Type of Presentation

Oral

Session Title

Long term studies reveal the complex dynamics and interconnectivity of the physical, geomorphic, biological systems of Salish Sea shorelines and how these systems interact with social and political systems

Description

Analysis of four boat-based lidar surveys performed by the Washington State Department of Ecology, Coastal Monitoring & Analysis Program between 2012 and 2015 along the Dungeness bluffs provided new insights to chronic and event-based mechanisms and processes of bluff erosion. We obtained sub-meter resolution data at very high density along the bluffs, which is much more robust than previous airborne lidar datasets due to the horizontal look-angle from the boat. We verified the feasibility of both classifying features in the lidar point cloud, such as vegetation, talus deposits, LWD, and shoreline armoring, and extracting associated quantities to better characterize their relationship to bluff sediment supply.

While land-use planners and coastal managers are in need of long-term erosion rates for prudent resource management, property owners experience localized erosion and tend to be most interested and concerned about the magnitude of bluff recession occurring along relatively small increments of space along their bluff-top property boundary. Thus, a key advantage of boat-based lidar data is the ability to deliver high-resolution spatially explicit topographic relief and quantitative analysis of beach and bluff erosion over relevant time scales to inform highly localized, parcel-by-parcel decision-making. This ability enables property owners and coastal managers alike to take a more refined approach in assessing erosion as well as their options for addressing its causes. For example, repeat surveys performed at relatively short intervals enable a better determination of the relative importance of a variety of mechanisms contributing to bluff erosion such as surface runoff and associated land clearing and development practices, wind, precipitation, groundwater discharge, soil saturation, and hydrodynamic processes. This information is key for landowner assessment and decision-making for increasing their resilience and compatibility with residing along the shoreline.

This document is currently not available here.

Share

COinS
 

Increasing coastal resiliency of bluff-top development through high-resolution imagery and information

2016SSEC

Analysis of four boat-based lidar surveys performed by the Washington State Department of Ecology, Coastal Monitoring & Analysis Program between 2012 and 2015 along the Dungeness bluffs provided new insights to chronic and event-based mechanisms and processes of bluff erosion. We obtained sub-meter resolution data at very high density along the bluffs, which is much more robust than previous airborne lidar datasets due to the horizontal look-angle from the boat. We verified the feasibility of both classifying features in the lidar point cloud, such as vegetation, talus deposits, LWD, and shoreline armoring, and extracting associated quantities to better characterize their relationship to bluff sediment supply.

While land-use planners and coastal managers are in need of long-term erosion rates for prudent resource management, property owners experience localized erosion and tend to be most interested and concerned about the magnitude of bluff recession occurring along relatively small increments of space along their bluff-top property boundary. Thus, a key advantage of boat-based lidar data is the ability to deliver high-resolution spatially explicit topographic relief and quantitative analysis of beach and bluff erosion over relevant time scales to inform highly localized, parcel-by-parcel decision-making. This ability enables property owners and coastal managers alike to take a more refined approach in assessing erosion as well as their options for addressing its causes. For example, repeat surveys performed at relatively short intervals enable a better determination of the relative importance of a variety of mechanisms contributing to bluff erosion such as surface runoff and associated land clearing and development practices, wind, precipitation, groundwater discharge, soil saturation, and hydrodynamic processes. This information is key for landowner assessment and decision-making for increasing their resilience and compatibility with residing along the shoreline.