Influence of operation of Three Gorges Reservoir on flow regime in mid-lower reaches of Yangtze River

In order to evaluate the influence of human activities on river runoff,the range of variability approach(RVA) is adopted to assess the flow regime of the middle and lower reaches of Yangtze River after the operation of Three Gorges Reservoir.Based on the daily flow data from 1961 to 1985 and 2003 to 2008 at the 6 downstream stations of Three Gorges Reservoir,by analyzing the median and coefficient of deviation of the 32 indicators of hydrologic alteration(IHA),we conclude that the influence degree is different in dry and wet seasons,and decreases from upper to lower reach.In general,the influence of operation of Three Gorges Reservoir on runoff is moderate.