MICRO STUDY AREA


URBAN SPRAWL- MICROLEVEL ANALYSIS
DELINEATION, DATA CAPTURE AND FORMATION OF GRID DATA IN GIS
The geographical area included in the toposheet no 58/B8 of Survey of India between the latitudes of 100 and 10015"North and 76015" and 76030"East which includes the major portion of Greater Kochi Metropolitan Area (GKMA) has been selected for detailed micro level analysis (Map 4.a(i))
This area includes Cochin corporation(Part) and four out of six municipalities of Greater Kochi Metropolitan Area. The municipalities included in the microstudy area are Kalamasserry, Aluva, Angamaly and Perumbavoor. Two major highways are passing through this area namely national highway number 47(NH 47) and Main Central highway ( M.C Road) which connects Angamaly and Perumbavoor.

3km buffer zone
Using buffer function of ArcGIS Geographical Analysis tool a 3km buffer zone on either side of the Highway is created (Map 4.a(ii)).

Built up area 1968
The builtup area 1968 is retrieved from the toposheet 58 B/8 of survey of India . The builtup area retrieved is clipped with buffer polygon to obtain the built up area 1968 of the micro study area (Map 4.b(i)).

Built up area 2002
For the creation of 2002 built up data IRS 1C, LISS III image of the National Remote Sensing Agency has been used. LISS III Image for the study area was classified using the software ERDAS IMAGINE . Based on site verification signature polygons were given to classify the LISS III image. Using the raster to feature conversion capability of GIS the classified built up was converted to polygon feature class which is again clipped with the 3 km buffer polygon created on either side of the highway to obtain the built up area for the year 2002 (Map 4.b(ii)).
Local body wise built up 1968 and 2002
The built up area feature classes for the year 1968 and 2002 are intersected with the local body boundaries to obtain the local body wise built up area for the year 1968 and 2002.(Map 4.a(iii),Map4.b(iii) and Map 4.b(iv)).
Local body wise population density 1968 and 2002
Local body wise population details are collected from 1971 and 2001 publications of Census of India. Population density of each local body was assigned by dividing total population by total area of the local body. Thus local body wise population density maps are prepared (Map 4.c(i0 and Map 4.c(ii))).

Formation of Grid Data
1km* 1km vector grid is created for the Micro Study Area(Map 4.d(i)) to intersect the same with the built up area 1968 feature class (Map 4.b(iii)) and built up area 2002 feature class (Map 4.b(iv)). Thus grid data for the micro study area is obtained with attribute information of built up area and population density (Map 4.d(ii)). Three distance rasters are created for the area namely distance from points (municipalities), distance from CBD and distance from highways(Map 4.e(i),Map 4.e(ii) and,Map 4.e(iii)). The distance values are also added as attribute information in the grid data. Thus grid data pertaining to distance alongwith built up area and population for the years 1968 and 2002 are kept ready for analysis.