Chapter Three: Literature Review
City and urbanization:
Urbanization is a powerful driver of sustainable development. The higher population density enables governments to more easily deliver essential infrastructure and services in urban areas at relatively low cost per capita, these benefits do not appear automatically and inevitably in development process. So, design & planning of an urban area must not only be functionally and aesthetically attractive to the public, but also environmentally and ecologically sound to be sustainable (Capodaglio et al., 2016).
“Urban design” usually refers to the design of the city and the physical elements within it, including both their arrangement and their appearance, and is concerned with the function and appeal of public spaces. Thus, city and the physical elements as well as the built environment deals with demographic compositions within their land use and transportation systems in an ecological boundary. As the built environment has a design life of over 80 years and settlement patterns & urban form often even far greater, the legacy of these developments will continue to impact the environment now; outline the spatial pattern and long-term vulnerabilities for upcoming decades (Downeset et al., 2014). Decisions made today concerning a city’s infrastructure will affect its sustainability for near future and so, the goal of building resilient urban communities is also closely related to the issue of sustainable development.
Basic dimensions of a city that effects physical activities to a great extent (Handy et al., 2002) are:
1. Density and intensity of development: population, employment, building/floor per unit of area
2. Mix of land uses: relative proximity of different land uses within an area.
3. street network: directness and availability of Connectivity by street.
4. Scale of streets: three-dimensional space along a street as bounded by buildings or other features (e.g., trees or walls, human or automobile- scale, ratio between building heights and street widths, the average building setback, the distance from the street to the building.
5. Aesthetic qualities: Attractiveness and appeal of a place.
According to the above dimensions, there exists basic four interrelated and mostly correlated features / components:
• physical structure / buildings
• transport and
• environment as flora -fauna ; water body.
With challenges of changing lifestyle, foster globalization and institutional transformation, rapid urbanization ; industrialization, environmental degradation, climate change, etc., there comes obvious need of formulate suitable adaptation policies and regulations for urban areas as development control rule or act incorporating above dimensions ; features to guide the development of a city in a planned and orderly manner from the outset.
Researchers generally agree that land use planning is an important tool for reducing losses in natural disasters, helps to become more resilient by integrating ‘natural disaster management’ (hazard mitigation) into overall planning (Sengezer et al., 2005). Building and land use regulation has proven to be the most effective tools for building resilience, reducing disaster and chronic risk in the developed world where resilience is a manifestation of regulatory frameworks that impose a lot of “don’ts” than “dos” which prevent people from building formally (Moullier et al.,2015).
Now a days, as an important consideration of building code, Floor Area Ratio is extensively practiced in developed and developing countries. To accommodate centralization or decentralization of an activity in a particular area or maintain ecological balance, limiting growth and building footprint it is considered an appropriate strategy. For achieving regulations controlling densities of developments, floor area ratio (FAR) is deployed as tools which determines the size of the building in relationship to the size of the plot.
resilience generally refers to “dealing with change” by adapting shocks and stresses (Walker ; Salt, 2006). According to the definition of UNISDR, Resilience is the ability of a system, community or
society exposed to hazards
• to resist, absorb, accommodate to and recover from the effects of a hazard
• through the preservation and restoration of its essential basic structures and functions
• in a timely and efficient manner.
It is also known as ‘bouncing back better’ from any type of destructions. Resilience is characterized by the capability of a system to absorb disturbance, without compromising its structure and function. Resilience concerns include all types of nature and human induced disaster and related economic and social issues. It encompasses a system’s capacity to store knowledge and experience, plan for future change, reorganize without falling into decline, and keep crucial facilities functioning at adverse situation. Resilience should be systemic and integrated into all aspects of development regulation, where policies will develop & provide incentives for compliance (Byahut, 2016).
According to Rockefeller foundation (2014) Qualities of resilient systems are
Resilience can be formulated under mitigation, preparedness, emergency response and recovery. Achieving resilience starts with planning. Measures such as development regulation, land use management, building standards, natural resource protection, property acquisition, critical facilities policies and public education are significant for promoting hazard mitigation. Infrastructure alone will not achieve resilience. Sound development plans that are predicated on disaster risk assessments and land use policies advocating mitigation and preparedness are needed (https://www.aecom.com, 2018).
Researchers identified ‘Nature’ as main source of resilience; where this nature-based solution possessed basic two scheme. In general, resilience could perhaps be more easily obtained by a combination of a few structural (Engineering), and many nonstructural (ecological) interventions, including hydrologic modification (infiltration increase, landscape adjustments, diffuse storage. LID (low impact development) is an approach to land development (or re-development) that works with nature employing principles such as preserving and recreating natural landscape features, minimizing effective imperviousness to create functional and appealing site inventories as a permanent resource rather than temporary intervention tools for resilience. (https://lowimpactdevelopment.org/, 2018).
1. Urban Resilience
Urban Resilience is the contemporary theory and practice for improving the integration of ecology, social science and planning to help cities adapt in the context of change. Urban resilience is typically understood as the capacity of cities to bounce back or even bounce forward from a disturbance or crisis event. On the other way, it is the measurable ability of any urban system with its inhabitants, to maintain continuity through all shocks and stresses, while positively adapting and transforming toward sustainability. A resilient city assesses, plans and acts to prepare for and respond to all hazards – sudden and slow-onset, expected and unexpected (http://urbanresiliencehub.org, 2018).
Unplanned cities are more vulnerable to shock as are ill prepared or unable to recover from negative externalities. Whereas, resilient cities are better able to protect and enhance people’s lives, secure development, foster an investible environment, and drive positive change.
To achieve a transition to a sustainable and resilient urban future, resource use and environmental impacts need to be addressed not only within the urban boundaries, but also by accounting for the dependence of cities on ecosystems, natural resources and people in surrounding areas and other parts of the world. A major challenge for many cities is disaster resilience, which is a strong determinant of urban sustainability (McPhearson et al. (2014).
Urban environments’ dynamics are administrated by continuous transformations due to internal (changing inhabitants’ needs) and external (socio-economic context, environmental conditions and climatic changes) pressures. Achieving a balance among these different, diversified and often unpredictable pressures is one of the key points of sustainable and resilient urban resources planning. There are basic two types of urban resilience according to how resilience can be achieved. Engineering resilience considers systems to exist close to a permanent, stable steady state. Ecological resilience considers the magnitude of disturbance that can be absorbed by a system before this needs to redefine its functional structure by changing variables and processes controlling its behavior (Capodaglio et al., 2016).
Resilience at urban scale:
• Resilient land use:
Development concentrated or encouraged in parts of a city which are by location or circumstance the least vulnerable
Land use patterns responding to existing natural systems
Potential Tools: Zoning, Comprehensive Planning, Incentives
• Resilient infrastructure:
Combinations of grey and green infrastructure designed to both mitigate peak
events and provide other benefits
Potential Tools: Bonds, dedicated resilience funds, PPPs, expenditures via
Capital Improvement Plans
• Well-connected transportation facilities and infrastructure, including transit options and clear evacuation strategies
• Regional cooperation
• Economic resilience: diversified economy
• Social resilience: strong social networks, particularly for communication before, during and after peak events
• Equity: Low income communities are hardest hit by disasters (https://www.ncreif.org, 2018)
Rockfeller Foundation (2015) identified basic 4 dimensions and 12 goals of urban resilience with 52 indicators.
Figure : 4 dimensions and 12 goals of urban resilience
‘Apply and enforce realistic, risk compliant building regulations and land use planning principles’ are in one of the ten Essentials for Making Resilient City Checklist (UNISDR, 2010).