Flood Mapping - Part4 (Earth Engine Guided Project)

This guided project is part of the End-to-End Google Earth Engine course offered by Spatial Thoughts. spatialthought...
This series of videos will take you through the entire process of building a script for visualizing and mapping floods using Sentinel-1 dataset.
Get the code from code.earthengi...

[@ezzrafarhan5074]

how to exactly decide the threshold value? can you explain it please

[@SpatialThoughts]

The values given in this tutorials are derived from US-SPIDER method and the given threshold is a good starting point. You can adjust it lower or higher based on visual inspection and correlating the results with ground truth. It is the analyst's job to figure out the threshold that makes sense for the flooding event.
There are automated thresholding techniques such as Otsu's which can help, but it also requires experimentation with different parameters to find out what works for your region. courses.spatialthoughts.com/gee-water-resources-management.html#otsu-dynamic-thresholding

[@vitorbarbosa6663]

Congratulations and thanks for the excellent tutorial. It is very helpful. I have a question: when I apply the filter for noise removal, several pixels are eliminated. I find it strange that this occurs homogeneously in horizontal strips and with this the image is left without an important amount of area for flood analysis. Is this normal?

[@DebaleenaChatterjee]

I am having an error saying "after_filtered is not defined"!! how to fix this and proceed?

[@tharjun9447]

sir pls give the coding script pls

[@SpatialThoughts]

See how to get code repository at courses.spatialthoughts.com/end-to-end-gee.html#guided-projects

[@tharjun9447]

@@SpatialThoughtsthanks sir ..sir can I also used the same threshold value in my study area .. Manipur..
pls reply sir🙏

[@UjavalGandhi]

@@tharjun9447Yes. Export the results and check the results in QGIS. Adjust the thresholds based on your observations

[@odebiriomosalewa2405]

Hello thanks for this video, one of the best I have watched. Please can you share the speckle filter function. the link to the code is not showing in my reader. Thanks

[@SpatialThoughts]

The code will be in your “Readers” section. See this to learn how to find it courses.spatialthoughts.com/end-to-end-gee.html#get-the-code

[@odebiriomosalewa2405]

@@SpatialThoughts .. Thank you so much for your prompt response.. I actually did that already before contacting you but the script wasn't visible in my reader... Please your help to get the speckle filter script will be much appreciated. Thanks