不同降水产品在滦河流域径流模拟中的适用性

Applicability of different precipitation products to runoff simulations of Luanhe River basin

卫星降水产品和多源再分析数据对于水文模拟具有重要意义。本文基于地面实测降水数据,对全球降水观测计划多卫星降水产品(GPM IMERG)和中国区域地面气象要素驱动数据集(CMFD)再分析降水数据进行定量多尺度时空精度评估,并利用SWAT模型进行月尺度径流模拟,对比分析两种降水产品的水文效用。结果表明:在多时间尺度上,IMERG和CMFD数据与地面实测降水具有较高的相关性,二者分别呈现出对降水约3.7%和2.6%的高估;空间上,二者能够较好地描述降水的整体变化趋势。在弱降水的探测准确度上二者均需进一步提升。两种降水产品整体适用于滦河流域径流模拟,其中IMERG数据有效提高了雨量站稀疏流域的径流模拟精度,在水文模拟中具有良好的应用潜力。

Satellite precipitation products and multi-source reanalysis precipitation data are of great significance to hydrological simulations.Based on groundobserved precipitation data,this study evaluates the spatial and temporal accuracies of the Integrated Multi-Satellite Retrievals for Global Precipitation Measurement(GPM IMERG)dataset and the China Meteorological Forcing Dataset(CMFD)reanalysis precipitation data.By using the Soil&Water Assessment Tool(SWAT)to simulate monthly runoffs,applicability of the two precipitation products is compared.The results show that on multiple time scales,the IMERG data and CMFD data have high correlations with the observed precipitation,with overestimations by 3.7%and 2.6%,respectively;both can well describe the overall trend of precipitation in space but need further improvement on the accuracy of weak precipitation detection.Generally,they are applicable to simulations of the runoff in the Luanhe River basin.The GPM IMERG data can effectively improve the accuracy of runoff simulations for the basins with sparse rainfall stations,manifesting a good application potential in hydrological simulation.