www.theinternationaljournal.org> RJSSM : Volume: 09, Number: 10, February 2020 Page 25 Interrelationship Between Brownfield development as a mitigating factor for climate change and critical infrastructure within a metropolis: a case of Kolkata Metropolitan Area Mouli Majumdar 1 and Joy Sen 2 1 Research Scholar, RCG School of Infrastructure design and Management, Indian Institute of Technology Kharagpur, West Bengal , India 2 Head and professor, Department of Architecture and Regional Planning, Indian institute of Technology Kharagpur, West Bengal , India. 2 Professor, RCG School of Infrastructure design and Management, Indian Institute of Technology Kharagpur, West Bengal , India Corresponding Author: Mouli Majumdar Abstract: The growth of an inclusive and sustainable metropolis is motivated by a close interaction between the (i) investment and maintenance of it’s critical infrastructure, (ii) maximisation of the available resources and (iii) incorporation of the technological advances. This growth trajectory is often affected adversely by extreme climate changes like rise in sea level, heat waves, scarcity of food and frequent floods or storms. One of the major reasons for this being the negative impact of climate changes on the critical infrastructure of the city which in turn guides its spatial form. A more compact urban form therefore has positive climate effects of low carbon emissions, more efficient use of energy, reduced environmental costs for infrastructure, more urban green spaces. Along with climatic benefits it reduces construction and operational cost of infrastructure, optimises travel time and encourages interactions creating an environment for innovation. A metropolitan area expanding at the expense of green areas faces the consequence of drastic climate changes like frequent flooding, extreme rainfall, floods etc which further aggravates the problem by depleting its infrastructure. Renewal of Brownfield developments encourages a compact urban form reducing the pressure on metropolitan expansion. Brownfield development discourages urban sprawl improves environmental conditions and has other positive economic and ecological effects. Kolkata Metropolitan Area in this context provides an interesting study opportunity at two levels (i) Kolkata is one of the most vulnerable flood prone coastal cities considering the hydro-geological factors that influence climate changes like cyclones, sea-level rise, and storm surges. (ii) The trend of the metropolitan structure interrelated with its socio-economic condition of Kolkata that is shaped by its physical –environmental setting. The methodology has a bipartite approach of (a) exploring the factors influencing scope of Brownfield development at a metropolis level and (b) influence of the critical infrastructure amongst the factors influencing the Brownfield development on the same scale. KEYWORDS: Densification, Brownfield development, climate changes, critical infrastructure, fuzzy logic overlay. I. Introduction In this century of rapid urbanisation trend, 90% of the expected world’s population growth will be absorbed by the developing world. Most of this urbanisation is expected to be in Asian and African countries (United Nations, 2014; Kotak Institutional, n.d.). This form of urban growth in developing world is not limited to the incremental extension of existing city or the newly planned cities but also urban fragments and corridors growing onto dispersed opportunities or activity nodes. Along with the opportunities from agglomeration of economies, cities today also face multifaceted challenges. These challenges now include climate change induced vulnerability that results in risks from natural hazards and displacement of population. The conventional challenges of accelerating demand in several sectors like infrastructure, housing, and transportation further adds to the pressure. It can be observed that this wave of rapid urbanisation is simultaneous with the rising impact of climate change worldwide because as the cities grow so does its dependency on energy consumption and green house gas emissions. In general there are two approaches observed at city level in response to climate change. One is adaptation that tries to minimise negative effects of the green house gas and exploit the possible beneficial effect (Hamin & Gurran, 2009). The other approach is mitigation that reduces green house gas emissions from the sources and adopts processes or methods to reduce it from the environment.
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Interrelationship Between Brownfield development as a mitigating factor
for climate change and critical infrastructure within a metropolis: a case of
Kolkata Metropolitan Area
Mouli Majumdar1 and Joy Sen
2
1 Research Scholar, RCG School of Infrastructure design and Management,
Indian Institute of Technology Kharagpur, West Bengal , India 2Head and professor, Department of Architecture and Regional Planning, Indian institute of Technology
Kharagpur, West Bengal , India. 2Professor, RCG School of Infrastructure design and Management,
Indian Institute of Technology Kharagpur, West Bengal , India
Corresponding Author: Mouli Majumdar
Abstract: The growth of an inclusive and sustainable metropolis is motivated by a close interaction between the
(i) investment and maintenance of it’s critical infrastructure, (ii) maximisation of the available resources and
(iii) incorporation of the technological advances. This growth trajectory is often affected adversely by extreme
climate changes like rise in sea level, heat waves, scarcity of food and frequent floods or storms. One of the
major reasons for this being the negative impact of climate changes on the critical infrastructure of the city
which in turn guides its spatial form. A more compact urban form therefore has positive climate effects of low
carbon emissions, more efficient use of energy, reduced environmental costs for infrastructure, more urban
green spaces. Along with climatic benefits it reduces construction and operational cost of infrastructure,
optimises travel time and encourages interactions creating an environment for innovation.
A metropolitan area expanding at the expense of green areas faces the consequence of drastic climate changes
like frequent flooding, extreme rainfall, floods etc which further aggravates the problem by depleting its
infrastructure. Renewal of Brownfield developments encourages a compact urban form reducing the pressure on
metropolitan expansion. Brownfield development discourages urban sprawl improves environmental conditions
and has other positive economic and ecological effects.
Kolkata Metropolitan Area in this context provides an interesting study opportunity at two levels (i) Kolkata is
one of the most vulnerable flood prone coastal cities considering the hydro-geological factors that influence
climate changes like cyclones, sea-level rise, and storm surges. (ii) The trend of the metropolitan structure
interrelated with its socio-economic condition of Kolkata that is shaped by its physical –environmental setting.
The methodology has a bipartite approach of (a) exploring the factors influencing scope of Brownfield
development at a metropolis level and (b) influence of the critical infrastructure amongst the factors influencing
on being redeveloped. The range of indicators varies widely depending on the aim of assessment, giving more
importance to health and environmental based indicators or based purely on economic returns. Nevertheless the
most recurring set of 35 indicators can be grouped into following categories of demographic characteristics,
urban structure, probable contamination level, availability of utilities and infrastructure and last but not the least
the probable economic returns from redevelopment of the Brownfield site.
The table number 3 summarizes the final 15 indicators that occur most frequently in the existing literature
eliminating duplicates, redundant or unavailable ones and they are grouped under broad heads of:
socioeconomic, environmental, social infrastructure, and urban environment/infrastructure.
• Socio-economic factors play a major role in prioritizing the sites for Brownfield redevelopment as the idea is
to maximise the economic and social benefits through it. Higher population density and unemployment rate
therefore means a large population might benefit though the Brownfield redevelopment (Chrysochoou et al.,
2012).
• Brownfield are often synonymous with contaminated or probably contaminated lands that may be an
environmental burden. The second factor therefore considers the maximum environmental benefit that can be
achieved through Brownfield redevelopment. The areas with higher permeability and probable contaminated
sites are preferred.
• The next two factors that include urban environment/infrastructure and social are essential for prioritizing
Brownfield areas. It is assumed that a Brownfield is already served by some basic level of physical and
social infrastructure. The urban primary core and areas served by sewer network, water supply, educational
and healthcare facilities are prioritized.
Variables Measurement Category
Population density Population per sq mile Socio-economic
Unemployment rate
Percentage of unemployed people amongst the
labour force Socio-economic
Soil type
Permeable-sand, Semi- permeable- silt,
impermeable- clay Environmental
Proximity to water source or aquifers Aquifer depth Environmental
Presence of flood prone area Availability Environmental
Presence of wetlands Availability Environmental
Threat due to former landuse/
contamination and existence of
environmental burden in official databases Number of probable contaminated sites Environmental
Parks, Open spaces & Recreation Percentage of area Environmental
Access to schools number of existing schools Social
Access to healthcare Number of (Hospitals+ dispensaries+ health
centres+ family planning centres + nursing
homes+ other institutions Social
Access to recreational-cultural-banking
facilities Number of existing facilities Social
Location in urban setting
Classification according to sequence of
development and density
Urban environment/
infrastructure
Transport accessibility
Share of area within walking distance of arterial
road
Urban environment/
infrastructure
Intersection Density Intersection/ sq mile of arterial roads within
urban footprint
Urban environment/
infrastructure
Utility Service Area Access to water supply and waste water
Urban environment/
infrastructure
Table 3: List of variables selected
Reclassifying data within a layer using Fuzzy Membership tool The next step was to get an idea how the Kolkata Metropolitan Area performs when assessed through the factors
of socio-economic, environmental, infrastructure, social. The data was obtained for the year 1991, 2001 and
2011 through various sources and mapped on a GIS interface.
It is followed by an overlay analysis that allowed combining the data to give a single output. The values that
were mapped consisted of various data levels of measure like nominal, ordinal interval and ratio. The nominal or
ordinal scale data (eg: location in urban setting is defined as primary urban core, secondary urban core, suburban
fringe and dispersed development zones) cannot be defined into specific categories but one is preferred over the
other and can guide in decision-making process (MesgariI, Pirmoradi, & Fallahi, 2008). So here fuzzy overlay
function is used which works on fuzzy membership logic in determining the level of confidence that the area is a
preferred for Brownfield redevelopment. The data is therefore reclassified and fuzzy membership function is
used. The values returned ranges from 0 to 1 where 0 indicating low possibility of membership and 1 indicating
Figure 3: The Urban environment/ infrastructure score (for the 1991. 2001 and 2911) If we focus on the urban environment and infrastructure category we observe that South 24 Parganas have
improved and North 24 Parganas have declined slightly for the year 2001 but improved later . Kolkata and Nadia
have more or less has been well serviced with some basic level of infrastructure. Howrah has a stagnant medium
level of infrastructure and has not been able to improve much. Hugli has improved its infrastructure over the
decade of 2001 to 2011. We observe that the Kolkata municipal corporation and its adjoin areas dominates the
region in terms of infrastructure sector showing a primacy behaviour. So scope of Brownfield development
would be more if only infrastructure sector was considered but a combined effect of all the factors show
different results.
Figure 4 : The final Brownfield Redevelopment score (for the 1991. 2001 and 2911)
After overlaying all the four categories we observe that for the year 1991 Howrah and Kolkata had maximum
conditions fulfilled for a Brownfield Redevelopment. In the year 2001,
Kolkata definitely dominated the region with its high levels of infrastructure, population density and social
factors. It also had the highest number of contaminated sites hence it has maximum scope for a Brownfield
Redevelopment. By the 2011 the whole region presented more or less equal scope for the Brownfield