ABSTRACT

Moments of rainfall spatial variability, which quantify how flood response time scales are affected when spatially variable rainfall is considered, compared to when rainfall is spatially uniform, have been suggested as a useful tool for forecasters to guide their choice between lumped or distributed rainfall information for runoff modelling. However, the approaches used to evaluate the validity of moments suffer from limitations. Hence, we adopt a novel approach for their evaluation by comparing moments to the relationship between observed hydrograph characteristics generated by spatially variable and by uniform rainfall events in the same catchment. We further investigate the usefulness of moments by testing whether the performance of a lumped hydrological model for events classified by moments as spatially variable is lower than for uniform events. Results confirmed that moments can identify spatially variable events and characterize differences in hydrograph features compared to uniform events, providing a useful tool for forecasters.

摘要

与降雨空间均匀时相比，降雨空间变异时刻量化了考虑空间可变降雨时洪水响应时间尺度的影响，已被建议作为预报员在集中或分布式降雨信息之间进行选择的有用工具径流建模。然而，用于评估矩有效性的方法存在局限性。因此，我们采用一种新颖的方法来评估它们，将矩与由空间变量和同一流域中的均匀降雨事件产生的观测水文曲线特征之间的关系进行比较。我们通过测试集总水文模型对按矩分类为空间变量的事件的性能是否低于均匀事件的性能来进一步研究矩的有用性。结果证实，与均匀事件相比，矩可以识别空间可变事件并表征水文特征的差异，为预报员提供了有用的工具。