I remember watching this video back in high school five years ago for an ArcGIS project. Now five years later you've saved me again as I attempt to draw Thiessen Polygons for my junior level college hydrology class. Thank you twice for this video
I'm here because I work in GIS, and I've used Thiessen Polygons to create territories. I wanted to understand the math behind it, and this couldn't have been a simpler and more comprehensive video to show just that. Thanks!
You probably dont give a shit but if you're stoned like me atm then you can stream all of the new movies and series on InstaFlixxer. Been watching with my girlfriend for the last couple of months xD
Overlay the map onto a square grid and literally just count squares to get an approximate area for each region. Units for the area don't matter - they'll cancel out later anyway. Once you have each region's area, multiply the area of that region by the rainfall in that region. Add all of those products together. Finally, divide this by the total area of the entire map. This gives the average rainfall. It's really just a weighted average. For example, say you only have 2 regions. Region A has an area of 10 boxes and 25 mm or rain. Region B has 5 boxes and 10 mm or rain. The average rain would be (10 x 25 + 5 x 10)/(10 + 5) = 300/15 = 20 mm of rain.
That would be great! :) trevor_ray@wrdsb.ca Ironically, I just made this video for my grade 12 students to do a little assignment. I never thought anyone else would ever look at it!
It has helped a lot. I am in the analysis phase of my Bachelors Degree Research Project and have been looking for the best method with which to average the precipitation data from the weather stations surrounding my study area. This video has opened my mind. Thanks.
Please help me with a doubt, all the triangules must contain the point where coverges their mediatrixes? I have problems with harder problems where there are more triangules.
Thanks for the reply. Unfortunately I'm not familiar with that method. I actually just made this video to talk about calculating rainfall using some basic statistics.
This is just for rainfall average calculations. I don't think you can use it for drainage without breaking the region into separate water basins which would need more information about the topology of the region that you're looking at.
NIce video @Trevor Ray; and @Gonse amalo,You can get a concept of thiessen polygon in the following link, ua-cam.com/video/ECbUAVGnCNw/v-deo.html and you can use concept of Voronnoi polygons in GIS for drainge.
Just overlay any grid onto the picture and count the squares in each area. It sounds really approximate but gives surprisingly consistent results. I did it with a class of 30, and almost everyone got within about 1% of each other.
If you're talking about the last diagram, it's because B is between them. There's no point in connecting A and C since the breaks between A & B and B & C will override A & C.
I just can't understand. It is obvious with 3 points. However, when there are more than three, there is no pattern. I wish an algorithm to teach a computer how to do this automatically.
It doesn’t sound very scientific, but the easiest way is to put a grid on top of the picture and just count the number of boxes. Because everything is an approximation anyway, it works quite well. I had a class of 25 students try it, and almost all answers were within about 2% of each other. The smaller the boxes in the grid, the more accurate the results will be.
I remember watching this video back in high school five years ago for an ArcGIS project. Now five years later you've saved me again as I attempt to draw Thiessen Polygons for my junior level college hydrology class. Thank you twice for this video
I'm here because I work in GIS, and I've used Thiessen Polygons to create territories. I wanted to understand the math behind it, and this couldn't have been a simpler and more comprehensive video to show just that. Thanks!
Congrats sir, your videos have been used in my hydrology class
This was very helpful. I was struggling with how to do this but you made it a lot easier to digest and understand. Thank you!
The south park avatar shows me you are a man of culture. Thanks for the video, helped with my exam revision
straightforward and simple. Thanks for making such a good tutorial!
Man, I wish you taught my hydrology class.
You probably dont give a shit but if you're stoned like me atm then you can stream all of the new movies and series on InstaFlixxer. Been watching with my girlfriend for the last couple of months xD
@Ralph Jayceon definitely, I've been watching on Instaflixxer for since december myself :D
3yrs later
Helped in my civil services optional geography preperation....Thanx a lot for explaining this concept in a very easy way☺
Thanks for making these video. Because of you I can understand the concept of these methods. I am thankful to you 🤗
Damn, english is not my first language but still I can understand you way better than my actual brazilian teacher
Me too hahaha
This video cuts NEAT like a scalpel. Thank you.
Is video in 4 fps?
Why teachers at university can't teach us like people in UA-cam!!!!!!!!!! I got the whole subject in 10 min video
Trevor thank you for your video, now I am interested to know from here how do you average the precipitation data of catchment area?
Overlay the map onto a square grid and literally just count squares to get an approximate area for each region. Units for the area don't matter - they'll cancel out later anyway. Once you have each region's area, multiply the area of that region by the rainfall in that region. Add all of those products together. Finally, divide this by the total area of the entire map. This gives the average rainfall. It's really just a weighted average. For example, say you only have 2 regions. Region A has an area of 10 boxes and 25 mm or rain. Region B has 5 boxes and 10 mm or rain. The average rain would be (10 x 25 + 5 x 10)/(10 + 5) = 300/15 = 20 mm of rain.
Thank you so much. I will do so. I should like to share you the results of my research once am done. Would you mind sharing your email?
That would be great! :) trevor_ray@wrdsb.ca
Ironically, I just made this video for my grade 12 students to do a little assignment. I never thought anyone else would ever look at it!
It has helped a lot. I am in the analysis phase of my Bachelors Degree Research Project and have been looking for the best method with which to average the precipitation data from the weather stations surrounding my study area. This video has opened my mind. Thanks.
What if we connected D and C, instead of B and E?
So good Thanks a lot!!!!
This is amazing. Thanks a lot for the video.
How this method is useful to find out buffer zone around each primary health center and community health center. Plz explain it
Please help me with a doubt, all the triangules must contain the point where coverges their mediatrixes? I have problems with harder problems where there are more triangules.
so clear, thank u
Very straightforward and clear video, thank you :)
Can you also create a tutorial video for Isoyetal analysis method? Thanks! Great video by the way!
Thanks for the reply. Unfortunately I'm not familiar with that method. I actually just made this video to talk about calculating rainfall using some basic statistics.
Man very gud communication skills
so beneficial. thank you for make this video ...
Thank you
From Iraq 🇮🇶 ♥
Thanks a lot .now there are no more worries about Thessian polygan theory
Much better than my useless teacher,
Thank u
why aren't a and c connected?
How could i delineate urban drainage by Thessen polgon having different junction points?
This is just for rainfall average calculations. I don't think you can use it for drainage without breaking the region into separate water basins which would need more information about the topology of the region that you're looking at.
NIce video @Trevor Ray; and @Gonse amalo,You can get a concept of thiessen polygon in the following link, ua-cam.com/video/ECbUAVGnCNw/v-deo.html and you can use concept of Voronnoi polygons in GIS for drainge.
Thank you so much for this
Well explained!
Perfect mate👍👍......
how do I use the grid method to calculate?
Just overlay any grid onto the picture and count the squares in each area. It sounds really approximate but gives surprisingly consistent results. I did it with a class of 30, and almost everyone got within about 1% of each other.
@@trevorray831 thanks I appreciate it 😍
thank you brother.
thank u soooo much bro.....This video helped me a lot to understand the actual concept.
Y is the video lagging
Thank you so much!
why u not join gauge c and A
If you're talking about the last diagram, it's because B is between them. There's no point in connecting A and C since the breaks between A & B and B & C will override A & C.
I just can't understand. It is obvious with 3 points. However, when there are more than three, there is no pattern. I wish an algorithm to teach a computer how to do this automatically.
@@brenoarruda2996 there are algorithms to construct Thiessen polygons.
Simple and nice
Thanks a lot sir
Thank you
thats-perfect
how to solve area?
It doesn’t sound very scientific, but the easiest way is to put a grid on top of the picture and just count the number of boxes. Because everything is an approximation anyway, it works quite well. I had a class of 25 students try it, and almost all answers were within about 2% of each other. The smaller the boxes in the grid, the more accurate the results will be.
Helpful
What if there is no point e.
Then the lines between B & D and B & C get extended downwards until they meet, and you have to another perpendicular bisector between D & C.
Useful
Sweet!
very helpful tyty
thanks
Great at simplifying thigs! :D
Do everyone come here for their Hydrology class?😂
thank u..
Nice..
please for example
I peed my pants
Me too bro
why so lag
I had a really bad document camera.
Hello sir
gabisa bhs inggres
PANCEN CELENG
aap ne hote to kya hota
Thanks