Baseline mapping of beaches and bluffs with boat-based lidar
Presentation Abstract
In 2015, the Washington State Department of Ecology Coastal Monitoring & Analysis Program (CMAP) collected high-resolution baseline beach and bluff topographic data using boat-based lidar along nearly two dozen drift cells spanning >200 km of Puget Sound shoreline. The lidar data was complemented by the concurrent collection of shoreline photographs, ground-based GPS surveys, and beach sediment grain-size. The drift cells were selected based on a rigorous and systematic geospatial analysis of bluff-backed beaches for their potential for significant bluff sediment supply to intact shorelines identified as having a relative abundance of habitat for forage fish, eelgrass, herring, shellfish, and geoduck, as well as having previous investments in beach restoration projects. As such, the surveyed drift cells are top candidates for implementing drift cell-scale protection and restoration strategies. The data set provides the opportunity to inventory and characterize the shoreline landscape that affects nearshore ecosystem services such as feeder bluff activity, beach slope and width, the position, length, and elevation of armoring relative to the backshore, and quantities of large woody debris and overhanging riparian vegetation. Compared to airborne lidar, boat-based lidar provides a more advantageous point of view of the bluff face, resulting in much higher resolution data which is needed to gain insight into bluff failure and erosion mechanisms and corresponding sediment transport processes. In addition, the near-horizontal look angle of the laser enables high density data of vertically oriented features such as bluffs and shoreline armoring, and successfully collects data under overhanging vegetation and overwater structures. Repeat surveys in the future would enable change analyses for quantifying bluff sediment supply, changes in marine riparian vegetation, and a better understanding of the linkages between physical and ecological processes.
Session Title
Mapping and Data
Conference Track
Salish Sea Snapshots
Conference Name
Salish Sea Ecosystem Conference (2016 : Vancouver, B.C.)
Document Type
Event
Location
2016SSEC
Type of Presentation
Snapshot
Genre/Form
presentations (communicative events)
Contributing Repository
Digital content made available by University Archives, Heritage Resources, Western Libraries, Western Washington University.
Subjects – Topical (LCSH)
Coastal mapping--Salish Sea (B.C. and Wash.); Beach ridges--Salish Sea (B.C. and Wash.); Coastal ecosystem health--Salish Sea (B.C. and Wash.); Ecological surveys--Salish Sea (B.C. and Wash.)
Subjects – Names (LCNAF)
Washington (State). Department of Ecology
Geographic Coverage
Salish Sea (B.C. and Wash.)
Rights
This resource is displayed for educational purposes only and may be subject to U.S. and international copyright laws. For more information about rights or obtaining copies of this resource, please contact University Archives, Heritage Resources, Western Libraries, Western Washington University, Bellingham, WA 98225-9103, USA (360-650-7534; heritage.resources@wwu.edu) and refer to the collection name and identifier. Any materials cited must be attributed to the Salish Sea Ecosystem Conference Records, University Archives, Heritage Resources, Western Libraries, Western Washington University.
Type
Text
Language
English
Format
application/pdf
Baseline mapping of beaches and bluffs with boat-based lidar
2016SSEC
In 2015, the Washington State Department of Ecology Coastal Monitoring & Analysis Program (CMAP) collected high-resolution baseline beach and bluff topographic data using boat-based lidar along nearly two dozen drift cells spanning >200 km of Puget Sound shoreline. The lidar data was complemented by the concurrent collection of shoreline photographs, ground-based GPS surveys, and beach sediment grain-size. The drift cells were selected based on a rigorous and systematic geospatial analysis of bluff-backed beaches for their potential for significant bluff sediment supply to intact shorelines identified as having a relative abundance of habitat for forage fish, eelgrass, herring, shellfish, and geoduck, as well as having previous investments in beach restoration projects. As such, the surveyed drift cells are top candidates for implementing drift cell-scale protection and restoration strategies. The data set provides the opportunity to inventory and characterize the shoreline landscape that affects nearshore ecosystem services such as feeder bluff activity, beach slope and width, the position, length, and elevation of armoring relative to the backshore, and quantities of large woody debris and overhanging riparian vegetation. Compared to airborne lidar, boat-based lidar provides a more advantageous point of view of the bluff face, resulting in much higher resolution data which is needed to gain insight into bluff failure and erosion mechanisms and corresponding sediment transport processes. In addition, the near-horizontal look angle of the laser enables high density data of vertically oriented features such as bluffs and shoreline armoring, and successfully collects data under overhanging vegetation and overwater structures. Repeat surveys in the future would enable change analyses for quantifying bluff sediment supply, changes in marine riparian vegetation, and a better understanding of the linkages between physical and ecological processes.
