A REVIEW OF THE USE OF THE SOIL AND WATER ASSESSMENT TOOL (SWAT) TO MODEL NUTRIENT LOADING IN THE FACE OF CLIMATE CHANGE

Abstract

As global climate patterns continue to evolve, the complex relation between land use, hydrology, and nutrient dynamics in watersheds becomes increasingly complex. The Soil and Water Assessment Tool (SWAT) has emerged as a robust tool for simulating the impacts of land management practices, climate variability, and changing environmental conditions on water resources. This thesis offers a comprehensive literature review of the application of SWAT in modeling nutrient loading, with a particular focus on addressing the challenges posed by climate change. It provides an insights into the strengths and limitations of SWAT, shedding light on its ability to capture the intricate relationships between climate, land use, and nutrient cycling. The review encompassed examining recent advancements and methodologies employed in utilizing SWAT to assess nutrient dynamics within diverse landscapes. Special attention was given to the tool's ability to predict nutrient transport, transformations, and loading under various climate change. The results of this work revealed weaknesses in the model’s ability to simulate nutrient transport in cold and mountainous regions. Moreover, it revealed a skew in the geographical extent where the model has been applied. Integration of future climate data projections was found to vary significantly between studies in terms of the spatio-temporal scale, GCM models adopted, and the use of ensemble estimates. This work helps policymakers identify the existing limitations of SWAT, while proposing future developments needed to improve its use as an effective predictive tool for assessing future water quality impairments in the face of a changing climate.