| Summary: | The 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.
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