Major Goals and Objectives

The primary objective of this study is to establish a high-resolution, spatially explicit understanding of total nitrogen (TN) and total phosphorus (TP) export across the Lake Michigan Basin, spanning the period from 2001 to 2020. By calibrating and integrating advanced modeling techniques, the Weighted Regression on Discharge, Time, and Season with Kalman filtering (WRTDS-K) method and the Spatially Referenced Regressions On Watershed attributes (SPARROW) model, this work seeks to (1) quantify spatiotemporal trends in TN and TP loading and identify localized hotspots of nutrient export, and (2) disentangle the relative contributions of human activities (e.g., fertilizer application, wastewater management, conservation practices) and hydrological variability (e.g. precipitation, temperature). Ultimately, these objectives aim to support policymakers, stakeholders, and local communities in developing more effective nutrient management plans and ensuring the sustainability of vital freshwater resources in and around the Lake Michigan Basin.