Abstract
Stormwater runoff in the USA is a main driver of non-point source pollution and other major problems for urbanizing areas, and runoff effects will be exacerbated by the increased frequency and intensity of heavier storm events that are projected as climate changes. The purpose of this paper is to consider how increased rainfall from storms could influence direct stormwater runoff in urbanizing watersheds. As part of a recent research project in coastal Beaufort County, South Carolina, USA, we applied the Stormwater Runoff Modeling System (SWARM) to model various combinations of development levels and climate change scenarios. SWARM single-event output showed dramatic increases in runoff volume and rate, in some cases almost doubling under moderate climate change scenario and tripling under severe climate change scenario. In all cases, modeled impacts from climate change exceeded those of development. By quantifying stormwater runoff based on climate change scenarios within the context of development, the findings add to the recognition that they must be considered together when projecting changes in watershed hydrology and that climate change effects potentially exceed those of development.
Highlights
Half of the Earth’s human population lives in urban areas [1], and the impervious surfaces associated with urbanization decrease infiltration of rainfall into soils and increase surface runoff, effects that will be amplified by heavier storms that are projected to be very likely with climate change [2,3]
The two smaller watersheds showed the greater range in impervious cover—Wallace was the least developed at 1% impervious cover, and Battery was the most developed at 30%
Moderate and severe climate change scenarios are based on a 10% increase in rain at the semi-wetter antecedent runoff conditions (ARC) and a 20% increase in rain at the wetter ARC, respectively
Summary
Half of the Earth’s human population lives in urban areas [1], and the impervious surfaces associated with urbanization decrease infiltration of rainfall into soils and increase surface runoff, effects that will be amplified by heavier storms that are projected to be very likely with climate change [2,3]. In the USA, stormwater runoff is a main driver of non-point source pollution in urbanized areas [5]. Runoff picks up contaminants that accumulate on impervious surfaces and delivers them to the receiving waterways [6], and increasing development increases contaminant concentrations (e.g., chemicals, bacteria, viruses) [7,8,9,10,11,12]. In areas with no stormwater systems, contaminated runoff flows unfiltered into the water, and in areas with combined sewer systems where the same pipe handles stormwater and sewage, heavy storm events cause overflows which increase the contamination [13]. High runoff events from heavier storms overwhelms the drainage infrastructure in the USA, and this will only become worse with increased urbanization and heavier rains [14]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
