I have been studying keyline design time ago. Now I am trying to carry out a project and some friends have asked me to share with them what I understood . Tidying ideas have emerged some doubts :
1 - I have difficulty understanding the relationship between keyline pattern and keyline diversion channel . Because if we build a dam on a key point and the diversion channel in the key line . Can we do the key pattern line above it?
2 A valley may have more than one key point? I have a valley that becomes soft and softens again later
3 - If the key line is far a way below the work area you should take a guide line? How do I find it?
I would be grateful for comments or references.
Thanks in advance
Yes, I've seen them , they are great inspiration! That 's great that Darren take time to help apprentices
I also read a couple of books Yeomans(W.F.E.F. y CH.O.L), Eugenio Gras book(I am a Hispanic speaker), Regrarians Chap 1 and 2, and articles like "Understanding the Application of Keyline Geometry", "Applying Keyline to ripping, sowing and tree planting", etc.
But i didnt found this answers, maybe y lost them becouse my inglish is not so good. I feel like yeomans books are like split in parts, but is dificult to me understand the big picture of this issues.(thats videos help me a lot!)
1)Chanel whit patern, I never saw a diagram that showed as is the pattern and diversion channel together, always read separately and want to be sure how it works.
2)Guideline, becouse I think I have a vallie whose key point is far below, well outside the work area in a forest full of thorns , so I'm looking for another pattern.(O the vallie has two key points , I guess this does not exist , because I never heard of it , there are two minor points where the slope softens, but not very markedly , then softens hundred meters below the work area) It is a theoretical question , as it was in eye sight, I will make the topographic survey soon.
3)And now I'm with some hesitation on the simplification of patterns , I have heard that is not so simple and may even be dangerous , and I had stayed with ideas from "Understanding the Application of Keyline Geometry", I like the idea of simplificarpatrones and use straight lines, but not sure what kind of care should be taken in this regard
I will give your question a shot. Here is how I have done keyline design before
1. You pick one of the keypoint, don't worry too much about which one at first.
2. From the keypoint, you find your keyline on contour, and then you move it to have about a 1% grade (this is Mark Shepard's variation) towards the ridges.
3. Above and below the keyline, you put parallel swales at a distance that makes sense for you (factor of 2 the size of your equipment). If you picked your keyline correctly, the following swales will move water from the valley to the ridges. You might need to make some adjustments, but overall it should move the water in the right direction.
The real trick is not too worry too much, lay the lines with flags, observe and adjust if it does not work at first. One keypoint might allow to design the whole field, while others might make it harder.
Where you need to be careful is not with the layout as much as the depth of the swales. They need to be in proportion to your catchment area.
posted 5 years ago
HI Adrien, thanks for your shots!
In this case I find myself doing keyline irrigation of pastures and working with verical plow and irrigation overflow, so do not make sense swales.
I never heard of making swales with keylines, maybe if you dont have dams could be, for the first line a big swale.
If you have dams most of the runoff is stored in the dam, and only the water that falls on the surface of the irrigation area itself must be handle.
I was talking about the disersion chanel, which collects water from the catchment area for the dam.
I've been studying more and I have found some answers to my questions that make sense to me, I share them, but be careful who read it were my conclusions, I could be wrong.
1 - The pattern can be made or not above the diversion channel as if the catchment area will be worked. For example, in the regrarians image that they have in facebook(Image), there is three diversion channels , over the first is one catchment area , as it is planted thick with trees , in the following two are catchments and irrigation simultaneously , as are used for planting or grazing. That image is greate, explain a lot for me, i hope is correct.
2- I think you can not have more than one keypoint in a valley, but there may be more than one point whit keypoint form. In case there is more than a point where it seems to be a keypoint, the higher is the keypoint becose the curve tend to close as it is copied down.
3 - If no key point is or this is well outside of the work area a guide line is used. This is usually on the top of the valle, since repeating the pattern down the curve tends to close and therefore expels the water. But you should check the topographic map if that patern make the goal.
As with the keyline this pattern joins in the division with the slope by repeating up the last curve of the hillside.
I think what you call diversion channels are what I call swales.
In this image, the trees in the middle are planted along the swale, and the swale follows the keyline pattern.
posted 5 years ago
Ok, i dont understand becouse you tell me about move the water to the ridge whit the swales, but the diversion chanels are for collect water to the dam. Probably, if the dam is in the valley as is usual and cheaper, they move the water in that direction.
Keyline is about storage water to be abailable for the dry season, not infiltrate.
My understanding of keyline is that half the point is to bring moisture out to the ridges to keep moisture levels even and increase overall growth/fertility. So yes you want to move water out to the ridges. The pond would be to hold onto any excess water that the soil can not absorb and then redistribute it latter. The best place to store moisture is first in the soil, you don't have to worry so much about evaporation that way and it is instantly available to fuel plant growth. That keypoint dam is there to hold onto the excess that would otherwise be leaving your property.