Distinguishing human and climate influences on streamflow changes in Luan River basin in China

• We distinguished the effects of climate and human on annual and seasonal streamflow.
• The streamflow had a significant decreasing trend, with an abrupt change point in 1979.
• Human activity had larger effects on streamflow changes than climate.
• Reservoir regulation had larger effects on streamflow than land-use change.

Climate variability and human activities have received significant attention in recent years. We assessed streamflow record in the Luan River basin in the period 1956–2000 in response to climate variation and anthropogenic factors. Analyses of annual and seasonal series showed that the streamflow had a significant decreasing trend, with an abrupt change point in 1979. Human activity had more effects on streamflow changes than climate, for the change of annual streamflow, climate variability contributed 40.89%, and human activities contributed 59.11%; for the change of seasonal streamflow, climate variability contributed 43.53% (wet season) and 7.15% (dry season), and human activities contributed 56.47% (wet season) and 92.85% (dry season). In effects of human activity, reservoir regulation had a larger proportion than land-use change, it contributed 38.86% in the changes of annual streamflow, while land-use change contributed only 20.26%; and for the change of seasonal streamflow, reservoir regulation contributed 39.48% (wet season) and 52.14% (dry season), while land-use change contributed only 16.99% (wet season) and 40.71% (dry season).