东江流域丘陵区覆被变化的水文响应研究——以星丰流域为例

ccording to the distribution of vegetation and impacts of human activities on underlying surface in Dongjiang’s red-soil hilly region, this paper chooses Xingfeng as a typical catchment, uses Washington DHSVM(Distributed Hydrology-Soil-Vegetation Model) on the basis of global information system(GIS), remote sensing (RS) technology, as well as field and laboratory experiments, realizes modeling of high resolution DHSVM. Hydrological observed data in 2004 to 2008 is used to calibrate and verify the model. The average Nash-Sutcliffe coefficient achieves 0.75, which shows a well application of this model in this basin. Perturbation analyse method is introduecd to fix on soil and vegetation parameters sensitivity of runoff and evapotranspiration. Then four extreme land cover scenarios, such as pure eucalyptus forest, broadleaf forest, mixed forest and shrub are simulated to reveal hydrological responses with the changes of different land use. Our conclusions are as follow. Assumed current scenario, mainly evergreen needleleaf forest, was instead of shrub, the change of annual runoff and evapotranspiration should be the most obvious, while average runoff increases 60% and evapotranspiration descreases 70.2% . Forest land cover has more soil moisture adjustment ability than shrub. Soil moisture content (SMC) changes most significantly in shrub in dry period. Therefore, forest degradation will increase the occurrance probability of drought and waterlog disasters. According to our study result, as eucalyptus planting area expands, basin hydrological process will be influenced obviously.. Our research has important significant for analyzing eco-hydrological processes and ecological environment effects under the changes of underlaying surface and climate in southern red soil slope field in China.