The future of the Salton Sea under proposed lower Colorado River basin water management scenarios

dc.contributorGrant, William E.
dc.creatorKjelland, Michael Edward
dc.description.abstractThe Salton Sea, situated in the Lower Colorado River Basin (LCRB), is under duress due to, among other things, increased water demands of cities like San Diego, California and Mexicali, Mexico. This research developed a tool to investigate the implications of water transfers on the health and sustainability of the Salton Sea Ecosystem. The Salton Sea model is a spatially-explicit, stochastic, simulation model representing water flow, i.e., water volume and quantity of Total Dissolved Salts (TDS) and Phosphorus (P), in the LCRB as it enters the Salton Sea. The model is formulated as a compartment model based on difference equations with a daily time step using STELLA? 8.0 software. The model was developed, evaluated, and applied to simulate the potential effects on the population dynamics of selected fish and avian species at the Salton Sea under six different scenarios. Oneway ANOVAs and Bonferroni Multiple Comparison Post Hoc Tests were performed for the water management scenarios and selected variables involving the fish and bird population dynamics using SPSS version 12.0.1 (SPSS Inc., 2003). Weather station daily data were collected for both precipitation and Eto for a 25- year period (1980-2004) for the Salton Sea area. Thirty-four probability distributions were fit to the monthly datasets. Monthly distributions were used to preserve seasonality when modeling future climate scenarios. Additionally, binomial and multinomial logistic regression models were utilized to determine the relationships concerning precipitation events and Eto levels. Further, two strategies were employed in modeling the uncertainty in future climate patterns, namely deterministic and stochastic versions of the driving variables. A climate sensitivity analysis was also conducted and results showed that the cumulative effects and change of plus or minus 10 percent in Salton Sea inflows can have significant effects on sea elevation and salinity. Both of the Salton Sea impoundment scenarios significantly (P<0.05) lowered the salinity in the north or main sea impoundments compared to future downward trends in sea elevation and upward trends in salinity under baseline conditions. Further, the elevations of the north or main sea impoundments were stabilized at -220 by the end of 2024. Should action be taken to stabilize the sea and reduce salinity, the impoundment scenarios demonstrated the most success in the present study. If no such action is taken, the simulation results demonstrate that the current community dynamics of the Salton Sea will be further impaired as a result.
dc.subjectSalton Sea
dc.titleThe future of the Salton Sea under proposed lower Colorado River basin water management scenarios