Massachusetts Institute of Technology Department of Urban Studies and Planning 11.520: A Workshop on Geographic Information Systems 11.188: Urban Planning and Social Science Laboratory Lab Exercise 6: Vector Spatial Analysis Due: in Lab 7 In this exercise, you will perform several different types of spatial analysis using the TIGER files (cambtigr), census block group data (cambbgrp.shp), land use data (landuse85.shp), and various retail store locations for Cambridge. Preliminaries 1) Launch ArcMap and add the following layers in the directory M:\data. • M:\data\landuse85.shp Cambridge land use in 1999 per MassGIS • M:\data\cambbgrp.shp (not a coverage) U.S. Census 1990 block groups for Cambridge • M:\data\cambtigr (coverage) U.S. Census 1990 TIGER file for Cambridge • M:\data\cambridge_ice_cream.shp Ice cream stores in Cambridge • M:\data\cambridge_bookstores.shp Bookstores in Cambridge • M:\data\cambridge_record_stores.shp Record/CD/Tape stores in Cambridge The source for the cambridge_ice_cream.shp, cambridge_bookstores.shp, and cambridge_record_stores.shp layers is the http://www.bigyellow.com/ web site on November 1, 1999. The locations were downloaded from the web page, then geocoded in ArcMap. We'll be exploring address geocoding in a subsequent lab. Recall the usual preliminaries:• Since the datasets we'll be using are in Mass State Plane coordinates, select View > Data Frame Properties in the menu bar and set the map units to meters and the display units to miles. If you want, you can also change the name to something more informative than "Layers". 2) Go to the M:\data\chapter11 folder. You can find ArcGIS map document files, ex11a.mxd and ex11c.mxd and directories, "Data" and "MyData". Please copy all files and directories under the chapter11 folder and save them in your personal working space. Part 1: Point in Polygon Spatial Join and Cluster Analyses In this part of the lab, you will examine the demographic characteristics of the block groups in which various types of bookstores are located. The bookstore data are contained in the shape file called cambridge_bookstores.shp. ArcMap can do 'polygons to point' overlay operation using a spatial join. This time, we'll explicitly set up a spatial join between cambridge_bookstores.shp and cambbgrp.shpso that block group attributes can be added to bookstore table. Spatial join • Click the cambridge_bookstores layer from the data frame window. • Click the right mouse button to select joins and relates > join. Join Data window will come up. • Select "Join data from another layer based on spatial location" for "What do you want to join to this layer" option. • Choose cambbgrp.shp for a layer to join to this layer. • Check the "it falls inside" option • Specify the name (bookstore_bgrp.shp) of the new file and the location (your working directory) where it is stored. • Click "OK" The new shape file you just created (bookstore_bgrp.shp) will be added in your data frame. If you examine the attribute table for bookstore_bgrp.shp you should now see the attributes of cambridge_bookstores and cambbgrp.shp. The "Shape" columns aren't true attributes; they serve as placeholders that represent the geometry of layers that allow us to perform the spatial joins this way. Now we can make a thematic map of cambridge_bookstores.shp using the attributes of cambbgrp.shp. Open the layer property window of bookstore_bgrp.shp to make a "Graduated symbol" map using the "Med_hh_inc" field. You should end up with the bookstore locations sized by the median household income of the block group containingthem. To provide additional context for interpreting these locations, create a thematic map of land use using the landuse85.shp layer. This time you can name the file as "bookstore_lu99". Follow the same instructions as in the Explanatory Mapping portion of Lab 2, except this time ignore the directions regarding the layer sales89. Make the Cambridge TIGER file visible as well. • For the definition of the land use code, please check the Massgis (Massachusetts Geographic Information Systems) land use definition at http://www.state.ma.us/mgis/lus.htm Take a close look at the pattern of bookstores. Does anything look interesting? Write your observations as requested in the Question 1 of the assignment. Make a layout of your map and submit this as the answer for Question 2. For extra credit, or just for fun, redo the spatial join, this time tying the block groups to the ice cream stores and the record stores (this requires a spatial join for each of the store layers) and display them on the map too. Do the additional store locations help you to see a pattern? Part 2: Buffer Analysis In this part of the lab, you will analyze the demographics of the neighborhood around MIT's biological research facility on Ames Street. You will build on what you learned in the "Simple Buffering" part of Lab 3 to do a more elaborate analysis. Here, you will use ArcMap to calculate the number of children 5 years of age and under who live within half a mile of the facility. To begin, you will draw a half mile buffer around Ames Street. First you will select Ames Street from the cambtigr coverage and then draw a buffer only around that street. Select the cambtigr layer, then use the Selection > Select by Attributes... menu item to select the arcs where the "Fname" field is "Ames" and the "Ftype" field is "St". You may have trouble spotting the arcs you just selected; use the View > Zoom Data > Zoom To Selected Features menu item to help you find them. You should end up with three selected arcs. Now let's draw a 1/2 mile buffer around Ames Street. Use the Analysis Tools > Proximity>buffer (please see following figure) in toolbox to start the buffer tool. In the first step, make sure to buffer only the selected features of cambtigr. In the second step, specify a distance of 0.5 miles. Note that you must type the leading zero! In the third step, tell it to dissolve the barriers between the buffers by selecting "ALL" and to save the results in a new layer called amesbuf in your working directory. A new data layer called amesbuf will appear in your data Frame. Now move down the amesbuf layer so that cambtigr and the point layers display above the buffer. You should be able to clearly see the selected arcs in cambtigr at the center of the buffer.Number of Children within a Half Mile of Ames Street Since you are interested