What if I want to map land parcels?
My local volunteer fire department purchased a copy of Depiction asked me to help them with a project. The fire chief had several things he wanted to do with the software but the first one was to create a map of all of the parcels in the district and then add to it the ownership information. He had received two files from the local county GIS department: a shape file of all of the parcel boundaries and a database file of the ownership information from the assessor.
The challenge was to get the shape file data loaded and then geo-code the address data.
The first challenge was to get the shape file loaded. The main issue here was because of the shape of the fire district in order to get the entire district in one story also meant getting non-district territory included. This wouldn’t have been a problem but the file from the county was of the entire county and not just the district, so when the shape file was loaded it included the shapes for the non-district territory as well. Unfortunately this added about 2000 more shapes to the file which of course would have had an performance impact. So I ended up cutting the district in half and having two files. I still had non-district shapes but an acceptable number.
So at this point I had the parcel boundaries loaded and went to load the data files. I extracted the district parcels from an Access data file to an excel spreadsheet. The situs address on each record was broken into several fields; street no, direction, name; city, state, zip. I used the concatenate command in excel to join the fields together in a field called “Location” which is one of the field names that Depiction recognizes for geo-coding and I had to make sure that none of the other field headers included one of the valid fields such as “address”. After doing this and reviewing the file I realized that many parcels didn’t have addresses. In addition to that this district is in a rural area with a combination of small lots and multi-acre parcels. The geo-coding algorithm works pretty in good in urban areas but not so good in rural areas. It gets you in the neighborhood but that is about it.
So my quandary was how to deal with the parcels with no addresses and how to figure out where the ones with addresses actually went on the map. In looking at the tax account # I realized it was made up of Township, Range, Section and then an “XY” coordinate. I remembered that the assessor parcel maps usually had the XY coordinate on the lot and the TRS info was also on the map. So I went to the assessor’s online site and found the maps. I took a screen shot of each one and then cropped it down to the area I wanted and then converted the BMP files to JPG to save space. Then I loaded each map into my Depiction and geo-aligned it with the parcel shapes. (Update: after further review I discovered the quality of image from the screen shots wasn’t that good and many of the numbers were illegible. Instead I downloaded the native PDF files from the assessor and then used a program to convert them to jpegs.)
Next I separated my data file into North and South sections to match my Depiction Map files which I could do by the Section Township Range info in each record. Then I sorted each file by address. The parcels with a “0” address sorted to the top. I then created a new worksheet in excel and cut and pasted the “0” address parcel info to the new worksheet.
Next I took a known valid address in my map area and inputted it in to the “Location” field of the first record in my spreadsheet. I then copied that cell across the other records. This incremented the address number by one. So now I had a file with valid addresses. I did this because I wasn’t sure what depiction would do with an invalid address. Next I saved the file as a CSV file and then resaved the original file as an XLS file so I wouldn’t mess up my data.
Then I went into my depiction. I was going to use the “HOME” element for my parcels with houses on them but I wanted a different icon for vacant land. So I created a “HOME” element then I right clicked on it and edited it. I changed the name to Vacant Land and I changed the icon to the shape file icon because I didn’t have anything better. Then I saved it to my library and at which time I had a new element called vacant land.
Then I chose the add menu item and File underneath that and then browsed to my CSV file and chose it and the selected vacant land as the element type and pressed the add button and a few minutes later my vacant land icons appeared in a row.
Next I created a CSV file of the worksheet of the parcels with addresses and loaded them. As I mentioned earlier the icons appeared in the general area but not in the exact location.
In both cases above when the program finished loading it came up with the edit screen for that element type. Before I closed it I did the following:
1. Changed the property to allow dragging
2. Set the hover text to the fields I wanted to display.
3. Changed the ICON size to Tiny because there will be a lot of icons on the screen.
So now I was ready to manually place each icon in the right location. In the hover text this included the tax account number which I had reformatted to make it easier to read. So using a revealer I displayed the assessor map for the area I was working on moused over an ICON saw the account # and then looked for that XY coordinate on the assessor map and when I found it I moved the icon to that parcel. I am still working on this process to move each icon.
So when I checked in with the Chief to discuss this we realized some of the drawbacks of this process. One was that it would be easy for someone to accidentally or on purpose move an icon. Also it wouldn’t be easy to make a bunch of changes in the data base and reload it because you would have to relocate all of the icons which a fairly time consuming. So what we are thinking about doing is once we have located all of the parcels to mouse over each one and transfer the Lat Long info back to the spreadsheet. Once we have done that then we could delete all of the parcel data and reload anytime. Now the Chief says once we have located all the parcels it would be nice to locate all of the propane tanks on each parcel. Another project for another day. I will keep you all posted with how we are progressing.
Another update. A new requirement came up and that was to identify properties that paid DNR tax for forest fire protection. A new file was received from the Assessor with this info. Since I was redoing things decided to start over. Broke the district into 3 sections to eliminate extra shape files. When I broke up the district I did it on Section boundaries so that it would be easier to group the assessor records for each section. Broke the assessor data into 4 parts for each of the 3 areas. Improved W FF, Improved WO FF, Vacant W FF and Vacant WO FF. Made 4 new icons. I basically took two existing icons and changed their colors to represent homes and vacant land with and without FF.