当地暴雨放大法水汽效率放大的研究与应用

Study and Application of Water Vapor and Efficiency Amplying for Local Storm Magnification Method

水汽效率放大法广泛应用于我国一级大型土石坝水电工程和核工程的短历时可能最大暴雨计算。为了研究该方法的基本原理并更好地适用于实际工程,对该方法涉及各参数的物理含义进行了详细阐述,对极大化参数的选取和合理性分析进行了说明,并应用于金沙江流域1d PMP计算。结果表明:水汽效率放大法对降水的两个基本物理因子(水汽因子和动力因子)同时进行了放大,一般可采用该方法推求的成果作为推荐成果;推求可降水量时代表性露点的选择应在时间和地区上具有代表性;该方法中暴雨效率间接反应了设计流域空气辐合上升运动的情况,是目前动力因子中最容易计算且精度较高的方法;该方法推求的PMP成果与选取的典型暴雨量无关,只与设计流域最大可降水量、可能最大暴雨效率和降水时段有关。

The amplification method of water vapor and efficiency is widely used in short-time PMP calculation in hydropower project and the nuclear engineering in China.In order to study the basic principle and better used in the project,the physical meaning the parameters were described in detail,choice and amplification of the parameters were introduced.It was applied to 1-day PMP calculation for the Jinsha River basin.The results show that the PMP calculated by this method can be generally used as the recommended results because this method includes the two basic factors for precipitation.The selection of representative dew points for precipitable water should be representative in time and area.The rainstorm efficiency indirectly reflects the upward convergence of the air in the design basin,and it is the most easily calculated and highly accurate method for the amplification of dynamic factors.The PMP results calculated by this method have nothing to do with the typical storm rainfall selected.They are only related to the maximum precipitable water,the maximum rainstorm efficiency and the precipitation period.