Toward Improved Seasonal Forecasting of Water Resources and North American monsoon Precipitation in the Southwestern United States

Current and future discharge major river basins such as Colorado Rivers is an increasing concern for water management in the United States and Mexico.  Population growth and residential construction have increased water demand and wastewater discharge in the major watershed in recent years. These human activities, coupled with climate variability and change can significantly influence the hydroclimate. Though there is evidence that climate change is presently occurring from the recent observational record on global and continental scales, how these changes ultimately bear on the hydroclimate at the localized scale of a relatively small river basin is still highly uncertain. Observed streamflow declines in the Colorado Basin in recent years are likely due to synergistic combination of anthropogenic global warming and natural climate variability, which are creating an overall warmer and more extreme climate.   More reliable projection of basin streamflow, that takes into account these dual effects, is urgently needed for long-term water resource planning.  

We designed an integrated physical modeling approach to evaluate the impact of climate change in the Colorado River basin and its hydrology, incorporating a very high spatial resolution atmospheric model (on the kilometer scale) and assess the climate impact on hydrologic modeling. Our main objective is to characterize how North American monsoon-related convective precipitation can be improved in the Southwest and the corresponding response of Colorado River basin streamflow.   This research aims to address two principal research questions: (1) what is the impact of the atmospheric model resolution and better physical representation of precipitation processes on the characterization of the mean climate and extremes?  and (2) what is the impact when high resolution climate model information is used to drive hydrologic modeling for Southwest U.S. and Mexico?