Gathering Data

Goals and Objectives:

The main purpose of this exercise was to gain practice in gathering online data. This data is needed for the semester long project regarding frac sand mining in Trempealeau County. This exercise also places importance on importing, joining, and projecting the data. Finally, the exercise allowed for experience in creating a geodatabase for all of the data to be stored.

General Methods:
To begin downloading data, I first created a new folder in my Q-drive labeled Ex_5. This allowed for better organization of all of the data. The data gathered in this exercise came from:
                            
                             US Department of Transportation
                             US Geological Survey- National Map Viewer
                             US Department of Agriculture
                             USDA NRCS Soil Survey
                             Trempealeau County Land Records 

 Each of the datasets were downloaded to a temporary folder in the department's Q-drive because of the large size of the unzipped datasets. From the temporary folder, the data was extracted to a working sub-folder within the Ex_5 folder. The data downloaded was then projected, joined, and added to a geodatabase through Python Script. This process can be seen in the blog post titled "Python Coding". The following maps of relevant data were then created in ArcMap (Figure 1). 

Figure 1: these four maps consist of relevant raster data for Trempealeau County, WI. Data was collected from various online sources. These sources can be seen below in "Sources".

Data Accuracy:
It is important when gathering data off of the internet to be confident in the data accuracy. This can be determined by looking at the metadata. Metadata should be found in the properties of every dataset and shows how accurate and reliable the data is. Important information in the metadata include its scale, effective resolution, minimum mapping unit, planimetric coordinate accuracy, lineage, temporal accuracy, attribute accuracy. This information can be seen in Table 1.


Conclusions:
The above data shows a wide array of accuracy and extents. It is important to know the type and accuracy of the information for this project because of the reliance on accurate features. In order to create accurate maps and analysis of frac sand mines and their impact on the Trempealeau County the data collected and used must be correctly displayed.



Sources:
US Department of Transportation-
http://www.rita.dot.gov/bts/sites/rita.dot.gov.bts/files/publications/national_transportation_atlas_database/index.html

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

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