Climate change impacts on nitrogen and phosphorus loading in New England watersheds

Background and objective: Nitrogen and phosphorus yields in watersheds can be influenced by air temperature and precipitation. Rising air temperature can affect the natural nutrient cycling process since most nutrient cycles are temperature-dependent. It is hypothesized that increasing air temperature and precipitation can alter the hydrologic cycle and impact the yield of both nitrogen and phosphorus in watersheds. This research's primary objective is to evaluate the influence of climate and land use characteristics of the watershed on nutrient loads in New England watersheds.Materials and methods: Nutrient data from the Spatially Referenced Regression on Watershed Attributes (SPARROW) model, land use data came from National Land Cover Database (NLCD), temperature and precipitation from USGS are used in statistical analysis with univariate and robust regression functions. The scatter analysis shows that nitrogen and phosphorus have more variability at higher temperatures.Results and conclusion: Nitrogen and phosphorus have more variation at mid-range precipitation levels and are more diluted with higher precipitation. Robust regression results found that temperature and agricultural land significantly affect nitrogen yields in streams. Temperature, forested land, and agricultural land have the most significant impact on phosphorus in streams. Nutrient management is suggested to target areas to increase watershed resilience to climate change.

Keywords:

land use , Nutrient , Precipitation , temperature , Watershed