Abstract:

Based on the 45 years measured data of runoff series from the Manhao Station that is the main controlling hydrological station in the downstream of Honghe River，the basic characteristics of runoff variability have been analyzed by using MannKendall，cluster technique method，accumulated deviation and other statistical methods.The results showed that the measure runoff distribution was nonuniform intra year and small change in years，and the Cv of annual runoff is 0263.There is a slow ascending trend for annual runoff and the stages of variety process are clear.Measure runoff of Manhao Station was reverted to natural runoff and the results showed that the mean water resources consumption was accounted for 292%.Both annual runoff and runoff coefficient have jumps of increase occurred around 1965 and 1994.On the contrary，both annual precipitation and evaporation have no jump.The variability of NDVI indicated that vegetation in the downstream of Honghe River was destroyed so severely in 1993.Consequently，the jumps of runoff were major influenced by activity of humanity while the trend change was affected by the precipitation.

Key words: downstream of Honghe River, runoff, serial characteristics, variability