Analysis Of The Relation Between Snow Water Equivalent In The Upper Colorado River Basin And Naturalized Flow In The Colorado River

Abstract

The Colorado River is one of the most important rivers in the world, supplying water to 40 million people in seven states in the United States, and two states in Mexico. However, the river is threatened by impending climate change which may limit the availability of water resources in the basin. The purpose of this analysis was to investigate the relation between average snow water equivalent (SWE) and naturalized flow in the Colorado River. Data were analyzed from the high- resolution University of Arizona SWE product (Dawson et al., 2018) over the Upper Colorado River Basin and compared to naturalized flow in the Colorado River at Lee’s Ferry. A Pearson correlation test was then performed on the five-year moving averages of each dataset to establish the statistical relation between the two continuous variables. The Pearson correlation coefficient was 0.90, which indicates a strong positive correlation between SWE and naturalized flow. Additional correlation tests were performed on the raw (unaveraged) data to further characterize this association and explore the potential for seasonal flow forecasting. SWE data were analyzed when unlagged, and then lagged one to three months. The correlation tests resulted in coefficients of 0.10 when unlagged to 0.80 at three months.