Geographic Information System (GIS): a useful tool for analysing data in policy making decision
[Editor’s note: This post was written by Pareexit Chauhan, GIS Analyst, and Dr. Gaurav Kapoor, Senior Research Scientist at the Center for Study of Science, Technology and Policy (CSTEP).]
What is GIS?
According to the Wikipedia, “a Geographic Information System (GIS) is a system designed to capture, store, manipulate, analyse, manage, and present all types of spatial or geographical data”.
GIS, simply put, is technology that combines geography with information. Using GIS, portions of relevant datasets are represented spatially thereby creating a frame of reference for users of those datasets. Since the datasets are referenced to physical locations on earth, problems can be understood and analysed from a real-world perspective.
GIS can also be thought of as a decision making tool to help policy makers, planners, and researchers in taking efficient decisions related to problems requiring location-based analysis such as disaster management, urban planning, e-governance, transportation etc.
The main advantages of GIS are flexibility, cost effectiveness, accuracy, speed and ability to handle large volume of spatial and non-spatial data. For example, one can analyse extreme parts of the world like dense forests, deserts and Polar Regions easily using satellite imagery and GIS techniques. If large-area studies are required (e.g. for an entire country) and the research is done using surveys and site visits then one needs a lot of resources such as money, time and man-power. But with the help of GIS software one can reduce the resource requirement drastically.
How does it work?
Information in a GIS is organised in the form of layers. Each layer adds a unique dimension to the system. For example, the base layer could be a map of the area of interest (this could be a country, a city, a village etc.). The next layer could contain information about the various population centres in the area and their growth rates. The third layer could contain information about the natural features (precipitation, water resources, temperature, forest cover etc.). Intersecting these layers (or datasets) using GIS tools such as QGIS or ArcGIS could then not only give insights on how much water will be required by that area over the forthcoming years but also answer questions such as where to locate new watersheds based on the geographic contours, where to lay pipelines and how to plan for movement of the population.
A basic building block in GIS is an Attribute Table – “A database or tabular file containing information about a set of geographic features, usually arranged in rows and columns so that each row represents a feature and respective column represents feature’s information”. For example, if we are analysing an organisation, the location of the organisation is the spatial data and the additional information like name of organisation, type of the organisation, number of employees etc. are part of the Attribute Table.
Some of the sectors within policy research that GIS have been applied to are:
Mapping of civic resource locations (police stations, hospitals, shelters),
Planning for evacuation routes, Communication networks
Study of crop patterns,
Location, planning and distribution of water resources
Forest cover degradation over time, migratory patterns of wildlife
Census and Elections
Patterns of population growth and movement
Patterns of voting
At CSTEP, GIS has been used extensively in almost all research domains including Energy, Security and Climate change. One research question that was recently addressed was the Renewable Energy Assessment for India.
Renewable Energy (RE) has emerged as one of the key pathways for developing countries such as India to meet their national goals of accelerated development, complete energy access and sustainable energy security. The important sources of RE in India include solar, wind, geothermal, small hydro and biomass. The Government of India has recently announced targets of 100 GW of solar capacity and 60 GW of wind capacity installation by 2022.
One of the challenges to RE deployment is the identification and location of suitable sites. The goal of site selection is to concentrate on the best available sites in India for RE technology deployment. It is here that the the application of GIS to the analysis of RE potential can offer critical insights. These GIS methods help examine the relationships between multiple layers of geographic information and can support prioritising development of RE resources.
A lot of factors go into making a site suitable for RE deployment: good resource strength, availability of suitable and spacious land for installation, proximity to the power grid (for evacuation), proximity to road networks, proximity to water bodies and information on location specific economics are some of these factors. In addition, due consideration has to be given to sensitive issues such as environmental degradation. For example, forest lands in India have been restricted from any developmental activities in the recent years due to environmental issues. On many occasions, the best resource strength may be available in such restricted areas. Usually agricultural lands are also not used for developmental activities, although that is now slowly changing due to farmers and land owners earning extra income by renting out to RE installations, in addition to their regular farming earnings.
To define solar and wind suitable zones we identified the different types of land suitable for installing wind or solar power plants. From the land use land cover data of India we have to eliminate those areas which are not suitable for development of a wind power plant like urban area, water bodies, area having more than 45 degree terrain slope and 1500m elevation form the sea level etc. These are then spatially joined (a technique similar to set intersection) with wind and solar data sets having wind speed and wind power density and solar irradiation. After applying specific formulae, one can easily calculate the potential for the area of interest.
[Editor’s note: For more blog posts on CSTEP’s experience dealing with think tanks’ decisions read Acknowledging a prominent think tank: the Center for Study of Science, Technology and Policy (CSTEP) in India.]