1. Justin Tangen Valley City State University
Using Side Scanning Sonar to Map Bottom Substrate Features in North Dakota Rivers
Justin Tangen
Valley City State University

2. Introduction
The primary goal of this research is to map the substrate composition of a stretch of the Sheyenne River using side imaging sonar
Using hands on inspections of 40 sites to confirm composition of the substrate
Using ArcGIS to process the data
Why?
We went down the river and used a feature on the Side imaging unit that logs a picture, GPS’s coordinate, and depth information. After a couple trial runs I had it set up to our liking and we did a final run and logged images and data for the whole route
After completing the stretch, the pictures were went through and decided to pick 40 sites that showed differing substrates that what we thought represented all the different kinds of substrates that the river could have. With the GPS coordinates, we set out with the Garmin and boat to do pebble count analysis
Using sonar in the future, now we will have a solid understanding of what is happening on the river floor when we decide to use it
Why- when we observe maps it goes empty when it comes to topographical features when it comes to rivers
With a better understanding of the topo of rivers and the substrates we can potentially use these SSI images to find habitats
Valley City State University

3. Side Scanning Sonar
Consumer grade side scanning sonar has made it more affordable to access this technology
Safer and faster than traditional substrate composition analysis
Due to debris, depth, and turbidity
Can cover ~6 miles per hour, in comparison to ~1 mile per day
In the past this technology was primarily used by ocean vessels and in larger lakes and rivers where the transducer is towed a certain distance behind the boat to map the substrates
Now they have it where it is incorporated onto the boat
Only time we could go out before was when river was low enough t
This can help us in dangerous areas
Valley City State University

4. Side Scanning Sonar
Here we can see a rudimentary image of how the sonar gathers the data
Side scanning shoots a thin sonar beam at 180 degree column to the left and right of your vessel
This beam is able to travel up 240 feet on each side of the transducer; 480ft of coverage total
The right image shows the path the boat took at the top the dark column beneath the line is the water column, and the more reflective surface is the bottom of the river
Valley City State University

5. Equipment Humminbird 1199ci HD SI Garmin GPSMap 78 Porta- bote
Receiving power supply from 12v deep cell marine battery
Garmin GPSMap 78
Connected to Humminbird via NMEA connection
Margin of accuracy ~3-5 meters
Porta- bote
Outboard motor

6. Equipment
The porta bote was nice as it meant we didn’t have to unload into the river. The lightweight meant that it could be loaded into a van along with the rest of our equipment and then easily drug down to shore.
The humminbird unit had an onboard gps unit, but using the garmin allowed us to log trackfiles and waypoints more effectively so we had it connected via nmea cable
Valley City State University

7. Equipment
This shows the configuration of the boat when we went out logging. The man in front was used to weight down the front to keep the transducer in the water and to watch ahead and alert me if we needed to veer from the center and to pull the transducer if it got too shallow. As for myself my job was to keep the boat centerline and to use the Humminbird system to log images every three seconds.
Valley City State University

8. Methods
Maintaining river center to gather the best depth data and to get the best coverage of both banks
Using the snapshot feature on the sonar, logging images every three seconds
Gathering quality images that overlapped
Reason being we wanted to have plenty of images when we went to put them into Arc
Valley City State University

9. Methods Uploading to excel for formatting and data entry
Pebble counts at 37 of the waypoints to compare substrates to the side scanning images that were gathered
Inputting pebble count
Pulling info from gps and sd in sonar
Valley City State University

10. Research Area
We focused in on a certain ~6 mile stretch of the Sheyenne that VCSU known very well due to prior mussel sampling runs that have been completed.
This ran between the low head dam in Kathryn and stopped at Little Yellowstone Park on the Barnes county and Ransom county borders.
Here we can see the track of the boat in the green
Valley City States Prairie Water light red
Dark red- 37 sites that we gathered images for
Valley City State University

11. Side Scanning Sonar Site 16
Make sure to reorient them so they know what they are looking at
On the river right we can see the substrate appears to be sand
River center appears to be a finer substrate
River left appears to have larger substrate in the middle of its column then fines down toward the bank
Valley City State University

12. Side Scanning Sonar
Good example of what happens when the river narrows, and transducer is still trying for 80ft
Also directly under the boat we have a good example of a some elevation changes
Valley City State University

13. Side Scanning Sonar
Bridge pylons can be observed on the left and right of the river
Also this was one of the rockiest stretches of
Valley City State University

14. Summary
We are going to use our pebble count and ssi to create these types of maps
Valley City State University

15. Summary Geospatial analysis in ArcGis is ongoing
Working to create effective shapefiles that represent differences in the substrate
With this data we can now observe how the substrate changes over time

16. Thank You Funding Agencies Andre DeLorme – VCSU science chair
NASA ND Space Grant Program
Valley City State University SOAR program
Andre DeLorme – VCSU science chair
Lewis Weiland – VCSU research assistant
Jason Rowell
Michaela Halverson
Shannon Hone

17. Sources http://www.humminbird.com/Category/Technology/Side-Imaging/