Accuracy of radar rainfall estimates for streamflow simulation
Accuracy of radar rainfall estimates for streamflow simulation
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DOI：
10.1016/s0022-1694(02)00137-3
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发表时间：
2002-10-01
影响因子：
6.4
通讯作者：
Borga, M
中科院分区：
文献类型：
--
作者：
Borga, M
这项工作的目的是分析误差的影响，雷达降雨量估计的卫星径流模型。这一问题是通过应用雷达降雨量估计连续，集总径流建模的布鲁流域，在英格兰西南部的中型盆地，在两年半的时间。这项研究的重点是雷达降雨误差与范围相关的偏差，由于垂直剖面的反射率和平均场偏差，由于系统误差的雷达校准和偏置反射率降雨率的关系。通过一个概念性的水文模型，通过使用各种雷达降雨处理方案获得的平均面雨量估计的基础上模拟径流。这些模拟进行了评估，并与相应的径流模拟从一个密集的雨量计网络。比较表明，雷达误差可能会妨碍使用未经调整的雷达估计径流建模。雷达降水校正显著改善了模式的模拟效果，校正后的模拟效率提高了30%。雷达驱动的模拟与观测到的放电数据的比较显示，最低的雷达扫描（调整）的模拟效率为0.75，而较高的雷达扫描的模拟效率较低。结果表明，使用雷达降雨估计尽可能接近地面的重要性和相当大的影响，垂直变化的反射率对径流模拟的影响。(C)2002 Elsevier Science B.V.保留所有权利。
The aim of this work is to analyse the impact of errors in radar rainfall estimates on rainfall-runoff modelling. This issue is addressed through application of radar rainfall estimates for continuous, lumped rainfall-runoff modelling of the Brue catchment, a mid-sized basin in South-West England, over a two and a half-year period. The study is focused on radar rainfall errors associated with range-related bias due to the vertical profile of reflectivity and with mean-field bias due to systematic errors in the radar calibration and biased reflectivity-to-rainrate relationship. Streamflow is simulated through a conceptual hydrological model based on mean areal rainfall estimates obtained by using various radar rainfall processing scenarios. These simulations are evaluated and compared with corresponding streamflow simulations from a dense raingauge network. The comparisons show that radar errors may preclude the use of unadjusted radar estimates for runoff modelling. Radar rainfall adjustment significantly improves model results with simulation efficiency increasing up to 30% after adjustment. Comparison of radar-driven simulations with observed discharge data reveals a simulation efficiency of 0.75 for the lowest radar scan (adjusted), whereas simulation efficiencies are lower for higher radar scans. The results reveal the critical importance of using radar rainfall estimates as close as possible to the ground and the considerable impact that effects of vertical variability of reflectivity have on runoff simulation. (C) 2002 Elsevier Science B.V. All rights reserved.