Preparation of Base Map and ELU
Base Map
The basic prerequisites for a "Development Plan" is the preparation of a base map indicating the limits of the planning area, along with important physical features such as existing roads, water bodies, hillocks, contours, etc. The base map was prepared with the help of remote sensing satellite imageries, obtained from NRSA Hyderabad. Every built-up land feature having dimensions more than 3m x 3m was recorded and mapped to facilitate proper planning of the area. Accordingly a combined base map of the planning area, to the scale of 1: 5000 was prepared on the basis of the details recorded from the satellite imageries. For the purpose of showing built-up area on the base map both from village Gaothan and outside, a detailed survey based on plane table and total station technique was carried out. The cadastral details about the property boundaries obtained from revenue village maps, showing survey numbers or gat numbers (S. Nos. / Gat. Nos.), were also superimposed on the base map, duly verifying their correctness with the help of suitable ground control points.
Satellite images of IRS 1C and LISS-III were procured from NRSA for the PCMC region. Various features such as rivers / streams, water bodies, forests, agricultural lands, barren lands, limits of settlements etc., were extracted from these images. The extraction process made use of latest classification technique. Required numbers of ground checks were carried to determine the accuracy of classified features. Any modification, if required, was then done. The output of these processes has culminated in the classified land cover map. From the satellite imagery various congested pockets within the village were identified for the purpose of detailed survey. The classified land cover map was integrated with the base map, which is the first step in preparation of the Existing Land Use map.
SOI toposheets of 1:50,000 scale were procured from the maps division of SOI, Pune. These maps were digitised to the GIS-compatible format. The maps were then integrated with each other and area of interest was extracted. This formed the initial base map and helped in registration of satellite images and incorporated the features from the cadastral and village maps.
Maps of the newly merged 18 villages were procured from the District Inspector of Land Record (DILR) Office. The scale of the procured maps was 1:10,000. Maps of the regional plans were also collected from the Town Planning Office of Pune. The Sanctioned regional plans for the Pune District was also collected from the office of the Assistant Director of Town Planning.
Approach and Methodology
Based on the input data available and the review of the data, the following approach has been followed for various activities under the scope of preparation of base map / ELU map.
The planning area was studied using Survey of India (SOI) toposheets. The SOI toposheets no. 47 F/10 and 47 F/14 on 1:50,000 were procured from SOI for planning work. Initial field visits were conducted to study the general topography of the area. SOI toposheets no. 47 F/10 and 47 F / 14 were scanned and digitised for the following features:
- Latitude / longitude grids
- Contours
- Road network
- Railways
- Village polygons (for 18 villages)
- Village names
- Rivers and streams
- Ponds / Lakes.