面雨量计算不确定性对新安江模型径流模拟的影响研究

降雨是流域水资源最直接的来源,其过程影响流域水资源的产生和汇聚,对流域的径流过程影响显著。基于新安江模型,以涪江流域为研究对象,采用泰森多边形法、反距离权重法进行面雨量计算,模拟2007-2012年的日径流系列,研究了雨量站网密度、降雨空间插值方法对面雨量计算结果及径流模拟精度的影响,在此基础上进一步探讨了面雨量计算相对偏差与径流量模拟相对偏差之间的关系。结果表明:雨量站点越多面雨量计算的不确定性越小,径流模拟精度越高;在涪江流域内插值站点数目较少时,反距离权重法的径流模拟精度更优,站点数目较多时,泰森多边形法的径流模拟精度略优于反距离权重法;径流量模拟相对偏差与面雨量计算相对偏差不存在明显的相关关系,随着面雨量计算相对偏差的增大,径流量模拟相对偏差呈震荡变化。

Research on the Effect of Uncertainty in Regional Rainfall Calculation on Runoff Modeling Based on XAJ Model

Precipitation is the most direct source of water resources in the basin with affecting runoff process as well as the generation and convergence of water resources.In this paper,the thiessen polygon method and inverse distance weight method are used to calculate the surface rainfall.The XAJ model is used to simulate the daily runoff series from 2008 to 2012 in Fujiang River basin.On this basis,the influence of rain-gauge network intensity and interpolation methods on results of area rainfall and runoff simulation accuracy is studied,and the relationship between relative deviation of area rainfall calculation and runoff simulation relative deviation is further discussed.The results show that the more rainfall stations,the less the uncertainty of area rainfall calculation,the higher the accuracy of runoff simulation.When there are few rainfall stations for interpolation in Fujiang Basin,the accuracy of runoff simulation results by inverse distance weight method is better.When there are more rainfall stations for interpolation,the accuracy of runoff simulation results by thiessen polygon method is slightly better than that by inverse distance weight method.There is no obvious correlation between the runoff simulation relative deviation and the area rainfall calculation relative deviation.With the increase in the regional rainfall calculation relative deviation,the runoff simulation relative deviation shows a oscillating change.