Production of and trade in commodities are the bases of the economy of any country. For these to go on, smoothly and with efficiency, the most basic need is the information exchange. The amount of information exchange depends very much on the economic development. With the increase in demand for more information and exchange, the means of exchange also develop. Letters are a vital element in the exchange of information for long. The means of transport of letters depend on the distances to which they are transported. For short distances, they are sent through the roads. For distant places, they are sent by the railways. And for still farther distances, they are sent either by sea or by air.
Speedposts and the letters that should reach in a short while are being sent through the air. Until now, letters were carried in India by the Government Department alone. Now, there are private courier services, too. The Government Postal Services have introduced 'speed post' to facilitate quick delivery of letters to distant places. Information exchange is not only through letters but also through various other means such as the telephones, electronic equipments such as the telefaxes.
In sum, people, products and information are transferred through roads, postal services, sea routes and airways. Transfer is done through one or more of the transport modes. Therefore, there is a competition between the carriers or interdependence among them. As such, development in one leads to developments in another. This is because there are merits and demerits to each of these transport modes and vehicles.
What are their impacts? How did they make for a change in geography? What developments occurred in geography as a result of these changes?
These have ushered in new perspectives and paradigmatic understanding in geography. In the 1950s, for example, number and quantity brought in a scientific revolution in geography. Measurements and gathering of statistical data for understanding the world and to resolve problems that face the earth had become day-to-day activities. In course of time, mapping, cartographic research and mathematical methods have come into use. In the beginning of the 1960s, there were several descriptions and explanations which have now become established geographical ideas.
Continuous developments in information technologies, increased field based activities, voluminous data collected at the local and regional levels, the use of computers and mathematical algorithms - all have impacted to increase the information manifold. Information has multiplied ten times, hundreds of times and million-fold. In order to take advantage of the exploding information, there came other, forward looking developments during the 1970s and 1980s. Although remotely sensed data have been received from the aerial photographs even before, satellite images have now supplemented even better information. The traditional tool of cartography has now provided support in integrating human skill with the computing skills of the computers and this has developed into the modern geographical information systems.
Computers have now turned into devices, directly storing data from the fieldwork. They have now become not only the instant processors of arithmetic solutions and maps but also print them out as hard copies.
Space and satellite telecommunications, manual and computer mapping technology and analytical mathematical algorithms have all been pooled to provide us with the Geographical Information Systems (GIS) that could accommodate and meet with the challenges of information explosion in the world in the 1990s. In several western countries, hundreds of the GISs have come into use. It is estimated that there is now a total of 2,000 such GISs in use in the world. They have already been in intensive use in the departments of development and management. They have come into use, in our own country as well. In the wings of Survey of India and in the Departments of Universities, they have now been used to the extent we could cope with the information explosion.