摘要
提升城市暴雨内涝防治精细化水平是解决城市洪涝问题的关键。采用16种不同时空分辨率的降雨产品,利用暴雨时空异质性评估指标和随机暴雨移置法,在上海地区定量评估降雨数据精度对暴雨事件时空变异性诊断和频率分析的影响。研究发现利用低精度降雨数据得到的年最大暴雨序列发生时间延迟、降水量低估,暴雨过程不均匀性提升、空间不均匀性降低;在不同重现期下,降雨数据精度对频率分析结果影响有显著差异,重现期越大,低精度数据带来的低估程度越大;时间精度的影响占主导地位,可达空间精度的5倍。在城市暴雨洪涝研究中有必要采用更高精度的降雨数据,建议与研究区域类似的小型城市地区在防洪设计中使用精度达(12 h、0.05°)或以上的降雨数据。
Improving the accuracy and refinement level of urban flood management is the key to solving the urban flooding.The purpose of this paper is to quantitatively assess the role of rainfall resolution in detecting rainfall variability and performing rainfall frequency analyses(RFA).A total of 16 rainfall products with a variety of space-time resolutions were used to obtain RFA results in Shanghai,China.Results are based on diagnostic indicators of rainfall variability and the stochastic storm transposition method.The results indicate that storm magnitudes are underestimated when coarse space-time resolutions are used.Furthermore,the use of low-resolution data results in a lagged estimation of storm occurrence and an under-and overestimation of rainfall variations.Depending on the return period,the rainfall resolution has a significant impact on the RFA outputs:coarser data resolution and longer return periods tend to underestimate the intensity-duration-frequency curves.It is also evident that temporal resolution has a greater impact than spatial resolution,as it accounts for five times as much of the effect.These results emphasize the importance of high-resolution rainfall data for the analysis of extreme rainfall intensities,particularly in relation to urban flooding.For flood control design purposes in urban areas,we recommend using rainfall data with a resolution of 12 h and 0.05°or finer.
作者
庄琦
刘曙光
周正正
ZHUANG Qi;LIU Shuguang;ZHOU Zhengzheng(College of Civil Engineering,Tongji University,Shanghai 200092,China;Key Laboratory of Cities′Mitigation and Adaptation to Climate Change in Shanghai,China Meteorological Administration,Shanghai 200030,China)
出处
《水科学进展》
EI
CAS
CSCD
北大核心
2023年第3期398-408,共11页
Advances in Water Science
基金
国家自然科学基金资助项目(42271031,51909191)。
关键词
城市极端降雨
时空分辨率
不确定性
频率分析
IDF曲线
上海
urban extreme rainfall
spatiotemporal resolution
uncertainty
frequency analysis
IDF curve
Shanghai
