Abstract

In the key flood control area of the Poyang Lake Basin (China), over 80% of annual precipitation is concentrated in the rainy season. This study investigated the intraseasonal evolution and climatic characteristics of precipitation during the rainy season in the Poyang Lake Basin under the background of climate change. On the basis of the precipitation pattern, the rainy season was divided into three stages: the spring rainy season, Meiyu season, and summer rainy season. Generally, total precipitation and precipitation hours showed no significant trends of change, whereas precipitation intensity had an obvious trend of increase. In the spring rainy season, the trend of total precipitation was downward but not significant; however, owing to substantial reduction in precipitation duration, precipitation intensity was enhanced significantly. In the Meiyu season (summer rainy season), total precipitation increased significantly because of increased precipitation duration (precipitation intensity). The spatial distributions of total precipitation in the spring rainy season and Meiyu season were similar, i.e., precipitation occurred mostly in the east and less in the west; however, the spatial distributions of the change trends were opposite. In the summer rainy season, precipitation was concentrated primarily in the surrounding mountainous areas.

摘要

在鄱阳湖流域重点防洪区，年降水量的80%以上集中在雨季。研究了气候变化背景下鄱阳湖流域雨季降水的季内演化和气候特征。根据降水规律，将雨季划分为春季雨季、梅雨季和夏季雨季三个阶段。总降水量和降水小时数总体上无明显变化趋势，降水强度有明显增加趋势。春雨季降水总量呈下降趋势，但不显着；然而，由于降水持续时间大幅减少，降水强度显着增强。在梅雨季（夏季雨季），由于降水持续时间（降水强度）的增加，总降水量显着增加。春雨季和梅雨季总降水量的空间分布相似，即降水多在东部，西部较少；然而，变化趋势的空间分布却相反。夏季雨季，降水主要集中在周边山区。变化趋势的空间分布相反。夏季雨季，降水主要集中在周边山区。变化趋势的空间分布相反。夏季雨季，降水主要集中在周边山区。