Census 2000: The GIS way
There are three dimensions of data and are explained below:
Quantity of DATA
Data is an abstraction of reality because no one needs every bit of data. There may be only percentage of data only if one has all the data useful but one can use the required data only if one has all the data in his possession. In selective collection, it is quite likely that the required data is missed out. So the analogy is to have all the data collected as it is difficult to say at the stage of data collection as to which data will finally be required. But data are costly collect! Apart from collection cost, it is expensive to store and shift through large quantities of unnecessary data. Excess data makes it more difficult to use the data one really needs. Every expenditure of effort that does not contribute to the final requirement detracts because it contains time, effort and resources that could have been used elsewhere to improve the analysis.
Quality of DATA
Quality of dat is the second dimension. The same argument as advanced for selective collection of data holds good for the quality of data. The important characteristics of quality of data are:-
Completeness - Potion of the area of interest
Accuracy - Correctness of data
Precision - Fineness of the scale
Time - Period of validity
Costing - Money spent
The trade off between higher data quality and higher data cost has to be balanced as it always costs more and more to gain less and less data quality.
Data Organisation
The third major factor is the organisation of data. In the current system of tabulated data, the organisation part though critical, is almost missing. It makes the data user’s task difficult and many time misses the quality aspects of data. So far the task of data collection, analysis and dissemination has been going on as part of building Information statistically due to lack of knowledge of better methods of Data Management.
Census Data
Human activities and so is the Census Data are land related. The smallest sub-unit of the land is a parcel. The parcel can only be located by geographic co-ordinates latitude and longitude. Height above mean sea level is the third dimension. The fourth fundamental component to this parcel is time. Next comes the large volume of attributal data collected during Census operations generally at surface level.
During the recent time, census Data has assumed great importance and has lot of commercial value. Its processing, analysing and dissemination has become faster with the availability of high power computing hardware at reasonable price. But this data does not convey about the real world if it is not georeferenced. There is no system in the Census operations where data could be collected map based. The data is collected in statistical formats and use three types of schedules for collecting information, property/parcelwise. The schedules used by Census Department are- House List –Identity, Usage, Head of the Household House Hold-Details of the family individual-includes answers to 23 questions by each individual. A child below 7 years is taken as illiterate.
Though volume of pages are filled with this data as part of these operations but does not reveal the geographical location of the entity and its inter-locational relationship. It is dfficult to understand and give the information about a property by its number and village its name. Even when its Taluka/Tehsil, District and State names are attached, the data remains lifeless as to where exactly it is on the earth in terms of its geographical location unless it is attached to a map.
Geographic Information System
The future, unmistakable belongs to Georeferenced Data Related Information Technology. It is the need of every Government to ensure that all the statistical data collected by various agencies is well managed in terms of its availability to various users in a most acceptable format where one has not to refer other records, documents and maps. It is the GIS technology, which has the answer for the Department of Statistics to improve the efficiency and utility of the department’s role in Data Management System.
Simply defined, Geographic Information system is a computer based decision and operational support technology, highly versatile, designed to efficiently and speedily capture, store, update, transform, manipulate, analyse and display all forms of data and information geo-referenced in plan and elevation modes-User Specific, Location Specific and Time Specific.
Geographic Information System will enable computers to tell us where things are and to which geographic location the Census Data pertains. The whole concept of data will be changed forever. This will not only make Census Data more accurate than ever, but also carries on its glistering, electronic surface a variety of information elements never accessible before and permits their graphical representation in space. GIS will enable not only to the information to geography, but will link the diverse elements of Census operation using the only factor that is unarguably common-the physical locations of the entity, a parcel of land .
The GIS technology will offer-a better system in terms of standards, methodology, collection, data processing and its dissemination. There is therefore need for the Census Department to introduce the concept of GIS in data collection during 2001 Census. It will help them to cover all the parcels and properties with totalperception of the ground reducung gaps I the existing system. The quality of data will be improved, as the shortfalls will showup in the system when it is viewed in the GIS environment.
To start with, the department should prepare a strategic plan to create a GIS package villagewise based on existing data using village map updated with the help of Topographical Maps and Satellite Data. This will make the Census operations live with capability of capturing, storing and updating of 2001 Census data speedily. Even of this project is started by end of 1998, it should not be difficult to be ready by the year 2000 with base material of 1991 Census data for conducting 2001 Census operations.
We from ORG GIS had sent a similar suggestion to the Registrar General of India about two months back, but have not received any response. We are confident that those article may evoke interest in that organistion.