Description: A new article from our Los Alamos research team explores the complex interaction between climate and change topography and how this impacts the Colorado River.
Abstract: The Colorado River basin (CRB) is one of the most important watersheds for energy, water, and food security in the United States. CRB water supports 15% of U.S. food production, more than 50 GW of electricity capacity, and one of the fastest growing populations in the United States. Energy–water–food nexus impacts from climate change are projected to increase in the CRB. These include a higher incidence of extreme events, widespread snow-to-rain regime shifts, and a higher frequency and magnitude of climate-driven disturbances. Here, we empirically show how the historical annual streamflow maximum and hydrograph centroid timing relate to temperature, precipitation, and snow. In addition, we show how these hydroclimatic relationships vary with elevation and how the elevation dependence has changed over this historical observational record. We find temperature and precipitation have a relatively weak relation to interannual variations in streamflow timing and extremes at low elevations, but a relatively strong relation at high elevations where more snow occurs in the CRB. Based on these findings, we hypothesize where warming and precipitation-related streamflow changes are likely to be most severe using a watershed-scale vulnerability map to prioritize areas for further research and to inform energy, water, and food resource management in the CRB.
Reference: Solander, K.C., Bennett, K.E., Fleming, S.W., Gutzler, D.S., Hopkins, E.M., Middleton, R.S. (2018). Interactions between Climate Change and Complex Topography Drive Observed Streamflow Changes in the Colorado River Basin, Journal of Hydrometeorology 19, 1637–1650 (https://journals.ametsoc.org/doi/abs/10.1175/JHM-D-18-0012.1).