Data Gathering

Goals and Objectives: The goal of this lab was to download data from different sources on the web and to use this data in ArcGIS for creating a geodatabase. Also we learned more about using the Python Script which we used in projecting the data. The data we had to collect was for Trempealeau County, WI. Frac sand mining is a hot topic in this county, so I downloaded data that would help show how the mining is effecting the environment surrounding the mining sites.

General Methods: To obtain this data I went on five different websites that had information on the elevation, crop cover, land cover, railroad network, and the geodatabase for Trempealeau County, WI. The data downloaded off the site was delivered as a .zip file. I needed to extract the zip files to my working folder in order to view them properly. The websites that were used were the US Department of Transportation, the USGS National Map Viewer, the USDA Geospatial Data Gateway, the Trempealeau County Land Records, and the USDA NRCS Web Soil Survey. The links to the websites can be found below this paragraph.

Links

US Department of Transportation- http://www.rita.dot.gov/bts/sites/rita.dot.gov.bts/files/publications/national_transportation_atlas_database/2014/polyline

USGS National Map Viewer- http://nationalmap.gov/viewer.html

USDA Geospatial Data Gateway- http://datagateway.nrcs.usda.gov/

Trempealeau County Land Records- http://www.tremplocounty.com/landrecords/

 

 

USDA NRCS Web Soil Survey- http://websoilsurvey.sc.egov.usda.gov/App/HomePage.htm

 

 

 

Map Layers:

 

Cropland Cover from NASS raster

Land Cover from NLCD raster

Elevation from DEM raster




 Data Accuracy:

 

 

 

Conclusion: Some datasets are easier to find than others. Sometimes you can't find them at all and it makes the process more difficult for people who want to know if the data they are using is legitimate. This data could throw off the project and lead to many errors along the way. More websites need to start completing their metadata so that others can count on them as being a reliable source.  

Python Scripts

Python Script is a from of computer code that can be used to translate commands onto ArcGIS. It can be difficult to learn, but it is another language that can be useful in working with GIS. With it you can buffer, erase, and even intersect just by writing a simple script. In this instance, for Ex.5, I used Python to project, clip, and put different rasters into a geodatabase. The geodatabase is for Trempealeau Country and the purpose for the whole project is to figure out how sand mining in that area is effecting the environment. The letters in green tell the steps and the rows of words below them are the actual commands.

 

 

LAB 7

 

 

For this script we needed to take all the sand mines and separate the ones that don't have a rail line attached to the mine. I had to set up variables and a couple SQLs to help create a new feature layer. Using the script I was able to create a feature layer that shows the mines with no rail lines. Some problems I ran into were the silly errors like misspelling words or not capitalizing certain letters. After I fixed these errors the script ran fine. I went into ArcMap to make sure the layer worked and it did perfectly. The number of mines I had was 41 mines.

 

 

 

 

 

 

 

Lab 8

 

 





 

 

 

 

 

This script takes in all of the risk models created in ArcMap and creates a weighted risk model. The figure below shows the completed script when is done running.