Streamflow Response to Potential Changes in Climate Webapp

The Rio Grande is a vital water source for the southwestern States of Colorado, New Mexico, and Texas and for northern Mexico. Because streamflow in the basin is highly altered, disentangling the impacts of climate change and changes in streamflow due to anthropogenic influences such as dams, diversions, and other forms of water use is difficult. Therefore, a model that simulates naturalized flow (defined as streamflow that would occur in the absence of anthropogenic modifications) was developed to determine to what degree changes in streamflow can be attributed to potential changes in future temperature and precipitation without quantifying future changes in anthropogenic influences.

In this study, the calibrated Upper Rio Grande Basin PRMS model (Moeser and others, 2021) was run with projected climate data (Dixon and others, 2020) to produce a set of streamflow projections through the year 2099 that represent potential future changes in Rio Grande streamflow due to changes in climate. The PRMS model was forced with projections of daily precipitation, minimum daily temperature, and maximum daily temperature from 27 datasets for 1981- 2099. These datasets include data generated from three general circulation models (GCM; Table 1) included in the Coupled Model Intercomparison Project phase 5 (CMIP5) suite of models, using three statistical downscaling methods for three RCP scenarios. To arrive at potential climate-induced impacts, simulated streamflow for the model historical period (1981–2015) was subtracted from three simulated future time periods (2022-47,2048-73, 2074-99), and an analysis of changes in [naturalized] streamflow volume and timing was conducted for the Rio Grande and its tributaries.