I identified a portion of a small river river (~10km) in my region that went through significant physical changes after a recent forest disturbance, with meanders being cut through and new erosion and deposition areas. I would like to map river geomorphology and quantitatively assess physical changes through time to evaluate the impact of the disturbance.
Can you suggest published methodologies?
Dear Francois
You can do this by using remote sensing and GIS, through using historical Landsat images, this is in simple words.
But, it need high accuracy satelite images
An area of 10 sq km, or an area 10 km X 10 km ( 100 sq km )? Also, why not provide the envelope bounding box ( Lat/Long, Min/Max) of your area of interest, because that will inform exactly what data sources and/or ongoing data collection is possible, especially if time series is required. Even better would be a polygon of exactly the minimum boundaries being interrogated, this helps especially if your study area is perhaps already being imaged to support another research project(s) collection campaign. (Especially if it is here in the Pacific Northwest, with our huge variety of weather, relief, vegetation, etc.)
Thanks Michael John Patrick . The river reach length is ~10km, for a width of interest representing a ~200m buffer maximum.
My question is more about a method on river morphology analysis when it comes to assess changes to the river channel (i.e., migration) between multiple dates. My area is in BC, which is very well covered with data, so no concern about that.
Hi François-Nicolas,
In my opinion, it is interesting to persue an historical analysis of channel migraiton with historical aerial photography and satelite imagery to assess change through time, using decadal increment. You can use Landsat, Sentinel or other recent platforms with very high resolution (VHR) sensors, and conduct UAV survey for recent image. You need to first pick a proxy to digitize your shoreline; vegetation line indicating bank full level or active channel, for exemple. It need to make sense with the object of your research. Then, you can use tools like Digital Shoreline Analysis System (DSAS), Ambur project in R or other shoreline analysis tools. Also, if you are lucky, using LiDAR data and recent drone photograpmmetry DSM (UAV-SfM), you can asses volumetric change and outline river migration with deposition and erosion zone.
Here's a reasearch exemple recently published: Article Dynamiques hydrogéomorphologiques historiques et actuelles d...
I also suggest to read Thomas Buffin-Bélanger works.
Message me if you have further questions!
Merci @Samuel. Pas de Lidar, hélas. But thanks for your input, it's helpful! I'll check Thomas' work.
Hi François
You can study the geomorphology of this part of the river, using two digital elevation models (DEM), the first being old and the second modern, then extracting the water network, and the characteristics of elevation and slope. You can also use a number of satellite images, then classify these images, determine the course of the river, and then compare the maps that were produced from the satellite images to identify the change that has occurred in the main channel of the river.
Hi
You can use time series historical data to evaluate the geomorphic index alteration. Extract and precessing those satellite landsat data into ArcGIS software then modify and analyzed..
Hi,
on top of the mentioned suggestions, if you can get historical images from Landsat, orthophoto... that can help to reconstruct DEM. You can use Land evolution models (LEM) to analyze the morphological change, or simply check the Difference of DEMS (DoD). Currently, I'm using CAESAR-Lisflood to analyze channel morphological change in different time frame, it works well.
Merci beaucoup Timothée Jautzy
pour ta réponse. I'll give your papers a look.- Badges
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