Methods
Data for this lab: ESRI street map USA (used for network dataset)
Routes for the frac sand transportation were calculated using a closest facilities network layer. This layer calculates the nearest facility (rail terminal) from the incident (sand mines). Once the routes were created, routes needed to be separated by county in order to calculate the impact cost. The model below uses the clip tool to separate each county's routes from the closest facilities layer.
The model is using the closest facility layer as the input feature and each individual county as the clipping feature. This produces a line feature for each county. By using the measuring tool, the mileage of each county's routes can be calculated for the impact cost analysis.
Route Length by County
Barron County - 16.778 mi
Chippewa County - 28.082 mi
Eau Claire County - 21.792 mi
Trempealeau County - 25.123 mi
Jackson County - 5.483 mi
The lab has students assume that each sand mine takes 50 trips per year to the rail terminal and then back to the mine. Also, the hypothetical costs per truck mile is assumed to be 2.2 cents.
The equation that I used to calculate impact cost can be found below.
Mileage x 100 x 2.2 / 100 = Impact Cost
Results
Impact Cost
Barron County - $36.91
Chippewa County - $61.78
Eau Claire County - $47.94
Trempealeau County - $55.27
Jackson County - $12.06
After conducting network analysis on the impact of frac sand transportation, Chippewa County is impacted the most. Even though Chippewa County has two sand mines which are located closest to the rail terminal, the sand mine located in Barron County is responsible for most of the transportation through Chippewa County. If the Barron County sand mine trucks are responsible for most of the impact cost of Chippewa County, should Barron County also be responsible for paying that impact cost? Would it be reasonable for the Barron County trucks to take alternating routes through Dunn County instead of only using Chippewa County roads? Eau Claire County has the third highest impact cost, and that county doesn't even contain a sand mine! Frac sand mining affects not only the environment, but also local government, the economy, and local roads.
