Detecting Eutrophication Sources, Hotspots, and Nutrient Levels in a Central California Estuary to Support Watershed Management Decisions

Elkhorn Slough in Monterey, California has experienced substantial nutrient loading and eutrophication over the past 21 years as a result of fertilizer-rich runoff from nearby agricultural fields. This study seeks to identify and track spatial patterns of eutrophication hotspots and the correlation to land use changes, possible nutrient sources, and general climatic trends using remotely sensed and in situ data. Threats of rising sea level, subsiding marshes, and increased eutrophication hotspots demonstrate the necessity to analyze the effects of increasing nutrient loads, relative sea level changes, and sedimentation within Elkhorn Slough. The Soil & Water Assessment Tool (SWAT) model integrated specified inputs to assess nutrient and sediment loading and their sources. TerrSet's Land Change Modeler forecasted the future potential of land change transitions for various land cover classes around the slough as a result of nutrient loading, eutrophication, and increased sedimentation. TerrSet's Earth Trends Modeler provided a comprehensive analysis of image time series to rapidly assess long term eutrophication trends and detect spatial patterns of known hotspots. Results from this study will inform future coastal management structures and provide greater spatial and temporal insight into Elkhorn Slough eutrophication dynamics

Location

NASA Ames Research Center

Term

Summer 2016

Partner(s)

Elkhorn Slough National Estuarine Research Reserve (ESNERR)
Monterey Bay Aquarium Research Institute

NASA Earth Observations

Landsat 5, TM
Landsat 7, ETM+
Landsat 8, OLI

Team

Martha Sayre (Project Lead)
Irma Caraballo Álvarez
Abigail Childs
Kirsten Jurich

Advisor(s)

Dr. Juan Torres-Pérez (Bay Area Environmental Research Institute)
Dr. Sherry Palacios (Bay Area Environmental Research Institute)

Project Video