This paper explores the potential to improve the impervious surface estimation accuracy using a multi-stage approach on the basis of vegetation-impervious surface-soil (V-I-S) model. In the first stage of Spectral Mixture Analysis (SMA) process, pixel purity index, a quantitative index for defining endmember quality, and a 3-dimensional endmember selection method were applied to refining endmembers. In the second stage, instead of obtaining impervious surface fraction by adding high and low albedo fractions directly, a linear regression model was built between impervious surface and high/low albedo using a random sampling method. The urban impervious surface distribution in the urban central area of Shanghai was predicted by the linear regression model. Estimation accuracy of spectral mixt...

As development progresses in a urban environment, the impervious areas that rapidly contribute runoff to the receiving water bodies increase while the pervious areas that store and deliver subsurface flow over periods of hours, days or weeks diminish, with the direct consequence of higher runoff rates and volumes and shorter times of concentration. The construction of impervious surfaces modifies the surrounding soils through engineered compaction and eliminates superficial soil and its role as a significant pervious storage interface between the subsurface and the atmosphere. There are documented case studies that conclusively link urbanization and increased watershed imperviousness to hydrologic impacts on streams. The Effective Impervious Area (EIA) in a watershed is the impervious area directly connected to the storm drainage system that contributes to increased storm water volumes and runoff rates. It is shown in the literature that a reduction of EIA could compensate the adverse impact of possible global warming scenarios on urban hydrology and in particular on the efficiency of a combined sewer system. In this paper, the implementation of green roofs is analyzed as a technique able to reduce the amount of EIA in order to mitigate the impact of urbanization on the hydrologic response of the urban catchment of Colle Ometti in the town of Genoa (Italy). Although no green roof installations are now present in the area, this study modelled - using extensive green roof details - the hydrologic effects of hypothetical roof greening scenarios. The modelling of green roof systems was undertaken using the EPA SWMM and was calibrated and validated on a small size green roof test bed completed in September 2007 in the laboratory of the Department of Civil, Environmental and Architectural Engineering (DICAT - University of Genova).

Urban systems are characterized by wide temporal fluctuations in environmental conditions that are superimposed on a highly disturbed ecosystem. A simple, multi-media model is developed to begin to understand the fate of organic contaminants in the urban environment. Based on an equilibrium fugacity model, the model incorporates impervious surfaces that comprise a large percentage of surface area in urbanized watersheds, in addition to other media considered, e.g., soil, air, surface water, sediment and vegetation. It is hypothesized that an organic film coats impervious surfaces and provides an active layer into which organic chemicals partition. The layer originates from (a) condensation of secondary organic compounds formed in atmospheric reactions, and (b) deposition of uncombusted and partially combusted hydrocarbons from vehicles. The model was applied to the Don River watershed, located in central Toronto. Model results indicate that elevated concentrations of high K{sub ow} chemicals considered, namely y-HCH, PCBs and B(a)P, occur in the organic film. The more volatile chemicals modeled, chloroform and naphthalene, remain in the air phase, as expected given their physical chemical properties. Urban soils and vegetation are significant reservoirs of chemical in the watershed. Overall, the results suggest that an organic film on impervious surfaces may act as a temporary sink for persistent organic compounds and affect their multi-media distribution.

Remote sensing estimation of impervious surfaces is significant in monitoring urban development and determining the overall environmental health of a watershed, and has therefore recently attracted increasing interest. The main objective of this study was to develop a general approach to estimating and mapping impervious surfaces by using medium spatial resolution satellite imagery. We have applied spectral mixture analysis (SMA) to Earth Observing 1 (EO-1) Advanced Land Imager (ALI) (multispectral) and Hyperion (hyperspectral) imagery in Marion County, Indiana, USA, to calculate the fraction images of vegetation, soil, high albedo and low albedo. The effectiveness of the two images was compared according to three criteria: (1) high-quality fraction images for the urban landscape, (2) rela...

The knowledge of impervious surfaces, especially the magnitude, location, geometry, spatial pattern of impervious surfaces and the perviousness-imperviousness ratio, is significant to a range of issues and themes in environmental science central to global environmental change and human-environment interactions. Impervious surface data is important for urban planning and environmental and resources management. Therefore, remote sensing of impervious surfaces in the urban areas has recently attracted unprecedented attention. In this paper, various digital remote sensing approaches to extract and estimate impervious surfaces will be examined. Discussions will focus on the mapping requirements of urban impervious surfaces. In particular, the impacts of spatial, geometric, spectral, and tempora...

Observations of increasingly impervious areas resulting from urbanization and redevelopment and observed increases in rainfall, combined with long-term climate change scenarios suggest storm water management source control as the most appropriate potential application for green roofs. This conclusion was reached after intensive investigation of the hydrologic performance of green roofs for a variety of soil types, percentages of green roof area and precipitation scenarios, through continuous simulation modeling at both site and watershed scales. Results of this investigation are discussed in this paper. 29 figs.

Ten multipurpose tree species, Terminalia arjuna, Azadirechta indica, Prosopis juliflora, Pongamia pinnata, Casuarina equisetifolia, Prosopis alba, Acacia nilotica, Eucalyptus tereticornis, Pithecellobium dulce and Cassia siamea, were raised in a monoculture tree cropping system on the sodic soil of Gangetic alluvium in north India (26? 47? N: 80?46? E) for 10 years to evaluate the biomass and bio-energy production. The soil was compact, sodic and impervious to water associated with nutrient deficiency or toxicity. Maximum plant height was recorded with E. tereticornis followed by C.equisetifolia and P. juliflora. A. nilotica performed better than the other species in terms of diameter at breast height (DBH) with a basal area of 13.04 m2?ha?1, followed by P. juliflora and C. equisetifolia....

More than half of humanity lives in urban areas, projected to exceed 80% by 2015. Urban areas are major sources of environmental contaminants and sinks of energy and materials. Globally, remote sensing contributes to improved understanding of urban impacts through mapping urban extent, vegetation and impervious cover fractions and urban energy balance including albedo, emissivity and land surface temperature (LST). HyspIRI is a NRC "Decadal Survey" mission combining a visible, near-infrared and shortwave infrared (VSWIR) imaging spectrometer with a multispectral thermal infrared (TIR) instrument . Potential synergies between VSWIR and TIR data were explored using analogous airborne data acquired over Santa Barbara in June, 2008. These data were analyzed at their native spatial resolutions (7.5m VSWIR and 15m TIR), and aggregated 60 m spatial resolution similar to HyspIRI. A spectral library of common urban materials (e.g., grass, trees, soil, roofs, roads) was built from field and airborne-measured spectra . LST and emissivity were also retrieved from the airborne data. Co-located pixels from airborne data were used to generate reflectance/emissivity spectra for a subset of urban materials. Multiple Endmember Spectral Mixture Analysis (MESMA) was used to map fractions of impervious, soil, green vegetation (GV) and non-photosynthetic vegetation (NPV) at the different spatial resolutions and to compare the fractional estimates across spatial scales. Surface energy parameters, including albedo, vegetation cover fraction, broadband emissivity and LST were also determined for urban and natural land-cover classes in the region. Fractions were validated using 1m digital photography. GV and NPV Fractions were highly correlated with validation data at all spatial scales, producing a near 1:1 relationship but with a 0.95) including vegetation, water and asphalt, and low emissivity surfaces (roof types, beach sands and senesced grass. Residential and commercial areas showed a general pattern of increasing LST with increasing impervious fraction. Fine scale spatial structure in cover fractions and LST showed important departures from a simple inverse relationship between GV and LST, even at 60m. The results demonstrate the utility of HyspIRI data for urban studies and provide an insight of what will be possible on a global scale with HyspIRI.

Subsurface barrier walls are enjoying a resurgence in popularity as components of site remediation systems largely for two reasons. First, treatment technologies have shown themselves to be incapable of fully managing a large proportion of waste disposal sites, especially large landfills, DNAPL sites, and large industrial plant sites, thus underscoring the importance of site-wide containment technologies such as subsurface barrier walls. The second factor is a parallel advancement in the technologies of barrier wall construction. Advancements, include a variety of geomembrane-based barrier walls, jet grouting techniques, deep soil mixing, and the ability to construct deep barrier walls (greater than 150 feet deep) using interlocking plastic concrete panels. These advancements have led to barrier walls which are not only more impervious, more resistant to chemical attack, and capable of achieving greater depths, but in many cases are less costly than earlier technologies.

Modeling and analyzing dynamic changes of land thermal radiance scenes play an important role in thermal remote sensing. In this paper, the diurnal variation of ground surface thermal scene is mainly discussed. Firstly, based on the land surface energy balance equation, the diurnal variation of land surface temperatures (LSTs) over bare land covers were simulated by an analytical thermal model with second harmonic terms, and the diurnal LST variation of vegetation canopy was simulated using the Cupid model. Secondly, normalized difference vegetation index (NDVI), normalized difference water index (NDWI), and ratio resident-area index (RRI) were used to evaluate the endmember abundance of four land cover types including vegetation, bare soil, impervious and water area, which were calculated...

Montane mainland South East Asia comprises areas of great biological and cultural diversity. Over the last decades the region has overcome an important conversion from traditional agriculture to cash crop agriculture driven by regional and global markets. Our study aims at understanding the hydrological implications of these land use changes at the catchment scale. In 2004, networks of hydro-meteorological stations observing water and energy fluxes were installed in two 70 km2 catchments in Northern Thailand (Chiang Mai Province) and Southern China (Yunnan Province). In addition, a detailed soil surveying campaign was done at the moment of instrument installation. Land use is monitored periodically using satellite data. The Thai catchment is switching from small agricultural fields to large extensions of cash crops. The Chinese catchment is replacing the traditional forest for rubber plantations. A first comparative study based on catchments' geomorphologic characteristics, field observations and rainfall-runoff response revealed the dominant hydrologic processes in the catchments. Land use information is then translated into three different Hydrologic Response Units (HRU): rice paddies, pervious and impervious surfaces. The pervious HRU include different land uses such as different stages of forest development, rubber plantations, and agricultural fields; the impervious ones are urban areas, roads and outcrops. For each HRU a water and energy balance model is developed incorporating field observed hydrologic processes, measured field parameters, and literature-based vegetation and soil parameters to better describe the root zone, surface and subsurface flow characteristics without the need of further calibration. The HRU water and energy balance models are applied to single hillslopes and their integrated hydrologic response are compared for different land covers. Finally, the response of individual hillslopes is routed through the channel network to represent each of the basins. Results from the model are compared to measured catchment-scale water and energy fluxes.

Urban development has expanded rapidly in the Tampa Bay area of west-central Florida over the past century. A major effect associated with this population trend is transformation of the landscape from natural cover types to increasingly impervious urban land. This research utilizes an innovative approach for mapping urban extent and its changes through determining impervious surfaces from Landsat satellite remote sensing data. By 2002, areas with subpixel impervious surface greater than 10% accounted for approximately 1800 km2, or 27 percent of the total watershed area. The impervious surface area increases approximately three-fold from 1991 to 2002. The resulting imperviousness data are used with a defined suite of geospatial data sets to simulate historical urban development and predict future urban and suburban extent, density, and growth patterns using SLEUTH model. Also examined is the increasingly important influence that urbanization and its associated imperviousness extent have on the individual drainage basins of the Tampa Bay watershed. ?? 2005 Elsevier Inc. All rights reserved.

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

Impervious surface coverage keeps spreading in cities. Streets, sidewalks, parking lots and roofs are waterproof, meaning greater amounts of water to channel and treat and higher flood risks during heavy rainfalls. Green roofing can play a key part in addressing this alarming issue. There are three types of green roofs: extensive, semi-intensive and intensive. The extensive green roof technique uses a thin soil covering with a variety of species providing year-round plant coverage. The plants are not necessarily horticultural in which case routine maintenance is minimal. No watering is needed. Usually extensive green roofs create an ecosystem. The semi-intensive green roof technique uses a soil covering of average thickness and serves to create decorative roofing. Although maintenance is moderate, watering is essential. The intensive green roof technique produces a terrace roof garden. Another advantage of green roofs is they increase the life cycle of the sealing. Roof sealing protection may see the span of its life cycle, now at about fifteen years, doubled if the building has a green roof. planning professionals still know very little about green roofing solutions. Yet, green roofing provides unquestionable ecological qualities and thermal and acoustic performance that have proven to be environmentally friendly. Yet France lags behind northern European countries in green roofing. The Germans, Swiss, Austrians, Scandinavians and Dutch have been using the technique for more than twenty years. (A.L.B.)

Two different computer models are tested for their usefulness in predicting the water balance and pressure field surrounding a growing hemispherical In Situ Vitrification (ISV) melt. The melt is centered under the flat surface of a hemisphere of soil contained by an impervious wall. The control volume method is employed for balancing heat, and mass in each model. The soil is considered a porous media; consequently, fluid velocity can be modeled by Darcy`s equation. Both computer models employ grids which adapt to the transient boundary of the growing melt. Computational Grid I (CGI) adapts with the melt boundary by contracting in the radial direction only. In addition to adapting to the melt boundary, Computational Grid II (CGII) also adapts to the liquid-vapor interface which moves outward from the 1,700 C melt in response to the formation of Vapor. CGII has been devised in order to attempt to reduce, at a reasonable CPU cost, the numerical pressure oscillation which arises when the grid is too coarse. A very fine CGI is used as a benchmark to test CGII and a coarser version of CGI. Results from the two CGI and the one CGII cases are presented graphically to illustrate the mass flux of liquid and vapor water and the build-up in pressure as the melt boundary approaches the impermeable wall.

Impervious surfaces are important environmental indicators and are related to many environmental issues, such as water quality, stream health and the urban heat island effect. Therefore, detailed impervious surface information is crucial for urban planning and environment management. To extract impervious surfaces from remote sensing imagery, many algorithms and techniques have been developed. However, there are still debates over the strengths and limitations of linear versus nonlinear algorithms in handling mixed pixels in the urban landscapes. In the meantime, although many previous studies have compared various techniques, few comparisons were made between linear and nonlinear techniques. The objective of this study is to compare the performance between nonlinear and linear methods for...

Mountainous areas of Northern Campania, Southern Italy, are characterized by steep slopes covered with pyroclastic deposits, in form of alternating layers of volcanic ashes and pumices, laying upon a pervious fractured calcareous bedrock, in some cases covered by a thin layer of impervious weathered ashes. Slope inclination is often larger than internal friction angle of such ashes (around 38°), thus equilibrium is assured by the contribution of apparent cohesion due to soil suction in unsaturated conditions. That is why, during intense and persistent rainfall events, when soil approaches saturation and consequently suction decreases, shallow landslides are frequently triggered. The physical characteristics of involved soils are such that landslides often evolve in form of debris flows, which can cause huge damages to buildings and infrastructures and, in some cases, even casualties. Understanding the role played by rainfall infiltration processes is essential to develop reliable models of slope response. To this aim, for the slope of Cervinara, where a large debris flow occurred in the past, laboratory infiltration tests and in situ monitoring are being carried out. Infiltration and evaporation tests are performed on artificial deposit reconstituted in a model slope subjected to controlled uniform rainfall, with various inclinations and bottom boundary conditions. The coupled values of soil suction and water content, observed during the experiments, have allowed defining the water retention curves experienced by the pyroclastic soil in the model slope. The performed infiltration experiments have been simulated with a mathematical model based on the integration of Richards equation with the finite volumes technique. The use of the retention curves obtained from the experiments allowed to build up reliable mathematical models of infiltration also in the case of layered slopes. Recently at the slope of Cervinara an automatic in situ monitoring station has been set up. The data of soil water content and suction collected during one year allow distinguishing different hydraulic behaviour of soil layers, and estimating soil hydraulic characteristic curves. In particular, the water retention curves derived from in situ monitoring show some differences compared to that observed in the infiltration tests on model slopes. The use of the in situ retention curves from the monitoring will allow better calibration of mathematical models of infiltration also in the case of complex geometry.

The construction of artificial wetlands for wastewater treatment often requires impermeable liners not only to protect groundwater resources but also to ensure that there is adequate water in the wetland to support appropriate aquatic life, particularly wetland vegetation. Liners or relatively impervious site soils are very important to the success of constructed treatment wetlands in areas where ground water levels are typically close to the ground surface. This study, carried out at the Olentangy River Wetland Research Park, investigated the use of FGD material from sulfur scrubbers as a possible liner material for constructed wetlands. While several studies have investigated the use of FGD material to line ponds, no studies have investigated the use of this material as a liner for constructed wetlands. They used experimental mesocosms to see the effect of FGD liner materials in constructed wetlands on water quality and on wetland plant growth. This paper presents the results of nutrient analyses and physicochemical investigation of leachate and surface outflow water samples collected from the mesocosms. Plant growth and biomass of wetland vegetation are also included in this paper. First two year results are reported by Ahn et al. (1998, 1999). The overall goal of this study is the identification of advantages and disadvantages of using FGD by-product as an artificial liner in constructed wetlands.

The research presented was conducted as part of Watershed Watch, a two-week hands-on summer program for undeclared entry-level undergraduates, designed to recruit and retain students in Science, Technology, Engineering, and Mathematics (STEM) disciplines. The research presented here was conducted on cypress knees of different ages from the campus of Elizabeth City State University in northeastern North Carolina. Samples were collected from Bald Cypress (Taxodium distichum) knees and thin sections were cut from the distal, medial, and proximal regions of each knee. Three specimens of each of young and old knees were analyzed. Structural differences in the location and amount of wood (secondary xylem), parenchyma, and aerenchyma tissues were compared in order to determine if both younger and older knees function as pneumatophores, and if only the younger knees are capable of providing oxygen to roots in waterlogged soils. Our findings include: younger knees have the most aerenchyma tissue (living cells associated with air canals) and a thinner bark (likely pervious) on the distal tips. The older knees are more woody with distinct growth rings, exhibit less aerenchyma tissue, and have a much thicker (likely impervious) bark at the distal tip. The conclusion regarding the purpose of cypress knees is that the younger knees likely function as aerating organs (peumatophores) for the growing roots tips, while the older knees have reduced amounts of aerenchyma tissue and a thicker bark, and therefore may lose the ability to function as an aerating organ for the older roots.

Increased urbanization results in a larger percentage of connected impervious areas and can contribute large quantities of stormwater runoff and significant quantities of debris and pollutants (e.g., litter, oils, microorganisms, sediments, nutrients, organic matter, and heavy me...

Increased urbanization has increased the amount of directly connected impervious area that results in large quantities of stormwater runoff. This runoff can contribute significant amounts of debris and pollutants to receiving waters. Urban watershed managers often incorporate b...

This project investigated the use of constructed wetlands and retention ponds for decreasing microbial concentrations from urban stormwater runoff. Increased urbanization has resulted in a larger percentage of impervious areas which cause large quantities of stormwater runoff an...

Oct 4, 2012 ... Identifying relations between stream ecological condition and urban ... to effectively address planning and management needs in such areas. ... landscape pattern, land cover, land use, water quality, impervious surface ...

Excess stormwater runoff can cause serious pollution, habitat degradation and flooding in cities where growth in impervious surface area (such as pavement, buildings, etc.) has created a situation where stormwater runoff routinely exceeds the normal capacity of natural and constr...

Inter-generationally prudent management of watershed resources will require attention to the interdependence between shifting landuse distributions and their effects on watershed hydrology. Development and increased proportion of impervious surface area has been found to alte lan...

A new management policy regarding road runoff was proposed in 2002 by the Swiss Federal Office for the Environment (FOEN). This new concept is based on the diffuse infiltration of road runoff into embankment slopes, where soils will filter particles and contaminants. The shoulder lying between road surface and infiltration slopes must be impervious in order to maximise the amount of water reaching the slope and avoid losses in the road structure. The implementation of this new concept should lower the impact of roads on the environment, improve aquifer recharge and reduce construction costs. The Swiss Federal Road Office (FedRO) decided to carry out real-scale investigations regarding this new policy and thus commissioned the GEOLEP to design, build, and test 5 different shoulder structures. This paper presents the results of a 2-years survey of infiltration processes in these shoulders to establish the best performing structure. The first three shoulders were overlaid with 5 cm of gravel mixed with humus, gravel mixed with clay, and seeded with lawn, respectively. The latter two had impervious layers located 26 cm deep: the road bituminous basement (road base) was prolonged and coated with bitumen in the first case, and a sodic-bentonite geotextile was used in the second. Both were covered with gravel. All shoulders were equipped with basal collecting devices that measured hydraulic fluxes seeping through the shoulders. In total, 112 natural precipitations and 3 artificial events were monitored. Artificial events mimicked known transitory regimes (thunderstorms) or were performed with constant regime. The goal was to effectively assess infiltration processes in shoulders. Results showed that shoulders made of gravel and humus or lawn were highly ineffective (only 30 to 40% of runoff is conducted to the infiltration slope). Gravel and clay was more efficient with a proportion of approximately 60%. The shoulder with prolonged road base showed similar results since the bituminous coating was in fact rather permeable. The best results were exhibited by the shoulder waterproofed with bentonitic geotextile, which allowed no water to penetrate. This material already proved to be very powerful in groundwater catchments. The authors thus proposed a combination of sodic-bentonite geotextile covered by a gravel and clay mixture. This would be the most efficient shoulder: it will convey all the runoff to infiltration slopes, thereby optimising its filtration, which in turn will enhance environmental conditions in the vicinity of roads. PMID:19759460

Stormwater infiltration measures such as soakaways are expected to be part of future urban drainage systems. However, few studies exist on the effect of extensive stormwater infiltration through soakaways on the overall urban water system, including sewers and groundwater, at city catchment scale. In particular such estimates have not been made in real urban settings with multiple physical and structural constraints. This paper presents a methodology for conducting such an analysis, and provides quantitative estimates of the effects on the urban water flows. Using an interdisciplinary, three-step approach that employed GIS analyses and physically distributed, dynamic pipe flow modelling in an iterative manner, this study estimates the impact of infiltration on combined sewage overflows (CSOs) in a 3km2 urban catchment in Copenhagen. The first step was the creation of a baseline scenario. The second step led to a potential infiltration scenario where 65% of the total impervious area was connected to soakaways,and resulted in an estimated reduction in annual sewage overflow volume of 68%. This scenario was then further developed in the third step by adding groundwater constraints, which formed a more realistic scenario where only 8% of the impervious area was connected to soakaways and the reduction in CSO volume was 24%. The potential and realistic scenarios were modelled both with hydraulic coupling between soakaway and sewer, and as fully disconnected. Results show that infiltration is constrained mainly by the quality of the stormwater runoff from roads and limited land availability in the potential infiltration scenario, and by low-permeable soils and a problematically high groundwater level in the realistic infiltration scenario. The hydraulically coupled model gives higher CSO volume than the fully disconnected model for the potential infiltration scenario, whereas no difference is seen between these two models in the realistic infiltration scenario. The effect of infiltration on combined sewer overflows isthus expected to be limited in the case study area. General conclusions are that groundwater constraints are important to consider when evaluating the potential of infiltration-based stormwater management, and that it is important to include the hydraulic coupling between soakaways and sewers in models if soakaways are expected to give overflow to the sewers.

Unchecked human development has ravaged the region between Dominical and Uvita, Costa Rica. Much of the development transition has been driven by tourism and further foreign direct investment in residential, service and commercial enterprises. The resulting land-use/land-cover change has removed traditional forest cover in exchange for impervious surfaces, physical structures, and bare ground which is no longer mechanically supported by woody vegetation. Combined with a tropical climate, deeply weathered soils and lithography which are prone to erosion, land cover change has led to an increase in slope failure occurrences. Given the remoteness of the Dominical-Uvita region, its rate of growth and the lack of monitoring, new techniques for monitoring land use and slope failure susceptibility are needed. Two new indices are presented here that employ a Digital Elevation Model (DEM) and widely available Landsat imagery to assist in this endeavor. The first index, or Vegetation Influenced Landslide Index (VILI), incorporates slope derived from a DEM and Lu et al.'s (2007) Surface Cover Index to quantify vegetative cover as a means of mechanical stabilization in landslide prone areas. The second index, or Slope Multiplier Index (SMI), uses individual Landsat data bands and basic Landsat band ratios as environmental proxies to replicate soil, vegetative and hydrologic properties. Both models achieve accuracy over 70% and rival results from more complicated published literature. The accuracy of the indices was assessed with the creation of a landslide inventory developed from field observations occurring in December 2007 and November 2008. The creation of these indices represents an efficient and accurate way of determining landslide susceptibility zonation in data poor areas where environmental protection practitioners may be overextended, under-trained or both.

The study is carried out in a plot of 1330 m2 located on the experimental catchments of Draix (Alpes de Haute Provence, France). Approximately two thirds of the surface are made of a bare marly zone (marls of Callovo-Oxfordien called " Terres Noires "). The upper part is covered by a shrubby vegetation on a soil whose depth does not exceed 70 cm. The plot outlet is equipped with a V-notch weir and a stage recorder. Experiments of chemical and isotopic water tracing have been carried out on this site to (1) provide information about the flow processes (in relation with field observations and hydrometric measurements), (2) to test the relevance of isotope tracers to define at this scale the residence time distribution of new water, (3) to compare the results with those obtained using an hydrological model. For these objectives, a further equipment was added on the plot in spring 2001 : sequential sampler for the collection of discrete rainfall increments (increments of 3 mm), porous ceramic cups for the sampling of soil water and automatic sampler at the outlet. 3 flood events were sampled between the 4th and 25th July 2001. The rainfall amounts were 28.4 mm, 54.2 mm and 29.2 mm producing peak flows of 5.7 l/s, 16.4 l/s and 13.9 l/s, respectively. Despite the physical context (steep slope, impervious material), the discharge coefficients donSt exceed 30 %. This result emphasises the impact of the soil layer (and perhaps the marl itself) on water storage. The storage time and the delay of water transfer are studied using water tracing. Water samples were analysed for major species, dissolved organic carbon and oxygen-18. The first results confirm the important role of the soil on water quality. The chemographs show that a pre-event water contributes to the flow. This impact on water quality may be explained by a rapid movement of water through the subsurface into the soil macropores. The analysis of the input-output relation for isotope concentrations and the application of the EMMA approach using chemical tracers allow to characterise the variation of the hydrological behaviour between 3 successive flood events.

The Kinnickinnic River in west-central Wisconsin is classified as a state outstanding resource water, and is a premiere Midwest trout stream, with a self-sustaining brown trout population. River Falls, Wisconsin (population 10,000), located in the heart of the Kinnickinnic River watershed, is developing rapidly because of its proximity to the Minneapolis/St. Paul, MN metropolis. With increasing residential, commercial, and industrial development, concerns about urban stormwater impacts on the Kinnickinnic River are also increasing. These impacts include higher stream flows, thermal pollution, and sedimentation, all of which pose threats to trout and aquatic habitat. In response to the concern about thermal pollution, the Kiap-TU-Wish Chapter of Trout Unlimited established a temperature monitoring network in 1992, at four Kinnickinnic River locations throughout River Falls. Data-logging thermometers continuously record stream temperatures at 10-minute intervals, clearly demonstrating stormwater-induced thermal changes. Rapidly-increasing stream temperatures are often evident at locations downstream from stormwater outfalls during summer rainfalls, and stormwater temperatures may exceed 80 F. The thermal impacts of two small municipal hydropower impoundments have also been documented. Storm event-based composite sampling of residential, commercial, and industrial areas of River Falls (1992) suggests that these areas are highly susceptible to soil erosion, with sediment concentrations greater than the NURP average. Concentrations of some sediment-associated metals are also high. In 1994, River Falls developed a stormwater management plan for the Kinnickinnic River. Plan recommendations include a limitation of 12% impervious area within the city, proper detention pond design to mitigate thermal impacts, stringent erosion control ordinances, additional stormwater BMP`S, and increased public awareness and involvement.

Rooftops in urban areas comprise a substantial portion of the total land surface area, and their physical properties are important determinants of the urban environment. Black impervious rooftops contribute to heat island effects and combined sewage-stormwater overflows. Green rooftops can be used to mitigate these environmental problems if implemented on a wide scale. This study used a simple energy balance model to study the impact of roof types on urban heat island and building energy consumption rates. The model included equations for shortwave and longwave radiation as well as convective, latent and conductive heat fluxes. A temperature gradient model with a wind-dependent coefficient was used to measure convection. Latent heat flow for green roofs was modelled using the Bowen ratio. An equilibrium model was used to determine energy balance. Convection coefficients and the Bowen ratio were determined using a hierarchical approach applied to field data for 3 control and 3 green roofs monitored at Pennsylvania State University. The model showed good agreement with field data. A calibrated control roof model and data were then used to determine the performance of green roofs compared to white roofs. Results showed that in order to maintain their effectiveness, white roofs require regular washing, as their effectiveness drops due to natural weathering and soiling. The experiments suggested that green roofs cool as effectively as white roofs, with the added benefit of maintaining lower temperatures in the rooms beneath the roofs. It was concluded that although green roofs are more expensive than white roofs, the benefits of green roofs make them more desirable and cost-effective. White roofs offer surface cooling benefits, but require burdensome maintenance to be fully effective. 12 refs., 6 figs.

With an unprecedented projection of population and urban growth in the coming decades, assessment of the long-term hydrologic impacts of land use change is crucial for optimizing management practices to control runoff and non-point source (NPS) pollution associated with sustainable watershed development. Land use change, dominated by an increase in urban/impervious areas, can have a significant impact on water resources. Non-point source (NPS) pollution is the leading cause of degraded water quality in the US and urban areas are an important source of NPS pollution. Most planners, government agencies, and consultants lack access to simple impact-assessment tools despite widespread concern over the environmental impacts of watershed development. Before investing in complex analyses and customized data collection, it is often useful to utilize simple screening analyses using data that are already available. In this paper, we discuss such a technique for long-term hydrologic impact assessment (L-THIA) that makes use of basic land use, soils and long-term rainfall data to compare the hydrologic impacts of past, present and any future land use change. Long-term daily rainfall records are used in combination with soils and land use information to calculate average annual runoff and NPS pollution at a watershed scale. Because of the geospatial nature of land use and soils data, and the increasingly widespread use of GIS by planners, government agencies and consultants, the model is integrated with a Geographic Information System (GIS) that allows convenient generation and management of model input and output data, and provides advanced visualization of the model results. An application of the L-THIA/NPS model on the Little Eagle Creek (LEC) watershed near Indianapolis, Indiana is illustrated in this paper. Three historical land use scenarios for 1973, 1984, and 1991 were analyzed to track land use change in the watershed and to assess the impacts of land use change on annual average runoff and NPS pollution from the watershed and its five sub-basins. Results highlight the effectiveness of the L-THIA approach in assessing the long-term hydrologic impact of urban sprawl. The L-THIA/NPS GIS model is a powerful tool for identifying environmentally sensitive areas in terms of NPS pollution potential and for evaluating alternative land use scenarios to enhance NPS pollution management. Access to the model via the INTERNET enhances the usability and effectiveness of the technique significantly. Recommendations can be made to community decision makers, based on this analysis, concerning how development can be controlled within the watershed to minimize the long-term impacts of increased stormwater runoff and NPS pollution for better management of water resources.

Accurately estimating impervious surfaces is of considerable importance towards understanding human impacts on the environment. In this article, a sequential multiprocess model is presented to estimate the distribution of impervious surfaces using Landsat Enhanced Thematic Mapper Plus (ETM+) satellite imagery. Unlike typical single-thread classification processes, the multiprocess model consists of a series of classification steps. By separating the classification task into several subtasks of variable difficulty, multiple classifiers are integrated while adapting to different levels of complexity. The results show statistically significant improvements for the proposed model. An interesting finding is the uneven distribution of simple classifiers in either highly rural or suburban/urban a...

This study's objectives were to (1) determine the relative contribution of impervious surface individual components by collecting digital information from high-resolution imagery, 1-meter or better; and to (2) determine which of the more advanced techniques, such as spectral unmixing or the application of coefficients to land use or land cover data, was the most suitable method that could be used by State and local governments as well as Federal agencies to efficiently measure the imperviousness in any given watershed or area of interest.\\r\

Differences in rock properties are reflected in landscape morphology and all else equal, harder rock should produce steeper hillslopes. While this concept is oft-stated, it is seldom characterized. In the humid, soil-mantled mountainous landscape of the Oregon Coast Range (OCR), steep hillslopes are sculpted in rhythmically bedded sandstones of the Eocene Tyee Formation where subtle variations in rock properties appear to have profound geomorphic implications. Numerous resistant beds appear unfractured and impervious to soil production mechanisms such as tree root activity and mountain beaver burrowing. Here we present observations from the field, thin section petrology, rock mechanics, and airborne lidar to characterize minor grain-scale differences in rock properties and their influence on rock strength and fracture density and thus hillslope processes and morphology. In Franklin Creek watershed, bands of cliff-forming resistant sandstone crop out in ~1-10m thick swaths. These cliff-forming bands are absent in the adjacent Harvey watershed due to the local structural setting. Harvey watershed is characterized by 'classic' OCR topography -repeating ridge and valley sequences, while Franklin watershed exhibits hanging valleys and changes in slope and curvature above the cliff-forming beds. Although calcite-cemented sandstone beds are reported in the literature for the Tyee Fm, we find no evidence for calcite in the resistant sandstone beds. Instead, preliminary petrographic analysis suggests that diagenetic clay rims in the resistant rock types may account for their higher strength. Preliminary point load and indirect tensile strength tests comparing 'typical' and 'resistant' beds of the Tyee Formation show a significant difference, with indirect tensile strength measurements of 0.83 ± 0.1 MPa for typical rock and 2.06 ± 0.7 MPa for the resistant rock type. Using airborne lidar data we explore how these resistant beds modulate topography. Soil production in much of the OCR is driven by tree turnover and root growth that generates a topographic signature via pit and mound features. To determine if resistant rock swaths lack this biotic signature, we compared topographic profiles from typical soil-mantled and resistant rock settings. To quantify how hillslopes adjust their form with and without resistant rock beds, we calculated distributions of gradient, hillslope curvature and roughness in both catchments. We also test whether a critical bed thickness or slope position of the resistant beds is required for persistent base level and therefore controls the presence or absence of hanging valleys. Based on field observations in multiple watersheds in the Oregon Coast Range, the resistant rock type has a lower fracture density than the typical rock type, and does not produce soil. At the watershed scale this resistant rock type creates knickpoints, leading to the formation of hanging valleys above and over-steepened hillslopes below, suggesting that rock properties and fracture density may be a first order control on soil production and hillslope processes.

The experimental results on the imperviousness of the silica aerogels against various organic solvents and acids, are reported. Various types of hydrophobic silica aerogels were prepared using methyltrimethoxysilane (MTMS); tetraethoxysilane (TEOS) with ethyltriethoxysilane (ETES) and phenyltriethoxysilane (PTES) as co-precursors. The organic solvents used were: methanol, ethanol and acetone, and the acids used were: hydrochloric acid (HCl), nitric acid (HNO3) and sulphuric acid (H2SO4). The imperviousness of the aerogels against these solvents and acids were tested with the variation of the percentage of organic solvents and acids in water from 10 to 100% and was characterized by the contact angle measurements. It was observed that in all the cases, the contact angle decreased with an increase in the percentage of solvent in water. While there was no absorption of the solvent up to 20% in water by the ETES and PTES modified aerogels, the MTMS-based aerogels showed the imperviousness up to 60% of the solvent in water. The MTMS aerogels were also impervious against all the three acids up to 100%, while the ETES and PTES modified aerogels could withstand only up to 80% of acids in water.

Cities exhibit unique spatial patterns, and thus a distinctive heterogeneity. At different scales of influence, they introduce changes in the physical properties of the natural environment, as the diffusion of impervious surfaces. While climate change is expected to increase the frequency of hazard...

Although urbanization has a major impact on watershed hydrology, there have not been many studies to quantify how basic hydrological relationships are altered by the addition of impervious surface under controlled conditions. The USDA-ARS and USEPA have jointly initiated a pilot program to study the...

PV systems on buildings get more funds than open-field PV systems. This is an attempt to prevent urbanization and impervious surface changes. Agricultural buildings are an exemptions. As a result, hay sheds and tool sheds are getting more attention than ever before.

Laboratory experiments show that preferential paths develop through saturated impervious clay bodies. A procedure to integrate gas transmission discontinuities into a general THM formulation is described. The technique has been incorporated into a general purpose FE THM code (CODE_BRIGHT) and it has...

Glioblastoma multiforme (GBM) remains frustratingly impervious to any existing therapy. We have previously shown that GBM is sensitive to recognition and lysis by ex vivo activated gamma delta T cells, a minor subset of lymphocytes that innately recognize autologous stress-associated target antigens...

An improved interface configuration for use between adjacent elements of a fuel cell stack. The interface is impervious to gas and liquid and provides resistance to corrosion by the electrolyte of the fuel cell. A multi-layer arrangement for the interface provides bridging electrical contact with a hot-pressed resin filling the void space.

Development that increases the impervious surface in a watershed causes excess storm water runoff (SWR) that has been identified as a major contributor to stream and riparian habitat degradation. Reduction of storm water runoff can be achieved through establishment of a number of...

Baked, impervious carbon articles may be produced by impregnating carbonaceous materials with a thermosetting epoxy resin and curing with dicyanamide solution. Data are presented on the pot life of various epoxy impregnant compositions and on the properties of impregnated graphite bars. (D.L.C.)

Evapotranspiration (E) and runoff (RT) was modeled for the island of Sjælland (?7330 km2) in Denmark at multiple spatial scales encompassing agricultural, forest and urban land surfaces. National data were used to represent spatial variations in climate, soil properties and lower boundary conditions, and the EOS/MODIS Normalized Difference Vegetation Index (NDVI) was used to map (a) the temporal development in leaf area index for agricultural fields, (b) a dynamic “canopy” coefficient (Kc) of forests being scaled between its minimum and maximum values for use in the FAO Penman–Monteith equation, and (c) the impervious land cover fraction of urban regions. At field level, the use of local-scale model parameters, NDVI time series and site-specific methodologies to simulate E of the 3 major land surface types (agricultural land, forests and urban regions) explained 67–79% of the observed variability in eddy covariance latent heat fluxes. The “effective” spatial resolution needed to adopt local-scale model parameters for spatial-deterministic hydrological modeling was assessed using a high-spatial resolution (30 m) variogram analysis of the NDVI. The use of the NDVI variogram to evaluate land surface heterogeneity is based on the assumption that sub-class soil heterogeneity can be indirectly represented by the observed spatial variations in NDVI due to its close affiliation with vegetation growth, soil water uptake and evapotranspiration. Multiple spatial resolution water balance simulations were compared to validate the identified effective spatial resolution (500 m) model representation of land cover, NDVI and drainage pattern. Simulated RT of 30 catchments were compared with the fast-flow component of stream discharge data (Q ? Qb) which is insensitive to groundwater abstraction and most sensitive to the spatial land surface representation. A good agreement was observed in the timing and size of peak flows in catchment dominated by agricultural, forest and urban land uses in periods when E has important control on the water balance and soil water percolation to groundwater is negligible (Days 125–300). The presence/absence of pipe drains, urban surface runoff and forest parameterization cause very large differences in the water balance of agricultural, forest and urban regions. The results show that the use of local-scale standard model parameters and NDVI time series representing agricultural, forest and urban land surfaces in physically based hydrological modeling makes it possible to reproduce much of the observed variability (48–73%) in stream flow (Q ? Qb) when data and modeling is applied at an effective spatial resolution capable of representing land surface heterogeneity. In order to further improve the results, (1) advanced spatial parameterization methods are needed to improve the modeling of bare soil E of agricultural fields, (2) the impact of local conditions, such as tree age and nutrient levels, should be used to parameterize the maximum Kc used for forest E modeling, (3) high accuracy remote sensing based estimation of vegetation parameters is particularly important during sparsely vegetated conditions, and (4) the use of component stream flow data to evaluate the physical consistency of spatial-deterministic models appears to be feasible and should be further explored.

Shallow Landslides are one of the most important causes of loss of human life and socio-economic damage related to the hydro-geological risk issues. The danger of these phenomena is related to their speed of development, the diffculty of foreseeing their location, and the high density of individual phenomena, whose downhill trajectories have a relevant probability of interfering with urbanized areas. Research activity on precipitation-induced landslides has focused mainly on developing predictive understanding of where and when landslides are likely to occur. Nevertheless, some major aspects that may be related to activation of landslides have been poorly investigated. For instance, landslide susceptibility zones are generally predicted assuming constant thickness of soil over an impervious bedrock layer. Nevertheless, recent studies showed subsurface topography could be a first order control for subsurface water-flow dynamics, because of the effects of its own irregular shape. Tromp-van Meerveld and McDonnell (2006) argued that connectivity of patches of transient saturation were a necessary prerequisite for exceeding the rainfall threshold necessary to drive lateral flow. Connectivity - "how the hillslope architecture controls the filling and spilling of isolated patches of saturation" (Hopp and McDonnell, 2009) - appears to be a possible unifying concept and theoretical platform for moving hillslope and watershed hydrology forward. Connectivity could also have important implications on triggering of shallow landslides, because the particular shape of bedrock may limit the water-flow downhill. Here we present a number of virtual numerical experiments performed to investigate the role of bedrock shape and hillslope gradient on pore-water pressure development. On this purpose, our test is represented by the subsurface topography of the Panola Experiment Hillslope (PEH). That is because scientific literature on PEH provides substantial documentation about the role of bedrock layer on subsurface water-flow dynamics. We also exploit the concept of Downslope Index (DWI) (Hjerdt et al., 2004) and Upslope Contributing Area (UCA) as indicators of the areas more susceptible to landslide. The results indicate that bedrock shape influences the max pore-water pressure, even with different hillslope gradients; meanwhile, hillslope gradient affects the persistence-time of the max pore-water pressure. Moreover, results suggest DWI as an useful index to improve the capability of the very-used SHALSTAB model to assess for landslide susceptibility areas.

This study develops an integrated approach to assess climate change and urbanization impacts on adaptation strategies in watersheds. We considered the two adaptation strategies for two small watersheds in Korea: the redevelopment of an existing reservoir and the reuse of highly treated wastewater treatment plant (WWTP) effluent. Climate change scenarios were obtained by statistically downscaling the predicted precipitation and temperature with a global climate model (A1B and A2), and urbanization scenarios were derived by estimating the impervious area ratios with an impervious cover model. With the climate change and urbanization scenarios, we used the Hydrological Simulation Program-Fortran model to derive the flow and biochemical oxygen demand (BOD) concentration (conc.) duration curves...

In a high temperature solid oxide fuel cell (SOFC), the deposition of an impervious high density thin layer of electrically conductive interconnector material, such as magnesium doped lanthanum chromite, and of an electrolyte material, such as yttria stabilized zirconia, onto a porous support/air electrode substrate surface is carried out at high temperatures (approximately 1100{sup 0}-1300{sup 0}C) by a process of electrochemical vapor deposition. In this process, the mixed chlorides of the specific metals involved react in the gaseous state with water vapor resulting in the deposit of an impervious thin oxide layer on the support tube/air electrode substrate of between 20-50 microns in thickness. An internal heater, such as a heat pipe, is placed within the support tube/air electrode substrate and induces a uniform temperature profile therein so as to afford precise and uniform oxide deposition kinetics in an arrangement which is particularly adapted for large scale, commercial fabrication of SOFCs.

The authors have investigated the behavior of Cd and Pb salts toward cement-based solidification using TCLP leaching tests, conduction calorimetry, and solid-state NMR as a function of time. Concentrations of Cd in leachates are very low, while Pb concentrations are considerably higher and would represent a serious threat to groundwater. The Cd/cement system involves Cd(OH){sub 2}, while provides nucleation sites for precipitation of calcium silicate hydrate (C-S-H) gel and calcium hydroxide, resulting in Cd being in the form of the insoluble hydroxide with a very impervious coating. On the other hand, the Pb/cement system involves hydroxide, sulfate, and nitrate mixed salts, which retard cement hydration reactions by forming an impervious coating around cement clinker grains. However, as pH in the cement pore waters undergoes fluctuations during the progress of hydration, the Pb salts undergo solubilization and reprecipitation on leachable surfaces of the cement matrix.

Numerous uranium veins occupy fractures and faults in brittle Proterozoic gneisses along the east central Front Range of Colorado. The deposit size correlates with the density and localization of brittle fracture. The largest deposit, the Schwartzwalder, is explained by a singular configuration of complexly broken, deep-reaching brittle gneisses between impervious schists. The gneisses are described as being derived from volcanic rocks, shales, and chemical sediments, including iron, quartz and sulphide formations.-G.J.N.

A process is described for curing or hardening an organic synthetic resin coating on one face of an impervious sheet by electron-induced cross- linking of the resin by an unsaturated monomer. The electrons are of 50 to 250 kev. The monomer is vinyl carbazole, diallylphthalate, or styrene, and the polyester resin is in liquid form prior to irradiation. Examples are given. (R.E.U.)

An internal combustion engine is described that has walls delimiting the working space or spaces of the internal combustion engine, in which a hydrogen-impervious, encapsulated metal hydride storage device is provided which is in heat-conducting contact with these walls; the interior of the encapsulation is adapted to be selectively connected to a source of hydrogen and/or to a separate further hydrogen storage device.

This document describes a light weight zinc electrode made of a sintered mat of copper metal coated graphite fibers, a composite material of zinc active material, and a hydrogel dispersed in a solid, impervious, inert polymer matrix. The composite material surrounds the individual copper metal coated graphite fibers of the sintered mat which support the composite material and provide paths of electrical conductivity throughout the composite material.

Semi-arid regions are experiencing disproportionate increases in human population and land transformation worldwide, taxing limited water resources and altering nitrogen (N) biogeochemistry. How the redistribution of water and N by urbanization affects semi-arid ecosystems and downstream water quality (e.g. drinking water) is unclear. Understanding these interactions and their feedbacks will be critical for developing science-based management strategies to sustain these limited resources. This is especially true in the US where some of the fastest growing urban areas are in semi-arid ecosystems, where N and water cycles are accelerated, and intimately coupled, and where runoff from urban ecosystems is actively managed to augment a limited water supply to the growing human population. Here we synthesize several ongoing studies from the Tucson Basin in Arizona and examine how increasing urban land cover is altering rainfall-runoff relationships, groundwater recharge, water quality, and long range transport of atmospheric N. Studies across 5 catchments varying in impervious land cover showed that only the least impervious catchment responded to antecedent moisture conditions while hydrologic responses were not statistically related to antecedent rainfall conditions at more impervious sites. Regression models indicated that rainfall depth, imperviousness, and their combined effect control discharge and runoff ratios (p transport of N and N emissions from Tucson are being transported and deposited at high elevation in areas that recharge regional groundwater. Combined, our findings suggest that urbanization in semi-arid regions results in tradeoffs in the redistribution of water and N that have important implications for water management and sustaining water quality.

We analyzed data from riffle and snag habitats for 39 small cold water streams with different levels of watershed urbanization in Wisconsin and Minnesota to evaluate the influences of urban land use and instream habitat on macroinvertebrate communities. Multivariate analysis indicated that stream temperature and amount of urban land use in the watersheds were the most influential factors determining macroinvertebrate assemblages. The amount of watershed urbanization was nonlinearly and negatively correlated with percentages of Ephemeroptera-PlecopteraTrichoptera (EPT) abundance, EPT taxa, filterers, and scrapers and positively correlated with Hilsenhoff biotic index. High quality macroinvertebrate index values were possible if effective imperviousness was less than 7 percent of the watershed area. Beyond this level of imperviousness, index values tended to be consistently poor. Land uses in the riparian area were equal or more influential relative to land use elsewhere in the watershed, although riparian area consisted of only a small portion of the entire watershed area. Our study implies that it is extremely important to restrict watershed impervious land use and protect stream riparian areas for reducing human degradation on stream quality in low level urbanizing watersheds. Stream temperature may be one of the major factors through which human activities degrade cold-water streams, and management efforts that can maintain a natural thermal regime will help preserve stream quality.

More than 50% of the world population now lives in urban and suburban areas. The rate of urbanization in the world is expected to continue to accelerate in the near future. As urban areas expand by transforming the surrounding landscape into impervious surface, the changes of urban land cover (ULC) have significant implications for wide range consequences. Monitoring changes in large urban areas becomes increasingly important. The U.S. Geological Survey (USGS) recently published the National Land Cover Database (NLCD) 2006 products including land cover and percent impervious surface area (ISA) for the conterminous United States (CONUS). The percent ISA, which represents the fraction of impervious area in a 30 m grid, was estimated using regression tree algorithms with both Landsat and nighttime lights imagery. Generally, the approach comprises four major procedures: creating a training dataset, modeling a synthetic impervious surface, comparing model outputs for optimal selection and final product clean up. The ISA product was used to define four different ULC types by categorizing percent ISA and quantitatively determining the extent of ULC. We analyzed 2001 and 2006 imperviousness variations to summarize two areal increments: ISA, which calculates the area of imperviousness proportion in every 30 m pixels, and urban area, which totals the number of 30 m pixels that contain any impervious surface. The new ISA in 2006 increases 4.1% (4095 km2) from the 2001 base amount across the CONUS. The growth of ISA reached approximately 819 km2 per year during the period. The total ISA in 2006 reached 103,615 km2, which is slightly smaller than the state of Kentucky. The new urban area in 2006 was 12,365 km2 and the total urban area reached 500,153 km2, which is close to the size of California and Indiana combined. To analyze the interactions between ULC change and climate systems, we used both the gridded climate data from the Parameter-elevation Regressions on Independent Slopes Model (PRISM) dataset and NLCD ISA product. Mean annual precipitation, mean annual minimum temperature (Tmin), and mean annual maximum temperature (Tmax) from 1980 to 2010 were converted to a raster format. A standardized anomaly method was used to calculate climatic anomalies by A(t)=(X(t)-Xmean)/? , where A(t) is the standardized anomaly of a given quantity X (e.g., mean annual Tmin) in a specific year t, Xmean is the long time mean, and ? is the standard deviation. The means of annual Tmin in the periods of 1995-2000 and 2001-2006 were averaged in the newly urbanized areas that emerged after 2001. The average in the urbanized time period (2001-2006) is about 0.3 °C higher than the average in the pre-urbanized time (1995-2000). Similarly, in the new urban areas, the six year averages of standardized anomaly of Tmin were 0.12 and 0.52 in the periods of 1995-2000 and 2001-2006, respectively, indicating a larger anomaly due to ULC change. The land cover change characterized by urbanization apparently affects surrounding ecological system conditions and imposes a significant forcing function on the climate system.

Stream network density exerts a strong control on hydrologic processes in watersheds. Over land and through soil and bedrock substrate, water moves slowly and is subject to chemical transformations unique to conditions of continuous contact with geologic materials. In contrast, once water enters stream channels it is efficiently transported out of watersheds, reducing the amount of time for biological uptake and stream nutrient processing. Therefore, stream network density dictates both the relative importance of terrestrial and aquatic influences to stream chemistry and the residence time of water in watersheds, and is critical to modeling and empirical studies aimed at understanding the impact of land use on stream water quantity and quality. Stream network density is largely a function of the number and length of the smallest streams. Methods for mapping and measuring these headwater streams range from simple measurement of stream length from existing maps, to detailed field mapping efforts, which are difficult to implement over large areas. Confounding the simplest approaches, many headwater stream reaches are not included in hydrographical maps, such as the U.S. National Hydrography Dataset (NHD), either because they were buried during the course of urban development or because they were seen as smaller than the minimum mapping size at the time of map generation. These "missing streams" severely limit the effective analyses of stream network density based on the NHD, constituting a major problem for many efforts to understand land-use impacts on streams. Here we report on research that predicts stream presence and absence by coupling field observations of headwater stream channels with maximum entropy models (MaxEnt) commonly implemented in biogeographical studies to model species distributions. The model utilizes terrain variables that are continuously accumulated along hydrologic flowpaths derived from a 10-m digital elevation model. In validation, the model correctly predicts the presence of 91% of all 10-m stream segments, and rarely miscalculates tributary numbers. We apply this model to the entire Potomac River Basin (37,800 km2) and several adjacent basins to map stream channel density and compare our results with NHD flowline data. We find that NHD underestimates stream channel density by a factor of two in most sub watersheds and this effect is strongest in the densely urbanized cities of Washington, DC and Baltimore, MD. We then apply a second predictive model based on impervious surface area data to map the extent of stream burial. Results demonstrate that the extent of stream burial increases with decreasing stream catchment area. When applied at four time steps (1975, 1990, 2001, and 2006), we find that although stream burial rates have slowed in the recent decade, streams that are not mapped in NHD flowline data continue to be buried during development. This work is the most ambitious attempt yet to map stream network density over a large region and will have lasting implications for modeling and conservation efforts.

Abstract in spanish Los métodos de Sondeo Eléctrico Vertical (VES) y Polarización Inducida (IP) se incorporaron al análisis físico-químico de las muestras de agua de pozo para determinar la extensión vertical de contaminación por petróleo en el subsuelo y las aguas subterráneas desde los almacenamientos de combustible y terminales de distribución en Iganmu, en la zona de Lagos. La interpretación de resultados de VES y IP revelaron cuatro capas geo-eléctricas. Arcilla con resisti (more) vidad y valores IP que van desde 1,5 hasta 14 Qm y 50 - 400 mV / V respectivamente, fue encontrada en la última capa alcanzada por el estudio, excepto en cuatro estaciones de VES, donde se delineó el horizonte de arcilla en la tercera capa. Esto implica que los acuíferos del subsuelo están sellados por una capa impermeable que posiblemente impide que sean contaminados por hidrocarburos y otros materiales desechos de la superficie. Los registros de pozos y la resistividad eléctrica de un sitio de control dentro de la zona fueron incorporados con las mediciones geofísicas y éstas confirman similitud litológica y la presencia de un sellador encima de la capa acuífera. En adición, los resultados de los análisis geo-químicos y físicos llevados a cabo en muestras de agua subterránea de pozos poco profundos dentro del área muestran un nivel insignificante de contaminación por hidrocarburos que no tiene graves consecuencias medioambientales sobre el agua del subsuelo en la zona. Sin embargo, la conductividad eléctrica, la salinidad y los valores TDS obtenidos muestran el alto grado de minerales disueltos (sales) haciendo que el agua sea altamente salina y no apta para beber, ya que está muy por encima de los valores recomendados para ser agua potable. De esta manera se infiere que la laguna de Lagos ha invadido el acuífero en algunos lugares dando paso a la elevada salinidad observada. Abstract in english Vertical electrical sounding (VES) and Induced Polarisation (IP) methods of geophysical survey were incorporated with physiochemical analysis of well water samples to determine vertical extent of petroleum-product contamination in subsurface soils and groundwater from bulk-fuel storage and distribution terminals in Iganmu area of Lagos. Interpreted results of VES and IP revealed four geoelectric layers. Clay with resistivity and IP values ranging from 1.5-14 Qm and 50 - 4 (more) 00mV/V respectively was encountered at the last layer penetrated by the survey except in four VES stations where the clay horizon was delineated at the third layer. This implies that subsurface aquifer is sealed by impervious layer which possibly prevents it from being contaminated by hydrocarbon and other refuse materials from the surface. Borehole log and electrical resistivity survey from a control site within the area were also incorporated with the geophysical measurements and these confirm lithologic similarity and the presence of a sealant above the aquifer layer. In addition to this, the results of the physical and geochemical analyses carried out on groundwater samples from shallow wells within the pack show very negligible level of hydrocarbon contamination which has no serious environmental implications on subsurface water in the area. However, electrical conductivity, salinity and TDS values obtained show high level of dissolved minerals (salts) making the water highly saline and unsuitable for drinking being far above recommended values for drinking water. We thus inferred that Lagos lagoon must have invaded the aquifer in some places leading to high salinity observed.

The performance of stormwater detention tanks with alternative design configurations (insertion in the storm sewer network; volume per impervious hectare) and operating conditions (continuous and intermittent emptying rules) have been evaluated according to an integrated approach. Various performance indices have been adopted to describe the mitigation of the pollution impact to the natural environment, the reduction of the management and maintenance charges for the urban drainage system, the preservation of the normal purification efficiency, and the limitation of the costs at the treatment plant. The US EPA Storm Water Management Model has been used to simulate the rainfall-runoff process and the pollutant dynamics on theoretical catchments and storm sewer networks for an individual event, as well as for a continuous run of events and inter event periods of one year recorded at the rain gauge of Cascina Scala (Pavia, northern Italy). Also the influence of the main characteristics of the urban catchment and the drainage system (area of the catchment and slope of the network) on the performance of alternative design and operating solutions has been examined. Stormwater detention tanks combined with flow regulators demonstrated good performance with respect to environmental pollution: satisfactory performance indicators can be obtained with fairly low flow rates of flow regulators (0.5-1 L/s per hectare of impervious area) and tank volumes of about 35-50 m(3) per impervious hectare. Continuous emptying guaranteed the lowest number and duration of overflows, while an intermittent operation minimised the volume sent for purification reducing the costs and the risks of impairment in the normal treatment efficiency of the plant. Overall, simulation outcomes revealed that the performance indexes are scarcely affected by the area of the catchment and the slope of the drainage network. The result of this study represents a key issue for the implementation of environmental policies in large urban areas. PMID:22387328

This paper examines sections of Wittgenstein's "Philosophical Investigations" with a view to exposing trail-effects of psychology in educational and social practice today. These are seen in understandings of the relations between mind and body, and language and thought, and their influence is identified in such contemporary preoccupations as accounting transparency and the new science of happiness. A Wittgensteinian critique is offered, with attention paid to the idea that "nothing is hidden". Finally a question is raised as to how far it is the imperviousness of these practices to criticism that is the key to understanding them.

Pieces of 304L stainless steel, alumina-coated by plasma spraying, were placed during one week at about 1170K in the furnace of the Waste-to-Energy plant of Limoges, France. The resistance against corrosion was only slightly improved compared to non-coated alloy. The origin of this unsatisfactory result lies in the cracking of the coating that occurred when the pieces were introduced in the furnace, due to the great difference in the Coefficient of Thermal Expansion (CTE) of alumina and 304L steel. However, the plasma-sprayed alumina coatings themselves appear as impervious enough to provide an efficient protection of this alloy against the very corrosive atmosphere of the incinerator.

The impacts of watershed urbanization on streams have been studied worldwide, but are rare in China. We examined relationships among watershed land uses and stream physicochemical and biological attributes, impacts of urbanization on overall stream conditions, and the response pattern of macroinvertebrate assemblage metrics to the percent of impervious area (PIA) of watersheds in the middle section of the Qiantang River, Zhejiang Province, China. Environmental variables and benthic macroinvertebrates of 60 stream sites with varied levels of watershed urban land use were sampled in April, 2010. Spearman correlation analysis showed watershed urbanization levels significantly correlated with increased stream depth, width, and values of conductivity, total nitrogen, ammonia, phosphate, calcium...

The reported investigation had the objective to evaluate the utility of satellite multispectral remote sensing in urban water resources planning. The results are presented of a study which was conducted to determine the economic impact of Landsat data. The use of Landsat data to estimate hydrologic model parameters employed in urban water resources planning is discussed. A decision regarding an employment of the Landsat data has to consider the tradeoff between data accuracy and cost. Bayesian decision theory is used in this connection. It is concluded that computer-aided interpretation of Landsat data is a highly cost-effective method of estimating the percentage of impervious area.

A fuel cell having an electrolyte control volume includes a pair of porous opposed electrodes. A maxtrix is positioned between the pair of electrodes for containing an electrolyte. A first layer of backing paper is positioned adjacent to one of the electrodes. A portion of the paper is substantially previous to the acceptance of the electrolyte so as to absorb electrolyte when there is an excess in the matrix and to desorb electrolyte when there is a shortage in the matrix. A second layer of backing paper is positioned adjacent to the first layer of paper and is substantially impervious to the acceptance of electrolyte.

Continuous extruders have replaced the ram-press as the most common and economical means of producing lead sheathed power cable. The intrinsic ability of the extruder to produce a significantly more uniform sheath composition should allow for a more dilute version of standard alloy compositions to be used, with equal or better performance of the sheath in service. No power cable sheathing alloy has yet been developed expressly for manufacture by a continuous extruder. New techniques for testing of lead pipe provides further insight into the behavior of the alloy sheath near its bursting limit. Simplified impervious splice designs, without the need for lead wiping, have been developed to overcome environmental concerns.

Urbanization is a major driver of land cover change worldwide, yet little is known about how urbanization affects beneficial arthropod communities. This study examined how local and landscape scale variables associated with urbanization influenced parasitic Hymenoptera abundance and diversity in residential and commercial properties along a rural to urban landscape gradient in Wisconsin. At a landscape scale, 300m surrounding sites, land cover percentages were calculated for five cover classes: impervious cover, forest, grassland, agriculture, and urban green space. In addition, habitat diversity (Simpson's index) was calculated for the landscape surrounding study sites. At a local scale (within the boundaries of an individual property), flower diversity, flower area, tree density, and har...

Complex shapes fabricated without machining. Nonaqueous slip-casting technique used to form complexly shaped parts from high-temperature superconductive materials like YBa(2)Cu(3)O(7-delta). Such parts useful in motors, vibration dampers, and bearings. In process, organic solvent used as liquid medium. Ceramic molds made by lost-wax process used instead of plaster-of-paris molds, used in aqueous slip-casting but impervious to organic solvents and cannot drain away liquid medium. Organic-solvent-based castings do not stick to ceramic molds as they do to plaster molds.

Understanding the impacts of climate change on people and the environment requires an understanding of the dynamics of both climate and land use/land cover changes. A range of future climate scenarios is available for the conterminous United States that have been developed based on widely used international greenhouse gas emissions storylines. Climate scenarios derived from these emissions storylines have not been matched with logically consistent land use/cover maps for the United States. This gap is a critical barrier to conducting effective integrated assessments. This study develops novel national scenarios of housing density and impervious surface cover that are logically consistent with emissions storylines. Analysis of these scenarios suggests that combinations of climate and land use/cover can be important in determining environmental conditions regulated under the Clean Air and Clean Water Acts. We found significant differences in patterns of habitat loss and the distribution of potentially impaired watersheds among scenarios, indicating that compact development patterns can reduce habitat loss and the number of impaired watersheds. These scenarios are also associated with lower global greenhouse gas emissions and, consequently, the potential to reduce both the drivers of anthropogenic climate change and the impacts of changing conditions. The residential housing and impervious surface datasets provide a substantial first step toward comprehensive national land use/land cover scenarios, which have broad applicability for integrated assessments as these data and tools are publicly available.

The unitary electrode comprises a porous sheet of fiberglass the strands of which contain a coating of conductive tin oxide. The lower portion of the sheet contains a layer of resin and the upper layer contains lead dioxide forming a positive active electrode on an electrolyte-impervious layer. The strands form a continuous conduction path through both layers. Tin oxide is prevented from reduction by coating the surface of the plate facing the negative electrode with a conductive, impervious layer resistant to reduction such as a thin film of lead or graphite filled resin adhered to the plate with a layer of conductive adhesive. The plate can be formed by casting a molten resin from kettle onto a sheet of glass wool overlying a sheet of lead foil and then applying positive active paste from hopper into the upper layer. The plate can aslo be formed by passing an assembly of a sheet of resin, a sheet of sintered glass and a sheet of lead between the nip of heated rollers and then filling lead oxide into the pores of the upper layer.

Urban streams are degraded due to a variety of physical and chemical factors including impervious surfaces, sewer cross-connections, and multiple chemical contaminants. There is particular interest in the loading of anionic nutrients and heavy metals into urban streams, especially those draining to nutrient sensitive receiving waters. However, there has been less characterization of cation chemistry in urban streams. We examined metal concentrations in archived water samples as part of the stream monitoring program of the Baltimore Ecosystem Study (BES), an urban component of the U.S. National Science Foundation Long Term Ecological Research network. Preliminary analysis suggests sewer cross-connections (storm and sanitary) influence metal concentrations (e.g. Si, Ca, Mg). For example, while silica content is elevated in water draining BES agricultural watersheds, it is also elevated in watersheds with extensive impervious surface coverage, areas with the least water-rock interaction. These results raise questions about the effects of urbanization on chemical weathering, the stoichiometry of urban storm and sewer waters, and the potential for human inputs to function as hydrologic tracers in urban watersheds.

Chloride concentrations are increasing at a rate that threatens the availability of fresh water in the northeastern United States. Increases in roadways and deicer use are now salinizing fresh waters, degrading habitat for aquatic organisms, and impacting large supplies of drinking water for humans throughout the region. We observed chloride concentrations of up to 25% of the concentration of seawater in streams of Maryland, New York, and New Hampshire during winters, and chloride concentrations remaining up to 100 times greater than unimpacted forest streams during summers. Mean annual chloride concentration increased as a function of impervious surface and exceeded tolerance for freshwater life in suburban and urban watersheds. Our analysis shows that if salinity were to continue to increase at its present rate due to changes in impervious surface coverage and current management practices, many surface waters in the northeastern United States would not be potable for human consumption and would become toxic to freshwater life within the next century. ?? 2005 by The National Academy of Sciences of the USA.

The contemporary pattern of urban development in industrialized countries is increasingly taking the form of low density, decentralized residential and commercial development. In the Chesapeake Bay watershed, which is located within the mid-Atlantic region of the United States, dispersed development patterns have been linked to habitat fragmentation and declining water quality. Our objectives were to document how this urbanization process has expanded throughout the watershed and to explore how lands comprising the natural resource base, particularly forests, have been replaced by a matrix of the built environment. We accomplished this by mapping impervious surface cover (houses, roads, etc) across the ~168,000 km2 area using a time series of satellite imagery. We calculated metrics of land use change and used these to estimate the loss of resource lands across the region. We conservatively estimate that 334 km2 of forest, 888 km2 of agriculture and 2 km2 of wetlands have been converted to impervious surfaces between 1990 and 2000. We also used the time series to calibrate a spatial model of urban land use change, and forecasted future development patterns in Maryland out to 2030 under different policy scenarios. Using Maryland Department of Natural Resources' (DNR) Strategic Forest Lands Assessment (SFLA), which evaluates forest resources in terms of their economic and ecologic value, and Maryland's Green Infrastructure, which identifies ecologically valuable patches of contiguous forests and wetlands, we evaluated the vulnerability of natural resources in Maryland. Threats associated with loss and fragmentation were identified.

and Soils. Soil Quality. Biological soil crusts, soil structure and stability, soil cover, permafrost ... exotic aquatic assemblages. Infestations and ... Land birds, forest vegetation structure & composition, fish communities, intertidal communities, salt ...

Keywords: Load - soil interaction, soil structure, soil mechanical properties, FEM (Finite Element Method), Plaxis (Finite Element Code), granular particles, shear stress, DEM (Distinct Element Method), mic...

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.

The cone penetration test (CPT) is used to determine stratification of soil, soil type, soil density and stresses and soil shear strength parameters. This type of information is useful for geotechnical design and information.

The purpose of the ISS OSI Invited Meeting being held in Vienna March 24-27, 2009 is to obtain a better understanding of the phenomenology of underground nuclear explosions for On-Site Inspection (OSI) purposes. In order to focus the technology discussions, we have developed two very general scenarios, or models, of underground nuclear test configurations and phenomena that will help us explore the application of OSI methodologies and techniques. The scenarios describe testing environments, operations, logistics, equipment, and facilities that might be used in conducting an underground nuclear test. One scenario involves emplacement of a nuclear device into a vertical borehole in an area with relatively flat terrain; the other involves emplacement within a tunnel (horizontally) in an area with mountainous terrain. Vertical borehole geometry The example for this scenario is an intermediate yield nuclear explosion carried out in a flat desert area. The ground was cleared and smoothed over a 200 X 200 m fenced area for operational support activities, access to the borehole, and in order to place a few structures to house diagnostics equipment and control functions. Power lines were provided for local electrical power. The vertical emplacement borehole was 2 m in diameter and bored to a depth of 350 m. The emplacement hole was lined with steel pipe in order to keep the hole open and to avoid cave-ins during emplacement of the nuclear device. Emplacement was above the local water table, and the top of the saturation zone is about 30 m below the bottom of the emplacement hole. The detonation point was at a depth of 340 m. All of the rock material removed while drilling the borehole was removed to another place. Diagnostics and control for the test were relatively simple: about 2 dozen high capacity coaxial cables feed from the down hole instruments to the surface and then about 100 m laterally to a diagnostics trailer. Two strong steel cables were used to emplace the device and diagnostic instruments and to support the down hole cables. The borehole was stemmed after the device was emplaced. The stemming material was relatively simple: the hole was backfilled with sand or gravel about 20-30 m above the nuclear experiment package, a grouted plug about 3 m thick is added, and the hole backfilled with a mixture of sand and gravel to the surface. After the test, the testing party removed all structures and power lines and covered the top of the borehole with a small building. Geologic environment before the test--The geology for the test consists of flat-lying alluvium and tuff, with 50 m of poorly consolidated alluvium near the surface and moderately welded tuff from 50 m depth to 50 m below the bottom of the hole. The upper tuff is underlain by a densely welded tuff unit, with basement Paleozoic sedimentary rock beginning at a depth of about 1000 m. The tuff is intact with a few fractures. There are no known faults located within 500 m of the borehole. Alteration of the underground environment--The blast created a spherical or near spherical cavity with a lens of vitrified material at the bottom. There are several zones surrounding the detonation point with decreasing levels of rock damage. The zones are: (1) the crushed zone (several tens of meters)where the rock has lost all prior integrity; (2) the fractured zone (out to a couple of hundred meters) characterized by radial and concentric fissures; and (3) the zone of irreversible strain (out to a couple of thousand meters) with local media deformation. A collapse chimney formed one hour after the detonation, in which overlying material fell into the explosion cavity. This chimney zone reached up to within 50 m of the surface and a small apical void formed (10 m high and 80 m in diameter) at the top of the rubble chimney. The rubble chimney is dry and density is about 20% less than the surrounding intact rock. Alteration at the surface--No surface depression formed, but there is significant 'fluffing' of the surface soil from the effects of the initial shock wave. A few radial and concentric fractures formed from the shock effects within a radius of 200 m of the borehole. Radionuclide environment--No particulates or aerosol radiological material reached the surface. However, the stemming is not completely impervious to gas release and a small amount of gas and vapor was released along the emplacement pipe immediately after the explosion and before the rubble chimney formed. Most of the gas venting stopped as soon as cavity collapse occurred. After the rubble chimney formed and the pressure in the explosion cavity reached equilibrium, gases began to migrate up through the rubble chimney aided by barometric pumping. There is also an unknown fault located 300 m from the explosion cavity that provided another gas migration pathway between the damage zone of the cavity and the surface.

Object-based image analysis (OBIA) has become an established way to detect imperviousness and other land cover classes from very high resolution (VHR) multispectral imagery. Data fusion with LiDAR derived digital surface models (DSM) and large scale vectorial datasets containing building footprints and road boundaries have the potential to significantly improve this method. However, the individual contribution of the large scale vectorial dataset remains unclear. In this paper, we studied the improvement of segmentation and classification results when including a vectorial dataset in the OBIA. Two slightly different segmentation methods making use of the vectorial dataset (boundary suggestion method and absolute boundary method) are compared with each other, with a per-pixel classification...

Tunisia's Jasmine revolution and the Arab Spring are unfolding amidst the resurgence of five sets of debates over the proper role of the international community in democracy promotion efforts abroad, including in the Middle East and North Africa, which were once thought to be impervious to democratic change. These debates, which are explored here within the context of the Arab Spring, range from the normative question of whether the international community should be actively involved in democracy promotion efforts abroad, to what forms of intervention should constitute part of the global arsenal for those intent on seeking democracy's spread. A final section reflects on whether international efforts will contribute to the further strengthening of the Arab Spring or a return to an Arab Wint...

In recent decades, temporal variations in nitrate fluxes and concentrations in temperate rivers have resulted from the interaction of anthropogenic and climatic factors. The effect of climatic drivers remains unclear, while the relative importance of the drivers seems to be highly site dependent. This paper focuses on 2???6 year variations called meso-scale variations, and analyses the climatic drivers of these variations in a study site characterized by high N inputs from intensive animal farming systems and shallow aquifers with impervious bedrock in a temperate climate. Three approaches are developed: 1) an analysis of long-term records of nitrate fluxes and nitrate concentrations in 30 coastal rivers of Western France, which were well-marked by meso-scale cycles in the fluxes and conc...

Ceramic BeO disks used as radiation detectors have been evaluated in environmental radiation fields by observing the TL and TSEE signals given off after heating the disks. Fluxes of low energy photons cause the values for the two apparent exposure rates to diverge; this provides a measure of the quality of the photon radiation field. The mean of the TL and TSEE derived exposure rates is close to the exposure rate as determined by other means. The TL-TSEE dosimeters perform satisfactorily provided moisture is not allowed to condense onto the BeO and wet its surface when the temperature falls below the dew point. Thin impervious plastic packets or aluminium cans, containing silica gel desiccant, provide adequate protection. (auth)

Topics covered include: NASA Applied Sciences Program; USGS Land Remote Sensing: Overview; QuickBird System Status and Product Overview; ORBIMAGE Overview; IKONOS 2004 Calibration and Validation Status; OrbView-3 Spatial Characterization; On-Orbit Modulation Transfer Function (MTF) Measurement of QuickBird; Spatial Resolution Characterization for QuickBird Image Products 2003-2004 Season; Image Quality Evaluation of QuickBird Super Resolution and Revisit of IKONOS: Civil and Commercial Application Project (CCAP); On-Orbit System MTF Measurement; QuickBird Post Launch Geopositional Characterization Update; OrbView-3 Geometric Calibration and Geopositional Accuracy; Geopositional Statistical Methods; QuickBird and OrbView-3 Geopositional Accuracy Assessment; Initial On-Orbit Spatial Resolution Characterization of OrbView-3 Panchromatic Images; Laboratory Measurement of Bidirectional Reflectance of Radiometric Tarps; Stennis Space Center Verification and Validation Capabilities; Joint Agency Commercial Imagery Evaluation (JACIE) Team; Adjacency Effects in High Resolution Imagery; Effect of Pulse Width vs. GSD on MTF Estimation; Camera and Sensor Calibration at the USGS; QuickBird Geometric Verification; Comparison of MODTRAN to Heritage-based Results in Vicarious Calibration at University of Arizona; Using Remotely Sensed Imagery to Determine Impervious Surface in Sioux Falls, South Dakota; Estimating Sub-Pixel Proportions of Sagebrush with a Regression Tree; How Do YOU Use the National Land Cover Dataset?; The National Map Hazards Data Distribution System; Recording a Troubled World; What Does This-Have to Do with This?; When Can a Picture Save a Thousand Homes?; InSAR Studies of Alaska Volcanoes; Earth Observing-1 (EO-1) Data Products; Improving Access to the USGS Aerial Film Collections: High Resolution Scanners; Improving Access to the USGS Aerial Film Collections: Phoenix Digitizing System Product Distribution; System and Product Characterization: Issues Approach; Innovative Approaches to Analysis of Lidar Data for the National Map; Changes in Imperviousness near Military Installations; Geopositional Accuracy Evaluations of QuickBird and OrbView-3: Civil and Commercial Applications Project (CCAP); Geometric Accuracy Assessment: OrbView ORTHO Products; QuickBird Radiometric Calibration Update; OrbView-3 Radiometric Calibration; QuickBird Radiometric Characterization; NASA Radiometric Characterization; Establishing and Verifying the Traceability of Remote-Sensing Measurements to International Standards; QuickBird Applications; Airport Mapping and Perpetual Monitoring Using IKONOS; OrbView-3 Relative Accuracy Results and Impacts on Exploitation and Accuracy Improvement; Using Remotely Sensed Imagery to Determine Impervious Surface in Sioux Falls, South Dakota; Applying High-Resolution Satellite Imagery and Remotely Sensed Data to Local Government Applications: Sioux Falls, South Dakota; Automatic Co-Registration of QuickBird Data for Change Detection Applications; Developing Coastal Surface Roughness Maps Using ASTER and QuickBird Data Sources; Automated, Near-Real Time Cloud and Cloud Shadow Detection in High Resolution VNIR Imagery; Science Applications of High Resolution Imagery at the USGS EROS Data Center; Draft Plan for Characterizing Commercial Data Products in Support of Earth Science Research; Atmospheric Correction Prototype Algorithm for High Spatial Resolution Multispectral Earth Observing Imaging Systems; Determining Regional Arctic Tundra Carbon Exchange: A Bottom-Up Approach; Using IKONOS Imagery to Assess Impervious Surface Area, Riparian Buffers and Stream Health in the Mid-Atlantic Region; Commercial Remote Sensing Space Policy Civil Implementation Update; USGS Commercial Remote Sensing Data Contracts (CRSDC); and Commercial Remote Sensing Space Policy (CRSSP): Civil Near-Term Requirements Collection Update.

The objective of this research was to develop a new type of cheap anion exchange membranes for use in alkaline fuel cells. The polyelectrolyte anion exchange membrane was prepared by grafting quaternary amines (DABCO, TEA) on the epichlorohydrin polymer, consolidated by reticulation. Obtained ionic conductivities are over 10{sup -2} S.cm{sup -1}, with a concentration of positive ionic sites of a few milli-equivalents per gram of material. Measured anionic transport numbers are greater than 0.90. Membranes, which can absorb 30 to 50 % of water, are quasi impervious to gases such as H{sub 2} and O{sub 2} and can operate at temperatures up to 120 deg C. Alkaline fuel cells assembled with both types of membranes showed good performances. Particular attention was devoted to the membrane-electrode interface. (authors)

An improved perforation sealer is described for use in oil wells, gas wells, and similar boreholes. The sealer includes an at least partially spheroidal body of resilient material of sufficient size to lodge in a perforation as fluid enters the perforation. A flexible skirt of fluid-impervious material is attached to and extends outward about the body for a distance sufficient to overspread the wall surface adjacent to the perforation. When such a sealer seats in a non-circular perforation, the escape of fluid through the unplugged portion of the perforation around the sealer body forces the flexible skirt into or over the opening. This seals the irregular opening and thus reduces or prevents further escape of the fluid. When the pressure within the pipe is reduced and the well is placed on production, the sealer is dislodged and carried to the surface with the produced fluid. (6 claims)

Across the DOE complex, large quantities of contaminated debris and irradiated lead bricks have been accumulated for disposal. Under the US Environmental Protection Agency`s Alternative Treatment Standards, the preferred method of disposal of these wastes is macroencapsulation. Chemically bonded phosphate ceramic (CBPC) is a novel binder that was developed at Argonne National Laboratory to stabilize and solidify various low-level mixed wastes. This binder is extremely strong, dense, and impervious to water. In this investigation, CBPC has been used to demonstrate macroencapsulation of various contaminated debris wastes, including cryofractured debris, lead bricks, lead-lined plastic gloves, and mercury-contaminated crushed glass. This paper describes the fabrication of the waste forms, as well as the results of various characterizations performed on the waste forms. The results show that the simple and low-cost CBPC is an excellent material system for the macroencapsulation of debris wastes.

Nanocarbon-derived electron emission devices, specifically nanodiamond lateral field emission (FE) diodes and gated carbon nanotube (CNT) triodes, are new configurations for robust nanoelectronic devices. These novel micro/nanostructures provide an alternative and efficient means of accomplishing electronics that are impervious to temperature and radiation. For example, nitrogen-incorporated nanocrystalline diamond has been lithographically micropatterned to use the material as an electron field emitter. Arrays of laterally arranged 'finger-like' nanodiamond emitters constitute the cathode in a versatile diode configuration with a small interelectrode separation. A low diode turn-on voltage of 7V and a high emission current of 90 microA at an anode voltage of 70V (electric field of approx. 7V microm(-1)) are reported for the nanodiamond lateral device. Also, a FE triode amplifier based on aligned CNTs with a low turn-on voltage and a small gate leakage current has been developed. PMID:18024363

This paper presents the findings of a qualitative study that explored the impact of neo-liberal policy and ideology on educators and directors working in second-chance Private Training Establishments (PTEs) which were created at the height of the neo-liberal reforms in New Zealand. By examining the experiences of 14 educators and directors in four PTEs, this research found that although those working in second-chance PTEs are not impervious to neo-liberal discourse and policy, they do not automatically reflect a rightist agenda. While assessment, funding, outcomes, and monitoring have encouraged tutors and directors to adopt a more behaviourist approach in the classroom and in their jobs, the findings also indicate that adult educators critically examine and constantly negotiate their practice. (Contains 2 figures and 3 notes.)

Gram-negative bacteria are impervious to many drugs and environmental stresses because they possess an outer membrane (OM) containing lipopolysaccharide (LPS). LPS is biosynthesized at the cytoplasmic (inner) membrane and is transported to the OM by an unknown mechanism involving the LPS transport proteins, LptA-G. These proteins have been proposed to form a bridge between the two membranes; however, it is not known how this bridge is assembled to prevent mistargeting of LPS. We use in vivo photo-cross-linking to reveal the specific protein-protein interaction sites that give rise to the Lpt bridge. We also show that the formation of this transenvelope bridge cannot proceed before the correct assembly of the LPS translocon in the OM. This ordered sequence of events may ensure that LPS is never transported to the OM if it cannot be translocated across it to the cell surface. PMID:22668317

For risk associated with storage of CO2 under the Earth’s surface, the impervious cap is one of the most significant factors. Geological structures such as faults can provide conduits for CO2 to escape through the cap. When conductive faults intersect the storage formation and overlying permeable layers, CO2 leaks may exhibit three distinct behaviors: initial upward migration of fluids through the fault, lateral fluid movement through permeable layers, and continued movement of CO2 along the fault above the leakage pathways. To quantify this behavior, especially the attenuation, we develop a quasi-1D model for migration of buoyant fluid from a reservoir along a conductive fault. The fault can intersect multiple shallower formations. The model accounts for flow from the fault into a ...

The performance of stormwater detention tanks with alternative design configurations (insertion in the storm sewer network; volume per impervious hectare) and operating conditions (continuous and intermittent emptying rules) have been evaluated according to an integrated approach. Various performance indices have been adopted to describe the mitigation of the pollution impact to the natural environment, the reduction of the management and maintenance charges for the urban drainage system, the preservation of the normal purification efficiency, and the limitation of the costs at the treatment plant. The US EPA Storm Water Management Model has been used to simulate the rainfall-runoff process and the pollutant dynamics on theoretical catchments and storm sewer networks for an individual even...

A gas-path leakage seal for generally sealing a gas-path leakage-gap between spaced-apart first and second members of a gas turbine (such as combustor casing segments). The seal includes a generally imperforate foil-layer assemblage which is generally impervious to gas and is located in the leakage-gap. The seal also includes a cloth-layer assemblage generally enclosingly contacting the foil-layer assemblage. In one seal, the first edge of the foil-layer assemblage is left exposed, and the foil-layer assemblage resiliently contacts the first member near the first edge to reduce leakage in the "plane" of the cloth-layer assemblage under conditions which include differential thermal growth of the two members. In another seal, such leakage is reduced by having a first weld-bead which permeates the cloth-layer assemblage, is attached to the metal-foil-layer assemblage near the first edge, and unattachedly contacts the first member.

Summary Structural responses in the bark and wood were described following penetration by Armillaria ostoyae in the roots of 20- to 30-year-old Douglas-fir, western hemlock and western redcedar trees. Tissue necrosis presumably caused by fungal exudates was commonly observed at inoculum contact. In Douglas-fir and western hemlock, A.ostoyae interfered with the initiation of active defence mechanisms involving the development of a lignified zone of impervious tissue (IT), necrophylactic periderm (NP) formation and compartmentalization of infected woody tissue. Breaching of IT and NP barriers was frequent, particularly around the clusters of sclereid cells in western hemlock. In western redcedar, the IT zone was inconspicuous. Induced rhytidome formation occurred in western redcedar either s...

Abstract Tuberculosis (TB), caused by Mycobacterium tuberculosis (Mtb), which claims approximately two million people annually, remains a global health concern. The non-replicating or dormancy like state of this pathogen which is impervious to anti-tuberculosis drugs is widely recognized as the culprit for this scenario. The dormancy survival regulator (DosR) regulon, composed of 48 co-regulated genes, is held as essential for Mtb persistence. The DosR regulon is regulated by a two-component regulatory system consisting of two sensor kinases-DosS (Rv3132c) and DosT (Rv2027c), and a response regulator DosR (Rv3133c). The underlying regulatory mechanism of DosR regulon expression is very complex. Many factors are involved, particularly the oxygen tension. The DosR regulon enables the pathoge...

On-road emissions are a major contributor to rising concentrations of atmospheric greenhouse gases. In this study, we applied a downscaling methodology based on commonly available spatial parameters to model on-road CO(2) emissions at the 1 × 1 km scale for the Boston, MA region and tested our approach with surface-level CO(2) observations. Using two previously constructed emissions inventories with differing spatial patterns and underlying data sources, we developed regression models based on impervious surface area and volume-weighted road density that could be scaled to any resolution. We found that the models accurately reflected the inventories at their original scales (R(2) = 0.63 for both models) and exhibited a strong relationship with observed CO(2) mixing ratios when downscaled across the region. Moreover, the improved spatial agreement of the models over the original inventories confirmed that either product represents a viable basis for downscaling in other metropolitan regions, even with limited data. PMID:22776716

Use of fipronil {5-amino-1-[2,6-dichloro-4-(trifluoromethyl)phenyl]-4-trifluoromethyl)sulfinyl]-1H-pyrazole-3-carbonitrile CAS 120068-37-3} topical pet products on dogs and cats introduces low level residues into residences. Distribution and fate studies of fipronil on pets and in residences were performed to evaluate potential determinants of human exposure. Fipronil, desulfinyl fipronil, fipronil sulfone and fipronil sulfide were measured on hair clippings and brushed hair. The derivatives usually represented <10% of fipronil applied. Cotton gloves worn over impervious nitrile gloves, cotton cloths placed indoors in locations frequented by pets, and cotton socks worn by residents as direct dosimeters collected fipronil and its derivatives listed above in low amounts during 4-week study periods. Subsequent acid hydrolysis urine biomonitoring did not reveal significant excretion of biomarkers at ppb levels. The human exposure potential of fipronil is low relative to levels of health concern. PMID:22938575

Potassium sulphate fluid has been used in wells in the Rainbow Field at times when Fort Simpson shale was to be drilled. An evaluation of the process was conducted. The focus of the system evaluation was cost and problem time. Since the introduction to the Rainbow Field in 1996, results have been found to be favourable. The cost savings was estimated at $11,000 to $19,000 per well. Characteristics features of the potassium sulphate system are: (1) it minimizes borehole instability and is impervious to anhydrite contamination, (2) presents minimal environmental risk and disposal issues, and (3) is an effective fluid for hole cleaning provided chemical dispersion is kept to a minimum. The potassium sulphate mud system resulted in 15 to 23 fewer problem hours per well. It was concluded that the use of potassium sulphate fluid compared very favourably with gel chemical-polymer performance. 8 refs., 8 figs.

A subsurface safety valve for use in subterranean oil and gas well which is actuated by pressure fluctuations in the tubing-casing annulus is disclosed. The safety valve assembly consists of a safety valve mounted in a packer which is actuated by a subsurface control located above the packer. Annulus pressure variations are controlled by a surface unit. The subsurface control utilizes a reference pressure chamber in which the pressure is initially adjustable to compensate for hydrostatic pressure in the annulus. Leakage of the gas in a dome pressure chamber in the subsurface control is impeded by the presence of a barrier fluid impervious to the passage of gas there through, with the barrier fluid being maintained at a higher pressure than the reference pressure in the dome charged chamber.

The goal of this paper is to evaluate the DisTrad sharpening technique for deriving land surface temperatures over urban areas. While the original DisTrad technique is based on the correlation between land surface temperature and NDVI, this study evaluates the performance of DisTrad over different land covers by analysing the correlation between land surface temperature and 15 different indices: BASVI, R, B, NDWI, NDBaI, SVI, SAVI, NDBI, NDSI, UI, FC, VC, V, IBI, NDVI. In addition, we have analysed the correlation between land surface temperature and impervious percentage. These indices and land surface temperature were derived from a Landsat 7 ETM+ image of 2001 covering the city of Dublin. It is concluded that for most indices selecting 25% of the pixels with the lowest coefficient of va...

The east flank of the Rock Springs uplift and the adjacent Wamsutter arch contain several large hydrocarbon accumulations. Among these accumulations are Patrick Draw field, which produces oil and gas from a stratigraphic trap in the upper Cretaceous Almond formation, and Table Rock field, a faulted anticlinal trap that produces gas from multiple Tertiary, Mesozoic, and Paleozoic reservoirs. The principal petroleum reservoir in Patrick Draw field is a sandstone at the top of the Almond formation. This sandstone attains a maximum thickness of 35 ft (11 m) and pinches out westward into relatively impervious siltstone and shale that constitute the trapping facies. The objective of this investigation is to determine whether or not the stratigraphic trap at Patrick Draw can be detected on a 12 fold, common depth point seismic profile.

Faecal coliform (FC) levels in surface water and clams (Ruditapes decussatus) and variations in environmental parameters were studied in two bivalve harvesting areas in the Alvor lagoon (southern Portugal). Land use and cover characteristics in adjacent subwatersheds were also analysed to assess their contributions as sources of faecal contamination. High FC levels in clams from the harvesting area in the most urbanized subwatershed (impervious surface coverage approximately 10.5%) were positively associated with rainfall and with the cooler periods of the year. FC levels in clams from the least urbanized subwatershed were generally very low and did not present any detectable seasonal trend. From these results, it was concluded that the periodic deterioration of the microbiological quality of clams derives from the cumulative impact of the reservoir of faecal contamination created in urbanized areas, entering into the lagoon during storm water runoff. PMID:17286181

This paper examined the effects of simulated land cover/land use (LC/LU) change from 2000 to 2030 on nutrient loadings to the Chesapeake Bay. The SPAtially Referenced Regression On Watershed Attributes (SPARROW) model was used with anticipated watershed-wide LC/LU change from a growth forecast model that provides spatially explicit probabilities of conversion to impervious surface. The total nitrogen (TN) and total phosphorus (TP) loadings estimated to enter the Chesapeake Bay were reduced by 20% and 19%, respectively. In general, as development replaced other LC/LUs from 2000 to 2030, TN and TP runoff was significantly reduced by losses of non-point, non-urban source loadings, yields, and land-to-water delivery. The simulation results suggest future changes in landscape composition and co...

This study examines the determinants of urbanized area across a 10,000-mile square swath in central North Carolina, an area undergoing extensive conversion of forest and agricultural land. We model the temporal and spatial dimensions of these landscape changes using a database that links five satellite images spanning 1976-2001 to a suite of socioeconomic, ecological and GIS-created explanatory variables. By specifying the complementary log-log derivation of the proportional hazards model, we employ a methodology for modeling a continuous time process - the conversion of land to impervious surface - using discrete-time satellite data. Spatial hypotheses are tested using several variables derived from the imagery that measure the landscape configuration surrounding a pixel. Empirical result...

A thin film coats impervious urban surfaces that can act as a source or sink of organic pollutants to the greater environment. We review recent developments in the understanding of film and film-associated pollutant behavior and incorporate them into an unsteady-state version of the fugacity based Multimedia Urban Model (MUM), focusing on detailed considerations of surface film dynamics. The model is used to explore the conditions under which these atmospherically-derived films act as a temporary source of chemicals to the air and/or storm water. Assuming film growth of 2.1nmd-1 (Wu et al., 2008a), PCB congeners 28 and 180 reach air-film equilibrium within hours and days, respectively. The model results suggest that the film acts as a temporary sink of chemicals from air during dry and coo...

Quorum sensing (QS) is the regulation of gene expression in response to the concentration of small signal molecules, and its inactivation has been suggested to have great potential to attenuate microbial virulence. It is assumed that unlike antimicrobials, inhibition of QS should cause less Darwinian selection pressure for bacterial resistance. Using the opportunistic pathogen Pseudomonas aeruginosa, we demonstrate here that bacterial resistance arises rapidly to the best-characterized compound that inhibits QS (brominated furanone C-30) due to mutations that increase the efflux of C-30. Critically, the C-30-resistant mutant mexR was more pathogenic to Caenorhabditis elegans in the presence of C-30, and the same mutation arises in bacteria responsible for chronic cystic fibrosis infections. Therefore, bacteria may evolve resistance to many new pharmaceuticals thought impervious to resistance. PMID:21918575

Given the importance of water quality in drinking water sources, the Korean Ministry of Environment is designing and instigating the total maximum daily load (TMDL) program for major large rivers. For the successful implementation of this program, nonpoint pollutants resulting from various land uses should be controlled. Especially, paved areas such as parking lots and bridges are stormwater intensive land uses because of their high imperviousness and high pollutant mass emissions from vehicular activity. Vehicle emissions from these paved areas include various pollutants such as heavy metals, oil, grease and particulates. This research was conducted to investigate the magnitude and nature of the stormwater emissions with the goal of quantifying stormwater pollutant concentrations and mass...

A 34?year time series (1972?2006) of Landsat imagery for a portion of Snohomish and King Counties, Washington (the Snohomish Water Resource Inventory Area (WRIA)) was analyzed to estimate the amount of land that was converted into impervious surface as a result of urban and residential development. Spectral unmixing was used to determine the fractional composition of vegetation, open, and shadow for each pixel. Unsupervised and supervised classification techniques were then used to derive preliminary land cover maps for each time period. Digital orthophotos were used to create agricultural, forest management, high elevation, and riparian masks. In conjunction with established Urban Growth Areas (UGAs), these masks were utilized for the application of spatial rules that identified imperviou...

A walk-through survey was conducted at Permapost Products Company, Hillsboro, Oregon in June, 1979. Area air monitoring for pentachlorophenol was conducted using a NIOSH method and a silica-gel tube technique. The facility treated prefabricated bridge structures, playground equipment, picnic tables, and other specialty items with pentachlorophenol or chromated copper arsenate. The facility had no formal medical-monitoring program. Audiometric testing was performed annually on a contract basis. The company utilized the local hospital emergency room, located 5 minutes away. Work practices, processing methods, and protective equipment such as cartridge half-face respirators, elbow length gloves, and impervious aprons were used to control exposures to the wood preservatives. The authors note that since they took only a small number of samples, a meaningful comparison of the two analytical methods cannot be made.

A boom structure comprises a skirt of impervious fabric, elongated floating means in the form of pipes, and spacers which are attached to the floating means and to the upper and lower edges of the skirt for keeping the skirt extended. The floating means are constituted by two adjacent plastic pipes held together by lashings. The spacers are constituted by short pieces of pipe, also of plastic material, with the axial direction transversely of the longitudinal direction of the boom. The spacers are attached to the floating means of the same lashings, which may be constituted by belts provided with buckles. The supporting structure of the boom consisting of the lashed pipes and pieces of pipe give the boom good sideways stability and also sufficient flexibility in the vertical plane.

The purpose of this study was to investigate the stability of three distinct tutor behaviors (1) use of subject-matter expertise, (2) social congruence and (3) cognitive congruence, in a problem-based learning (PBL) environment. The data comprised the input from 16,047 different students to a survey of 762 tutors administered in three consecutive semesters. Over the three semesters each tutor taught two of the same course and one different course. A generalizability study was conducted to determine whether the tutor behaviors were generalizable across the three measurement occasions. The results indicate that three semesters are sufficient to make generalizations about all three tutor behaviors. In addition the results show that individual differences between tutors account for the greatest differences in levels of expertise, social congruence and cognitive congruence. The study concludes that tutor behaviors are fairly consistent in PBL and somewhat impervious to change. Implications of these findings for tutor training are discussed. (Contains 2 tables.)

An irrigation runoff study on a residential lawn was conducted in California, northeast of Sacramento, during the summer and fall of 2008 to investigate the contribution of turf uses of pyrethroids to residues in Californian urban creek sediments. This study examined how over irrigation (i.e., irrigation that produces runoff) in the summer season may transport recently applied pyrethroids. The study included liquid and granular applications of both bifenthrin [(2-methyl-3-phenyl-phenyl) methyl 3-(2-chloro-3,3,3-trifluoro-prop-1-enyl)-2,2-dimethyl-cyclopropane-1-carboxylate] and beta-cyfluthrin [Cyano(4-fluoro-3-phenoxyphenyl)methyl 3-(2,2-dichloroethenyl)-2,2-dimethyl-cyclopropanecarboxylate]. Generally, runoff did not occur at irrigation rates of 2.03 cm/h (0.8 in/h) but did occur when the irrigation rates were increased to about 3.81 cm/h (1.5 in/h), generating chemical losses in the first runoff event of up to 0.58 and 0.08% of applied for beta-cyfluthrin and bifenthrin, respectively. Chemical runoff losses dropped significantly between over-irrigation events with the third over-irrigation event chemical runoff losses representing 0.026 and 0.015% of applied for beta-cyfluthrin and bifenthrin, respectively. Runoff losses were generally less for liquid formulations than granular formulations but within a factor of three. Additionally, the study included a simulated winter rainstorm 8 wk after application. The low runoff losses from turf seen in this study suggest that other sources could be contributing to observed residues in urban streams. Other sources could include pyrethroids ending up on impervious surfaces, such as concrete driveways from off-target applications to turf, spills, and other poor handling practices, or pyrechroids applied directly to impervious surfaces for insect control. PMID:21520766

The City of Minneapolis, Minnesota has set a goal to have the stormwater utility be revenue-neutral, with higher stormwater fees offset by lower sanitary sewer charges. A credit system was designed to promote the adoption of onsite best management practices, even on residential and other small sites. This paper examined the city council's policy considerations that drove the impervious-surface-based stormwater utility fee ordinance, the legal and institutional barriers that had to be overcome, and the successes and failures of the effort. The policy objective was to have an equitable stormwater fee credit system, whereby property owners paid for stormwater management in proportion to the demand their properties placed on the system. As such, property owners were encouraged to manage stormwater onsite. The first objective was achieved when in March 2005 the City of Minneapolis began charging property owners for management of stormwater based on the degree to which their property was covered by impervious surfaces. Previously, property owners had paid a combined stormwater and sewerage fee based on water usage. The city also launched a program allowing property owners to apply for fee reductions of up to 100 percent when establishing onsite water-quality or water-quantity treatment systems, such as rain gardens, detention ponds and green roofs. The charges for the properties were based on the size of the property and the land use. It was determined that the city's policy could not accommodate all of the economic issues in green roof development. This paper demonstrated that it is not yet clear that the fee and performance-based fee reduction program has been a significant contributor to the growth of green building in the area. 7 refs., 1 tab.

The biological portion of soil can be used to differentiate displaced soils. Fatty acid analyses of soils yield characteristic "fingerprints" that are unique to a given soil at a given time. We found that molecular techniques for fingerprinting the soil successfully identified different soils and ...

The authors tested five composite soil samples from a former refinery. The samples included a reference soil (Mineral Oil and Grease, MO and G < 40 ppm), thermally-treated soil, biotreated soil, and two untreated soils. They evaluated toxicity using the earthworm E. foetida, lettuce, cress, barley, Microtox, green algae, fathead minnow, and D. magna. The endpoints measured were lethality, seed germination, root elongation, growth, and bioluminescence. Toxicity, as measured by the number of positive responses, increased as follows: biotreated soil < untreated soil No. 1 < reference soil < thermally-treated soil and untreated soil No. 2. The biotreated soil generated only one positive response, whereas the thermally-treated soil and untreated soil No. 2 generated five positive responses. The most sensitive and discriminant terrestrial endpoint was lettuce root elongation which responded to untreated soil No. 1, thermally-treated soil, and reference soil. The least sensitive was barley seed germination for which no toxicity was detected. The most sensitive and discriminant aquatic endpoint was green algae growth which responded to untreated soil No. 1, thermally-treated soil, and reference soil. The least sensitive was D. magna for which no toxicity was detected. Overall, soil and aqueous extract toxicity was spotty and no consistent patterns emerged to differentiate the five soils. Biotreatment significantly reduced the effects of the contamination. Aqueous toxicity was measured in the reference soil, probably because of the presence of unknown dissolved compounds in the aqueous extract. Finally, clear differences in sensitivity existed among the test species.

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.

There is a growing need for raster-based soil data to support modelling at regional and continental scales. The GlobalSoilMap consortium aims to satisfy this need with the production of a suite of digital soil maps of various soil properties at six standard depths for most of the land surface of the Earth. Initially, the maps will be produced using legacy soil data (soil data already available). In the United States, the State Soil Geographic (STATSGO2) database is a rich source of legacy soil information, but the STATSGO2 map is vector-based and soil components' soil property data is organised by horizon. We therefore applied the equal-area spline function to the soil components of STATSGO2 map units in order to obtain estimates of soil organic carbon (SOC) content at the GlobalSoilMap st...

Model soil contamination with Cr, Cu, Ni, and Pb in the dry steppes and semideserts of southern Russia has worsened the biological soil properties. With respect to the degree of deterioration of the biological properties, the soils can be arranged in the following sequence: dark chestnut soils > chestnut soils > light chestnut soils > brown semidesert soils > sandy brown semidesert soils. The sequence of metal oxides according to the adverse effect on the biological soil properties is as follows: CrO3 > CuO ? PbO ? NiO.

A soil-slurry washing technique to decontaminate soils containing low-solubility nonionic organic pollutants was investigated, using phenanthrene as a model pollutant. The technique is based on first transferring the sorbed phenanthrene from the soil to anionic surfactant-coated oxide particles, and then separating these anionic surfactant-coated oxide particles with the sorbed phenanthrene from the soil slurry via a magnetic separation technique. The decontamination of two soils with different particle sizes and soil organic matter content was investigated. The proposed soil-slurry washing technique was effective in removing a strongly sorbing nonionic organic contaminant from soil slurries. Various operational scenarios of multistage soil-slurry reactors were evaluated with a mathematical model.

We reviewed the published evidence of lead (Pb) contamination of urban soils, soil Pb risk to children through hand-to-mouth activity, reduction of soil Pb bioavailability due to soil amendments, and methods to assess bioaccessibility which correlate with bioavailability of soil ...

In this study, the soil buffer capacity (soil BC) was measured for 80 topsoil samples of the most dominant soil forms in a small-scale farming area. Soils used in the study ranged from weakly to strongly buffered, with soil BC values ranging from 0.12 to 2.23 cmol (+) kg-1 pH unit-1. Relationships o...

The European Journal of Soil Biology covers all aspects of fundamental and applied soil biology relating to soil microbial and faunal ecology, and processes promoted by soil organisms. Soils from managed and natural ecosystems of biomes worldwide are of interest, and the Journal is open to su...

Soil texture represents the relative proportion of soil particles with different sizes, which is a fundamental physical property of soils, correlated to just any other soil property. Soil hydraulic properties are difficult to determine, especially for large areas of land. Predictive models to estima...

P-spiked Linz-Donawitz (LD) slag was used as a soil additive to improve physico-chemical soil properties and in situ stabilize Cu and other trace metals in a sandy Cu-contaminated soil (630 mg kg-1 soil) from a former wood preservation site. The LD slag was incorporated into the contaminated soil to...

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...

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

Soil aggregation is influenced by the soil environment and is a factor in soil carbon sequestration. Sandy Coastal Plain soils often do not have the clay to promote aggregation nor have been considered soils with high levels of aggregation. This study was conducted to examine the aggregate morpholog...

Soil washing technologies are designed to transfer contaminants from soil to a liquid phase. he BioGenesis Soil Washing Technology uses soil washing with a proprietary surfactant solution to transfer organic contaminants from soils to wastewater. ontaminant levels are further red...

Adaptation of microorganisms to the environment is a central theme in microbial ecology. The objective of this study was to investigate the response of ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea (AOA) to a soil medium shift. We employed two rice field soils collected from Beijing and Hangzhou, China. These soils contained distinct AOB communities dominated by Nitrosomonas in Beijing rice soil and Nitrosospira in Hangzhou rice soil. Three mixtures were generated by mixing equal quantities of Beijing soil and Hangzhou soil (BH), Beijing soil with sterilized Hangzhou soil (BSH), and Hangzhou soil with sterilized Beijing soil (HSB). Pure and mixed soils were permanently flooded, and the surface-layer soil where ammonia oxidation occurred was collected to determine the response of AOB and AOA to the soil medium shift. AOB populations increased during the incubation, and the rates were initially faster in Beijing soil than in Hangzhou soil. Nitrosospira (cluster 3a) and Nitrosomonas (communis cluster) increased with time in correspondence with ammonia oxidation in the Hangzhou and Beijing soils, respectively. The 'BH' mixture exhibited a shift from Nitrosomonas at day 0 to Nitrosospira at days 21 and 60 when ammonia oxidation became most active. In 'HSB' and 'BSH' mixtures, Nitrosospira showed greater stimulation than Nitrosomonas, both with and without N amendment. These results suggest that Nitrosospira spp. were better adapted to soil environment shifts than Nitrosomonas. Analysis of the AOA community revealed that the composition of AOA community was not responsive to the soil environment shifts or to nitrogen amendment. PMID:22145990

This paper explains the genesis, classification and geography of soil mainly in relation to life. In soil science, the basic field of dealing with the component, classification and distribution of soil is called pedology or soil geography. The fist chapter describes the definition of soil and the process of its genesis. The next chapter deals with the characteristics, genetic causes and distribution of typical soil at present in Japan and in the world. The ways of classifying soil are divided roughly into 2 schools and 17 kinds of typical soil types are explained. The heading of the third Chapter is the genesis and development of soil in geohistory and 3 theories are explained. Soil can not be produced without life. Therefore soil does not exist on the planets other than the earth. The last chapter describes the preservation functions towards the earth environment and the countermeasures of maintenance in connection with soil systems. 42 refs., 8 figs., 5 tabs.

...of the biopolymer salt formulation related to soil stabilization and dust control. DATES: Written...of synthetic, petroleum-based polymers for soil amendment applications to achieve increased soil strength, reduced air transport, and...

...for Registration Amendments To Terminate Certain Soil Uses AGENCY: Environmental...EPA's order for the amendments to terminate soil uses, voluntarily...effective date of the amendment of methyl bromide products that include soil uses other...

Different field and laboratory methods for determining the hydraulic properties of unsaturated soils were studied. Drying moisture retention curves were measured on undisturbed soil samples with a pressure plate apparatus, and wetting soil moisture retent...

...facility were excavated into the unsaturated portion of the alluvial aquifer...contaminating the surrounding soil and water drainage pathway...Site in which contaminated soils, sediments, tank, and buildings...and disposal of contaminated soils and sediments, removal...

Investigations were carried through to test the effects of different copper contents in soils on soil fauna. The experiments were carried out in vineyards. Soil copper contents were correlated with the contents in invertebrates as earthworms, spiders, bee...

...wet soils, and soils and sediment associated with mosses, lichens and algal mats. The applicant will extract nematodes, tardigrades and rotifers from these soils for identification and classification. The collection of these samples will help to...

CO2 concentration in soil air also measured: disposable chromatographic tubes ( Buyanovsky .... decomposition of corn, wheat, and soybean residue. Soil Sci. ... Crop residue input to SOM on ... Significance of microbial tissue to soil organic ...

Aug 9, 2009 ... In a logical continuation of our soil characterization studies for mare soils, we .... Ferromagnetic Resonance (FMR) measurements performed in the .... soils in proportions correlated to the type of basalt, the agglutinitic glass ...

...CNDDB 2011a). Mineral-rich clay soils within grassland...and contains the mineral-rich clay soils, subsurface geology...this subunit include thatch build-up from herbaceous plants...substrate components and mineral-rich soils, conditions...

Grace Dearborn's DARAMEND™ Bioremediation Technology was developed to treat soils/sediment contaminated with organic contaminants using solid-phase organic amendments. The amendments increase the soil’s ability to supply biologically available water/nutrients to micro...

Local scientists studied Zn fertilization of flooded rice soils in Bangladesh, India, Indonesia, the Republic of Korea, Egypt, the Philippines, Thailand and Turkey. Diagnosis of Zn deficiency was carried out for submerged rice soils. Soil maps were prepar...

Oct 4, 2012 ... Unfortunately, migration of a soil component (likely iron) into the stakelets ... one of the five soils interfered with Cr determination by X-ray fluorescence; ... A negative correlation was observed between Soil Cu Content and the ...

Soil filters water, decomposes waste, stores heat, and exchanges gases. ... It is a material used for construction, medicine, and art. .... PG County Soil Survey Report; liter-sized plastic bags for each site and marker; newspaper for drying soil on ...

...removing 24 inches of soil, back-filling the excavation with clean soil and reseeding. A thorough...enhancement of wildlife indigenous to the Oquirrh Range...and removal of top soil and other materials...residential dwellings in the community of Pine Canyon,...

This study integrates land-use history, pine ecology, silviculture, soil ecology research and the implications for forest management into one discussion. Best management practices that foster soil recovery include less intensive stand utilization and reduced soil disturbance. Stem-only harvest and longer rotation permit a recovery of soil biodiversity and an accrual of detritus and soil organic matter. Windrowing and similar techniques have dramatic and lasting effects on soil development. No-tillage agriculture as a model for pine plantations is discussed.

in electronic form began in 1970, but the database covers materials in ... AGRICULTURE > ANIMAL COMMODITIES > DAIRY PRODUCTS · Parameter Definition ... AGRICULTURE > SOILS > SOIL MECHANICS · Parameter Definition ...

Both soil nematodes and microorganisms have been shown to be sensitive bioindicators of soil recovery in metal-contaminated habitats; however, the underlying processes are poorly understood. We investigated the relationship among soil microbial community composition, nematode community structure and soil aluminum (Al) content in different vegetated aluminum-rich ecosystems. Our results demonstrated that there were greater soil bacterial, fungal and arbuscular mycorrhizal fungal biomass in Syzygium cumini plantation, greater abundance of soil nematodes in Acacia auriculiformis plantation, and greater abundance of soil predatory and herbivorous nematodes in Schima wallichii plantation. The concentration of water-soluble Al was normally greater in vegetated than non-vegetated soil. The residu...

Abstract The SALTIRSOIL model predicts soil salinity, sodicity and alkalinity in irrigated land using basic information on soil, climate, crop, irrigation management and water quality. It extends the concept of the WATSUIT model to include irrigation and crop management practices, advances in the calculation of evapotranspiration and new algorithms for the water stress coefficient and calculation of electrical conductivity. SALTIRSOIL calculates the soil water balance and soil solution concentration over the year. A second module, SALSOLCHEM, calculates the inorganic ion composition of the soil solution at equilibrium with soil calcite and gypsum at the soil-s CO2 partial pressure. Results from comparing predicted and experimentally determined concentrations, observations and predictions o...

The objective of this project is to design and develop a physico- chemical treatment process for the removal of uranium and heavy metals from contaminated soil to achieve target contamination levels below 35 pCi/g of soil and a target for non-radioactive heavy metals below concentration levels permissible for release of the soil. Ex- situ pilot-scale soil decontamination and leachate treatment test using Chalk River Chemical Pit soil are nearing completion. Soil decontamination tests using Fernald Incinerator Area soil originally scheduled for February 1995 was postponed to May 1995 as result of unexpected delays in the preparation of two drums of soils.

We have conducted a field study of soil gas transport processes using radon gas as a naturally occurring tracer. The experiment monitored soil gas radon activity, soil moisture, and soil temperature at depth; barometric pressure, rainfall, and wind speed were monitored at the soil surface. Linear and multiple regression analysis under natural environmental conditions are influenced by soil moisture content, barometric pressure variations, soil temperature, and soil structure. The effect of wind speed on subsurface radon activities under our field conditions has not been observed. 25 refs., 12 figs., 1 tab.

Understanding the dynamic of soil C is a key to managing soil organic matter to enhance soil fertility and ecosystem functioning and reduce trace gas emission from soils. Our objective was to determine the influence of thermically-dry sewage sludge (TSL) and municipal waste compost and the application management on soil (mixed or on soil surface) applied at sludge (TSL) and municipal waste compost and the application management on soil (mixed or on soil surface) applied at two rates of 30 t ha{sup -}1 and 60 t ha{sup -}1, on CO{sub 2} fluxes, microbial biomass C (MBC) and dehydrogenase activity (DH), during an incubation study. (Author)

Abstract The availability of soil nutrients can have significant influence on water quality and wetland productivity. Nitrogen mineralization is the important process transferred from organic nitrogen to plant-available inorganic forms by soil animals and microorganism. Soil nitrogen mineralization processes in coastal wetlands will be greatly impacted by the significant changes of soil water and salt conditions caused by global climate change in the future. However, further studies concerning the effects of water and salt on soil nitrogen mineralization is still needed. The influences of other soil physical-chemical properties and plant community on soil nitrogen mineralization processes are also concluded. The influencing mechanism of soil nitrogen mineralization can be explained using t...

The geologic conditions in many regions of the United States will not permit the development of economical high-deliverability gas storage in salt caverns. These regions include the entire Eastern Seaboard; several northern states, notably Minnesota and Wisconsin; many of the Rocky Mountain States; and most of the Pacific Northwest. In late 1997, the United States Department of Energy (USDOE) Federal Energy Technology Center engaged Sofregaz US to investigate the commercialization potential of natural gas storage in Lined Rock Caverns (LRC). Sofregaz US teamed with Gaz de France and Sydkraft, who had formed a consortium, called LRC, to perform the study for the USDOE. Underground storage of natural gas is generally achieved in depleted oil and gas fields, aquifers, and solution-mined salt caverns. These storage technologies require specific geologic conditions. Unlined rock caverns have been used for decades to store hydrocarbons - mostly liquids such as crude oil, butane, and propane. The maximum operating pressure in unlined rock caverns is limited, since the host rock is never entirely impervious. The LRC technology allows a significant increase in the maximum operating pressure over the unlined storage cavern concept, since the gas in storage is completely contained with an impervious liner. The LRC technology has been under development in Sweden by Sydkraft since 1987. The development process has included extensive technical studies, laboratory testing, field tests, and most recently includes a storage facility being constructed in southern Sweden (Skallen). The LRC development effort has shown that the concept is technically and economically viable. The Skallen storage facility will have a rock cover of 115 meters (375 feet), a storage volume of 40,000 cubic meters (250,000 petroleum barrels), and a maximum operating pressure of 20 MPa (2,900 psi). There is a potential for commercialization of the LRC technology in the United States. Two regions were studied in some detail - the Northeast and the Southeast. The investment cost for an LRC facility in the Northeast is approximately $182 million and $343 million for a 2.6-billion cubic foot (bcf) working gas facility and a 5.2-bcf working gas storage facility, respectively. The relatively high investment cost is a strong function of the cost of labor in the Northeast. The labor union-related rules and requirements in the Northeast result in much higher underground construction costs than might result in Sweden, for example. The LRC technology gas storage service is compared to other alternative technologies. The LRC technology gas storage service was found to be competitive with other alternative technologies for a variety of market scenarios.

Impervious surface area (ISA) from the National Geophysical Data Center (NGDC) and land surface temperature (LST) and Normalized Difference Vegetation Index (NDVI) from MODIS averaged over three annual cycles (2003-2005) are used in a spatial analysis to assess the urban heat island (UHI) skin temperature amplitude and its relationship to development intensity, size, and ecological setting for more than 3000 urban settlements over the globe. Development intensity zones based on %ISA were defined for each urban area emanating outward from the urban core to the non-urban rural areas nearby and used to stratify sampling for land surface temperatures and NDVI. Sampling was further constrained by biome and elevation to insure objective intercomparisons between zones and between settlements in different biomes. Stratification based in ISA permits the definition of hierarchically ordered zones that are consistent across urban areas in different ecological setting and across scales. We find that ecological context and settlement sizes significantly influence the amplitude of summer daytime UHI (urban-rural temperature difference). An average of 3.8 C UHI is found in cities built in biomes dominated by forests; 1.89 C UHI in cities embedded by grass/shrubs; and only a weak heat island or sometime heat sink in cities in arid and semi-arid biomes. Overall, the amplitude of UHI is significantly negative correlated (R=-0.66) with vegetation activity difference between urban and rural represented by MODIS NDVI. The average UHI is 4.7 C for global settlements larger than 500 km2, compared to 2.5 C for global settlements smaller than 50 km2 and larger than 10 km2. For all global settlements, the average amplitude of the UHI is 2.6 C in summer daytime and only 1.4 C in winter and impervious surface area is one of the primary drivers for increase in temperature with variations in different ecological context and latitudinal zones. More than 60% of the total variances in LST can be explained by ISA for urban settlements in forests at mid-to-high latitudes. The percentage will increase to more than 80% when only USA settlements are examined. Overall, our results indicate a possible way to examine and compare the amplitude as well as the driver of the UHI over global settlements. The relationship between UHI and key factors indicates that the energy consumption required for cooling is likely to increase with urban growth especially during summertime and in larger urban areas.

The Dominguez Channel Watershed (DCW), located in the southern portion of Los Angeles County (Figure A.1), drains about 345 square miles into the Los Angeles Harbor. The cities and jurisdictions in DCW are shown in Figure A.2. The largest of these include the cities of Los Angeles, Carson, and Torrance. This watershed is unique in that 93% of its land area is highly developed (i.e. urbanized). The watershed boundaries are defined by a complex network of storm drains and flood control channels, rather than being defined by natural topography. Table (1) shows a summary of different land uses in the Dominguez Channel Watershed (MEC, 2004). The Dominguez Watershed has the highest impervious area of all watersheds in the Los Angeles region. The more impervious the surface, the more runoff is generated during a storm. Storm water runoff can carry previously accumulated contaminants and transport them into receiving water systems. Point sources such as industrial wastewater and municipal sewage as well as urban runoff from commercial, residential, and industrial areas are all recognized as contributors to water quality degradation at DWC. Section 303(d) of the 1972 Federal Clean Water Act (CWA) requires states to identify and report all waters not meeting water quality standards and to develop action plans to pursue the water quality objectives. These plans specify the maximum amount of a given pollutant that the water body of concern can receive and still meet water quality standards. Such plans are called Total Maximum Daily Loads (TMDLs). TMDLs also specify allocations of pollutant loadings to point and non-point sources taking into account natural background pollutant levels. This demonstrates the importance of utilizing scientific tools, such as flow and transport models, to identify contaminant sources, understand integrated flow paths, and assess the effectiveness of water quality management strategies. Since overland flow is a very important component of the water balance and hydrology of DCW, a parallel, distributed watershed model that treats flow in groundwater and surface water in a dynamically coupled manner will be used to build a flow model of the watershed. This coupled model forms the basis for modeling and understanding the transport of contaminants through the Dominguez Channel Watershed, which can be used in designing and implementing TMDLs to manage the water quality in this basin. In this report, the coupled surface water-groundwater flow model of DCW will be presented. This flow model was calibrated against a storm that occurred in February 21st, 2004. The model and approach are explained further in the following sections.

Inappropriate soil management practices and heavier farm machinery and equipment have led to an increase in soil compaction in the last two decades prompting increased global concern regarding the impact of soil compaction on crop production and soil quality in modern mechanized agriculture. A 3-yr comprehensive study was established to evaluate the dynamic of freeze-thaw cycles on soil compaction in a clay loam soil. Plots of frozen soils were compared with plots where soils were prevented from freezing with electrically heated blankets commonly used on concrete. Results showed that frequent freeze-thaw cycles over the winter alleviated a majority of soil compaction at the 0 - 20 cm depth. Soil penetration resistance in compacted soils was reduced by 73 and 68% over the winter at the 0 - 10 and 10 - 20 cm depths, respectively, due to dynamic effects of freeze-thaw cycles on soil structure and particles configuration. In unfrozen compacted soils, the penetration resistance was also reduced by 50 and 60% over winter at the 0 - 10 and 10 - 20 cm depths, respectively, due to the biology of soil, microbial activity, and disruptive effects of shrink-swell cycles. These results have demonstrated of how repeated freeze-thaw cycles can alleviate soil compaction, alter soil physical quality and create optimal soil conditions required for profitable growth of agricultural crops. The results from this study will save growers considerable time, money and energy currently required to alleviate soil compaction using other methods such as sub-soiling and deep tillage. We believe that Mother Nature provides ways to reverse soil compaction and improve soil structure and aggregation through the dynamic of freeze-thaw cycles that soils in Montana and other parts of the country go through each year. We concluded that the Mother Nature is the most effective and cheapest way to alleviate soil compaction.

For the assessment of contaminated or remediated soils, aside from chemical analyses, ecotoxicological tests are performed which focus on the retention function of soils (determined by tests with aqueous soil extracts) and on the habitat function (determined by tests with soil). Whereas numerous tests exist as standardized guidelines for identifying the effect of chemicals, this is not the case for the assessment of soil quality. A round-robin test was performed to monitor the comparability of the results from ecotoxicological test methods on soils and to facilitate the standardization of corresponding test methods. Four contaminated soils were tested using a total number of fifteen test systems, including ecotoxicological and genotoxicological tests with soil extracts and soil. In the second part of this publication series, the results obtained from the tests with soil microorganisms and soil fauna are presented. (orig.)

Lhasa is a crucial agricultural region of the Tibetan plateau for local grain and vegetable supplies. Therefore, to sustain soil productivity, it is important to understand how agricultural management practices can cause changes in soil properties. Based on the information from the soil survey conducted in the late 1980s, we selected and sampled the following sites in the summer of 2007: 17 sites of the tillage (A) layer soils and 13 sites of soil profiles, including the tillage and subsoil layers from three types of arable land soils in Lhasa (alluvial soil, steppe soil, and meadow soil). At the same time, another 55 composite samples and core samples were taken from the grain-crop land, open vegetable land and greenhouse vegetable land of the alluvial soil. The selected soil properties w...

Influences of one sewage sludge on degradation of hexazinone and formation of its major metabolites were investigated in four forest soils (A, B, C and D), collected in Zhejiang Province, China. In non-amended forest soils, the degradation half-life of hexazinone was 21.4, 30.4, 19.4 and 32.8 days in forest soil A, B, C and D, respectively. Degradation could start in soil A and C without lag period because the two soils had been contaminated by this herbicide for a long time, possibly leading to completion of acclimation period of hexazinone-degrading bacteria. In forest soils amended with sewage sludge, the degradation rate constant increased by 17.3% in soil A, 48.2% in soil B, 8.1% in soil C and 51.6% in soil D, respectively. The higher degradation rates (soil A and C) in non-amended so...

The aim of the study was to determine effects of a wildfire on soil nutrients and soil microbial functional diversity in short-term time scales. Burned and unburned control soil samples were collected 1day, and 2, 4, 8, 10, 12 and 15months after a shrubbery fire in Yumin county of Xinjiang, Northwest China. Nutrients of soil in each sampling time were detected and soil microbial functional diversity was measured by Biolog Eco plates. Results of the study showed that soil nutrients were significantly affected by fire. Soil pH increased immediately after the wildfire and was higher than that of unburned soil during 15months post fire. Soil organic matter and total N significantly decreased immediately after the fire and was even lower than control soil at the 15thmonth post fire. Soil availa...

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 soil biota we compared inoculation with natural field soil sieved through a 1 mm mesh, a soil suspension also sieved through a 1 mm mesh, and a microbial suspension sieved through a 20 @mm mesh. We tested these effects for different populations of the same plant species and for different soil origins. Pla...

Soil heat flux may play an important role in surface energy balance. In this study, we examined the performances of two methods for predicting soil heat flux from single layer time series data of soil temperature. The first one is the traditional method, which an analytical solution of soil heat flux can be obtained by assuming the surface soil temperature varies sinusoidally. The second one is the connection between surface soil temperature and soil heat flux derived by half-order time derivative/integral, and is based on a simple model of heat transfer described by a one-dimensional diffusion equation with a constant heat diffusivity. Good agreements between measured and predicted soil heat fluxes were found for both methods. However, it was shown that the half-order derivative method has a better capability to capture flux accuracy and trend than the traditional method for long-term soil heat flux estimation. Keywords: soil heat flux, half-order derivative method, soil temperature

A pilot-scale soil washing process, patented by BioTrol, was demonstrated on soil that was contaminated by wood treating waste. The BioTrol Soil Washing was demonstrated in a treatment train sequence with two other pilot-scale units of BioTrol technologies for treatment of waste streams from the soil washer. The three technologies of the treatment train were: The BioTrol Soil Washer (BSW), the BioTrol Aqueous Treatment System (BATS), and the Slurry Bioreactor (SBR). The BioTrol processes were evaluated on pentachlorophenol (PCP) and polynuclear aromatic hydrocarbons (PAHs), which were the primary soil contaminants at the site. The sandy site soil, consisting of less than 10% of fines, was well suited for treatment by soil washing. The BSW successfully separated the feed soil (100% by weight) into 83% of washed soil, 10% of woody residues, and 7% of fines. The soil washer achieved up to 89% removal of PCP and PAHs, based on the difference between their levels in the feed soil and in the washed soil. The BATS degraded up to 94% of PCP in the process water from soil washing. The SBR achieved over 90% removals of PCP and 70-90% removals of PAHs, respectively from the soil washing. Cost of a commercial-scale soil washing, assuming use of all three technologies, was estimated to be $168 per ton of treated soil.

Persistence and degradation of deethylatrazine, the primary metabolite of atrazine, was measured in soil with atrazine history (15 consecutive years of atrazine application) and no atrazine history (no atrazine application for 15 consecutive years). Uniformly ring-labeled {sup 14}C-deethylatrazine was applied to surface and subsurface soils for metabolism studies. After 60 d of incubation, mineralization of deethylatrazine to {sup 14}CO{sub 2} in the atrazine-history surface soil was twice that in the no-history surface soils (34% and 17% of the applied {sup 14}C, respectively). In surface soils, 25% of the applied {sup 14}C remained as deethylatrazine in the atrazine-history soil, compared with 35% in the no-history soil. Microbial plate counts indicated an increase in numbers of bacteria and fungi in soils incubated with deethylatrazine compared to control soils. Total microbial biomass of soils incubated with deethylatrazine, as determined by CO{sub 2} efflux using an infrared (IR) gas analyzer, showed no significant difference between atrazine-history, and no-history soil, but did show an increase above untreated control soils. Prior to treating soils with deethylatrazine, specific deethylatrazine degraders were quantified using a {sup 14}C-most-probable-number procedure. Deethylatrazine degraders were more numerous in atrazine-history surface soil compared to no-history surface soil. After incubation of soils with deethylatrazine, deethylatrazine degraders were more numerous in both history soils as compared to control soils. From these studies, it appears that deethylatrazine is degraded microbially to a greater extent in soils that have had long-term exposure to atrazine at field application rates compared to soils with no long-term exposure. Decreased persistence of this major metabolite of atrazine in atrazine-history soils is important in that there will be less available for movement in surface runoff and to groundwater.

Rill erosion is an accelerated form of soil degradation. It removes much more soil and nutrients from the agricultural land than sheet erosion. Soils in the southern sub-watershed of Lake Balaton are especially prone to rill erosion and they contribute to siltation of ditches, to muddy floods and to eutrofication of the lake. The parent material in this region is mainly (sandy) loess and the soils are already moderately or strongly eroded thus, the low tolerance of loess against erosion determines erodibility. Identification of soils with high risk of rill erosion is crucial to plan mitigation measures. Soil erodibility has been investigated in this study in the catchment of Tetves stream. The USLE soil erodibility factor and soil slaking are widely accepted indicators for soil erosion. Both of them are published for all soil texture classes in handbooks of soil mapping. We have found that erodibility derived from our physical model has a close linear correlation with the product of the USLE soil erodibility factor and soil slaking grade thus, USLE could be directly used to assess parameters for physical based models. Rill erosion is highly probable if the product of KUSLE X slaking grade is above 2. Digital maps were produced to delineate soils with high potential for rill erosion. The basic data for the soil properties were drawn from the 1:10,000 soil map. Soil texture classes were used to assign KUSLE and slaking grade to the soil units. Beyond soil properties, other factors also influence rill formation: slope, surface cover, rainfall intensity. However, identifying soil properties, which make soils prone to rill erosion, is an important initial step for the reduction of diffuse agricultural loads to Lake Balaton. It might be the objective of River Basin Management Plans in the Water Framework Directive to prevent rill erosion and our study provides scientific evidence for targeting this policy.

One goal of soil carbon (C) sequestration, a greenhouse gas mitigation strategy, is to increase the mass of C stored in agricultural soils. Reducing soil disturbance, e.g. no-tillage, facilitates soil fungal growth and results in higher C sequestration rates. However, the specific mechanisms associa...

Soil microbial communities are influenced by many factors, including root presence, soil disturbance, variation in soil type and texture, and gradients in resource availability. We investigated the relationship between these factors and the associated soil microbial communities under Pinot Noir grap...

Under semiarid conditions, soil quality and productivity can be improved by enhancing soil organic matter content by means of alternative management practices. In this study, we evaluated the feasibility of no-till (NT) and cropping intensification as alternative soil practices to increase soil orga...

Alternative soil fumigants to methyl bromide do not distribute as readily in the soil. Application methods and soil conditions are important to their efficacy. Metam sodium degrades in the soil to a fumigant, methyl isothiocyanate (MITC). It is soluble and can be applied with irrigation water. E...

Organic farming systems utilize organic amendments, diverse crop rotations and cover crops to promote soil fertility and enhance soil health. These practices increase biologically available forms of soil organic matter, and increase the activities of beneficial soil microbes and invertebrates. Physi...

Children ingest soil, either accidentally via hand-to-mouth behavior or deliberately. In this manner, a child ingests on average between 50 and 200 mg soil/day, although amounts of as much as 60 g/day have also been observed. Hence, soil ingestion can be a main route of exposure to soil-borne ...

The safe cultivation of genetically modified plants (GMP) requires a comprehensive investigation of possible harmful soil changes - especially with respect to the natural habitat function of soils for soil organisms, as mentioned in §2 of the BBodSchG (Bundesbodenschutzgesetz; German Federal Soil Pr...

Surfactants may affect soil structure differently depending upon a soil’s wettability or the quality of rainfall or irrigation water. This study evaluated surfactant and water quality effects on water repellency and water-stable aggregation of wettable and nonwettable soils by quantifying water dro...

Soil pore volume as well as pore size, shape, type (i.e. biopore versus crack), continuity, and distribution in soil affect soil water and gas exchange. Vertical and lateral drainage of water by gravitational forces occurs through large, non-capillary soil pores, but redistribution and upward moveme...

Soil organic matter (SOM) in allophanic soils is supposed to accumulate due to protection caused by binding to allophane, aluminium and iron. We investigated a catena of allophanic and non-allophanic soils in Costa Rica to determine the effect of such binding mechanisms on SOM chemistry. These soils...

Soil management can be improved if soil spatial variability is taken into account. We initiated a study to quantify spatial variability of soil hydraulic properties. Initially we focused on hydraulic conductivity of saturated soil (Ks) by horizons. In situ Ks measurements made in the Ap, Bt, and t...

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.

Displacement of soil particles caused by erosion influences soil condition and fertility. To date, the cesium 137 isotope (137Cs) technique is most commonly used for soil particle tracing. However when large areas are considered, the expensive soil sampling and analysis present an obstacle. Infrared...

The assessment of greenhouse gas emissions from soils requires an accurate knowledge on the fate of carbon (C) and nitrogen (N) in soils. This knowledge shouldn't be limited to C and N stocks in soils but should incorporate the quantification of functional soil organic matter (SOM) fractions with di...