Identification / Mapping of Slum Environment using IKONOS Satellite Data: A Case Study of Dehradun, India Methodology For the study of slums, Ikonos PAN and MSS Data acquired on April, 2000 and ancillary data like SOI Toposheet (53 J/3), at 1:50,000, 1988 and SOI Guide Map, at 1:20,000, 1982 were used. All the slum pockets identified were transferred to one base map, so as to get an overall spatial distribution and location of the slum area. In order to detect the slum areas, the following factors considered were: Small sized structures with high density; tone difference to get the idea of kachcha or semi- kachcha houses that were obvious in the slum areas; irregular internal street pattern having unmetalled and mostly unpaved; Areas of wastelands, such as on banks of Rivers or Canal, along railway line and road margin were taken as association for identification. The drainage map was prepared based on both Ikonos data and SOI topographical sheets. Case study area was selected based on certain factors and color printouts were taken for detailed field survey along with brief questionnaire. From slum location map and drainage map, slums located in vulnerable areas were marked. (Fig. No. 1 shows the flow diagram of methodology). 
Limitations of the Study Due to time constraint only seven slums out of 113 were taken for intensive study. While updating the slum areas, it was not possible to make detailed map of all the slums .Lack of updated and relevant secondary data on slums was also a constraint. Data Base Creation On the basis of visual interpretation and necessary field survey, the slum location map within the municipal boundary area was prepared. To show the main factor affecting the location and distribution of slums, drainage map had been prepared and slum location map was superimposed on that. In the next step, each and every house was digitized for preparing detailed map of the study area. Data collected on the basis of field survey were transferred to the base map and other maps showing various parameters were prepared. To show the condition of different slums, maps were prepared showing comparison based on the parameters selected. |