The Effect of QPF on Real-Time Deterministic Hydrologic Forecast Uncertainty
The Effect of QPF on Real-Time Deterministic Hydrologic Forecast Uncertainty
复制标题
QPF 对实时确定性水文预报不确定性的影响
DOI：
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发表时间：
2019
影响因子：
3.8
通讯作者：
R. Dymond
中科院分区：
文献类型：
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作者：
T. Adams;R. Dymond
定量降水预报（QPF）在水文预报中的应用很常见，但QPF存在相当大的误差。当QPF作为一种模型强迫项包含在水文预报过程中时，显著的误差会在水文预测中传播。由此产生两个问题：1）由此产生的观测到的水文预报误差是否足够大，以至于表明在预报过程中应使用零QPF；2）如果表明应使用非零QPF，那么应该使用多少个时段（小时）的QPF（1、6、12……72小时）？此外，是否存在预报条件使得QPF的使用应该有所不同？本研究展示了两个实时水文预报实验的结果，重点关注美国国家海洋和大气管理局/国家气象局俄亥俄河预报中心（OHRFC）。这些实验依赖于39个预报点位置的子流域的预报，这些子流域在流域面积、俄亥俄河流域内的地理位置以及流域响应时间方面各不相同。2007年8月10日至2009年8月31日期间涵盖所有流量范围的一个实验结果表明，非零QPF产生的水文预报误差比零QPF更小。2009年1月23日至2010年9月15日的第二个实验表明，对于洪水预报，QPF应限制在6 - 12小时的时长。超过12小时，所有预报范围内的水文预报误差都会大幅增加，而且洪水预报的误差要大得多。只有对于非洪水预报，较长时长的QPF产生的预报误差比短时长的QPF更小。实验结果表明与美国国家气象局2001年4月至2016年10月针对OHRFC的预报验证统计数据是一致的。
The use of quantitative precipitation forecast (QPF) in hydrologic forecasting is commonplace, but QPF is subject to considerable error. When QPF is included as a model forcing in the hydrological forecast process, significant error propagates through the hydrologic predictions. Two questions arise: 1) are the resulting observed hydrologic forecast errors sufficiently large to suggest the use of zero QPF in the forecast process, and 2) if the use of nonzero QPF is indicated, how many periods (hours) of QPF (1, 6, 12, …, 72 h) should be used? Also, do forecast conditions exist under which the use of QPF should be different? This study presents results from two real-time hydrologic forecast experiments, focused on the NOAA/NWS Ohio River Forecast Center (OHRFC). The experiments rely on forecasts from subbasins at 39 forecast point locations, ranging in drainage area, geographic location within the Ohio River Valley, and watershed response time. Results from an experiment, spanning all flow ranges, for the 10 August 2007–31 August 2009 period, show that nonzero QPF produces smaller hydrologic forecast error than zero QPF. A second experiment, 23 January 2009–15 September 2010, suggests that QPF should be limited to 6–12-h duration for flood forecasts. Beyond 12 h, hydrologic forecast error increases substantially across all forecast ranges, but errors are much larger for flood forecasts. Increased durations of QPF produce smaller forecast error than shorter QPF durations only for nonflood forecasts. Experimental results are shown to be consistent with NWS April 2001–October 2016 forecast verification statistics for the OHRFC.