Identifying stream temperature variation by coupling meteorological, hydrological, and water temperature models
Citation:
Tang, C. AND V. Garcia. Identifying stream temperature variation by coupling meteorological, hydrological, and water temperature models. JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION. American Water Resources Association, Middleburg, VA, 59(4):665-680, (2023). https://doi.org/10.1111/1752-1688.13113
Impact/Purpose:
The linkage provides a generally accurate, well-tested tool for evaluating water temperature changes in the MRB. The following work on the impacts of water temperature on nutrient loads may be broadly applicable across other large river basins and could potentially be used as a “rule of thumb” for nutrient management. This work will also inform the Environmental Protection Agency’s (EPA) Gulf Hypoxia task force, and is broadly applicable to water management, nutrient load investigation, power plant production, and the protection of natural ecosystems.
Description:
In this study, we demonstrate a physically based semi-Lagrangian water temperature model known as the River Basin Model (RBM) coupled with the Variable Infiltration Capacity (VIC) hydrological model and Weather Research & Forecasting Model in the Mississippi River Basin (MRB). The results of this coupling compare favorably with observed water temperature data available from six river gages located in the MRB. Further sensitivity analysis indicates that the mean water temperatures may increase by 1.3, 1.5, and 1.8°C in northern, central, and southern MRB zones under a hypothetical uniform air temperature increase of 3.0°C. If air temperatures increase uniformly by 6.0°C in this scenario, then water temperatures are projected to increase by 3.3, 3.5, and 4.0°C. Lastly, downscaled air temperatures from a global climate model are used to drive the coupled VIC and RBM model from 2020 to 2099. Average stream temperatures from 2020 to 2099 increase by 1.0 to 8.0°C above 1950 to 2010 average water temperatures, with non-uniform increases along the river. In some portions of the MRB, stream temperatures could increase above survival thresholds for several native fish species, which are critical components of the stream ecosystem. In addition, increased water temperatures interact with nutrient loadings from sources throughout the MRB, which is expected to exacerbate harmful algal blooms and dead zones in the Gulf of Mexico.
URLs/Downloads:
DOI: Identifying stream temperature variation by coupling meteorological, hydrological, and water temperature models