Analysis In Arcgis

ANALYSIS IN ARCGIS

DEFINITION

“A systematic examination of a problem or complex entity in order to provide new information from what is already known.”

WHY DO ANALYSIS?

To confirm or deny any hypothesis  To explore data  To develop a visualization 

process

Link

Questions usually answered What exists at a particular location on the face of the earth (locational analysis)?  When is a specific spatial condition satisfied?  What has spatially changed over time?  What kind of pattern will emerge from geographical data?  What will happen if certain criteria is entered in to a predetermined scenario? 

Analysis - further 

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Locational Analysis – Mapped data primarily indicates where objects are located but cannot explain why. Satisfying a Spatial Condition – Frequently a GIS user wants to discover whether the mapped data will meet certain conditions. Temporal analysis – Analyze changing patterns over time by storing and comparing maps of different dates. Emerging Patterns – Analyze if two or more things vary similarly over space. Evaluating Different Scenarios – Sometimes a change in assumptions results in a forecast that is substantially different. Being able to answer a “What if …?” scenario.

Analytical and operational functions Projection and Spatial Transformation Utilities  Spatial Retrieval, Classification and Measurement Functions  Logical and Visual Overlaying Capabilites  Proximity and Network Functions  Map Algebra Utilites  Output Generation 

Tools in analyzing (All tools are maintained as toolsets in arcgis toolboxes) A toolbox can contain tools, toolsets, and scripts and is organized according to the collection of geoprocessingcommands it contains. Is available both in ArcMap and ArcCatalog A toolset can contain tools, toolsets, and scripts and is organized according to the geoprocessing commands it contains. Is available both in ArcMap and ArcCatalog

Types of tools and toolsets System Tools – Installed with the software Model Tools – These tools are created using the ModelBuilder. Some of the tools in the system toolboxes are model tools. Script Tools – These tools are created by the user using a scripting language, for e.g, Python, Javascript, VBScript. Some of the tools in the system toolboxes are script tools.

How to access the toolboxes? 

Through the ArcToolBox Window in ArcCatalog and ArcMap

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Access online Geoprocessing tasks hosted by ArcGIS Server through internet and intranet ArcGIS Server is a comprehensive Web-based GIS that provides a range of out-of-the-box applications and services for mapping, analysis, data collection, editing and management of spatial information.

Some examples of analysis Find coastal sage scrub near proposed roads  Analyze the different tree types near Wallenberg Hall 

conclusion GIS is an integrated approach to manage and analyze map and attribute data.  The increasing importance of GIS can be attributed to its ability to support decision making.  Contingent on: 

Data accuracy Data quality Data scale 

Data documentation is very important to assure the integrity of the data.

Further readings The ESRI Guide to GIS Analysis, Volume 1 Geographic Patterns and Relationships – Andy Mitchell  The ESRI Guide to GIS Analysis, Volume 2 Spatial Measurements and Statistics – Andy Mitchell 