Application of Photogrammetry and Structure from Motion

Techniques for the Analysis of Sediment Wave Propagation

after Dam Removal

Mindi Curran

Humboldt State University-mlc183@humboldt.edu

National Science Foundation Mock Proposal

Dynamics of Coupled Natural and Human Systems Grant

INTRODUCTION:

Dams are one of many human systems that use natural systems for the production of

energy used to fuel societal needs. It is of the upmost importance that coupled natural and human

systems are able to function together at a capacity that suits both the needs of the natural

environment and the needs of society. Most often dam removals occur as an effort to rehabilitate

the natural environment because of damage caused by anthropogenic changes. This study is a

contribution to the effort put forth to understand how society can better couple the natural

environment with human systems. The methodology proposed here will be applied to ensure that

future dam removal projects limit distress caused to the natural environment.

Currently one of the most controversial issues in wildlife management is the removal of

dams for the remediation of anadromous fish habitat. Anadromous fish rely on temperature

thresholds, baseflows, and spawning gravels, all of which are often disrupted or completely

destroyed on rivers with dams. One major issue concerning dam removals is determining how

accumulated sediment behind dams will disrupt the stream environment and for how long. In

order to make estimates about habitat disruption we must first determine how sediment waves

propagate and distribute through riverine environments. This study will focus on using structure

from motion photogrammetry to understand the spatial and temporal dynamics of a sediment

wave released after dam removal on the Klamath River. This research will address the question:

“Is sediment wave propagation occurring as a translational, stationary, or dispersive wave, and

what is the channel response”? This analysis will allow researchers to understand how the

channel is transporting and storing sediment which ultimately determines the success of

anadromous fish reproduction.

SETTING AND BACKGROUND:

Historically, the Klamath River was one of the most biologically productive rivers in the

western United States with an average population of 880,000 spawning salmon per year (1). The

mainstem Klamath River’s headwaters are in the Cascade Range near Klamath Falls, Oregon.

The mainstem stretches for 263 miles to the mouth in northern California near the

unincorporated community of Klamath, California. Native American communities have lived

and used resources along the river for over 4,500 years. Since the gold rush and colonial

settlement of the late 1800s water rights, irrigation rights, and litigation revolving around salmon

have been a constant problem on the Klamath River (1).

Construction of the first hydroelectric dam began in 1913 by the California and Oregon

Electric Company 198 miles upstream of the mouth of the Klamath River. This dam, named

Copco 1, was completed in 1918 followed soon by the completion of the dam Copco 2 in 1925.

With no constructed fish passage, these dams effectively blocked 175 miles of upper Klamath

River watershed to anadromous fish passage. In 1952 the Big Bend Dam was constructed 25

miles upstream of the Copco dams, increasing the total possible productivity of electricity to 80

megawatts. In 1961 the Pacificorp Company came into ownership of the Klamath Hydroelectric

Project including the three dams that had been built. In 1962 Pacificorp completed construction

on their final dam, Iron Gate, downstream of the Copco dams. Today, the dams together average

81 megawatts powering 1,400 farms and 70,000 homes. Including the mainstem Klamath River,

tributaries, and headwaters, these dams block a total of 300 miles of habitat for anadromous fish

(1).

Pacificorp’s dams are licensed through the Federal Energy Regulatory Commission

(FERC). License renewal began in 2004 and after determining that upgrading the dams to the

new environmental standard was ultimately not cost effective, dam removal became an option. In

2010 the Klamath Basin Restoration Agreement was signed by Pacificorp and the federal

government concluding that the dam removal process of all four dams would begin in 2020.

However, due to conflict between shareholders and the inability to settle the resource rights it is

still uncertain if the federal government will follow through with dam removal.

The area of focus is a local reach of Klamath River approximately () miles downstream

of the farthest downstream dam, Iron Gate.

RESEARCH PLAN:

Data processing will take place at Humboldt State University in the Geology Department.

Computer and lab facilities will be used along with contributions from students and staff.

According to (BLM) photogrammetry is the art, science, and technology of obtaining

reliable information about physical objects and the environment through the process of

recording, measuring, and interpreting photographic images and patterns of electromagnetic

radiant energy and other phenomena. Essentially, photographs of an object are taken at different

angles and then uploaded into a program such as Agisoft Photoscan which then mathematically

connects the pixels of each picture to create a three dimensional representation of the object.

These techniques can be applied to any scale in which the researcher needs. For this analysis a

drone with attached camera will be used to take aerial photographs of gravel bars.

Ten large gravel bars along with ten sections of the submerged channel will be

photographed for the analysis. Agisoft Photoscan will then be used to create “dense clouds”

which are point clouds of the data. Dense clouds are essentially the uninterpolated version of a

Digital Elevation Model. Baseline data will be collected for the bars the year prior to dam

removal. This is necessary to establish the elevation of the gravel bars prior to the sediment wave

transporting through the system after dam removal. Subsequent photographing will occur for

each bar and channel area once a month for the next year and dense clouds will be created for

each photomonitoring effort.

At the end of the year these dense clouds will be uploaded into Cloud Compare, a dense

cloud processing program that will overlay all of the dense clouds and calculate the elevation

differences between them. This will produce the changes in elevation that occurred on the gravel

bars over that year as the sediment wave that was stored behind the dam begins to propagate

through the reach. This will allow for the analysis of sediment wave propagation. The particle

size distribution can be calculated and along with the change in bar elevation and morphology

differences the rate of dispersal can be calculated along with an analysis of how quickly the wave

is traveling. It is critical for anadromous fish habitat that the sediment doesn’t suffocate the

system. This analysis will allow for a qualitative effort at predicting the risk of this happening.

One of the major issues of studying sediment waves has been the inability to measure

elevation changes of bars and beds at the resolution necessary to track sediment wave

propagation (Lisle 1997). The photogrammetry described here is a cost effective method that

provides the resolution required to track subtle elevation changes in great detail. According

to Matthews (2008), if the correct workflow is used, a resolution of 0.25mm and a spatial

accuracy equivalent of 0.025mm can be achieved.

Other methods have also recently shown great advancements in creating DEMs,

including terrestrial LiDAR. However, terrestrial LiDAR is orders of magnitude more

expensive than photogrammetry and cannot be used on a landscape covered by water. For

example, Westoby et al. (2012) applied both the photogrammetry technique and terrestrial

LiDAR to three study locations and found that photogrammetry paired with software similar

to Agisoft Photoscan produces better resolution than terrestrial LiDAR.

A preliminary test of the photogrammetric methods was completed in September

2015 on Jacoby Creek, at Brookside Bridge, Arcata, CA. A one square meter area on a

section of submerged gravel bar was used as a test site. Twenty seven photographs were

taken at different angles of the area and then analyzed in Agisoft Photoscan to produce a

dense cloud. At the Jacoby Creek site, a one square meter area was used because the purpose

of the test was to evaluate if photogrammetry is possible on a submerged bar. On the

Klamath River, the study sites will be much larger (on the order of tens of meters) to capture

expected sediment deposition along the full bar length and full channel width.

Figure 1.

Preliminary test results from Jacoby Creek in Arcata CA. Top figure shows the dense

cloud created from data points using Agisoft Photoscan. Bottom figure shows how the dense

cloud can be used to create a terrain model a gravel bars surface. The square of blue tape is

exactly one square meter.

OUTREACH:

Two educational conferences will be held at the Humboldt State University campus

aimed at informing the general public, students, and leaders in industry of the importance of

maintaining anodromous fish habitat. The conferences will be held six months apart the third

year of the project so some results can be shown. There will be a variety of discussion

sections that will cumulatively make up the conference. Discussion topics include but are not

limited to: 1) The application of photogrammetry in geomorphology, 2) Basics of

anodromous fish habitat and the reasons why it’s threatened, 3) History of the Klamath River

and future directions.

In addition to the educational conferences a special weekend workshop and project

will be held at Humboldt State University for professors and students to become familiar

with photogrammetric techniques and applications. The workshop will inform attendees

about different scales that this technology can be applied to and ideas on how they can apply

it in their individual fields. This workshop will allow the attendees to practice taking photos,

upload them to Agisoft, and make calculation differences in Cloud Compare. The workshop

will be held on two separate occasions, also during the third year of this project.

BUDGET

The items included in the budget are imperative to the success of this project and are

listed below in a table. The salary will ensure that the researcher has full time dedication to this

work. The graduate and or undergraduate students are necessary assistants for data collection and

processing. The drone, camera, computer, and software are the primary equiptment needed for

the photogrammetric analysis and data processing. Cloud Compare is free software so it is not

included. The publishing and conference costs will ensure that the research is displayed so it can

be contributed to the science.

Researcher Salary $30,000 per year Salary

Graduate Student Assistants

(2)

$6,000 per year each Graduate students or

undergraduate students that

help process data

Computer $5,000 one time Computer with high storage

capacity and RAM

Agisoft Photoscan $2,000 one time Needed for photo processing

Camera $500 one time Camera needed for

photogrammetry

Drone $3,000 one time Arial drone to mount camera

on

Specialized Scale Bars $500 one time Scale bars designed by the

BLM and automatically

recognized in Agisoft

Conference Costs $1,000 twice For the presentation of

research along with food,

lodging, travel costs

Publishing Costs $400 Fees for submitting the

research for publication

RESEARCH SIGNIFICANCE:

The application of photogrammetry is a potential way to quantify the effects of

sediment wave propagation in rivers and streams that are critical to healthy fish habitat. This

work could inform future dam removal projects, gravel augmentation projects, and habitat

remediation projects specifically by: 1) improving understanding of how large amounts of

material move through river systems, which can help on managed rivers to limit habitat

disruption , 2) improving understanding of sediment wave propagation, which can make

more accurate predictions of how much, when, and where to introduce sediment, and 3)

development of a photogrammetric methodology for studying sediment transport, which

opens new avenues for the application of this technology in fluvial geomorphology and

habitat restoration.

REFERENCES:

Blumm, M.C. and Erickson, A.B., 2012. Dam Removal in the Pacific Northwest: Lessons for the Nation. Environmental Law, 42.

Lisle, Thomas E. 1997. Understanding the role of sediment waves and channel conditions over time and space. What is Watershed Stability: 23-25.

Matthews, N. A. 2008. Aerial and close-range photogrammetric technology: providing resource documentation, interpretation, and preservation. Technical Note 428. U.S. Department of the Interior, Bureau of Land Management, National Operations Center, Denver, Colorado: 1-42.

Westoby, M. J., Brasington, J., Glasser, N. F., Hambrey, M. J., & Reynolds, J. M. 2012. ‘Structure-from-Motion’photogrammetry: A low-cost, effective tool for geoscience applications. Geomorphology, 179: 300-314.