I am so glad to see your videos, but why you select Kajaki Dam for your working area?
@GeosearchInternational
4 ай бұрын
Hi Atiqullah, Kajaki is the most important dam in the Helmand River Basin & also there are some interesting studies already completed by the USGS. I wanted to see if they can be replicated using open source data. For example, see my video on the evaporation losses of Kajaki dam. All the best, Andreas
@habibpopal9270
2 ай бұрын
I think the results for your volume is 5100 MCM which is a large number compared to the actual reservoir capacity 1700 MCM.
@GeosearchInternational
2 ай бұрын
Hi Habib, the maximum capacity @ 2 metres above the spillway is around 1485 MCM. That is an SRTM elevation of 1020m, or an arbitrary project elevation of 1035.5m. When we make the Elevation-Area-Capacity curves we will always include elevations which are way above the maximum fill level. In this case I have gone up to 1050m SRTM, which would give a volume of 5063MCM. Of course this is just theoretical. The reason for extending the curves is in case some politician decides that it would be a good idea to increase the dam height by "x" metres. I think there were some plans to do this for the Kajaki. If the curves are ready, it is very fast to see the impact of this in terms of flooded land area, and increased evaporation losses from the larger surface area of the reservoir. All the best, Andreas
@kalm1531
Ай бұрын
Well done man!
@GeosearchInternational
Ай бұрын
Thanks @kalm1531 all the best, Andreas
@africanahills2851
Жыл бұрын
Great video Mr. Andreas. Watching from Kigali, Rwanda. I am a dam engineer. Keep it up. One Question: We are facing issues of measuring/estimating sedimentation levels/volume in our existing reservoirs such as the reservoir of Nyabarongo I hydropower project (location: -1.989096°, 29.633219°). Apart from Bathymetric survey, Any other method can you propose to us in the estimating sedimentation volume within a reservoir? Thx
@GeosearchInternational
Жыл бұрын
Hi @africanahills2851 Glad you like the video! I have travelled through Rwanda many times en route to Bukavu in what used to be called Zaire. A beautiful country! Regarding sedimentation issues in reservoirs, I think that is the most important issue after evaporation losses. Bathymetric surveys are expensive, but what you can do is to look at Sentinel satellite images and map the water area at different times, especially when the reservoir levels are going down in the dry season. That way you will see the speed of sediment build-up over the years. The best way to do this is via the Google Earth Engine, but you will need some programming skills. You could also do drone surveys if you need more details. Have a look at: Guidelines for Developing Reservoir Sedimentation Monitoring Plans www.usbr.gov/tsc/techreferences/reservoir/GuidesForDevReservoirSedimentationMonitoringPlans_09-2021_508.pdf Reconnaissance Technique for Reservoir Surveys www.usbr.gov/tsc/techreferences/mands/mands-pdfs/ReconnaissanceTechniqueResSurveys04-2006_508.pdf Good luck & all the best, Andreas
@africanahills2851
Жыл бұрын
@@GeosearchInternational Great quick feedback and explanations. I will go through the shared material/documents. Thx a lot. I appreciate your contribution
@GeosearchInternational
Жыл бұрын
You are most welcome! All the best, Andreas
@frenchcookerysnob8251
Жыл бұрын
As an engineering student specializing in hydrosystems management, your channel is the best thing that ever happened to me !
@GeosearchInternational
Жыл бұрын
Thanks for your kind words! All the best, Andreas
@therealist9052
10 ай бұрын
Exactly what I was looking for. Thanks so much!
@GeosearchInternational
10 ай бұрын
You are most welcome! All the best, Andreas
@bibhorbista9808
Жыл бұрын
1) Is it ok that I got a different result than yours while calculating surface raster volume? Is it because the SRTM images that we import from the plugin are of different time? 2) What does 'count only below base level' mean?
@GeosearchInternational
Жыл бұрын
1) There is only one SRTM30 digital elevation model of the world, so the only difference will be if you use a different polygon for your area, or if you have used the wrong method for the volume calculation. 2) Method: 1 - Count Only Below Base Level: only pixels below the base level will add to the volume.
@gmallikarjunaswamy9520
2 жыл бұрын
Please do more videos on geology topics,we r waiting , loved ur explanation.
@GeosearchInternational
2 жыл бұрын
Hi MALLIKARJUNASWAMY, This video is about a reservoir, but you can use the exact same methodology to work out the volume of a groundwater recharge basin, or an opencast mine. You could even use this approach to figure out the volume of a landfill or other positive topographical feature like a hill. What I would like to say is that all topics dealing with water are in the same family. We should not think that groundwater is separate from surface water. Many of the methods can be used for other parts of the water cycle as well. All the best, Andreas
@KKoKoRR
Жыл бұрын
3:11 You didn't change the CRS when save DEM. It is projected to ESRI 54034?
@GeosearchInternational
Жыл бұрын
Hi KoKoR - well spotted. Indeed it is a mistake. In Step 6, I extract the DEM using the polygon and then it is saved in the correct equal area projection. That is the reason why the end result is OK, though it would have been better to project the DEM at the start. All the best, Andreas
@enashamed3117
Жыл бұрын
Thank you for this video .its amazing and very useful.i want to ask you if this method can be used for lakes upstream barrages in river reach or for dams only.
@GeosearchInternational
Жыл бұрын
In theory yes, but I would be very careful with rivers as they are constantly changing their profiles, so I'm sure that the SRTM model of 2000 is very different from what it looks like today. All the best, Andreas
@Amadraniba
5 ай бұрын
This is great, how do i get the excel for this calcs?
@GeosearchInternational
5 ай бұрын
Hi Fred, the links to files are always in the description below the video: QGIS shape files & Reservoir DEM: bit.ly/3Lc70Ws EXCEL data & calculations: bit.ly/3unSTaz It opens in Google Drive so just click on the download arrow top right. All the best, Andreas
@frankodoom3360
2 жыл бұрын
please can i get the satellite imagery data of kajaki reservoir which is labeled, n32e065 1arc v3
@GeosearchInternational
2 жыл бұрын
Hi Frank, n32e065 is the 30m DEM which you can download inside QGIS. I think I explained how to do this in the video: kzitem.info/news/bejne/14Gau4qgfZuXd44 The satellite image in the video is just the standard ESRI satellite background. All the best, Andreas
@frankodoom3360
2 жыл бұрын
@@GeosearchInternational ok thank you sir
@GeosearchInternational
2 жыл бұрын
Welcome Frank, All the best, Andreas
@cusco4x295
2 жыл бұрын
Thanks for sharing your knowledge
@GeosearchInternational
2 жыл бұрын
It's my pleasure Cusco! All the best, Andreas
@anggitotria4582
Жыл бұрын
thank youuu! you helped me a lott!!
@GeosearchInternational
Жыл бұрын
You're welcome! All the best, Andreas
@engahmadansari1972
2 жыл бұрын
Thank you so much for the excellent work
@GeosearchInternational
2 жыл бұрын
You are very welcome Eng Ansari! All the best, Andreas
@peterserey7768
2 жыл бұрын
Thanks for sharing this wonderful work. I do have a question Can we convert elevation-area-storage capacity into depth-area-storage capacity? Please correct me if i am wrong. I think this would be an elevation level ID 2 - an elevation level ID 1 and accumulate them all together to the rest. Appreciate your through on this. Thanks
@GeosearchInternational
2 жыл бұрын
Hi Peter, sorry I don't fully understand your question. We can establish a relationship between any of the three key parameters: elevation, area and storage. In other words we can get a polynomial formula that describes elevation-area, area-elevation, area-storage, storage-area, elevation-storage & storage area. If you have depth data, I would convert that into an elevation of the water level that you can relate to your DEM. In any case water depth is not a good parameter to use, because reservoirs will tend to silt up so your zero depth level may change over time. The DEM and all the elevation-area-storage relationships also needs to be updated on a regular basis via bathymetric surveys or you will overestimate the volume in storage as it is reduced over time. This is quite an important issue for all reservoirs. All the best, Andreas
@peterserey7768
2 жыл бұрын
@@GeosearchInternational Sorry if i did not address my question well. Can we translate or derive the elevation of the reservoir from the DEM into the water depth level? thanks
@GeosearchInternational
2 жыл бұрын
Hi Peter, can you explain what you mean by "water depth"?
@peterserey7768
2 жыл бұрын
@@GeosearchInternational water level of the reservoir. Thanks
@GeosearchInternational
2 жыл бұрын
Hi Peter, The topic of my video is how to do this given old elevation-area-storage curves which are not using the same datum as the SRTM digital elevation model. If there is anything you don't understand in the video let me know. All the best, Andreas
@dvd5542
Жыл бұрын
Great tutorial thnx
@GeosearchInternational
Жыл бұрын
You're welcome! All the best, Andreas
@Tom-ks9xl
7 ай бұрын
This is Brilliant! Concerning the amount of repetitive commands it might be probably worth to either write a little plug in with python or so. That creates the table depending on z value. Maybe there is even already a plug in that we don't know
@GeosearchInternational
7 ай бұрын
Hi Tom, Glad you liked it. If you find a faster/better way do let me know! All the best, Andreas
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