Stefan Talke, Senior Research Associate in the Department of Civil and Environmental Engineering, has been selected for the prestigious Young Investigator Program (YIP) at the Office of Naval Research (ONR). The YIP provides support to early-career academic scientists or engineers who show exceptional promise for conducting creative research.
Dr. Talke’s proposal, "Improving Estuarine Transport Models using Satellite Measurements,” was one of 26 proposals accepted by the ONR out of a pool of over 350 applicants. His new research will combine satellite measurements, field observations, and numerical models to better understand salinity intrusion and sediment transport in estuaries. Specifically, the project seeks to answer the following questions:
• Do satellite data agree with our established understanding of how salinity and turbidity (‘muddiness’) vary in estuaries under different river flow and tidal conditions?
• Can satellite measurements be used to calibrate numerical models as a function of river flow and tidal forcing?
• For poorly gauged estuaries, can idealized models be combined with satellite measurements to assess basic system properties (e.g., mixing, river flow, depth)?
The new research will investigate satellite data and parameter estimation methods in four estuaries: the Columbia River Estuary, the Duwamish Estuary (Seattle), the Ems-Dollard estuary (Germany), and the sparsely gauged Mekong Delta in Vietnam. Data from the National Oceanic and Atmospheric Administration’s Terra/Aqua and Landsat satellites will be mined to create a ‘climatology’ of sediment distribution and salinity for different tidal and river flow conditions. Results will be calibrated by and compared with existing monitoring data. Additionally, several field experiments in the Columbia River and the Duwamish River are planned. A numerical model (Delft3D) will be used to simulate physical conditions under different river flow/tidal scenarios. Methods of calibrating the model using satellite data, and of reverse engineering system properties using the satellite data, will be explored.
The project will result in an improved understanding of satellite measurements and their use for calibrating/validating models and obtaining system parameters. Our present understanding of estuary transport is limited by a lack of spatial resolution in field measurements. Because the spatial distribution of salinity and sediment trapping/erosion has ecological, water quality, and engineering implications, the use of satellite data may help us improve our understanding of this valuable environment.