长江中下游沿江地区暴雨过程综合评估模型及应用

摘要

Based on the 87 stations selected along middle and lower reaches of the Changjiang River, and high-density surface meteorological precipitation daily data during 1957--2007, the statistical methods are used to analyze the rainstorm process, and establish a rainstorm process impact assessment model. First select average rainfall, rainfall intensity, coverage and duration as four indicators, each indicator uses the normal transformation or gamma distribution to fit, then uses the appropriate distribution's inverse function of probability density function to determine the theoretical values of return period as the grade level standards, which can be divided into five levels. Finally, a composite assessment model of rainstorm process is set up. In this paper the model is applied to assessment of five rainstorm processes from the end of June to August in 1999, and the results show that the effect is good, and can be put into operation.%选取长江中下游沿江地区87个站点，利用1957—2007年中国高密度台站地面日降水资料，对长江中下游沿江地区暴雨过程的历史资料进行统计分析，建立长江中下游沿江地区暴雨过程综合评估模型。首先选取平均降水量、降水强度、覆盖范围和持续时间4个指标，并对每个指标进行了正态化转化或Г分布拟合，然后利用相应的分布概率密度函数的反函数确定数年一遇的概率等级作为等级标准，将长江中下游沿江地区的暴雨过程划分为5个等级，最终运用权重分析法建立了暴雨过程综合评估模型。应用此模型对1999年6—8月的5次暴雨过程进行了试评估，结果表明，该模型评估效果较好，可以在实际业务中应用。