Tutorial ch. 12, 13, and 14
March 3, 2008
Ch. 12 Analyzing spatial data
Most of the problems you solve with GIS involve comparing spatial relationships among features–in one layer or in different layers–and drawing conclusions. Problem solving in GIS is called spatial analysis, and it can include everything from measuring the distance between points to modeling the behavior of ecosystems.
In this chapter you buffer features using the buffer tool, in ArcToobox and then overlaying data using what was previously buffered. Then you calculate attribute values from the buffered and overlayed data.
Ch. 13 Projecting data in ArcMap
Locations on the earth’s surface are defined with reference to lines of latitude and longitude. Latitude lines, or parallels, run parallel to the equator and measure how far north or south you are of the equator. Longitude lines, or meridians, run from pole to pole and measure how far east or west you are of the prime meridian.
In the first exercise you project data on the fly. First you have to choose the US equal albers conic and apply it to the lower 48 map, alask map and hawaii map. Then you separately apply the alaska equal albers conic grid system and then the hawaii equal albers conic grid system and each will appear as they would on the map, even though the alaska and hawaii are zoomed in and placed differently.
In 13b you define a projection using the define projection tool in ArcToolbox.
Ch. 14 Building Geodatabases
Spatial data comes in a variety of formats that can be managed in ArcCatalog and added as layers to ArcMap. Many of these features, including shapefiles, coverages, CAD files, and geodatabases, organize spatial data into feature classes. A feature class is a group of points, lines, or polygons representing geographic objects of the same kind, like countries or rivers.
In 14a you create a personal geodatabase in the ArcCatalog by navigating to chapter 14, MyData and clicking on Personal Geodatabases. In 14b, you convert data into your geodatabases using ArcGIS, not ArcCatalog. In 14c you add two fields to a feature class you created in the previous exercies.
