Nutrient Runoff Assessment in Agricultural Lands Using the MIKE SHE Simulation Framework

Abstract

 Accurate assessment of nutrient runoff in farming regions is crucial for managing watersheds and 
preserving water quality. This study uses the MIKE SHE integrated hydrological modeling system to simulate and 
evaluate the nutrient runoff behavior across agricultural watersheds with different land uses and climate conditions. 
The model was calibrated and validated against long-term hydrometeorological and water quality datasets, thus 
assuring its reliability in modeling surface runoff, subsurface flow, and nutrient transport. Historical climate data from 
1980 to 2020, along with land use change, were evaluated for their impacts on nutrient exports using a combination 
of runoff reduction techniques and spatial regression. Findings indicate that intensively fertilized zones are major 
contributors to nitrate and phosphorus loading, especially during the peak rainfall season. Analyses of various 
scenarios show that certain land use changes, such as converting forests and wetlands to farmland, dramatically 
increase nutrient runoff, while some conservation measures, notably the implementation of buffer strips and wetland 
restoration, should reduce hydrological nutrient export. In addition, the results demonstrated that the projected impacts 
of climate change worsen nutrient loss through runoff as a result of intensified precipitation and increased soil 
saturation. 
The MIKE SHE system works well for understanding the interplay of water, nutrients, and biological systems as it 
relates to nutrient pollution. This makes it helpful in evaluating policies and managing programs aimed at agricultural 
watershed nutrient pollution.