiltration rate observed.

Neris, Jonay; Tejedor, Marisa; Jiménez, Concepción

2013-04-01

121

Dielectric characterisation of soil.  

OpenAIRE

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

122

Iodine dynamics in soils  

OpenAIRE

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...

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

2012-01-01

123

Soil function and "malfunction"  

OpenAIRE

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 a...

Elio Coppola; Andrea Buondonno

2008-01-01

124

Soil Compaction and Drainage  

Science.gov (United States)

This bulletin, authored by N.R. Fausey and B.H. Nolte for Ohio State University, describes soil compaction and its effect on drainage and crops in situations of surface soil compaction and deep soil compaction. Contains links to research, discussions and conclusions.

Fausey, N.R.

125

Restoration of contaminated soils  

International Nuclear Information System (INIS)

A great variety of techniques are used for the restoration of contaminated soils. The contamination is present by both organic and inorganic pollutants. Environmental conditions and soil characteristics should take into account in order to implement a remedial technique. The bioremediation technologies are showed as help to remove a variety of soil contaminants. (author)

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

Bioindication with soil microfauna  

International Nuclear Information System (INIS)

The state of a soil can be characterised through its inhabitant micro-, meso-, and macrofauna. For an appropriate assessment of soil quality at least one representative of each of these size categories should be studied (e.g. testacea, mites, earthworms). This contribution summarizes the insights gained from microscopic soil fauna in this context. The following practical examples are discussed: pesticides, organic and artificial fertilisers, soil compaction, ecological and conventional farming, recolonisation. The 'weighted cenosis index' represents a quantitative measure for the influence of anthropogenic activity on a soil. (orig.)

128

Plutonium association in soils  

International Nuclear Information System (INIS)

This paper reviews the association of plutonium in the soils and sediments of several contaminated environmental samples. The plutonium-matrix association based on selected chemical treatments is reviewed. The association of plutonium with the soil particle sizes is reviewed and a soil plutonium index is derived for several contaminated sites to permit comparison of the potential transfer to man via the inhalation pathway. The soil plutonium index accounts for the fraction of the total activity in the resuspendible sizes, the relative concentration of the activity on the soil particle, and the potential lung deposition upon inhalation. The derived soil plutonium indices for four sites range from 0.52 to 1.26 from the least to the most severely contaminated site. The order of increasing site severity is the Nevada Test Site (0.52), Oak Ridge National Laboratory (0.69), Mound Laboratory (1.18), and Rocky Flats (1.26). Limitations of the soil factor are discussed

129

From soil in art towards Soil Art  

Science.gov (United States)

The range of art forms and genres dealing with soil is wide and diverse, spanning many centuries and artistic traditions, from prehistoric painting and ceramics to early Renaissance works in Western literature, poetry, paintings, and sculpture, to recent developments in cinema, architecture and contemporary art. Case studies focused on painting, installation, and cinema are presented with the view of encouraging further exploration of art about, in, with, or featuring soil or soil conservation issues, created by artists, and occasionally scientists, educators or collaborative efforts thereof.

Feller, C.; Landa, E. R.; Toland, A.; Wessolek, G.

2015-02-01

130

Soil gas technology  

Energy Technology Data Exchange (ETDEWEB)

A rapid method of detecting and delineating the aerial extent of groundwater and soil contamination by volatile organic chemicals (VOCs) has been developed. The remote detection technique traces VOCs in groundwater or soil via their presence in the shallow soil gas. The presence of volatile organic chemicals (VOCs) in shallow soil gas indicates the observed compounds may either be in the vadose zone near the probe or in groundwater below the probe. The soil gas technology is most effective in mapping low molecular weight halogenated solvent chemicals and petroleum hydrocarbons possessing high vapor pressures and low aqueous solubilities. These compounds readily partition out of the groundwater and into the soil gas as a result of their high gas/liquid partitioning coefficients. Once in the soil gas, VOCs diffuse vertically and horizontally through the soil to the ground surface where they dissipate into the atmosphere. The contamination acts as a source and the above ground atmosphere acts as a sink, and typically a concentration gradient develops between the two. This book describes two investigations which were performed using soil gas contaminant technologies. These case studies provide an outline of the applications of soil gas investigations.

Favero, M.D.; Thompson, G.M. (Tracer Research Corp., Tucson, AZ (USA))

1988-01-01

131

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)

132

Characterization of Dispersive Soils  

OpenAIRE

Dispersive soils which occur in many parts of the world are easily erodible and segregate in water pose serious problems of stability of earth and earth retaining structures. The mechanism of dispersivity of soils is reasonably well understood. However there is simple method to identify the dispersivity of the soils and even more difficult to quantify the dispersivity. Visual classification, Atterberg’s limits and particle size analysis do not provide sufficient basis to differentiate betwe...

Dinesh, S. V.; Sivapullaiah, Puvvadi V.; Umesh, T. S.

2011-01-01

133

Photocatalytic Soil Decontamination  

OpenAIRE

A photocatalytic treatment is evaluated for the decontamination of soils containing 2-chlorophenol, 2,7-dichlorodibenzodioxin and atrazine. In the laboratory the contaminated soils were mixed with a photocatalyst (TiO2) in a aqueous slurry (up to 60 g L-1 of solid mixture) and exposed to simulated solar radiation. The organic contaminants were destroyed in relatively short time. On this basis photocatalytic processes could be effective chemical detoxification methods for contaminated soils.

Minero, Claudio; Pelizzetti, Ezio

1992-01-01

134

Soil Classification Using GATree  

OpenAIRE

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...

Bhargavi, P.; Jyothi, Dr S.

2010-01-01

135

Radioisotopes in soil science  

International Nuclear Information System (INIS)

Soils form a thin veneer of the Earth that sustain the entire flora and fauna of the terra firma. To that extent the soil as a natural resource is very precious and needs to be managed in a sustainable manner. The fate of degradation of pesticides in soil and build-up of heavy metals in the overall biosafety scenario is also studied gainfully using radioisotopes. Radioisotopes are a very potent tool in the hands of the Soil Scientists, perhaps, the most important among the peaceful applications in service of the mankind

136

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.

137

Investigation of Wetland Soil Properties affecting Optimum Soil Cultivation  

OpenAIRE

An investigation was carried out on wetland (fadama) soil properties affecting optimum soil cultivation. A cone penetrometerand a shear vane apparatus (19 mm) were used to determine the cone index and the torque that cause the soil to shearat different moisture contents. The study shows that the cone index and shear vane of fadama soils increased with depth anddecreased with increase in moisture content. High moisture content reduced the soil cohesion. The internal frictional angleof the soil...

Babatunde, O. O.; Adeniran, K. A.

2010-01-01

138

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 qumatoda. ? The soil biological quality index QBS index was most appropriate for soil quality assessment. - Soil metal contamination negatively affected soil invertebrate abundance and diversity.

139

Classiology and soil classification  

Science.gov (United States)

Classiology can be defined as a science studying the principles and rules of classification of objects of any nature. The development of the theory of classification and the particular methods for classifying objects are the main challenges of classiology; to a certain extent, they are close to the challenges of pattern recognition. The methodology of classiology integrates a wide range of methods and approaches: from expert judgment to formal logic, multivariate statistics, and informatics. Soil classification assumes generalization of available data and practical experience, formalization of our notions about soils, and their representation in the form of an information system. As an information system, soil classification is designed to predict the maximum number of a soil's properties from the position of this soil in the classification space. The existing soil classification systems do not completely satisfy the principles of classiology. The violation of logical basis, poor structuring, low integrity, and inadequate level of formalization make these systems verbal schemes rather than classification systems sensu stricto. The concept of classification as listing (enumeration) of objects makes it possible to introduce the notion of the information base of classification. For soil objects, this is the database of soil indices (properties) that might be applied for generating target-oriented soil classification system. Mathematical methods enlarge the prognostic capacity of classification systems; they can be applied to assess the quality of these systems and to recognize new soil objects to be included in the existing systems. The application of particular principles and rules of classiology for soil classification purposes is discussed in this paper.

Rozhkov, V. A.

2012-03-01

140

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

141

Soil and Culture  

Science.gov (United States)

Editors Ed Landa and Christian Feller have assembled an international ensemble cast of writers, artists, historians, philosophers, and scientists of broad perspective to create a book of truly fascinating reading for any soils enthusiast. When so little we see in print is truly new or original, Soil...

142

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

143

The Soil Series in Soil Classifications of the United States  

Science.gov (United States)

Organized national soil survey began in the United States in 1899, with soil types as the units being mapped. The soil series concept was introduced into the U.S. soil survey in 1903 as a way to relate soils being mapped in one area to the soils of other areas. The original concept of a soil series was all soil types formed in the same parent materials that were of the same geologic age. However, within about 15 years soil series became the primary units being mapped in U.S. soil survey. Soil types became subdivisions of soil series, with the subdivisions based on changes in texture. As the soil series became the primary mapping unit the concept of what a soil series was also changed. Instead of being based on parent materials and geologic age, the soil series of the 1920s was based on the morphology and composition of the soil profile. Another major change in the concept of soil series occurred when U.S. Soil Taxonomy was released in 1975. Under Soil Taxonomy, the soil series subdivisions were based on the uses the soils might be put to, particularly their agricultural uses (Simonson, 1997). While the concept of the soil series has changed over the years, the term soil series has been the longest-lived term in U.S. soil classification. It has appeared in every official classification system used by the U.S. soil survey (Brevik and Hartemink, 2013). The first classification system was put together by Milton Whitney in 1909 and had soil series at its second lowest level, with soil type at the lowest level. The second classification system used by the U.S. soil survey was developed by C.F. Marbut, H.H. Bennett, J.E. Lapham, and M.H. Lapham in 1913. It had soil series at the second highest level, with soil classes and soil types at more detailed levels. This was followed by another system in 1938 developed by M. Baldwin, C.E. Kellogg, and J. Thorp. In this system soil series were again at the second lowest level with soil types at the lowest level. The soil type concept was dropped and replaced by the soil phase in the 1950s in a modification of the 1938 Baldwin et al. classification (Simonson, 1997). When Soil Taxonomy was released in 1975, soil series became the most detailed (lowest) level of the classification system, and the only term maintained throughout all U.S. classifications to date. While the number of recognized soil series have increased steadily throughout the history of U.S. soil survey, there was a rapid increase in the recognition of new soil series following the introduction of Soil Taxonomy (Brevik and Hartemink, 2013). References Brevik, E.C., and A.E. Hartemink. 2013. Soil maps of the United States of America. Soil Science Society of America Journal 77:1117-1132. doi:10.2136/sssaj2012.0390. Simonson, R.W. 1997. Evolution of soil series and type concepts in the United States. Advances in Geoecology 29:79-108.

Indorante, Samuel; Beaudette, Dylan; Brevik, Eric C.

2014-05-01

144

The Changing Model of Soil  

Science.gov (United States)

The contemporary genetic model of soil is changing rapidly in response to advances in soil science and to human and environmental forcings in the 21st century (Richter and Yaalon, 2012). Three ongoing changes in the model of soil include that: (1) lower soil boundaries are much deeper than the solum, historically the O to B horizons, (2) most soils are polygenetic paleosols, products of soil-forming processes that have ranged widely over soils' lifetimes, and (3) soils are globally human-natural bodies, no longer natural bodies. Together, these changes in the model of soil mean that human forcings are a global wave of soil polygenesis altering fluxes of matter and energy and transforming soil thermodynamics as potentially very deep systems. Because soils are non-linear systems resulting from high-order interactions of physics, chemistry, and biology, trajectories of how human forcings alter soils over decades are not readily predictable and require long-term soil observations. There is much to learn about how soils are changing internally as central components of management systems and externally in relation to wider environments. To be critical, research has been remarkably superficial in studies of soil, reductionist in approach, and lacking in time-series observations of responses to soil management. While this criticism may sound negative, it creates significant opportunities for contemporary soil scientists.

Richter, D. D.; Yaalon, D.

2012-12-01

145

Characterization of Dispersive Soils  

Directory of Open Access Journals (Sweden)

Full Text Available Dispersive soils which occur in many parts of the world are easily erodible and segregate in water pose serious problems of stability of earth and earth retaining structures. The mechanism of dispersivity of soils is reasonably well understood. However there is simple method to identify the dispersivity of the soils and even more difficult to quantify the dispersivity. Visual classification, Atterberg’s limits and particle size analysis do not provide sufficient basis to differentiate between dispersive clays and ordinary erosion resistant clays. Pinhole test and double hydrometer test are the only two tests that are in vogue to identify the dispersive soils. This paper explores the possibility of using other standard tests such as shrinkage limit and unconfined compressive strength tests to quantify the dispersivity of the soils. The rationale of using the methods and correlation between the dispersivity determined by various methods has been explained. It has been concluded that dispersivity ascertained from strength tests is more reliable.

S. V. Dinesh

2011-06-01

146

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

147

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

148

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 thed 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)

149

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

150

Soil bacteria for remediation of polluted soils  

International Nuclear Information System (INIS)

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

151

Soil survey, soil databases and soil monitoring in Spain  

OpenAIRE

Meetings of European Union Heads of Soil Survey Organisations were held in 1989 and 1994 respectively. Both were followed by publication of monographs describing the state-of-the-art in each of the member countries (Hodgson 1991; Le Bas & Jamagne 1996). Limited progress has been made in Spain since then, except for a proposal for an ambitious macroproject (PNCTA), the prospects for which now seem somewhat uncertain. Readers interested in historical aspects of Spanis...

Iba?n?ez Marti?n, Juan Jose?; Sa?nchez Di?az, Juan; La Rosa, Diego; Alba, S.

1999-01-01

152

Soil fauna, soil properties and geo-ecosystem functioning  

Science.gov (United States)

The impact of soil fauna on soil processes is of utmost importance, as the activity of soil fauna directly affects soil quality. This is expressed by the direct effects of soil fauna on soil physical and soil chemical properties that not only have great importance to food production and ecosystems services, but also on weathering and hydrological and geomorphological processes. Soil animals can be perceived as ecosystem engineers that directly affect the flow of water, sediments and nutrients through terrestrial ecosystems. The biodiversity of animals living in the soil is huge and shows a huge range in size, functions and effects. Most work has been focused on only a few species such as earthworms and termites, but in general the knowledge on the effect of soil biota on soil ecosystem functioning is limited as it is for their impact on processes in the soil and on the soil surface. In this presentation we would like to review some of the impacts of soil fauna on soil properties that have implications for geo-ecosystem functioning and soil formation processes.

Cammeraat, L. H.

2012-04-01

153

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

154

Managing soil under vegetable production to improve soil quality  

Science.gov (United States)

Over the years, soil quality has eroded as soil organic matter has declined on farms across North Carolina. This study is assessing the effects of tillage practice, winter cover cropping and compost use on changes in soil function and improvement in soil quality under vegetable production. The field...

155

Calorimetry and soil  

International Nuclear Information System (INIS)

This paper is a review about the application of calorimetry to study soil properties and its metabolism. Although this research has increased slowly but continuously during the last 30 years, it is true that it has received poor attention. One reason for that could be the complexity of the soil and the difficulties to investigate it from a thermodynamic point of view. In this paper we would like to demonstrate that calorimetry constitutes a very suitable method to face the main topics related to soil quality and activity. Very well known indicators used in soil research can be measured by different thermal and calorimetric methods such as differential scanning calorimetry (DSC), thermogravimetry (TG) and isothermal calorimetry (ITC). TG and DSC are both temperature scanning methods used for estimation of certain properties of the soil material such as organic matter, ignition temperature, humification index, quartz content, so on, whereas the study of the soil microbial metabolism is conducted under essentially isothermal conditions by ITC. In this review, the contributions of these techniques to different topics in soil research are described and their importance for the environmental concern is discussed in the light of this new era

156

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

157

Climate Strategic Soil Management  

Directory of Open Access Journals (Sweden)

Full Text Available 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 frequency of extreme events, the decreasing resilience of agroecosystems, an increasing income and affluent lifestyle with growing preference towards meat-based diet and a decreasing soil quality and use efficiency of inputs. Reversing these downward spirals implies the implementation of proven technologies, such as conservation agriculture, integrated nutrient management, precision agriculture, agroforestry systems, etc. Restoration of degraded soil and desertified ecosystems and the creation of positive soil and ecosystem C budgets are important. Urban agriculture and green roofs can reduce the energy footprint of production chains for urban and non-urban areas and enhance the recycling of by-products. Researchable priorities include sustainable land use and soil/water management options, judicious soil governance and modus operandi towards payments to land managers for the provisioning of ecosystem services.

Rattan Lal

2014-02-01

158

Soil-radionuclide interactions  

International Nuclear Information System (INIS)

Radionuclide mobility in agricultural systems, and thus in the food chain, is strongly affected by the extension of its sorption in soils, which can be estimated by the quantification of the solid-liquid distribution coefficient (Kd). This parameter may vary within various orders of magnitude depending on the radionuclide and soil combination, but also on the experimental method used for its determination. Here, a new Kd database was built up with around 2900 records of 67 elements, which allows us to calculate the best estimates for the Kd values of a number of radionuclides for various soil types. Best estimates are derived from geometric means calculated from grouping soils by texture and organic matter content and, when possible, also using the main soil cofactors governing soil-radionuclide interaction, concretely for radiocaesium, radiostrontium, uranium, radioiodine, and a few heavy-metal radionuclides. The use of the cofactor approach permits, in most cases, decreasing the variability of the ranges of Kd values associated with a soil type. Additionally, some hints are given in this section on the sorption dynamics of radiostrontium and radiocaesium, based on rate constants values and changes with time in the reversibly sorbed fraction. (author)

159

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

160

Soil washing treatability study  

Energy Technology Data Exchange (ETDEWEB)

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.

Krstich, M.

1995-12-01

161

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

162

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)

163

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

164

Theoretical earth temperature profiles for different soils and soil conditions  

Energy Technology Data Exchange (ETDEWEB)

The annual temperature variations in earth with depth from the surface offers, by its natural characteristics, a phase lag and reduced variation in the maximum and minimum temperatures. The temperature profiles vary for different soils and soil conditions. Soil temperatures are found to be an explicit function of soil thermal properties, particularly the thermal diffusivity. The earth temperatures stabilize at certain depth, where the annual swings in temperature are negligible and this stabilizing depth varies for different soils. A simple first harmonic approximation method has been used to predict the temperature variations as a function of depth and time for different soils (ordinary light soils, heavy soil, organic soil and sand) and soils conditions (dry, damp and wet). The results are a helpful indicator for deciding external design temperatures for the design of earth sheltered or ground coupled spaces. (author) 5 figs., 1 tab., 17 refs.

Sujit Kumar, G.; Kaushik, S.C. [Inst. of Technology, Centre for energy Studies, New Delhi (India)

1995-12-31

165

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

166

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

167

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)

168

MICROBIAL INDICATORS OF SOIL QUALITY  

Science.gov (United States)

Soil quality is an elusive term; however, the quality of a soil can greatly impact land use, sustainability, and productivity. Soil microbial processes are an integral part of soil quality and a better understanding of these processes and microbial community structure is needed. ...

169

HOW SOIL FORMING PROCESSES DETERMINE SOIL-BASED VITICULTURAL ZONING  

Scientific Electronic Library Online (English)

Full Text Available The aim of this study was to elucidate the soil forming processes of representative vineyard soils, and to discuss the implications on a soil-based viticultural zoning at very detailed scale. The study area is located in Priorat, Penedes and Conca de Barbera viticultural areas (Catalonia, North-east [...] ern Spain). The studied soils belong to representative soil map units determined at 1:5,000 scale, according to Soil Taxonomy classification. The soil forming processes, identified through morphological and micromorphological analyses, have significant effects on some soil properties. For example, the different processes of clay accumulation in soils developed from granodiorites in Priorat or gravel deposits in Conca de Barbera, are primarily responsible for significant differences in clay content, available water capacity and cation exchange capacity. These soils properties, especially those related to soil moisture regime, have a direct influence on vineyard management and grape quality. However, soil forming processes are not always reflected on soil classification, especially in soils modified by man. We show that climate or geology alone cannot be used in viticultural zoning at very detailed scale, unless soil forming processes are taken into account.

J.M, Ubalde; X, Sort; R.M, Poch.

170

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)

171

Thermal soil remediation  

Energy Technology Data Exchange (ETDEWEB)

The environmental properties and business aspects of thermal soil remediation are described. Thermal soil remediation is considered as being the best option in cleaning contaminated soil for reuse. The thermal desorption process can remove hydrocarbons such as gasoline, kerosene and crude oil, from contaminated soil. Nelson Environmental Remediation (NER) Ltd. uses a mobile thermal desorption unit (TDU) with high temperature capabilities. NER has successfully applied the technology to target heavy end hydrocarbon removal from Alberta`s gumbo clay in all seasons. The TDU consist of a feed system, a counter flow rotary drum kiln, a baghouse particulate removal system, and a secondary combustion chamber known as an afterburner. The technology has proven to be cost effective and more efficient than bioremediation and landfarming.

Nelson, D. [Nelson Environmental Remediation Ltd., Spruce Grove, AB (Canada)

1999-04-01

172

Constipation and Fecal Soiling  

Science.gov (United States)

... over these bowel movements and should not be punished for soiling episodes. They are often embarrassed by ... well to a carefully planned, consistent system of rewards for appropriate behaviors. Parents can develop behavior modifications ...

173

Thermal soil remediation  

International Nuclear Information System (INIS)

The environmental properties and business aspects of thermal soil remediation are described. Thermal soil remediation is considered as being the best option in cleaning contaminated soil for reuse. The thermal desorption process can remove hydrocarbons such as gasoline, kerosene and crude oil, from contaminated soil. Nelson Environmental Remediation (NER) Ltd. uses a mobile thermal desorption unit (TDU) with high temperature capabilities. NER has successfully applied the technology to target heavy end hydrocarbon removal from Alberta's gumbo clay in all seasons. The TDU consist of a feed system, a counter flow rotary drum kiln, a baghouse particulate removal system, and a secondary combustion chamber known as an afterburner. The technology has proven to be cost effective and more efficient than bioremediation and landfarming

174

Mycorrhizas and tropical soil fertility  

OpenAIRE

Major factors that constrain tropical soil fertility and sustainable agriculture are low nutrient capital, moisture stress, erosion, high P fixation, high acidity with aluminium toxicity, and low soil biodiversity. The fragility of many tropical soils limits food production in annual cropping systems. Because some tropical soils under natural conditions have high biological activity, an increased use of the biological potential of these soils to counter the challenges of food production probl...

Cardoso, I. M.; Kuyper, T. W.

2006-01-01

175

Soil strength and forest operations.  

OpenAIRE

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

176

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

177

CONSIDERATIONS ON SOIL CARBON MANAGEMENT  

OpenAIRE

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, worldwi...

Adriana Nicoleta Ungura?u; Florian St?tescu

2012-01-01

178

Soil decontamination study, DOE facilities  

International Nuclear Information System (INIS)

Research activities related to soil decontamination at Rocky Flats are summarized. The prospect of using soil decontamination methods for decontaminating transuranic (TRU) wastes is good. The approach is to remove the activity by attrition scrubbing followed by dispersion. Significant similarities and differences among soils from 5 DOE sites are discussed. Current guidelines for contaminated soils (actinides) are listed. Criteria for the disposition soil generated in the decontamination process are given. Several decontamination tests are described

179

Automated soil gas monitoring chamber  

Science.gov (United States)

A chamber for trapping soil gases as they evolve from the soil without disturbance to the soil and to the natural microclimate within the chamber has been invented. The chamber opens between measurements and therefore does not alter the metabolic processes that influence soil gas efflux rates. A multiple chamber system provides for repetitive multi-point sampling, undisturbed metabolic soil processes between sampling, and an essentially airtight sampling chamber operating at ambient pressure.

Edwards, Nelson T.; Riggs, Jeffery S.

2003-07-29

180

Climate Strategic Soil Management  

OpenAIRE

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

181

Soil micromorphological study for assessment of soil porous system, soil hydraulic properties and structure stability.  

Czech Academy of Sciences Publication Activity Database

Ro?. 8, - (2006). ISSN 1029-7006. [EGU General Assembly 2006. 02.04.2006-07.04.2006, Vienna] Institutional research plan: CEZ:AV0Z30130516 Keywords : soil micromorphology * soil porous system * soil hydraulic Subject RIV: DF - Soil Science http://www.cosis.net/abstracts/EGU06/10474/EGU06-J-10474-5.pdf

Kodešová, R.; Žigová, Anna; Rohošková, M.; Kodeš, V.; Kutílek, M.

2006-01-01

182

Metals in European roadside soils and soil solution – A review  

International Nuclear Information System (INIS)

This review provides a summary of studies analysing metal concentrations in soils and soil solution at European roadsides. The data collected during 27 studies covering a total of 64 sites across a number of European countries were summarised. Highest median values of Cr, Cu, Ni, Pb, and Zn were determined in the top soil layer at the first 5 m beside the road. Generally, the influence of traffic on soil contamination decreased with increasing soil depth and distance to the road. The concentration patterns of metals in soil solution were independent from concentrations in the soil matrix. At 10-m distance, elevated soil metal concentrations, low pH, and low percolation rates led to high solute concentrations. Directly beside the road, high percolation rates lead to high annual loadings although solute concentrations are comparatively low. These loadings might be problematic, especially in regions with acidic sandy soils and a high groundwater table. - Highlights: • Summary of studies analysing metals in soils and soil solution at European roadsides. • Metal concentrations in topsoil 5 m beside the road are influenced strongly by traffic. • Solute concentrations of metals are mostly independent from soil concentrations. • High percolation rates lead to high annual loadings directly beside the road. - Summarised data showed typical distance related metal patterns of European roadside soils; solute concentrations are mostly independent from soil matrix concentr

183

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)

184

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

Science.gov (United States)

The 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

185

The Influence of Soil Particle on Soil Condensation Water  

OpenAIRE

The experiment results showed that the indoor experiment formed from the volume of soil hygroscopic water increased gradually with decreasing size of soil particles. In the outdoor experiments, the results showed that the formed condensation water in medium sand was greater than it was in fine sand; the soil hot condensation water was mainly formed in the top layer of soil between 0-5 cm. We also found that covering the soil surface with stones can increase the volume of formed soil condensat...

Hou Xinwei; Chen Hao; Li Xiangquan; Cui Xiaomei; Liu Lingxia; Wang Zhenxing

2013-01-01

186

GLOBE Videos: Soil Characterization - Soil Moisture (18:23 min)  

Science.gov (United States)

This video describes how to select a soil moisture study site and sampling strategy, and identifies what laboratory instruments will be needed to complete a soil moisture analysis. Students are shown collecting soil moisture data and asking questions about what soil moisture data might tell them about the environment. The resource includes a video and a written transcript, and is supported by the Soil Moisture Protocol in the GLOBE Teacher's 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.

187

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

188

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

189

Soil-atmosphere greenhouse-gas exchange in a bioretention system  

Science.gov (United States)

Bioretention systems are a popular green-technology for the management of urban stormwater runoff in many countries. They typically consist of a trench filled with a highly permeable soil medium that supports vegetation; runoff is diverted to bioretention systems and, by percolating through the filter medium, is subjected to a number of treatment processes. Nitrogen (N) is one of the key pollutants targeted by bioretention systems, which are able to reduce N concentrations considerably from inflow to outflow. To increase N removal, a saturated zone at the bottom of the filter medium is often artificially generated, to both enhance the denitrification process and increase the water available to the vegetation between inflow events. Although studies on the N-removal performance of bioretention systems are widely available in the literature, less is known about the exchange of greenhouse gases (GHG), especially nitrous oxide (N2O), between the bioretention systems and the atmosphere. Here, we present an experimental pilot study to measure N2O and CO2 soil emissions in a bioretention system installed on the Clayton Campus of Monash University in Melbourne, Australia. The bioretention system is divided into three cells, each 15 m2; the system as a whole receives water run-off from 4500 m2 of impervious car park. We monitored two cells with mostly sandy-loam vegetated with native sedges (mainly Carex Appressa and Lomandra Longifolia), one with and one without a saturated zone. Three manual flux chambers were installed in both cells. Gas flux samples were taken twice a week at about 11 am between the 2nd of March and the 18th of May 2011 (late summer and fall). Since October 2010, air-phase soil CO2 concentration profiles were measured continuously using solid-state infrared CO2 transmitters (GMT-221 model, Vaisala, Finland), along with soil moisture and soil temperature. Preliminary analysis of the chamber data (March only) showed that N2O fluxes were in general below 50 ?g N/ (m2 h) with occasional pulse emissions > 150 ?g N /(m2 h) after recent inflow events. Fluxes from the cell with the saturated zone were consistently higher than those from the cell without a saturated zone. CO2 fluxes were comparable between the two cells, and usually between 50 and 200 mg C/(m2 h) whilst temperatures ranged between 12 and 26 degrees Celsius through this late summer/autumn period. Results from the entire data-set (March-May) will be presented along with an investigation of the relationship between these fluxes and other environmental and soil variables, such as soil nitrate and ammonium content and soil redox potential. Seasonal fluctuations and the effect of random inflow pulses will be also assessed and discussed. The results from this pilot study are useful to provide direct quantification of the GHG emissions associated with urban bioretention systems, which are one of the most used green infrastructures to manage stormwater runoff.

Daly, E.; Chan, H.; Beringer, J.; Livesley, S. J.

2011-12-01

190

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

191

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

192

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

193

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

194

Effect of soil texture on the microwave emission from soils  

Science.gov (United States)

The intensity brightness temperature of the microwave emission from the soil is determined primarily by its dielectric properties. The large difference between the dielectric constant of water and that of dry soil produces a strong dependence of the soil's dielectric constant on its moisture content. This dependence is effected by the texture of the soil because the water molecules close to the particle surface are tightly bound and do not contribute significantly to the dielectric properties. Since this surface area is a function of the particle size distribution (soil texture), being larger for clay soils with small particles, and smaller for sandy soils with larger particles; the dielectric properties will depend on soil texture. Laboratory measurements of the dielectric constant for soils are summarized. The dependence of the microwave emission on texture is demonstrated by measurements of brightness temperature from an aircraft platform for a wide range of soil textures. It is concluded that the effect of soil texture differences on the observed values can be normalized by expressing the soil moisture values as a percent field capacity for the soil.

Schmugge, T. J.

1980-01-01

195

Soil Particle Size Distribution Protocol  

Science.gov (United States)

The purpose of this resource is to sure the distribution of different sizes of soil particles in each horizon of a soil profile. Using dry, sieved soil from a horizon, students mix the soil with water and a dispersing solution to completely separate the particles from each other. Students shake the mixture to fully suspend the soil in the water. The soil particles are then allowed to settle out of suspension, and the specific gravity and temperature of the suspension are measured using a hydrometer and thermometer. These measurements are taken after 2 minutes and 24 hours.

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

2003-08-01

196

University of Florida: Soil Texture  

Science.gov (United States)

This University of Florida website educates the public about soil texture, which is the distribution of sizes of mineral particles found in soils. After learning the basics about soil separates, students and educators can learn about the USDA textural triangle and the characteristics of the twelve textural classes. Researchers can discover how to determine the correct soil texture in the field. The website addresses the important role soil textures play in the determination of proper land use activities and management practices. Visitors will also find a short discussion about other factors that affect the behavior and qualities of soils.

197

Lasagna trademark soil remediation  

International Nuclear Information System (INIS)

Lasagna trademark is an integrated, in situ remediation technology being developed which remediates soils and soil pore water contaminated with soluble organic compounds. Lasagna trademark is especially suited to sites with low permeability soils where electroosmosis can move water faster and more uniformly than hydraulic methods, with very low power consumption. The process uses electrokinetics to move contaminants in soil pore water into treatment zones where the contaminants can be captured and decomposed. Initial focus is on trichloroethylene (TCE), a major contaminant at many DOE and industrial sites. Both vertical and horizontal configurations have been conceptualized, but fieldwork to date is more advanced for the vertical configuration. Major features of the technology are electrodes energized by direct current, which causes water and soluble contaminants to move into or through the treatment layers and also heats the soil; treatment zones containing reagents that decompose the soluble organic contaminants or adsorb contaminants for immobilization or subsequent removal and disposal; and a water management system that recycles the water that accumulates at the cathode (high pH) back to the anode (low pH) for acid-base neutralization. Alternatively, electrode polarity can be reversed periodically to reverse electroosmotic flow and neutralize pH

198

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

199

Dryland soil microbial communities display spatial biogeographic patterns associated with soil depth and soil parent material  

Science.gov (United States)

Biological soil crusts (biocrusts) are common to drylands worldwide. We employed replicated, spatially nested sampling and 16S rRNA gene sequencing to describe the soil microbial communities in three soils derived from different parent material (sandstone, shale, and gypsum). For each soil type, two depths (biocrusts, 0–1 cm; below-crust soils, 2–5 cm) and two horizontal spatial scales (15 cm and 5 m) were sampled. In all three soils, Cyanobacteria and Proteobacteria demonstrated significantly higher relative abundance in the biocrusts, while Chloroflexi and Archaea were significantly enriched in the below-crust soils. Biomass and diversity of the communities in biocrusts or below-crust soils did not differ with soil type. However, biocrusts on gypsum soil harbored significantly larger populations of Actinobacteria and Proteobacteria and lower populations of Cyanobacteria. Numerically dominant operational taxonomic units (OTU; 97% sequence identity) in the biocrusts were conserved across the soil types, whereas two dominant OTUs in the below-crust sand and shale soils were not identified in the gypsum soil. The uniformity with which small-scale vertical community differences are maintained across larger horizontal spatial scales and soil types is a feature of dryland ecosystems that should be considered when designing management plans and determining the response of biocrusts to environmental disturbances.

Steven, Blaire; Gallegos-Graves, La Verne; Belnap, Jayne; Kuske, Cheryl R.

2013-01-01

200

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.

201

Predicting Radiocaesium Sorption with Soil Chemical Properties in Japanese Soils  

Energy Technology Data Exchange (ETDEWEB)

The soil-to-plant transfer mechanism of radiocaesium ({sup 137}Cs) in the Fukushima accident affected area is not fully understood. The sorption of {sup 137}Cs in soils holds a key to evaluating the variation of transfer of {sup 137}Cs to plant among different soil types. This study aims to investigate how differences in {sup 137}Cs adsorption in different soils can be explained by soil chemical and mineralogical properties. The Radiocaesium Interception Potential (RIP), a parameter for quantifying immediate {sup 137}Cs adsorption, and the soil texture were determined for 52 surface soils covering a wide range of texture classes collected from the area contaminated by the Fukushima accident. These soils include Andosols, Fluvisols, Gleysols, and Cambisols. In addition, we are currently performing analyses for other soil chemical properties (i.e. exchangeable cation, CEC, pH, organic matter content, etc) and for the properties affecting {sup 137}Cs sorption in soils (i.e. Frayed Edge Site capacity, K{sup +} and NH{sub 4}{sup +} selectivity, effect of wet-dry cycles, etc). The average RIP varied from 80 to 4300 mmol kg{sup -1} between soils. Contrary to what was found for temperate region soils by Absalom et al., the RIP (log(RIP)) and soil clay content were not significantly correlated (R2= 0.066). These initial results seem to indicate that the {sup 137}Cs sorption is affected by the clay mineralogy in soils. We postulate that by considering also the differences in clay K content, the relationship will improve since the frayed edges are formed at high K content in the clay. This knowledge could improve the prediction of RIP for different Japanese soil groups. Further analysis of the data will explore the relationship between RIP and other soil chemical properties. In our study, we will take specific note of Andosols (range of average RIP from 80 to 2400 mmol kg{sup -1}), typical soils in Japan originated from volcanic ash. It is expected that soil properties ruling the {sup 137}Cs sorption for Japanese Andosols will differ compared to other temperate mineral soils, for which most {sup 137}Cs transfer studies have been performed after the Chernobyl accident. We start by investigating the role of amorphous Al and Fe in {sup 137}Cs sorption. We believe that our findings could contribute to improved predictions of soil-to-plant transfer in Japanese soils and to the development of feasible countermeasures to reduce {sup 137}Cs transfer to plants for different soil-crop combinations in Japan. (authors)

Uematsu, Shinichiro [SCK.CEN, Belgian Nuclear Research Centre, Boeretang 200, B-2400 Mol (Belgium); Faculty of Bioscience Engineering, Katholieke Universiteit Leuven, Kasteelpark Arenberg 20, B-3001 Leuven (Belgium); Van Hees, May; Wannijn, Jean; Sweeck, Lieve; Vandenhove, Hildegarde [SCK.CEN, Belgian Nuclear Research Centre, Boeretang 200, B-2400 Mol (Belgium); Smolders, Erik [Faculty of Bioscience Engineering, Katholieke Universiteit Leuven, Kasteelpark Arenberg 20, B-3001 Leuven (Belgium)

2014-07-01

202

Predicting Radiocaesium Sorption with Soil Chemical Properties in Japanese Soils  

International Nuclear Information System (INIS)

The soil-to-plant transfer mechanism of radiocaesium (137Cs) in the Fukushima accident affected area is not fully understood. The sorption of 137Cs in soils holds a key to evaluating the variation of transfer of 137Cs to plant among different soil types. This study aims to investigate how differences in 137Cs adsorption in different soils can be explained by soil chemical and mineralogical properties. The Radiocaesium Interception Potential (RIP), a parameter for quantifying immediate 137Cs adsorption, and the soil texture were determined for 52 surface soils covering a wide range of texture classes collected from the area contaminated by the Fukushima accident. These soils include Andosols, Fluvisols, Gleysols, and Cambisols. In addition, we are currently performing analyses for other soil chemical properties (i.e. exchangeable cation, CEC, pH, organic matter content, etc) and for the properties affecting 137Cs sorption in soils (i.e. Frayed Edge Site capacity, K+ and NH4+ selectivity, effect of wet-dry cycles, etc). The average RIP varied from 80 to 4300 mmol kg-1 between soils. Contrary to what was found for temperate region soils by Absalom et al., the RIP (log(RIP)) and soil clay content were not significantly correlated (R2= 0.066). These initial results seem to indicate that the 137Cs sorption is affected by the clay mineralogy in soils. We postulate that by considering also the differences in clay K content, the relationship will improve since the frayed edges are formed at high K content in the clay. This knowledge could improve the prediction of RIP for different Japanese soil groups. Further analysis of the data will explore the relationship between RIP and other soil chemical properties. In our study, we will take specific note of Andosols (range of average RIP from 80 to 2400 mmol kg-1), typical soils in Japan originated from volcanic ash. It is expected that soil properties ruling the 137Cs sorption for Japanese Andosols will differ compared to other temperate mineral soils, for which most 137Cs transfer studies have been performed after the Chernobyl accident. We start by investigating the role of amorphous Al and Fe in 137Cs sorption. We believe that our findings could contribute to improved predictions of soil-to-plant transfer in Japanese soils and to the development of feasible countermeasures to reduce 137Cs transfer to plants for different soil-crop combinations in Japan. (authors)

203

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

204

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

2006-07-01

205

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

206

Soil fungi as indicators of pesticide soil pollution  

OpenAIRE

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 fung...

Mandi? Leka; ?uki? Dragutin; ?or?evi? Snežana

2005-01-01

207

Soil gas radon response to environmental and soil physics variables  

International Nuclear Information System (INIS)

During the last three years a field study of soil gas radon activities conducted at Poamoho, Oahu, has shown that the primary environmental variables that control radon transport in shallow tropical soils are synoptic and diurnal barometric pressure changes and soil moisture levels. Barometric pressure changes drive advective transport and mixing of soil gas with atmospheric air; soil moisture appears to control soil porosity and permeability to enhance or inhibit advective and diffusive radon transport. An advective barrier test/control experiment has shown that advective exchange of soil gas and air may account for a substantial proportion of the radon loss from shallow soils but does not significantly affect radon activities at depths greater than 2.3 m. An irrigation test/control experiment also suggests that, at soil moisture levels approaching field capacity, saturation of soil macroporosity can halt all advective transport of radon and limit diffusive mobility to that occurring in the liquid phase. The results of the authors field study have been used to further refine and extend a numerical model, RN3D, that has been developed by Pacific Northwest Laboratories to simulate subsurface transport of radon. The field data have allowed them to accurately simulate the steady state soil gas radon profile at their field site and to track transient radon activities under the influence of barometric pressure changes and in response to changes in soil permeability that rese 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

208

Analysis of soil variability measured with a soil strength sensor  

OpenAIRE

In the context of precision agriculture, the knowledge of soil strength variability at the field scale may be useful for improving site-specific tillage. Moreover, rapid and accurate sensing methods for soil physical properties determination would favourably replace labour intensive, time-consuming and expensive soil sampling and analysis. This study aims at validating conclusions of a previous study which was conducted to develop a soil strength in field conditions. The coupled acquisition o...

Hanquet, Bernard; Sirjacobs, Damien; Destain, Marie-france; Frankinet, Marc; Verbrugge, Jean-claude

2004-01-01

209

Radon mitigation in soils  

International Nuclear Information System (INIS)

Radon is produced in soil by radium decay, Ra-226 for radon (Rn-222) and Ra-224 for thoron (Rn-220). The radium content is about 40 Bq.kg-1 in crustal rocks and soils, 70 Bq.kg-1 in granite and only about 8 Bq.kg-1 in limestone. Being the heaviest gas in atmosphere, radon presents high concentration at surface and it is accumulating in closed or poorly ventilated places, both in underground cavities (caves or mines) and in dwelling. In comparison with the average radon concentration in atmospheric air of 8 Bq.m-3, the average indoor radon concentration reaches 10-100 Bq.m-3. International statistics indicate that radon contribution on natural irradiation is about 60%. The main sources of indoor radon are: radium content of the soil and of the concretes, water supply and natural gases

210

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

211

Soil texture classification algorithm using RGB characteristics of soil images  

Science.gov (United States)

Soil texture has an important influence on agriculture, affecting crop selection, movement of nutrients and water, soil electrical conductivity, and crop growth. Soil texture has traditionally been determined in the laboratory using pipette and hydrometer methods that require a considerable amount o...

212

Occurrence of entomopathogenic fungi in arable soil and meadow soil  

OpenAIRE

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; Cezary Tkaczyk; Ludwik Zasada

1992-01-01

213

Constructive Similarity of Soils.  

Czech Academy of Sciences Publication Activity Database

Singapore : Design, CRC a iTEK CMS Web solutions, 2012 - (Phoon, K.; Beer, M.; Quek, S.; Pang, S.), s. 206-211 ISBN 978-981-07-2218-0. [APS on Structural Reliability and Its Application – Sustainable Civil Infrastructures /5./. Singapore (SG), 23.05.2012-25.05.2012] Grant ostatní: GA ?R(CZ) GAP105/11/1160 Institutional support: RVO:68378297 Keywords : model similarity * database of soil properties * soil similarity characteristic * statistical analysis * ultimate limit states Subject RIV: JM - Building Engineering

Koudelka, Petr

214

Soil and ground cover  

International Nuclear Information System (INIS)

The monitoring programmes set up in accordance with the directives for the surveillance of effluents from nuclear installations oblige operators of such installations to take samples of vegetation (grass) and soil twice a year at the least favourable place in the industrial plant's environment, and at a reference site, for radioactivity monitoring by gamma spectroscopy. In addition, the samples are to be examined for their Sr-90 content. Data recorded over the years show that nuclear facilities do not significantly contribute to soil and vegetation contamination with Sr-90 or Cs-137. The directives require regular interlaboratory comparisons, which are coordinated by the directing centre at Kiel. (DG)

215

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

216

Soil mechanics experiment  

Science.gov (United States)

The Apollo 15 soil-mechanics experiment has offered greater opportunity for study of the mechanical properties of the lunar soil than previous missions, not only because of the extended lunar-surface stay time and enhanced mobility provided by the lunar roving vehicle (rover), but also because four new data sources were available for the first time. These sources were: (1) the self-recording penetrometer (SRP), (2) new, larger diameter, thin-walled core tubes, (3) the rover, and (4) the Apollo lunar-surface drill (ALSD). These data sources have provided the best bases for quantitative analyses thus far available in the Apollo Program.

Mitchell, J. K.; Bromwell, L. G.; Carrier, W. D., III; Costes, N. C.; Houston, W. N.; Scott, R. F.

1972-01-01

217

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.

Colin Robins

218

Soil contamination studies  

International Nuclear Information System (INIS)

The objective of this project was to develop a quick screening method that accurately identifies and quantifies the amount of alpha-emitting radionuclides in infinitely-thick soil samples using a Frisch grid ionization chamber. An additional objective of the work was to provide the US Department of Energy, Nevada Operations Office and its contractors with information on the theoretical and actual measured results of atmospheric testing contamination of soil and water at the Nevada Test Site through a comprehensive search of existing literature

219

Elementary GLOBE: Soil Treasure Hunt  

Science.gov (United States)

A learning activity for the Scoop on Soils book in the Elementary GLOBE Series. Students will make predictions about what they think they will find in a sample of soil. They will investigate the sample and sort out the various items they find. Next they will spend time outside observing one or more sites to see what they find in the soil. After recording and sharing their observations they will create their own stories about the things they found in the soil. The purpose of the activity is to learn about natural things commonly found in soil and how these things impact how the soil looks and feels as well as to introduce students to the concept of decomposition. After completing this activity, students will know about various things found in soil including rocks, critters, roots, and other organic material. They will also understand that animals and microorganisms aid in the decomposition process that contributes organic materials to soils.

2008-12-01

220

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)

221

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

222

Soil health in agricultural systems  

OpenAIRE

Soil health is presented as an integrative property that reflects the capacity of soil to respond to agricultural intervention, so that it continues to support both the agricultural production and the provision of other ecosystem services. The major challenge within sustainable soil management is to conserve ecosystem service delivery while optimizing agricultural yields. It is proposed that soil health is dependent on the maintenance of four major functions: carbon transformations; nutrient ...

Kibblewhite, M. G.; Ritz, K.; Swift, M. J.

2007-01-01

223

Sustainable Soil Water Management Systems  

OpenAIRE

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

224

Soil carbon determination by thermogravimetrics  

OpenAIRE

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...

Robert Pallasser; Budiman Minasny; Mcbratney, Alex B.

2013-01-01

225

Soil, a sponge for pollutants  

OpenAIRE

This preface of the special issue entitled "Soil Pollutants" (Analusis Magazine 25, M16-M72, 1997) highlights major basic and applied issues about the sources and fate of organic, mineral and radioactive pollutants in soils. Soils have long been considered as a closed and inert medium where wastes can be dumped without impact on living organisms. This is false and we know now that soils play a vital role in ecosystems. Pollution sources are diverse and numerous. Toxic compounds are either of ...

Lichtfouse, Eric

1997-01-01

226

"PRACTICAL PHYTOEXTRACTION OF SOIL CD"  

Science.gov (United States)

Selection of appropriate methods for remediation of soil metals requires careful evaluation of whether the soil contaminant is sufficiently bioavailable or phytoavailable to require remediation. Extensive study of soil Cd risk has recently demonstrated that the high prevalence of renal tubular dysfu...

227

ACTUAL STAGE IN SOIL REMEDIATION  

OpenAIRE

The article describes a few theoretical aspects concerning soil depollution processes. Techniques for the treatment of polluted soils have as an objective the destruction, elimination or immobilization of pollutants. The choice of the soil depollution technique or of the treatment method/type depends on the intrinsic characteristics of those techniques (on performance, installation), and on constraints specific to the site.

GABRIEL LAZAR; ALEXANDRA-DANA CHITIMUS; VALENTIN NEDEFF

2011-01-01

228

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

229

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 ...

230

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 ...

231

Cadmium absorption inhibitors for soil  

Energy Technology Data Exchange (ETDEWEB)

Cadmium absorption by soil is one cause of soil pollution. Cadmium adsorption inhibitors were prepared by mixing alginic acid which contained brown algae (Ascophyllum nodosum) and an inorganic material, shell fossils. This mixture was highly effective in preventing cadmium absorption by the soil.

Kitamura, S.

1974-05-25

232

Soil Erosion Control After Wildfire  

Science.gov (United States)

The potential for severe soil erosion is a consequence of wildfire because as a fire burns it destroys important plant material and the litter layer that stabilizes soil and slows water movement after severe rainstorms. This information sheet discusses how intense heat from fire can make soils hydrophobic, or water repellent, and identifies the actions landowners can take to minimize erosion after a fire.

233

Soil threats and soil protection: the role of biotechnology  

Energy Technology Data Exchange (ETDEWEB)

The concept of soil conservation/soil protection in its wider sense has undergone important changes through history. Perceptions of soil as a crucial base of life in ancient cultures progressively evolved to a more pragmatic vision, with close connection to food production for survival. For centuries, agrarian production and the provision of food for humankind remained the main and crucial vision of the interaction of societies with soil. However, there are also some other new and important concepts related to soil which have progressively developed. (Author)

Rubio, J. L.

2009-07-01

234

Soil threats and soil protection: the role of biotechnology  

International Nuclear Information System (INIS)

The concept of soil conservation/soil protection in its wider sense has undergone important changes through history. Perceptions of soil as a crucial base of life in ancient cultures progressively evolved to a more pragmatic vision, with close connection to food production for survival. For centuries, agrarian production and the provision of food for humankind remained the main and crucial vision of the interaction of societies with soil. However, there are also some other new and important concepts related to soil which have progressively developed. (Author)

235

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

236

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.

237

Exploring Soil Ecosystems.  

Science.gov (United States)

Describes a soil lab that can be performed with a minimum of equipment and time, utilizing a lawn, field, or woodlot. Students dig a 1-meter-deep pit and observe the litter and humus layers where most microbial and fungal decomposition occurs. Describes comparing different locations by pH level and concentration of potassium, phosphorous, and…

Finley, Deborah R.

1991-01-01

238

Soil and Sediment Erosion  

Science.gov (United States)

This brief article discusses the effect of soil and sediment erosion and its significance in social and economic aspects. The methods of measuring erosion and knowledge of past erosion rates are also briefly discussed to use as a predictor of future erosion rates.

239

Soil and vegetation  

International Nuclear Information System (INIS)

Surface soil and vegetation samples are collected annually from a number of locations for the purpose of measuring the radionuclide concentrations from worldwide fallout, natural causes, and any cumulative buildup of radionuclides from Hanford operations. Radionuclide concentrations in samples taken during 1980 were similar to previous years. No obvious geographical radionuclide distribution pattern was observed in the 1980 samples

240

Wood-soil interactions in soil bioengineering slope stabilization works  

Directory of Open Access Journals (Sweden)

Full Text Available In this work we propose the use of soil quality indicators with the aim of assessing the environmental impact of soil bioengineering works. This study was carried out in central Italy where soil bioengineering slope stabilization works were established using chestnut wood. In particular the goal of this study was to determine the occurrence of a wood-effect, that is changes of soil properties due to the presence of decomposing logs in two sites characterized by different time span since works setting up. The presence of the logs did not affect soil physico-chemical properties. Conversely, soil biochemical properties such as soil microbial biomass, basal and cumulative respiration activities as well as microbial indexes, were influenced by the presence of the logs confirming the role of these bioindicators as early predictors of changes occurring in soil. Although a general positive trend was observed for the biochemical properties at both sites with respect to the control soils, significant differences were recorded mainly at the site where works were established six years before soil sampling. Soil bioengineering slope stabilization works establish a positive feed-back which ultimately can benefit plants; in fact the increase in microbial mineralization activity can enhance nutrient cycling and thus promote adequate growth conditions for the plant cuttings used in the wooden-work.

Moscatelli MC

2009-10-01

241

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

242

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 samples (Haber-Pohlmeier et al. 2010). Third, relaxometric information forms the basis of understanding magnetic resonance imaging (MRI) results. The general difficulty of imaging in soils are the inherent fast T2 relaxation times due to i) the small pore sizes, ii) presence of paramagnetic ions in the solid matrix, and iii) diffusion in internal gradients. The last point is important, since echo times can not set shorter than about 1ms for imaging purposes. The way out is either the usage of low fields for imaging in soils or special ultra-short pulse sequences, which do not create echoes. In this presentation we will give examples on conventional imaging of macropore fluxes in soil cores (Haber-Pohlmeier et al. 2010), and the combination with relaxometric imaging, as well as the advantages and drawbacks of 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

243

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

244

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

245

Acid Rain Experiments: Soil Buffering  

Science.gov (United States)

This experiment will help students understand that soil sometimes contains substances, like limestone, that buffer acids or bases, and that some salts in soil may also act as buffers. They will collect soil samples from their lawn, garden, or school and look for buffering effects by observing the pH change of an acid mixture poured through the samples. If the water collected from the sample is less acidic than the original mixture, then the soil is buffering some of the acid. If it does not change, then the soil may not be capable of buffering acids.

246

Soil Erosion and Agricultural Sustainability  

Science.gov (United States)

Data drawn from a global compilation of studies support the long articulated contention that erosion rates from conventionally plowed agricultural fields greatly exceed rates of soil production, erosion under native vegetation, and long-term geological erosion. Whereas data compiled from around the world show that soil erosion under conventional agriculture exceeds both rates of soil production and geological erosion rates by up to several orders of magnitude, similar global distributions of soil production and geological erosion rates suggest an approximate balance. Net soil erosion rates in conventionally plowed fields on the order of 1 mm/yr can erode typical hillslope soil profiles over centuries to millennia, time-scales comparable to the longevity of major civilizations. Well-documented episodes of soil loss associated with agricultural activities date back to the introduction of erosive agricultural methods in regions around the world, and stratigraphic records of accelerated anthropogenic soil erosion have been recovered from lake, fluvial, and colluvial stratigraphy, as well as truncation of soil stratigraphy (such as truncated A horizons). A broad convergence in the results from studies based on various approaches employed to study ancient soil loss and rates of downstream sedimentation implies that widespread soil loss has accompanied human agricultural intensification in examples drawn from around the world. While a broad range of factors, including climate variability and society-specific social and economic contexts — such as wars or colonial relationships — all naturally influence the longevity of human societies, the ongoing loss of topsoil inferred from studies of soil erosion rates in conventional agricultural systems has obvious long-term implications for agricultural sustainability. Consequently, modern agriculture — and therefore global society — faces a fundamental question over the upcoming centuries. Can an agricultural system capable of feeding a growing population safeguard both soil fertility and the soil itself? Although the experiences of past societies provide ample historical basis for concern about the long-term prospects for soil conservation, data compiled from recent studies indicate that no-till farming could reduce erosion to levels close to soil production rates. Consequently, agricultural production need not necessarily come at the expense of either soil fertility or the soil itself, even if recent proposals to rely on conventionally grown corn for biofuels exemplify how short-term social and economic trade-offs can de-prioritize soil conservation. Like the issues of climate change and loss of biodiversity, the ongoing global degradation and loss of soil presents a fundamental social challenge in which the slow pace of environmental change counter-intuitively makes solutions all the more difficult to adopt.

Montgomery, D. R.

2009-04-01

247

Remote assessment of soil moisture  

International Nuclear Information System (INIS)

Soil moisture can be estimated in the upper few centimeters of the soil profile by three separate remote sensing techniques. The simplest and least costly method uses the ratio of reflected to incoming solar radiation (albedo). Just as simple, but more costly for equipment, is the use of emitted thermal radiation. Surface soil temperature and air temperature are the only measurements required to estimate water content near the soil surface. Both active and passive microwave techniques can be used to infer soil water content, potentially to depths of 10 cm; however, they require more sophisticated and bulky equipment than the other two methods. (author)

248

Permafrost soils and carbon cycling  

Science.gov (United States)

Knowledge of soils in the permafrost region has advanced immensely in recent decades, despite the remoteness and inaccessibility of most of the region and the sampling limitations posed by the severe environment. These efforts significantly increased estimates of the amount of organic carbon stored in permafrost-region soils and improved understanding of how pedogenic processes unique to permafrost environments built enormous organic carbon stocks during the Quaternary. This knowledge has also called attention to the importance of permafrost-affected soils to the global carbon cycle and the potential vulnerability of the region's soil organic carbon (SOC) stocks to changing climatic conditions. In this review, we briefly introduce the permafrost characteristics, ice structures, and cryopedogenic processes that shape the development of permafrost-affected soils, and discuss their effects on soil structures and on organic matter distributions within the soil profile. We then examine the quantity of organic carbon stored in permafrost-region soils, as well as the characteristics, intrinsic decomposability, and potential vulnerability of this organic carbon to permafrost thaw under a warming climate. Overall, frozen conditions and cryopedogenic processes, such as cryoturbation, have slowed decomposition and enhanced the sequestration of organic carbon in permafrost-affected soils over millennial timescales. Due to the low temperatures, the organic matter in permafrost soils is often less humified than in more temperate soils, making some portion of this stored organic carbon relatively vulnerable to mineralization upon thawing of permafrost.

Ping, C. L.; Jastrow, J. D.; Jorgenson, M. T.; Michaelson, G. J.; Shur, Y. L.

2015-02-01

249

NCRP soil contamination task group  

International Nuclear Information System (INIS)

The National Council of Radiation Protection and Measurements (NCRP) has recently established a Task Group on Soil Contamination to describe and evaluate the migration pathways and modes of radiation exposure that can potentially arise due to radioactive contamination of soil. The purpose of this paper is to describe the scientific principles for evaluation of soil contamination which can be used as a basis for derivation of soil contamination limits for specific situations. This paper describes scenarios that can lead to soil contamination, important characteristics of soil contamination, the subsequent migration pathways and exposure modes, and the application of principles in the report in deriving soil contamination limits. The migration pathways and exposure modes discussed in this paper include: direct radiation exposure; and exhalation of gases

250

Communicating soil property variability in heterogeneous soil mapping units  

Science.gov (United States)

Soil properties and classes can change over very short distances. For the purpose of scale, clarity and field sampling density, soil maps in England and Wales commonly use mapping units which are groupings of taxonomic soil series, commonly found in association with each other in the landscape. These mixed units (Soil Associations), typically contain between 3 and 7 soil series with physical or chemical properties, which can vary across the mapping unit, or may be relatively homogeneous. The degree of variation is not constant between soil properties, for instance, pH may be relatively constant, but volumetric shrinkage potential may be highly variable. Over the past ten years, the number of users of GIS soil property maps has dramatically increased, yet the vast majority of these users do not have a soil or geoscience background. They are instead practitioners in specific industries. As a result, new techniques have been developed to communicate the variation in maps of soil properties to a non-expert audience. GIS data structures allow more flexibility in the reporting of uncertainty or variation in soil mapping units than paper-based maps. Some properties are categorical, others continuous. In England and Wales, the national and regional memberships of soil associations are available, with areal percentages of the comprising soil series being estimated for each association by a combination of expert judgment and field observations. Membership at a local scale can vary considerably from the national average. When summarizing across a whole map unit, for continuous variables, rarely is it appropriate to provide a mean value, or even a weighted average based on membership percentage of the association. Such approaches can make a nonsense of wide-ranging data. For instance a soil association comprising soil series with highly different percentages of sand, silt and clay may result in a 'loamy' mean soil texture which is not reflective of any of the comprising soils. For categorical data, the choice of the property of the spatially dominant soil series may provide the 'most likely' answer, but this may not be the most helpful answer for the end user. Additionally, when aggregating to select the dominant property or class, rather than the dominant taxonomic soil series, it is not uncommon for the 'dominant' class to change. One example of our new approach is to communicate the attributes of the soil associations on the basis of the worst-case scenario at various confidence levels, based on the percentage of the soil series of the association. As an example, when soil maps are used to help underwriters understand the vulnerability of an area to soil related subsidence, the maximum subsidence rating can be chosen from soils which comprise, for example, more than 5% or more than 30% of the soil association in question. Developing an understanding of end-user requirements allows optimization of soil datasets to suit their needs, and encourages engagement between soil scientists and industry.

Farewell, Timothy

2014-05-01

251

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)

252

Soil Carbon Sequestration in India  

Energy Technology Data Exchange (ETDEWEB)

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.

Lal, R. [Carbon Management and Sequestration Center, The Ohio State University, 2021 Coffey Road, Columbus, OH 43210 (United States)

2004-07-01

253

Ephemeral gully: soil control factors  

Science.gov (United States)

Soil erosion on hillslopes has been divided traditionally into sheet, rill, and (ephemeral) gully erosion. In sheet erosion, a relatively shallow overland flow acts on a hillslope and removes sediment particles uniformly from the land surface. Usually, rill erosion occur in uncertain points within sloping surfaces, whereas gullies occur in more specific places in the landscapes, i.e., within topographic swales or hollows. So that, current models for prediction of (ephemeral) gully initiation and development rely mainly on topographic factors while soil conditions are almost neglected. However, the assessment of the erodibility of soil materials is essential for analyzing and properly modeling gully erosion. But, despite the wealth of studies to characterize soil vulnerability to (gully) erosion, a universal approach is still lacking. This is due to the complexity of soil conditions and erosion phenomenon and their interactions. A useful and feasible soil characterization for gully erosion prediction at large scale should be based on simple, quick, repeatable and relatively inexpensive tests to perform. This work proposes a methodology for conducting simple tests in the field and laboratory to detect soil conditions prone to gully initiation. This approach for assessing soil erodibility includes the use of vane shear apparatus, penetrometers and a mini-rain simulator as well as some current (modified) laboratory tests for assessing soil crustability and erodibility. A pool of simple soil variables to assess soils prone to gully development is proposed. Among the main variables we have the granulometric composition of the top soil (textural fractions and gravel), organic matter content, soil cohesiveness and relative sensitivity of topsoils for crusting. Our finding may be particularly useful for erosion modelling when gully initiation and development do not largely rely on topographic features but in soil conditions.

Ollobarren, Paul; Giménez, Rafael; Ángel Campo, Miguel; Casalí, Javier

2014-05-01

254

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

255

Discovering the essence of soil  

Science.gov (United States)

Science, and what it can learn, is constrained by its paradigms and premises. Similarly, teaching and what topics can be addressed are constrained by the paradigms and premises of the subject matter. Modern soil science is founded on the five-factor model of Dokuchaev and Jenny. Combined with Retallack's universal definition of soil as geologic detritus affected by weathering and/or biology, modern soil science emphasizes a descriptive rather than an interpretive approach. Modern soil science however, emerged from the study of plants and the need to improve crop yields in the face of chronic and wide spread famine in Europe. In order to teach that dirt is fascinating we must first see soils in their own right, understand their behavior and expand soil science towards an interpretive approach rather than limited as a descriptive one. Following the advice of James Hutton given over two centuries ago, I look at soils from a physiological perspective. Digestive processes are mechanical and chemical weathering, the resulting constituents reformed into new soil constituents (e.g. clay and humus), translocated to different regions of the soil body to serve other physiological processes (e.g. lamellae, argillic and stone-line horizons), or eliminated as wastes (e.g. leachates and evolved gasses). Respiration is described by the ongoing and diurnal exchange of gasses between the soil and its environment. Circulatory processes are evident in soil pore space, drainage capacity and capillary capability. Reproduction of soil is evident at two different scales: the growth of clay crystals (with their capacity for mutation) and repair of disturbed areas such as result from the various pedo-perturbations. The interactions between biotic and abiotic soil components provide examples of both neurological and endocrine systems in soil physiology. Through this change in perspective, both biotic and abiotic soil processes become evident, providing insight into the possible behavior of ancient prebiotic soils. Furthermore, the physiological approach sheds light on the emergence of new soil components (e.g. spodic horizons) as ancient prebiotic soils adapt to a plethora of biotic carbon compounds. Other emergent soil properties and behaviors can be linked to the kinds, frequencies, order and intensities of various ubiquitous pedo-perturbations.

Frink, D.

2012-04-01

256

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

257

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

258

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)

259

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

260

Fate and transport of chromium through soil  

International Nuclear Information System (INIS)

Chromium chemistry relevant to the problem facing state of New Jersey (Usa) was examined. Transport of chromium through soil depends on its chemical forms. Transformation of chromium within bulk of soil depends on soil constituents, soil condition, such as pH, Eh and organic compounds applied onto soil or present in soil. Total chromium in soil can be determined. Speciation of chromium based on ionization, hydrolysis, complex formation, redox reactions and adsorption is predicted using MINIQ program

261

Pneumatic soil removal tool  

International Nuclear Information System (INIS)

A soil removal tool is provided for removing radioactive soil, rock and other debris from the bottom of an excavation, while permitting the operator to be located outside of a containment for that excavation. The tool includes a fixed jaw, secured to one end of an elongate pipe, which cooperates with a movable jaw pivotably mounted on the pipe. Movement of the movable jaw is controlled by a pneumatic cylinder mounted on the pipe. The actuator rod of the pneumatic cylinder is connected to a collar which is slidably mounted on the pipe and forms part of the pivotable mounting assembly for the movable jaw. Air is supplied to the pneumatic cylinder through a handle connected to the pipe, under the control of an actuator valve mounted on the handle, to provide movement of the movable jaw. 3 figs

262

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

263

Plant diversity increases soil microbial activity and soil carbon storage.  

Science.gov (United States)

Plant diversity strongly influences ecosystem functions and services, such as soil carbon storage. However, the mechanisms underlying the positive plant diversity effects on soil carbon storage are poorly understood. We explored this relationship using long-term data from a grassland biodiversity experiment (The Jena Experiment) and radiocarbon ((14)C) modelling. Here we show that higher plant diversity increases rhizosphere carbon inputs into the microbial community resulting in both increased microbial activity and carbon storage. Increases in soil carbon were related to the enhanced accumulation of recently fixed carbon in high-diversity plots, while plant diversity had less pronounced effects on the decomposition rate of existing carbon. The present study shows that elevated carbon storage at high plant diversity is a direct function of the soil microbial community, indicating that the increase in carbon storage is mainly limited by the integration of new carbon into soil and less by the decomposition of existing soil carbon. PMID:25848862

Lange, Markus; Eisenhauer, Nico; Sierra, Carlos A; Bessler, Holger; Engels, Christoph; Griffiths, Robert I; Mellado-Vázquez, Perla G; Malik, Ashish A; Roy, Jacques; Scheu, Stefan; Steinbeiss, Sibylle; Thomson, Bruce C; Trumbore, Susan E; Gleixner, Gerd

2015-01-01

264

Fallout fractionation in silicate soils  

International Nuclear Information System (INIS)

The existing models for testing radiochemical fractionation in nuclear weapon debris are discussed and compared. A method which extends the existing theory for the case of surface bursts over silicate soils is developed and validated with weapons test data. There is evidence that fission product absorption by soil and weapon debris is diffusion controlled. There is also evidence that there are two superimposed distributions of soil particles. A portion of the soil is fully vaporized along with the weapon debris while some soil is merely melted. As the fireball cools, the refractory fission products will be absorbed by this liquid material. After the fireball has cooled below the soil solidification temperature, the remaining fission products can be adsorbed onto any available surfaces. Any soil which entered the fireball at the soil solidification time or later will also adsorb fission products. Test data and other evidence indicate that the distributions of melted and unmelted soil particles have different modes. This model uses Henry's Law to find surface concentrations. It then uses diffusion theory to transport the fission products into the particles. In addition, it allows for injection of unmelted material near the time of soil solidification. The results of the research indicate that in standard DELFIC calculations too much activity is carried in the larger particles and too little in the smaller particles

265

Soil mechanics: breaking ground.  

Science.gov (United States)

In soil mechanics, student's models are classified as simple models that teach us unexplained elements of behaviour; an example is the Cam clay constitutive models of critical state soil mechanics (CSSM). 'Engineer's models' are models that elaborate the theory to fit more behavioural trends; this is usually done by adding fitting parameters to the student's models. Can currently unexplained behavioural trends of soil be explained without adding fitting parameters to CSSM models, by developing alternative student's models based on modern theories?Here I apply an alternative theory to CSSM, called 'breakage mechanics', and develop a simple student's model for sand. Its unique and distinctive feature is the use of an energy balance equation that connects grain size reduction to consumption of energy, which enables us to predict how grain size distribution (gsd) evolves-an unprecedented capability in constitutive modelling. With only four parameters, the model is physically clarifying what CSSM cannot for sand: the dependency of yielding and critical state on the initial gsd and void ratio. PMID:17855225

Einav, Itai

2007-12-15

266

Radionuclide migration in soils  

International Nuclear Information System (INIS)

Unplanned releases from a nuclear installation - e.g., leakage from a storage tank or other incident - can result in the escape of contaminants such as U, Pu, Cs, Sr, T etc. Nuclide transport through the ground is governed by characteristics of the subsurface hydrology and the specific nuclides under consideration. Unsaturated soil layers result in a transport rate so low as to negligible. Radionuclides reaching the ground water are assumed to endanger human life because of potential uncontrolled ingestion. The most dangerous nuclides are long-lived and not absorbed, or very poorly absorbed, in the soil. During migration of nuclides through saturated soil layers, the concentration can be reduced by dilution. Preliminary results indicate that tritium is spread with ground water velocity. Its concentration can be reduced only by diffusion, dispersion and radioactive decay. Alpha-emitters are strongly retained velocities of alpha-emitters are approximately one thousandth (10-3) that of T. Transport velocities of Cs and Sr are approximately one hundreth (10-2) and one tenth (10-1) that of T respectively. (orig./HP)

267

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

268

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

269

EFFECT OF SOIL MOISTURE, SOIL DENSITY, AND CONE PENETROMETER MATERIAL ON FINITE ELEMENT PREDICTION OF SOIL HARDPAN DEPTH  

Science.gov (United States)

An accurate soil hardpan determination is important for maximum precision tillage performance. Soil cone penetrometer data are often analyzed to predict soil hardpan depths. The prediction in layered soils may be limited due to the complexity of soil reaction to cone penetration. An axisymmetric fin...

270

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)

271

Copper activity in soil solutions of calcareous soils  

International Nuclear Information System (INIS)

Copper partitioning was studied in seven calcareous soils at moisture content corresponding to 1.2 times the field moisture content (soil water potential 7.84 J kg-1). Copper retention was accompanied by the release in soil solution of Ca2+, Mg2+, Na+, and H+, and the total amount of these cations released was 0.8 to 1.09 times the amount of Cu sorbed (molc:molc). The relationships between Cu activity and pH, and the balance of cations in soils correspond with the surface precipitation of CuCO3 as the main mechanism of Cu retention. The values of ion activity product of surface precipitate were close for all studied soils with the average log(IAPCuCO3) = -15.51. The relationship between copper activity in soil solutions and soil properties is well fit by a regression relating pCu (-log copper ion activity) with soil ph, total Cu, and carbonate content. - Copper activity in contaminated calcareous soils is controlled by surface precipitated CuCO3 with log ion activity product of -15.51

272

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

273

Elementary GLOBE: Getting to Know Soil  

Science.gov (United States)

A learning activity for the Scoop on Soils book in the Elementary GLOBE Series. Each student will make predictions about the properties of various soil samples. Then they will examine several types of soils and record their observations. Next, they will learn about soil profiles and horizons by both examining a soil sample in a jar and by creating a soil profile flip chart. The purpose of the activity is to provide the opportunity for students to ask questions and make observations about soil and introduce students to the properties of soil and to the concept of soil profiles and horizons. After completing this activity, students will know about soil's different properties and about soil profiles. Students will know that soils have different properties including texture, color, and size. They will know that soil forms layers based on these properties.

2008-12-01

274

Part II. Radioactivity in soils  

International Nuclear Information System (INIS)

The 90Sr and 137Cs levels in different places in Slovakia were studied with regard to the effect of the type of soils on radionuclide bonds, to the presence of some non-radioactive elements, penetration to deep soil layers, fertilization and ion exchange capacity of the soils. 90Sr was determined via exchangeability with calcium measured in soil extract. 137Cs was determined by its exchangeability with potassium. Also determined were concentrations of Ca, K, P, SiO2, 90Sr, and 137Cs in 0 to 5 cm and 5 to 15 cm layers of cultivated soil. For the period of 1962 to 1975, the cumulative content was determined for 90Sr in range of 94 to 332 pCi/kg and for 137Cs in a range of 122 to 415 pCi/kg. The highest levels of both radionuclides were found in forest soils. (J.P.)

275

Mobility of zinc in soils  

International Nuclear Information System (INIS)

The effects of organic matter, CaCO3, N and P at different levels on the mobility of surface applied zinc under saturated moisture condition were studied in the laboratory lysimeters with 65Zn-labelled ZnSO4 in alluvial sand, sandy loam and medium black soils. Results indicate that the surface applied labelled zinc moved downward in soil columns irrespective of soil texture, but the movement was restricted by the application of N, P, organic matter and CaCO3. About 22 percent of the surface applied Zn was lost during leaching from 30 cm deep soil column in alluvial sand, whereas the loss was less than 1 percent in sandy loam and clay soils. Most of the applied zinc remained within the first 15 cm depth of the soil columns in all cases. (author)

276

Stochastic Modeling of Soil Salinity  

CERN Document Server

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 solutions provide insight on the interplay of the main soil, plant and climate parameters responsible for long-term soil salinization. In particular, they show the existence of two distinct regimes, one where the mean salt mass remains nearly constant (or decreases) with increasing rainfall frequency, and another where mean salt content increases markedly with increasing rainfall frequency. As a result, relatively small reductions of rainfall in drier climates may entail dramatic shifts in long-term soil salinization trend...

Suweis, S; Van der Zee, S E A T M; Daly, E; Maritan, A; Porporato, A; 10.1029/2010GL042495

2012-01-01

277

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

278

POTENTIAL FOR ADVERSE EFFECTS OF SOIL AS  

Science.gov (United States)

As is a natural constituent of soils and plants. The low soil As limit suggested by some (3.0 mg As/kg soil) is below natural background levels in US soils; thus validity of such limits is being questioned. Background As levels in US soils are 5-10 mg/kg, with range exceeding 20 mg/kg for acid sulfa...

279

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...

280

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

OpenAIRE

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 ...

Ahmed, Ashour; Leinweber, Peter; Ku?hn, Oliver

2013-01-01

281

Correlation between Soil Test Phosphorus of Kaolinitic and Smectitic Soils with Phosphorus Uptake of Lowland Rice  

OpenAIRE

Correlation between soil test phosphorus (P) and plant-available P parameters were affected by soil properties, such as soil pH, particle-size composition, and mineralogy. The objectives of this research were: (1) to determine P concentration extracted by several soil P test method in kaolinitic and smectitic soil, and (2) to determine correlation between soil P test and soil properties, P fractions, P sorption parameters, and P uptake of lowland rice. The soil P test in kaolinitic and smecti...

Mohammad Masjkur

2009-01-01

282

HUMUS SUBSTANCES AND SOIL FERTILITY  

OpenAIRE

The humus substances play an important role in obtaining high yields and stable over time. He is permanently double process: the humus improvement of organic material reaching the soil and the mineralization of components at different stages of humus improving, The results of this process is influenced by soil type, climate, irrigation, fertilization. The beneficial effect of humus substances on plant growth may be related to indirect effects (fertilization efficiency or reduce soil compacti...

Neagu, Cecilia Violeta; Oprea, Georgeta

2012-01-01

283

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

284

Stochastic Modeling of Soil Salinity  

OpenAIRE

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

2012-01-01

285

Soil classes and acceleration response  

International Nuclear Information System (INIS)

It could not enough for determination of only geotechnical properties (soil classification, soil type, bearing capacity etc.) in order to define assessment of areas being settle in terms of suitability of settlement or how settled area is affected from natural disaster and to get necessary precautions. Damages on the engineering structure in the region posses an earthquake hazard are affected one or more site condition from source point to soil of engineering structure

286

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

287

Effect of soil solarization on soil-borne pathogens  

International Nuclear Information System (INIS)

Author.Soil solarization was conducted at three locations on the Lebanese coast. Maximum soil temperatures recorded were 53 and 48 celsius degrees at Jiyeh, 48.9, 46 and 43 celsius degrees at Naameh and 48, 45 and 43.5 celsius degrees at Khaldeh at 5, 15 and 25cm soil depths respectively. Mean soil temperatures recorded at 3pm were at Jiyeh 51.6, 47 and 46 celsius degrees compared to Naameh 47, 45 and 41 celsius degrees and Khaldeh 44, 42 and 41 celsius degrees at 5, 15 and 25 cm respectively. The mean temperature in solarized soils were 7.3 to 15 celsius degrees higher than those of the nonsolarized soils indicating a sustained increase of soil temperature in the solarized soils. The effect of soil solarization on artificially introduced fungal pathogens in the soil at Khaldeh, resulted in complete destruction of sclerotia of Sclerotinia spp. at three depths studied. However, with respect to the two other pathogens tested, solarization resulted in reduction of the viability of microsclerotia of Verticillium spp. by 99-79% and of Fusarium oxysporum f. sp. melonis inoculum by 88-54% at 5 and 15 cm respectively, but only by 45% and 14% reduction at 25 cm. This level of control is significant when it is compared to the percentage of control where the level of reduction of inoculum viability did not exceed 10% at any soil depth. As there were contradicting reports in the literature on nematodes, two field trials in greenhouses were conducted to study the possibility of ine conducted to study the possibility of integrating 2 methods for management on nematodes. Soil solarization alone or in combination with biological control of nematodes using Arthrobotrys spp. and Dactyl ella brocophaga to control the root-knot nematodes on two crops, tomato at Naameh and cucumber at Jiyeh were compared to Methyl Bromide treatment. It was evident that, even on a very susceptible crop like cucumber, the integration of biological control and soil solarization gave a good level of control similar to methyl bromide. Neither root-knot indices nor yields were significantly different in both treatments. At present, fumigation with methyl bromide is the most common method adopted by Lebanese farmers to control soil-borne pathogens of high value crops in greenhouses. Since methyl bromide is extremely toxic and damage the ozone layer, and its use is banned in several countries and may be banned world wide in year 2001, these preliminary results prove that soil solarization may stand as a good alternative control measure

288

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

289

NASIS: National Soil Information System  

Science.gov (United States)

The National Soil Information System (NASIS) plays a role in the National Cooperative Soil Survey's goal of providing an active resource of soils information and "is designed to manage and maintain soil data from collection to dissemination." The website provides information and software downloads needed to access the NASIS system. Visitors can find helpful instructions on how to use the system as well as information on data problems. The website describes new works in progress and future plans. Users also have the opportunity to subscribe to NASISNEWS, the electronic mailing lists for NASIS users.

290

The importance of crop residue on soil aggregation and soil organic matter components  

Science.gov (United States)

Above- and below-ground plant residues are the soil’s main sources of organic materials that bind soil particles together into aggregates and increase soil carbon storage. Serving to stabilize soil particles, soil organic matter assists in supplying plant available nutrients, increases water holding...

291

Soil fauna community in the black soil of northeast China under different conservation tillage systems  

Science.gov (United States)

Soil fauna is an important component in soil ecosystem. Through the soil moisture changes, soil environment is changed under different tillage systems, and then the population of soil fauna also is changed. This study tested whether conservation tillage or conventional tillage (CT) of black soil fie...

292

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)

293

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

294

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)

295

Soil carbon sequestration estimated with the soil conditioning index  

Science.gov (United States)

Rapid and reliable assessments of the potential of different agricultural management systems to sequester soil organic carbon are needed to promote conservation and help mitigate greenhouse gas emissions. The soil conditioning index (SCI) is a relatively simple model to parameterize and is currentl...

296

From Soil Survey to Land Use Planning and National Soils Policies New Developments in Soil Science  

OpenAIRE

The emphasis of soil studies has shifted over the past decades from descriptive inventories towards a more specifie, pragmatic and problem solving approach related to land use and soil conservation. Under conditions of growing population density, land may become a source of conflict between various users : settled farmers, miners, stock breeders, foresters, urban planners, ecologists, ... In such cases, a national soils policy becomes imperative, as it provides a useful planning framework for...

Verheye, Wh

1997-01-01

297

Virtual Soils - Assessment of the Effects of Soil Structure on the Hydraulic Behavior of Cultivated Soils  

Science.gov (United States)

The hydraulic behavior of soil is determined by the spatial heterogeneity of its hydraulic properties. The interplay between parent material, pedogenesis and tillage leads to characteristic structures in cultivated soils: sealed or loosened soil surface, compacted plow pan and traffic lanes. These structures overlay with natural features such as biopores and boundaries between soil horizons. To assess the individual or combined impact of such structural components on soil hydrology, the heterogeneity of the soil must be known at a scale of several meters and at a resolution in the range of centimeters. This, however, cannot be achieved in experimental setups. An alternative solution is the generation of synthetic but realistic structures together with their hydraulic properties as a basis for modeling the hydraulic behavior in response to different boundary conditions. This approach is extendable to an arbitrary number of structural components. With such 'virtual soils' at hand, comparative studies are possible, that help quantifying the relation between soil architecture and soil function. Further, the existence of effective soil hydraulic properties, which are capable to predict the average water dynamics at the field scale, can be tested by inverse modeling. The evaluation of different "measured" data sets in terms of information content and usefulness for identifying suitable effective models and effective model parameters can be analyzed. We introduce a structure generator and present comparative simulations between soils with increasing complexity for a period of several weeks with precipitation and evaporation. The simulations demonstrate, that the structure and the hydraulic properties close to the soil surface clearly govern evaporation, while the impact of heterogeneity on groundwater recharge is more complex.

Vogel, H.; Schlüter, S.; Ippisch, O.; Roth, K.; Schelle, H.; Durner, W.; Kasteel, R.; Vanderborght, J.

2011-12-01

298

Soil organic matter studies  

International Nuclear Information System (INIS)

A total of 77 papers were presented and discussed during this symposium, 40 are included in Volume I. A number of papers deal with the behaviour and functions of organic matter and make a contribution to increasing agricultural production by proposing improved management practices. Other papers discuss turnover of plant residues, release of plant nutrients through biodegradation of organic compounds, and nitrogen economy and the dynamics of transformation of organic forms of nitrogen. Separate entries have been prepared for those 8 papers which discuss the use of tracer techniques in soil studies

299

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)

300

Relating soil biochemistry to sustainable crop production  

Science.gov (United States)

Amino acids, amino sugars, carbohydrates, phenols, and fatty acids together comprise appreciable proportions of soil organic matter (SOM). Their cycling contribute to soil processes, including nitrogen availability, carbon sequestration and aggregation. For example, soil accumulation of phenols has ...

301

Anthropogenic effects on soil micromycetes  

Directory of Open Access Journals (Sweden)

Full Text Available This paper is a synthesis of long-term investigations based on the effect of different authropogenic pollutants (mineral and organic fertilizers, heavy metals, contaminated irrigation water, nitrification inhibitor and detergents on the dynamics of soil fungi number. The investigations were performed at the Microbiology Department and trial fields of the Faculty of Agronomy in ?a?ak on smonitza and alluvium soils in field and under greenhouse conditions. Maize, wheat, barley and red clover were used as test plants in these studies. The quantitative composition of the fungi in the soils investigated was determined by the ?apek selective agar dilution method. The study results show that the number of soil fungi was dependent on the type and rate of agrochemicals used, on the growing season, and the soil zone the samples were taken from for the analysis. Lower nitrogen fertiliser rates (80 and 120 kg x ha-1 and organic fertilizers stimulated the development of soil fungi, unlike the rate of 150 kg x ha-1. Heavy metals, mercury and cadmium in particular, as well as high rates of the N-serve nitrification inhibitor, inhibited the development of this group of soil microorganisms. Generally, the adverse effect of contaminated irrigation water on the soil fungi was recorded in both soil types, and particularly in the smonitza under red clover. Low detergent (Meril concentrations did not have any significant effect on this group of microorganisms. In this respect, it can be concluded that the soil fungi number dynamics can be used in monitoring soils polluted by different toxinogenic substances.

?uki? Dragutin A.

2007-01-01

302

Soil washing of fluorine contaminated soil using various washing solutions.  

Science.gov (United States)

Bench-scale soil washing experiments were conducted to remove fluoride from contaminated soils. Five washing solutions including hydrochloric acid (HCl), nitric acid (HNO3), sodium hydroxide (NaOH), sulfuric acid (H2SO4) and tartaric acid (C4H6O6) were tested. The concentration of the washing solutions used ranged from 0.1 to 3 M with a liquid to solid ratio of 10. The soil washing results showed that the most effective washing solution for the removal of fluoride from contaminated soils was HCl. The highest fluoride removal results of approximately 97 % from the contaminated soil were obtained using 3 M HCl. The fluoride removal efficiency of the washing solution increases in the following order: C4H6O6 H2SO4 < HNO3 < HCl. PMID:25552323

Moon, Deok Hyun; Jo, Raehyun; Koutsospyros, Agamemnon; Cheong, Kyung Hoon; Park, Jeong-Hun

2015-03-01

303

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)

304

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

305

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

306

Soil classification and radionuclide migration in west Cumbrian soils  

International Nuclear Information System (INIS)

Radionuclide migration through soil is controlled by the degree of retardation due to sorption of the radionuclide onto the soil, which is dependant upon the soil type and nuclide involved. It is therefore important to assess the soil variability of the geographical area under study. Radionuclide attenuation is usually quantified by a distribution coefficient (Kd) or distribution ratio (Rd) obtained from batch experiments. As part of this research Rd values were compared with column retardation factors (Rf values) in order to assess how closely Rd values relate to radionuclide migration in an undisturbed soil. Results of this research have shown that the method and conditions used to conduct batch experiments can greatly affect the Kd and Rd values obtained. Rd values for a range of west Cumbrian soils were generally of the order 137Cs>60Co>125Sb>85Sr. The use of the national soil map of England and Wales (Jarvis et al., 1984) was not recommended for prediction of radionuclide migration in west Cumbrian soils. It was suggested that an Rd values for each major soil type (sand, clay, loam and peat) was sufficient for use in assessment studies. Modifications made to the batch method in this project did not appear to reduce the discrepancy which is often reported between batch and column retardation parameters. In general, the majority of the batch and column Rd values obtained in this research differed by one order of magnitudeesearch differed by one order of magnitude. There did not appear to be any trend, with regard to nuclide or soil type, in determining the magnitude by which the batch and column Rd values differed. Using the measured Rd values as input parameters in an advection-diffusion model produced mixed results, but the predicted activity-depth profiles generally underestimated the depths to which the radionuclides migrated down the column. (author)

307

Degradation kinetics of ptaquiloside in soil and soil solution.  

Science.gov (United States)

Ptaquiloside (PTA) is a carcinogenic norsesquiterpene glycoside produced in bracken (Pteridium aquilinum (L.) Kuhn), a widespread, aggressive weed. Transfer of PTA to soil and soil solution eventually may contaminate groundwater and surface water. Degradation rates of PTA were quantified in soil and soil solutions in sandy and clayey soils subjected to high natural PTA loads from bracken stands. Degradation kinetics in moist soil could be fitted with the sum of a fast and a slow first-order reaction; the fast reaction contributed 20 to 50% of the total degradation of PTA. The fast reaction was similar in all horizons, with the rate constant k(1F) ranging between 0.23 and 1.5/h. The slow degradation, with the rate constant k(1S) ranging between 0.00067 and 0.029/ h, was more than twice as fast in topsoils compared to subsoils, which is attributable to higher microbial activity in topsoils. Experiments with sterile controls confirmed that nonmicrobial degradation processes constituted more than 90% of the fast degradation and 50% of the slow degradation. The lower nonmicrobial degradation rate observed in the clayey compared with the sandy soil is attributed to a stabilizing effect of PTA by clay silicates. Ptaquiloside appeared to be stable in all soil solutions, in which no degradation was observed within a period of 28 d, in strong contrast to previous studies of hydrolysis rates in artificial aqueous electrolytes. The present study predicts that the risk of PTA leaching is controlled mainly by the residence time of pore water in soil, soil microbial activity, and content of organic matter and clay silicates. PMID:18348642

Ovesen, Rikke Gleerup; Rasmussen, Lars Holm; Hansen, Hans Christian Bruun

2008-02-01

308

Network models of soil porous structure  

OpenAIRE

Soils sustain life on Earth. In times of increasing anthropogenic demands on soils [1] there is growing need to seek for novel approaches to understand the relationships between the soil porous structure and speci?c soil functions. Recently [2-4], soil pore structure was described as a complex network of pores using spatially embedded varying ?tness network model [2] or heterogeneous preferential attachment scheme [3-4], both approaches revealing the apparent scale-free topology of soils....

Samec, M.; Santiago Andre?s, Antonio; Cardenas Villalobos, Juan Pablo; Benito Zafrilla, Rosa Maria; Tarquis Alfonso, Ana Maria; Mooney, S. J.; Koros?ak, D.

2012-01-01

309

Soil quality assessment using fuzzy modeling  

OpenAIRE

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 th...

Kurtener, D.; Krueger, E.; Torbert, H. A.

2008-01-01

310

Managing soils for long-term productivity  

OpenAIRE

Meeting the goal of long-term agricultural productivity requires that soil degradation be halted and reversed. Soil fertility decline is a key factor in soil degradation and is probably the major cause of declining crop yields. There is evidence that the contribution of declining soil fertility to soil degradation has been underestimated. Sensitivity to soil degradation is implicit in the assessment of the sustainability of land management practices, with wide recognition of the fact that soi...

Syers, J. K.

1997-01-01

311

Salt Affected Soils Their Identification and Reclamation  

OpenAIRE

Salt affected soils are found throughout the world especially in arid and semi arid regions. Soil salinization is mainly due to the use of saline water for irrigation, seepage from the canals, an arid climate evaporation of salty soil waters from the soil surface over shallow water tables and poor drainage. Salt effected soils are grouped into saline, alkali and saline-alkali soils. Three different ways viz. scrapping, surface flushing and leaching are normally used for reclamation of these s...

Siyal, A. A.; Siyal, A. G.; Abro, Z. A.

2002-01-01

312

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

313

Soil Radiological Characterisation Methodology  

International Nuclear Information System (INIS)

This report presents the general methodology and best practice approaches which combine proven existing techniques for sampling and characterisation to assess the contamination of soils prior to remediation. It is based on feedback of projects conducted by main French nuclear stakeholders involved in the field of remediation and dismantling (EDF, CEA, AREVA and IRSN). The application of this methodology will enable the project managers to obtain the elements necessary for the drawing up of files associated with remediation operations, as required by the regulatory authorities. It is applicable to each of the steps necessary for the piloting of remediation work-sites, depending on the objectives targeted (release into the public domain, re-use, etc.). The main part describes the applied statistical methodology with the exploratory analysis and variogram data, identification of singular points and their location. The results obtained permit assessment of a mapping to identify the contaminated surface and subsurface areas. It stakes the way for radiological site characterisation since the initial investigations from historical and functional analysis to check that the remediation objectives have been met. It follows an example application from the feedback of the remediation of a contaminated site on the Fontenay aux Roses facility. It is supplemented by a glossary of main terms used in the field from different publications or international standards. This technical report is a support of the ISO Standard ISO ISO/TC 85/SC 5 N 18557 'Sampling and characterisation principles for soils, buildings and infrastructures contaminated by radionuclides for remediation purposes'. (authors)

314

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.)

315

Brazilian Cerrado Soil Actinobacteria Ecology  

OpenAIRE

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 soils were characterised for chemical and microbiological analysis. The microbial analysis led to the identification of nine genera (Streptomyces, Arthrobacter, Rhodococcus, Amycolatopsis, Microbacterium, Frankia, Leifsonia, Nakamurella, and Kitasatospora) and 92 distinct species in both seasons studied (...

Monique Suela Silva; Alenir Naves Sales; Karina Teixeira Magalhães-Guedes; Disney Ribeiro Dias; Rosane Freitas Schwan

2013-01-01

316

Ants: the supreme soil manipulators  

Science.gov (United States)

This review focuses on the semiochemical interactions between ants and their soil environment. Ants occupy virtually every ecological niche and have evolved mechanisms to not just cope with, but also manipulate soil organisms. The metapleural gland, specific to ants was thought to be the major sourc...

317

Soil remediation process and system  

International Nuclear Information System (INIS)

This patent describes a process for remediation of soil containing up to about 30,000 ppm hydrocarbon contaminants. It comprises: providing hydrocarbon-contaminated soil in a divided condition of minus 1 1/2 double-prime to a first confined zone where it is exposed to an open flame; heating while agitating the contaminated soil in an oxidizing atmosphere in the first zone to a temperature below soil ignition within a range of from about 375 degrees F. to about 750 degrees F. for a time sufficient to drive off as vapors a substantial percentage of the hydrocarbon contaminates from the soil; passing hot gases containing the hydrocarbon contaminates from the soil; passing hot gases containing the hydrocarbon vapors from the first zone to a second zone; recovering heat from the hot gases in the second zone to condense a substantial percentage of the hydrocarbon vapors as liquid hydrocarbons; recovering the liquid hydrocarbons; and removing the soil from the first zone as remediated soil having below about 1000 ppm hydrocarbon contaminants

318

Degradation of monocrotophos in soils.  

Science.gov (United States)

The degradation of a widely used organophosphorus insecticide, monocrotophos (dimethyl (E)-1-methyl-2-methylcarbamoyl vinyl phosphate) in two Indian agricultural soils at two concentration levels, 10 and 100 microg g(-1) soil under aerobic conditions at 60% water-holding capacity at 28+/-4 degrees C was studied in a laboratory. The degradation of monocrotophos at both concentrations in black vertisol and red alfinsol soils was rapid accounting for 96-98% of the applied quantity and followed the first-order kinetics with rate constants (k) of 0.0753 and 0.0606 day(-1) and half-lives (t1/2) of 9.2 and 11.4 days, respectively. Degradation of monocrotophos in soils proceeded by hydrolysis with formation of N-methylacetoacetamide. Even three additions of monocrotophos at 10 microg g(-1) soil did not result in its enhanced degradation. However, there was cumulative accumulation of N-methylacetoacetamide in soils pretreated with monocrotophos to the tune of 7-15 microg g(-1) soil. Both biotic and abiotic factors were involved in degradation of monocrotophos in soils. PMID:15978655

Gundi, Vijay A K B; Reddy, B R

2006-01-01

319

Global Soil Moisture Data Bank  

Science.gov (United States)

This Data Bank is a collection of more than 400 observations of primarily Asian soil moisture. The data are freely available, and can be used for studying patterns of soil moisture variation, developing and testing land surface models, and ground truth for remote sensing.

Robock, Alan

320

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

321

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

322

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

323

Determination of chemical availability of cadmium and zinc in soils using inert soil moisture samplers.  

Science.gov (United States)

A rapid method for extracting soil solutions using porous plastic soil-moisture samplers was combined with a cation resin equilibration based speciation technique to look at the chemical availability of metals in soil. Industrially polluted, metal sulphate amended and sewage sludge treated soils were used in our study. Cadmium sulphate amended and industrially contaminated soils all had > 65% of the total soil solution Cd present as free Cd2+. However, increasing total soil Cd concentrations by adding CdSO4 resulted in smaller total soil solution Cd. Consequently, the free Cd2+ concentrations in soil solutions extracted from these soils were smaller than in the same soil contaminated by sewage sludge addition. Amendment with ZnSO4 gave much greater concentrations of free Zn2+ in soil solutions compared with the same soil after long-term Zn contamination via sewage sludge additions. Our results demonstrate the difficulty in comparing total soil solution and free metal ion concentrations for soils from different areas with different physiochemical properties and sources of contamination. However, when comparing the same Woburn soil, Cd was much less available as Cd2+ in soil solution from the CdSO4 amended soils compared with soil contaminated by about 36 years of sewage sludge additions. In contrast, much more Zn was available in soil solution as free Zn2+ in the ZnSO4 amended soils compared with the sewage sludge treated soils. PMID:15093293

Knight, B P; Chaudri, A M; McGrath, S P; Giller, K E

1998-01-01

324

Role of soil properties in water retention characteristics of main Hungarian soil types  

Directory of Open Access Journals (Sweden)

Full Text Available Relationship between easily available soil properties and soil water retention at given matric potentials were analysed on brown forest soils, chernozems and meadow soils of Hungarian Detailed Soil Hydrophysical Database (Hungarian acronym: MARTHA. We studied the influence of soil properties displayed on the 1:10000 scale Hungarian soil maps on soil water retention at -0.1, -33, -1500 and -150000 kPa. Continuous (particle size distribution, organic matter content, calcium carbonate content and pH and category type (ordinal: soil texture, ordinal type information on organic matter content, calcium carbonate content and pH; nominal: soil subtype classes variables were used in the analyses. The relationships was analysed with random forest method based on conditional inference trees (cforest. Water retention of different soil types was characterized. Importance of soil properties in the prediction of soil water content varies according to soil type and matric potentials.

Brigitta Toth

2014-06-01

325

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

326

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

327

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

328

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

329

Effects of soil tillage on the microwave emission of soils  

Science.gov (United States)

In order to understand the interactions of soil properties and microwave emission better, a series of field experiments were conducted in 1984. Small plots were measured with a truck-mounted passive microwave radiometer operating at 1.4 GHz. These data were collected concurrent with ground observations of soil moisture and bulk density. Treatment effects studied included different soil moisture contents and bulk densities. Evaluations of the data have shown that commonly used models of the dielectric properties of wet soils do not explain the observations obtained in these experiments. This conclusion was based on the fact that the roughness parameters determined through optimization were significantly larger than those observed in similar investigations. These discrepancies are most likely due to the soil structure. Commonly used models assume a homogeneous three phase mixture of soil solids, air and water. Under tilled conditions the soil is actually a two phase mixture of aggregates and voids. Appropriate dielectric models for this tilled condition were evaluated and found to explain the observations. These results indicate that previous conclusions concerning the effects of surface roughness in tilled fields may be incorrect, and they may explain some of the inconsistencies encountered in roughness modeling.

Jackson, T. J.; Koopman, G. J.; Oneill, P. E.; Wang, J. R.

1985-01-01

330

ESTIMATING SOIL PARTICLE-SIZE DISTRIBUTION FOR SICILIAN SOILS  

Directory of Open Access Journals (Sweden)

Full Text Available The soil particle-size distribution (PSD is commonly used for soil classification and for estimating soil behavior. An accurate mathematical representation of the PSD is required to estimate soil hydraulic properties and to compare texture measurements from different classification systems. The objective of this study was to evaluate the ability of the Haverkamp and Parlange (HP and Fredlund et al. (F PSD models to fit 243 measured PSDs from a wide range of 38 005_Bagarello(547_33 18-11-2009 11:55 Pagina 38 soil textures in Sicily and to test the effect of the number of measured particle diameters on the fitting of the theoretical PSD. For each soil textural class, the best fitting performance, established using three statistical indices (MXE, ME, RMSE, was obtained for the F model with three fitting parameters. In particular, this model performed better in the fine-textured soils than the coarse-textured ones but a good performance (i.e., RMSE < 0.03 was detected for the majority of the investigated soil textural classes, i.e. clay, silty-clay, silty-clay-loam, silt-loam, clay-loam, loamy-sand, and loam classes. Decreasing the number of measured data pairs from 14 to eight determined a worse fitting of the theoretical distribution to the measured one. It was concluded that the F model with three fitting parameters has a wide applicability for Sicilian soils and that the comparison of different PSD investigations can be affected by the number of measured data pairs.

Giuseppe Giordano

2009-09-01

331

Soil-structure interaction on inclined soil layers  

International Nuclear Information System (INIS)

The case history presented deals with a Category I building having two-thirds of its base founded on a wedge of hard material. This wedge is underlain by an inclined layer of softer material, which also directly supports the remaining one-third of the foundation. The inclined layer is underlain by a third material, possessing large stiffness and extending to great depth. This case is analyzed with the methodology described below: - Determination of the static soil compliances by discretizing the foundation area into a number of strips and taking the soil profile as horizontally layered under each strip. Lumped parameter soil compliances for the whole foundation are obtained by weighting the contributions to stiffness in proportion to the area of each strip. - Definition of the degree of coupling between modes. The soil compliances defined in the previous step include coupling between the vertical and rocking modes and the horizontal and torsional modes through the positioning of the corresponding soil springs. The degree of coupling is checked through a static finite element analysis. - Frequency correction of the static soil compliances taking into account the inhomogeneity of the foundation conditions. The correction is based on obtaining dynamic stiffness coefficients for extreme configurations of the soil profile. - Assessment of the sliding potential of the structure under earthquake loading, considering eccentricities of the dynamic forces and non-uniform fricti the dynamic forces and non-uniform friction resistance over the foundation area, accounting for the frictional capacity of the different bearing materials. It is concluded that the simplified technique can provide accurate soil compliances, coupling and frequency corrections for soil-structure interaction on sloping layers, and an appropriate assessment of the sliding potential. (orig./HP)

332

Evaluation of soil structure in the framework of an overall soil quality rating  

DEFF Research Database (Denmark)

Soil structure is an important aspect of agricultural soil quality, and its preservation and improvement are key to sustaining soil functions. Methods of overall soil quality assessment which include visual soil structure information can be useful tools for monitoring and managing the global soil resource. The aim of the paper is: (i) to demonstrate the role of visual quantification of soil structure within the procedure of the overall soil quality assessment by the Muencheberg Soil Quality Rating (M-SQR), (ii) to quantify the magnitude and variability of soil structure and overall M-SQR on a number of agricultural research sites and (iii) to analyse the correlations of soil quality rating results with crop yields. We analysed visual soil structure and overall soil quality on a range of 20 experimental sites in seven countries. To assess visual soil structure we utilised the Visual Soil Assessment (VSA) and Visual Evaluation of Soil Structure (VESS) methods. Results showed the feasibility and reliability of both VSA and VESS methods and the overall soil quality M-SQR rating approach to give scores and classes which characterised the soil potential for cropping. The structure status of soil can be reliably assessed by these procedures. In soils with clay contents > 30% unfavourable soil structure could not be reliably recognised by measurements of the dry bulk density, but significantly by evaluation of visual soil structure. Structure scores were clearly associated with the drainage status of soil. More than 70% of the variability of crop yields at a given intensity of input may be explained by the overall M-SQR-score which includes information on soil texture, relief and climate in addition to soil structure. We conclude that methods of visual soil assessment are useful diagnostic tools for monitoring and controlling agricultural soil quality over different scales, ranging from within-fields to global. Controlling the drainage status of land and action of machinery at appropriate drainage states are pre-conditions for preserving a suitable soil structure.

Mueller, L; Shepherd, T G

2013-01-01

333

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

OpenAIRE

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

Soil inoculation method determines the strength of plant-soil interactions  

OpenAIRE

There is increasing evidence that interactions between plants and biotic components of the soil influence plant productivity and plant community composition. Many plant–soil feedback experiments start from inoculating relatively small amounts of natural soil to sterilized bulk soil. These soil inocula may include a variety of size classes of soil biota, each having a different role in the observed soil feedback effects. In order to examine what may be the effect of various size classes of s...

Voorde, T. F. J.; Ruijten, M.; Putten, W. H.; Bezemer, T. M.

2012-01-01

335

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

336

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

337

A Review of Fishpond Soil Management Principles in Nigeria  

OpenAIRE

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

338

Rock and soil rheology  

International Nuclear Information System (INIS)

The aim of the Euromech Colloquium 196 devoted to Rock and Soil Rheology is to review some of the main results obtained in the last years in this field of research and also to formulate some of the major not yet solved problems which are now under consideration. Exchange of opinions and scientific discussions are quite helpful mainly in those areas where some approaches are controversial and the progress made is quite fast. That is especially true for the rheology of geomaterials, domain of great interest for mining and petroleum engineers, engineering geology, seismology, geophysics, civil engineering, nuclear and industrial waste storage, geothermal energy storage, caverns for sports, culture, telecommunications, storage of goods and foodstuffs (cold, hot and refrigerated storages), underground oil and natural gas reservoirs etc. Some of the last obtained results are mentioned in the present volume. (orig./HP)

339

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

340

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

341

Soil carbon dynamics inferred from carbon isotope compositions of soil organic matter and soil respiration  

International Nuclear Information System (INIS)

To better understand 14C cycling in terrestrial ecosystems, 14C abundances were evaluated for fractionated soil organic matter (SOM) and soil respiration in an urban forest. In 2001 soil profile, ? 14C values of litter and bulk SOM increased rapidly from litter surface (62.7 per mille) to uppermost mineral soil layer (244.9 per mille), and then decreased sharply to 6 cm depth of mineral soil (125.0 per mille). Carbon enriched in 14C by atmospheric nuclear weapons testing had penetrated to at least 16 cm depth of mineral soil. The average ? 14C in atmospheric CO2 was 58.8 per mille in August 2001, suggesting recent carbon input to the topmost litter layer. Although a similar depth distribution was observed for ? 14C values of residual SOM after acid hydrolysis, the ? 14C values were slightly lower than those in bulk SOM. This indicates input of 'bomb' C into this organic fraction and higher 14C abundance in acid-soluble SOM. The most of CO2 may be derived from the microbial decomposition of the acid-soluble, or labile, SOM. Therefore, the labile SOM may become most influential pool for soil carbon cycling. In contrast, carbon in base-insoluble SOM remained considerably low in 14C abundance at all depths, suggesting no or little incorporation of 'bomb' C to this fraction. Values of ? 14C in soil respiration ranged from 91.9 to 146.4 pepiration ranged from 91.9 to 146.4 per mille in August 2001, showing a significant contribution from decomposition of SOM fixed over past 2-40 years. These results indicate that the use of bulk SOM as a representative of soil carbon pool would lead to severe misunderstand of the soil C dynamics on decadal and shorter time scales. (author)

342

Anaerobic Soil Disinfestation (ASD) Combined with Soil Solarization as a Methyl Bromide Alternative: Vegetable Crop Performance and Soil Nutrient Dynamics  

Science.gov (United States)

Soil treatment by anaerobic soil disinfestation (ASD) combined with soil solarization can effectively control soilborne plant pathogens and plant-parasitic nematodes in specialty crop production systems. At the same time, research is limited on the impact of soil treatment by ASD + solarization on c...

343

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

344

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

345

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

346

Soil carbon determination by thermogravimetrics.  

Science.gov (United States)

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. PMID:23638398

Pallasser, Robert; Minasny, Budiman; McBratney, Alex B

2013-01-01

347

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

348

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

349

Methods of soil organic carbon determination in Brazilian savannah soils  

Scientific Electronic Library Online (English)

Full Text Available 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

Radionuclides distribution coefficient of soil to soil-solution  

International Nuclear Information System (INIS)

The present book addresses various issues related with the coefficient of radionuclides distribution between soil and soil solution. It consists of six sections and two appendices. The second section, following an introductory one, describes the definition of the coefficient and a procedures of its calculation. The third section deals with the application of the distribution coefficient to the prediction of movements of radionuclides through soil. Various methods for measuring the coefficient are described in the fourth section. The next section discusses a variety of factors (physical and chemical) that can affect the distribution coefficient. Measurements of the coefficient for different types of oils are listed in the sixth section. An appendix is attached to the book to show various models that can be helpful in applying the coefficient of distribution of radionuclides moving from soil into agricultural plants. (N.K.)

351

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

352

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

353

Soil temperature trends in Canada  

Science.gov (United States)

Global warming increasingly is becoming a concern for society. Most reported warming trends are based on measured increases in air temperatures. However, trends in soil temperatures, also an important indicator of climate change, are less often reported. Qian et al. analyzed soil temperature data from 30 climate stations across Canada covering the period from 1958 to 2008; the data cover soil temperatures at several depths up to 150 centimeters. They also analyzed air temperature, precipitation, and snow cover depth at the same locations. (Journal of Geophysical Research­Atmospheres, doi:10.1029/2010JD015012, 2011)

Tretkoff, Ernie

2011-04-01

354

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

355

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

356

Predicting hydrocarbon release from soil  

International Nuclear Information System (INIS)

'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 hydro 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)

357

Cesium-137 in Montana soils  

International Nuclear Information System (INIS)

Fallout 137Cs levels in soil were measured at 11 diverse sites throughout Montana. Concentrations in near-surface samples ranged from 20-200 mBq g-1 (0.51-5.41 pCi g-1). Most of the 137Cs was in the top 10 cm of soil. Deeper occurrences were attributed to disturbances by animals and to interstitial flow of small sediment particles within saturated soils. The areal concentrations ranged from 130-748 mBq cm-2 (3.6-20.2 pCi cm-2) and were highly correlated with annual precipitation

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

Soil biodiversity and soil community composition determine ecosystem multifunctionality  

OpenAIRE

Biological diversity is the foundation for the maintenance of ecosystems. Consequently it is thought that anthropogenic activities that reduce the diversity in ecosystems threaten ecosystem performance. A large proportion of the biodiversity within terrestrial ecosystems is hidden below ground in soils, and the impact of altering its diversity and composition on the performance of ecosystems is still poorly understood. Using a novel experimental system to alter levels of soil biodiversity and...

Wagg, Cameron; Bender, S. Franz; Widmer, Franco; Heijden, Marcel G. A.

2014-01-01

360

Numerical analysis of soil bearing capacity by changing soil characteristics  

Directory of Open Access Journals (Sweden)

Full Text Available In this research work by changing different parameters of soil foundation like density, cohesion and foundation depth and width of square foundation at angle of friction of 0° to 50° with increment of 5°, numerically safe bearing capacity of soil foundation is calculated and it is attempted to assess economical dimension of foundation as well as understanding variation range of bearing capacity at different degree. It could help of civil engineering in design of foundations at any situation.

Mehdi Khodashenas Pelko

2009-10-01

361

The use of some soil aggregate indices to assess potential soil loss in soils of south-eastern nigeria  

OpenAIRE

Six aggregate indices and some soil properties were evaluated to predict potential soil loss in soils of Southeastern Nigeria. Of the aggregate indices tested, dispersion ratio (DR), Wischmeier's erodibility index (K), clay dispersion index (CDI) and clay floccula-tion index (CFI) ranked higher than geometric mean diameter (GMD) and mean-weight diameter (MWD) in predicting potential soil loss. Some aggregate indices found to correlate well with soil loss are in order of decreasing predictabil...

Mbagwu, J. S. C.; Akamigbo, F. O. R.; Ca, Igwe

1995-01-01

362

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

OpenAIRE

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

Bio-energy and Soil Quality  

Science.gov (United States)

Soils are an important natural resource allowing the production of food, feed, fiber and fuel. The growing demand for these services or products requires that we protect the soil resource. Many characteristics of high quality soils can be related to the quantity and quality of soil organic matter (o...

364

SITE-SPECIFIC SOIL QUALITY MANAGEMENT  

Science.gov (United States)

Soil quality is a concept used to assess and monitor the ability of a soil to serve its various functions. This investigation covers four aspects of soil quality with a literature review, and provides complimentary research findings recently conducted on U.S. Midwest claypan soils. The four aspects ...

365

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

366

Elementary GLOBE Unit: The Scoop on Soils  

Science.gov (United States)

In this book and activities set, tThe GLOBE Kids are on the trail of Scoop, an eager dog who loves to dig holes in the soil. At each hole Scoop has dug, the kids make observations of the soil, learn about soil color, texture, structure, and about the “treasures” one can find in soil. *Activity 1: Getting to Know Soil* Students learn about soil profiles and the different properties of soil, including texture, color, and size. They will know that soil forms layers based on these properties. *Activity 2: Soil Treasure Hunt* Students learn about things found in soil, such as rocks, roots, critters, and organic material. They will understand that animals and microorganisms aid in the decomposition process that contributes organic materials to soil. *Activity 3: We All Need Soil!* Students will understand the importance of soil science and that soil is a limited resource on Earth. They will learn about soil’s function for plants and animals. The Elementary GLOBE unit was designed to introduce K-4 students to the study of Earth System Science. It includes five storybooks and 15 learning activities. The science content provided in the books serves as a springboard to GLOBE’s scientific protocols, and also provides student with an introduction to technology, a basic understanding of the methods of inquiry, and connections to math and literacy skills. Each book has associated hands-on learning activities to support learning exploration.

Becca Hatheway

2006-01-01

367

Fusarium Species Isolated from Forest Soil Samples  

OpenAIRE

A total of 46 isolates of Fusarium were isolated from six forest soil samples in Muka Head, Teluk Bahang, Pulau Pinang. Two Fusarium species were identified from the soil samples namely, F. solani (93.5%) and F. oxysporum (6.5%). The present study showed that the diversity and occurrences of Fusarium species in forest soil was low compared to cultivated soils.

Azaman, R. S.; Latiffah, Z.

2011-01-01

368

Soil Erosion. LC Science Tracer Bullet.  

Science.gov (United States)

Soil erosion is the detachment and movement of topsoil or soil material from the upper part of the soil profile. It may occur in the form of rill, gully, sheet, or wind erosion. Agents of erosion may be water, wind, glacial ice, agricultural implements, machinery, and animals. Soil conservation measures require a thorough understanding of the…

Buydos, John F., Comp.

369

Quantifying and modeling soil structure dynamics  

Science.gov (United States)

Characterization of soil structure has been a topic of scientific discussions ever since soil structure has been recognized as an important factor affecting soil physical, mechanical, chemical, and biological processes. Beyond semi-quantitative soil morphology classes, it is a challenge to describe ...

370

Relationships between soil erosion risk, soil use and soil properties in Mediterranean areas. A comparative study of three typical sceneries  

Science.gov (United States)

Generally, literature shows that the high variability of rainfall-induced soil erosion is related to climatic differences, relief, soil properties and land use. Very different runoff rates and soil loss values have been reported in Mediterranean cropped soils depending on soil management practices, but also in soils under natural vegetation types. OBJECTIVES The aim of this research is to study the relationships between soil erosion risk, soil use and soil properties in three typical Mediterranean areas from southern Spain: olive groves under conventional tillage, minimum tillage and no-till practices, and soils under natural vegetation. METHODS Rainfall simulation experiments have been carried out in order to assess the relationship between soil erosion risk, land use, soil management and soil properties in olive-cropped soils under different types of management and soils under natural vegetation type from Mediterranean areas in southern Spain RESULTS Results show that mean runoff rates decrease from 35% in olive grove soils under conventional tillage to 25% in olive (Olea europaea) grove soils with minimum tillage or no-till practices, and slightly over 22% in soils under natural vegetation. Moreover, considering the different vegetation types, runoff rates vary in a wide range, although runoff rates from soils under holm oak (Quercus rotundifolia), 25.70%, and marginal olive groves , 25.31%, are not significantly different. Results from soils under natural vegetation show that the properties and nature of the organic residues play a role in runoff characteristics, as runoff rates above 50% were observed in less than 10% of the rainfall simulations performed on soils with a organic layer. In contrast, more than half of runoff rates from bare soils reached or surpassed 50%. Quantitatively, average values for runoff water losses increase up to 2.5 times in unprotected soils. This is a key issue in the study area, where mean annual rainfall is above 600 mm. Regarding soil properties, the analysis shows that organic matter from soils under minimum tillage or no-till is strongly related with runoff, the amount of sediments in runoff and soil loss. In soils from olive groves, the amount of sediments in runoff was significantly related to soil pH. Moreover, for olive-cropped soils under conventional tillage, soil loss is strongly related with clayey texture, which is characteristic of these soils. Concerning this, the relationship between soil loss and coarse sand contents is highly significant, and shows that medium-sized soil particles are most prone to detachment and transport by runoff. Thus, the average content of these fractions in soils under conventional management is more than two times that from olive groves under minimal or no tillage, which are more coarsely textured. In fine-textured soils, hydraulic conductivity is reduced, thus increasing soil erosion risk. In addition, in sandy and silty soils with low clay content, infiltration rates are high even when soil sealing is observed. At the scale of this experiment, runoff generation and soil erosion risk decrease significantly in areas under natural vegetation, with lower clay contents

Gil, Juan; Priego-Navas, Mercedes; Zavala, Lorena M.; Jordán, Antonio

2013-04-01

371

TILL AND NO-TILL SOIL MANAGEMENT EFFECTS ON SOIL PHYSICAL PROPERTIES AND CORN YIELD  

Science.gov (United States)

Compacted soils generally have higher bulk density, increased mechanical impedance, and lower levels of water movement and oxygen than soils that are not compacted. Our objectives were to measure soil physical properties of soil under tilled and no-till soil management and to investigate the relati...

372

Scale Model of a Soil Aggregate and Associated Organisms: A Teaching Tool for Soil Ecology  

Science.gov (United States)

Soil is a complex habitat for diverse biota. A significant challenge in teaching soil ecology is our inability to observe organisms as they live and interact in the soil. The objective of this article is to describe an interactive class project to help students visualize the sizes of different groups of soil organisms and to relate these to soil

Bruns, Mary Ann; Byrne, Loren B.

2004-01-01

373

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

374

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 (pH, but showed no relationship with organic matter concentration, surface area, or imogolite and ferrihydrite concentrations. The reaction of iodide with the volcanic-ash soils is consistent with a rapid initial uptake by soil mineral surfaces, followed by a slower reaction of soil organic matter with oxidized forms of iodide. Under our experimental conditions, iodide is likely slowly oxidized by dissolved oxygen to molecular 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

375

Soil Organic Matter Quality From Soils Cropped by Traditional Peasants  

Directory of Open Access Journals (Sweden)

Full Text Available In this work we have analyzed soil samples from Oxisols collected from two traditional communities, one formed by Guarany Indians at South of Brazil and other by African descendants on North of Rio de Janeiro State, Brazil. The content and fractional composition of humus was investigated and the isolated humic acids (HAs were characterized by elemental composition, 13C solid-state nuclear magnetic resonance, and high-performance size exclusion chromatography. The bioactivity of HAs was evaluated considering the effects on root growth of maize seedlings. Chemical properties from adjacent soils under native forest were used as control samples. The local field sites matching the traditional cropping requirements, were characterized by higher soil chemical fertility and soil organic matter hydrophobicity, as compared to the land plots considered as inadequate by rural peasants. The HAs from cropped soils revealed significant differences in respect to content, hydrophobicity, biostimulation and molecular dimension. Although all humic extracts promoted, both, root growth and the stimulation of lateral root emergence over control, the HAs from preferential local sites, revealed a larger bioactivity response on root stimulation even at lower concentration. The assessment of soil quality issued by local farmers, showed a valuable fitting with bio-chemical fertility indicators and SOM hydrophobicity.

Luciano Pasqualoto Canellas

2014-08-01

376

Stocks of organic carbon in Estonian soils  

OpenAIRE

The soil organic carbon (SOC) stocks (Mg ha–1) ofautomorphic mineral (9 soil groups), hydromorphic mineral (7), and lowland organic soils (4) are given for the soil cover or solum layer as a whole and also for its epipedon (topsoil) layer. The SOC stocks for forest, arable lands, and grasslands and for the entire Estonian soil cover were calculated on the basis of the mean SOC stock and distribution area of the respective soil type. In the Estonian soil cover (42 400 km2), a total of 593.8 ...

Ko?lli, Raimo; Ellerma?e, Olav; Ko?ster, Tiia; Lemetti, Illar; Asi, Endla; Kauer, Karin

2009-01-01

377

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

378

Physical and Chemical Characteristics of Dokdo Soil  

OpenAIRE

To understand the properties of soil in Dokdo, we collected soil samples from 12 locations on Seodo and 23 locations on Dongdo, in Dokdo of Gyeongsangbuk-do Province in 2007-2008 and analyzed the soil’s physical and chemical characteristics. Sand comprises the largest component (49.37%) of Dokdo soil, followed by silt (40.70%) and clay (9.93%). The soil structure consists mostly of sand loam, followed by loam and silt loam. The pH level of soils from Dokdo varied dramatically among sampling...

Gil Seong Lee; Yeon Sik Choo

2009-01-01

379

Worldwide organic soil carbon and nitrogen data  

Energy Technology Data Exchange (ETDEWEB)

The objective of the research presented in this package was to identify data that could be used to estimate the size of the soil organic carbon pool under relatively undisturbed soil conditions. A subset of the data can be used to estimate amounts of soil carbon storage at equilibrium with natural soil-forming factors. The magnitude of soil properties so defined is a resulting nonequilibrium values for carbon storage. Variation in these values is due to differences in local and geographic soil-forming factors. Therefore, information is included on location, soil nitrogen content, climate, and vegetation along with carbon density and variation.

Zinke, P.J.; Stangenberger, A.G. [Univ. of California, Berkeley, CA (United States). Dept. of Forestry and Resource Management; Post, W.M.; Emanual, W.R.; Olson, J.S. [Oak Ridge National Lab., TN (United States)

1986-09-01

380

Microorganisms as Indicators of Soil Health  

DEFF Research Database (Denmark)

Microorganisms are an essential part of living soil and of outmost importance for soil health. As such they can be used as indicators of soil health. This report reviews the current and potential future use of microbial indicators of soil health and recommends specific microbial indicators for soil ecosystem parameters representing policy relevant end points. It is further recommended to identify a specific minimum data set for specific policy relevant end points, to carefully establish baseline values, to improve scientific knowledge on biodiversity and modelling of soil data, and to implement new indicators into soil monitoring programmes as they become applicable.

Nielsen, M. N.; Winding, A.

2002-01-01

381

Soil Sampling Techniques and Data Sheet  

Science.gov (United States)

In this activity students collect a representative soil sample from a piece of land as an introduction to soil testing and other soil activities. Using the sampling patterns and techniques discussed in class, they will collect and label a sample of soil from their garden, lawn, or fields. Using the provided Soil Data Sheet, students will record information about their soil as they develop it. A soil data sheet consists of the results of a series of tests and other significant information that one obtains about a specific soil sample from a known location. The types of information include: specific soil name, texture, slope of soil, colorations of the subsoil horizons, organic matter content (OM), percolation rate, results of macronutrient tests for nitrogen, potassium, and phosphorus, and the results of a pH test. Other information can be added as needed or desired.

382

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

383

Phytoremediation of Soil Trace Elements  

Science.gov (United States)

Phytoremediation includes several distinct approaches to using plants to achieve soil remediation goals. Phytoextraction uses rare hyperaccumulator plants to accumulate in their shoots enough metals per year to achieve decontamination goals. Phytomining uses hyperaccumulators and biomass burn to pro...

384

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%

385

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

386

Proceedings of hydrocarbon contaminated soils  

International Nuclear Information System (INIS)

While the 1980s witnessed a concentrated effort toward identifying the scientific concerns associated with hydrocarbon contaminated soils, the 1990s offer the hope that even more reliable solutions, both scientific and regulatory, will emerge. The hope for this transition from problem identification to problems solution is evident in these papers from the 5th Annual Conference on Hydrocarbon Contaminated Soils (formerly called Petroleum Contaminated Soils), as the presentations more clearly reflect the maturation of a rapidly evolving field in the areas of chemical analysis, fate, remediation, public health, and regulatory evaluation. This book attempts to address the multidimensional facets of soil contamination by providing various current general perspectives as well as those from the regulatory and the international communities. Technical information is also provided in specific contamination areas such as diesel fuel, as well as analysis and site assessment, remediation, risk assessment, and management

387

Daily estimates of soil ingestion in children.  

OpenAIRE

Soil ingestion estimates play an important role in risk assessment of contaminated sites, and estimates of soil ingestion in children are of special interest. Current estimates of soil ingestion are trace-element specific and vary widely among elements. Although expressed as daily estimates, the actual estimates have been constructed by averaging soil ingestion over a study period of several days. The wide variability has resulted in uncertainty as to which method of estimation of soil ingest...

Stanek, E. J.; Calabrese, E. J.

1995-01-01

388

Tropical Volcanic Soils From Flores Island, Indonesia  

OpenAIRE

Soils that are developed intropical region with volcanic parent materials have many unique properties, and high potential for agricultural use.The purpose of this study is to characterize the soils developed on volcanic materials from Flores Island, Indonesia,and to examine if the soils meet the requirements for andic soil properties. Selected five soils profiles developed fromandesitic volcanic materials from Flores Island were studied to determine their properties. They were compared inthei...

Hikmatullah; Kesumo Nugroho

2010-01-01

389

Soil as a filter for groundwater quality  

OpenAIRE

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

390

Agriculture Canada Central Saskatchewan Vector Soils Data  

Science.gov (United States)

This data set consists of GIS layers that describe the soils of the BOREAS SSA. These original data layers were submitted as vector data in ARC/INFO EXPORT format. These data also include the soil name and soil layer files, which provide additional information about the soils. There are three sets of attributes that include information on the primary, secondary, and tertiary soil type within each polygon. Thus, there is a total of nine main attributes in this data set.

Knapp, David; Hall, Forrest G. (Editor); Rostad, Harold

2000-01-01

391

Soil quality and methods for its assessment  

OpenAIRE

Environmental sustainability will only be achieved by maintenance and improvement of soil quality. Soil quality is considered as the capacity of a soil to function. Its assessment focuses on dynamic aspects to evaluate the sustainability of soil management practices. In this chapter, a wide perspective of soil quality and the complex task of its assessment, considering the inherent and dynamic factors, are introduced. It focuses on the possibilities of applying and integrating the accumulated...

La Rosa, Diego; Sobral, Ramo?n

2008-01-01

392

Anthropogenic effects on soil micromycetes  

OpenAIRE

This paper is a synthesis of long-term investigations based on the effect of different authropogenic pollutants (mineral and organic fertilizers, heavy metals, contaminated irrigation water, nitrification inhibitor and detergents) on the dynamics of soil fungi number. The investigations were performed at the Microbiology Department and trial fields of the Faculty of Agronomy in ?a?ak on smonitza and alluvium soils in field and under greenhouse conditions. Maize, wheat, barley and red clover...

?uki? Dragutin A.; Mandi? Leka G.; Šumanov Vesna; Raketi? Svetlana

2007-01-01

393

Closeup View of Compacted Soil  

Science.gov (United States)

Soil on Mars can be a bit clumpy, as shown in this image of soil after it was compacted by one of the wheels of NASA's Mars Exploration Rover Spirit. Scientists think the light-colored material may be a global layer of airfall dust. Spirit's microscopic imager took this picture, showing an area approximately 3 centimeters (1.2 inches) square, during the rover's 314th martian day, or sol (Nov. 19, 2004).

2004-01-01

394

Soil erosion and agricultural sustainability  

OpenAIRE

Data drawn from a global compilation of studies quantitatively confirm the long-articulated contention that erosion rates from conventionally plowed agricultural fields average 1–2 orders of magnitude greater than rates of soil production, erosion under native vegetation, and long-term geological erosion. The general equivalence of the latter indicates that, considered globally, hillslope soil production and erosion evolve to balance geologic and climate forcing, whereas conventional plow-b...

Montgomery, David R.

2007-01-01

395

Soil analysis. Modern instrumental technique  

International Nuclear Information System (INIS)

This book covers traditional methods of analysis and specialist monographs on individual instrumental techniques, which are usually not written with soil or plant analysis specifically in mind. The principles of the techniques are combined with discussions of sample preparation and matrix problems, and critical reviews of applications in soil science and related disciplines. Individual chapters are processed separately for inclusion in the appropriate data bases

396

Soil remediation: a systems approach.  

OpenAIRE

Soil remediation has only a short history, but the problem addressed is a significant one. When solving soil remediation problems we have to deal with a large number of scientific disciplines, however solutions are often presented from the viewpoint of just one discipline. In order to benefit from the combined disciplinary knowledge and experience it is necessary to describe the interrelations between these disciplines. This has been realised by developing an adequate model of the desired pro...

Okx, J. P.

1998-01-01

397

Soil biodiversity for agricultural sustainability  

OpenAIRE

We critically highlight some evidence for the importance of soil biodiversity to sustaining (agro-)ecosystem functioning and explore directions for future research. We first deal with resistance and resilience against abiotic disturbance and stress. There is evidence that soil biodiversity does confer stability to stress and disturbance, but the mechanism is not yet fully understood. It appears to depend on the kind of stress and disturbance and on the combination of stress and disturbance ef...

Brussaard, L.; Ruiter, P. C.; Brown, G. G.

2007-01-01

398

Lunar soils grain size catalog  

Science.gov (United States)

This catalog compiles every available grain size distribution for Apollo surface soils, trench samples, cores, and Luna 24 soils. Original laboratory data are tabled, and cumulative weight distribution curves and histograms are plotted. Standard statistical parameters are calculated using the method of moments. Photos and location comments describe the sample environment and geological setting. This catalog can help researchers describe the geotechnical conditions and site variability of the lunar surface essential to the design of a lunar base.

Graf, John C.

1993-01-01

399

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

400

Review of soil contamination guidance  

International Nuclear Information System (INIS)

A review of existing and proposed radioactive soil contamination standards and guidance was conducted for United Nuclear Corporation (UNC), Office of Surplus Facilities Management. The more applicable standards were reviewed, evaluated and summarized. Information pertaining to soil contamination for both facility operation and facility decommissioning was obtained from a variety of sources. Most of the information reviewed was consistent with the philosophy of maintaining exposures at levels as low as reasonably achievable

401

Martian gas, soil sampler tested.  

Science.gov (United States)

A gas chromatograph mass spectrometer (GCMS) is scheduled to be carried aboard the Mars Viking lander, which is to make a soft landing on the Martian surface. The GCMS has two distinct tasks including a sampling of the Martian atmosphere and an analysis of Martian soil. The instrument is designed to be highly sensitive. It can detect 0.1 part per million of organic compounds in the soil and from 10 to 100 parts per million of atmospheric constituents.

Miller, B.

1972-01-01

402

Bioremediating herbicide-contaminated soils.  

Science.gov (United States)

Combinations of landfarming and biostimulation were evaluated for remediating pesticide wastes. Various amounts of soil contaminated with alachlor and trifluralin (> or = 100 mg/kg each) and metolachlor and atrazine (> or = 20 mg/kg each) were applied to field plots, and sewage sludge or corn meal was incorporated into designated plots. Plots were also treated with fresh spray mixtures in amounts similar to those applied as contaminated soil. Soil bioactivity and dissipation of parent herbicides were monitored after the treatments. During 100 d, soil dehydrogenase activities were highest in organic-material-amended plots. During the same period, the levels of alachlor had declined by 85-95% in amended, contaminated soil-treated plots and by 75-85% in corresponding unamended plots. In freshly sprayed plots, 95-100% of the initial doses of alachlor had dissipated in amended plots, and 85-95% was lost in corresponding unamended plots. The levels of trifluralin had declined by 70-80% in corn-meal-amended plots and by 60-75% in unamended plots. There were no significant differences between dissipation of trifluralin applied as contaminated soil or fresh sprays. PMID:8323266

Dzantor, E K; Felsot, A S; Beck, M J

1993-01-01

403

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 soils were characterised for chemical and microbiological analysis. The microbial analysis led to the identification of nine genera (Streptomyces, Arthrobacter, Rhodococcus, Amycolatopsis, Microbacterium, Frankia, Leifsonia, Nakamurella, and Kitasatospora) and 92 distinct species in both seasons studied (rainy and dry). The rainy season produced a high microbial population of all the aforementioned genera. The pH values of the soil samples from the Passos, Luminárias, and Arcos regions varied from 4.1 to 5.5. There were no significant differences in the concentrations of phosphorus, magnesium, and organic matter in the soils among the studied areas. Samples from the Arcos area contained large amounts of aluminium in the rainy season and both hydrogen and aluminium in the rainy and dry seasons. The Actinobacteria population seemed to be unaffected by the high levels of aluminium in the soil. Studies are being conducted to produce bioactive compounds from Actinobacteria fermentations on different substrates. The present data suggest that the number and diversity of Actinobacteria spp. in tropical soils represent a vast unexplored resource for the biotechnology of bioactives production. PMID:23555089

Suela Silva, Monique; Naves Sales, Alenir; Teixeira Magalhães-Guedes, Karina; Ribeiro Dias, Disney; Schwan, Rosane Freitas

2013-01-01

404

The nature of lunar soil  

Science.gov (United States)

Characteristics of lunar soil are examined. The paper includes topics such as lunar soil genesis, particle types, grain size distribution, grain shape distribution, specific gravity, minimum and maximum density, and relative density. Lunar soil, consisting of complex mixtures of mineral fragments, miscellaneous glasses, agglutinates, and lithic fragments, is produced primarily by meteorite impacts. The grain size distributions for soils exposed to meteorite reworking for 100 million yr or more are classified as well-graded silty sands and sandy silts. The specific gravity of submillimeter lunar soil samples varies from 2.9 to 3.24 and individual particles range from 1.0 to greater than 3.32. Differences in specific gravity, intragranular porosity, particle shape, surface texture, and grain arrangements result in wide ranges in minimum and maximum densities. Meteorite impacts cause in situ lunar soil to have a low relative density at the surface which increases rapidly to a very high relative density at depths greater than 10 cm to 20 cm.

Carrier, W., III; Mitchell, J. K.; Mahmood, A.

1973-01-01

405

Electrokinetic remediation of contaminated soils  

International Nuclear Information System (INIS)

Electrokinetic remediation of contaminated soil has been demonstrated for saturated and unsaturated sand in preliminary experiments using a novel transport visualization technique. Large anionic organic dyes were mixed with a portion of soil and the rate of electromigration of the dye in an imposed electric field was monitored photographically. One of the fastest current-normalized electromigration rates was measured in the driest sand, which contained 7% water by-weight. This moisture content is typical of the moisture content in the unsaturated zone of subsurface native soils found in New Mexico. The characteristics of the electromigration were similar in both the saturated and unsaturated sand. The leading edge of the dye migration front was diffuse while the trailing edge was sharp and concentrated. This and other observed behavior may indicate a concentration effect, where the electromigration rate of dilute dye is greater than that of concentrated dye. The soil left after the trailing edge passed seemed to contain no residual dye in both the saturated and unsaturated cases. The success of demonstrating electromigration of large molecules in unsaturated soil is encouraging and indicates that it may be feasible to remediate in situ anionic heavy metals such as chromate from unsaturated soil with electrokinetic techniques

406

Soil contamination; 1 : 500 000  

International Nuclear Information System (INIS)

Inorganic soil contamination is expressed by the intersection of the sets of contents of risk elements exceeding the threshold values. It was compiled from the mono-element geochemical maps made by application of geostatistical methods based on the results of 5,189 chemical analyses of forest and agricultural soils. The density of soil sampling was 1 sample per 10 square kilometres in average. Point and diffuse soil contamination according to the limits in force (Decision of the Ministry of Agriculture of the Slovak Republic No. 531/1994-540) is represented on the map. The extent of the areas with relatively clean soils and the areas with higher background concentration of elements in soil is obvious. The spreading of the limit exceeding contents of risk elements is related to the geochemical, but above all anthropogenically produced, contamination sources in the areas of old mining, processing and metallurgical factories (Central Slovakia and the Spis-Gemer area). It also indicates the transfer of contaminants into the alluvial zones of rivers and brooks. (authors)

407

Bioremediation of petroleum contaminated soil  

International Nuclear Information System (INIS)

This paper reports on bioremediation, which offers a cost-competitive, effective remediation alternative for soil contaminated with petroleum products. These technologies involve using microorganisms to biologically degrade organic constituents in contaminated soil. All bioremediation applications must mitigate various environmental rate limiting factors so that the biodegradation rates for petroleum hydrocarbons are optimized in field-relevant situations. Traditional bioremediation applications include landfarming, bioreactors, and composting. A more recent bioremediation application that has proven successful involves excavation of contaminated soil. The process involves the placement of the soils into a powerscreen, where it is screened to remove rocks and larger debris. The screened soil is then conveyed to a ribbon blender, where it is mixed in batch with nutrient solution containing nitrogen, phosphorus, water, and surfactants. Each mixed soil batch is then placed in a curing pile, where it remains undisturbed for the remainder of the treatment process, during which time biodegradation by naturally occurring microorganisms, utilizing biochemical pathways mediated by enzymes, will occur

408

Electrokinetic remediation of contaminated soils  

International Nuclear Information System (INIS)

Electrokinetic remediation of contaminated soil has been demonstrated for saturated and unsaturated sand in preliminary experiments using a novel transport visualization technique. Large anionic organic dyes were mixed with a portion of soil and the rate of electromigration of the dye in an imposed electric field was monitored photographically. One of the fastest current-normalized electromigration rates was measured in the driest sand, which contained 7% water by weight. This moisture content is typical of the moisture content in the unsaturated zone of subsurface native soils found in New Mexico. The characteristics of the electromigration were similar in both the saturated and unsaturated sand. The leading edge of the dye migration front was diffuse while the trailing edge was sharp and concentrated. This and other observed behavior may indicate a concentration effect, where the electromigration rate of dilute dye is greater than that of concentrated dye. The soil left after the trailing edge passed seemed to contain no residual dye in both the saturated and unsaturated cases. The success of demonstrating electromigration of large molecules in unsaturated soil is encouraging and indicates that it may be feasible to remediate in situ anionic heavy metals such as chromate from unsaturated soil with electrokinetic techniques. 23 refs., 7 figs

409

Denitrification in suburban lawn soils.  

Science.gov (United States)

There is great uncertainty about the fate of nitrogen (N) added to urban and suburban lawns. We used direct flux and in situ chamber methods to measure N and NO fluxes from lawns instrumented with soil O sensors. We hypothesized that soil O, moisture, and available NO were the most important controls on denitrification and that N and NO fluxes would be high following fertilizer addition and precipitation events. While our results support these hypotheses, the thresholds of soil O, moisture, and NO availability required to see significant N fluxes were greater than expected. Denitrification rates were high in saturated, fertilized soils, but low under all other conditions. Annual denitrification was calculated to be 14.0 ± 3.6 kg N ha yr, with 5% of the growing season accounting for >80% of the annual activity. Denitrification is thus an important means of removing reactive N in residential landscapes, but varies markedly in space, time, and with factors that affect soil saturation (texture, structure, compaction) and NO availability (fertilization). Rates of in situ NO flux were low; however, when recently fertilized soils saturated with water were incubated in the laboratory, we saw extraordinarily high rates of NO production for the first few hours of incubation, followed by rapid NO consumption later in the experiment. These findings indicate a lag time between accelerated NO production and counterbalancing increases in NO consumption; thus, we cannot yet conclude that lawns are an insignificant source of NO in our study area. PMID:22031577

Raciti, Steve M; Burgin, Amy J; Groffman, Peter M; Lewis, David N; Fahey, Timothy J

2011-01-01

410

Soil Degradation and Soil Quality in Western Europe: Current Situation and Future Perspectives  

Directory of Open Access Journals (Sweden)

Full Text Available The extent and causes of chemical, physical and biological degradation of soil, and of soil loss, vary greatly in different countries in Western Europe. The objective of this review paper is to examine these issues and also strategies for soil protection and future perspectives for soil quality evaluation, in light of present legislation aimed at soil protection. Agriculture and forestry are the main causes of many of the above problems, especially physical degradation, erosion and organic matter loss. Land take and soil sealing have increased in recent decades, further enhancing the problems. In agricultural land, conservation farming, organic farming and other soil-friendly practices have been seen to have site-specific effects, depending on the soil characteristics and the particular types of land use and land users. No single soil management strategy is suitable for all regions, soil types and soil uses. Except for soil contamination, specific legislation for soil protection is lacking in Western Europe. The Thematic Strategy for Soil Protection in the European Union has produced valuable information and has encouraged the development of networks and databases. However, soil degradation is addressed only indirectly in environmental policies and through the Common Agricultural Policy of the European Union, which promotes farming practices that support soil conservation. Despite these efforts, there remains a need for soil monitoring networks and decision-support systems aimed at optimization of soil quality in the region. The pressure on European soils will continue in the future, and a clearly defined regulatory framework is needed.

Iñigo Virto

2014-12-01

411

Soil hydrologic characterization for modeling large scale soil remediation protocols  

Science.gov (United States)

In Campania Region (Italy), the Ministry of Environment identified a National Interest Priority Sites (NIPS) with a surface of about 200,000 ha, characterized by different levels and sources of pollution. This area, called Litorale Domitio-Agro Aversano includes some polluted agricultural land, belonging to more than 61 municipalities in the Naples and Caserta provinces. In this area, a high level spotted soil contamination is moreover due to the legal and outlaw industrial and municipal wastes dumping, with hazardous consequences also on the quality of the water table. The EU-Life+ project ECOREMED (Implementation of eco-compatible protocols for agricultural soil remediation in Litorale Domizio-Agro Aversano NIPS) has the major aim of defining an operating protocol for agriculture-based bioremediation of contaminated agricultural soils, also including the use of crops extracting pollutants to be used as biomasses for renewable energy production. In the framework of this project, soil hydrologic characterization plays a key role and modeling water flow and solute transport has two main challenging points on which we focus on. A first question is related to the fate of contaminants infiltrated from stormwater runoff and the potential for groundwater contamination. Another question is the quantification of fluxes and spatial extent of root water uptake by the plant species employed to extract pollutants in the uppermost soil horizons. Given the high variability of spatial distribution of pollutants, we use soil characterization at different scales, from field scale when facing root water uptake process, to regional scale when simulating interaction between soil hydrology and groundwater fluxes.

Romano, Nunzio; Palladino, Mario; Di Fiore, Paola; Sica, Benedetto; Speranza, Giuseppe

2014-05-01

412

REDUCING CHILDREN'S RISK TO SOIL LEAD: SUMMARY OF A FIELD EXPERIMENT TO REDUCE SOIL LEAD BIOAVAILABILITY  

Science.gov (United States)

Reducing risks associated with Pb in soil has typically been accomplished by soil removal, covering, or dilution by mixing with uncontaminated soil. EPA's National Risk Management Research Laboratory (NRMRL) and DuPont Corporation established a collaborative effort to evaluation...

413

The role of soil macrofauna in soil formation and carbon storage in post-mining sites.  

Czech Academy of Sciences Publication Activity Database

Boca Raton : Taylor & Francis CRC Press, 2013, s. 236-249. ISBN 978-1-4665-9931-4 Institutional support: RVO:60077344 Keywords : post-mining sites * soil macrofauna * soil formation * carbon storage Subject RIV: DF - Soil Science