Setting Up a Geoprocessing Environment
It can be fun to fool around with GIS -- you can use tools to transform data and examine the results, we can learn a lot this way. But when setting up the parameters of processing tools and developing loads and loads of derived data becomes a bore, we will be happy to know that there are ways to automate chains tasks so that they can be adjusted and repeated without having to repeat each step. We can use these prescribed workflows (known in ArcGIS as Geoprocessing Models) to document our work. This is a wonderful way to share your work and your data with other people so that they can better understand what you did, and even to extend your work. This way of sharing work and advancing knowledge can be very rewarding for individuals, and is especialy important for organizations that can't afford to stat from scratch on work that has already been done!
Background and Deeper Reading
- Beginning a GIS Database explains the folder structure that is assumed in this tutorial.
- Geoprocessing in ArcGIS the ESRI User Guide.
- What is Geoiprocessing
- A whirlwind Tour of Geoprocessing
- An Overview of Model Builder
Setting Up your Modeling Laboratory
The tutorial Beginning a GIS Database explains a framework for orgaizing data for a team of collaborators working on a project. The principles described there provide a framework for organizing project data so that many people can share and contribute to a common base of GIS data, each user having their own workspace in the GIS folder. By careful attention to the use of relative pathnames, this entire project directory tree can be worked on by many different collaborators without conflicts developing between different users trying to develop data in the same location. This tutorial explains how to arrange a working directory so that users can develop and share tools that operate on project data, creating result datasets in that user's scratch and data folders.
Set Up your Working Directory
- Create your working directory in the GIS folder of the project dataset.
- Create sub folders for tools, a docs, a scratch folder and a data folder.
Set your Groprocessing Options and Environment
We will make a toolbox that will hold the geoprocessing models that we make. These models will create new data. SOme of the data we crerate will be intermediate (scratch) layers that may be deleted when the model is through. Other datasets we may want to save when the model is through. The following steps will let us inform ArcMap where we want tour toolboxes to be created and where your scratch and persistent output data will go.
Set your Geoprocessing Options
- Go to Tools->Options->Geoprocessing
- The location of your My Toolboxes Folder should be your Tools folder.
- Overwrite results of geoprocessing options
- When connecting elements, display valid parameters when more than one is available.
- After clickng Tools->Options->Geoprocessing->Environments->General Settings, set:
- Workspace = your data folder
- Scratch workspace = your scratch folder
- There are many other geoprocessing environment settings that you may also want to set, you can read about these in the on-line documentation.
Practicing with Geoprocessing Models
The following exercise will introduce the basics of model builder.