Name: Date: June 27th, 2011 GIS Boot Camps For Educators Lecture_3

Transcription

1 Name: Date: June 27th, 2011 GIS Boot Camps For Educators Lecture_3 Practical: Creating and Editing Shapefiles Using Straight, AutoComplete and Cut Polygon Tools Use ArcCatalog to copy data files from: Y:\Sabah_2011_2012\GISBootCampForEducators\Day_1\Lecture_3 To your own workspace The objectives Create point, lines and polygon shapefiles Edit polygon shapefile In this exercise, you will use a digital aerial photo of the campus forest (GRCC Aerial.tif) as a background to digitize timber types using an editing session. Start ArcCatalog and connect to your folder of Lecture_3. You just paste it to your Data Right click "Data" folder to open "context menu" > Click New > Shapefile to open Create New Shapefile dialog Change the Name to Timber Types and Feature Type to Polygon and click edit 1

2 Setting coordinate system from referenced layer On Spatial Reference Properties Dialog click Import to open Browse for Dataset. Browse to GRCC geodatabase and click GRCC Aerial.tif and click Add What happened? Explain 2

3 Click OK to spatial Reference Properties to add Spatial reference to the Create New Shapefile dialog What is the projection of the Coordinate System of Timber Types shapefile? What is the Geographic Coordinate System of Timber Types shapefile? Click Ok to dismiss the dialog 3

4 Click Timber Types shapefile (Timber Types.shp) in ArcCatalog and activate Preview tab; you will not see any feature in the view because it is a new shapefile and no data were added to it yet. Change the preview to table to show an empty table with three attributes FID, Shape and ID Open ArcMap and click New Click Add Data tool and navigate to your workspace and double click on raster image "GRCC Aerial" to add it to the map. Or Drag the raster image "GRCC Aerial" from your workspace from the Catalog tree over to the ArcMap. Drag "Timber Types" shapefile over the ArcMap to add it to the table of contents and turn it on if necessary and drag it over the image if necessary. Save you map as "GRCC forest" to your "workspace" 4

5 What is the projection of this map? Right click on Layers to open the Data Frame Properties and right down the Current Coordinate System. Click "OK" to dismiss the dialog. Start Editing using the edit session If the editor toolbar is not available, click View on the main menu toolbar and select Customize from the" Main" toolbar menu. Click "Toolbars", then click "Editor" 5

6 You need to change the Timber Types symbology to hollow, wider lines (Outlines Width of 2) and brighter colors so you can see them better when you create new timber types using editing session. ( You should know how to do that by now) If you don t remember, that it is OK. Ask please. Click on the editor toolbar down arrow and select "Start Editing" to activate the "Editor Toolbar," and the "Create Features" dialog window opens. We have only one layer to edit. What is it? On Construction Tools, click Polygon. 6

7 Select "Timber Types". We have only one layer to edit. What is it? On Construction Tools click Polygon. Now the Editor Toolbar is active. On Data View Zoom into an area South of Campus. Start digitizing the Forest Types by clicking around the types using Straight Segment tool. You start digitizing by clicking on the start point and clicking around the timber type polygon, creating a vertex for each click, and at the end you will right click and click Finish Sketch to finish the first timber type. Save your edits. Digitize at least five more "Timber types". 7

8 Creating Adjacent Polygons If you are creating polygons of timber types, land uses, soils, or property ownership, you often need to create polygons that are adjacent to each other. The polygons should share a border, but you want to avoid digitizing the border twice. You should also avoid having overlaps and spaces between polygons (Slivers). You can use the Auto-Complete Polygon tool when creating new polygons to help ensure that your data form is a continuous fabric. Click "Timber Types" on the "Create Features" dialog to activate Construction Tools if necessary. Activate Polygon on "Construction Tools". Now change "Construction Tools" to "Auto Complete Polygon" To digitize adjacent polygons and to avoid having a duplicate shared line, you need to activate "Timber Types" in the "Create Features" dialog and select "Auto Complete Polygon" from "Construction Tools. 8

9 On the Editor Toolbar dropdown menu, Select Snapping Toolbar to open the Snapping toolbar. activate Point, and Edge Snapping Start editing by clicking anywhere around the polygon (edge or vertex). Continue digitizing the new polygon. You have to end with the same polygon. When you come to the edge or vertex of the adjacent polygon, double click or left click once and then right click to finish sketch. Check your attribute table to make sure that you have two adjacent polygons. The sketch must cross or intersect the existing polygon edge at least two times for the new polygon to be created. You must start and end within the existing polygon. Add few adjacent polygons. 9

10 Populate the ID attribute field with the record identification number starting from 1,2,3 and so on. Add as many attribute fields as you want (Remember you cannot add an attribute field when you are in Edit session). Stop editing and save edits. 10

11 Now add field to the attribute table name it "AreaAcre" and populate it with area Using "Calculate Geometry". Click "Yes" to Calculate Geometry" dialog after you read and understand the statement and question. From Calculate Geometry dialog select "Area" from "Property," and Select "Acres US [ac]" from "Units". Click "OK" to dismiss the dialog and populate the field 11

12 Classify the layer using "AreaAcre". If you don t remember how go to the last week assignment for details. If you still don't know how that is normal, don't hesitate to ask. Create" New Point Shapefile" name it "Plots" and" New Polyline" Shapefile name it "Trails" using the same method above. Add few features to each layer using the edit session. Save edit and then close editing. When you add new shapefile to the ArcMap and start editing you would not see the new shapefile in the Create features dialog Click on Organize Templates to open Organize Feature templates dialog 12

13 Click New Template to open Create New Templates Wizard and click Finish to create a template for new shapefile Then "Close Editing" and "Save" your map Export "Timber Types" to a new shapefile. Right click Timber Type1 > Data > Export Data and direct it to your workspace. Name it "Timber Types2". 13

14 In the "ArcMap" dialog, click "No" to add the exported data to the map as a layer Using Cut Polygons Tool Insert a new Data Frame" and name it "Cut Polygons. Copy "GRCC Aerial.tif " image from the first Data Frame and paste it into "Cut Polygons" Data Frame. Add "Timber Types2" to the Cut Polygons Data frame. Start editing. Activate the "Create Features" dialog and click "Cut Polygons Tool" 14

15 Divide the first polygon into two parts and the second into four parts Use the Edit tool to select the polygon you want to divide. Click on the edge or vertex and move to the other part of the polygon. Double click to divide it. When you are done digitizing "Save Edits" from Editor toolbar dropdown arrow menu. Select "Yes" to "Save" Dialog. Now on your own, create point and line shapefiles. Add at least three points and three lines. Finally, add a new Id field to each one and populate it with appropriate name. Digitize at least three buildings. Add a new Name field and appropriate it with appropriate name. Save your map. When you are done, move to Layout view to create a good map by adding and arranging all elements of a good map. Don t forget to add your name and date. When you are satisfied with your map, submit a hard color copy. Don t forget to export your map as PDF and add it to your own portfolio. 15