Impact of the spatial distribution of imperviousness on the hydrologic response of an urbanizing basin

Abstract

Abstract:An event-based model is used to investigate the impact of the spatial distribution of imperviousness on the hydrologic response of a basin characterized by an urban land use. The impact of the spatial distribution of imperviousness is investigated by accounting for its location within the basin when estimating the generated runoff and the hydrologic response. The event model accounts for infiltration and saturation excess; the excess runoff is routed to the outlet using a geomorphologic unit hydrograph. To represent the spatial distribution of rainfall and imperviousness, radar and remotely derived data are used, respectively. To estimate model parameters and analyse their behaviour, a split sample test and parameter sensitivity analysis are performed. From the analysis of parameters, we found the impervious cover tends to increase the sensitivity and storm dependency of channel routing parameters. The calibrated event model is used to investigate the impact of the imperviousness gradient by estimating and comparing hydrographs at internal locations in the basin. From this comparison, we found the urban land use and the spatial variability of rainfall can produce bigger increases in the peak flows of less impervious areas than the most urbanized ones in the basin. To examine the impacts of the imperviousness pattern, scenarios typifying extreme cases of sprawl type and clustered development are used while accounting for the uncertainty in parameters and the initial condition. These scenarios show that the imperviousness pattern can produce significant changes in the response at the main outlet and at locations internal to the overall watershed. Overall, the results indicate the imperviousness pattern can be an influential factor in shaping the hydrologic response of an urbanizing basin.

Evaluating the impact and risk of pluvial flash flood on intra-urban road network: A case study in the city center of Shanghai, China

“…interruption of public services and economic activities), especially in the urbanized areas around the world (e.g. Ramos et al 2005;Mejia and Moglen 2010;Smith et al 2012;Wright et al 2012). PFF is a rapid flood caused by heavy rain and can be distinguished from a regular pluvial flood by a short timescale, generally less than six hours.…”

Effects of Impervious Surface on the Spatial Distribution of Urban Waterlogging Risk Spots at Multiple Scales in Guangzhou, South China

“…Previous studies found that the composition of the impervious surface (the impervious surface area) reduced the total infiltration of water into the surface and, thereby, increased the surface runoff and peak discharge, which ultimately raised the associated risk of urban flooding [27,28]. In addition, several studies showed that the spatial configuration of the impervious surface influenced surface runoff and the potential urban flood risk, as well [27,29,30]. However, most previous studies primarily highlighted the importance of the location of the impervious surface (e.g., upstream, midstream or downstream) in an urban watershed or catchment to define the influence of the spatial configuration of the impervious surface.…”

Urban Land Pattern Impacts on Floods in a New District of China

“…The effects of urbanization on land processes can be an important control, and later, the research focused on the implementation of urban planning technologies, such as LID (Low Impact Development) in North America [24,25], for which, equivalent terms such as sustainable urban drainage systems (SUDS) in the United Kingdom, water-sensitive urban design (WSUD) in Australia [26] and the Low Impact Urban Development Design (LIUDD) [27], is an alternative approach to stormwater management and avoid negative effects of conventional urban land redevelopment by using the catchment context as the design framework and encouraging the minimization and the clustering of urbanization areas to maximize surface permeability. A catchment-based structure planning approach needs to involve all professional sectors and a nested hierarchy of units for design and management [28], and should begin whilst a basin is still in its natural state [29][30][31].…”