Homework Assignment 3. Joins Overview In this scenario, you are interested in knowing more about robberies around parks. You visited all of the parks in Acme City to collect more data about the city's parks, but now you need to join the data you collected about parks to the parks feature class. Next, you will count up the number of robberies in a series of street corner units to determine if high robbery street corners are located near parks. Overall, you will create a map showing different parks and their use of rules to control behavior and street corner robbery rates to determine if parks with or without rules posted are related to higher street robbery levels. Files Needed: 1) Crime_Mapping.aprx and the 2) Crime, 3) Neighborhoods, 4) Parks, 5) River, and 6) Streets, 7) Street_Corner_Units feature classes saved in the Acme_City.gdb as well as the 8) Parks_Site_Visit_Data.dbf file you can download from the homework assignment 3 page. Getting Started We are going to practice some skills we previously learned by starting this assignment from "scratch". 1. Open the ArcGIS Pro program on your computer 2. Load the Crime_Mapping.aprx file The Map and Homework 1 and 2 layouts within the Crime_Mapping project should open in ArcPro. Add a New Map 1. Click the Insert ribbon > 2. Under Project, Click New Map > 3. Select New Map A new Map window will be added to your project. It will receive a default name using Map and a number like 1 or 2 depending on how many maps you have previously added to your Project. 4. With the new Map window open, in the Contents window, click the new map's name once, and then once more to make the name editable 5. Rename the new map Map - Parks & Robberies Remove the base maps: 6. Right click World Topographic Map in the Contents window > Click Remove 7. Right click World Hillshade in the Contents window > Click Remove 19 Add the following course data to the Map. 8. Parks, River, Street_Corner_Units, and Streets feature classes 9. Use the same process to add the Robbery layer from the C:\CrimeMapping\Data\MyOutput folder Change Map Symbology Change the default symbology of each feature class. You can do that by right-clicking on a layer and clicking symbology. 1. Change Robbery to Circle 3 & Size = "5 pt" 2. Change Streets to a Black line color 3. Change River to the scheme 2 "Water (area)" option 4. Changes Parks to Leaf Green 5. Ignore the Street_Corner_Units for now Re-Arrange the Layer Drawing Order Rearrange the drawing from top to bottom to be: 1. Robbery 2. Streets 3. Parks 4. Street Corner Units 5. River Table Join (Join by Attributes): Joining Park Site Visit Data Now we are going to join the data about parks we collected on our site visits to the Parks layer. To add the Parks site visit data: 1. On the Map ribbon, under Layer, Click Add Data > 2. Data > 3. Navigate to the folder where you saved the Parks_Site_Visit_Data.dbf file > 4. Click the Parks_Site_Visit_Data.dbf file > 5. Click OK The site visit data for the parks will be added to your Contents pane under "Standalone Tables". We need to join the park site visit data to the Parks feature class. 20 20 ? X 1. Right-click Parks > Joins and relates > Add Join The Join Data dialog box will open. 2. In Input Table select Parks 3. In Input Join Field select NAME 4. In Join Table select Parks_Site_Visit_Data 5. In Join Table Field select NAME 6. Tick Keep All Target Features 7. Click OK Now have a look at the results of your join. 1. Right-click on the Parks layer > Click Attribute Table Scroll to the right Add Join Input Table Parks Input Join Field NAME Join Table Parks Site Visit Data Join Table Field NAME Keep All Target Features Index Joined Fields Validate Join 國 Add Join Remove Join Remove All Joins Add Spatial Join Add Relate Remove Relate Remove All Relates All of the data collected about parks should show up, like below, in the Park layer's attribute table. Parks - CrimeMapping - ArcGIS Pro Parks X < Field: Add Calculate Selection: Select By Attributes Zoom To Switch Clear Delete Copy OBJECTID 1* Shape OBJECTID NAME 1 1 Polygon 3509 Habsland Park Shape_Length Shape_Area OID OBJECTID NAME 4139.325154 811500.447424 0 3509 Habsland Park Hours Rules Yes Yes 2 2 Polygon 4145 Avon Garden 2919.851542 340076.643325 1 3 3 Polygon 4 4 Polygon 5 5 Polygon 6 6 Polygon 7 7 Polygon 2082 DolphinPark 5763 Old City Woods 7051 Bell View Park 4287 Rhineland Park 5444 Hidden Park 7955.383897 1033019.340843 2 4145 Avon Garden 2082 DolphinPark Yes Yes No No 7702.885712 3177193.520568 3 5763 Old City Woods Yes Yes 3357.401628 330220.649631 4 7051 Bell View Park No No 8 8 Polygon 4491 Open Fields 2394.836324 318653.145445 5 4372.368342 848455.943374 6 1758.891437 183132.308939 7 4287 Rhineland Park No No 5444 Hidden Park Yes Yes 4491 Open Fields Yes Yes 9 9 Polygon 4493 Hopkins Park 825.235607 39460.223366 8 4493 Hopkins Park Yes Yes 10 10 Polygon 0 West Side Sports Com... 2907.510035 432875.454317 9 0 West Side Sports Com... No No 0 of 10 selected Filters: + + 100% OK Making a Table Join Permanent Table joins are temporary. You can make a Table Join permanent by exporting a feature class after you join a data table to it. 1. Right-click the Parks layer > Data > Export Features 2. Confirm a. Input Features: Parks b. Click the folder icon next to Output Feature Class: 3. Navigate to C:\CrimeMapping\Data\MyOutput > 21 4. Type Parks_with_data in Name: > 5. Confirm the far-right drop-down is set to Feature Classes (All Types) > 6. Click Save > 7. Click OK If you open the attribute table for the Parks_with_data layer, you will see the additional data we collected on bars. Point-in-Polygon Spatial Join: Joining Robberies to Street Corner Units Now you need to count up the number of robberies within each street corner. The Street Corner_Units feature class is a layer of street intersection centered Thiessen polygons. Thiessen polygons are a unique type of polygon commonly used in crime mapping. The Thiessens are drawn so that every point in a given polygon is closer to the centroid of that polygon than any other polygon's centroid. Centroid is just a fancy word for center. Since these Thiessen polygons were created using street corners as the centroid, any point (or crime event) in a polygon is closer that street corner than any other street corner. To count up all the robberies in the Thiessen polygons: 1. Click the Analysis ribbon> 2. Under Tools, scroll to the default 3. Click Summarize Within group > The Summarize Within dialog box will open. 4. In Input Polygons select Street_Corner_Units 5. In Input Summary Features select Robbery 6. In Output Features Class click the folder icon > 7. Navigate to C:\CrimeMapping\Data\Acme_City.gdb Note that this tool only outputs feature classes within geodatabases. 8. In Name type Street_Corner_Robbery_Counts 9. Confirm the far-right drop-down reads Feature Class (All Types) 10. Click Save Geoprocessing Summarize Within + Parameters Environments ? Input Polygons Street Corner Units Input Summary Features Robbery Output Feature Class Street Corner_Robbery_Counts Keep all input polygons Summary Fields Field Add shape summary attributes Group Field 11. Click Run (you can check your work with the dialog box to the right) Statistic Run 하 22 22 Creating a Map: Street Corner Robbery Counts & Park Rules Posting You can now use the Robbery counts to create a map that shows low to high robbery corners. You have two options here: 1) you can display a raw robbery count or 2) you can display a robbery rate. We'll focus on robbery rates in this exercise so you can learn some additional GIS skills, but feel free to compare the robbery count map to your robbery rate map on your own. First, let's look at the street robbery count variable. 1. Right-click the Street_Corner_Robbery_Counts layer > Click Attribute Table 2. Scroll to the right until you seen the field Count of Points 3. Right-click the field Count of Points > Click Sort Descending You can see the maximum street corner robbery count is 5. 4. Right-click the field Count of Points: 5. Click Statistics Two panels open. A graph showing the distribution of the Count of Points variable opens in the Attribute Table and descriptive statistics formatting options open as well. If you click on the bars in the histogram you will see the street corners with those respective crime counts are selected in the map. You can also get the number of street corners within each grouping by hovering the mouse over the bars. We can see the counts are mostly zeroes (n = 1,288) with some ones (n = 246), twos (n = 66), threes (n = 23), fours (n = 9), and a few fives (n = 3). Count Street Corner_Robbery_Counts - Distribution of Count of Points - CrimeMapping - ArcGIS Pro Street Corner_Robbery_Counts Street Corner_Robber...Count of Points X Filter: 曷: ☑ 1,200 1,000 800 600 400 200 Distribution of Count of Points Count of Points 23 ☐ -Mean: 0.30459