Hydrological Response to Natural and Anthropogenic Factors in Southern Taiwan

Attribution of Streamflow Variations in Southern Taiwan

Climate change and anthropogenic activity are the main factors impacting the hydrological environment. For sustainable water utilization, identifying the impact contribution of these two factors on the streamflow variations is an important topic in recent research. In this study, seven river basins in southern Taiwan were selected as the study area to evaluate the annual streamflow from 1980 to 2017. The decomposition and elasticity methods based on the Budyko hypothesis were applied to quantify the contribution of climate and anthropogenic factors to the streamflow variations. In addition, the normalized difference vegetation index (NDVI) was used to represent the actual situation of land cover and verify the parameters in the Budyko equation. The two quantitative methods consistently demonstrated that the streamflow variations from pre- to post-period occurred due to the climate factor. The elasticity coefficient of variables demonstrated that the streamflow change is more sensitive to precipitation and this influence reduces from pre- to post-period as the streamflow increase. In the NDVI variations, except for the Yanshui and the Linbain rivers, the Budyko equation parameters changed consistently with NDVI. The present study provides effective results on the contribution of streamflow variations in southern Taiwan to serve as a reference for future water management.