Using long-term data on rainfall and annual runoff, an investigation was made of the spatial and temporal variability of rainfall and runoff in the Casamance River basin located in southern Senegal, West Africa. A 5-year moving average was employed to identify trends in the data. Monthly and annual rainfall tends to have been decreasing, and the annual maximum temperature rising from around the...

The "Grain for Green Project" is a country-wide ecological program to converse marginal cropland to forest, which has been implemented in China since 2002. To quantify influence of this significant vegetation change, Guansihe Hydrological (GSH) Model, a validated physically-based distributed hydrological model, was applied to simulate runoff responses to land use change in the Guansihe watershe...

Rapidly developing coastal regions face consequences of land use and climate change including flooding and increased sediment, nutrient, and chemical runoff, but these forces may also enhance pathogen runoff, which threatens human, animal, and ecosystem health. Using the zoonotic parasite Toxoplasma gondii in California, USA as a model for coastal pathogen pollution, we examine the spatial dist...

Water Erosion Prediction Project (WEPP), a process based erosion model that computes spatial and temporal distributions of surface runoff, soil loss and sediment deposition from overland flow on hillslopes and soil loss and sediment deposition from concentrated flow in small channels. In the present study, surface runoff and soil loss were simulated in a mini watershed (57 ha) of Sitlarao water...

In this study, an Artificial Viscosity (AV) technique was developed for direct runoff calculation, instead of using the conventional Synthetic Unit Hydrograph (SUH) methods. We solved Shallow Water Equations (SWE) with second-order accurate Godunov finite volume model and fourth-order Runge-Kutta explicit scheme. The AV devised a Laplacian biharmonic operator, employed to solve convective terms...

The Chesapeake Bay, the largest estuary in the United States, is rich in natural resources. Its watershed has been impacted by excessive and degraded stormwater runoff from rapid urbanization. We used an empirical approach to investigate how local planning capacity in the Chesapeake Bay watershed affected stream flow. A multiple regression analysis was employed to examine to what extent that th...

[1] The overall water balance and the sensitivity of watershed runoff to changes in climate are investigated using national databases of climate and streamflow for 1,337 watersheds in the U.S. We document that 1% changes in precipitation result in 1.5–2.5% changes in watershed runoff, depending upon the degree of buffering by storage processes and other factors. Unlike previous research, our ap...

Beef cattle feedlots contain unconsolidated surface materials (loose manure pack) that accumulate during a feeding cycle. The effects of varying amounts of unconsolidated surface materials on runoff nutrient losses are not well understood. The objectives of this study were to (1) compare runoff nutrient losses from feedlot surfaces containing varying amounts of unconsolidated surface materials,...

In the Northeast US, saturation excess is the most dominant runoff process and locations of runoff source areas, typically called variable source areas (VSAs), are determined by the available soil water storage and the landscape topographic position. To predict runoff generated from VSAs some water quality models use the Soil Conservation Service Curve Number equation (SCS-CN), which assumes a ...

Use of small plots and rainfall simulators to extrapolate trends in runoff water quality requires careful consideration of hydrologic process represented under such conditions. A modified version of the National Phosphorus Runoff Project (NPRP) protocol was used to assess the hydrology of paired 1 x 2 m plots established on two soils with contrasting hydrologic properties (somewhat poorly drain...