This grant will support the scope of work outlined below. This research will aid TNC in restoring a rare, headland bypass dune ecosystem. The development of a monitoring protocol and establishment of survey control monuments will allow for continued tracking of the success of the restoration project into the future.
1. Conduct a historical analysis of dune geomorphology and vegetation changes from historical aerial photography. Grantee will quantify changes in plant cover and open sand surface area over time to create baseline scenarios for restoration goals. As possible, reconstruct 3D digital elevation models (DEMs) of the terrain using Structure from Motion (SfM) photogrammetry. This information will inform what types of vegetation, if any, are appropriate for restoration of the dune ecosystem.
2. Assess regional wind climatology and sand drift potential for the Point Conception dunes site. As possible, obtain nearby historic wind and precipitation records or climate re-analysis datasets (NARR, ECMWF) that extend back several decades. These data will be used to produce seasonal wind roses, wind power density (WPD) estimates, and model sand drift potential (RDP, per Fryberger and Dean 1979) for the site. RDP 'drift roses' and WPD estimates are commonly used to model sand flux and examine the transporting regime that maintains and controls dune form. Assess if this regime has changed over recent decades (to the extent that historical records allow) and use this to inform restoration approaches in the dune system.
3. Develop and implement a monitoring protocol for quantifying and assessing the response of the dune system to dynamic restoration (invasive iceplant removal) using UAS-based surveys with a high-resolution (cm-scale) RGB payload and SfM photogrammetry. Establish required survey control monuments (for GNSS base stations) and flight planning approvals/logistics. Assess feasibility and potential locations for installation of onsite monitoring stations including autonomous camera systems and weather/sand transport instruments to record onsite aeolian activity, vegetation phenology, and other weather events.
4. Conduct a baseline UAS survey of the site post-removal of invasive plants. Deliverables will include a cm-scale, georeferenced, digital orthophoto mosaic, a high-resolution DEM, and individual photos of the site. Additional UAS surveys would be flown seasonally to capture and quantify changes in the landscape following restoration.
5. Conduct an initial change analysis of dune morphodynamics, sediment budgets, and vegetation cover changes from a second UAS flight.