GIS II Project ~ Phase 1

Introduction:

                Hydraulic fracturing, or “Sand Fracking,” is one of many methods by which the energy industry in the United States has been expanding its access to fossil fuels over the past two decades.  The process can be simplified as blasting a rock formation in order to knock loose trapped petroleum or natural gas.  An energy company drills a hole to the rock and then pumps fracturing fluid to the rock through a metal pipe with enough pressure to split the rock along a pressure gradient.  This fluid could be any of a number of materials: gel, foam and detergent could all be included in a mixture.  Along with the fracking fluid is a material called a proppant, which is small grains such as sand or ceramics suspended in a fluid solution.  This is designed to keep the fractures developed by the fluid open, by lodging particles in the small cracks opened up in the rock this material “props” the rock open when the fluid is gone.  If this didn’t happen, the fissures opened by fracking could close under the pressure of the earth!  In Wisconsin, the procurement of this proppant is a rapidly growing industry.  The state happens to be blessed, or cursed, with extremely accessible and pure silica sands which are used as proppant by energy companies performing fracking around the world.

Over the course of this semester, our geography class will step through the process of a land suitability/risk analysis of Wisconsin land for the development of sand mines in order to both expand our technical skills and examine the relationships that this industry has on the local landscape.  Today’s post is the first in this process.

Today’s goal is fairly straightforward: we are going to download geospatial data from various sources and import it into a Geospatial Information System.  This is the preliminary step in in our analysis where we are simply going to prepare data on land cover, railroads, soils, elevation, and cropland.  Once finished, we have all of this information projected into the same coordinate system and compiled in a single geodatabase.

Methods:

                The first task is to download the data that will be used for this project:

                From       Trempealeau County – we will download a land records geodatabase
                                National Atlas – railroads
                                USGS – digital elevation model
                                USDA – cropland data and a drainage index
                                NRCS SSURGO – soil data

                All of this data is in fact free to the public.  Anyone with internet access can use the information that will be used in this task.  Before the data is useable, a few things need to be changed.  The elevation data came in two separate topographic files, which need to be mosaicked together (using the mosaic tool in ArcMap, then mosaic to new raster).  The SSURGO data was downloaded as one database which contained only tables that referenced a half dozen georelational shape files; when importing to my personal geodatabase the shapefile required a component table to work.

 After this was accomplished, a new personal geodatabase was developed to house the data.  The soil feature class was combined into the same table as the drainage index, in order to keep organized and preserve data space and integrity (join tool).  The new soils/drainage information was stored with the data downloaded from Trempealeau County in a feature dataset.  Finally, all of this data was projected into UTM zone 15N, selected because of this exercise’s focus on western Wisconsin which is entirely within this UTM zone.

Results:

                As of yet, most of what has been accomplished is basic data management.  There is not much to see here really, but here are four images of Trempealeau County with their features titled.  They are missing a number of essential map elements, but hopefully they can convey a sense of what is being worked with on a statewide basis.