Abstract:
In this paper, the nonparametric MannKendallSneyers test was used to analyze the stationarity of the annual streamflow records of Baoqing hydrological station and Caizuizi hydrological station in Naoli River watershed from 1956 to 2005. The empirical model which shows the relationship between rainfall and streamflow was established, and the model was used to assess the impacts of climate changes and human activities on annual streamflows. The result shows that the whole period of annual streamflows from 1956 to 2005 can be divided into two phases: baseline period (1956—1967) and changed period (1968—2005). During the changed period，the interannual and intraannual variability of streamflows changed significantly, and the interannual variability of streamflows was mainly caused by human activities, about 40 percent was caused by climate changes.

Key words: Naoli River, streamflow, marsh, climate change, Sanjiang Plain, Naoli River, streamflow, marsh, climate change