Geology 210 – Lab #6

Introduction: Soil maps are invaluable tools for determining on a rather fine scale the relationships among such factors as parent material, elevation, slope, and weathering processes. In addition, soil map data is usually applicable to a wide range of practical concerns, including agriculture (obviously), construction and other land use considerations. This week we will return to the Madison-Bouckville area to explore the relationship between local soil types and surface geological processes and potential uses of different soil map units.

This lab will also require development of additional skills in ArcView, including the conversion of Arc Export files, converting map co-ordinates, and clipping shapefiles to more manageable size. The goal of the lab is to produce maps that illustrate the distribution of soils that are appropriate for a particular land use.

Map and data files: The Arc Export file that contains the Madison County soil map is located in the folder labeled "053soa" in the Lab #6 folder on the network. Since this the file is large, you will need to copy the folder to the desktop on your workstation. This file was downloaded from the CUGIR site (see lab #2). Do not copy the folder to your Zip disk, since it will likely exceed the capacity of the Zip. You will also need (copy to your zip) the basemap file, the Munnsville 7.5’ Quad .tif, and the Finger Lakes surficial geology coverage shape file. These are the same files we used in lab #5.

Use Import 71 to Convert the Soils Coverage to an ArcView shapefile: Select the Programs item on the Start menu, and navigate to the Import 71 icon under ESRI >ArcView GIS 3.2. In the dialogue box, navigate to the desktop folder and the file name ‘053soa’ using the browse button next to the Export Filename input area. Navigate to the same folder for Output Data Source, but enter a file name for the output file (e.g. madsoil). Select Ok, and the export utility will run for a couple of minutes. A shapefile with the name you input (e.g. madsoil) will be generated in the folder. Click open the folder to make sure the file is there.

Open the soils coverage in ArcView: Open the file that you have just imported (e.g. madsoil) as a theme in ArcView. Note that this will take some time, since this coverage is very detailed. You will note that the initial coordinate system is decimal degrees; use the View>Properties>Projection menu to select UTM 1983 under Category and zone 18 under Type. This will change the map projection to UTM with corresponding assignment of map scale. You may also wish to add the Munnsville 7.5 Quad as an image theme at this time, and locate the area of interest that we examined in Lab #5.

Prepare a ‘clipping’ shapefile: Examine the topographic map to visualize the approximate area of coverage that includes the ‘basemap’ area we used in Lab #5. Select View>New Theme, polygon. Give the new theme an obvious name like ‘madclip’. Use the polygon tool to draw a rectangular shape that covers the area of interest. Select Stop Editing and save the file.

Clip the soils coverage to the area of interest: Under the File menu, select extensions and turn on the Geoprocessing extension. Return to the View with both the Madison County soil coverage (e.g. madsoil) and the clipping file (e.g. madclip) active, select the Geoprocessing Wizard under the View menu. The sequence of menu windows will allow you to clip the county-scale coverage to a new shape file that corresponds to the clipping file. Save the new, ‘clipped’ file with an appropriate name (e.g. clipsoil).

Examine the soil coverage on the topographic map base: Deselect (or delete) all themes except for the new soils coverage (e.g. clipsoil) and the Munnsville 7.5 Quad. Edit the legend of the soils coverage so that the individual map units are show as unique values. Use the identifier tool to determine the map units represented in the study area. Use the symbol key in the Madison County Soil Survey text to determine the soil map units and characteristics.

Assessment of Soil Map Series:

1. How are the soil series above related to the glacial depositional system you examined in Lab #5? How is the distribution of these soils controlled by the surfical geology?

2. Uncle Gilman has asked your advice with regard to developing a new sanitary landfill in the  Madison-Bouckville area. He has asked you to assess the siting of the landfill on Mardin Series and Palmyra Series soils.

a. Use the Madison County Soil map text to assess the qualities of the two soil series and likely suitability for locating a landfill.

b. Prepare maps that show the distribution of the two soil types on the topographic base maps.

c. Advise Uncle Gilman as to the suitability of the two soils types for a landfill, and the existence of appropriate sites within the area of interest.