Abstract
The continued growth of Southwestern cities depends on reliable water export from Rocky Mountain headwaters, which provide ∼85% of Colorado River Basin (CRB) streamflow. Despite being more sensitive to warming temperatures, alpine systems are simplified in the regional-scale models currently in use to plan for future water supply. We used an integrated hydrologic model that couples groundwater and surface water with snow and vegetation processes to examine the effect of topographic simplifications as a result of grid coarsening in a representative CRB headwater basin. High-resolution (100 m) simulations predicted headwater streamflow losses of 16% by 2050 while coarse-resolution (1 km) simulations predict only 12%, suggesting that regional-scale models (coarser than 1 km) likely overestimate future Colorado River Basin water supplies.
Highlights
Water supplies in the Colorado River Basin (CRB) serve ~40 million people, irrigate over 5.5 million acres, and drive turbines for more than 4200 megawatts of electrical generating capacity (US Department of the Interior 2012)
We use a localized, physically-based model that integrates groundwater, surface water, and land surface processes (Maxwell and Miller 2005, Kuffour et al 2020) to compare a suite of projected climate impacts as grid resolution is coarsened from 100 m to 1 km in a representative headwater catchment
We find that high-resolution models predict that 4 ◦C of warming increases headwater evapotranspiration (ET) 10% more than coarse-resolution models, predicting streamflow reductions that are 4% greater than coarse resolution models of the same catchment
Summary
Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. Keywords: integrated modeling, resolution, climate change, headwater hydrology, Colorado river Supplementary material for this article is available online
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
