Streamflow High Spells Analysis to Evaluate Flood Risks and Severity
Abstract
Understanding hydrological processes within urban watersheds are increasingly important in part due to the increased risk and severity of flood events due to climate change. This study examines how increased urbanization affects the largest flood event of the last 50 yr within the Pawtuxet River watershed, Rhode Island, USA. The 2010 flood resulted in a major disaster declaration and a preliminary individual assistance cost of more than three million dollars with approximately 40% of these damages to low-income housing. To inform management and reduce flood risk, we first must evaluate the factors driving the hydrology of the Pawtuxet River watershed. We used the SWAT model to assess how LULC changes affect flood events. This study has four objectives: (1) use peak flow estimates for the Pawtuxet River to model the 2010 flood, (2) model the watershed with multiple scenarios of increased urbanization, (3) determine the impact of increased urban land cover on the Pawtuxet River watershed, and (4) determine if LULC or management drives flood events in the watershed. The calibrated model had a Nash-Sutcliffe efficiency (NSE) of 0.69. The validation had an NSE of 0.65. We conducted a high spell analysis for the streamflow output from 2010 to 2013. The average high spell volume in 2010 was nearly double all other years. The scenarios with increased urban land use saw an increase in the mean volume of high spells; however, there was not an increase in the 2010 floods peak.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2020
- Bibcode:
- 2020AGUFMGC0840005P
- Keywords:
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- 1622 Earth system modeling;
- GLOBAL CHANGE;
- 1637 Regional climate change;
- GLOBAL CHANGE;
- 4313 Extreme events;
- NATURAL HAZARDS;
- 4325 Megacities and urban environment;
- NATURAL HAZARDS