l if e ❯❯ UR B A N i S AT iON By Ankit SikArwAr and ApArAjitA ChAttopAdhyAy
Expansion bEyond limit ahmEdabad Change in land use-land cover (LULC) is a worldwide phenomenon. However, in certain places, the rate of change is expeditious, particularly because of increasing population, huge rural to urban migration and urban growth within a limited space. Ahmedabad is experiencing an unprecedented growth mainly around its periphery.
U
rbanisation can prove to be a gift to human civilisation if it is harmonised and maintained in accordance with the carrying capacity of nature. According to the United Nations Population Fund, the world’s urban population is expected to reach 81 per cent by 2030 (Imhoff et al., 2010). The conversion of rural areas into urban complexes is occurring at an unprecedented rate in the recent human history and thus, is having an obvious effect on the natural functioning of the ecosystem (Turner, 1994). The towns and cities of the developing world are facing unplanned and uncontrolled growth within and around city limits.
urbanisation in India: The Case of ahmedabad
The process of urbanisation in India gained momentum along with rapid industrial growth in the 1970s. There was a further spurt following economic liberalisation and globalisation. Forests were cleared, grasslands razed, wetlands drained and croplands encroached upon under the influ26
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ence of expanding cities, yet never as fast as in the last decade (Rahman, 2007). In 1991, there were 23 major cities in India, which increased to 35 in 2001 and 53 in 2011. Ahmedabad, the seventh largest city in India and the largest in Gujarat, is showing remarkable developmental activities in terms of urbanisation and industrialisation in recent decades. Although not unique to Ahmedabad, the interaction of demographic and economic forces has resulted in a highly segmented spatial pattern of growth in terms of income-class and environmental qualities (Dutta, 2000).
LuLC changes in the last two decades
For the analysis of LULC changes in Ahmedabad, the LANDSAT images from United States Geological Survey (USGS) over three different periods, i.e. 1991, 2003, and 2010 have been used (Fig 1). A significant change in LULC is observed over time. The most significant change is observed in built-up land, which occupied 28 per cent of the total area in Ahmedabad city sub-district in 1991 is increased to 76 per cent of the total area in 2010.
Fig. 1: Land use - Land cover changes over time 1991
2003
2010
The image presents LULC change in the Ahmedabad taluka at different times based on LANDSAT data. The final image is obtained using the Erdas imagine software by supervised classification technique. The pie-diagrams represent the per cent share of different LULC categories to the total area of the Ahmedabad city sub-district.
Map not to scale 1991
Landuse/Landcover categories
2003 50 per cent 30 per cent
28 per cent
50 per cent
Built-up Area Agricultural Land
2010
7 per cent
12 per cent
1 per cent
Vegetation Cover Water Body
4 per cent
Fallow Land
17 per cent
15 per cent
2 per cent
3 per cent
2 per cent 3 per cent
76 per cent
Source: Classified from the LANDSAT images provided by United States Geological Survey (USGS) for 1991, 2003 and 2010.
Population pressures due to huge in-migration resulted in a demand for new residential spaces and modification of older ones. The change in LULC experienced significant negative change in agricultural land, which accounted for 50 per cent of the total area in 1991 and reduced to 7 per cent in 2010. In rural areas, forested land was converted into agricultural land; that later transformed into built-up area (Table 1). The possible contributing factor behind this change has been the penetration of developmental activities from urban areas into the sub-urban and rural areas. The proliferation of new industries and factories along the periphery of the city, also, contributed to the process of land transformation.
Although areas categorised as water body and fallow land comprise a very small percentage of the total area, land use changes regarding these need to be discussed. The area classified as fallow land halved from 1990 to 2010, whereas areas under water body gradually increased, occupying a space of 3 sq km in 1990 to 8 sq km in 2010. This was mainly because of the development of Sabarmati riverfront and suitable management of water harvesting in the vicinity.
role of the population
The population of the city increased from 3.31 million in 1991 to 4.2 million in 2001 and to 5.8 million in 2011 (Registrar General of India, 1991;
Table 1: The area under LULC categories and change over the time Land use- Land cover category sq km Built-up Area Water Body Fallow Land Vegetation Cover Agricultural Land Total Area
71 3 10 44
1991 per cent to total 28 1 4 17
128 6 8 37
Area 2003 per cent to total 50 2 3 15
sq km
sq km 194 8 5 30
2010 per cent to total 76 3 2 12
127
50
76
30
18
7
255
100
255
100
255
100
Change in area from 1991 to 2010 sq km
in per cent
123 5 -5 -14
173 167 -50 -32
-109
-86
Source: Calculated from the classified LANDSAT images provided by United States Geological Survey (USGS). GeoGraphy and you January - February 2016
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Fig. 2: Superimposition of LULC changes and Population 1991
2001
2011
Map not to scale
Superimposed maps of LULC and population. Details: The dot map where one dot is equal to 2000 person is being superimposed on the LULC map to see the similarities in the changing patterns spatially. Source: LULC maps are classified from the LANDSAT images derived United States Geological Survey (USGS), Dot Map for the population trend is based on the Census data provided by Registrar General of India 1991, 2001 and 2011.
2001; & 2011). A precise analysis of population dynamics at the micro-level (village/town) over the last two decades gives us some important insights that link the changes in population and LULC changes over the same period of time. Thematic superimposition of LULC map and dot map of the total population indicates that the population is growing in areas experiencing a significant increase in built-up land in the 20 year period under consideration. There is however, no noticeable change when the male female composition in the built up area is studied. The density of dots is observed to be high over built-up land, whereas the dots are sparse over agricultural and forested land (Fig 2).
endnote
Since the last two decades, the built-up area of Ahmedabad sub-district has witnessed an overall increment of 173 per cent; this has been mainly at the cost of dwindling agricultural and forest land. The changes in LULC as well as in population were mostly seen in Nikol, Naroda, Gyaspur, Vejalpur, and Makarba, situated in the outer periphery of the Ahmedabad city sub-district. The process of change (in LULC and population) has seen a shift from the core to the periphery. The western side of the Sabarmati river has developed in the recent past and experienced significant transformation in LULC and population dynamism as compared to the eastern side of the Ahmedabad city sub-district. For balanced development in the rapidly growing periphery of the sub-district, there is a need for suitable planning that can help reasonable expansion; keeping in mind the limits 28
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to growth. Only then can Ahmedabad experience sustainable growth in future.
references
Dutta, S. S. (2000). Partnerships in urban development: a review of Ahmedabad’s experience. Environment and Urbanisation, 12(1), 13-26. Imhoff, M. L., Zhang, P., Wolfe, R. E., & Bounoua, L. (2010). Remote sensing of the urban heat island effect across biomes in the continental USA. Remote Sensing of Environment, 114(3), 504-513. Rahman, A. (2007). Application of remote sensing and GIS technique for urban environmental management and sustainable development of Delhi, India. Applied remote sensing for urban planning, governance and sustainability. Springer Berlin Heidelberg.165-197. Registrar General of India. (1991). Census of India: District Census Handbook, Ahmedabad. Government of India. New Delhi. Registrar General of India. (2001). Census of India: District Census Handbook, Ahmedabad. Government of India. New Delhi. Registrar General of India. (2011). Census of India: Primary Census Abstract, Gujarat. Government of India. New Delhi. Turner, B. L. (1994). Local faces, global flows: the role of land use and land cover in global environmental change. Land Degradation & Development, 5(2), 71-78. The authors are from International Institute for Population Sciences, Mumbai.
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