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【Objective】 The Kaidu River is a tributary of the Tarim River, located in northwestern China. This paper analyzes the evolution of runoff in its source area as well as its determinants. 【Method】 The study is based on meteorological and hydrological data measured over the past 60 years from the area. The evolution of the runoff is analyzed using the Mann - Kendall examination, R/S method, order clustering method, and the method of wavelet analysis. The impact of climate change and anthropogenic activities on the runoff is calculated using the double accumulation curve method, the cumulative slope change rate method, and the climate elastic coefficient method. 【Results】 ①From 1960 to 2019, the annual runoff in the area had been increasing at an average rate of 1.714×108 m3/10 a, with the Hurst index being 0.83. The runoff is found to have three identified periods of 36 years, 21 years, and 9 years; additionally, an abrupt change in the runoff is also identified in 1995. ②Over the past 60 years, temperature and precipitation in the area had increased at a rate of 0.239 ℃/10 a and 7.670 mm/10 a, respectively, with their associated Hurst index being 0.85 and 0.83, and the correlation coefficients being 0.560 and 0.598, respectively. ③The contribution of climate to the change in the runoff calculated by the double cumulative curve method, the cumulative slope change rate method and the climate elasticity coefficient method is 89.9%, 73.1% and 43%, respectively, while the associated contribution of anthropogenic activities calculated by the three methods to the change is 10.1%, 26.9% and 57%, respectively; their associated errors for the base runoff are 2.1%, 0.2% and 4.1%, respectively. 【Conclusion】 The annual runoff in the source area of the Kaidu River over the past 60 years has increased significantly and the contribution to this change is mainly from climate change. |
