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New Contributor
Posts: 2
Registered: ‎12-06-2019

calculating Water indices

Hello Everybody, 

 

we know that we can extract water body content Using NDWI index from Erdas Imagine 

 

But what if we need more details, more indices such as water salinity ( as we can meausre soil salinity )

or water tempreture ( Landsat thermal band doesn't help if we are dealing with small lakes or rivers )

etc..

 

So How we can calculate or just get close to it 

 

waiting your reply and we can discuss together the best senario or solution 

 

Thanks & Regards 

 

 

Highlighted
Technical Evangelist
Posts: 640
Registered: ‎02-02-2016

Re: calculating Water indices

Hi Moustafa,

 

If you are aware of water salinity and temperature indices that has been designed for particular sensors please share the formulas so that we can help you create a spatial model to implement them.


Kind regards,

 

Stephen Bent

Hexagon Geospatial Support

Highlighted
New Contributor
Posts: 2
Registered: ‎12-06-2019

Re: calculating Water indices

Hi Stephen,

thanks so much for your reply&attention

 

unfortunately I still don't have any formulas,


Actually I have an area of study "industrial lakes"
and I can get Water parameters through sensors in the lakes


the questions that i'm facing now :


1- how can I get an exact formula from in situ sensor measurments?
2- how many times shoud i depend on these measurments ?
3- how can i use satellite images to predict via DN values after that?

 

waitnig for your guidence 

Thanks & Regards

 

Highlighted
Contributor
Posts: 24
Registered: ‎06-12-2016

Re: calculating Water indices

Hello, hope this helps !

 

Normalized Difference Salinity Index (NDSI) = [1600:1700]−[2145:2185] / [1600:1700]+[2145:2185]

 

Wavelenghts: 1600:1700,2145:2185 ( ASTER: B4-B5/B4+B5 )

 

 

Source: https://www.indexdatabase.de/db/i-single.php?id=57

 

Best regards,

Marian