Subject: Dear All, How can delinate the catchment for Egypt only not for the whole Nile River Basin? Posted: 4/26/2019 Viewed: 7467 times
Dear All,
Kindly, I try to delineate the catchment for Egypt but the result was the catchment for the whole Nile River Basin, How can delineate the catchment for Egypt only not for the whole Nile River Basin? Or Egypt has not Catchment because it is a downstream country?
Thank you
Mr. Miroslav Kandera
Subject: Re: Dear All, How can delinate the catchment for Egypt only not for the whole Nile River Basin? Posted: 4/26/2019 Viewed: 7330 times
Hi, there is way (not very easy, but possible). I am not using Catchment D.M., yet i was curious about its possibilities and limits and so i found a way (not sure if it is official method but i didnt found any errors caused by doing it like this).
https://youtu.be/vCZHaAjBgM4 I recorded very short video describing it (without voice comment) so i will write process here:
1). click on "Set area boundaries"
2). Select small area where you want end of your catchment to be. This is very tricky because if you need to select whole catchment of certain river which flows to main river, you need to put border of your area boundaries to the right spot
3). to help with it, when you select "Catchment delineation mode", you have there shown (as i pointed in video) how many cells "flows" into cell you are pointing at. To find cell which is last cell of your river, find two cells between which difference of cells floating into them is visibly greater then difference between cells before. (i will do when there will be more time another video describing it more in detail with voice comment)
4). when you ll find a cell you want your catchment to end there and you will set boundaries right, you just click at that cell, give catchment/river name and it will delineate it properly
It is little tricky if you want it absolutely right, and there is also problem, that it doesnt affect creation of river object. To deal with it, i tried to delete river points from end of my catchment downstream, and it works. You need to open GIS file created by WEAP by ARCGIS or QGIS and manually delete part of river you dont want there. No errors, but i think deleting whole river and manually creating new one and then connecting delineated catchment to it will cause few. certainly i will record a video, and not only about this topic :) there is many other things...
Yet if there is easier way or if later can this method cause any calculation or other WEAP errors, please let me (and basically everyone) here know, will appreciate it.
Good luck
Mr. Amirhossein Dehghanipour
Subject: Re: Dear All, How can delinate the catchment for Egypt only not for the whole Nile River Basin? Posted: 4/29/2019 Viewed: 7221 times
Dear Mido,
You can build a watershed for Egypt. You can use Arc GIS for this. The first, you should separate Dem of Egypt and after that use this video in the below link.
https://www.youtube.com/watch?v=vzBzs3zeMyU
Best,
Amir
Ms. Anne Hereford
Subject: Re: Dear All, How can delinate the catchment for Egypt only not for the whole Nile River Basin? Posted: 6/19/2019 Viewed: 7215 times
You can also try subdividing the catchment and then delete the upstream catchments. To subdivide an existing basin, hold down the ALT key and click on the main river upstream of the pourpoint at the location you are interested in. Keep in mind that if you eliminate a large portion of the basin upstream, you will need to input the flows from this portion of the basin as headflow. WEAP will not be able to represent the full river flows without knowing the upstream (outside of Egypt) basin area.
Mr. Mido Wakeel
Subject: Re: Dear All, How can delinate the catchment for Egypt only not for the whole Nile River Basin? Posted: 1/15/2020 Viewed: 6479 times
Dear Mrs, Anne,
Thank you so much for your reply. Actually, I tried it and it subdivided the catchment but when I try to delete the upstream catchments it delete the whole basin, do you have any idea how can overcome that?
Thank you
Best Regards
Mr. Mido Wakeel
Subject: Re: Dear All, How can delinate the catchment for Egypt only not for the whole Nile River Basin? Posted: 1/15/2020 Viewed: 6476 times
Dear Mr. Miroslav,
Thank you so much. I watched the video and I understand what you meant but it does not work with me at all. could you provide me any idea to overcome it?
Thank you
Best regards
Mr. Mido Wakeel
Subject: Re: Dear All, How can delinate the catchment for Egypt only not for the whole Nile River Basin? Posted: 1/15/2020 Viewed: 6473 times
Dear Amir,
Thank you. Yes, I can extract it using the ArcGIS but you will use it as a background layer only not in automatic mode in WEAP.
Thank you
Topic "Dear All, How can delinate the catchment for Egypt only not for the whole Nile River Basin?"
