Predicting Climate Change Impacts on Water Balance Components of a Mountainous Watershed in the Northeastern USA

Forcing watershed models with downscaled climate data to quantify future water regime changes can improve confidence in planning. The Soil Water Assessment Tool (SWAT) was calibrated (R2 = 0.77, NSE 0.76, and PBIAS 7.1) validated 0.8, 0.78, 8.8) using observed monthly streamflow a representative mountainous the northeastern United States. Four global (GCMs) under two Representative Concentration Pathways (RCP 4.5, RCP 8.5) were forced. Future periods separated into three 20-year intervals: 2030s (2031–2050), 2050s (2051–2070), 2070s (2071–2099), compared baseline conditions (1980–1999). Ensemble means of four GCMs showed an increasing trend for precipitation highest average increase 6.78% 8.5. Evapotranspiration (ET) had trends over 21st century showing greater increases both RCPs. Both (4.58–10.43%) yield (1.2–7.58%) Seasonal predicted most months spring summer. ET from Spring early Fall. Study results demonstrate potential sensitivity watersheds need ongoing predictive modeling studies advance forward looking mitigation decisions.