Green and Blue Infrastructure as Nature-Based Better Preparedness Solutions for Disaster Risk Reduction: Key Policy Aspects

Abstract

The impact of disasters has increased and intensified due to climate change, and its adverse impacts which have caused many losses and damage among communities worldwide. Studies have confirmed that the main causal factor is the adverse impact on the natural environment and its processes due to anthropogenic activities. Therefore, decision-makers are looking for new measures and approaches where ecosystems and nature-based solutions are recognised as successful and sustainable solutions. However, applications of ecosystems or nature-based solutions seem inadequate, particularly in planning disaster risk reduction at the local level. In this context, this paper aims to examine the policy perspective on green and blue infrastructure as a nature-based solution for better preparedness in disaster risk reduction. The study is based on a detailed literature review, combining a policy review supported by a review of academic papers. The results confirmed that international policies and frameworks recognised the importance of ecosystems or nature-based solutions as a best practice for disaster risk reduction where green and blue infrastructure can be successfully integrated. In conclusion, translating the ideas of nature-based solutions from international policies and frameworks into local and national level planning will strengthen community resilience through better preparedness.

1. Introduction

Humans have tried to understand and explain their surroundings or the environment and its processes through myths and beliefs in the past [1] and recently through the advancement of sciences. Knowledge gathered based on empirical studies has provided explanations for environmental processes that have encouraged the ideas of human capabilities of alteration [2,3], which may have laid the foundation for the viewpoint of environmental possibilism [4]. Based on this ideology, many people in the early 20th century believed they could change the environment using scientific knowledge, yet they did not think about the consequences. The counter theory of environmental determinism, which pointed out the fact that every natural phenomenon is based on natural laws [5], is almost rejected by ideas of environmental possibilism. Deterministic thought argued that humans would have to obey the laws of nature [6], whereas possibilistic thought highlights environmental control [7].

With an increasing population, the demand for natural resources rapidly increased [8], and humans were compelled towards environmental possibilism to fulfil their needs. Due to high demand, over-exploitation of natural resources such as land, crude oil, biomass, and water has led to rapid environmental degradation [9,10,11]. Since humans believed in their capability to control the environment, the changes were implemented all over the planet. Forest cover has depleted rapidly, and greenhouse gas emission has increased on a large scale [12]. Scientists issue warnings about climate change, and discussions are continuing among decision-makers of the world on mitigation strategies. World leaders agree on sustainable development principles, which seem to be a combination of both environmental possibilistic and deterministic views, where environmental stability for future survival was expected by all development projects [13].

Due to the changes made to the environment, the balance of nature was disrupted on both a micro and macro scale [14]. For example, emitted greenhouse gases have changed the radiation balance of the Earth’s atmosphere by increasing the retention time of the incoming solar radiation of the lower atmosphere [15,16]. This has increased the average temperature of the lower atmosphere, identified as global warming, which has a cascading impact on several other environmental systems. Since Earth’s climate is driven by incoming solar radiation [17], the retained heat has altered climatic conditions such as heating, depression building, hydraulic cycle, wind formation and even El Niño and La Niña, which creates devastative, disastrous events all over the planet [15].

To face the devastative impact of natural hazards, scientists and decision-makers have tried many technology-based applications for disaster mitigation and risk reduction. Sea walls, groynes, and breakwaters for coastal erosion prevention [18], flood controlling dam systems [19], and slope stabilisation using hard engineering structures [20] are some of the examples, among many others. However, many of these initiatives have started to fail recently due to the increasing intensities and frequencies of natural hazards. For example, Bangladesh’s flood-controlling dam systems, which were a successful structural engineering implementation for flood mitigation, started failing in many parts of the country due to extreme flood conditions [21]. Therefore, new environmental-based approaches were proposed by many scholars, and promising results have been obtained in many parts of the world.

Natural hazards have existed for a very long time, yet with human interference they have become disasters causing loss of human lives and the destruction of properties on a large scale. For example, anthropogenic activities have occupied most marginal lands such as steep slopes, flood plains and coasts where the disastrous events are most active. It is believed that restoring the balance of the natural processes up to a certain extent will have a significant impact on disaster risk reduction and mitigation [22]. Therefore, decision-makers are moving towards nature-based solutions [23] and ecosystems-based disaster risk reduction [24] in their efforts to make communities resilient. Under the applications of nature-based solutions and ecosystems-based disaster risk reduction, green and blue infrastructure initiatives are considered to be one of the successful implementations for built environment planning [25,26]. Furthermore, studies have shown that green and blue infrastructure initiatives have had promising results in climate change mitigation [27], managing flash floods [28], landslides, [29], and preventing coastal erosion [30], among many other applications.

Green infrastructure refers to multifunctional green spaces that can be adopted in urban and rural landscapes, and that improve the quality of life and environmental benefits for communities [31,32]. Green infrastructure facilitates ecosystem-based initiatives such as roof gardens, vertical gardens, open green spaces, public parks, etc. [33,34], that support climate change mitigation, disaster resilience, and community wellbeing [35]. Blue infrastructure facilitates water-associated ecosystems for the same purpose above [36]. This includes urban ponds, rain gardens, wetlands, canals, and other water-associated ecosystems. Under the nature- and ecosystems-based solutions for disaster risk reduction, green and blue infrastructure features are encouraged as an environmentally sustainable solutions for making communities resilient [37]. However, understanding of policies concerning green and blue infrastructure and their support among decision-makers and practitioners needs to improve. In addressing this scope, this paper aims to understand the policy support for green and blue infrastructure implementation towards disaster risk reduction for better preparedness among local and national communities.

Regarding disaster risk reduction, the measures of ecosystem-based disaster risk reduction (Eco-DRR) and ecosystem-based adaptation (EbA), green infrastructure and blue infrastructure fall under the umbrella term of nature-based solutions (NbS) [38]. When it comes to local DRR, these different terminologies may express similar meanings reflected by the umbrella term nature-based solutions. Vertical gardening, roof gardening, open green spaces, green belts, and urban wetlands are some of the most mentioned examples under the heading of green and blue infrastructure. However, the current practices of local DRR indicate that there is a limitation in existing measures focusing on nature-based solutions such as green and blue infrastructure [39]. The integration of ecosystem services and biodiversity into local level disaster risk reduction planning seems limited and needs more support from national and international level policies and institutions [15,40]. It seems there is limited knowledge on measures for integrating nature-based solutions into local planning, and on the existing policy support [41]. The research so far has shown that most of the measures under the nature-based solutions umbrella are locally inspired based on the environmental and societal contexts [2,42], yet dissemination and generalization of such knowledge needs more support [43].

Nature-based solutions provide the means for decision makers and practitioners to successfully manage the water, energy, and climate relationship while enhancing the resilience of urban communities [44], yet the implementation of nature-based solutions seems inadequate due to its complex nature [45,46]. Moreover, one of the main challenges of implementing nature-based solutions in a local context is the translation of these concepts into practice [36,38]. Another challenge is that there is a lack of studies on the assessment of practical adaptation and its reliability in local contexts [47]. Therefore, integrating nature-based solutions into local policies seems impractical without proper evidence. Moreover, many policies reflect the importance of nature-based solutions, yet there is a lack of support in implementation and adaptation to climate change [48]. This paper further explains that policies are clear about the large-scale nature-based solutions implementation, but the ability to bring them into local urban agendas seems lacking.

Considering regional approaches, the incorporation of nature-based solutions into the 2020 research agenda of the European Commission can be considered as one good example [49], yet the success of these approaches is dependent on whether the local public willingly accept these approaches into their planning [25]. The European Union recognises nature-based solutions as an opportunity not only to safeguard the natural environment, but also to improve the business prospects and the position of the EU in the international market. However, many developing nations around the world do not recognize nature-based solutions as much as the developed nations. The policies need to be strengthened to create awareness about nature-based solutions as well as to improve research and find better financing opportunities [50].

A large portion of the economic contribution in many developing nations is from agricultural sector production. Therefore, it is important to support nature-based solutions in agriculture in local policies, not only to benefit sustainable management of land, water, and biodiversity, but also to reduce the risk from natural hazards [51]. The combination of science, policy, and practice towards the effective implementation of nature-based solutions will contribute to achieving all dimensions of sustainability [2]. Therefore, understanding the policy support for green and blue infrastructure seems one of the relevant topics when it comes to achieving sustainability among local communities.

2. Materials and Methods

This paper is based on a detailed policy review which was supported by a desk review. Many national, regional, and local policies support green and blue infrastructure as a nature-based solution for disaster risk reduction. Decision makers from the disciplines of urban planning and disaster management are exploring different approaches to better integrate green and blue infrastructure measures for better preparedness highlighted by their national, regional, and local policies.

However, international or global policies act as essential documents and guidelines for developing national, regional, and local policies. If the international or global policies have successfully integrated green and blue infrastructure as a nature-based solution for better preparedness, there is a high probability that this may be reflected within all national, regional, and local policies. Therefore, apart from the academic research papers, the researcher has selected four global policies which focus on disaster risk reduction, sustainable development, and urban planning to see how they have incorporated green and blue infrastructure for better preparedness for disaster risk reduction. The selected policies are:

• Sendai Framework for Disaster Risk Reduction [52]
• 2030 Agenda for Sustainable Development [53]
• Paris Agreement [54]
• New Urban Agenda [55]

There was a key word search carried out using the same keyword in the search string to explore how these policies have identified the keyword under the scope of sustainable development. Based on a thematic analysis, key discussion areas were identified.

The broader research consists of two segments of review, as in policy review and systematic review. The same keywords which were used in the systematic review were used as the keywords of the policy review. Search string of the systematic review:

(“Green Infrastructure” OR “Blue Infrastructure”) AND (“Ecosystem” OR “Environment”) AND (“Disaster Risk Reduction” OR “Disaster Management”)

However, this paper will illustrate only the findings of the policy review. A desk review with a combination of academic research papers and institutional reports has supported the policy review in supporting the key areas of discussion.

3. Results

Global policies and frameworks currently in place related to disaster risk reduction and urban planning are the Sendai Framework for Disaster Risk Reduction (SFDRR), the 2030 Agenda for Sustainable Development, the Paris Agreement, and the New Urban Agenda. These policies and frameworks are key contributors to the decision-making process in all development activities where disaster risk reduction is one of the key concern areas. Moreover, each policy or framework has incorporated nature-based solutions as a sustainable mechanism for better preparedness where green and blue infrastructure can be successfully integrated.

3.1. The Sendai Framework for Disaster Risk Reduction (SFDRR)

The Sendai framework for Disaster Risk Reduction was adopted in 2015 by the United Nations at the world conference on disaster risk reduction held in Sendai, Japan. This is the successor agreement to the Hyogo Framework for Action, and functions closely with the 2030 Agenda for Sustainable Development. The SFDRR for action functions is based on a concise, focused, forward-looking, and action-oriented platform, and gives more provision to the experience gained through the regional and national strategies/institutions and plans for disaster risk reduction and their recommendations [56]. It recognises the incorporation of local knowledge and community participation where nature-based solutions can be adopted into disaster risk reduction with the support of local communities. However, in SFDRR, the terms of green and blue infrastructure are not directly highlighted, yet more provision is given for adopting green and blue infrastructure practices through other actions. Moreover, there are several highlights about ecosystems where the framework recognises ecosystems as a significantly important component in disaster risk reduction.

“It is urgent and critical to anticipate, plan for and reduce disaster risk in order to more effectively protect persons, communities and countries, their livelihoods, health, cultural heritage, socioeconomic assets and ecosystems, and thus strengthen their resilience”.

—SFDRR, p. 10—

However, before the Sendai Framework for Disaster Risk Reduction, the Hyogo Framework for Action identified ecosystems as a significant contributor to DRR [52]. The Hyogo Framework for Action recognised that ecosystems need to be protected for better preparedness. Studies have proven the importance of ecosystems in disaster risk reduction [57,58,59]. Well-preserved ecosystems can act as a protective barrier for the local communities. For example, coastal mangroves and vegetation on steep slopes will protect the communities from coastal erosion, tsunami waves and landslides [36,60,61]. However, the SFDRR recognised the direct importance of ecosystems in disaster preparedness.

“More dedicated action needs to be focused on tackling underlying disaster risk drivers, such as the consequences of poverty and inequality, climate change and variability, …, declining ecosystems, pandemics, and epidemics”.

—SFDRR, p. 10—

The SFDRR identifies declining ecosystems as a disaster risk drive which can enhance the impact of natural hazards. Declining ecosystems will significantly change the local environment, which enhances the risk from natural hazards. For example, deterioration of the coastal mangrove ecosystem can lead to coastal erosion [62]. As a mechanism for tackling the underlying risk from natural hazards, ecosystems management [57], environmental conservation [59,63], and nature-based solutions [64] are introduced as successful measures where green and blue infrastructure can be integrated.

Compared to the Hyogo Framework for Action, the SFDRR has given more provision towards ecosystem resilience where green and blue infrastructure measures can be directly acknowledged. As mentioned below, one of the primary outcomes of the SFDRR is to reflect the importance of environmental assets and reduce environmental losses.

“Prevent new and reduce existing disaster risk through the implementation of integrated and inclusive economic, structural, legal, social, health, cultural, educational, environmental, technological, political and institutional measures that prevent and reduce hazard exposure and vulnerability to disaster, increase preparedness for response and recovery, and thus strengthen resilience”.

—SFDRR, p. 12—

The SFDRR, in its goal of achieving the expected outcome, has identified, integrated, and included environmental measures to prevent new risks and reduce existing disaster risks. Under the integrated and inclusive measures, it gives the necessary provision for incorporating ecosystem resilience into development planning. Moreover, it will provide a window for incorporating green and blue infrastructure measures into sustainable urban planning.

The SFDRR names seven global targets under the aim of achieving the expected outcome by 2030. Under these targets, ecosystem resilience and blue and green infrastructure measures can be incorporated within Target E (substantially increase the number of countries with national and local disaster risk reduction strategies by 2020), where local disaster risk reduction strategies can focus on nature-based solutions.

The behaviour of the disasters mainly depends on the local environmental conditions. Strategies of disaster risk reduction and mitigation must understand the behaviour of the disaster by looking at the local environmental parameters, which are reflected by the SFDRR as mentioned below.

“While the drivers of disaster risk may be local, national, regional or global in scope, disaster risks have local and specific characteristics that must be understood for the determination of measures to reduce disaster risk”.

—SFDRR, p. 13—

If the mitigation strategies are based on environmental principles, they are more adaptive to local environmental conditions. Therefore, the understanding of local and specific characteristics of disasters may have more sustainable outcomes when it comes to disaster risk reduction. Furthermore, as mentioned earlier, the local level approaches have more provision to integrate nature-based solutions which are specific to that particular context. Moreover, implementing nature-based solutions based on Target E will also successfully influence the Sendai targets of A, B, C and D (Figure 1).

“Managing the risk of disasters is aimed at protecting persons and their property, health, livelihoods and productive assets, as well as cultural and environmental assets, while promoting and protecting all human rights, including the right to development”.

“The development, strengthening and implementation of relevant policies, plans, practices and mechanisms need to aim at coherence, as appropriate, across sustainable development and growth, food security, health and safety, climate change and variability, environmental management and disaster risk reduction agendas”.

—SFDRR, p. 13—

The above section, adopted from the guiding principles of the SFDRR, has also highlighted the protection of environmental assets as a mechanism for managing disaster risk. This is a win–win situation for humans and the environment where well preserved environments and ecosystems support disaster risk reduction and mitigation by the preservation of their local environmental processes. Well-preserved ecosystems will act as a natural barrier for many natural hazards [65]. The SFDRR also recognises environmental management as a strategy for development where sustainable development practices can incorporate ecosystem resilience.

The SFDRR has four priority areas for better implementation of the targets. They are:

• Priority 1: Understanding disaster risk.
• Priority 2: Strengthening disaster risk governance to manage disaster risk.
• Priority 3: Investing in disaster risk reduction for resilience.
• Priority 4: Enhancing disaster preparedness for effective response and to “Build Back Better” in recovery, rehabilitation, and reconstruction.

Each priority area can be directly linked with ecosystems or the nature-based DRR. When understanding the disaster risk, understanding of local environmental conditions is essential [66]. Emphasis on a periodical assessment of the disaster risk based on the ecosystems will support a better understanding of the behaviour of disasters within local environments. The behaviour of the disasters depends on the ecosystem characteristics, where the same disastrous event has a different impact on a different ecosystem [24]. Therefore, environmental parameters under a given ecosystem should be considered when assessing the risk.

Section C on page 15 of the SFDRR emphasises location-based risk information to optimise the process of decision making when it comes to planning. The SFDRR highlights the compilation of risk maps mainly based on geospatial information technology used in understanding the risk. From the ecosystem perspective, it is possible to incorporate the ecosystems and the ecosystem functions into risk maps. Considering the ecosystem as the control factor, it can simulate different scenarios of how the ecosystem will protect local communities. Restored and resilient ecosystems can reduce the risk, and degraded ecosystems can increase the risk, causing more devastative impacts on communities [53]. Therefore, ecosystems can be used as a parameter for risk mapping to understand the risk accurately. As highlighted by the SFDRR, keeping records of the impact on ecosystems may support understanding of the risk more accurately, as well as providing an opportunity to forecast future risk scenarios.

The SFDRR has also given provision for knowledge sharing, use of scientific knowledge, strengthening capacities and many more areas easily adopted into the Eco-DRR framework. Under Priority 2, which is strengthening disaster risk governance to manage disaster risks, it has also highlighted environmental resilience as a strategy for the prevention of creating risk, and reducing existing risk. It is the responsibility of each nation to develop strategies to make the ecosystems more resilient as a mechanism of DRR. The SFDRR can be used as an international platform to develop such strategies and implement them in local communities. It also highlights the requirement of mechanisms to ensure the environmental standards of such implementations. The country’s environmental authorities can act as a leading institute for authorisation and investigation of the standard environmental methods adopted locally.

“To promote trans boundary cooperation to enable policy and planning for the implementation of ecosystem-based approaches with regard to shared resources, such as within river basins and along coastlines, to build resilience and reduce disaster risk, including epidemic and displacement risk”.

—SFDRR, p. 18—

Further, under Priority 2, the SFDRR has identified the significance of ecosystem-based approaches to build resilience and reduce disaster risk. Though they highlight more on the transboundary corporation side, ecosystems-based approaches can be used as more local level strategies for disaster risk reduction [67]. Even small ecosystems can have a significant contribution to disaster risk reduction. As an example, a small coastal mangrove ecosystem can protect a few houses from getting eroded due to coastal surges. Furthermore, this highlights the importance of policy and planning for implementing ecosystem-based approaches. No matter how well the research has highlighted the significance of ecosystem-based approaches, legislative support is essential when it comes to implementation [31,68]. Without solid legal support, institutes, individuals and even decision makers are not obliged to use the ecosystems-based measures for disaster risk reduction in their development projects.

The SFDRR also discussed environmental impact assessment (EIA) as a measure of disaster risk prevention and reduction. This is important for sustainable development, where development plays a key role in environmental degradation [69,70,71]. Therefore, before implementing any development activity, adequate EIA should be encouraged, mainly to see how that project will have an impact on ecosystem degradation. Moreover, as mentioned above, it is essential to have strong legal support to make sure that all development activities follow the recommendations given by the EIA reports to preserve and conserve local ecosystems.

“To strengthen the sustainable use and management of ecosystems and implement integrated environmental and natural resource management approaches that incorporate disaster risk reduction”.

—SFDRR, p. 19—

Managing ecosystems is one of the important roles of DRR, where future generations will also benefit from the ecosystem services [21,72]. Therefore, nature-based solutions and ecosystems-based approaches are encouraged by the SFDRR to preserve existing ecosystems where green and blue infrastructure measures can contribute successfully to achieving the expected outcomes.

The impact of disasters can disrupt the development process by pushing it nearly three years back [73,74,75]. More frequent disasters mean more disruptions to the process of sustainable development. However, the SFDRR has emphasised the need to strengthen DRR towards a more sustainable development process [76,77]. Scholars have pointed out that anthropogenic activities have increased disaster risk simply by contributing to the degradation of environmental functions [78,79,80,81]. Therefore, new approaches have emerged as a solution where global policies such as the SFDRR have adopted and facilitated the ideas of ecosystem resilience in disaster risk reduction.

The provisions given under the quote mentioned above support blue and green infrastructure initiatives, especially in urban planning. The increasing recognition for Eco-DRR has influenced the incorporation of ecosystems in the SFDRR in its Priorities for Action, in the Guiding Principles, Goals, and Expected Outcomes [48,82]. Although the SFDRR has not directly included ecosystems in any of the global targets, it has strengthened the sustainable use and management of ecosystems, and integrated environmental and natural resource management approaches which directly coincide with blue and green infrastructure [44,82]. The paper further highlights that green infrastructure approaches can be used to monitor direct economic loss under the indicators C5 and D4. It also conceptualised the green infrastructure for the SFDRR as follows (Figure 2). It has also identified two components in protective and critical green infrastructure that support disaster prevention and impact mitigation.

Under Target E of the SFDRR, DRR has provisions to incorporate green and blue infrastructure measures under the ecosystem-based approaches. Within the recent applications of DRR, there has been a transformation towards green and blue infrastructure among adaptation and mitigation strategies [83,84,85]. It is believed that grey infrastructure tries to control, remove, and manipulate existing ecosystems, and it disrupts the natural processes [86]. Therefore, under the SFDRR, green and blue infrastructure implementation is more encouraged, whereas Target E provides more provision for the adaptation of such measures.

3.2. The 2030 Agenda for Sustainable Development

The 2030 Agenda for Sustainable Development or Sustainable Development Goals (SDG) was adopted by the United Nations General Assembly on 25 September 2015 to eradicate world poverty through sustainable development practices. The countries adopting the 2030 Agenda for Sustainable Development have set up their development goals according to the agenda targets.

The SDG have identified best practices and suggestions through vast areas of fields recognised under the 17 global targets. It has also recognised disasters as an obstacle to the development process, and that disaster risk reduction should be a compulsory component in all development activities. The SDG have recognised the three dimensions of sustainable development as social, economic and environmental. Under the environmental dimension, nature-based solutions and ecosystems-based practices can be successfully integrated into disaster risk reduction and mitigation.

The SDG are based on the outcomes of all major United Nations conferences and summits related to development activities. These include the outcomes from the Rio Declaration on Environment and Development, the World Summit on Sustainable Development, the World Summit for Social Development, the Programme of Action of the International Conference on Population and Development, the Beijing Platform for Action, and the United Nations Conference on Sustainable Development, along with many others. The outcomes from the Rio Declaration especially have laid a strong foundation on environmental sustainability [87], where ecosystem resilience can be easily accommodated into development planning.

“Natural resource depletion and adverse impacts of environmental degradation, including desertification, drought, land degradation, freshwater scarcity and loss of biodiversity, add to and exacerbate the list of challenges which humanity faces. Climate change is one of the greatest challenges of our time and its adverse impacts undermine the ability of all countries to achieve sustainable development. Increases in global temperature, sea level rise, ocean acidification and other climate change impacts are seriously affecting coastal areas and low-lying coastal countries, including many least developed countries and Small Island developing States”.

—2030 Agenda for Sustainable Development, p. 05—

Under the 2030 Agenda for Sustainable Development vision, primary concern is given to safe drinking water and sufficient, safe, affordable, and nutritious food. Well-preserved ecosystems can easily provide safe drinking water by reducing water scarcity and increasing groundwater retention capacities [87,88,89]. They can also ensures food security by providing sufficient food and herbs for the local communities, among other benefits [90,91,92]. These are the known benefits of ecosystem services. Furthermore, studies have shown that preserved and restored ecosystem functions will act as a natural mechanism of disaster risk reduction [93,94,95]. They also contribute towards mitigating climate change impacts [77].

“A world in which consumption and production patterns and use of all natural resources—from air to land, from rivers, lakes and aquifers to oceans and seas—are sustainable”.

—2030 Agenda for Sustainable Development, p. 04—

The SDG have given more consideration to environmental sustainability to sustain human lives on the planet [96]. It is accepted that ecosystem resilience is one of the best practices for environmental sustainability. Blue and green infrastructure measures incorporated into land use planning will support the ecosystem resilience, which contributes towards building self-sustaining communities and resilient communities when faced with disasters.

The SDG have clearly identified environmental degradation as a disrupting factor of sustainable development and as a causal factor for climate change, which again disrupts the development process by increasing the frequency and magnitude of natural hazards. Therefore, restoring the degraded environments by adopting ecosystem resilience seems to be one of the solutions which is emphasised by many scholars for productive disaster risk reduction [36,96,97]. This environmental approach supports the green and blue infrastructure applications for sustainable development, supporting the restoration and conservation of the natural environment.

“We acknowledge that the United Nations Framework Convention on Climate Change is the primary international, intergovernmental forum for negotiating the global response to climate change. We are determined to address decisively the threat posed by climate change and environmental degradation”.

—2030 Agenda for Sustainable Development, p. 08—

Sustainable development goals have recognised that climate change and environmental degradation are clearly linked. The quote above emphasises addressing the threats posed by climate change and environmental degradation, which are interconnected. The 2030 Agenda for Sustainable Development therefore emphasises climate change mitigation based on the preservation of the local environment under the development activities [98,99]. The SDG’s primary aim in the United Nations Framework Convention on Climate Change (UNFCC) is to prevent “dangerous” human interference with the climate system to prevent further changes. It has also considered the steps to mitigate climate change through ecosystem-based solutions, such as increasing carbon sequestration by increasing the number of ecosystems [27,100,101]. Therefore, there are more opportunities to incorporate blue and green infrastructure measures in urban planning toward sustainable development.

“We recognise that social and economic development depends on the sustainable management of our planet’s natural resources. We are therefore determined to conserve and sustainably use oceans and seas, freshwater resources, as well as forests, mountains and dry lands and to protect biodiversity, ecosystems and wildlife”.

—2030 Agenda for Sustainable Development, p. 09—

Green and blue infrastructure measures can contribute to the sustainable management of natural resources through ecosystem resilience [89,102], which supports the sustainable management of plants, as mentioned above. Resilience ecosystems also act as a mechanism for reducing the disaster risk to local communities [57]. The 2030 Agenda for Sustainable Development has identified the importance of the sustainable management of natural resources, where ecosystem-based solutions can be easily incorporated [84]. For example, the preservation of mangrove ecosystems can provide resources such as fish, herbs, fuel wood, and fruits, among other ecosystem services, to their local communities. However, management of these resources without over-exploitation must be guided by the involvement of experts.

The 2030 Agenda has also reflected upon sustainable urban planning where environmentally sound management activities are more encouraged [102]. Blue and green infrastructure measures are more relevant in urban planning, which can incorporate spatial planning to adopt a blue and green solution productively [50,103]. Practices such as green roofs, urban forestry, and water conservation have already contributed to planning activities and supports to increase the adaptive capacity through planning, preparing, or reducing climate-related vulnerabilities [41]. The use of green and blue infrastructure for the sustainable management of urban flood risk has already been recognised [104]. Under the current practices, cities seem to be expanding and improving the incorporation of green infrastructure measures under spatial planning [105]. Therefore, green and blue infrastructure measures are considered important under the urban planning concepts, and the 2030 Agenda for Sustainable Development has provided a strong international platform for all decision-makers.

“We recognise that there are different approaches, visions, models and tools available to each country, in accordance with its national circumstances and priorities, to achieve sustainable development; and we reaffirm that planet Earth and its ecosystems are our common home and that “Mother Earth” is a common expression in a number of countries and regions”.

—2030 Agenda for Sustainable Development, p. 13—

As mentioned above, the 2030 Agenda for Sustainable Development emphasises the protection of planet Earth and its ecosystems under sustainable development activities. Within that scope, there is more provision to adopt green and blue infrastructure applications in urban and land use planning under sustainable development.

All 17 goals of the 2030 Agenda for Sustainable Development have direct and indirect links to ecosystems or nature-based solutions. Some goals that depicts direct links are Goal 09: build resilient infrastructure, promote inclusive and sustainable industrialisation and foster innovation; Goal 11: make cities and human settlements inclusive, safe, resilient and sustainable; Goal 13: take urgent action to combat climate change and its impacts, and Goal 15: protect, restore and promote the sustainable use of terrestrial ecosystems, sustainably manage forests, combat desertification, and halt and reverse land degradation and halt biodiversity loss, which are directly linked with ecosystems or the nature-based solutions.

3.3. The Paris Agreement under the United Nations Framework Convention on Climate Change

The Paris Agreement was adopted by the United Nations Framework Convention on Climate Change (UNFCCC) in 2016 with 189 partners. The primary aim of the Paris Agreement is to reduce greenhouse gas emissions for climate change adaptation and mitigation. Therefore, it directly adheres to sustainable ecosystem management. Under the Paris Agreement, there is a high possibility of adopting green and blue infrastructure measures as ecosystems or nature-based solutions into development policies.

The Paris Agreement focuses on maintaining the global temperature levels by reducing the emission of greenhouse gases, where ecosystem-based solutions are highly encouraged. It is believed that environmental degradation incorporated with rapid industrialisation has led to this situation, by disrupting the natural balance of the solar radiation budget [106,107,108]. Therefore, conserving and restoring ecosystems while reducing the emission of greenhouse gases from development activities can mitigate the climate change effects in due time.

“Noting the importance of ensuring the integrity of all ecosystems, including oceans, and the protection of biodiversity, recognised by some cultures as Mother Earth, and noting the importance for some of the concept of “climate justice”, when taking action to address climate change”.

—Paris Agreement, p. 02—

The Paris Agreement has recognised the importance of ensuring the integrity of all ecosystems where sustainable practices of development activities are welcome. Mother Nature can survive whether it has humans on it or not. It is the responsibility of humans to acknowledge the natural processes and order when engaged in development activities. Many scientists believe climate change is a result of disrupting the natural process of nature [51,109,110]. Because of that, decision-makers are moving towards ecosystems or nature-based solutions. Therefore, the possibility of adopting blue and green infrastructure measures under the ecosystem- or the nature-based approach is high.

The Paris Agreement highlights climate-resilient development and low greenhouse gas emissions as a mechanism of disaster mitigation. Low greenhouse gas emission is significant in climate change mitigation and disaster risk reduction to make communities resilient [111]. Increasing carbon sequestration combined with low greenhouse gas emissions supports climate change mitigation with more promising results [112]. Any integrated green infrastructural measures can increase carbon sequestration, especially in urban areas.

Article 04 of the Paris Agreement highlights the importance of greenhouse gas sinks. It is essential because the emission of greenhouse gases is inevitable in development processes, especially in developing countries. As a counter measure, greenhouse gas sinks have been identified as a measure of restoring the balance between emission and sequestration [32]. Therefore, restored ecosystems play a vital role by acting as an agent of long-term storage of carbon dioxide or other forms of carbon to either mitigate or defer global warming and avoid the dangerous impact of climate change [113,114,115]. Many private sector companies are contributing to this effort through tree plantation campaigns to reduce their carbon footprint on the planet.

“Parties are encouraged to take action to implement and support, including through results-based payments, the existing framework as set out in related guidance and decisions already agreed under the Convention for: policy approaches and positive incentives for activities relating to reducing emissions from deforestation and forest degradation, and the role of conservation, sustainable management of forests and enhancement of forest carbon stocks in developing countries; and alternative policy approaches, such as joint mitigation and adaptation approaches for the integral and sustainable management of forests, while reaffirming the importance of incentivising, as appropriate, non-carbon benefits associated with such approaches”.

—Paris Agreement, Article 05, p. 06—

Forests are considered highly diverse ecosystems, and preserving existing forests and increasing the number of forest ecosystems significantly impacts carbon sequestration, reducing climate change impacts [116,117]. Global forest cover has degraded rapidly because of anthropogenic activities, and the regeneration of forest cover is significantly low compared to deforestation [118,119]. Therefore, current development activities have reduced carbon absorption from the atmosphere by removing the forest cover, while increasing the emission of carbon by increasing the industries [106]. Scientists have identified that balance must be restored to mitigate the extreme climate effects, and ecosystem resilience appears as one of the best solutions. Therefore, the incorporation of greenery into spatial planning will be one of the successful measures to implement [120,121].

The Paris Agreement emphasises increasing the adaptive capacities of nations to climate change and recognises protecting ecosystems as a measure of adaptation. As highlighted by the SFDRR and the 2030 Agenda for Sustainable Development, well-preserved ecosystems can act as a barrier to natural disasters. Implementing green and blue infrastructure measures can restore lost or degraded ecosystems to a certain extent [97]. The Paris Agreement also recognises the importance of local knowledge and local communities on ecosystem resilience activities. It can also increase their accountability in preserving their livelihood activities while supporting the ecosystem’s resilience.

The Paris Agreement stresses the need to assess climate change impacts and vulnerability. Each development project should assess its impact on disaster risk, climate change or how it affects natural environmental processes, which has a cascading impact. Environmental Impact Assessment (EIA) is one such initiative which is successful in many countries [25,97]. Through the assessment process, vulnerable communities and vulnerable ecosystems can be easily identified and ecosystem-based approaches such as green and blue infrastructure measures can be introduced as a resilience strategy [122,123,124].

“Building the resilience of socioeconomic and ecological systems, including through economic diversification and sustainable management of natural resources”.

—Paris Agreement, article 07, p. 11—

Under Article 07 of the agreement, the resilience of the ecological systems towards the sustainable management of natural resources is highlighted as an essential factor in the development process. Ecosystem resilience can be used in urban and rural land use planning [18]. In urban contexts it is essential to sustainably manage the space, since urbanised ecosystem degradation is significantly high. Green spaces are declining rapidly, and more green and blue infrastructure measures are being implemented to restore the balance. However, more ecosystems tend to degrade in the rural context due to agriculture and pasture [125,126]. Sensitive ecosystems such as woodlands, wetlands, and forests are more vulnerable in rural areas. Therefore, activities under ecosystem resilience are equally applicable in any part of the region where ecosystems are under threat.

Another highlighted area of the Paris Agreement is minimising the loss and damage associated with the adverse effects of climate change. These adverse effects are most visible as natural hazards [127,128,129]. Resilient and managed ecosystems can absorb the impact of natural hazards and reduce the impact on communities [38,130]. Therefore, more ecosystems mean more resilience from natural hazards. This will directly minimise the loss and damage from adverse effects of climate change. Under Article 08 paragraph 01, which emphasises reducing the risk of loss and damage, incorporating green and blue infrastructure measures for ecosystem resilience can be easily adopted in development planning.

3.4. New Urban Agenda (Quito Declaration on Sustainable Cities and Human Settlements for All)

The New Urban Agenda was adopted at the United Nations Conference on Housing and Sustainable Urban Development (Habitat III) in Quito, Ecuador, on 20 October 2016 to utilise urbanisation as a tool of sustainable development. It also adheres to sustainable development goals and provides the underpinning for actions to address climate change [19]. The New Urban Agenda is based on sustainable urban planning through cultural and social well-being while protecting the natural environment and ecosystems [53,104]. The world’s urban population is expected to nearly double by 2050, and more challenges will be posed by urban growth. However, the New Urban Agenda supports sustainable urban development by incorporating environmental sustainability into urban planning [131,132]. Along with inclusive economic growth and social and cultural development, the New Urban Agenda adheres to environmental protection and nature-based solutions for urban planning.

“By readdressing the way cities and human settlements are planned, designed, financed, developed, governed and managed, the New Urban Agenda will help to end poverty and hunger in all its forms and dimensions; reduce inequalities; promote sustained, inclusive and sustainable economic growth; achieve gender equality and the empowerment of all women and girls in order to fully harness their vital contribution to sustainable development; improve human health and wellbeing; foster resilience; and protect the environment”.

—New Urban Agenda, p. 03—

The New Urban Agenda addresses many priority areas where resilience and environmental protection are important. It is highlighted that under urbanisation, environmental degradation is significantly high, and many green and blue spaces are disappearing at an alarming rate [133,134]. Therefore, green and blue infrastructure measures are introduced mainly for urban areas to sustain the local environment through ecosystem resilience [135,136]. They will also support making urban areas more resilient to natural hazards. For example, urban wetlands, marshlands, and ponds under the blue infrastructure are contributing towards urban flood control.

The New Urban Agenda considered the recommendations and outcomes of other international policies and frameworks such as the SFDRR, the 2030 Agenda for Sustainable Development, the Paris Agreement, and the Addis Ababa Action Agenda. In addition, it has also taken into account the Rio Declaration on Environment and Development, among several other environmental treaties [26]. Therefore, the adaptation of ecosystem-based planning under the New Urban Agenda can be made without any legislative obstacles.

International policies and frameworks have provided a solid basis for environmental sustainability, ecosystem resilience and Eco-DRR perspectives in the New Urban Agenda. Therefore, green and blue infrastructure measures can be acknowledged as a sustainable practice in urban planning. Examples include green patches, green roofs, which reduce urban heat, and urban wetlands and ponds, which act as rainwater retention areas. The New Urban Agenda contributes to achieving the Sustainable Development Goals and Targets by implementation and localisation, including Goal 11 of making cities and human settlements inclusive, safe, resilient, and sustainable.

“Are participatory, promote civic engagement, engender a sense of belonging and ownership among all their inhabitants, prioritise safe, inclusive, accessible, green and quality public spaces that are friendly for families, enhance social and intergenerational interactions, cultural expressions and political participation, as appropriate, and foster social cohesion, inclusion and safety in peaceful and pluralistic societies, where the needs of all inhabitants are met, recognising the specific needs of those in vulnerable situations”.

—New Urban Agenda, p. 05—

The importance of green and public spaces in an urban context has been highlighted as vital since they contribute to human wellbeing. These spaces are not only useful to reduce stress and boost mental and physical health but also to act as protective measures against climate change and disasters such as heat, flash floods, etc. [45,137,138]. However, when managing these public green spaces, it is important to understand the ecological functions and services they provide. It is always better to understand the environmental systems and processes in advance. This will provide insight into better integrating green public spaces as a disaster risk reduction strategy.

The new urban agenda has stressed the territorial functions across administrative boundaries, which function in both human and ecological systems. Each territory has its unique functionality to keep up the balance of nature, whereas urban development activities have overlooked this aspect under the development perspectives [139]. These disturbed environmental functions may result adversely in the same urban area recognised as disasters. For example, the primary function of the wetlands and marshes is to absorb excess water from rain or river discharge [140]. However, the current urban practices filled these lands for industrial and settlement purposes [141]. It disrupts the natural process of infiltration and causes floods and flash floods in urban areas.

“Adopt and implement disaster risk reduction and management, reduce vulnerability, build resilience and responsiveness to natural and human-made hazards and foster mitigation of and adaptation to climate change”.

“Protect, conserve, restore and promote their ecosystems, water, natural habitats and biodiversity, minimise their environmental impact and change to sustainable consumption and production patterns”.

—New Urban Agenda, p. 07—

The New Urban Agenda has clearly focused on DRR and climate change mitigation in urban landscapes to build resilient cities. Recent studies have shown that ecosystem-based approaches are more appropriate for urban areas to increase resilience [142,143,144,145]. The application of green and blue infrastructure will support the urbanisation processes without degrading the local ecosystems and ecosystem functions. As mentioned by the New Urban Agenda, protecting, conserving, restoring, and promoting the ecosystems are essential under sustainable urban planning.

Within the context of principles and commitments, the New Urban Agenda has again pointed out the importance of environmental sustainability in urban planning. Research has shown that hard structural engineering measures have limitations when making cities resilient [28,98,146]. Therefore, in combination with ecological measures, there is a higher success rate in making cities resilient against disasters. Therefore, protecting ecosystems and biodiversity, including adopting healthy lifestyles in harmony with nature, is highlighted as necessary in the New Urban Agenda.

The New Urban Agenda also stressed the environment-responsive solutions within the land and property rights continuum. The rights to the land owned by different stakeholders of the development sector where development practices are also varied accordingly. However, environmental-responsive solutions in land management can support the ecosystem resilience activities which contribute to the sustainability of the entire urban community. Therefore, policies and frameworks, including national and regional policies, should have strong legislative support to adopt green and blue infrastructure measures in urban planning which adhere to the environment-responsiveness.

“We recognise that urban form, infrastructure and building design are among the greatest drivers of cost and resource efficiencies, through the benefits of economy of scale and agglomeration and by fostering energy efficiency, renewable energy, resilience, productivity, environmental protection and sustainable growth in the urban economy”.

—New Urban Agenda, p. 14—

As mentioned above, within the context of urban infrastructure measures, energy efficiency, renewable energy, resilience, productivity, and environmental protection are recognised as essential factors to adopt in urban development. Green and blue infrastructure facilitates resilience, productivity, environmental protection, and sometimes energy efficiency [37]. Therefore, integration of sustainable management and use of natural resources and land is highlighted as necessary by the New Urban Agenda.

The New Urban Agenda further emphasises reducing the financial, environmental, and public health costs of inefficient mobility, congestion, air pollution, urban heat island effects, and noise. Adopting ecosystem resilience through green and blue infrastructure measures will productively address air pollution and urban heat issues. Green infrastructure practices such as trees, green roofs and green walls are widely used in the United States and Europe to mitigate air pollution. It was also proved that incorporating more greenery can reduce the heat significantly in an urban area [147,148]. Therefore, more provisions must be given to green and blue infrastructure measures under the New Urban Agenda for urban development. This will also preserve the clean environmental conditions and good air quality, as the New Urban Agenda again mentions.

“We recognise that cities and human settlements face unprecedented threats from unsustainable consumption and production patterns, loss of biodiversity, pressure on ecosystems, pollution, natural and human-made disasters, and climate change and its related risks, undermining the efforts to end poverty in all its forms and dimensions and to achieve sustainable development”.

—New Urban Agenda, p. 18—

As mentioned above, the New Urban Agenda has recognised unsustainable consumption and production patterns, loss of biodiversity, pressure on ecosystems, pollution, natural and human-made disasters, and climate change and its related risks as threats to urban resilience. To mitigate these threats, implementing ecosystem-based adaptation measures seems to be one of the best potential solutions [149,150]. Well-managed ecosystems in an urban setting have the ability to sustain cities by increasing their resilience. It also reduces the carbon footprint on the planet with the application of sustainable energy consumption and resource management.

“We commit ourselves to facilitating the sustainable management of natural resources in cities and human settlements in a manner that protects and improves the urban ecosystem and environmental services, reduces greenhouse gas emissions and air pollution and promotes disaster risk reduction and management, by supporting the development of disaster risk reduction strategies and periodical assessments of disaster risk caused by natural and human-made hazards, including standards for risk levels, while fostering sustainable economic development and protecting the well-being and quality of life of all persons through environmentally sound urban and territorial planning, infrastructure and basic services”.

—New Urban Agenda, p. 18—

The New Urban Agenda has further recognised the importance of sustainable management of natural resources, urban ecosystems, and environmental services. More significant threats for the urban cities in the current world are the impact of disasters and adverse climate conditions [142,151]. The reasons for this adverse impact are the changes made to the environment or the environmental degradation. Authorities are adopting solutions to make cities resilient through the ecosystem-based approach, incorporating more green and blue infrastructure measures. As has been highlighted earlier, ecosystem resilience can solve many of these issues in urban contexts [14,125]. Therefore, incorporating the green and blue infrastructure measures to sustain urban ecosystem functions can be acknowledged under the New Urban Agenda for productive urban development.

Regarding the urbanisation process, the New Urban Agenda has considered urban deltas, coastal areas and other environmentally sensitive areas for conservation and preservation. Urban deltas play a vital role in flood mitigation and the prevention of saltwater intrusion to the inlands [152]. They also provide other ecosystem services such as habitat restoration, aquaculture, and scenic value to the urban area [153]. Many urban agglomerations are in the coastal zones where the impacts of natural hazards are high. Well-managed coastal ecosystems, including coastal mangroves, increase the resilience capacity of these cities [154]. The 2004 Indian Ocean tsunami has proven that coastal ecosystems are highly beneficial in absorbing the impact of the tsunami wave up to a considerable extent. Therefore, preserving the ecological functions mentioned by the New Urban Agenda seems important in sustainable urban planning activities.

“We commit ourselves to preserving and promoting the ecological and social function of land, including coastal areas that support cities and human settlements, and to fostering ecosystem-based solutions to ensure sustainable consumption and production patterns, so that the ecosystem’s regenerative capacity is not exceeded”.

—New Urban Agenda, p. 19—

To preserve the land’s ecological functions, the ecosystem resilience is essential in urban planning. All ecosystems’ functions contribute toward the earth system’s interrelated processes [55,120]. They can be hydrological, coastal, geophysical, and even climatological. Many of these functions are disrupted by the urbanisation process under the actions of development [133,155]. To overcome this issue, sustainable urban planning should have an ecosystem-based approach, to make cities resilient by sustaining the local ecosystem functions. Therefore, the New Urban Agenda is focused on facilitating ecosystem conservation, regeneration, restoration, and resilience in the face of new and emerging challenges.

The New Urban Agenda highlights the integrated water resources planning and management in territorial urban planning as another important aspect of development. Water is a resourceful factor if well managed, but it can create devastative impacts, mainly in urban regions. Many low-land urban cities are in the flood plains where flash floods and floods are witnessed [156]. Urban planners should understand the ecosystem functionality of the lowlands acting as the natural infiltration areas of excess water from the entire catchment [157]. Proper urban planning should recognise this function and plan the urban areas without disrupting the natural process. This is one of the main reasons to integrate urban wetlands and ponds as a part of recreation activities in the urban centres [158]. This will collect the surface runoff and retain it for longer until it gets absorbed. These measures of blue infrastructure can be incorporated as a sustainable measure of urban planning for disaster risk reduction.

“We commit ourselves to promoting international, national, subnational and local climate action, including climate change adaptation and mitigation, and to supporting the efforts of cities and human settlements, their inhabitants and all local stakeholders as important implementers”.

—New Urban Agenda, p. 22—

Ecosystem resilience has been identified as a sustainable measure against climate change mitigation [159,160]. It is pointed out that climate change results from ecosystem degradation, and restoring these ecosystems may have an impact on reducing the effects of climate change. Many ecosystems are degraded through the construction of human settlements and other anthropogenic activities, and the prevailing ecological functions are disturbed, including the natural carbon sequestration of the planet. Therefore, along with preventing greenhouse gas emissions, restoring the ecosystem can accelerate mitigation actions against climate change. Both green and blue infrastructure measures have given enough provision to incorporate such activities with urban planning. Therefore, the New Urban Agenda supports actions that build the resilience of urban inhabitants using ecosystem-based adaptations.

4. Discussion

International policies and frameworks of the SFDRR, the 2030 Agenda for Sustainable Development, the Paris Agreement, and the New Urban Agenda have considered ecosystems or nature-based solutions as one of the successful measures against climate change mitigation and disaster risk reduction. They have recognised the importance of incorporating ecosystems or nature-based solutions into the sustainable development process. Though none of the policies reviewed above used the exact term green and blue infrastructure, provision given for ecosystems or nature-based solutions strongly supports the adaptation of green and blue infrastructure in development planning.

The international policies and frameworks above are oriented to the ecosystems and their preservation and sustainability. From the ecosystem perspective, nature-based solutions have been adopted by many countries in their national and local level disaster risk reduction applications. However, as mentioned above, they have not used the exact terminology of green and blue infrastructure. The purpose of adopting green and blue infrastructure is to preserve, conserve, and restore natural environmental processes [13,31], which supports the broader aspects of climate change mitigation [39], community resilience [127] and disaster risk reduction [161]. Therefore, it can be considered a nature-based solution which complements the ecosystems’ perspectives of the international policies and frameworks.

Adopting blue and green infrastructure measures can be quickly implemented through micro-level adaptation practices where the focus is on more local and individual ecosystems. Large-scale activities and projects may not be successful since the strategies must vary according to the environmental characteristics of the local ecosystem. For example, there can be set general guidelines on wetland restoration and preservation. Yet, specific strategies should vary according to the local environmental characteristics to receive the best results.

The policies also recognise the importance of assessing the prevailing risk prior to implementation. It will be much more accurate if the ecosystems’ perspectives can be incorporated into disaster risk assessment to give a holistic view. This will also provide a better understanding of which environmental functions are weak within the systems and which environmental functions should be strengthened through the green and blue infrastructure measures. Incorporating local knowledge to understand these environmental functions will be an added advantage for decision-makers. The international policies have recognised local communities and their knowledge as an essential factor in disaster risk reduction as well as in the development process. Local communities can also engage in the implementation of green and blue infrastructure measures and even in the monitoring and maintaining processes. It will give them more accountability for sustaining their local communities from disasters.

It was further mentioned that strong legal background, institutional support, and stakeholder collaboration are essential when integrating green and blue infrastructure measures in development strategies. Each development project must have minimum impact on the ecosystem and its functions. Therefore, EIAs should be firm and legally backed by the authorities. If all development strategies can incorporate sustaining ecosystems as part of their strategic plans, disaster risk reduction and mitigation will not be hard to achieve. Therefore, risk-informed sustainable development practices should adhere to ecosystem resilience under an integrated framework for DRR.

The SFDRR has supported the above-mentioned areas for better preparedness for disaster risk reduction. As mentioned earlier, the policy has not directly mentioned the terms of green and blue infrastructure, yet provided sufficient guidelines for ecosystems-based approaches where green and blue infrastructure can be successfully integrated.

The 2030 Agenda for Sustainable Development directly supports the environment, ecosystems, and ecosystem services. Environment, ecosystems, and ecosystem services support all anthropogenic activities of social, cultural, and economic wellbeing [162,163]. Therefore, ecosystem-based approaches seem one of the best strategies to achieve these goals and targets. The literature has highlighted the importance of incorporating ecosystem-based approaches in decision making for development in support of sustainable development goals [23,163,164]. Many countries have already adopted ecosystem-based approaches, yet the number of implemented projects seems minimal.

To incorporate the ecosystem- or nature-based approach into development practices, decision makers and planners must have a sound knowledge about how ecosystems function and the interrelated sub-systems of these ecosystems. Furthermore, they should understand how the changes in development practices can disrupt the balance of natural processes, which can also lead to disastrous events. The United Nations have stressed the holistic approach to sustainable development planning where ecosystems are integrated [165]. However, as highlighted by Wood 2018, the issue remains in integrating these ecosystems-based holistic approaches into local development planning activities and national policies. Therefore, though it seems easily possible to integrate ecosystem-based approaches such as green and blue infrastructure measures into development practices on a global scale, the national policies are not yet ready to embrace and change along with them.

Therefore, the 2030 Agenda for Sustainable Development guidelines need to be translated into local policies, and operational strategies should be developed to successfully implement green and blue infrastructure measures.

The Paris Agreement has provided a mechanism to implement these initiatives on development activities within the agreement. It highlights stakeholder collaboration, capacity building, climate change education and awareness, international partnerships and much more. It also emphasises monitoring and evaluation mechanisms of the implemented activities where national inventories and progress monitoring on implemented activities are considered essential. However, these mechanisms should include the ecosystem-based framework under all aspects where ecosystem resilience is stressed upon.

To integrate DRR and climate change adaptation and mitigation actions into urban planning, the ecosystem resilience frameworks are highly useful in the planning process. The New Urban Agenda has recognised this importance and highlighted that, through green and blue infrastructure measures, effective territorial planning with nature-based solutions can be achieved productively. Furthermore, green and blue infrastructure facilities also enhanced the resilience-based and climate-effective design of spaces in urban planning where more greenery and water fractures were incorporated, aligning with ecosystem functions. Therefore, the New Urban Agenda provides a strong base for incorporating green and blue infrastructure measures into urban development activities.

The New Urban Agenda is open to new and feasible urban planning solutions with climate change mitigation and disaster risk reduction aspects. It highlights investing in infrastructure where sustainable solutions can be provided. It also discusses resilience building codes, sustainable energy, and transportation management practices from the development perspective. Green and blue infrastructure measures can address all these matters and provide feasible solutions with sustainable urban planning. No harm will come to urban cities if they adopt green and blue infrastructure measures to sustain their urban ecosystems and functions. It will be beneficial in reducing the disaster risk by making cities resilient.

It is important to focus on green and blue infrastructure under the ecosystems-based approaches through the lenses of urban development planning. However, focusing on ecosystems preservation, conservation, and restoration may not achieve the long-term goals of making resilient communities resilient and reducing the disaster risk. Integrating green and blue infrastructure can be focused not only on ecosystem preservation, conservation, and restoration but also on the broader perspectives of ecosystem services, agro-ecosystems, micro- and macro-environmental systems, and cascading and compound impact on human wellbeing. This can be achieved through integrated spatial planning for sustainable development.

Despite the support given by international policies and frameworks, translating them into local context seems one of the issues faced by the decision makers. Though the international policies are developed with up-to-date knowledge, and updated through the lessons learned, local development models and frameworks seems lacking or delayed in the implementation [36]. Many local development models are outdated and do not contain state-of-the-art knowledge [166]. One good example would be the sustainable development goals, where local applications seem delayed past the expected timelines, especially in developing nations [167].

Among many other reasons, top-down approach [83], trust issues [168], and macro models and frameworks [169] are three of the highlighting cases for a lack of localization and contextualization of the international policies and frameworks. The top-down approaches seem to create distance between the beneficiaries and the decision makers, since beneficiaries are not aware of how the decision has been made and why [29]. It can cause trust issues, where local authorities and communities do not trust in the policies and frameworks suggested under the top-down approach. In contrast to that, the bottom-up approach allows beneficiaries to take part in the decision-making process and give their input towards the decision [170]. Therefore, local authorities and communities tend to trust the process, which makes it easier to implement the policy decisions within the local contexts. However, it is always best to combine both approaches since it incorporates current input and prior knowledge and expectations where localization of the policy decisions is specific to that local context [171].

The application of macro approaches or the holistic models discourage localization of the international policies and frameworks [120,172]. Macro approaches or the holistic model may not reflect the exact local conditions and dynamics [173]. Especially in developing nations, authorities sometimes try to implement macro-scale models of another nation or a region within their local contexts without proper customization. This will again lead to trust issues, where local communities and decision makers do not collaborate with the policy decisions. Therefore, when it comes to implementation of the international policies and frameworks into local contexts, it is always important to tailor them according to the local conditions [127,174].

In many developing nations the development process is supported by international aid and Non-Governmental Organisations (NGOs). A lack of collaboration among institutions has caused trust issues amongst almost all sectors, where the private sector does not trust the government, the government does not trust the private sector, communities do not trust the government, and so on [168]. This will again adversely affect localisation of the international policies and frameworks. Therefore, strengthening collaboration among all stakeholders including communities, private and public sectors, NGOs, and other international bodies is needed for better localisation of international policies and frameworks [45,175]. Establishing appropriate linkages between stakeholders will provide better platforms to translate the global policies and frameworks into local level decision making [176].

Another challenge of localisation is the bureaucracy among national or local institutions [33]. Sometimes the influence of the politicians supports the bureaucracy, so that they implement or translate the facts which are only favourable for the officials or the politicians. This may cause a lack of knowledge transfer from global level to local level decision makers and communities [177]. Therefore, reducing bureaucracy and enhancing knowledge sharing through research collaboration which involves all stakeholders including the beneficiaries, will strengthen the localization of international policies and frameworks with proper decision making [178]. To do that, participatory approaches may be one of the best approaches to integrate [36]. Such participatory approaches can harness the civic capacities, which can be integrated into custom localisation of the international policies and frameworks towards community resilience [168].

Through building trust among stakeholders, prioritising local and cultural competencies, and adaptive change management, localization of international policies and frameworks can be achieved productively. Moreover, through new partnerships and new models, countries will be able to support long term localization of the international policies and frameworks for making communities resilient.

5. Conclusions

International policies and frameworks have a crucial role in guiding, supporting and developing local, regional, and national DRR strategies. These policies are aimed at decisionmakers to provide initial guidance and a baseline towards better planning for local, regional, and national level DRR. This will provide better preparedness and strengthen local communities’ resilience, regardless of their level of development. The recent approaches of DRR are focused on ecosystems or nature-based solutions where environmental preservation, sustainability and protection are considered essential segments under the development activities. The review emphasises that the guidance and the directions towards better integration of ecosystems or nature-based solutions are given in the international policies and frameworks discussed in this paper. Therefore, green and blue infrastructure measures can be introduced under the ecosystems or nature-based solutions for better and more productive disaster risk reduction, especially among urban agglomeration. However, integrating them into local policies and translating them into practice seems lacking behind.

This study further clarifies how important the ecosystems- or the nature-based solutions are in urban development, and how policies have extensively supported them. It further pointed out the potential of integrating green and blue infrastructure measures under each policy and framework discussed within the analysis. This study therefore supports the decision makers to identify how green and blue infrastructure measures can be supported by the international policies and frameworks related to disaster risk reduction, sustainable development and urban planning for better preparedness among urban communities.