Downloading Digital Elevation Data (SRTM) from USGS EarthExplorer 

You are welcome :)

You're welcome!

Can you explain how you you put your DEM data (elevation details) in the HECRAS software? If possible, can you please give your contact no?

Great 👍

Wow, thank you

Hello, its great hear that the video was useful. Thanks for watching :)

Hi, thanks for your comment. Check whether this could be of some help to what your looking for? ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-MHuh4BxuR1M.html

@@geodeltalabs Oh yes, I actually slowed it down at one point while trying to coordinate my actions with the video. I've now got it so I can run through the process in QGIS "fairly reliably" by rote. I'm using 75m intervals (I know never to interact with GE while it's trying to load - it can load anything if you just leave it alone) and with that and the status bar figures it will make for increased avoidance of miscalculations. But I wonder: normally I calculate in feet in GE being in the US - because the result is 3.28084 x more accurate (ha, ha) but the starling thing is that the status bar figures corroborate VERY precisely with the old USGS Togoraphical Maps. Now if the tightest resolution of the (what is it?) "Year 2000 Satellite Survey" is 30m, then how is it Google Earth has such accurate figures in the status bar? I mean once I found a place it was MORE accurate than the USGS Topo Map - proven with Street View. (I expect surveyors sometimes got tired of being sick+tired back then, maybe they were doing some early experimenting with void filling.) It may be the best solution for my purposes would be from your video where you extend a path at length in approx grid to get the GE figures, and create a file using ArcGIS. But haven't gone through even a quarter of your videos on the subject. Like I say yesterday's results are very encouraging, because lacking in coding knowledge I was pretty much stuck in countries outside the US as far as getting a concept of the lay of the land, for the past 10 years. Putting the exaggeration at 3.0 and viewing skewed and close really doesn't make for a feeling of confidence in one's proposed rail alignments.

Glad it was helpful!

You are welcome :)

You're very welcome!

You are welcome

You are welcome! :)

Sir, Could you please make a session for the NDBI analysis using satellite image. Actually, want to know how we need to categorize the value that we gain from -1 to +1. There are many tutorial for the NDVI. But, I couldn't find the any tutorial about how to categorize the NDBI values ( like buildup, water bodies and vegetation) Or else please suggest anyway to find the buildup area distribution for any place. sir, It will really helpful for us I don't know whether it correct to ask here.

Hi, as the definition of the NDVI suggests, it's a measurement how well (or otherwise) a certain element in nature reflects the near-infrared light and absorbs the red light (NDVI = [NIR-RED]/[NIR+RED]). Healthy vegetation which happens to contain more chlorophyll content, tends to reflect more NIR and absorb more red light, making the numerator of the above equation go high, indicating the presence of healthy vegetation. Therefore, I would suggest that for general classifications of things like buildings , roads, urban areas etc, you may use a supervised classification method, and use NDVI only with an understanding on what it was meant for. Hope this clears things up at least to some level :)

Sir, Thank You for the reply. I really got it sir.

Also I watched the tutorial about supervised classification for the Landsat 8 image that you uploaded year ago. You mentioned a band combination description table in that video. can I use that for any satellite image ? Actually , I asked this question in that tutorial also sir, I couldn't get the reply for that. I am a undergraduate student, very interested to learn Gis and Rs after watched your channel. Thank You

@@kkethusha7666 Every Satellite image has a different band recorded by the sensor in recording individual bands, so Landsat 7 band combinations are different from Landsat 8

Most welcome

You are welcome

Always extract

Higher the resolution, the better... As long as your PC is strong enough to handle it :)

Hello there, are you referring to combining multiple tiles of SRTM data into one continuous raster covering the entire UK? or blending elevation data from different sources? The former would be much easier. Once you download the tiles, use 'Mosaic to New Raster' tool in ArcMap to combine the tiles to one raster, or 'Merge' tool if you are using QGIS.

The simple thing you have to do is to produce short videos and essential tutorials. Thank you!

Don't put any date range then check

Thank you. 😊

@@user-qy8zi8hq4v No it doesn't solve the problem... I Cannot click the results then

I don't think SRTM is available for recent years just yet. You may check the metadata to see the existing version's year

Please, I'm having issues with this. Did you later learn how to add it?

Hi, no it won't. This shows only the variations in surface terrain

same here

What sort of ta basemap are you using? and in which software?

As i read one another cmnt that in qgis there is prblm occuring to be fit the satellite image on the same coordinates of the any other image so i will prefer u to use arc gis

Hi, during the first few minutes of the video you would be able to see how to locate the data corresponding to an area that is of interest to you. You could either zoom into it or upload a shapefile or a KMZ file whoch demarcates your area of interest and based on that you would be able to go ahead and download the corresponding DEM tiles.

I think data with such a fine resolution may not be freely available to download

@@geodeltalabs yeah, since this comment, i've found 1m DTM for england and 1m arc for US of A

not only SRTM, how can I get any past DEM images of an area

Hi, I don't think the elevation data are available for multiple years as you have mentioned. You could try checking the metadata to see what year the data you downloaded belongs to

You may check my video on downloading SRTM data using SRTM Downloader plugin in QGIS. Its one of the easiest ways to bulk-download multiple tiles at once, for a specified area

@@geodeltalabs I will thank you!