Friday, March 18, 2016

Data Interoperability, Data Sources and a continuation of Sand Mining Suitable in Western Wisconsin



 
Goals and Objectives: For this lab the objective was to become familiar with process of downloading data from different sources online. Then, once downloaded, understanding the organization, structure, and methods that must be undertaken to use the data in ArcGIS. These processes include importing, joining and projecting various data sets such that they all can be aggregated into a data set which can be displayed and analyzed. In the continued project of understanding sand mining impacts on Western Wisconsin we are going to particularly look at Trempealeau County, which again, has multiple frac sand mining sites, as well as a transportation infrastructure for transporting the sand.

 

General Methods: In order to begin to analyze impacts of sand mining, various data will be needed to realizes mining and transportations impact on the county. For the first set of data, we had to download the National Rail Network Data Set from the U.S. Department of Transportation. Next we had to download data for land cover from the U.S. Geological Survey's National Land Cover database.  From the USGS we took three sets of files;  a Land Cover Dataset, a Percent Developed Imperviousness data set and a 1/3 arc-second DEM data set for Trempealeau County. Next we downloaded data from the U.S. Department of Agriculture Geospatial Data Gateway, for cropland data in Trempealeau County. Next we downloaded data from the U.S. Department of Agriculture National Resource Conservation Service for SSURGO data, which is a digital soil survey developed by the USDA. The SSURGO data was in the form of an access database which had to be altered and aggregated so it could be useable. And Finally we downloaded data from the Trempealeau County Land Records Department for a geodatabse of the county.

 
Getting all of this data in a useable form was actually quite a challenging process. which involved merging tifs, clipping data, mosaicing rasters, and a in depth knowledge of the values and abilities of both the datasets and ArcGIS in order to keep the data intact and usable throughout the process of readying the data.

Sources of data used in this analysis:

 






 
Data Accuracy: For each of the different data sets that I have downloaded the following data measures were reported:
Data Source
Dataset
Scale
Effective Resolution
Minimum Mapping Unit
Planimetric Coordinate Accuracy
Lineage
Temporal Accuracy
Attribute Accuracy
U.S. Department of Transportation
 National Transportation Atlas Database (2015)
1:24,000 to 1:100,000 scale


None 
 None
"Continually Updated"
 
U.S Geological Survey
National Land Cover Database (2011)
 None
 None
 None
None
None 
 
 
U.S Geological Survey
1/3 arc-second DEM
 None
One arc second (~30 meters)
 None
 
 
20
 
U.S. Department of Agriculture 
Cropland Data layer by state
~1:100000
30 meters by 30 meters


None 
Data collected between 03/01/1997 and 09/14/2006

Trempealeau County Land Records
Trempealeau County file geodatabase
 None
 None
 None

 
"updated on regular basis"
 
U.S. Department of Agriculture Natural Resource Conservation Service
NRCS Web Soil Survey
0.736111111
 None
 None
 
 
9/17/2015
 
Fig 1. Table of Data Accuracy. Squares left blank indicate no information was found.






Fig 2. Map of Wisconsin with Specific not of Trempealeau County







Fig 3. Trempealeau County Land Cover

Fig 4. Trempealeau County Cropland. Note* Cropland with minimal values (10 counts or less) were not included


Fig 5. Trempealeau County Drainage risk index and Rail Lines.


Fig 6. The Elevation of Trempealeau County.





Fig 7. Trempealeau County Soil Drainage Risk Index. Very high soil run off risk is indicated by the darker





Conclusions: As you can see from the data table, most of the GIS data that was downloaded was missing key metadata that should be a standard in the GIS industry. I find the lack of accuracy or precession reported for any attribute data particularly to be odd, if the data is to be published in the purpose for analysis, that information is key for analysis by the scientific method. With out that information we don't know how much error or variability is in the models we are building, and that is a very troubling thing for finding answers to questions.

Looking at all the maps that were created, we see that the Frac sand mines are near developed areas, on crop or near cropland, on higher elevations that have a higher risk of soil runoff. All of these factors individual may or may not have drastic impacts on the surrounding area in the grand scheme of things, but it may not have actually occurred to anyone that these factors combined may have magnify potential negative effects of frac sand mining.




Friday, March 11, 2016

Python Scripts


Post # 2 (4/12/2016)


For the second Python Code we had to write we were attempting to automate a series of tools that would not only select fields based on SQL Query Statements, but create feature classes of those narrowed layers to select Frac Sand mines in Wisconsin that were not close to a rail network. This will be important because Frac Sand mines that are not close to rail networks will rely on roads to transport the sand to rail network locations, impacting the roadways and local infrastructure.


Python Script for selecting mine locations based on the mines proximity to rail networks in the state of Wisconsin.