Runoff Variation Law and Its Response to Climate Change in the Headstream Area of the Keriya River Basin, Xinjiang

Based on the runoff and meteorological data of Langan (兰干) Hydrological Station from 1957 to 2009 in Keriya (克里雅) River, the periodicities, abrupt changes, and trends of climate factors and runoff were investigated by wavelet analysis and nonparametric test; then, the future change of the annual runoff was predicted by a periodic trend superposition model. In succession, the influencing volumes of climate change on the annual runoff were separated from the observation values of the annual runoff in Keriya River. The results show that (1) temperature series increased significantly, while the annual runoff and precipitation of Keriya River increased insignificantly at the significant level of α=0.05; (2) the common periods of 9 and 15 years existed in the annual runoff evolution process, and the primary periods of temperature and precipitation were 9 and 22 years and 9 and 13 years, respectively; (3) the annual runoff did not vary simultaneously with the abrupt change of climate factors in the headstream; the abrupt points of annual runoff and temperature are at 1998 and 1980 year, and that of precipitation is not so significant; and (4) the annual runoff will experience a decrease trend in the future period; the total increasing volume owing to climate change is 23.154×10⁸ m³ in the headstream during the period of 1999–2009; however, the stream flow has been nearly utilized completely due to the human activities in the mainstream area of Keriya River.