| On the basis of the hydrometeorological data collected from the 29 precipitation stations, 5 runoff stations, and 1meteorological stations, we investigated the spatial-temporal change of the key hydrological variables (i.e., precipitation and runoff) in the past 50 years for 5 catchments within the Chifeng basin. We employed the rank-based Mann-Kendall trend test to quantitatively analyze the change trend and significance level for annual precipitation and streamflow. Then we adopted the VIC (Variable Infiltration Capacity)model to simulate the rainfall-runoff processes of above 5 catchments during the baseline period. Given the observed streamflow and the reconstructed natural streamflow, the effects of climate variability and human activities can be quantitatively separated. Results showed that approximately 98% of streamflow reduction during the changed period of 1980要2009 were attributed to human activities for the Chifeng basin, while the percentage due to the climate variability was only 2%. |
