GIS Class Guide 18 APRIL 2017
Intro to rasters and label power
We're back from Spring break and have three more sessions to go before our project presentations and mapping celebration. Our goal is to have our data analyzed and displayed to share by the end of class on 2 MAY so we can polish between then and the 9th.
Activity 1: Raster concepts
ESRI Has a nice primer on raster data which would be valuable to review along with Kurland and Gorr chapter 11. Our task will be to investigate this question: which flood-prone areas in PGH would we want to target first for flood abatement measures?
- Follow steps in Kurland And Gorr Ch 11, tutorial 1 and 2 to extract a land use raster layer and a hillshade raster layer.
- Download the shapefile of FEMA designated flood zones from the WPRDC HERE
- Add flood zones to your map. Use "feature to point" tool to create a set of points in the centroids of each flood zone.
- Use the extract values to points tool to associate a land use value with each flood point.
- Open the attribute table of the new point layer and see that the last column is named "RASTERVALU" which came from the cell on which the point rests. Sort this list. Check the land use symbology to determine which land use code marks areas of high and medium development.
- Select High concern flood areas and export that layer. Symbolize and create a layout
Activity 2: Labels Revisited
We can create labels that we can move to just the right point by converting labels to annotations and storing them in their own feature class, just like a layer, and turn them on and off, change symbology, etc. We'll practice this in class today.
Project work time
Take the remainder of the class time to keep working on your project and we can troubleshoot as needed