Impacts of climate variability on the streamflow for the recent 50 years in the Min River basin, China

This study was conducted to investigate the response of streamflow to climate variability in the Min River Basin, China. The temporal trends were explored for streamflow, precipitation and temperature during 1960-2000 by Mann-Kendall test, and impacts of climate change on streamflow were also investigated by the climatic elasticity analysis. The results show that: (1) the annual streamflow in the Min River basin presents an upward trend, and the runoff in the non-flood season contributes a lot to this increase. The autumn and winter streamflow show an increasing trend for most of time, and it lead to the significant increasing trend in the non-flood-season streamflow. The summer streamflow is on the increase while spring is on the decrease after 1990s. (2) both precipitation and temperature of the basin increase for the study period, especially for temperature. And the upward trend of runoff is more evident than that of precipitation. (3) the elasticity coefficients of runoff to precipitation, epsilon(P), from 1960 to 2006 by 2 nonparametric methods are 0.91 and 0.98 respectively, and the elasticity coefficients of runoff to temperature, epsilon(T), are 1.0 and 0.91 respectively. (4) there is a decreasing trend in the epsilon(P) while the epsilon(T) was high from the late 1980s to the mid 1990s in the Min River basin. Moreover, human activities have played an important role in the changes of runoff during recent years, which results in the decrement of precipitation elasticity. Regional warming leads to the acceleration of water cycle, thus the temperature elasticity increased.