Graduation Date

Fall 2017

Document Type



Master of Science degree with a major in Environmental Systems, option Geology

Committee Chair Name

Melanie Michalak

Committee Chair Affiliation

HSU Faculty or Staff

Second Committee Member Name

Geoff Hales

Second Committee Member Affiliation

Community Member or Outside Professional

Third Committee Member Name

Jasper Oshun

Third Committee Member Affiliation

HSU Faculty or Staff

Fourth Committee Member Name

Tom Lisle

Fourth Committee Member Affiliation

Community Member or Outside Professional

Subject Categories



Application of agisoft photoscan and sediment transport modeling for the analysis of sediment wave propagation succeeding gravel augmentation, oak grove fork of the clackamas river, oregon

Mindi Lea Curran

Physical features in alluvial rivers such as riffles, gravel bars, pools, and side channels provide refugia, nutrients, and spawning and rearing habitat for anadromous fish and other aquatic organisms. The downstream transport of gravels that continuously replenish these features is prevented by dams, and often leads to a coarsened channel bed condition and other geomorphic changes that have negative impacts on aquatic organisms. Geomorphic change in rivers can be challenging to capture in high resolution, making the propagation and distribution of sediment difficult to quantify, especially if the deposition occurs in small quantities or thin layers. One solution for replenishing physical features that have been cut off from gravel supply downstream of dams is gravel augmentation. This thesis uses two independent methods to investigate the transport and storage of augmented gravels as they route downstream: 1) topographic change detection using photogrammetry and differencing of Digital Terrain Models (DTMs), and 2) a 1D sediment transport model created in HEC-RAS (Hydrologic Engineering Centers River Analysis System) to model flow and sediment scenarios. Together, these methods are used to investigate sediment wave propagation and channel response to augmented gravels. The location of study is the Oak Grove Fork (OGF), one of the largest tributaries of the Clackamas River, located in northwestern Oregon. The Lake Harriet Dam and diversion were built on the OGF in 1924 as part of a hydroelectric development project by Portland General Electric. Decreased flow and sediment supply downstream of Lake Harriet Dam has resulted in geomorphic and biological changes (including reduced salmonid habitat), leading to a mandated gravel augmentation program that began in September of 2016, which introduced 250 tons of gravel into the river. High resolution DTMs, generated using photogrammetry, captured topographic change at sites on the order of tenths of feet, with vertical accuracy also on the order of tenths of feet. All change detected at photogrammetry sites within one year of augmentation was determined to be a record of typical, natural year-to-year change and is not attributed to transport and deposition of augmented gravels. The 1D sediment transport model suggests that peak flows, exceeding 1,200 cfs, are the primary driving factors of sediment transport, and that higher peak flows exceeding those seen in 2016 and 2017 will be required to transport the augmented gravels downstream 0.81 miles, past a naturally occurring fish barrier waterfall to where anadromous fish habitat begins. A storage capacity estimate calculation suggests that up to 600 tons of gravel could fill interstitial spaces between existing boulders and cobbles as gravel routes downstream, past Barrier Falls, and into accessible habitat.

Citation Style


Included in

Geomorphology Commons


Thesis/Project Location