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Some ideas for students to think about while doing class evaluation Goals of the course: To teach anyone who wants to learn GIS, GIS. It is an intro course, so it tries to serve all knowledge levels.
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Some ideas for students to think about while doing class evaluation • Goals of the course: • To teach anyone who wants to learn GIS, GIS. It is an intro course, so it tries to serve all knowledge levels. • Trying to have you leave here with a solid grounding of GIS and GIS science fundamentals. I have the exam later in the semester because I think it is important for your learning to go back and think about the early class lecture content with some experience using GIS. • I teach using the hands on labs for two reasons. It allows me to show you how to do important GIS steps, but it also serves as a reference book for later. I know of NO book that provides you the steps I do in the coursepack. • – • Questions: • Are the computer hands on classes too tedious? • Would it be better to provide less structured or hand-holding classes? I know other classes try to do it this way, but I think for an introductory class this is a better way. If/when I teach an advanced course I am thinking that will be more free-form and open ended. But would like your opinion. • Should I move to a two-exam system? With one earlier in the semester? Will that take away from the idea that I think you learn rethinking the intro lectures after some time with doing GIS stuff? • Should I cut down the “GIS input” section of the class, and maybe not show address geocoding to give more time for the analysis stuff at the end? • Lab students: How did the lab 1 CR work? Would you recommend I do it again?
Analysis 1 ClassAttribute and “Select by Location” Queries (p. 230 Bolstad) • Select queries on the layer’s attribute table • ArcMap – selection menu, “select by attribute” queries • Neighborhood analysis (queries) • What’s adjacent? (In ArcMap – selection menu, “select by location” queries) • What’s nearby? (In ArcMap – selection menu, “select by location” queries) • We’ll do some exercises of this after this lecture
ANALYSIS 2 What kinds of analysis can we do with GIS? • Measurements • Layer statistics • Queries • Buffering (vector); Proximity (raster) • Filtering (raster) • Map overlay (layer on layer selections) • Transformations • Reclassification
Buffer zones around (a) point, (b) line, and (c) area features 4a. Buffering – Vector (p. 245 Bolstad) • Buffer at a specified distance; At a distance from an attribute field;and As multiple rings at a defined increment. • In ArcMap: ArcToolbox, Analysis tools, Proximity, Buffer wizard
7. Transformations • Functions to transform a layer of one feature type to another. Some examples: • Point to line: interpolation (contour mapping) (Bolstad ch. 13) • Point to polygon: buffering • Polygon to polygon: dissolve/merge (p. 243 Bolstad) • Raster to vector conversion • (In ArcMap, 3-D analyst extension, convert, raster to feature) • Vector to raster conversion • (In ArcMap, 3-D analyst extension) • Raster to Triangular Irregular Network (TIN) • In ArcGIS, 3-D analyst extension • Resampling a raster grid – convert one cell size to another cell size
Vector overlays: (a) point-in-polygon 6a. Vector Overlay – Point-in-Polygon (p. 256 Bolstad) • Point-in-Polygon is used to find out the polygon in which a pointfalls. • Example: Which landcover does each meteorological station fall into? • Bolstad notes a problem going the other way – polygon to point. • Anyone remember?
Vector overlays: (b) line-in-polygon 6b. Vector Overlay – Line-in-Polygon • Line-in-Polygon: Used to find out what polygons a line falls within. • More complicated than point, because one line can be in more than onepolygon • Example: Which roads pass through forest areas? What parcels might be affected by a new bike trail design?
Vector overlays: (c) polygon-on-polygon Where are areas of forestry OR areas within the resort? 6c.Vector Overlays:Polygon onPolygon(Bolstadp. 261) Where is the resort boundary and where is there forest within the resort? Also called “clipping” Where is there forest within the resort? Note: Problem of “sliver polygons” – when boundaries don’t coincide exactly
6d. Vector Overlay – In ArcMap • ArcToolbox/Geoprocessing • Available Functions: • Union – see slide 6c. “Atbox-An Tools-Overlay-Union” • Intersect – see slide 6c. “Atbox-An Tools-Overlay-Intersect” • Clip (“cookie cutting”) – see slide 6c. “Atbox-An Tools-Clip” • Merge – appends two or more layers together to create a new layer (e.g., side by side). “Atbox-Data Management Tools-General-Append” • Dissolve – reduces number of features by merging adjacent features with the same attribute value. Creates a new layer. “Atbox-Data Management Tools-Generalization-Dissolve”