Nutrient and Sediment Modeling in Watersheds Across an Urban-Rural Gradient

Katherine Weber
Jim Saiers
Start Date: 
May, 2015

The movement of nitrogen, phosphorus, and suspended sediments within a watershed affects the efficiency of water treatment, the effectiveness of restoration activities on water quality, and the composition of life within the river. In this study, I will model nutrient and sediment loading in three watersheds within the larger Connecticut River watershed. In order to compare these three watersheds, I will use two different models (InVEST and a variant of SWAT), which will each provide predictions of sediment and nutrient loading (i.e. kg/year) in the rivers as well as where those sediments and nutrients are coming from (in the form of a map).

I can then compare the models’ predictions to observed data from the multi-probes installed in the rivers (concentration and flow data), supplemented by water samples I take by hand. This will allow me to see which of the two models is more accurately describing the amount of sediment, nitrogen, and phosphorus in each of the three rivers. As there will be samples from multiple points along the rivers, I will also be able to tell how well the models are predicting where the sediment and nutrients are coming from. Finally, the more accurate of the two models will be coupled with an optimization model (RIOS) that incorporates the cost of purchasing land and the value of sediment or nutrient removal by the watershed. The results of this project will highlight the locations within the watershed that are critical for sediment and nutrient retention and water supply protection.

There will be remotely sensed data collected within the study watersheds mentioned above (LiDAR and thermal data and potentially hyperspectral images as well).  I plan to analyze this data with the software available in the YCEO lab.