A multimodel ensemble approach to assessment of climate change impacts on the hydrology and water resources of the Colorado River Basin

摘要: Abstract. Implications of 21st century climate change on the hydrology and water resources Colorado River Basin were assessed using a multimodel ensemble approach in which downscaled bias corrected output from 11 General Circulation Models (GCMs) was used to drive macroscale models. Downscaled scenarios (ensembles) as forcings Variable Infiltration Capacity (VIC) model, turn forced Reservoir Model (CRMM). Ensembles precipitation temperature, derived streamflows reservoir system performance through comparison with current simulations for 1950–1999 historical period. For each GCMs, two emissions (IPCC SRES A2 B1, corresponding relatively unconstrained growth emissions, elimination global increases by 2100) represented. Results B1 divided into three periods: 2010–2039, 2040–2069, 2070–2099. The mean temperature averaged over ensembles basin emission scenario ranged 1.2 4.4°C periods 1–3, 1.3 2.7°C. Precipitation changes modest, ranging −1 −2% scenario, +1 −1% scenario. An analysis seasonal patterns showed that most GCMs had modest reductions summer winter precipitation. Derived April 1 snow equivalent declined all members time periods, maximum (ensemble mean) 38% period 3. Runoff mostly result dominance increased evapotranspiration shifts, runoff −1, −6, −11% ensembles, 0, −7, −8% ensembles. These hydrological reflected performance. Average total storage average hydropower production generally declined, however there large range across Releases Glen Canyon Dam Lower reduced both mean. fraction years shortages occurred approximately 20% 3 scenarios.