Impacts of Extreme Climatic Events on Sustainable Urban Development in Coastal Regions: Selected Case Studies of India

Abstract

Unequivocally, it is now evident that the earth’s climate has been changing with significant impacts on various counts and magnitudes. This is more prominent during the recent decades of the Anthropocene Epoch when extreme climatic events are occurring quite frequently, often leaving their irreparable imprints on contemporary human civilization. Given the trends of global warming under business as usual, it is expected that the higher reprehensive concentration pathways (RCPs) will be the reality to impoverish the vulnerable ecosystems, including human habitats. The change in thresholds of human adaptations in different geographic regions will necessitate more investments to recover from climatic hazards and disasters. As the countries, especially of the global south, is going to accumulate more people in the urban locations, extreme climatic events in the form of air pollution, urban heat island (UHI), urban drought, water scarcity, thunderstorm, cyclones, high-intensity rainfall, urban flooding and water logging, etc. are anticipated to jeopardize the urban environments with the consequence of increasing physical and social distresses to the inhabitants.

In India, the rate of urbanization is still low, but the human population concentrated in urban centres is significantly high. Consequently, inadequate infrastructural facilities and amenities available to a greater section living on the edges, and threat to life and property to a sizeable number of population of the country are inevitable. As per records, urban areas situated in the coastal regions of the country, under the humid tropical environment, are becoming more vulnerable to extreme climatic events. Although improvement in weather forecasting systems has enabled the administration to reduce loss of life, the recurring hazards as stated earlier are incapacitating the day-to-day functions of the urban ecosystems in which the poorer section of the society is the principal victim.

In this study, the prominent urban centres of both the east and west coasts of India have been selected, where a moderate climate is expected all year round due to the land-water interface; however, in recent times, these areas are experiencing extreme climatic events or hazards. Moreover, as these locations accommodate large concentrations of population, an assessment of their climatic hazard potentials needs to be studied for sustainable urban development that is both resilient and inclusive. The exercise will attempt to explore how climate change is responsible for enhanced extreme climatic events, leading to the adversities in the urban ecosystems of the coastal locations, and what mitigation, as well as adaptation strategies, may be recommended as appropriate to overcome the situation under various time windows. The analyses will be mostly done based on the review of published works of literature and recorded data, besides extensive use of satellite-based remotely sensed weather information available from various authentic sources.

Introduction

The terms ‘climate change’ and ‘global warming’ are now used almost interchangeably (Nda et al., 2018), although climate change refers to the change in weather phenomena by natural and anthropogenic causes (Swain et al., 2020) and global warming relates to human-induced earth warming (Vogel et al., 2019). The surface temperature has risen by 1.09 °C between 2011 and 2020 compared to the last few decades (Nagai et al., 2020). The number of cold days and nights has decreased and warm days and nights have increased (Toros et al., 2019). The global weather pattern has been oscillating over the last century in a systematic mode, but the contemporary rate of climate change is distinctly more rapid due to the ever-increasing of greenhouse gases (mostly carbon dioxide and methane) from the urban and industrial centres into the atmosphere.

Indian Coastline and Climatic Hazards

As the earth–atmosphere complex feedback mechanism is accelerating over spatio-temporal scales (local to regional), the various dimensions of the present climate system are rapidly changing, especially with the occurrences of extreme climatic events and their increasing frequencies as well as intensities across the South Asian region, especially surrounding the Indian subcontinent (Mandal et al., 2022). The geography of the Indian subcontinent has a unique distribution of land and sea in which the peninsular landmass protrudes towards the Indian Ocean, making it seem as if the two arms of the Indian Ocean, namely the Bay of Bengal and the Arabian Sea are projecting towards the north (Hijioka et al., 2014). Although much of the region is lying north of the Tropic of Cancer to signify its extra-tropical regime, the presence of the gigantic Himalayas, running for almost 2500 km with an average altitude of 4–6 km, has separated India from the Asian mainland, thereby giving this subcontinent a more monsoonal climatic character. The continental and maritime landmasses of the region are both affected by extreme climatic conditions in the form of heat and cold waves, floods, droughts, tropical cyclones, high-intensity rainfalls, etc. However, the ex situ influence of the El Niño Southern Oscillation (ENSO) and the Indian Ocean Dipole (IOD) play an important role not only on the climate of the region but also on the large climate and socio-economic effects worldwide (Ashok and Saji, 2007; Meyers et al., 2007). The coastal cities along the eastern coast of India are in general thickly populated because of the wide extent of the coastal plains, availability of fertile soil and water for irrigation, concentration of settlements and subsequent urban development. On the other hand, the west coast cities usually suffer from the impacts of heat and high-intensity rainfall at different occasions. However, during the last about one decade the trend of cyclonic activity, intensifying to attain greater magnitudes to become severe and very severe cyclones are more common in these coastal regions and the Arabian coastline is increasingly being affected in the recent times due to global warming–induced positive change in sea surface temperature (SST), which is quite evidenced from the recent satellite data.

The Indian coastline, inclusive of the major indentations and island shores, is roughly about 9000 km, while the mainland coast without the estuaries is 6631.53 km. As per the official records of the National Institute of Ocean Technology under the Ministry of Earth Sciences and the National Centre for Coastal Research in 2019, the west coast of India experienced only 27% erosion and 25% accretion while in the east coast 38% of the land area has eroded and 24% accreted over the period of 1990–2016. The lengths of the coastline facing more than 5 m/year erosion or accretion are classified as high zones while 3–5 m/yr. as moderate, 0.5-3 m/yr. as low zone and less than 0.5 m/year change as stable zones. The data shows that the erosion of coastlines is higher than its accretion levels in West Bengal, Pondicherry, Kerala and Tamil Nadu and is negligible in Maharashtra (Table 2.1 and Figs. 2.1, 2.2 and 2.3).

Table 2.1 Shoreline change map along the Indian coast (1990–2016)

Fig. 2.1

Shoreline change map along the Indian coast (1990–2016). (Source: Kankara et al., 2018)

Fig. 2.2

Coastal urban centres of India selected for study. (Source: Computed by the authors based on night-time satellite image procured from https://worldview.earthdata.nasa.gov, dated 5 December 2016)

Fig. 2.3

Status of cyclonic activity in the selected coastal urban centres. (Source: Compiled by the authors based on different government and non-government sources)

In the coastal cities, the main climatic effects are cyclonic storms of different types, intensities and duration associated with thunderstorms and high-intensity rainfall leading to floods and water-logging. Cyclone-induced hazards affect the cities and towns both directly by gusting winds leading to various damages to the infrastructure and service utilities, like transport, electricity, water supply and breaking down of weak structures, e.g., buildings and towers, and indirectly by storm surges, floods, water-logging, with associated man-days loss and health hazards. Other climatic hazards affecting the cities include the thermal impacts of urban heat pockets/islands, severe heat stress (hyperthermia) and the associated health impacts. High temperatures originating from in-situ heat budget or ex-situ heat advections cause severe heat stress to the exposed populations working outdoors for long hours during the summer days. Heat island effects are often found to be caused by the size, morphology and land use and land cover types of the towns and cities. Usually the larger the cities are, the more the chances of heat pockets/islands on the surface, canopy and boundary layer types. To cope with the heat stress, more artificial weather conditioning is required, necessitating more consumption of electricity in the indoor environment. But this eventually leads to an ambient increase of heat generated from air-conditioning machines at the locations of concentration of consumers. This is a cause of discomfort for the population exposed to such artificial ambient heating. In cold seasons, the average temperatures are found to be increasing and with the increase in temperature more moisture in the atmosphere cause blocking of re-radiation through positive feedback. This raises the number of heat pockets even in the smaller cities.

In the coastal areas, there is a two-way local wind system, called land and sea breezes, for which maritime cities are expected to have a moderate climate, but due to accumulation of heat and moisture in the cities, relatively low pressures develop and high temperature continues till late night where ingression of moisture laden winds over the cities increases the temperature and moisture in the city region. This facilitates frequent occurrences of late-evening thunderstorms in the summer months. The pollution load from the urban industrial areas in the form of suspended particulate matter and hydrocarbons also help the development of thunder clouds. These thunderclouds, usually of cumulonimbus type, are characterized by high-intensity rainfall and lightening, causing reported deaths within the city region or its adjoining areas. Heat waves are cumulative weather hazards mostly affecting the poorer section of the people. Under this condition the demand for water is more, leading to occasional water crisis and pressure on municipal water supply services.

The coastal cities and towns of India are now connected through rail and roadways running along the coastlines to facilitate the development and growth of urban centres in between the erstwhile leap-frog development of large urban centres in the region, e.g., the capital cities of the coastal states. Therefore, in many occasions, the urban centres of different sizes and extensions have formed an almost contiguous linear development along the two coastlines of India, both east and west, leading to the formation of urban corridors which have definite impacts on transformation of local climates, and in turn, several impacts of cyclonic hazards on them. The urban corridors thus formed look like a garland on the motherland of India (Fig. 2.4).

Fig. 2.4

Yaas cyclonic activity over the North Indian Ocean region. (Source: https://worldview.earthdata.nasa.gov/)

Cyclones ranging from deep depressions to super cyclones have vast regional impacts due to their extent, damaging potential and associated devastating weather features compared to the other extreme climatic effects occurring in the coastal cities. For example, urban heat islands and heat stress are confined to urban locations only, whereas cyclones jeopardize the regional geographical set-up which requires many years of restoration after the cyclone (Figs. 2.5 and 2.6). It is also found that by the time some recoveries are made against the previous cyclone, a series of subsequent cyclonic events batter the coastal locations including the urban areas, where a high concentration of population accelerates the miseries even though early forecasting with a considerable lead time and some other precautionary measures and reliefs are given to the affected people. Loss of lives has definitely been averted in recent times, but damage to the infrastructure is still very high depending on the nature of cyclones and the entities exposed to them.

Fig. 2.5

Heatwave frequency in the coastal urban centres. (Source: Computed by the authors based on the IMD data)

Fig. 2.6

Flood frequency in the coastal urban centres. (Source: Computed by the authors based on the IMD data)

It is clear (Table 2.2 and Fig. 2.3) that the eastern coast of India is more prone to tropical cyclones than the western coast. The Bay of Bengal creates the perfect condition for the development of tropical cyclones. So, the cities located along the eastern coast of India are more vulnerable to the cyclones. Cities which have emerged along the shoreline are at greater risk. Odisha and Andhra Pradesh are mainly affected by tropical cyclones. Puri, Berhampore, Srikakulam, Vizianagaram, Visakhapattanam and Kakinada are the main affected cities. Even Kolkata, the capital city of West Bengal, which is located nearly 150 km away from shoreline, is not safe from tropical cyclones of the Bay of Bengal. In the recent past, more cyclones hit Kolkata and/or near regions i.e., the frequency has increased. Cyclones also frequently hit Chennai, Nagapattinam, Thoothukodi and Puducherry. Although cyclones hit less frequently in Thiruvananthapuram, the southernmost capital city of the eastern coast, it is notable that the frequency of arrival of cyclones is much less in the cities, located in the southern part of it. Formation of tropical cyclone is much less in the Arabian Sea than the Bay of Bengal; as a result, the cities of the western coast of India, like Panaji, Mumbai, Surat and Jamnagar receives less tropical cyclone and related hazards, but in the recent years devastating high magnitude cyclones have become quite common in this region.

Table 2.2 Major geographical identities of the selected urban centres

The configuration of the coastline, along with the genesis, movement and landfall of the depressions and cyclones of various categories affect the coastal regions of India and its adjoining countries adversely. However, the nature of depressions and cyclones of the Bay of Bengal and the Arabian Sea are significantly different in terms of their number, seasons of occurrence, magnitude and movement leading to landfall; and therefore, the impacts are also divergent at various locations of the country. Usually it is found that the impacts of cyclonic hazards are more along the east coast, and in the states of Andhra Pradesh, Odisha and West Bengal, in comparison to the west coast, especially Maharashtra and Gujarat. In the region in the southern tip of the country, comprising Tamil Nadu and Kerala, the impacts of the cyclones originating from and travelling through the Bay of Bengal are more than those of the Arabian Sea. From a 33-year analysis of cyclonic events and their life-time energy, it is found that the power dissipation index (PDI) is comparatively less in the North Indian Ocean rather than in the Pacific or the Atlantic Oceans, leading to high-energy cyclonic formations around the Indian coastline since 1980s (Patra et al. 2019). Also, the severe cyclones have become widely spaced in the Bay of Bengal over the last three decades with the monthly trends initiating from end of April between the Tamil Nadu coasts and the Andaman and Nicobar islands, which peaks in the last week of May having northern and north-eastern paths. The June to August cyclonic events are few and mainly follow a west and north-west alignment unlike the high-frequency depressions causing recurrent floods in the coastal regions. While the frequencies of severe cyclonic storms slightly rise again in September and end of November, depressions are very few from November to May (Haldar, 2016). It was also observed that even though the frequency and intensity of cyclones increased in the North Indian Oceans, the total deaths and damages are prominently decreasing with better forecasting and warning systems undertaken by the India Meteorological Department (IMD) along with the state governments and the disaster management authorities. Cyclone brings some of the massive disasters in coastal cities like flooding; water-logging situation; damages to agricultural industries, small-scale industries, fishing and public transport systems; food shortages; diseases; loss of lives and wreaths. Cities having a greater percentage of slum population face more difficulties. Cities like Kolkata, Visakhapatnam, Vizianagaram, Machlipatnam and Mumbai which have more share of slum population experiences more difficulties in the context of cyclone and extreme weather events. So, proper planning and development are needed.

Rapid urbanization in the coastal cities across the eastern and western coast of India results in Urban Heat Island (UHI) effects. Urban areas modify the atmospheric boundary layer (ABL) processes as the natural land surfaces are being increasingly replaced by artificial surfaces that have very different thermal properties resulting in urban air to be 2–10 °C warmer than those in surrounding periphery areas (Patra et al., 2017). The urban areas are experiencing enhanced low-level convergence due to mechanical turbulence from rough surfaces, increased surface sensible heat flux and elevated aerosol loading, and hence, urbanization and changes in settlement characters can have a significant feedback on the spatio-temporal patterns of precipitation. This phenomenon is also associated with extreme cases of high-intensity rainfall and heat waves. It has been observed that the number of rainy days and the mean monthly precipitation over Kolkata has significantly increased in the last 50 years (Patra et al., 2017). In India, heat waves typically occur from March to June, and in some cases, even extend till July. On an average, five to six heat wave events occur every year over the northern parts of the country. Single events can last weeks, occur consecutively and can impact large population. Some of the important heat waves in the major coastal cities in India since 1990 are shown in Figs. 2.5 and 2.6.

Climatic Hazards and Coastal Cities

The dynamics of climate change and its impacts on human society are aligned with each other, which differs from one geographical set-up to another. For example, the dry land regions are suffering from excessive heat waves and land degradation, deltaic and coastal region are primarily tormented with catastrophic floods and cyclonic storms, and the inland portion of any country faces extreme summer and winter temperatures. Apart from the different nature of climatic imprints on different geographical sets up, regional resource and their utilization are backed by provincial climatic characteristics. Due to the shifting nature of the monsoon, some of the regions in India have been facing acute water scarcity since the last few decades. Frequent cyclonic storms in parts of the eastern coastal region have become an anxious concern for the planners. In this context, cities particularly in the coastal zones are not only threatened by water-logging and seasonal flood risks, but the uncontrolled urban growth acts like a catalyst that provides the breeding ground of climate change–related adversities in the coastal zone. Effective urban planning and controlled governance prevent unwanted situations where both livelihood and urban ecosystem gets supported. The impact of climate change–related issues is associated with a few elements like calamities, resilience, adaptation and government regulations. The level of vulnerability also relies on certain aspects like how often catastrophic events have occurred and societal perspectives about the storm, along with familiarization of government regulation at community level. Urban expansion and increasing population bring difficulty for policy implementation due to the presence of a diverse range of the socio-culture and economic classes. Most of the million-plus cities are facing weak urban infrastructure which is not equally distributed, and thereby the marginalized communities suffer a lot from climatic hazards.

Among the traditional urban studies, disaster-related research are not being incorporated widely as these are usually considered natural events and are the task of policymakers. Few of the contemporary studies on disaster vulnerability shows how the frequency of disaster and their impacts are primarily triggered by unrestricted urban growth (Dhiman et al., 2019; Nigussie & Altunkaynak, 2019; Kateja & Jain, 2021; Pusdekar & Dudul, 2021; Kadaverugu et al., 2021). The relationship between urban systems and climate change impacts needs to assist through decisive academic assessment to identify allied factors to urban vulnerability and climate change.

Based on this symbiotic relationship between the urban system and climatic hazards, we are primarily focusing on three major sub-themes, namely nature of climate change, how coastal cities are vulnerable to climate change impacts and identification of some of the adaptive measures against climate change–related impacts in the contemporary Indian scenario.

Nature of Climate Change and City Region

Here, the emission of greenhouse gases has been regarded as the main driver of anthropocentric climate change (Vousdoukas et al., 2022) or contemporary global warming. After the Industrial Revolution, the economy shifted from primary to secondary and tertiary sectors (Gleason, 2018), which resulted in increasing the proportion of greenhouse gases in the atmosphere (Liu et al., 2012). In 2019, the total proportion of CO₂ and methane had increased by 48% and 160%, respectively, since 1750, which was comparatively higher over the last 800,000 years (WMO, 2017). The increasing demand for food leads to conversion of forest land into agricultural lands through deforestation, which has been considered as one of the prime causes of global warming–induced climate change (Gomes et al., 2019).

This also includes excessive use of fossil fuels, deforestation that accelerates land degradation, water scarcity and frequent extreme weather events (Ritchie, 2020). Land-use change is not only triggering the emission of greenhouse gases, but the change in cropping pattern also affects local temperatures (Singh, 2020). For example, in Tamil Nadu, degraded forest lands are primarily handed over to private enterprises where oilseed gets promoted (Baka, 2017). This changing political economy is not only restricted to local livelihood but causes regional transformation in weather patterns (Deepika et al., 2020) and depletion of natural resources like groundwater (Kishore et al., 2020). The inputs of climate change may originate from a single pathway, but the outcome of it is spread out in an extensive geographical set-up. In addition, most of the cities (and nations) that face the highest risks from the negative effects of climate change are those with almost negligible contributions to atmospheric greenhouse gases (Zheng et al., 2019), as the intensity of the impact depends upon the physical set-up and socio-economic background of the region. This observation also holds well in case of some micro-regions of high-emitting countries, like India and China.

Among the different geographical set-ups, cities are likely at greater risk for the consequences of climate change. This risk factor is not only due to the high amount of greenhouse gas emission from the city region but also due to their associated socio-cultural components, nature of governance and overcrowded population pressure creating an unfavourable situation to tackle the effect of climate change. Coastal regions are dynamic due to their unique geophysical ambience and growing concentration of human settlements (Douben, 2006). Moreover, the coastal zones are open to receiving the first blow of climate change impacts. Throughout the globe an average of 46 million people per year experience storm-surge flooding. This number may increase due to the exceeding rate of coast-ward migration of population all over the world (Balica et al., 2009). The developing nations, like India, are facing the biggest challenge due to climate change-related impacts over poorly developed infrastructure in many areas.

Climate Change and Vulnerability in the Coastal Cities

The impact of climate change on human livelihood depends on man–nature coupling within an environmental set-up. The massive influx of rural population in surrounding urban centres, demand for urban amenities, presence of environmentally degraded areas, and faulty infrastructure make the urban population extremely defenceless against extreme weather events. Till 2010, about 30% of people in India were residing in urban centres (Census of India, 2006). Owing to rapid urbanization and prevailing pulling factors from surrounding regions, Indian cities are experiencing rapid population growth. On estimation, about 70 Indian cities will accommodate more than 1 million population by 2025 (CSO, 2006). Three mega-urban regions, namely Mumbai–Pune (50 million), the national capital region of Delhi (more than 30 million), and Kolkata (20 million) will be among the largest urban concentrations in the world (Conservation Action Trust, 2006). In this context, the Intergovernmental Panel on Climate Change (IPCC) has noted in its overview how the rising amount of precipitation may cause a tremendous vulnerable situation for the cities in the global south (EM-DAT, 2010). Flood-related deaths have increased threefold from 1960 to 1990 (Dasgupta et al., 2013). The climate change–related issues or weather events and changing patterns in cities or urbanization create a contiguous system where one causes the other. The vulnerability of cities is much dependent on their geographical set-up, where coastal cities are regarded as very much threatened by climate change-related adversities. In many such cities, flooding and cyclonic storms are common phenomena that turned into a disaster due to unplanned growth and unsatisfactory infrastructural facilities, even though coastal cities like Kolkata and Mumbai experience overcrowded slum populations which experience negligible backup to prevent environmental threats (Roy & Sharma, 2015).

The climate change–related changing weather pattern has its widespread impacts. In India, the nature of climate change is primarily connected with temperature and precipitation, including the following factors: (1) increase of mean annual and monthly temperature (by 2–4 °C); (2) variability of monsoon rainfall, where some regions experience high rain and some regions experience low rain; (3) the number of rainy days decreases and about 50% of monsoon rainfall occurs within 15 days, thereby increasing the number of high-intensity rainfall days; (4) the regional temperature rise is the factor behind the fragile ecosystem in central India (dry land), where 5–10% of rainfall is declining. This changing weather pattern has a great impact on the coastal cities in India in multiple ways. Considering the climatic vulnerability perspectives, it is observed that cyclonic and coastal flooding largely affects the urban centres of Kolkata, Mumbai and Chennai and frequently causes mass destructions to the cities of Visakhapatnam, Surat, Bharuch, Bhavnagar and Jamnagar, even though the Bay of Bengal sector is far more prone to such hazards than the Arabian Sea (Mishra et al., 2021; Bhardwaj et al., 2019). A sea level rise of between 30 and 80 cm has been projected over the century along India’s coast affecting the regions around Gujarat, Mumbai and parts of the Konkan coast and South Kerala, as well as the deltas of the Ganga, Krishna, Godavari, Cauvery and Mahanadi. The low-elevation coastal zones on the western coastal region are more vulnerable than the eastern coast (Stern & Stern, 2007; Saintilan et al., 2020). In the recent years, the coastal metropolitan cities like Mumbai, Chennai and Kolkata have seen the ravages caused by urban flooding over long durations (Prasad & Singh, 2005; Malik et al., 2020). Another associated hazard of these urban centres is the problem of scarcity of safe drinking water and consequently water-borne health problems (Revi, 2008; Maity et al., 2018). Such risks greatly affect the economy of the region (Heger & Neumayer, 2019).

A major group of disaster studies has considered geographical location to be the main factor for climatic risks (Bai et al., 2018; Hobbie & Grimm, 2020). The coastal zones are considered as being the most vulnerable to cyclones, floods and tsunamis (Sinay & Carter, 2020). Apart from the location-specific factor on climatic hazard, another group of scholars has considered the social and economic status that causes different scales of vulnerability and risk factors mainly in a coastal city (Friedrich et al., 2020; Chan et al., 2018). Song et al. (2019) argues on location-specific factor and considered the level of resilience and different adaptive measure that are responsible for tackling the risk factor. Hari et al. (2021) have shown how marginalized people always become highly vulnerable during the storm or even its aftermath effect (Mehta et al., 2019). In many disaster-related literature, urban study and urban governance are considered the prime factor that tackles the risk factor by improving urban infrastructure, which on other hand, can be related to resilience and adaptation of the region (Dhiman et al., 2019; Singh et al., 2021). Therefore, there is not a single predominant element responsible for disaster risk in a coastal city; rather the combination of factors provides the foundation that makes coastal cities in India at risk. Based on the available literature, we are primarily focusing on five major factors which are associated with climate change-related disaster and risks. Most of the low deltaic and coastal areas are attaining high risk for climatic hazard (Grases et al., 2020), where the relatively wealthy community can bear the cost of hazard and revive quickly, while the poor communities suffer much due to already existing challenges in their livelihood (Sinha et al., 2021). In this context, Idris and Dharmasiri (2015) have advocated socio-economic integrity as a survival strategy for reducing the risks. Type and magnitude of disaster matters, e.g., large-scale disasters like tsunami and cyclones are riskier than local floods (Chittibabu et al., 2004; Gupta et al., 2019). Resilience and adaptation depend on the level of awareness about the events and community-level solidarity to match with the relevant government policies (Tajuddin, 2018; Dhiman et al., 2019; Singh et al., 2021). Therefore, to minimize the risks, integration between local, state and central governments, and adequate budgetary allocation for the geographical fragile areas along with equitable distribution of facilities are also very important (Singh et al., 2021; Chu, 2018).

The unprecedented urban growth in the large cities in South Asia accelerates the intensity of storm-induced calamities, where the urban population increases by 140,000/day (Fuchs, 2010). More importantly, this growth has become quite extraordinary in the port cities. The port side location provides high-risk factors through cyclones and floods. Even low-intensity storms become deadly for the community which is near the coast. For example, in India, Kolkata and Mumbai are ranked first and second where about 14.0 and 11.4 million of the population, respectively, are estimated to be vulnerable to coastal flooding in the upcoming years (Fuchs et al., 2011).

Resilience Against Vulnerability in Coastal Cities/Regions

The concept of vulnerability is connected with the 1970s environmental movement (Kroll-Smith et al., 1997) which denotes the ecological perspective of disaster and how much exposure the community is facing against a particular risk (Trickett, 1995). However, a group of scholars have considered the relative nature of vulnerability that depends on human perception (Heijmans & Victoria, 2001), as people act differently within the same set of environment due to their socio-cultural and economic individuality (Kollmuss & Agyeman, 2002). This dissimilar behaviour depends on wealth, social integration, cultural contrast and knowledge about that single environment phenomenon. Vulnerability or exposure to the disaster is conceptualized as the natural state of being (Ewald, 2002). The terms ‘vulnerability’ and ‘risk’ are often interchangeably used where ‘risk’ denotes anticipated losses from a particular hazard to a certain element(s) at a particular point of time in the future (Cardona, 2005). In climate change vulnerability research, two particular sets of vulnerabilities are yet to be properly addressed, one is the bio-physical vulnerability and another one is social vulnerability (Nyong et al., 2008). The biophysical vulnerability denotes the ultimate collision of a hazard effect, whereas social vulnerability denotes the response of human society to the shock (Vincent, 2004; Nyong et al., 2008). Ghosh and Ghosal (2021) show how different socio-economic backgrounds in the urban sector make unparallel risk factors during the storm. In most of the cases, marginalized or migrated people from the surrounded rural sector (and/or urban poor) are concentrated in economically and environmentally weaker zones of the city (Mukherjee et al., 2021). Affluence allows individuals and households to diminish risks factors; for instance, by having safer housing, choosing safer jobs or locations to live in, having assets that can be called on in emergencies and protecting their wealth by insuring assets that are at risk (Sinha et al., 2021). Generally in the urban sector, optimum sites which are less vulnerable to risk factors are primarily distributed to the wealthy communities, because they can afford the rent. Whereas low-income groups are far away to make their choices and as a results sites that are vulnerable to risk are distributed to low-income groups (Picciariello et al., 2021). For example, in the Sundarban region, cyclonic storm is a yearly event wherein an average of two or sometimes three cyclonic storms are common each year (Bhui et al., 2022). This is why for decades the primary activity in the Sundarban region gets distorted (Ghosh et al., 2018). This results from the working-age males migrating to surrounding urban centres (Kolkata and Howrah), and leaving women to take care of their families. This is how within the same set of environmental condition women and children becomes much vulnerable (Jalais, 2010). Considering the religious and cultural contexts, indigenous communities and Muslim-dominated portion of damaged sectors are exaggerated the most (Bardsley & Wiseman, 2012). For example, in the case of the Sundarban region, isolated islands are affected most by cyclonic storms particularly inhabited by indigenous people (Mehta et al., 2019). In big cities like Kolkata and Mumbai slums are being considered as the worst site for habitation due to degraded environmental settings primarily occupied by the marginal Muslim community (Das et al., 2021). Apart from the different human societies, there are the following elements and populations which are at risk due to climate change vulnerability: (1) slums and squatter settlements along with migrants from a rural sector (Ramesh & Iqbal, 2022); (2) urban ecosystem through the damage of wetland and canals (Chaudhuri et al., 2022); (3) high rise buildings which are explicitly vulnerable to gusty wind flow during cyclones (Revi, 2008); (4) daily workers and commuters (Rumbach, 2014) and (5) risk on urban basic amenities like drinking water, delivery system and associated services.

Three major factors that drive the intensity of vulnerability to society are exposure, susceptibility and resilience. Where exposure and susceptibility are the prevailing risky condition within the system, resilience is the capacity to adapt or recover from the risk (Balica & Wright, 2009). Here, exposure is the progression that estimates the intensity of any storm event (Balica et al., 2009). Fekete (2009) noted that exposure is the measurement of the vulnerable element within a system, while Penning-Rowsell et al. (2005) defined exposure as the likelihood of human and environment. On the other hand, susceptibility is the degree to which the system gets affected (Smit & Wandel, 2006). It is unavoidable that the susceptibility or sensitivity varies from place to place, therefore it is relative. The concept of susceptibility is still under process and yet to get mature. Hence, the perspective of susceptibility is debatable and creates misconception between the social scientists and physical scientists. Resilience acts like an intermediate for reducing risk factors as it is the method to take on some measure to tackle the effect and bounce back to the previous state (Tanner et al., 2009).

Resilience is the adaptive capacity by people and government to prevent negative consequences of climate change or any natural calamities. Capacity refers to the total strengths, attributes and available resources that society, community, or organization possesses to cope and decrease the risk from disaster and increase resilience (UNISDR, 2017). A culture of resilience could develop if we can enhance the disaster risk reduction capacity of individuals as well as organizations. On the application or the procedure to make an effective resilience or adaptive tool, different scholars put the diverse range of perspectives. For instance, Sterr et al. (2000) represent the process of coastal city resilience through maintaining the consecutive steps, namely protect, retreat and accommodate. Maintaining this synchronous procedure needs to incorporate proper governance. In this view, Revi (2008) points out how the adaptive measures of climate change need to assist through various scales (national, region, city and local). Patnaik and Narayanan (2009) pointed out a group-specific capacity-building approach, specifically among the poor community in cities, as they suffer the most. Focused group capacity building is regarded as the best possible way due to the over-concentration of marginal communities in the Indian cities. Muneerudeen (2017) considers rapid land-use change as the prime cause to enhance regional vulnerability in coastal cities through flooding. This needs to be supported by local adaptation strategies with the consideration of socio-ecological resilience (Tajuddin, 2018). Roy (2019) considered coastal infrastructure development which can cope with the dynamic nature of weather phenomenon without compromising the socio-economic activity of the commons. The perception of resilience can be divided into multiple-element within a system or geographical set-up. In this point, Di Mauro (2006) has considered analysing the pattern of resilience into the fourfold segment, i.e., political, administrative, environmental and social organizational.

Suggested Adaptive Measure to Tackle Flood and Cyclonic Risks in the Indian Coastal Cities/Regions

Among the different types of climatic hazards, coastal zones are primarily affected by cyclones and floods (Sundaram et al., 2021; Malakar et al., 2021). Scientists have suggested various adaptive measures against cyclonic storms and related flood hazards for different specific regions of the coastal states. Samaddar et al. (2015) and Chatterjee (2010) have prescribed Yonmenkaigi System Method (YSM), which is the capacity building method for community implementation of participatory approach called ALM (advanced locality management) in case of Mumbai; while Agnihotri and Patel (2008) are in favour of flood water detention pond, for the diversion of flood water to other rivers in Surat. In case of Cochin, Thiruvananthapuram, and Kottayam, infrastructural development, river basin management dam restoration and formation of flood emergency action team (FAAT) are some of the viable options (Sudheer et al., 2019). For Udupi and Mangalore, infrastructural development (Roy, 2019) and interlinking of rivers for water sharing to mitigate floods (Chakraborty, 2021) are advocated. Chong et al. (2018) have suggested eco-tagging and text-mining techniques to boost the resilience among communities, whereas Samuel et al. (2018) argued in favour of locality-specific cultural green social work for Chennai. The situation of Visakhapatnam and Machilipatnam are favourable for strengthening rural-urban linkage for the application of the National Cyclone Mitigation Program (Revi, 2008); Integrated Water Resource Management (IWRM) (Kalyani & Jayakumar, 2021) and reservoir and embankment management (Jain & Singh, 2022). In the northern part of the east coast, cyclonic hazards are more frequent and prominent and cause massive devastations; therefore, in case of Puri, Balasore and Cuttack, formation of social capital through the vision of bonding-bridging-linking (Behera, 2021) and restoration of mangroves in coastal areas (Das, 2022) are better options. In a similar context, development of sewer network, drainage infrastructure and financial resources (Dasgupta et al., 2013) and canal and wetland restoration (Saha et al., 2021) are suggested for Kolkata; besides mangrove restoration (Erwin, 2009), polder land management (Sung et al., 2018) and embankment management (Paszkowski et al., 2021) are advised in the Sundarban deltaic region where the cyclones first strike before its way to the Kolkata megacity region.

Conclusion

Although the share of urban population to total population of India is still low compared to the global north, the urban centres are increasing rapidly in terms of their total population and urban infrastructure development on both horizontal and vertical scales. The cities and towns of the coastal region of the country are no exception. During the last three decades, such urban centres have been witnessing climate change related to extreme weather events particularly in the form of heat stress and cyclone-induced hazards. Different adaptive measures as suggested earlier in this chapter need to be implemented on priority basis to tackle the problems in the near future to reduce the vulnerabilities, especially among the risk-prone sections of the society.