How Might Historical Record Droughts in Texas Evolve and Impact Water Resources in a Warming Future?
The Colorado River Basin (CRB) in Texas underwent a prolonged dry spell from 2008 to 2015, with record meteorological drought in 2011 coinciding with record summer heatwaves producing severe impacts to agriculture, surface water resources, and the environment. Climate warming is projected to intensify extreme drought and compound dry-hot conditions, underscoring the need for water resource management strategies to consider these risks. In this research, we assess how the record drought in the CRB may evolve over time and space under a warming future, from the perspectives of meteorology, agriculture, and hydrology, as well as their propagation characteristics. Climate data from 2008 to 2015 used in the study were downscaled from the WRF (Weather Research and Forecasting) model, and climate projections for the near future (2048-2055) and far future (2088-2095) segments were developed using a thermodynamic global warming approach (TGW) representing a range of warming scenarios informed by Global Climate Models (GCMs) under different Representative Concentration Pathways (RCPs). A high-resolution, spatially distributed hydrological model, the Distributed Hydrology Soil Vegetation Model (DHSVM) was developed to simulate hydrological processes in the CRB, thereby replicating historical streamflow conditions and projecting hydrological impacts under future states. This study also evaluates the characteristics of future compound hot and dry events, recognizing their amplified impact on water resources compared to isolated drought events.