Hazards Planning and Risk Management Lecture No. 07 GIS Lab 2 Fall 2016 US – Pakistan Center for Advanced Studies in Water

Learning Objectives Using arcgis How to 1. Digitize 2. create a gis layer from tabular data 3. geo-reference an image

Digitizing - Buildings - Roads Digitize on rectified image

Creating and Adding New Layers Create New feature layers through ArcCatalog Polygon – for Buildings Feature class name = Buildings Add Field ‘Building_Type Line – for roads Feature class name = Roads Add Field ‘Road_Type’ Add New feature layers in ArcMap

Digitizing Roads

Creating Templates Right click Roads layer, go to properties > symbology > categories > unique values Value Field = Road_Type Add Values Highways Roads Local Roads OK, OK (symbology window)

Organizing Template Editor > Editing Window > Organize Feature Template (Create Feature window) Select ‘Roads’ Click ‘New Template’ Check Layer ‘Road’ Next Check Template Names √ Highways, √ Roads, √ Local Roads Finish Close ‘Organize Feature Template’

Start Digitizing Select type of Road (Highway, Roads, or Local Roads) from ‘Create Feature’ window Click the starting point (snapping is on as a default) Keep clicking along the road by adding vertices At finish point either Double click Click F2 Right click > Finish Sketch Select another template and create sketch

Digitizing Buildings

Class Assignment Digitize buildings in the image

processing tabular data

Look at Google Earth Image

Look at Google Earth Image

Converting XY Table into Point Feature Class Get longitude (X) and Latitude (Y) from Google Earth http://support.esri.com/es/knowledgebase/techarticles/detail/27589

longitude (X) and Latitude (Y) from Google Earth Save in Excel Convert in Decimal Degree format Add Excel worksheet in ArcMap Add Data > Add XY Data (geographic coordinate system, WGS 1984) Select a coordinate system for the data Points will be drawn as an event theme in ArcMap

Convert the event theme to a shapefile or geodatabase feature class Right-click the file name, select Data > Export Data Points can be exported to a geodatabase feature class or to a shapefile Re-project to the UTM coordinate system

georeferencing

Georeferencing Save Google Earth Image (jpeg) Select Ground Control Points (GCP) At least 3 points are required for Affine (1st Order polynomial transformation) Add Georeferencing tool bar Apply ‘Fit to Display’ on the image Add GCPs Update Georeferencing when satisfied Rectify for permanent transformation