Flood frequency in China's Poyang Lake region: Trends and teleconnections

摘要

Poyang Lake in Jiangxi Province is the largest freshwater lake in China and is historically a region of significant floods. Annual events of peak lake stage and of severe floods have increased dramatically during the past few decades. This trend is related primarily to levee construction at the periphery of the lake and along the middle of the Changjiang (Yangtze River), which protects a large rural population. These levees reduce the area formerly available for floodwater storage resulting in higher lake stages during the summer flood season and catastrophic levee failures. The most severe floods in the Poyang Lake since 1950, and ranked in descending order of severity, occurred in 1998, 1995, 1954, 1983, 1992, 1973, and 1977. All of these floods occurred during or immediately following El Nino events, which are directly linked to rainfall in central China. The 2-year recurrence interval for maximum annual lake stage during El Nino years is 1.2 m higher than during non-El Nino years. The 10-year recurrence interval is 1.4 m higher during El Nino years than during non-El Nino years. Copyright (C) 2006 Royal Meteorological Society.