Analysis the Hydrological Situation of the Influx Runoff Series for Poyang Lake

According to historical observed data for the runoff into the Poyang Lake, the analysis of runoff into the Poyang Lake about 50 years was conducted. The results showed that the five rivers runoff for the influx into the Poyang Lake, were decreased since 2002, and the runoff decline phenomenon like this has appeared in the 60's and 80's. About the runoff annual distribution, the uneven distribution was detected. The sum of the monthly runoff from April to July account for 46%∼69% about the entire year, and in the dry season, the sum of the monthly runoff from October to next year January only account for 12%∼23%. About the each monthly runoff series of the five rivers from 1956 to 2008, it was observed that during the flood season the dispersion coefficient of the series is small, and in the non-flood season the dispersion coefficient of the series is bigger. It illuminated that the monthly runoff series were changer in the non-flood than the flood season and the increased human activities may be the major factor.