runoff simulation is a vital issue in water resource planning and management. various models with different levels of accuracy and precision are developed for this purpose considering various prediction time scales. in this paper, two models of ihacres (identification of unit hydrographs and component flows from rainfall, evaporation and streamflow data) and ann (artificial neural network) mode...

Effects of climatic changes, progressing urbanization and improved environmental controls on the simulated urban stormwater quality in a Northern Sweden community were studied. Future scenarios accounting for those changes were developed and their effects simulated with the Storm Water Management Model (SWMM). It was observed that the simulated stormwater quality was highly sensitive to the sce...

Pesticide runoff research relies heavily on rainfall simulation experiments. Most are conducted at a constant intensity, i.e., at a fixed rainfall rate; however, large differences in natural rainfall intensity is common. To assess implications we quantified runoff of two herbicides, fluometuron and pendimethalin, and applied preemergence after planting cotton on Tifton loamy sand. Rainfall at c...

Phosphorus losses in runoff from cropland can contribute to nonpoint-source pollution of surface waters. Management practices in corn (Zea mays L.) production systems may influence P losses. Field experiments with treatments including differing soil test P levels, tillage and manure application combinations, and manure and biosolids application histories were used to assess these management pra...

Recent efforts to reduce phosphorus (P) content of corn grain fed to poultry have led to the development of low-phytic-acid corn. Research is needed to evaluate the environmental impact of the application to cropland of manure from animals fed low-phytic-acid corn. The purpose of this research was to determine P losses in runoff from a bare Piedmont soil (cecil clay loam; clayey, kaolinitic, th...

Manure and animal waste deposited on cropland and grazing lands serve as a source of microorganisms, some of which may be pathogenic. These microorganisms are released along with particles of dissolved manure during rainfall events. Relatively little if anything is known about the amounts and sizes of manure particles released during rainfall, that subsequently may serve as carriers, abode, and...

The role of leaf litter in hydrological processes and soil erosion of forest ecosystems is poorly understood. A field experiment was conducted under simulated rainfall in runoff plots with a slope of 10%. Two common types of litter in North China (from Quercus variabilis, representing broadleaf litter, and Pinus tabulaeformis, representing needle leaf litter), four amounts of litter, and five r...

The placement of stiff-stemmed grass hedges on the contour along a hill slope has been shown to decrease runoff nutrient transport. This study was conducted to measure the effectiveness of a narrow grass hedge in reducing runoff nutrient transport from plots with a range of soil nutrient values. Composted beef cattle manure was applied at dry weights of 0, 68, 105, 142, and 178 Mg ha-1 to a sil...