Highly Resolved Rainfall-Runoff Simulation of Retrofitted Green Stormwater Infrastructure at the Micro-Watershed Scale

authored by: Sami Towsif Khan, José Fernando Chapa Zumba, Jochen Hack
Abstract: Green Stormwater Infrastructure (GSI), a sustainable engineering design approach for managing urban stormwater runoff, has long been recommended as an alternative to conventional conveyance-based stormwater management strategies to mitigate the adverse impact of sprawling urbanization. Hydrological and hydraulic simulations of small-scale GSI measures in densely urbanized micro watersheds require high-resolution spatial databases of urban land use, stormwater structures, and topography. This study presents a highly resolved Storm Water Management Model developed under considerable spatial data constraints. It evaluates the cumulative effect of the implementation of dispersed, retrofitted, small-scale GSI measures in a heavily urbanized micro watershed of Costa Rica. Our methodology includes a high-resolution digital elevation model based on Google Earth information, the accuracy of which was sufficient to determine flow patterns and slopes, as well as to approximate the underground stormwater structures. The model produced satisfactory results in event-based calibration and validation, which ensured the reliability of the data collection procedure. Simulating the implementation of GSI shows that dispersed, retrofitted, small-scale measures could significantly reduce impermeable surface runoff (peak runoff reduction up to 40%) during frequent, less intense storm events and delay peak surface runoff by 5-10 min. The presented approach can benefit stormwater practitioners and modelers conducting small scale hydrological simulation under spatial data constraint.
External Organisation(s): Technische Universität Darmstadt
Type: Article
Journal: Land
Volume: 9
Publication date: 22.09.2020
Publication status: Published
Peer reviewed: Yes
ASJC Scopus subject areas: Global and Planetary Change, Ecology, Nature and Landscape Conservation
Sustainable Development Goals: SDG 11 - Sustainable Cities and Communities, SDG 15 - Life on Land
Electronic version(s): https://doi.org/10.3390/LAND9090339 (Access: Open)