unsaturated hydraulic conductivity, K, expressed as a function of the soil water content, u, or the soil water Hysteresis has been found in both the hydraulic conductivity, K, pressure head, c, and the relation between u and c must vs. pressure head, c, relationship, and the soil water content, u, vs. c relationship. This limits the application of a unified solution for be specified before anal...

[1] Since the early 1980s, water management of rice paddies in China has changed substantially, with midseason drainage gradually replacing continuous flooding. This has provided an opportunity to estimate how a management alternative impacts greenhouse gas emissions at a large regional scale. We integrated a process-based model, DNDC, with a GIS database of paddy area, soil properties, and man...

Deep drainage (DD) is recognised as one of the main drivers for dryland and irrigated salinity. Review of the literature on risk and hazard highlights few Australian studies on assessing DD risk and the need to develop new methods for determining DD risk. This study developed a method to map DD risk for the Northern Murray Darling Basin Catchment of the Border Rivers. Deep drainage was predicte...

We evaluated the impacts of natural wetlands and various land uses on stream nitrogen concentration in two grassland-dominated catchments in eastern Hokkaido, Japan. Analyzing land use types in drainage basins, measuring denitrification potential of its soil, and water sampling in all seasons of 2003 were performed. Results showed a highly significant positive correlation between the concentrat...

there is a need to analyze and map rainfall erosivity to assess soil erosion at the regional scale. the objectives of this study were to develop a regional model to estimate seasonal erosivity from seasonal rainfall data and to study temporal and spatial distribution of rainfall erosivity for the gorganrood drainage basin in the northeast of iran. six gauging stations with a high temporal reso...

The lowering of the water table resulting from peatland drainage may dramatically alter C and N cycling in peatland ecosystems, which contain one-third of the total terrestrial C. In this study, tree annual ring width and C (delta(13)C) and N (delta(15)N) isotope ratios in soil and plant tissues (tree foliage, growth rings, and understory foliage) in a black spruce-tamarack (Picea mariana-Larix...

Approximately 50,000 ha of native wet Metrosideros forest on the island of Hawai'i experienced a drastic reduction (dieback) of the tree canopy between 1954 and 1977. Two general hypotheses have previously been suggested to explain this phenomenon: 1) Metrosideros dieback has resulted from recently introduced pathogens, and 2) the dieback has naturally occurred previously in Hawai'i, and is rel...

The Coimbatore varieties Co. 213. 214. '281 are compared with Uba in a soil of poor agricultural qualities. The surface soil is a shallow loam with a very stiff clay subsoil. The field is on a low lying flat and drainage is difficult; the crop is also liable to suffer severely in drought. Further details and a partial chemical analysis of the soil are given in the report on the plant cane results.