Question

A geographic information system is a conceptualized framework that provides the ability to capture and analyze spatial and geographic data. Discuss the following. If required, include the pictures. (20marks)

1. Definition and explanation of GIS

2. Components of GIS

3. Data and Data Sources of GIS

4. GIS Applications

Answer 1

1) A geographic information system, as the name suggests, gives information about the geographic components of an area such as streets, buildings and vegetation. It is a computer system that captures, stores and displays data related to geographical components of Earth's surface.

It allows users to view, interpret and analyze spatial and geographic data in various ways that reveal relationships, patterns and trends about various factors such as vegetation, population, soil etc. Various locations can be compared to each other by GIS. The indexing varaiable used to relate all data in GIS is location, i.e., all data in GIS is stored using the date and time of occurence (called spatio-temporal) as the key element. For example, if a user wants to view population of a certain location, they can enter the location co-ordinates of that location and the date (for which population is to be known) to view, analyze and interpret the data.

2) Components of GIS are- hardware, software, people, methods and data.

• Hardware- It is the computer system on which GIS operates. Wide range of hardwares are used for GIS e.g., a centralized server, a desktop computer etc.
• Software- It provides the process to view, analyze and interpret the data of GIS. It may contain GUI ( Graphical User Interface), DBMS ( DataBase Management System) and many other tools for input, analysis and manipulation of data.
• People- Those who develop, design, maintain and use GIS come under this category.
• Methods- These include business plans and operating mechanisms for using GIS.
• Data- This is the most important component of GIS. It contains geographic and tabular data. A DBMS (DataBase Management System) can be used to store, organize and manage data.

3) The data of GIS can be collected in- house or purchased from any other organization or website. There are two types of data required- spatial and attribute. Spatial data denotes the location (like the location co-ordinates of a forest) and attribute data contains the characteristics of those locations (like dominant species of that forest). The data may include aerial photographs, maps, remotely sensed imagery or existing digital data files.

4) Applications of GIS include mapping (example,Google Maps), accident analysis, urban planning, transportation planning, vegetation analysis, analysis of extinction of species, disaster management and mitigation, navigation, flood estimation, natural resources management and visualization of polluted locations.