Three different approaches using geographical information systems (GIs) and digital elevation models (DEMs) are described and evaluated for applying the Water Erosion Prediction Project (WEPP) model to assess water erosion in small watersheds. The first approach describes a typical application of the watershed version of WEPP using GIs only as an aidfor construction of required input files. The...

introduction: field plots are widely used in studies related to the measurements of soil loss and modeling of erosion processes. research efforts are needed to investigate factors affecting the data quality of plots. spatial scale or size of plots is one of these factors which directly affects measuring runoff and soil loss by means of field plots. the effect of plot size on measured runoff or ...

Investigations were conducted on both the annual patterns of earthworm casting activity and Ž . the annual variations in soil and phosphorus P transfers by water runoff, under a temperate maize crop, to determine whether there is any time synchronism over the year between these processes that could increase risk of soil erosion. Cast dynamics were measured at 15-day intervals for 1 year. Phosph...

Scale effects exist in the whole process of rainfall―runoff―soil erosion―sediment transport in river basins. The differences of hydrographs and sediment graphs in different positions in a river basin are treated as basic scale effects, which are more complex in the gullied Loess Plateau, a region notorious for high intensity soil erosion and hyper-concentrated sediment-laden flow. The up-scalin...

Responses of a runoff system with slope-length distribution have been studied in detail by many researchers. In those studies, rainfall input to the runoff system was considered a deterministic variable. However, rainfall input should be treated as a random process. In this paper, the Kinematic Wave model is used as a runoff system, and differential equationswhose solutions provide the firstto ...

38 In unburned forests, organic plant litter and live vegetation help stabilize the soil and promote water infiltration. Much of this plant material is consumed during severe wildfires, leaving the bare ground susceptible to elevated postfire water runoff and soil erosion (Shakesby and Doerr 2006). Severe wildfires can also produce a water-repellant layer in the soil that further decreases wate...

The Water Erosion Prediction Project (WEPP) model and the Agricultural Non-Point-Source Pollution Model (AGNPS) were used in conjunction with a geographic information system (GIS) database to predict runoff and sediment discharges for Rock Creek watershed, an agricultural watershed in Ohio, USA. Observed and predicted values were compared for selected storm events in 1988 and 1990. The statisti...

[1] Branching valley networks near the landing site of the Huygens probe on Titan imply that fluid has eroded the surface. The fluid was most likely methane, which forms several percent of Titan’s atmosphere and can exist as a liquid at the surface. The morphology of the valley networks and the nature of Titan’s surface environment are inconsistent with a primary valley formation process involv...