Using WaTEM/SEDEM to Model the Effects of Crop Rotation and Changes in Land Use on Sediment Transport in the Vrchlice Watershed

The Czech landscape has undergone various changes over the last 100 years and been mainly adapted agriculturally for economic purposes. This resulted, among other things, in reservoirs being clogged with sediment. Vrchlice Reservoir was built 1970 to supply drinking water around 50,000 inhabitants, increased sedimentation detected reservoir recent years. Water erosion sediment transport were modeled WaTEM/SEDEM. Sediment volumes measured eight ponds across watershed calibration Modeled results from watersheds covered mostly arable lands generally corresponded values. Although forested watersheds, greatly exceeded yields, indicating high uncertainty using USLE-based models non-agricultural watersheds. scenarios represented pre-Communist, Communist, post-Communist eras. For these periods WaTEM/SEDEM used evaluate three isolated effects: effects of crops on lands, farmland fragmentation, finally land use. change proved be an important factor causing siltation rate (potential 23% reduction yield historical periods), fragmentation played second role 15% can reached by fragmentation). Across all scenarios, lowest rates obtained pre-Communist Communist crop share under current use conditions, implemented, as it re-constructed era. supports idea that introduction green areas within are beneficial help reduce soil siltation.