Introductory Exercises for GIS Using ArcMap & ArcCatalog

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Under “GIS Data” select “Hydrography”This will show all of the state-wide options for hydrography data. For this project, we want the seventhentry in the list, “Hydrography- Line Features” from CT DEP in 1984.Data can be projected in many ways in GIS. One common way is to display all features on a flat surfacewith distorted distances (from “spreading out” a round object on a flat surface), using latitude andlongitude only to specify point locations. This is called a geographic coordinate system and MAGICprovides data in WGS 84, which is a widely used geographic coordinate system. For small geographicareas distances may not be very distorted, but this can become an issue at larger scales. Another way ofdisplaying data is to preserve distances or areas, thereby making the 2-dimensional display of the dataappear somewhat warped or distorted (but suitable for measurements). These are called projectedcoordinate systems, and MAGIC provides data in the Connecticut State Plane projection. A shapefile isa common method for storing vector data and is comprised of multiple inter-related files. Another(older) method of storing vector data is coverages; these are also comprised of multiple inter-relatedfiles.Here, we will be using projected coordinate systems (CT State Plane).Before downloading data, create a new folder somewhere on your computer to store all of yourGIS files, such as C:\GIS_exercises.Please note that for the most used types of GIS data, file paths with spaces work fine. However, somedata types (including one we will be using here) require that file paths contain no spaces. Please createyour new folder in a location without spaces (for example, don’t put it in “My Documents”). Click on the appropriate CT icon to save the Hydrography layer, which will be downloaded as azipped file named CT_Hydrography_1984.s24.ctdep.line.zip.2
Now scroll to the section labeled “Roads & Transportation” on the webpage and select theprojected shapefile for “Connecticut Roads-1984” from CT DEP in 1984 (9 th entry in this section).Download the zipped file named CT_Roads.1984.s24.ctdep.zip to your newly created GIS folder.Scroll up on the webpage to the section labeled “Boundaries” and select the projected version of“Connecticut Towns (County Subdivisions) - polygon features” from CT DEP in 1984 (the 5 thentry from the bottom of this section). Be sure to select the polygon version. Download thezipped file named CT_TOWNS.1984.s24.ctdep.poly.zip to your newly created GIS folder.For this project you will be working with data from the town of Middlefield.Navigate back to the GIS Cyberinfrastructure Homepage:http://web2.uconn.edu/cyberinfra/module1/outline.html and download soils data “Data: MiddlefieldSoils”. Save the zipped folder to your data folder.Finally, download the quadrangle sheet (called a DRG) for the town of Middlefield from the coursewebsite (“Data: DRG”). This is an image (pixel-based) files with a .tif extension. Save the zippedfolder to your data folder.The Digital Raster Graphic (DRG) is a raster image, georeferenced to the UTM grid, of a scannedtopographic map minus the map collar information. These are created by the United States GeologicalSurvey (USGS). When you view these in ArcMap against the shapefiles you downloaded you will seethat they are useful as a source or background layer. For example, they can be used to perform qualityand accuracy tests on other digital files (assuming they are in the same projections!).Be aware that while this is a projected coordinate system dataset, it is in NAD 27 CT State Plane,which is different from the other layers we downloaded (those are in NAD 83 CT State Plane orWGS 84). We will come back to this difference during the map manipulations.These image files are large and therefore take a bit of time to download. While you are waiting,ensure that all of your downloaded files are in your GIS folder. If they automatically downloadedto a location other than your GIS folder, move them to your GIS folder now.Notice that the downloaded files have a .zip extension. This means that they are in a zipped orcompressed format. The next step is to unzip them, which will create ArcGIS shapefiles (.shp) or rasterfiles (such as the DRG which is .tif).3
Page 1: Introductory Exercises for GIS Usin
Page 5 and 6: Using ArcCatalogArcGIS shapefiles c
Page 7 and 8: Click “Add”, then “OK, then
Page 9 and 10: Navigate to the correct directory a
Page 11 and 12: Notice that ArcMap asks whether you
Page 13 and 14: In the toolbox window, select “Co
Page 15 and 16: There are several lakes found throu
Page 17 and 18: Click on the edge of Beseck Lake in
Page 19 and 20: Part II: Locating Prime Farmland in
Page 21 and 22: Prime Farmland Soils Prime Farmlan
Page 23 and 24: You have now located and effectivel
Page 25 and 26: Choose Aggregated Farmland and Buff
Page 27 and 28: You have now identified the most su
Page 29: Each element can be edited individu

Introductory Exercises for GIS Using ArcMap & ArcCatalog

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