Abstract. The application of large manure on the agricultural lands that derived from Concentrated Animal Feeding Operations (CAFOs) could cause excess nutrients such as nitrogen and phosphorus transport to groundwater through vadose (unsaturated) zone. objective this study is follows: (1) compare in zone at different Land Management Units (LMUs) for three consecutive years (2004-06) using HYDR...

[1] Disconnected stream-aquifer systems are becoming increasingly common because of lowering groundwater tables. This work focuses on the pathways and rates of infiltration and seepage as streams transition from fully connected to disconnected conditions. HYDRUS-2D simulations show for a connected stream, water infiltrates vertically then moves laterally below the top of the preflooding capilla...

ABSTRACT- Despite the benefits of herbicides, their persistence in soil can harm other plants in next rotations and contaminate ground water. The main purpose of this research is to simulate 2,4-dichlorophenoxyaceticacid(2,4-D) movement in silty clay loam soil using HYDRUS-1D model in a corn root zone. The maximum contaminant level goal, MCLG, of 2,4-D in water resources is 10 ppb. The 3.5 kg a...

infiltration is a complex process that changed by initial moisture and water head on the soil surface. the main objective of this study was to estimate the coefficients of infiltration equations, kostiakov-lewis, philip and horton, and evaluate the sensitivity of these equations and their coefficients under various initial conditions (initial moisture soil) and boundary (water head on soil surf...