Evaluating climate change impacts on water quantity and quality of the upstream Everglades system

摘要

The drainage basin of Lake Okeechobee serves as the source areas of water and nutrients to downstream waterbodies and ecosystems such as the Everglades. The loadings are sometimes excessive, causing water drainage and quality issues. Areas and sourcesthat disproportionally produce runoff and pollutants within the basin have not been known in detail enough to guide local management planning to the implementation of targeted measures. In addition, changing climate presents a further challenge to waterresources management. This study identified critical source areas and types of two study watersheds draining water and nutrient to Lake Okeechobee and then evaluated the potential impacts of projected climate changes on water and nutrient loading from the identified sources. Two watershed loading models, Watershed Assessment Model (WAM) and Soil and Water Assessment Tool (SWAT), which are commonly employed as a tool for watershed assessment in Florida and U.S. respectively, were prepared to quantify the loadings. Ensemble future climate projections were prepared for each of weather stations associated with the watershed from multiple climate models that the most closely reproduced the characteristics of historical rainfall events. Results showed that(I) locations, types, and loads of critical sources, (2) climate change impacts on the nutrient loadings, and (3) performance of WAM and SWAT. This study provides a picture of how global-scale changes can affect local watershed processes and helps to develop effective climate change adaptation plans to improve the sustainability of Everglades 'agricultural and natural resources.