Planning a GIS progect

Scott Crosier, Bob Booth, Katy Dalton, Andy Mitchell, Kristin Clark.

Planning a GIS progect In a typical GIS analysis project, you identify the objectives of the project, create a project database containing the data you need to solve the problem, use GIS functions to create an analytical model to solve the problem, and present the results of the analysis.

Step 1: Identify your objectives

The first step of the process is to identify the objective of the analysis. You should consider the following questions when you are identifying your objectives:

- What is the problem to solve? How is it solved now? Are there alternate ways to solve it using a GIS?

- What are the final products of the projectreports, working maps, presentation quality maps?

- Who is the intended audience of these productsthe public, technicians, planners, officials?

- Will the data be used for other purposes? What are the requirements for these? 

This step is important because the answers to these questions determine the scope of the project as well as how you implement the analysis.

Step 2: Create a project database

The second step is to create a project database. Creating the project database is a three-step process. The steps are designing the database, automating and gathering data for the database, and managing the database. Designing the database includes identifying the spatial data you will need based on the requirements of the analysis, determining the required feature attributes, setting the study area boundary, and choosing the coordinate system to use. Automating the data involves digitizing or converting data from other systems and formats into a usable format, as well as verifying the data and correcting errors. Managing the database involves verifying coordinate systems and joining adjacent layers. Creating the project database is a critical and time-consuming part of the project. The completeness and accuracy of the data you use in your analysis determines the accuracy of the results.

Step 3: Analyze the data

The third step is to analyze the data. As you’ve seen, analyzing data in a GIS ranges from simple mapping to creating complex spatial models. A model is a representation of reality used to simulate a process, predict an outcome, or analyze a problem. A spatial model involves applying one to three categories of GIS functionality to some spatial data. These functions are:

- Geometric modeling functions calculating distances, generating buffers, and calculating areas and perimeters.

- Coincidence modeling functions overlaying datasets to find places where values coincide.

- Adjacency modeling functions allocating, pathfinding, and redistricting.

With a GIS you can quickly perform analyses that would be impossible or extremely time-consuming if done by hand. You create alternative scenarios by changing your methods or parameters and running the analysis again.

Step 4: Present the results

The fourth step is to present the results of your analysis. Your final product should effectively communicate your findings to your audience. In most cases, the results of a GIS analysis can best be shown on a map. Charts and reports of selected data are two other ways of presenting your results. You can print charts and reports separately, embed them in documents created by other applications, or place them on your map.

What’s next?

Now that you have reviewed the steps in a GIS project, you are ready to begin planning your own project. The next section presents an overview of the steps for the Greenvalley wastewater treatment plant project. The first step identifying the project objectives is covered in this chapter. The rest of the steps comprise the remaining chapters in this book.