Looking for an app which I can use to show me the gradient of my land....

[Oxbow16]

Hi all

 

I've been out in the garden today measuring the undulating lay of some of the land.  It all slopes gently downhill, but to varying degrees in different places.  I have measured at different points and now have a bunch of "at this distance, the ground is this height" figures.  

 

It would be really helpful to visualise this and I wondered if there is some kind of on line "app" or similar which will allow me to punch in these figures and produce a visual representation of them.  

 

Anyone have any ideas?

 

Many thanks

[dnb]

I would create an array and plot them as a surface in Matlab (excel would do at a push), but I know this marks me out as weird.

[Oxbow16]

Thanks dnb...  I'll reserve judgement on the weird bit until I understand what you mean   

 

If you're able to explain that in a more dumbed down step by step I'd massively appreciate it.  I have excel.  In fact, I use it so often that I have been known as Maxcel in the past!  But a lot of its features I'm completely ignorant on.  

 

Cheers 

 

Max

(cel)

[dnb]

Would you mind sharing the data? I can knock up an example in a couple of minutes. It might not be exactly what you are looking for but there's not a lot to loose.

[SteamyTea]

Something like this.

Just punch in the numbers, use conditional formatting to colour in the cells after they have been resized so that height and width are equal.

 

 

Or chart it.

 

 

Edited October 22, 2020 by SteamyTea

[dnb]

 

Was thinking of a 3d chart based on data constructed as SteamyTea has done. There always used to be a 3d surface chart in Excel - just select the data grid and select the 3d chart option.

 

Here's an example from Matlab.

Edited October 22, 2020 by dnb

[dnb]

Here's an excel version. It is now called "surface plot". I was thinking about an older version of excel.

[Onoff]

I could create a surface mesh in AutoCAD with the data. This sort of thing. The survey ideally to be done with spot heights on a regular grid:

 

[SteamyTea]

13 minutes ago, Onoff said:

I could create a surface mesh in AutoCAD with the data

Your mum really should put your crayons away.

[Oxbow16]

What can I say... WOW!  Many thanks   I'm well impressed.  I only wish I had the data to do any of the above justice!  I don't though unfortunately.  All I have is length and height, so I was thinking more of a 2D plot of the data....  I'm more than happy to share the figures if anyone can do anything with them.  I have to admit though that - having never done anything like this before - I really was just making it up as I went along.  In hindsight, I should have measured at regular intervals rather than the random intervals I chose.  But the reason was because the land is very unimproved grassland and so I avoided measuring height where there were big grassy clumps or other irregularities underfoot.  

 

So here are those figures:

 

Distance CM	Height CM
140	15
330	30
510	39
750	45
1280	60
1520	60
1790	85
2020	97
2270	110
2530	125
2660	129
2820	132
2930	137
3130	137
3370	141
3650	137
3960	138
4000	145
4120	149
4290	147
4510	142

 

 

Huge thanks 

[SteamyTea]

What like this

 

 

[dnb]

I have a very similar chart... Labeled axes and everything.

height_profile.xlsx

Edited October 22, 2020 by dnb

[Onoff]

20 minutes ago, Oxbow16 said:

What can I say... WOW!  Many thanks   I'm well impressed.  I only wish I had the data to do any of the above justice!  I don't though unfortunately.  All I have is length and height, so I was thinking more of a 2D plot of the data....  I'm more than happy to share the figures if anyone can do anything with them.  I have to admit though that - having never done anything like this before - I really was just making it up as I went along.  In hindsight, I should have measured at regular intervals rather than the random intervals I chose.  But the reason was because the land is very unimproved grassland and so I avoided measuring height where there were big grassy clumps or other irregularities underfoot.  

 

So here are those figures:

 

Distance CM	Height CM
140	15
330	30
510	39
750	45
1280	60
1520	60
1790	85
2020	97
2270	110
2530	125
2660	129
2820	132
2930	137
3130	137
3370	141
3650	137
3960	138
4000	145
4120	149
4290	147
4510	142

 

 

Huge thanks 

 

How wide's the plot?

[Oxbow16]

18 minutes ago, SteamyTea said:

What like this

 

Yes!!!  Well, almost....  You'll have to forgive me if I gave the data wrong, or gave it in the wrong way  It's been a very long day and my mind's a bit frazzled!  

 

The land slopes downhill, so the graph is correct other than that it should start high and end low...  Is that possible?  

 

Sorry for all the confusion and thanks for the great help.

[Oxbow16]

5 minutes ago, Onoff said:

 

How wide's the plot?

 

It varies...  There are no straight lines here!

[SteamyTea]

You can reverse axis in Excel

Though I suspect this is not what you meant.

 

[Oxbow16]

6 minutes ago, SteamyTea said:

You can reverse axis in Excel

Though I suspect this is not what you meant.

 

No, I'm afraid not. But I think I've got it...  Adding a minus to each height figure in the excel sheet does what I'm after...  Got there in the end thanks to you guys  

 

Edited October 22, 2020 by Oxbow16

[SteamyTea]

5 minutes ago, Oxbow16 said:

It varies...  There are no straight lines here!

How are you measuring.

The easy way to do it is to stick in some stakes so that they are the same distance above the ground, they use a leveller to measure the height of each stake.

You need to do this on a grid as mentioned earlier. 

 

You can make your own leveller with a hosepipe, bit of clear pipe and a tape measure.

Start with the highest point and work downhill.

[Oxbow16]

What I did was quite crude tbh, and not particularly accurate either I'm sure.  But close enough for now.  I used string and started it just above ground level then put in two stakes along the length of land.  I attached the string to them, keeping it as tight as possible.  I'm guessing there must have been a little bit of bow to the string, but none that I could see when looking down the line so nothing major.  I used a spirit level to level the string, and then a tape measure to measure then height at the various points....  

 

[Oxbow16]

The finished article:  

 

 

Drainage Field Gradient Calcs with Graph.xls

[Moonshine]

If you want more detailed terrain information your site may have freely available lidar data for it.

 

Below is some terrain maps I made for a members much larger site which has a quarry in it.

 

 

You can put sections though the 3D map.

For my own site I made a 3D surface of my existing site from the survey data. This has been really useful for working out areas and volumes of cut from the site.

[SteamyTea]

I was in the Middle of Lidl yesterday and they had a laser level for 25 quid.

[joe90]

My (indoor) laser was not good enough fir working out land levels over our site, so I did it at dusk (Nearly dark) which multiplied many times the distance it would cover!

[SteamyTea]

1 minute ago, joe90 said:

My (indoor) laser was not good enough fir working out land levels over our site, so I did it at dusk (Nearly dark) which multiplied many times the distance it would cover!

You had the flattest site in the whole of the West Country.  The curvature of the Earth is almost greater.

[joe90]

43 minutes ago, SteamyTea said:

You had the flattest site in the whole of the West Country.  The curvature of the Earth is almost greater.

which is why it was so difficult to work out where the drainage would go, over 1 acre I had a drop of 500mm in one corner.