The Official E-Newsletter of the Institution of Engineers Sri Lanka   |  Issue 49 - December 2020

Habitats lost by habitats! Coexistence for urbanisation

By Eng. K. K. K. Sylva & Eng. (Dr.) C. S. Bandara

Introduction: The Habitat Agenda for human settlements

“World Habitat Day was established in 1985 by the UN General Assembly through Resolution 40/202 and was first celebrated in 1986” (IISD, 2020; UN Habitat, 2019). It has been celebrated on the first Monday of October, and consequently many activities, events and discussions on urban sustainability take place during the month of October. The purpose of the World Habitat Day has been to replicate or reflect on the state of the basic right of all to adequate shelter and to “remind the world that we all have the power and the responsibility to shape the future of our cities and towns” (UN Habitat, 2019). Many activities related to World Habitat Day have been aiming at human settlements in general. After 34 years of celebration of the World Habitat Day, a review on ‘habitat’ appears to be appropriate. Should we forget the habitat “the natural environment in which an animal or a plant usually lives” (Cambridge Dictionary, 2020) in our discussions?

The Sustainable Development Goal (SDG) 11, of the UN Agenda, “to make cities inclusive, safe, resilient and sustainable” focuses on ‘sustainable urbanization’ and according to UN Habitat (2019), SDG 11 has been called the ‘docking station’ for all the other SDGs. UN Habitat (2019) also states that “by engaging all stakeholders, cities have the ability to harness transformational change and improve the lives of their inhabitants”. Who are these inhabitants? Can we limit these inhabitants to only human habitats in addressing the goals of sustainability? Are the human habits threatening other habitats which may be essential for the sustainability of the ecosystem?

One hundred seventy-one (171) governments have adopted the habitat Agenda for human settlement. The Habitat H II Agenda provides strategies towards a sustainable world’s urban areas (European Environmental Agency, 2020). “Ensuring adequate shelter for all, and making human settlements safer, healthier and more livable, equitable, sustainable and productive” were endorsed by participants at the Second United Nations Conference on Human Settlements in Istanbul in 1996. ‘Adequate shelter for all’ and ‘sustainable human settlements development in an urbanizing world’ have been the two themes of the second United Nations Conference on Human Settlements (United Nations, 1996, p. 12). We try to include the word sustainability in every possible discussion. But are our settlements sustainable? Are human settlements sustainable with a broader ‘biome crisis’ (Hoekstra et al., 2005)?

Do we follow the Agenda Fully?

The goals of Habitat Agenda highlights many aspects: “We recognize the imperative need to improve the quality of human settlements, which profoundly affects the daily lives and well-being of our people”; “sense of great opportunity and hope that a new world can be built, in which economic development, social development and environmental protection are assured”; “human beings are at the centre of concerns for sustainable development, including adequate shelter for all and sustainable human settlements, and they are entitled to a healthy and productive life in harmony with nature”; “development and improvement of shelter that is environmentally sound” (The Habitat Agenda Goals and Principles, Commitments and the Global Plan of Action, 2003). Yes, we are trying our best to provide shelter and adequate infrastructure for human settlements through various programmes. But did we address the parts of “environmental protection”, “harmony with nature” and “environmentally sound” in our process of providing shelter or associated infrastructure for the human settlements? Or, are we forgetting the ‘environmental’ pillar of sustainability in our urbanization process?

What is biodiversity, and why is it important? The lost habitats?

“Human impacts on the natural environment have reached such proportions that in addition to an ‘extinction crisis’, we now face a broader ‘biome crisis’” (Hoekstra, 2005, p. 23). What is this extinction crisis and biome crisis? Does this crisis affect human settlements? An extinction crisis occurs when millions of life forms on the planet earth are getting threatened by any activity. It has come to a situation where humans have become responsible for most of the loss of biological diversity by their overuse of earth’s resources and their activities on the planet. “More than a century of habitat destruction, pollution, the spread of invasive species, overharvest from the wild, climate change, population growth and other human activities have pushed nature to the brink” (The Center for Biological Diversity, 2020). For some of us, the parallel habitats might not exist in our decision-making process! But, if the extinction of other habitats is affecting human habitats, short-term or long-term, then, should we pay our attention to this?

A biome is “the characteristic plants and animals that exist in a particular type of environment, for example in a forest or desert” (Oxford Dictionary, 2020) or naturally occurring community of flora and fauna spreading over a large area occupying many habitats, high biodiversity, sustaining the balance of nature. Biodiversity is defined as “ the variability among living organisms from all sources including, inter alia, terrestrial, marine and other aquatic ecosystems and the ecological complexes of which they are a part; this includes diversity within species, between species and of ecosystems” (Millennium Ecosystem Assessment, 2005, p. 18). Human well-being and the sustainability of the natural ecosystem is highly dependent on the state of biodiversity. But, humans encroaching the biomes without habitat conservation and habitat protection triggers an imbalance in the ecosystem and threatens all life, including human beings on earth. Biodiversity has been considered essential to the sustainable development agenda (Naeem, 2016). But, unless the relationship of biodiversity to human well-being is not explored and science and policy spheres do not understand it clearly the effectiveness of conservation, restoration and sustainable practices will not be effective (Naeem, 2016; Seddon et al., 2016).

Habitat Agenda (2003) is expecting that a new world could be built through harmony and cooperation within and between countries. Economic development, social development and environmental protection, interdependent, but mutually reinforcing components of sustainable development are expected to be realized through effective partnerships at all levels (Habitat Agenda, 2003). Environmentally healthy human habitats should be achieved through the solidarity of all partners of the developmental process considering the environmental pillar of sustainability, simultaneously with the economic and social needs of the developmental process.

What should be an environmentally healthy human habitat?

A sustainable habitat should focus on an ecosystem enriched with survival for all organisms. It should not allow one species to overshoot resources to destroy another organism which is essential for the balance of the ecosystem. It should not allow the production of excess waste that nature cannot degrade by itself through the process of biological control. The humans, if they plan their development appropriately, they could mimic nature to balance the ecosystem. The developmental process should adhere to the in-depth characterization of the concept of sustainability and protect biodiversity.

Ecosystem services will depend on biodiversity. Loss of biodiversity will lead to increasing the likelihood of ecological surprises such as “runaway climate change, desertification, fisheries collapse, floods, landslides, wildfires, eutrophication, and disease” (Millennium Ecosystem Assessment, 2005, p.64). Also, it will lead to undesirable consequences for ecosystem functioning (Turnbull et al., 2012). Turnbull et al. (2012) report that “compared with depauperate versions, more diverse ecosystems appear to utilize resources more effectively and are consequently more productive and stable”. Eventually, a biodiversity loss will affect the provisioning of other ecosystem services such as food and water for all organisms, including humans, since the balance is lost.

What is missing in our planning? Coexistence

Rethinking of the new Urban Agenda (H III), embrace urbanization proposing adequate policies addressing challenges in bridging urban, peri-urban and rural areas while integrating equity to the development plan. It also encourages to verify the effects of sustainable urbanization on sustainable development goals and promotes aligning and strengthening institutional arrangements to ensure effective delivery of the new Urban Agenda.

Sri Lanka, supporting the Agenda (H III), has given deep considerations on social progress in the process of urbanization, while addressing the village reawakening and rural empowerment to strengthen urban-rural ties to retard rural-urban migrations to a greater extent (UN-Habitat III Country Report - Sri Lanka, 2015). Many plans on social uplifting and economic development considerations have been stipulated in the Country Report for Habitat Agenda III. Chapter Two on Land and Urban Planning extensively discusses the methods of ensuring sustainable planning related to the environmental aspects. According to the Country Report “national and regional plans are voluntarily subjected to strategic environmental assessments (SEA) for sustainability and to verify that provisions to mitigate any adverse environmental impacts are included” (UN-Habitat III Country Report - Sri Lanka, 2015, p. 13). It also highlights that “human intervention, environmental degradation, effects of climate change and rapid development activities have contributed to increasing in the frequency of natural disasters” (UN-Habitat III Country Report - Sri Lanka, 2015, p. 13).

The UN-Habitat III Country Report states that in most instances planning in Sri Lanka has been isolated. The non-availability of a complete package of economic, social and environmental solutions, addressing all sectors to improve, allowing viability of local authorities, increased employment levels and reduced regional disparities have been noted (UN-Habitat III Country Report - Sri Lanka, 2015, p. 19). The report also has identified managing the areas designated as risk areas and environmentally fragile areas as the most significant challenge. It has been emphasized that the challenge is to “prevent massive losses of human lives and wasting of colossal amounts in rehabilitation efforts” (UN-Habitat III Country Report - Sri Lanka, 2015, p. 30). But any specific discussions on the loss of biodiversity due to urbanization seem to be lacking in this report or, if not, it has been explicitly identified under ‘environmentally fragile areas’. Any coexistence of the organisms for sustainable urbanization has not been highlighted in this report.

According to Palomo et al. (2013), a significant number of protected areas are becoming isolated, and isolation has been identified as the most critical threat to their conservation. Isolating environmentally fragile zones in the planning process would not serve the requirements of the ecological balance. The ecosystem services will not provide the necessary assistance for balancing through isolated systems. Coexistence will allow a mixture of species outperforming monocultures, with ecosystem functions and their underlying biological processes (Turnbull et al., 2012).

Application of coexistence in urbanization

In understanding the necessity of coexistence for ecological balance and resulting human sustainability, simple methods for coexistence in planning are suggested through this article. If we restrict or barricade underlying biological processes, it could affect ecological balance. A simple change in decision making could allow coexistence in urbanization. This article proposes the following areas for discussion:

a. Identification of connectivity zones

Connectivity zones will allow biodiversity flow through our systems to maintain ecological balance. Preserving areas within human habitats to connect environmentally fragile zones will enable the flow of species across our road networks or built environment. As Figure 1 depicts, the species could move through the connectivity corridors without having a collision with the human habitats. Drainage paths will be the most appropriate zones for flow of biodiversity through cities (human habitats) which is discussed in part c.

b. Use of better approaches in construction to maintain natural habitats intact

The constructions should be limited to identified areas, and they should minimize environmental damage. Constructing houses in hilly areas could be done without damaging the slopes by extensive cutting and filling. Steep slope cuts could trigger landslides. As depicted in Figure 2, the houses in hilly areas could be built to keep natural habitats intact. If the cuttings are essential for construction, rather than covering the slopes with concrete to prevent land sliding, use of natural material to protect the slope will give a better aesthetic appearance while serving many other purposes such as water infiltration and pathways to biodiversity.

c. Use of new concepts mixed with ancient sustainable concepts

Ancient practices have been identified as sustainable, and they have considered ‘whole system’ thinking in their approaches. For example, the water flow from one system has been cleaned before it entered another system by natural water cleaning ponds. These practices will assure pure drinking water for all the species. At present, water is polluted by human activities, and the contaminated water is released to natural water bodies. Contaminated emissions would lead to not only preventing clean water for the other species but their total extinction: the biome crisis.

New concepts such as ‘Regenerative Cities’ could be taken into consideration to build human habitats in a sustainable nature to allow coexistence of a mixture of species. Without concreting draining systems, adequately planned natural drains could be designed in human habitats. This would serve two purposes: infiltration of water to the subsurface and allowing the other species to live in these identified drainage paths. Infiltration of water to the subsurface will prevent excess surface water from the upstream to flow downstream and cause flooding of the downstream areas. Having natural effects in these drains would add beautification to the cities as well. For example, the polluted ‘Meda Ela’ (Figure 3) in Kandy could be created to a biodiversity habitat with natural cleaning plants with a pleasing aesthetic appearance. Examples such as natural cleaning ponds, dry creek landscaping systems could be used to prevent polluted discharge released to a natural water source and subsequently, the downstream.

d. Strong policies and corporation among institutions concepts

SDG 16: Peace, Justice and Strong Institutions is expecting strong institutions with strong policies to support the sustainability of systems (SDG 16: SDG Knowledge Platform). City planning policies should be strong to preserve wetlands or any environmentally fragile areas and areas identified as connectivity zones for the flow of biodiversity to sustain coexistence. Having causally related policies will not be sufficient in the process of sustainable development. For example, in addition to city planning policies, there should be strong policies related to the inflow of harmful material to the system to prevent any unnecessary items adding to the system. Any unnecessary material would make the regenerative process unrealistic. In the case of any essential material to the system, which will not degrade by the natural system, there should be an institutional corporation to regenerate these materials by having appropriately identified recycling plants. Expecting people to collect plastics and bring to a plant located in another city will not be practical, and it should be the responsibility of city institutions to collect such material and distribute to the identified plants for recycling. Strong cooperation of institutions is expected in the pathways to sustainability. Besides, incentives to follow system guidelines for sustainable development should be introduced. If the cost of building according to the guidelines is higher than typical construction, the city institutions should support its dwellers through tax reductions or arrangements of loans to follow the costly but sustainable solutions.

e. Educating the citizens

Education should not be limited to the young generation. All city dwellers should be educated on using human settlements in a sustainable manner. We may tend to make decisions based on our education which may sometimes not be directed towards contextual sustainability. Continuous education of all human dwellers in contextual practices would allow them to coexist with other species while making their life sustainable in urban areas. The whole education system should be re-investigated to verify whether we are lending ourselves towards sustainable development in building our habitats as coexistence may be the key to sustainability.


The article highlights the coexistence of species as most essential for the sustainability of human habitats. Identifying zones for the other species within human habitats and following appropriate methods for construction of a human dwelling and associated infrastructure will allow biodiversity in the cities. The article identifies the need for strong institutions and policies while stressing the necessity of education on sustainable living for city dwellers.


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Eng. K. K. K. Sylva
Senior Lecturer
Department of Engineering Management
Faculty of Engineering
University of Peradeniya

Eng. K. K. K. Sylva has earned her BSc. Eng., specializing in Civil Engineering from the University of Peradeniya, MEng from Asian Institute of Technology (AIT), MBA from PIM, University of Sri Jayawardenapura and MSc Sustainable Energy Engineering, University of Gävle, Sweden . She is currently serving as a Senior Lecturer at the Department of Engineering Management, Faculty of Engineering, University of Peradeniya.

Eng. (Dr.) C. S. Bandara
Senior Lecturer
Department of Civil Engineering
Faculty of Engineering
University of Peradeniya

Eng. (Dr.) C. S. Bandara has earned his BSc. Eng., specializing in Civil Engineering, MSc. Eng., specializing in Structural Engineering and PhD from the University of Peradeniya. He is currently serving as a Senior Lecturer at the Department of Civil Engineering, Faculty of Engineering, University of Peradeniya.

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