Google Earth Engine Tutorial-29: Otsu Thresholding for Water Body Detection

code link: github.com/Ami...

[@okaagastya3635]

good tutorial appreciate

[@amirhosseinahrarigee]

welcome. thanks for the feedback. please share the content and channel with your friends.

[@stephenomar3650]

Thank you very much sir. You are doing a great job. Your content is very helpful! 🙏

[@amirhosseinahrarigee]

happy to hear that. please share the content and channel with your community.

[@wndcndra8752]

Thank you, you help me a lot for the script

[@amirhosseinahrarigee]

Welcome. please share the content with your community. Will try to share more tutorials.

[@Halal_hacks]

Truly best video

[@amirhosseinahrarigee]

Thanks. please share the channel with your community.

[@user-eu6ii9ju4q]

great work....what if the threshold values is a range within the adjusted histogram .....

[@amirhosseinahrarigee]

put the otsu function in a loop to get the threshold for each time

[@ekawahyuningsih_23]

What is the content of 'users/OEEL/lib:loadAll' ? and how do I find the library in GEE? and I have tried it but the error is like this "In users/OEEL/lib:/internal
1-th input should be of type for ee.ImageCollection, but was ee.Image"

[@amirhosseinahrarigee]

Please check out this website: www.open-geocomputing.org/OpenEarthEngineLibrary/

[@vasilica-danuthorodnic9667]

It is possible to apply this method in order to be able to delineate built-up areas from bare soil? (because the twi types of land cover present a similar spectral response).

[@amirhosseinahrarigee]

Yes it is possible but the input file must be a urban built up index. Have you see this tutorial:
ruclips.net/video/vutyioErpHQ/видео.html

[@vasilica-danuthorodnic9667]

@@amirhosseinahrarigee, It would be interesting te create a script where we generate our built-up index and bare soil index from Landsat datasets and then to apply the Otsu threshold to delineate built-up area.

[@ElaheZafarian]

I used this code for the the Normalized Burn Ratio. But I gut "Error generating chart: User memory limit exceeded' and 'User memory limit exceede'.. can you help me

[@amirhosseinahrarigee]

Hi, reduce the volume of data or area of region.

[@uma9183]

Sir, ocean salinity mapping using GEE

[@amirhosseinahrarigee]

this video: ruclips.net/video/VTN-mIco-wU/видео.html

[@user-rb1fr7ob5j]

How do you have it so that when you write code you get tooltips, i.e. writing options?

[@amirhosseinahrarigee]

press ctrl+space

[@utsavpoudel7034]

I got error message 'Computation timed out'. What can i do now sir?

[@amirhosseinahrarigee]

quit from code editor and enter again.

[@khaledalkaraki732]

Thanks dear. Could you make video about image fusion for the data especially MODIS 8-days with 500 m to be 10 m based on sentinel 2? and thank you again ❤

[@amirhosseinahrarigee]

welcome, will try to make fusion related tutorials in google earth engine.

[@AgriCo-lab]

Thank you so much fro this awesome vedio.
could you please cover monthly forest fire please .

[@amirhosseinahrarigee]

Thanks for the feedback. will try.

[@utsavpoudel7034]

//Load Area of Nepal
var country = ee.FeatureCollection("USDOS/LSIB/2017")
var table = country.filter(ee.Filter.eq("COUNTRY_NA","Nepal"))
Map.centerObject(table, 6)
//Load NASADEM
var image = ee.Image("NASA/NASADEM_HGT/001")
var elevation = image.select('elevation')
Map.addLayer(elevation.clip(table),{},'Elevation')
//Elevation above 3600m
var elev3600 = elevation.gt(3600)
Map.addLayer(elev3600.clip(table).updateMask(elev3600),{},'Elevation3600')
//Load Sentinel-2a data and filter by date and region
var sentinel2 = ee.ImageCollection("COPERNICUS/S2_SR_HARMONIZED")
.filterDate('2022-01-01','2022-12-30')
.map(function(img){
var bands = img.select('B.*')
var ndwi = bands.normalizedDifference(['B3','B8']).rename('ndwi')
var ndwielev3600 = ndwi.updateMask(elev3600)
.reproject({
crs: 'EPSG:4326',
scale: 500 // Downsample to 500 meters
});
return ndwielev3600.copyProperties(img, img.propertyNames())
})
Map.addLayer(sentinel2,{},'Sentinel-2a')


// Import OEEL library
var oeel=require('users/OEEL/lib:loadAllSF')
// Apply Otsu Threshold
var otsu = sentinel2.map(function(image) {
return oeel.ImageCollection.OtsuThreshold(ee.ImageCollection([image]), 'ndwi');
}).mosaic(); // Combine the thresholded images
print(otsu)
print(
ui.Chart.image.histogram(otsu,table,500)
)

var thr = ee.Number(otsu.reduce(ee.Reducer.mean()).reduceRegion({
reducer: ee.Reducer.mean(),
geometry:table,
scale:500
}).values().get(0));

print ('water body threshold', thr)

var water = sentinel2.mean().gt(thr) // Apply threshold to the mean NDWI image
Map.addLayer(water.updateMask(water), {palette: 'blue'}, 'Water Bodies')
Can you please look in this code and edit this? I keep getting user memory exceeded and computation timed out.

[@Ramilacookware]

سلام دوستان یه سوال علمی دارم .
من اگه با اکسل trendline یه فایل csv بدست بیارم از اون یه معادله بیرون بکشم R2 شاخص خطا تناسب معادله با خط مثلا ۹۰درصد بشه ،
آیا از روی اون معادله میشه پیش بینی کنم ?
(یا حتما باید با پایتون کلی رگرسیون با NUMPY ... بزنم )
ببخشید سوالم خارج از موضوع بود🙏

[@amirhosseinahrarigee]

با سلام . متاسفانه اعضای این گروه تخصص آماری ندارند. با عرض پوزش از خدمت شما.

[@space-time-somdeep]

Thank you sir

[@amirhosseinahrarigee]

Welcome

[@uma9183]

Coastal Strom mapping using Google Earth engine

[@amirhosseinahrarigee]

Coastal monitoring tutorial: ruclips.net/video/Bkck4a7wKYg/видео.html