Estimation of Climate Change Impacts on Water Resources in the Great River Watershed, Jamaica

The Great River Watershed, located in north-west Jamaica, is recognized as a critical watershed for development, particularly in the areas of housing, tourism, agriculture, and mining. Additionally, it is a source for sediment and other nutrient loading to the coastal environment. Island states frequently make decisions based on watershed impacts. This requires an in-depth understanding and analysis of factors such as water resources, land use/cover, and climate change impact among others at the watershed level. An integrated modelling framework has been proposed for this watershed that includes modelling of hydrological parameters using the Soil and Water Assessment Tool (SWAT) and projected changes in temperature and rainfall on water resources. The simulated model performance statistics for high flow discharge yielded a Nash-Sutcliffe Efficiency (NSE) value of 0.68 and a coefficient of determination (R-2) value of 0.70 suggesting good measured and simulated (calibrated) discharge correlation. Projected climate change will likely have huge impacts on available water in stream flow. Similarly, the potential impacts to soil water content, evapotranspiration, and surface runoff are also shown to be highly sensitive and important. The calibrated SWAT model can and should be used for further analysis of the effect of climate change as well as other different management scenarios for the remaining 25 watersheds in Jamaica as well as other island states in the Caribbean.