A catchment is a basic unit of landscape particularly for investigations of hydrologic processes. Typically, the topographic boundary of a catchment coincides with the hydrologic boundary causing any precipitation falling on to the catchment to be routed to a stream where it is transported out of the catchment. Fundamental components of the hydrologic cycle, such as precipitation, runoff and ev...

Abstract This study presents the preliminary stage of development a conjunctive surface-subsurface model for simulating flow in swale. The surface is modelled by one-dimensional dynamic wave equation. To improve accuracy, third-order numerical scheme used to solve advection terms model. Meanwhile, subsurface as vertical through nondeformable porous media without air compression effect. At stage...

This study was conducted to determine if the Agricultural Policy/Environmental Extender (APEX) model could reasonably replicate the effects of silvicultural practices on streamflow and loading of sediments and nutrients. APEX was modified to enhance factors associated with forestry conditions such as rainfall interception by canopy, litter, subsurface flow, nutrient movement, and routing enrich...

61 S in the Gulf of Mexico have documented a large area with seasonally depleted O2 levels (<2 mg L−1). Most aquatic species cannot survive at such low O2 levels. A reduction in NO3–N loading by 30% was initially recommended to reduce hypoxia in the Gulf of Mexico (Mitsch et al., 1999). Following a scientifi c reassessment that recommended a reduction of 45% (USEPA, 2007), the USEPA developed a...

IInfiltration rate and hydraulic conductivity are immensely important parameters for evaluating the hydrology of subsurface environments. Specifically, in disposal wells schemes and in artificial recharge plans both properties must be correctly assessed to better analyze the performance of these installations. In a new research, tanker water and rainfall runoff were injected into a 22.5 m deep ...

Physically based distributed hydrological models aim at an adequate representation of processes, including runoff generation. A significant proportion is generated through the subsurface, i.e. by groundwater flow or unsaturated subsurface stormflow. However, in case high rainfall intensity and/or low soil-surface infiltrability, surface may strongly contribute to total runoff, too, either satur...