Monitoring geomorphic change and vegetation development on Clark Fork River Delta using Terrestrial LiDAR

Dr. Alexander Fremier, Washington State University (WSU) developed a study design for monitoring erosion rates and seedling establishment before and after the project construction and planting efforts.  Researchers at WSU will monitor geomorphic and vegetation changes on the delta to quantify potential effects of the project.

Purpose: The Clark Fork Delta Restoration Project aims to reduce further erosion on the delta and promote sediment deposition and riparian establishment. Quantifying the rates and locations of geomorphic change over the delta will help us evaluate restoration effectiveness and isolate causes of varying erosion and deposition rates across the delta. To effectively monitor geomorphic change over this large area, we will be employing two forms of terrestrial LiDAR scanning. LiDAR technology allows us to measure centimeter-scale changes in both geomorphic and vegetative change over a field of view (radius) of ~200 meters.

Protocols: Terrestrial Scanning LiDAR (TLS) is a developed technology for measuring the environment rapidly with profound detail. TLS instruments make high resolution distance measurements of the geomorphic and vegetative surface. We will be applying two types of LiDAR sensors to monitor geomorphic and vegetative change, at multiple time intervals.

The first survey will be a temporally extensive study of multiple sites (10-15) at monthly time intervals in 2014 and 2015. This survey is a traditional application of TLS which requires semi-permanent survey locations and periodic surveys. Site selection will be based on restoration designs and sites of potential erosion and/or deposition. Site selection will occur in March 2014.

The second survey will be an intensive study of a few sites (1-3) at approximately daily time intervals over 2-3 months in 2014 and 2015. This will use a new form of LiDAR technology called Autonomously-operating TLS (ATLS, Eitel et al. 2013). This survey method samples the environment continuously over the 2-3 month period to capture highly temporally resolved surfaces to record geomorphic and vegetative change.

Timeline: Site selection and initial surveys will start in March 2014. Sampling will continue until delta inundation. In 2015 the delta will be resurveyed from Jan to delta inundation.