Mann—Kendall方法在长江汉口站水沙特性

River flow and sediment regime has been altered to some extent by the construction of water projects, as a consequence, the safety and stability of river ecosystem have been affected. Therefore, it is very important to study changes in river flow and sediment characteristics. The paper selected Hankou hydrological stations as case study sites, and daily flow discharge data from the station during 1960~2003 respectively and sediment concentration data during 1952-2003 respectively were collected. Based on Mann-Kendall rank statistical test, the trends and abruption in annual sediment load, annual mean flow discharge, and sediment load and mean flow discharge in flood and non-flood seasons were explored at these three hydrological stations. The results reveal that annual flow discharge at Hankou shows an increasing trend. Sediment load at the station presents a decreasing trend, and the decreasing trend becomes more significant since 1980s, particularly from 1984. The mean flow discharge of Hankou station show a slight increasing trend in flood season. The output of this paper provides a basis for the assessment of impacts of water projects on the Yangtze River ecosystem health.