RainSim: A spatial-temporal stochastic rainfall modelling system
RainSim: A spatial-temporal stochastic rainfall modelling system
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DOI：
10.1016/j.envsoft.2008.04.003
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发表时间：
2008-12
期刊：
影响因子：
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通讯作者：
A. Burton;C. Kilsby;H. Fowler;P. Cowpertwait;P. O'Connell
中科院分区：
文献类型：
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作者：
A. Burton;C. Kilsby;H. Fowler;P. Cowpertwait;P. O'Connell
RainSim V3是一款强大且经过充分测试的随机降雨场生成器，在广泛的气候和终端用户应用中成功使用。雨量场或多点时间序列可以从时空的Neyman-Scott矩形脉冲过程中抽样：风暴事件以时间泊松过程的形式发生；每个风暴事件使用平稳的空间泊松过程触发雷诺单体的产生；暴雨单体在时间上聚集滞后于风暴事件；每个雷诺单体在其圆形范围内和整个生命周期内均匀地贡献降雨；暴雨单体的滞后、持续时间、半径和强度是随机变量；地形效应是由雨量场的非均匀尺度引起的。通过对参数可选对数变换的五种方案的评估，确定了稳健有效的模型校正数值优化方案。对于单站点应用，选择了具有收敛准则的对数参数混洗复杂进化算法(LnSCE)；对于空间应用，选择了有限努力重新启动的LnSCE算法。描述了新的目标函数，并将其用于改进模型校正。确定了线性和二次表达式，它们可以减少校准中使用的干燥小时和干燥天数的拟合概率和模拟概率之间的偏差。实现了平均雨量统计的精确拟合，并进行了演示。对荷兰/比利时边界的Dommel集水区的应用表明，改进后的模型能够匹配观测到的统计数据和极值。
RainSim V3 is a robust and well tested stochastic rainfall field generator used successfully in a broad range of climates and end-user applications. Rainfall fields or multi-site time series can be sampled from a spatial–temporal Neyman–Scott rectangular pulses process: storm events occur as a temporal Poisson process; each triggers raincell generation using a stationary spatial Poisson process; raincells are clustered in time lagging the storm event; each raincell contributes rainfall uniformly across its circular extent and throughout its lifetime; raincell lag, duration, radius and intensity are random variables; orographic effects are accounted for by non-uniform scaling of the rainfall field. Robust and efficient numerical optimization schemes for model calibration are identified following the evaluation of five schemes with optional log-transformation of the parameters. The log-parameter Shuffled Complex Evolution (lnSCE) algorithm with a convergence criterion is chosen for single site applications and an effort limited restarted lnSCE algorithm is selected for spatial applications. The new objective function is described and shown to improve model calibration. Linear and quadratic expressions are identified which can reduce the bias between the fitted and simulated probabilities of both dry hours and dry days as used in calibration. Exact fitting of mean rainfall statistics is also implemented and demonstrated. An application to the Dommel catchment on the Netherlands/Belgian border illustrates the ability of the improved model to match observed statistics and extremes.