Premium
Urban Impacts on Extreme Monsoon Rainfall and Flooding in Complex Terrain
Author(s) -
Yang Long,
Smith James,
Niyogi Dev
Publication year - 2019
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2019gl083363
Subject(s) - terrain , environmental science , flood myth , hydrometeorology , flash flood , monsoon , urbanization , flooding (psychology) , convective storm detection , storm , climatology , urban climatology , outflow , meteorology , hydrology (agriculture) , urban climate , precipitation , geography , geology , psychology , cartography , psychotherapist , archaeology , geotechnical engineering , economic growth , economics
Abstract Hydrometeorological impacts due to urbanization for cities close to complex terrain are poorly understood due to the complexities of terrain‐related circulation and urban perturbations of atmospheric flow. In this study, we examine urban impacts on extreme monsoon rainfall and the resultant flooding over central Arizona based on high‐resolution atmospheric and hydrological model simulations. Strong positive rainfall anomalies at the urban‐rural interface downwind of the city are mainly related to dynamic effects (increased surface roughness) on convective outflow boundaries. Urban‐related thermodynamic disturbances slightly increase rain rates over the downtown core of Phoenix. Contrasting rainfall anomalies for two consecutive storm episodes highlight the importance of flow regime analysis in understanding urban impacts on extreme rainfall in complex terrain. Urban‐induced rainfall anomalies result in amplification of flood peak magnitudes by as much as a factor of 2 for Phoenix watersheds. Our results highlight the urban impacts on regional flood hydrology through land‐atmosphere interactions.