关键词: 基流变化;气象因素;改进加里宁法;长江源区;

Abstract: Under the background of climate change，the water resources conditions in source region of the Changjiang River have undergone great changes，resulting in corresponding changes in river base flow.Based on the hydrological data and meteorological data from 1957 to 2020，the improved Kalinin method was used to calculate the base flow in the source region of the Changjiang River，analyzed the base flow changes law，and discussed the meteorological factors affecting the base flow changes and their corresponding influence degree.The research results showed that the average base flow of Zhimenda hydrological station in source region of the Changjiang River was 5.34 billion m3 from 1957 to 2020.Since 2008 the base flow began to increase abruptly.The increase of base flow in source region of the Changjiang River mainly included two reasons：one was the increase of precipitation，and the other was the increase of temperature.In the past 20 years，the source region of the Changjiang River had shown a trend of warming and humidification.Precipitation was the main source of river runoff，and increase of precipitation directly leaded to increase of groundwater recharge.The increase in temperature helped to melt glaciers，snow and permafrost，and promoted the replenishment of base flow.The research results can provide a scientific basis for revealing the composition of river runoff and its hydrological responded in source region of the Changjiang River under the conditions of climate change.

Key words: base flow variation；meteorological factor；improved Kalinin method；source region of the Changjiang River