GUS 0265: Applications in GIS Spring 2007

Lab 3: Vector and Raster Analysis

The purpose of this lab is to review basic vector and raster data handling and operations, as well as introduce raster point distance and density functions.

Objectives

This lab concerns environmental justice in New Jersey. Your objective for this lab is to analyze the spatial pattern of air pollution facilities with regards to the distribution of socioeconomic character and land use.

Your analysis should address the following general research questions:

  1. Is there a spatial relationship between the distribution of facilities and percent minority (defined here as either non-white or Hispanic[Hispanics can be of any race], population density, median owner-occupied housing value, and commercial/industrial/transportation land use?
  1. If a spatial relationship does exist between the location of facilities and any of these variables, what is the form of that relationship?

Data

The data for this project can be found in the directory S:/GUS_0265/lab_03

facilities a shapefile of facilities in New Jersey that release air pollution and are listed in the Environmental Protections Agency’s Aerometric Information Retrieval System (AIRS). The ‘Afsid’ field is the unique identifier for each facility.

tractsa shapefile of Census 2000 tract boundaries for New Jersey. The field ‘Areakey’ is the unique identifier for each tract.

tracts_dataa .dbf file with a few select Census 2000 data fields. The field ‘Areakey’ is the unique identifier for each tract. The field ‘Arealand’ is the land area of each tract in square meters.

Sf3A .pdf file that is the data dictionary for Census 2000 Summary File 3 data, including the data contained within tracts_data.dbf. You can use this file to find out the meaning of the field names in the tracts_data.dbf file.

nlcd_nja raster grid of land cover for New Jersey

new_jersey_readme.txtinformation on the New Jersey land cover data

new_jeresey_FGDC.txtmetadata for the New Jersey land cover data

Deliverables

Perform the following specific analyses:

  1. Spatial Coincidence. Classify the tracts into two groups: those that contain facilities and those that do not. For each tract group, calculate the percent minority,population density, and percent commercial/industrial/transportation land use. Report the summarized socioeconomic and land cover variables for each tract group in a table.
  1. Distance to Nearest Facility. Use a raster spread (Euclidean distance) function to derive a grid of distance to the nearest facility. For each tract calculate the mean distance for all grid cells within the tract. Classify the tracts into five exclusive groups based on a quantile classification scheme of mean distance to the nearest facility (i.e. each group will contain 20% of the tracts). For each tract group, calculate the percent minority,population density, and percent commercial/industrial/transportation land use. Create charts (column charts work well) expressing the values of the summarized socioeconomic and land cover variables for each tract group. You can use Excel to create the charts.
  1. Density of Facilities: Repeat the above step 2, except instead of focusing on the distance to the nearest facility, use a raster point density function to derive a grid of facility density, and for each tract calculate the mean density.For the density function, use a radius distance of 100 meters. As in step 2, report your results using charts.

You should turn in a 2-3 page report in the style detailed on the Lab Information web page ( Remember, the report must include the following sections:

  • Introduction: the purpose of the report; a statement of the problem.
  • Methods: a brief description of the data and the methods (operations) you used to do the analysis.
  • Results: a summary of the results
  • Conclusion: an interpretation of the results, an assessment of accuracy and sources of error in the analysis, as well as recommendation for further actions.

Note that the results section must include the table of the Spatial Coincidence analysis results, and charts for the Distance to Nearest Facility and Density of Facilities analyses.

Supplement your report with maps and diagrams reporting on the data and methods. Each table and figure should be on a separate page, labeled as table or figure 1, 2, 3, and so on, and referenced in the text appropriately. The tables and figures should reside at the end of the report in the order in which they are referenced in the text.

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