Modeling the impact of climate change on the hydrology of Eagle Mountain Lake, Texas

Abstract

This study investigates the modeling of climate change impacts on streamflow dynamics within the Upper West Fork Trinity Watershed, employing the Soil and Water Assessment Tool (SWAT). The study begins with the successful development and validation of a SWAT model for the historical period (1990-2022), demonstrating strong agreement between simulated and observed streamflow data. Subsequently, the model is utilized to assess the impacts of projected climate change scenarios (2030s and 2080s) under different Shared Socioeconomic Pathways (SSPs) on streamflow dynamics. The findings reveal consistent trends of increasing average temperatures across all scenarios, with temperature projections aligning with global warming patterns observed in various watersheds worldwide. Moreover, projected precipitation patterns indicate both increases and decreases, leading to increased uncertainty and variability in future climatic conditions. These changes in temperature and precipitation translate into significant alterations in streamflow dynamics within the watershed. Despite anticipated increases in average annual precipitation, the model projects a decrease in streamflow, particularly during spring and early summer months, which could impact water availability in the Eagle Mountain Lake reservoir. Specifically, the average annual streamflow in the watershed is projected to decrease by 17% to 20% under future climatic conditions compared to the 2003 – 2022 observed streamflow. However, projections also suggest an increase in streamflow during summer, fall, and winter months by 18%, 12%, and 3.6% respectively, potentially offsetting spring deficiencies in the reservoir but also raising concerns about riverine and lake flooding. Overall, this study provides valuable insights into the potential impacts of climate change on water resources within the Upper West Fork Trinity Watershed, highlighting the importance of adaptive management strategies in mitigating the effects of evolving environmental conditions.