topic Re: Create Quarter sections lines in Geoprocessing Questions

Create Quarter sections lines

CCWeedcontrol — Thu, 11 May 2017 16:55:55 GMT

I have polylines of the sections and monuments. I need to create quarter sections lines. I am not sure what is the best way to achieve this without connecting the lines manual. I am sure some one has come across this before. So if anyone can help me out that would be awesome. Pic 1 show what i have and pic.2 is what i am trying to achieve.

Re: Create Quarter sections lines

AbdullahAnter — Thu, 11 May 2017 17:54:49 GMT

You can use copy parallel in Editor toolbar as in the picture :

Just define the quarter distance and select the line/lines and copy parallel.

Re: Create Quarter sections lines

CCWeedcontrol — Thu, 11 May 2017 18:26:18 GMT

That would work if the sections line where equal distance but they are not. I need to be able to snap point to point to create the quarter lines.

Re: Create Quarter sections lines

AbdullahAnter — Thu, 11 May 2017 19:08:18 GMT

in your picture I see it is equal distance, so I answered with copy parallel

Re: Create Quarter sections lines

DanPatterson_Retired — Thu, 11 May 2017 19:46:00 GMT

Do you have 10's, 100's or 1000's to do?

Re: Create Quarter sections lines

CCWeedcontrol — Thu, 11 May 2017 20:47:02 GMT

They look like equal distance but they are not but some might be. The county is odd shape and we have government lots so those are not a full section.

Re: Create Quarter sections lines

CCWeedcontrol — Thu, 11 May 2017 20:48:35 GMT

Dan, we have 654 sections.

Re: Create Quarter sections lines

DanPatterson_Retired — Thu, 11 May 2017 20:52:53 GMT

hmmm there is probably nothing in the point table that would enable you to identify which points belong to which quarter section. That might be useful for a connecting the dots approach

Re: Create Quarter sections lines

ChrisDonohue__GISP — Thu, 11 May 2017 21:19:01 GMT

Point of clarification - if I understand correctly, you have all the lines depicted in the first example, but need to cull them down to only the quarter section ones (so a subset) - is that correct? If that is the case, are the lines already attributed so you know which ones are the section lines (so there is a basis to then do the quarter-sections)?

Also, points are shown in the examples. Are the points attributed in any way that would help define which lines are section lines and which ones are quarter-sections? I ask as one way to do this might be to build the lines from the points using Points to Lines, but before doing so the points will need attributes that allow the correct assembly.

Points To Line—Help | ArcGIS for Desktop

Another question - are the lines all roughly North-South and East-West, or are some of them in other orientations (like NW-SE)? If they are all North-South and East-West, one may be able use their increasing X or Y values to help in differentiating them.

Chris Donohue, GISP

Re: Create Quarter sections lines

CCWeedcontrol — Thu, 11 May 2017 21:48:55 GMT

In the attribute table there is a x, y coordinate and 'Corner type'.

See attached pic of the attribute table.

Re: Create Quarter sections lines

CCWeedcontrol — Thu, 11 May 2017 22:00:58 GMT

I could also make the section line boundary ( i have those already, which is why i am needing the quarter lines) but if i can come up with a process to connect all points, sections points and quarter points that would work fine.

There is some attribute data see the pic i attached.

I did try the 'Points to line' with no luck well i did get a lot of lines but not what i was looking for. ha ha.

All lines only run north-south and eas-west.

Re: Create Quarter sections lines

ChrisRingo — Thu, 11 May 2017 23:27:38 GMT

You could write some code to go through the section centers (attributed as "CNT"?) one at a time. You should be able to pick out the the four closest quarter section corners ("QRT" in the attribute table?) using a selection distance of a bit more than half the average quarter section width of 1320 ft. Then you can use the coordinates in the attribute table to connect the center point with each of the four quarter-section corner points and you'd have your four remaining quarter section lines. I assume the relevant points are attributed as in the picture below?

Re: Create Quarter sections lines

CCWeedcontrol — Fri, 12 May 2017 16:12:08 GMT

I was hopping there was a tool that would do that since my python is not very good when it comes to something like this. I was hopping maybe someone had already done or figured out how to do something like this but i can't image i am the only one that has faced this issue, but may i am. Any help on how to accomplish this would be awesome.

Thanks.

Re: Create Quarter sections lines

AbdullahAnter — Fri, 12 May 2017 16:48:01 GMT

CC Weedcontrol ,if your quarter lines align from north to south and from west to east, there is a solution for your issue.

the points are align horizontal and vertical .and that is the clue

the solution is :

Frist : it is attribute task . you will add x and y coordinates field Add XY Coordinates—Help | ArcGIS Desktop

so you can classify each align points into classes , you will define the tolerance and group each align points horizontal into class and vertical points into class( the point has two classes one for vertical and other for horizontal)

Second :you will use Sort Tool Sort—Help | ArcGIS Desktop and you will add two fields for sort ( first horizontal class field , second x field)

and use Sort tool again for vertical and y fields.

Third : now you can get your quarter lines if you use Point To Line Tool Points To Line—Help | ArcGIS Desktop and use ID field of sort in this tool. And class field for line field in this tool.

I hope my answer be clear.

Re: Create Quarter sections lines

ChrisDonohue__GISP — Fri, 12 May 2017 18:45:44 GMT

Abdullah Anter has an good approach. However, check the output carefully, as unfortunately there will likely be issues if all your points are not all aligned exactly North/South and East/West. If they are not aligned exactly, some of the resulting lines will be "backtracking" and require some cleanup. Still, this is a good start that may resolve most of your lines (and probably be easier than drawing all the lines manually).

For example, note that the Y value for the point circled in red is slightly higher than the Y values for the points on either side. When the line is drawn automatically, it bypasses this point, then backtracks later to it.

Chris Donohue, GISP

Re: Create Quarter sections lines

ChrisDonohue__GISP — Fri, 12 May 2017 19:14:10 GMT

If the data is not perfectly North/South and East/West, an approach that would work that builds on what Abdullah Anter suggested would be to create a North/South and East West exact grid that covers the extent of your points by using Grid Index Features (geoprocessing tool), then derive the Sort Order for that Grid. Next, Spatial Join (geoprocessing tool) the grid to your actual points (so the sort order gets transferred over). Then you can run Abdullah's suggestion based on the exact grid sort order fields so the lines are drawn in the correct sequence (as opposed to the real points sort order, which can lead to backtracks).

Grid Index Features—Help | ArcGIS for Desktop Geoprocessing Tool

Spatial Join—Help | ArcGIS for Desktop Spatial Join Geoprocessing Tool. For the "Match Option" setting, use "Have their Center in"

Chris Donohue, GISP

Re: Create Quarter sections lines

ChrisRingo — Fri, 12 May 2017 19:17:08 GMT

I've attached a tool that you can use to create the interior quarter-section lines as I described in my post. In the zip there's a toolbox/script together a sample sections layer, a sample point layer, and mxd. It's a fairly simple script without much error-checking, but the workflow would be the following:

1) Run the script using your point layer as input; it will produce a text file of the interior quarter-section line segments as output. There's a distance parameter that I've defaulted to 1000 that you may need to adjust - the distance units are the same as your input point FC. It should be a bit larger than a typical side of a quarter-section (2640 feet, so I set the default to 1000 because the projection of my input point file had meters as the distance unit). The point of the parameter is that it needs to be big enough to select only the four quarter-section points closest to the section center, and no more. If you have sections that are really wonky, it may not work very well..

2) To convert the coordinates in the output text file to a FC, use the "XY to Line" tool (Data management/Features) - make sure to set the projection to that of your input point FC. The x- and y- coordinate fields to use should be obvious...

3) Merge these lines into your section lines (which you said you already had), and you'll have your quarter-sections.

Let me know if you need any clarification!

Chris

Re: Create Quarter sections lines

AbdullahAnter — Fri, 12 May 2017 19:41:17 GMT

maybe my suggest is not clear, but I said we will make classes the is for group each line.

you will define the tolerance and group each align points horizontal into class and vertical points into class( the point has two classes one for vertical and other for horizontal)

the correct is you will define the tolerance and group each align points horizontal into classes and vertical points into classes( ech point has two classes one for vertical and other for horizontal)

1and I said that we will use sort twice one for horizontal and one for vertical.

and use Sort tool again for vertical and y fields.

so we will use point to line twice either one for vertical and other for horizontal. And by using classes that I mentioned in point to line the line will never draws as your picture , Chris

Re: Create Quarter sections lines

DanPatterson_Retired — Fri, 12 May 2017 19:43:21 GMT

I suspect you have completed this manually by now?

Re: Create Quarter sections lines

ColinMurray — Mon, 15 May 2017 14:20:22 GMT

I also have wanted to do this but cutting quarters into LSDs. So same concept just smaller squares.

I have not found a tool that does this. The parcel fabric tools allow one to do this but only manually with many steps. I require an automated approach since there are many thousands of quarter sections to split up.

The approach I was working on but have not completed was to create an iterative model that would:

1. Select a quarter section polygon.

2. Convert to four polylines of the quarter section outline.

3. Create mid-points for all four lines.

4. Create polylines from these mid-points so that two lines half the quarter section east-west and north-south.

5. Cut the quarter section with these polylines.

6. Label the new LSDs.

Repeat thousands of times.

The problem, besides running out of time, was that I couldn't sort the mid-points to ID which one's were east, west, north, south to make the bisecting polylines. But it seemed like this would work based on a few tests.