Impacts of climate and land use change on future water resources in the Yadkin River Basin, North Carolina

Abstract:

Rapid changes in climate and socio-economic systems are affecting hydrologic processes and fresh water availability. In particular, temperatures, population growth and urban development are all expected to increase in the Southern United States over the next 50 years, which will further stress regional water resources. With improved knowledge of the interactions among land use-land cover (LULC), climate change, and hydrologic processes, decision makers and natural resource managers can explore opportunities to increase the resilience of water resources to future changes. To address this need, we investigated the impacts of climate and LULC changes on water resources throughout the Yadkin River watershed in North Carolina. From forested headwaters in the Blue Ridge Mountains, the Yadkin River flows through agricultural areas and regions of expanding urbanization in the Piedmont. We selected small watersheds representative of each region for detailed analyses, including changes in LULC, climate, and stream flow. We found no significant trends in water yield, precipitation, or evapotranspiration in representative watersheds dominated by forest, agriculture, or medium intensity development using historic climate and USGS stream gauge data. This suggests that precipitation and LULC have been relatively stable throughout the Yadkin watershed over the last two to three decades. However, our approach melding the National Land Cover Data and U.S. Forest Service Forest Inventory and Analysis Plots indicate that the watershed will experience rapid and substantial changes in land use over the next 50 years, particularly as forest is replaced by urban development. Preliminary analyses with a distributed ecohydroloic model (RHESSys), suggest water yield is sensitive to LULC even without climate change. We will present results that quantify the impact of these changes on hydrologic processes by applying projections of future climate (9 scenarios) and multiple realizations of LULC change projections using RHESSys.