Numerical modeling techniques for density-driven flow in coastal aquifers and its application to West Hawai‘i Area Aquifers in island of Hawai‘i.
Hydrologic datasets are essential for the design of sustainable water supply systems and the prediction or detection of acute threats to drinking water quality or availability. We developed a hydrologic monitoring network consisting of 21 instruments including weather stations, stream gauges, and monitoring well dataloggers on the Island of Tutuila, American Samoa.
Assessment of Groundwater Ages Using Radiocarbon and Chlorofluorocarbons in West Hawai‘i Aquifer Systems
A multi-tracer approach was used to determine the apparent groundwater ages in West Hawai‘i. Radiocarbon chlorofluorocarbons were used to date water over a range of ages. The results can be used to assess aquifer storage and travel times, which are important is understanding the hydrologic system and assessing groundwater sustainability.
The study included developing and implementing a conceptual model for the Keauhou Aquifer site in West Hawai‘i, calibrating the model using available data to their fullest extent to constrain parameters, and applying the model for management through simulating various scenarios aimed at assessing the risk to aquatic resources.
A Participatory and Model Based Approach to Assessing Groundwater Recharge Under Contemporary and Future Climate Scenarios: Tutuila, American Samoa
A water budget approach using the Soil Water-Balance-2 model was applied to Tutuila Island in American Samoa. We also assessed potential future change in recharge by substituting rainfall and temperature projections from dynamically downscaled climate global climate model predictions and possible future land-cover scenarios developed with local stakeholders.
This work presents a collaborative modeling framework developed by participants at the American Samoa Power Authority and at the University of Hawai‘i Water Resources Research Center. The framework includes modular components including collection and analysis of climatic and streamflow data and development of a water budget model and groundwater model.
Ridge to Reef Management Implications for the Development of an Open-Source Dissolved Inorganic Nitrogen Loading Model in American Samoa
We developed a dissolved inorganic nitrogen (DIN) loading model by integrating commonly available datasets within a geospatial modeling framework for Tutuila, American Samoa. The model integrated an open-source water budget model, water sampling results, and publicly available streamflow data to predict watershed-scale DIN loading to the island’s entire coastline.