Contamination of Urban India Environment by Hazardous Industries
There has been a massive population explosion in Delhi during this period. It increased from 4 million in 1970 and 13.7 million in 2001 which was accompanied with massive growth in industrial activities. However due to absence of any zoning regulation or a comprehensive plan for urban development, most industries were located haphazardly leading to overcrowding, traffic bottlenecks and unhealthy living conditions as many industries were located in residential areas.
In 1970 agriculture was predominant in 61.2 % area while built-up land accounted for only 16.8 %. However, by March 2001, built up area doubled to 34.2 % and several large chunks of agricultural land were moved to other sectoral uses causing massive displacement of rural population and forced migration. Table 1 illustrates the trends in land use and land cover in these four metropolises.
Table 1: Change in land use in the metros between 1971 & 2000 (area in km2 )
| | Banglore | Hyderabad | Chennai | Delhi |
| Class | 1971 | 2001 | 1971 | 2001 | 1971 | 2001 | 1971 | 2001 |
| Agriculture | 1984.4 | 905.3 | 1839.2 | 881.1 | 1747.2 | 1324.0 | 16
87.8 | 1188.8 |
| Vineyard | 3.7 | 5.5 | 7.9 | 14.8 |
| | | |
| Built-up
land | 165.6 | 408.0 | 168.4 | 625.1 | 306.5 | 625.2 | 436.7 | 973.4 |
| Reserve
Forest | 320.0 | 328.2 | 235.7 | 233.9 | 178.6 | 168.5 | 15.8 | 15.7 |
| Plantation | 116.7 | 469.7 | | | 164.3 | 360.1 | 23.1<
/td> | 78.5 |
| Water body | 111.3 | 124.8 | 166.2
| 141.3 | 389.5 | 354.7 | 56.1 | 150.9 |
| Scrub land | 359.9 | 263.3 | 438.7
| 934.4 | 219.4 | 170.0 | 374.3 | 299.8 |
| Stony waste | | | 81.0 | 106.4
| 10.6 | 6.1 | 22.6 | 12.1 |
| Total
Area | 3061.6 | 2504.6 | 2937.1 | 2937.0 | 3016.1 | 3008.6 | 2616.4 | 2719.2 |
| Land conversion | - 557.0 | -0.1 | -7.5 |
+ 102.8 |
Table 2 depicts the environmental scorecard with reference to trends in land cover changes and quality of portents of environment, namely, productivity potential, biodiversity, water quality and quantity and organic carbon (OC) content in soil.
Non-point source pollution owing to industrialization
To assess contamination in soil, water and general environment, the study area were delineated into watersheds to specify the direction of contaminant flow and its hazard potential. Bangalore region was demarcated into 10 watersheds with Suvarnamukhi Halla watershed being the largest (155.2 km
2 ) with a maximum number of hazardous industries, i.e., 44 industrial units including 19 of paints and 22 of pharmaceuticals. Spectral reflectance from 37 water bodies spread in the region were assessed and 10 of them were found to be polluted (Fig. 2).