Dr Satyaprakash
Project manager, GIS and GPS
Centre for Spatial Database Management and Solutions,
Noida, India
[email protected]
| Different surveying techniques have been used in the past for mapping the land of the villages and also to map the houses and other features of the village. Each technique has its own merits and demerits, and it has been found that not one technique is able to give a complete solution to the problem of mass mapping of villages. With the advent of space based technologies, it has become easier for the implementers to integrate the data collected through traditional technologies to GIS for better governance. This paper attemts to briefly compare and evaluate two methods of rural mapping, aimed at reducing costs and bringing sustainability in process. |
Rural mapping is as old in India as is the culture of revenue collection or “Lagaan” collection. Even before that, people used to have record of their lands, both in the form of maps and in the tabular form, for the ownership purposes. This mapping has given Shershah Suri a methodical shape to the land record survey for collection of rents. The British continued to operate with the same system of land records for collection revenue. However, it is not only the land revenue collection that is important for present government, but also the basic development of the villages. For that government needs local maps, which are scarcely available. The only maps available in the government departments, are the cadastral map (Patwari/kila map). These maps are available with the Patwari of the village and he has the prerogative of making them available to common man. Besides this, there are no other maps available to the administrators, for any developmental activities. The only other maps available, are the Survey of India toposheets (at 1:25,000 maximum) and village boundary census maps. To some extent, these can act as a reference map, but have not been updated for long. All these have given birth to the need of house level village maps integrated with the cadastral maps.
There can be different methods, which can be used for local mapping, depending upon the accuracy required. Accuracy is a relative term and it costs both, time and money. The accuracy requirement is dependent upon the purpose and user. Absolute accuracy of very high degree may not be required for cadastral and village level household mapping as long as the relative accuracy is of fairly good order. Such accurate maps can be generated through rigorous mapping, using aerial photographs, satellite images, land surveying or low cost devices like hand held GPS with PDA and some field mapping. This paper attemts to compare two methods of participatory rural mapping, aimed at reducing costs and bringing sustainability.
Participatory Rural Mapping
There are different surveying methods, which can be used for mapping the land parcels of settlements. Very few of them suffice the need of modern technology. In the box alongside, the different methods are briefly discussed. In the following parts two different procedures of mapping has been taken up in greater depth. For the preparation of rural maps of the houses and cadastral lands in the village, participatory mode and the use of low cost mapping devices can be used. The experiences and observations of the author, are being listed below.
Method-1
The main steps involved for good accuracy maps can be,
- Acquisition of high resolution satellite images (IKONOS 1m or similar) or Aerial Photographs
- Geodetic GPS and Topographic surveys to obtain Ground Control Points for applying corrections to the satellite images/aerial photographs
- Production of digital satellite image maps and outline base maps
- Digitization of topographic maps, integration of administrative boundaries and updation of permanent features
- Production of preliminary maps from the existing ones and update it from the satellite images/ aerial photographs
- Complementary field surveys
- Integration of survey results in the land information system and production of up-to-date village and cadastral maps
