Future Colorado River Basin Drought and Surplus

Historical and future drought surplus periods in the Colorado River basin are evaluated based on eight climate scenarios. Unimpaired streamflow from 17 stations U.S. Geological Survey, Bureau of Reclamation, Coupled Modeled Intercomparison Projection 5 downscaled data 1950–2099. Representative Concentration Pathway (RCP) 4.5 8.5 emission scenarios considered for four models (HadGEM2-ES, CNRM-CM5, CanESM2, MI-ROC5). Drought (surplus) quantities, magnitudes, severities, water year flows compared historical periods. Results indicate that there is a significant difference between record projections. The results not consistent terms increase or surplus; however, intensity (as measured by magnitude duration) will likely both RCP 8.5. CanESM2 CNRM-CM5 project wetter scenarios, HadGEM2 MI-ROC5 drier For critical Lees Ferry station, chance higher length order two times period. In addition, wide flow at had shift mean ensemble approximately 3–10% year. Future hydrologic changes heighten need appropriate management infrastructure options available to adapt these changes.