Conclusion

Cities’ origins can be traced back to the river valley civilizations of Mesopotamia, Egypt, the Indus Valley, and China. Initially these settlements were largely dependent upon agriculture; however, with the growth in population the city size increased and economic activity transformed to trading. The process of urbanization gained impetus with the Industrial Revolution 200 years ago and accelerated in the 1990s with globalization and consequent relaxations in the market economy. Migration to urban areas pushed the growth of towns and cities with the hope of better living standards, considering relatively better infrastructural facilities (education, recreation, health centers, banking, transport, and communication) and higher per capita income. However, unplanned urbanization leads to large-scale land-use changes affecting the sustenance of local natural resources. Hence, understanding spatial patterns of changes in the land and advance visualization of growth is imperative for sustainable management of natural resources and mitigation of changes in climate. This would help the city planners when planning how to mitigate the problems associated with the increased urban area and population, and ultimately to build sustainable cities.

Bangalore has experienced unprecedented rapid urbanization and sprawl, which has led to large-scale land-cover changes and associated serious environmental degradation, posing serious challenges to the decision-makers in the city planning and management process and involving many serious challenges such as climate change, enhanced greenhouse gases (GHG) emissions, lack of appropriate infrastructure, traffic congestion, and lack of basic amenities (electricity, water, and sanitation) in many localities. Temporal analyses of urbanization using temporal remote sensing data from 1973 to 2016 reveals 1005 percent concretization (or paved surface increase) with a decline in green spaces (88 percent decline in vegetation), wetlands (79 percent decline), higher air pollutants, and a sharp decline in the groundwater table. Quantification of the number of trees in the region using remote sensing data with field census reveals that there are only 1.48 million trees to support Bangalore’s population of 9.5 million, indicating one tree for every seven persons in the city. This is insufficient even to sequester respiratory carbon (540–900 g per person per day). Geo-visualization of likely land uses in 2020 through multi-criteria decision-making techniques (fuzzy AHP) reveals a calamitous picture of 93 percent of the Bangalore landscape filled with paved surfaces (urban cover) and drastic reduction in open spaces and green cover. This would make the region GHG rich, water scarce, nonresilient, and unliveable, depriving city-dwellers of clean air, water, and environment. Major implications of unplanned urbanization are
(a) loss of natural resources
(b) groundwater decline
(c) altered regional hydrology and recurring episodes of floods
(d) enhanced GHG footprint and significant contributions to global warming
(e) reduced carbon sequestration (with the removal of tree cover and water bodies)
(f) alterations in micro climate
(g) heat island formation
(h) escalated energy consumption
(i) mismanagement of solid and liquid waste generated in the region
(j) health impacts (increased instances of kidney failure, respiratory ailments, cancer, etc.)
(k) aggressive behavior of humans (leading to frequent unrest with intra-family and societal conflicts)
(l) domination of anti-social gangs with the fragmented governance of local administration.

Conversion of wetlands to residential and commercial areas has compounded the problem by removing the interconnectivities in an undulating terrain. Encroachment of natural drains, alteration of topography involving the construction of high rise buildings, removal of vegetative cover, and reclamation of wetlands are the prime reasons for frequent flooding even during normal rainfall post-2000. Field investigations (during 2015–2016) of 105 lakes revealed that 98 percent of lakes have been encroached upon for illegal buildings, 90 percent of lakes are sewage fed, 38 percent surrounded by slums and 82 percent showed loss of catchment area. Also, lake catchments are being used as dumping yards for either municipal solid waste or building debris. Indiscriminate disposal of solid and liquid waste (rich in organic nutrient) has enriched nitrate levels in the surrounding groundwater resources, threatening the residents’ health (such as kidney failure, cancer, etc.). Washing, household activities, vegetable cultivation, and even fishing were observed in some contaminated lakes. Multi-storied buildings have come up on some lake beds, interfering in the natural catchment flow and leading to a deteriorating quality of water bodies. Unauthorized construction in valley zones, lakebeds, and storm water drains highlights the apathy of decision-makers while mirroring weak and fragmented governance. This correlates with the increase in unauthorized constructions violating town-planning norms (city development plan) which has affected severely open spaces and in particular water bodies. Large-scale fish mortality in recent months further highlights the level of contamination and irresponsible management of water bodies. Sustained inflow of untreated sewage has increased the organic content beyond the threshold of remediation capability of respective water bodies. Increasing temperature (of 34 to 35 ∘C) with the onset of summer enhanced the biological activities (evident from higher biochemical oxygen demand and ammonia) that lowered dissolved oxygen levels leading to fish death due to asphyxiation. Thus, unplanned urbanization not only contributes to global climate change by emitting the majority of anthropogenic greenhouse gases but also is particularly vulnerable to the effects of climate change and extreme weather. This emphasizes the need to improve urban sustainability through innovation while addressing technical, ecological, economic, behavioral, and political challenges to create cities that are low carbon, resilient, and liveable.

The “smart cities” mission launched by the government in India recently (June 2015) envisages developing physical, institutional, and social infrastructure in select cities with central assistance targeted at improving the quality of life as well as economic visibility of the respective urban centers. Four strategic key components are:
1. greenfield development through smart townships by adopting holistic land management;
2. pan-city development through adoption of smart applications like transport, reuse and recycling of wastewater, smart metering, recovering energy from solid waste, etc.;
3. retrofitting, to make existing areas more efficient and liveable by reducing the greenhouse gas footprint, improving power and treated water supply, improving communication and infrastructure connectivity, and security;
4. redevelopment of existing built-up areas, creation of new layouts through mixed land use, adoption of appropriate floor area index (FAI) considering the level of existing and scope for improvement of infrastructure and basic amenities, which helps in keeping the city’s growth within