Summary

Background

Geographic Information - We need geographic information to identify features, people, or any natural phenomenon on the surface of the earth. At a basic level geographic data comprises location (where is it?) and descriptive or attribute information (what is it?)[1].

Knowledge of the location of features allows distances to be calculated, maps to be made, directions to be given, all of which are vital for sound decision making. Also, the knowledge of the location of an activity allows it to be linked to other activities or features that occur in the same or nearby locations which may provide insights on trends, relationships between activities[2]. This approach has become a powerful tool in understanding, analyzing and managing the world we live in and opened the stage for Geographic information systems (GIS) technology.

Geographic Information System (GIS) - The GIS technology is a hybrid product of computer science, engineering, cartography, and digital data acquisition, image processing and graphic sciences. Today, many more fields of knowledge such as natural sciences, economics etc have contributed to the technology making it an even more powerful tool for decision making. But what really is GIS?

According to ESRI, the leading company in GIS software solutions, a GIS integrates hardware, software, and data for capturing, managing, analyzing, and displaying all forms of geographically referenced information[3]. The US Geological Survey provides a similar definition but expands it by including the procedures, operating personnel, and spatial data that go into the system as part of a GIS[4].

While other database systems may offer similar functions of capturing, managing, analyzing data etc, one element that distinguishes GIS from such systems is that it is based on spatial data. Attribute information such as demographic data must be geo-referenced (given a location connection) before it can be used in a GIS. That almost all information can be geo-referenced was one of the key drivers towards the development of the GIS technology.

The power of GIS lies in its unique integration capabilities.  GIS allows disparate data sets from various sources to be brought together in a single system thereby offering a consistent framework for analyzing geographical data. In this way it reveals relationships, connections, and patterns that are not necessarily obvious in any one data set, enabling organizations to make better decisions based on all relevant factors[5].

Today, GIS is being used in virtually all sectors of development and is helping thousands of organizations and individuals answer the “what”, “where”, or “what if” questions of their businesses.

Spatial Data Infrastructure - Mostly organizations or individuals who use GIS need to integrate data from multiple sources, organizations, and formats. While this unique integrating capability makes GIS a powerful tool it may also pose a big challenge. Obtaining data from multiple sources or organizations demands good collaboration along the supply line; integrating multiple formats calls for interoperable systems and standards; and good GIS results can only be produced by well trained personnel. Creating an enabling environment to overcome these challenges and make GIS a powerful tool as it should, is the goal of spatial data infrastructure (SDI). Without it, meaningful application of GIS is not possible.

The term “Spatial Data Infrastructure” (SDI) is often used to denote the relevant base collection of technologies, policies and institutional arrangements that facilitate the availability of and access to spatial data. The SDI provides a basis for spatial data discovery, evaluation, and application for users and providers within all levels of government, the commercial sector, the non-profit sector, academia and by citizens in general.

From the above definition the main emphasis of SDI is the bringing together of various spatial data held by various stakeholders and facilitating ready access to this data.

Benefits of SDI - Implementation of SDI comes with a number of benefits. Among the salient ones is:

• The provision of timely access to reliable, consistent geospatial data to support sound decision making by local, regional and national governments. 
•  The minimization of the waste of resources on duplicate activity. Through SDI institutions collaborate on a number of policy issues and also share spatial data. Institutions are aware of the available data and would therefore not collect existing data. This maximizes the return on investment in spatial data. 

•  The maximization of datasets integration due to use of common standards. Use of one standard makes all stakeholders adhere, for example, to the set file formats, accuracies and data documentation. 

•  The improvement of the quality of information and services offered by government agencies and private sector due to the collective participation of many stakeholders.