Stochastic Assessment of Long-Term Impacts of Phosphorus Management Options on Sustainability with and without Climate Change

Abstract

In this study, a combination of two modified versions of the SWAT 2005 model are used to estimate the impact of several best management practices on phosphorus loading to the Cannonsville reservoir in upstate New York as a function of variable weather and climate. The management scenarios in this study include a base case scenario in which management practices are not changed and three other scenarios in which new practices are implemented to reduce the amount of phosphorus applied to the watershed. The long-term impacts of these scenarios are investigated using historical data and stochastically generated weather data that incorporate projected climate change. The projected changed climate data are used to investigate the impact of a changed climate on the nutrient loading and the effectiveness of the three management practices on reducing nutrient loading to the reservoir. The methodology used here can be helpful to other watersheds as well to assess long term response to best management practices or their absence in the face of uncertainty about future weather and climate.