A Comparative Analysis of Hydrologic Response to Climate Change in Developed and Undeveloped Watersheds on the New Jersey Coastal Plain

Abstract:

Climate change is projected to have an impact on precipitation patterns across the Mid-Atlantic with the likelihood of an increase in the frequency and magnitude of extreme precipitation events. A greater proportion of total annual precipitation could fall in larger events with the potential to impact flooding, storm water infrastructure, and water supply. The watersheds of the coastal plain of New Jersey draining to the Atlantic and Delaware Bay have mild slopes are underlain by very sandy soils. These areas serve as sources of recharge to the Kirkwood-Cohansey aquifer, which is an important water supply for the region. The Precipitation-Runoff Modeling System (PRMS) was used to simulate the potential impacts of climate change on stream flow and groundwater recharge in two watersheds located within the New Jersey coastal plain. The Batsto River watershed includes parts of the Pinelands Reserve with relatively little development in some its headwater areas, primarily small towns and agricultural land use. The Maurice River watershed includes several urbanized areas along with some agricultural land, but population is expecting to increase within the next 10-20 years. The Maurice River basin is outside the Pinelands Reserve but has significant area that contains Pine Barrens. Models were calibrated using observed stream flow from USGS gages and gridded meteorological data from 1995-2002 and validated with observed data from 2002-2005. The calibrated models were forced using an ensemble of three bias-corrected downscaled climate projections (CMIP5, NOAA NCEP, and ECHAM) to assess and compare the potential response of these two watersheds. All meteorological data were obtained online from the GeoData Portal. Preliminary results indicate that climate change is likely to have a greater impact on stream flow in the developed Maurice River basin than in the undeveloped Batsto River basin. More detailed analyses of stream flow and the potential impacts on groundwater recharge are ongoing. These models will serve as the basis of further research that will examine the potential impacts of land-use change and climate change on stream flow, stream temperature, and groundwater recharge.