Copyright © 2006 by Maribeth H. Price 1-1 Chapter 1 Introducing ArcGIS

Copyright © 2006 by Maribeth H. Price 1-2 Outline What is GIS? Some GIS applications Introducing the ArcGIS products How does GIS work? –Basic data formats –The ArcCatalog interface

Copyright © 2006 by Maribeth H. Price 1-3 What is GIS? Software combining spatial mapping and analysis with database management

Copyright © 2006 by Maribeth H. Price 1-4 With GIS you can: Create maps, graphs, and reports Create and manage map data Analyze spatial relationships Overlay map data from different sources Manage and display database information Locate addresses Analyze utility and transportation networks

Copyright © 2006 by Maribeth H. Price 1-5 Example –soils –geology –vegetation communities –slope –aspect –distance to water –distance to roads –satellite-derived vegetation index (NDVI) –satellite-derived moisture index (NDMI) Compare 1998 horseback thistle survey to easily assessed environmental parameters Predicting thistle occurrence in Badlands National Park

Copyright © 2006 by Maribeth H. Price 1-6 Thistle habitat prediction map

Copyright © 2006 by Maribeth H. Price 1-7 Application—Wildlife habitat model HABCAP model (U.S. Forest Service) –Uses available vegetation/roads data –Assesses suitability of a forest stand Availability of forage (FV = 0-1) Availability of cover (CV = 0-1) Proximity of forage and cover (PV = 0-1) –Both together are more valuable than either alone Distance from roads –Each stand is given a final suitability score 0-1 –Uses a variety of GIS analysis techniques

Copyright © 2006 by Maribeth H. Price 1-8 Each polygon is assigned a coefficient for cover (CV) and forage (FV) availability based on the vegetation type and structure (COVSS) Reclassification

Copyright © 2006 by Maribeth H. Price 1-9 Dissolving Then the polygons are dissolved, removing the internal boundaries between polygons with the same designation. Based on the coefficient values, the polygon is given the designation as primarily cover (C), primarily forage (F), or both (B)

Copyright © 2006 by Maribeth H. Price 1-10 Proximity analysis Ideal habitat area based on proximity: B (contains both forage and cover) Areas of F polygons that are close to the boundary of a C or B polygon Areas of C polygons that are close to the boundary of a B or F polygon

Copyright © 2006 by Maribeth H. Price 1-11 Buffering PV = 1.0 PV = 0.5 PV = 0.2 First we extract only the C and F polygons. Because of the previous dissolve, the boundaries of these polygons all represent ideal habitat edges Multiple buffer zones are created inside each polygon, representing distances from the boundary. Closer areas get a higher suitability rating.

Copyright © 2006 by Maribeth H. Price 1-12 Calculation of suitability HS is the final suitability rating for each polygon Use the coefficients (0-1) determined for cover (CV), forage (FV) and proximity of cover and forage (PV) HS = (3*FV * CV * PV) / 5 HS

Copyright © 2006 by Maribeth H. Price 1-13 Road buffers HS Buffers are created around primary and secondary roads. Primary roads get larger buffers. Areas close to roads have HS halved. Roads Final HABCAP result

Copyright © 2006 by Maribeth H. Price 1-14 What is ArcGIS? Description and history of the ESRI GIS family

Copyright © 2006 by Maribeth H. Price 1-15 A history of products Arc/Info Arc ArcPlot Info/Tables ArcEdit GRID ArcView 3x ArcGIS ArcMap ArcInfo Workstation ArcCatalog ArcToolbox ArcGIS Desktop CoveragesShapefilesGeodatabases

Copyright © 2006 by Maribeth H. Price 1-16 ArcGIS Desktop ArcCatalog ArcMap ArcToolbox

Copyright © 2006 by Maribeth H. Price 1-17 ArcGIS functionality Three levels of functionality and cost $$$ArcInfo $$ArcEditor $ArcView Same interface and programs More tools in the toolbox

Copyright © 2006 by Maribeth H. Price 1-18 ArcGIS Extensions Spatial Analyst 3D Analyst Publisher/ArcReader Network Analyst Maplex Geostatistical Analyst Extensions are additional tools and commands that can be added to the core ArcGIS interface Appear as new toolbars and toolsets in ArcCatalog

Copyright © 2006 by Maribeth H. Price 1-19 Licensing Floating point licenses –ArcInfo only –Central server checks out licenses –Requires a dongle and a license file Standalone licenses –Uses a registration file/ register online –No dongle needed –Available for ArcView and ArcEditor only

Copyright © 2006 by Maribeth H. Price 1-20 How does GIS work? Data storage The ArcGIS Interface

Copyright © 2006 by Maribeth H. Price 1-21 GIS data models Vector model Raster model

Copyright © 2006 by Maribeth H. Price 1-22 Vector model Vertices Polygon Points Nodes Line X Y Features are stored as a series of x-y coordinates in a rectangular coordinate system. Many different coordinate systems may be used.

Copyright © 2006 by Maribeth H. Price 1-23 X-Y Coordinate systems/units: Longitude-latitude (degrees) State Plane (feet) UTM (meters) Some familiar coordinate systems can be found on a topo map.

Copyright © 2006 by Maribeth H. Price 1-24 Features linked to data Each feature is linked to an entry in a data table containing information about the feature.

Copyright © 2006 by Maribeth H. Price 1-25 Feature classes A collection of similar objects with the same attributes States feature class Cities feature class

Copyright © 2006 by Maribeth H. Price 1-26 Advantages of vectors Precise location of features Storing many attributes Flexible for cartography Compact storage of information Ideally suited for certain types of analysis, especially areas, lengths, connections

Copyright © 2006 by Maribeth H. Price 1-27 The raster data model Rows Columns X, Y location Raster data file N rows by M columns X, Y location Georeferenced to earth’s surface

Copyright © 2006 by Maribeth H. Price 1-28 Types of raster data Discrete raster: land use Continuous raster: DEM Continuous raster: image Discrete raster: roads

Copyright © 2006 by Maribeth H. Price 1-29 Continuous data Raster is the best way to store continuously changing values such as elevation Analysis faster and more flexible than vectors for many applications Some analysis only possible using rasters

Copyright © 2006 by Maribeth H. Price 1-30 Raster analysis functions Density Least cost path DistanceInterpolation Viewshed Buffers

Copyright © 2006 by Maribeth H. Price 1-31 Impact of resolution Storage space increases by the square of the resolution Portraying large areas at high precision is problematic 90m resolution 10m resolution

Copyright © 2006 by Maribeth H. Price 1-32 Storage of attributes Roads may have other attributes: ownership, speed limit, number of lanes, etc. Would need a new raster for each attribute Only numeric attributes may be stored Raster contains 1 value indicating a single attribute— road type for example

Copyright © 2006 by Maribeth H. Price 1-33 The ArcGIS Interface Menu bar Tool bars Tear-off/dock Display window Context menu More toolbars

Copyright © 2006 by Maribeth H. Price 1-34 The Tools toolbar Zooming and panning Full extent Pointer tool Identify attributes of features Find text in attributes Measure distances

Copyright © 2006 by Maribeth H. Price 1-35 Context menus Right-click name Right-click symbol Left-click symbol Menus pop up when certain objects are clicked

Copyright © 2006 by Maribeth H. Price 1-36 What is a layer? Spatial data file Associated properties Held in memory in ArcMap Used as inputs to functions/tools May be saved as a file

Copyright © 2006 by Maribeth H. Price 1-37 Layer Properties Property tabs

Copyright © 2006 by Maribeth H. Price 1-38 Data formats CoveragesShapefilesGeodatabases

Copyright © 2006 by Maribeth H. Price 1-39 Topology Information and rules stored about spatial relationships between features and feature classes A B Polygon A is composed of a label and two arcs. Polygon A is adjacent to polygon B and shares one common arc. A dangle error—the two lines fail to connect Correct topology Self- intersecting loop error gap overlap Polygon errors

Copyright © 2006 by Maribeth H. Price 1-40 Topology rules Shannon County Bennett County Pine Ridge Indian Reservation South Dakota Nebraska Topology rules establish how features should be spatially related. Topology rules may apply within a layer or between layers. No gaps or overlays between counties The Pine Ridge and Bennett County boundaries should match The South Dakota and Pine Ridge boundaries should match These three layers show several topology errors.

Copyright © 2006 by Maribeth H. Price 1-41 Shapefiles Shapefiles in Windows Explorer Shapefiles in ArcCatalog Coincident boundary One feature class Multiple files Simple features No topology Dbf tables From ArcView

Copyright © 2006 by Maribeth H. Price 1-42 Coverages Multiple feature classes Topological features Many files Info tables From Arc/Info Topology is information stored about spatial relationships between features. Polygon A is composed of a label and two arcs. Polygon A is adjacent to polygon B and shares one common arc. A B

Copyright © 2006 by Maribeth H. Price 1-43 Geodatabases Single file Multiple feature classes Access database technology Feature datasets Simple and topological features Validation rules Customized object behavior

Copyright © 2006 by Maribeth H. Price 1-44 Other types of data Rasters Tables Layer files CAD Drawings

Copyright © 2006 by Maribeth H. Price 1-45 Geoprocessing Stringing together commands and analysis functions to achieve a result Menus Tools Command line Model builder Scripts

Copyright © 2006 by Maribeth H. Price 1-46 Important Although Windows permits spaces in file and folder names, in GIS they are a BAD IDEA. They often work, but sometimes a certain program or function will fail if it encounters a space in a folder name. Real GIS users FLINCH when they see spaces anywhere in folder/file names— even when they’re allowed!

Copyright © 2006 by Maribeth H. Price 1-47 Metadata Contains information about data that people need to properly understand and use the data Created with and copied with data Create Edit Update Import Export Fig. 22. The metadata toolbar lets you create, view, and edit metadata for your layers.

Copyright © 2006 by Maribeth H. Price 1-48 AVOID SPACES IN FOLDERS and FILENAMES Spaces are Evil

Copyright © 2006 by Maribeth H. Price 1-49 Connecting to folders

Copyright © 2006 by Maribeth H. Price 1-50 The ArcCatalog Interface Folder tree Display window Menu/tool bars

Copyright © 2006 by Maribeth H. Price 1-51 Three view modes ContentsPreviewMetadata

Copyright © 2006 by Maribeth H. Price 1-52 Tables in ArcCatalog

Copyright © 2006 by Maribeth H. Price 1-53 Getting Statistics

Copyright © 2006 by Maribeth H. Price 1-54 File Properties Right-click file name

Copyright © 2006 by Maribeth H. Price 1-55 Did I mention that you should avoid spaces in folder and file names?