EAPSI: Understanding the impacts of agricultural and urban land use on flood prediction and mitigation

Grogan Danielle S, Durham NH

Investigators

Abstract

Flood prediction and mitigation are important aspects of watershed management, especially in New England where a 30-year upward trend in floods has been attributed to a combination of urbanization and climate change. In addition to urban development, New England is currently experiencing an increase in agricultural land development. While increases in flood risk from conversion of forests to urban land has been well studied, conversion from forest to agriculture requires further research. This project will investigate the impact that land use change from forest to agriculture has on flood risks in New England, and will separate impacts due to land use change alone, and impacts of combined land use and climate change. This research will be conducted in collaboration with Dr. Taikan Oki at the University of Tokyo in Japan. Dr. Oki's lab has developed and validated a flood model that is cutting edge in the field of flood and land-use change research. Compared to forests, agricultural land has less capacity to store water in soil and biomass. The seasonal cycle of water consumption through plant evapotranspiration also differs in agricultural land, with potentially greater water consumption than forests during peak growth periods, but significantly less water consumption during dormant and fallow seasons. Most watersheds contain multiple land use types. Therefore hydrologic watershed modeling can help understand these processes and make predictions about future changes in flood risk due to different development patterns. This study will couple two existing models; the first is a water balance model that represents the land surface and water management through dams, irrigation, and interbasin water transfers. The second is a flood model that predicts flood events, flood water volume, and inundation levels. Each of these models alone could not address the research goals outlined here; coupling the models is therefore a unique solution to understanding and predicting the connections between land use change and flood risks. This NSF EAPSI award is funded in collaboration with the Japan Society for the Promotion of Science.