Geographic Information Systems (GIS)

Definition. A geographic information system is:
·    A computer software system (with supporting hardware)
·    that manages data pertaining to land, water, and air resources,
·    such that one can store and retrieve such geographic information
·    as well as analyze stored information or additional parameters derived from stored information.

A geographic information system (GIS) integrates hardware, software, and data for capturing, managing, analyzing, and displaying all forms of geographically referenced information.
GIS allows us to view, understand, question, interpret, and visualize data in many ways that reveal relationships, patterns, and trends in the form of maps, globes, reports, and charts.
A GIS helps you answer questions and solve problems by looking at your data in a way that is quickly understood and easily shared.
GIS technology can be integrated into any enterprise information system framework

Implementing GIS
A working GIS integrates five key components: hardware, software, data, people, and policy and procedures

Hardware and Software

Hardware is the computer on which a GIS operates. Today, GIS software runs on a wide range of hardware types, from centralized computer servers to desktop computers used in stand-alone or networked configurations.

GIS software provides the functions and tools needed to store, analyze, and display geographic information. Key software components are :

·    Tools for the input and manipulation of geographic information.
·    A database management system (DBMS)
·    Tools that support geographic query, analysis, and visualization
·    A graphical user interface (GUI) for easy access to tools

The affordability of desktop computers with an increasing computing power and decreasing cost of software has resulted in widespread desktop GIS.

Data

Data is one of the most important and costly component in implementing GIS. Database is the longest living part of any GIS implementation. Building the database takes the longest time, costs the most money, and requires the most effort in terms of planning and management. Implementing GIS requires adequate emphasis on database planning and choosing the right information base for the particular applications of an organisation.

Most GIS applications in a particular area require a common set of spatial data (figure 9.2). However, these data are often possessed by different organizations. Due to the lack of proper data sharing mechanism, different organizations are involved in collecting the same data, thus wasting resources and time. This duplication of effort is also due to insufficient or inappropriate standards in data collection. The major problem in reuse of data is the lack of awareness or willingness to share the data among the organizations. GIS as a technology will only be viable and cost-effective, if data is readily available at affordable cost.

People

GIS technology is of limited value without the people who manage the system and develop plans for applying it to real-world problems. GIS users range from technical specialists who design and maintain the system to those who use it to help them perform their everyday work. GIS constitute truly an interdisciplinary field and require varied backgrounds of expertise, depending upon the applications. It requires input from the computer and information technology experts for the system support and the input from domain specialists for application specific models and analyses.

Policies and Procedures

A successful GIS operates according to a well-designed plan and business rules, which are the models and operating practices unique to each organization. GIS exist in the context of application within an organisation. For example - in the case of municipal GIS applications, it will have different functional requirements compared to GIS for agriculture or land use planning.

Besides the technical components like hardware, software and databases, institutional framework and policies are also important for a functional GIS. The interest and willingness of decision makers in exploiting GIS technology, and the organisational set up for collecting spatial data, analysis procedures, and using the results for planning and implementation form a very important component in a GIS.
Choosing the right GIS for a particular GIS implementation involves matching the GIS needs to the functionality demanded by the types of application of an organisation.