Module 1 - Basics of Data and Information

Learning objectives of Module 1

The primary objectives of Module 1 were to describe geographic data including the different types, such as place, time, and feature attributes, and the different types of attributes, such as nominal, ordinal, interval, ratio, and cyclic. Depending on the different types, tools used to describe these data will be more or less appropriate. There was discussion of the fundamental problems associated with representations of geographic data and ways to conceptualize such data. We gained a better understanding of what spatial analysis is and of the various strategies and tools involved therein.

Problem:

One strategy to work with geographic data includes spatial analysis. To explore the different spatial analysis tools available in ArcGIS, in this example, we examined data points pertaining to elevation mapping.

Analysis Procedure:

Before the tools can be identified and used, they need to be loaded into the ArcMap document by turning on the Spatial Analyst extension. It is important to set the geoprocessing environment so the data processing results are stored in the proper place. With the data layer added for the elevation sample points, open and run the Inverse Distance Weighted tool.

Results:

For this exercise, the output was a map showing the area with the different interpolated elevations (Figure 1).

Figure 1. Interpolated elevations using the IDW tool in ArcMap. Green = low elevation, white = high elevation.

Application and Reflection:

Spatial analysis is a method by which we are able to link locations, attributes, and relationships in geographic data to allow us to extract information to address our research questions. Returning to the mushroom hunting project my daughters and I are working on (see Our Mushroom Hunting), I wanted to create a layer to visualize the contour regions in addition to the contour lines. Using the tabular contour data of the geo-referenced data acquired from http://data.nconemap.com/geoportal, I ran the Topo to Raster tool in ArcMap. The results of this analysis produced areas of 100-foot elevation increments for visualization as well as potential polygons for the purpose of identifying if and how mushroom distribution will be influenced by elevation in Eno River State Park.

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