Land use and climate change are recognized as two major drivers affecting surface streamflow. This is also the case for the Chinese Loess Plateau, where several land restoration projects have changed land cover in recent decades. Therefore, this study looked into how streamflow evolved on the Loess Plateau and how land use and climate change have contributed to this change. This was done through a meta-analysis  on hydrological and meteorological data from 22 publications covering 25 different watersheds in the Loess Plateau.

The results indicate a streamflow decrease in 41 out of 52 case studies. Over all studies, streamflow reduction was estimated to be −0.46 mm/year. Precipitation did not change in most studies. Land use change was estimated to have 63.52% impact on the streamflow reduction, and climate change seemed to cause 36.48% of the impact. They also found that the larger the soil and water conservation area , the higher the streamflow reduction.

The conclusion is therefore that in the Chinese Loess Plateau, streamflow shows a decreasing trend and land restoration is the major cause of this reduction.

Photo: Loess plateau before (1995, left) and after major landscape restoration (2009, right)