Fig.7 Characteristics of sediment in Poyang Lake estuary during 1980-2020
4.2.3 Changes of Evaporation and Precipitation in Poyang Lake.
From 1977 to 2020, the evaporation of the dry season has an insignificant increasing trend (Z=0.56). Evaporation of flood season has a significant downward trend (Z=-2.14), declining rate being4.62 *10-1mm/a, and change point at 1992. The Pearson analysis test result shows that evaporation and lake area has no significant correlativity. In the dry season, the correlation coefficient is 0.11. In the flood season, the correlation coefficient is 0.06. (Figure 8)
In Figure 9, from 1977 to 2020, flood season precipitation had an insignificant downward trend (Z=-0.41), and dry season precipitation significantly increased (Z=2.48). The correlation coefficient of flood season precipitation and area is 0.31, at a 99% confidence level. In the dry season, the correlation coefficient is insignificant.