Premium
The complexities of urban flood response: Flood frequency analyses for the Charlotte metropolitan region
Author(s) -
Zhou Zhengzheng,
Smith James A.,
Yang Long,
Baeck Mary Lynn,
Chaney Molly,
Ten Veldhuis MarieClaire,
Deng Huiping,
Liu Shuguang
Publication year - 2017
Publication title -
water resources research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.863
H-Index - 217
eISSN - 1944-7973
pISSN - 0043-1397
DOI - 10.1002/2016wr019997
Subject(s) - flood myth , impervious surface , environmental science , 100 year flood , hydrology (agriculture) , flash flood , watershed , flood forecasting , surface runoff , hydrometeorology , land cover , storm , land use , precipitation , geography , meteorology , geology , ecology , civil engineering , geotechnical engineering , archaeology , machine learning , computer science , engineering , biology
We examine urban flood response through data‐driven analyses for a diverse sample of “small” watersheds (basin scale ranging from 7.0 to 111.1 km 2 ) in the Charlotte Metropolitan region. These watersheds have experienced extensive urbanization and suburban development since the 1960s. The objective of this study is to develop a broad characterization of land surface and hydrometeorological controls of urban flood hydrology. Our analyses are based on peaks‐over‐threshold flood data developed from USGS streamflow observations and are motivated by problems of flood hazard characterization for urban regions. We examine flood‐producing rainfall using high‐resolution (1 km 2 spatial resolution and 15 min time resolution), bias‐corrected radar rainfall fields that are developed through the Hydro‐NEXRAD system. The analyses focus on the 2001–2015 period. The results highlight the complexities of urban flood response. There are striking spatial heterogeneities in flood peak magnitudes, response times, and runoff ratios across the study region. These spatial heterogeneities are mainly linked to watershed scale, the distribution of impervious cover, and storm water management. Contrasting land surface properties also determine the mixture of flood‐generating mechanisms for a particular watershed. Warm‐season thunderstorm systems and tropical cyclones are main flood agents in Charlotte, with winter/spring storms playing a role in less‐urbanized watersheds. The mixture of flood agents exerts a strong impact on the upper tail of flood frequency distributions. Antecedent watershed wetness plays a minor role in urban flood response, compared with less‐urbanized watersheds. Implications for flood hazard characterization in urban watersheds and for advances in flood science are discussed.