Module 1: GIS for Developing Contingency Plan¶
Learning Objectives
Distinguish between data and information
Understand the concept of GIS
Difference between data and information¶
In the first unit, we looked at OpenStreetMap and how to collect data and add it to the worldwide map. But what do we mean when we say that we collect data? Is this the same as collecting information? Well, not exactly.
Data are raw facts. Information is data that is organised and presented in such a way as to be useful. In other words, when we go mapping to collect locations and facts about those locations, we have collected data - we have collected facts. To turn this data into information, we must make sense of it. We must present the data in such a way that it can be easily understood.
OSM data is already made informative in an obvious way. The map that you see when you visit the OSM website is there because a computer has processed all of the OSM data and used it to paint a nice looking map. The map is informative, and useful for us to see where places are in relation to us.
In this unit we will take this even further. We will learn how to perform geographic data analysis, and thereby learn how to make our data more useful, informative and effective.
Terminology of Geographic Information Systems (GIS)¶
A Geographic Information System (GIS) is a system designed to enable people to work with data related to places on the Earth. A GIS allows the creation, storage, manipulation and analysis of geographic data. GIS is a very broad concept and can involve complex hardware and software. But for most people’s purposes, a simple GIS software application is all that is required, and in this unit we will learn how to use the excellent open-source application, QGIS.
GIS provides different ways of analysing data. It enables us to ask complex questions, such as:
Where are all schools with more than 100 students?
How many children live in a certain district?
How many women live within 500 metres of a certain hospital?
What is the shortest walking path from a given point to a hospital?
GIS helps us to answer these sorts of questions. In the previous unit we learned how to collect data, and in this unit we will see how to analyse it.