The effort of vegetation restoration in recent decades has been effective for soil erosion control, but accompanied by a drastic reduction of water yield in the main tributaries of the Yellow River. This has led to an emerging debate notably about forest development. Increased temperature and decreased precipitation may also have contributed to water yield reduction. An essential key for developing an integrated land-use and water management approach is to understand and separate the hydrological response to changes in land use and climate. In this study on multiple scales ranging from single tree to watershed, water balance components, vegetation structure dynamics, and soil hydraulic properties will be investigated and continuously monitored on selected plots with vegetation typical to the region. Our research will be carried out in the semihumid/-arid transition region of Jinghe which is an important tributary of the Yellow River. We follow a nested approach on scales of plots and watersheds along a upstream/downstream situation in a representative subbasin. On the basis of our measurements, the process-oriented model BROOK90 will be implemented for predicting the water yield response to changes in climate and vegetation depending on relief and soil conditions. The results obtained from plot studies will be used to parameterize the distributed model SWIM. In a next step, SWIM will be fitted to the catchment discharge and to assess the effect of different land use and vegetation management on water yield. This assessment will provide a solid foundation for how much of the catchment area can be changed by vegetation restoration through forest management to maintain a certain level of water supply security that will ensure a more sustainable regional development.
The project was granted to Dr. Kai Schwärzel (as PI) and to the TU Dresden (as liable institution) in 2011 when Dr. Schwärzel was working as senior researcher at TUD. As a result of the career move of Dr. Schwärzel from TUD to UNU-FLORES, the project is now under the control of UNU-FLORES.