
Introduction
Location Map
GIS Concepts
Conventions
Database Schema
GIS Analysis Flowchart
Custom GIS Analyses
PHP Code
Base Map
Results: John Martin SWA
Results: Lower Gunnison
Conclusion
References
This project required extensive manipulation of the source data layers. We used projection, selection, calculation, and extraction, as well as more advanced processing to generate tables of attribute data and joining the tables back to the original feature sets. A more detailed description of the processing steps can be found on the GIS Analysis Flowchart page of the web site.
The tools listed below are located in ArcToolbox within ArcMap.
Analysis Tools
Extract- selects features and the attributes in a table or feature class, the combined attributes are saved in a feature class or table; an extract tool is "clip"
Clip- extracts input features that overlay the assigned "clip" features (Data Mangement Tools for Raster Datasets)
Overlay- used to incorporate, erase, transform, or update multiple feature classes, developing a new feature class; an example of an overlay tool is "spatial join"
Spatial Join- transfers the attributes from on feature class to another, based on spatial relationships between the features
Conversion Tools
Polyline to Raster- converts polyline features to a raster dataset, all feature classes containing a polyline are transformed into a raster dataset
Raster to Point- converts a rater dataset to point features; every cell of the input raster dataset is created into a point in the output feature class
Data Management Tools
Merge- Combine datasets from various sources into a new, single output dataset/ all datasets must be the same feature class- (ex. Polyline to polyline, table to table)
Hawth's Tools
An extension of analysis tools for ArcGIS designed to carry-out spatial analysis functions that cannot be completed with out-of-the box ArcGIS; a Hawth's tool is "distance between points"
Distance Between Points- the input is a point layer, and the output is a table summarizing the distance between points
Spatial Analysis Tools
Distance- (Euclidean) - measures straight line distance from each cell to the closest source, the source is an object of interest; roads, buildings, etc.; a distance tool is "cost distance"
Cost Distance- associates a cost with traveling any distance over a cell Reclassify- change values in a raster
Map Algebra- an important tool in combining information or analyzing individually to solve problems. Allows the user the ability to create equations to find answers. a map algebra tool is "single output algebra"
Single output Algebra- runs a single expression built from the map algebra language
Zonal Geometry- used to compute area, perimeter, thickness, or centroid of each input zone
Zonal Geometry as Table- table with a summary of the geometry for each zone
Zonal Statistics- calculates statistics on values of a raster within the zones of another dataset
Zonal Geometry- calculates for each zone in a dataset the specified geometry measure (area, perimeter, thickness, etc.)
Zonal Statistics as Table- table with a summary of the statistical values for each zone
Information provided by Environmental Systems Research Institute (ESRI)