Finding contour on uneven land

Hello Everyone

I think I understand how an A-Frame level and a Bunyip level works. What I don't understand is how to use either of them on very uneven land. My land is mostly flat. The northern part has a gentle sloop.

The relatively flat part of the land is very uneven. It's been logged and plowed and terraced then logged again over the years such that it is very bumpy. How do I use an A-Frame level when the land has foot to two foot bumps running all through it?

Any advice would be greatly appreciated.


Jeff
SC Low Country

Hmmm....I guess I will wait for others, as perhaps I am missing the nature of the query. Unless I am creating a contour map at a detail level and scale of an "orienteering map" I do not bother with minor topographic anomalies like land that, "...has foot to two foot bumps running all through it." These are just "annotated," and/or remove with heavy equipment during the "grading process." Sorry if I missed the point?

Hello Jay

Thank you for your time. I agree that such minor topo features will be graded away. My question is how do I use the A-Frame on such unlevel land prior to the grading. It seems to me those bumps will make the A-Frame work totally inaccurate. Do I level the ground in the area I'm searching for the contour prior to using the A-Frame? I'm just a bit confused.

Many thanks

jeff

I have the exact same question raised above - which no one has addressed yet (at least in this thread - maybe it is somewhere else on permies?)

I have a small area in a vegetable garden, that has 4 parallel raised beds (17' long), the last 2 not very clearly defined anymore, more like a pile of raised soil. I know the direction of the overall slope of the land and would like to create swales on contour, but I am stumped as to how to use the A level in this situation, with the piled up soil surface.
Should I pile up this raised soil to the side, trying to make the surface "flat" and then use the A frame?

If the surface of the ground is too rough to function with an a frame level then you may have to find places in elevation that appear to be the average elevation of the area around it and take note of them. If you do this selectively all across the area you wish to survey it will give you a rough idea of your overall contours and you can make informed decisions about where to begin with your earth work. Once you begin moving earth, like Jay c. said, then you can grade things and use your a frame to level your swale and all that.

Jeff:
Maybe I'm missing something, but if I understand both your and Susanne's problem is based on the A-frame level being at a fixed distance and not able to span across a small dip or bump. Some of my suggestions will depend on the scale we're dealing with.

I would suggest if you are wanting to peg out a contour line on very "bumpy" ground I would use a bunyip with at least 20 feet of tube between the stakes or use a laser level. This way you can vary the distance between the contour pegs you put in the ground to accommodate (go past) the bumps and tire tracks.

Remember, contour lines aren't something that go where you want them to be, there are what they are, imaginary lines made up of points along that line that are at the exact same elevation. With this understanding, bumps aren't something that aren't in your way, they form part of the landscape and cause your contour line to curve. Now, as JC suggests, you can level them out. But, if you can put in your contour pegs at different distances, say every 10 feet until you see that the bump would cause the level to swing to what appears to be down hill, you can stretch your bunyip level or laser post farther than the bump or tire track (maybe 15 feet) and find that contour point on the other side of it and then you simply have a contour line that you can imagine going though the bump that you will come back and level out as JC suggests.

Susanne:
As I mentioned above, I would simply stretch my bunyip across your beds and find where the contour line continues on the other side. If you only have an A-frame level, go ahead and simply clean out the soil in your bed only big enough to accommodate where the leg of the A-frame level will reach and only deep enough to allow the tool to indicate level. Make your best guess where it would naturally fall if there were no raised bed. Don't worry, you're going to find the level on the other side. Then, flip your A-frame level to get to the other side of the bed and mark the next contour peg on the other side of the bed.

If I've misunderstood the problem, please disregard. As powerful as the written word is, we can still not grasp or read between the lines of what the other person is saying.

Blessing,
Dan

Dan Grubbs wrote:Jeff:
Maybe I'm missing something, but if I understand both your and Susanne's problem is based on the A-frame level being at a fixed distance and not able to span across a small dip or bump. Some of my suggestions will depend on the scale we're dealing with.

I would suggest if you are wanting to peg out a contour line on very "bumpy" ground I would use a bunyip with at least 20 feet of tube between the stakes or use a laser level. This way you can vary the distance between the contour pegs you put in the ground to accommodate (go past) the bumps and tire tracks.

Remember, contour lines aren't something that go where you want them to be, there are what they are, imaginary lines made up of points along that line that are at the exact same elevation. With this understanding, bumps aren't something that aren't in your way, they form part of the landscape and cause your contour line to curve. Now, as JC suggests, you can level them out. But, if you can put in your contour pegs at different distances, say every 10 feet until you see that the bump would cause the level to swing to what appears to be down hill, you can stretch your bunyip level or laser post farther than the bump or tire track (maybe 15 feet) and find that contour point on the other side of it and then you simply have a contour line that you can imagine going though the bump that you will come back and level out as JC suggests.

Susanne:
As I mentioned above, I would simply stretch my bunyip across your beds and find where the contour line continues on the other side. If you only have an A-frame level, go ahead and simply clean out the soil in your bed only big enough to accommodate where the leg of the A-frame level will reach and only deep enough to allow the tool to indicate level. Make your best guess where it would naturally fall if there were no raised bed. Don't worry, you're going to find the level on the other side. Then, flip your A-frame level to get to the other side of the bed and mark the next contour peg on the other side of the bed.

If I've misunderstood the problem, please disregard. As powerful as the written word is, we can still not grasp or read between the lines of what the other person is saying.

Blessing,
Dan

thank you for the input dan that really cleared up the proper way to work around bumps with a bunyip for me ive been thinking that through for a larger project in mind lately and that definitely cleared it up for me:)

I'm really glad it was helpful, Devon. Be sure to post some photos of your work as you progress!

I have had the exact same issue with my A-frame level. The bunyip looks like the solution.

Thank you Dan! I was wondering about this myself, it must be such a common question.

As I've read back over my postings, I now want to make something clear. I'm in no way disparaging A-frame levels. They are an amazingly simple, yet powerfully useful tool that can be used by one person and can be assembled out of primitive elements found on nearly any landscape. They are a great project to make to introduce someone to earthworks. I think the key is that there are various tools we can choose for various jobs and some are better suited for different conditions and situations. When should I choose a combination wrench over a socket wrench? The right tool for the right job. Then, when you add in what you actually have on hand or readily available to you and how you will use a tool going forward, these are also factors in what tool you choose to have in your metaphorical and literal tool box. One of the drawbacks of a bunyip level is the need for more than two hands and more than one set of eyes. I will be bold and recommend that even a "potato" should be a master of building and using both the A-frame and bunyip levels.

Which actually brings up an interesting discussion topic suggestion, which is sort of aligned with the "potato" volunteer discussion thread: What tools are an absolute must for a permie location?

I'm gonna have to look up this tater business now.

I would agree that the Bunyip is the best solution. I would add to this as a visual or a general reference. One could use a string level stretched between two stakes and leveled to gravity with a spirit level. This is the same technique a fence builder or mason would use. Two points on the earth with a taut line adjusted up or down until a bubble level shows level to the gravitational field of the earth. "X" units of measure below the string will be level "on contour" regardless of what bump of divit is below the string. One can level or fill appropriately. Or drive a stake and mark the string line with high visibility markings. Stepping back the marks on the stake line will show your contour line regardless of uneven terrain.