Changes in land use might affect the combined C, N and P stoichiometry in soil. The Grain-to-Green Program (GTGP), which converts low-yield croplands or abandoned lands into forest, shrub, and/or grassland, was the largest land reforestation project in China. This study collected the reported C, N and P contents of soil in GTGP zones to achieve the factors driving the changes in the C:N, C:P, a...

ii Notice The information in this document has been funded by the U.S. Environmental Protection Agency under Contract No. 68-C0-0048 and the Superfund Innovative Technology Evaluation (SITE) Program. It has been subjected to the Agency's peer and administrative review, and it has been approved for publication as an EPA document. Mention of trade names or commercial products does not constitute ...

A commercial pharmaceutical analysis chiral method development kit (Chirex Column Kit A, Phenomenex) was used to analyze six pesticide stereoisomer mixtures. The pesticides were selected from the 1994-1995 National Water Quality Assessment Program (NAWQA) covering New Mexico and Texas. Three stereoisomer mixtures were separable on three different columns. The instrumental detection limit and de...

Failures of road embankments on discontinuous permafrost commonly occur during thawing of the foundation soil. As an approximation, weak zones created by thawing of discontinuous permafrost can be considered as ‘voids’ within the foundation. Geosynthetic reinforcements have been used to bridge these ‘voids’ and provide support to the embankment fill. This paper presents results of a numerical i...

We investigated the power of near infrared (NIR) analysis for the quantitative assessment of soil quality in a wildfire chronosequence. The effect of wildfire disturbance and soil engineering activity of earthworms on soil organic matter quality was first assessed with principal component analysis of NIR spectra. Three soil quality indices were further calculated using an adaptation of the meth...

the problem of a footing on slope is encountered regularly in engineering practice, with some noteworthy examples being bridge abutments and basement excavations. in this paper, the bearing capacity of a footing replaced near a slope crest was studied. model tests were carried out using square model footing of 100 mm width. a tank 0.3 m deep, 0.6 m wide, and 0.9 m long was used for the model be...

Studies of craters produced by explosions above and underneath the ground surface are rarely found in the open technical literature. Most reports are confidential and access is limited to government agencies. Much of the information on explosively formed craters found in the literature is based on experimental data. Numerical studies were very limited until recently. An ablity to predict the an...

In order to reduce soil erosion and desertification, the Sloping Land Conversion Program has been conducted in China for more than 15 years, and large areas of farmland have been converted to forest and grassland. However, this large-scale vegetation-restoration project has faced some key problems (e.g. soil drying) that have limited the successful development of the current ecological-recovery...

This research investigates the interannual variability of soil moisture as related to large-scale climate variability and also evaluates the spatial and temporal variability of modeled deep layer (40–140 cm) soil moisture in the Upper Colorado River Basin (UCRB). A three layers hydrological model VIC-3L (Variable Infiltration Capacity Model – 3 layers) was used to generate soil moisture in the ...

The arable land quality assessment system is developed with Visual C++ coupled with ArcGIS engine. The system can provide basic functions of geographic information system, for example, map browsing, overlay analysis, and spatial interpolation. The program has both single-factor evaluation module and comprehensive evaluation module, which evaluate the land quality by field sampling data and othe...