ZENG Xiang-hong,JIANG Yuan-hua,YANG Qing-qing,et al.Effect of Rainfall Inter-event Time Definition on Sponge City Planning and Design[J].China Water & Wastewater,2020,36(21 21):102-109.
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Effect of Rainfall Inter-event Time Definition on Sponge City Planning and Design

China Water & Wastewater[ISSN:1000-4062/CN:12-1073/TU] volume: 第36卷 Number: 21 21 Page: 102-109 Column: Date of publication: 2020-11-01
Author(s):
ZENG Xiang-hong1; 2; JIANG Yuan-hua1; 2; YANG Qing-qing3; SHE Nian3; WU Hao1; 2; LIAO Yu-fang1; 4; DUAN Li-jie1; 2; DU Dong-sheng1; 4
(1. Key Laboratory of Meteorological Disaster Prevention and Mitigation in Hunan Province, Changsha 410118, China; 2. Hunan Climate Center, Changsha 410118, China; 3. China Machinery International Engineering Design & Research Institute Co. Ltd.， Changsha 410007, China; 4. Hunan Institute of Meteorological Sciences, Changsha 410118, China)
Keywords:
rainfall inter-event time definition; meteorological characteristics; watershed hydrological characteristics; sponge city
Abstract:
At present, rainfall inter-event time definition (IETD) adopted in sponge city planning and design is the upper limit of the rainfall duration (5-120 min) according to the design of urban drainage pipes and canals, which does not take into account the infiltration, retention and storage function of sponge city, and has certain limitation on planning, design and engineering application of sponge city. Therefore, an analysis method of coupling meteorological features and watershed hydrological characteristics from the perspective of urban basin was proposed, and IETD was defined as the time from the end of rainfall to the end of the runoff of the basin. This definition not only took into account the natural characteristics of urban watersheds, but also the functions of sponge city, which was thus applicable to most cities. The rainfall data of Changsha from 1990 to 2017 was analyzed and hydrologic simulation of two representative districts were carried out. IETD was significantly related to the catchment area, and was also affected by other factors such as impervious ratio and slope of the underlying surface. The median IETD of the catchment area was 4 h. Since most sponge cities planning and design were focused on catchment unit scale, therefore, it was reasonable to determine IETD of 4 hours in Changsha. Finally, the 4-hour IETD was applied to design a storm event. The results showed that the peak of the IETD rainstorm appeared significantly earlier than that of 2-hour IETD rainstorm.
Last Update: 2020-11-01