Development of Nutrient Model for i-Tree Hydro using Sampling Results from the Mianus River Watershed

Urbanization has created an 'urban biogeochemistry' with accelerated and imbalanced nutrient cycles, polluted waterways, and compromised ecosystems due to poorly coupled interactions between society and the urban environment. Our research group tests nitrogen and phosphorus cycle algorithms in I-Tree Hydro to quantify the changes in water quality and quantity that result from changes in urbanization and land use. This presentation focuses on i-Tree Hydro nitrogen and phosphorus dynamics with changing tree and green infrastructure cover. The model is tested using water chemistry and land cover analyses from the Mianus River watershed, a 91 sq km area in Bedford, New York and Stamford, Connecticut. Storm samples are taken from areas draining a variety of land uses, and are analyzed for all nitrogen species, as well as in-situ denitrification measurements. Emphasis is placed on best management practices and structures and their effectiveness in storm event nutrient removal; comparisons between drainage areas that have green space and those that do not will be analyzed. This research should inform model simulation of how water chemistry is affected by management decisions, and how land can be best managed to promote effective nutrient cycling.