Regulating urban surface runoff through nature-based solutions – An assessment at the micro-scale. Zölch,T, Henze, L, Keilholz, P & Pauleit, S. Environmental Research, Volume 157, August 2017, Pages 135–14.
- Runoff after heavy rain events accounts for approx. 95% of total precipitation in highly sealed urban areas.
- By enhancing water storage capacities green infrastructure reduces runoff by max. 14.8% compared to the baseline.
- Green roofs and trees both show to be effective but due to different functions.
- The reduction of runoff is larger with higher shares of green cover in the case area.
Urban development leads to changes of surface cover that disrupt the hydrological cycle in cities. In particular, impermeable surfaces and the removal of vegetation reduce the ability to intercept, store and infiltrate rainwater. Consequently, the volume of stormwater runoff and the risk of local flooding rises. This is further amplified by the anticipated effects of climate change leading to an increased frequency and intensity of heavy rain events. Hence, urban adaptation strategies are required to mitigate those impacts.
A nature-based solution, more and more promoted in politics and academia, is urban green infrastructure as it contributes to the resilience of urban ecosystems by providing services to maintain or restore hydrological functions. However, this poses a challenge to urban planners in deciding upon effective adaptation measures as they often lack information on the performance of green infrastructure to moderate surface runoff. It remains unclear what type of green infrastructure (e.g. trees, green roofs), offers the highest potential to reduce discharge volumes and to what extent.
Against this background, this study provides an approach to gather quantitative evidence on green infrastructure’s regulation potential. We use a micro-scale scenario modelling approach of different variations of green cover under current and future climatic conditions. The scenarios are modelled with MIKE SHE, an integrated hydrological modelling system for building and simulating surface water and groundwater flow, and applied to a high density residential area of perimeter blocks in Munich, Germany. The results reveal that both trees and green roofs increase water storage capacities and hence reduce surface runoff, although the main contribution of trees lies in increasing interception and evapotranspiration, whereas green roofs allow for more retention through water storage in their substrate. With increasing precipitation intensities as projected under climate change their regulating potential decreases due to limited water storage capacities. The performance of both types stays limited to a maximum reduction of 2.4% compared to the baseline scenario, unless the coverage of vegetation and permeable surfaces is significantly increased as a 14.8% reduction is achieved by greening all roof surfaces.
The authors conclude that the study provides empirical support for the effectiveness of urban green infrastructure as nature-based solution to stormwater regulation and assists planners and operators of sewage systems in selecting the most effective measures for implementation and estimation of their effects.
Urban green infrastructure as nature-based solution to regulate surface runoff becomes increasingly important, as climate change and urbanisation alter the urban water balance. The present study assessed the performance of two urban green infrastructure (UGI) types, trees and green roofs, on relevant hydrological processes, especially surface runoff. The two measures were applied in scenarios of different greening quantity and for heavy rain events of different intensities as projected for the future. This scenario approach revealed that both trees and green roofs contribute positively by interception, evapotranspiration and infiltration. Differences in their performance showed to be dependent on the greening quantity, share of permeable surfaces leaf area index (LAI) and finally, intensity of the rainfall event. Generally, their effectiveness remains low under heavy rain events, unless a significant proportion of the case area is greened to provide sufficient water storage capacities (Artmann, 2014).
For urban planning the presented results have practical implications for the selection of UGI types to reduce surface runoff volumes and in consequence reduce discharge loads, the sewage system has to handle. An effective nature-based solution increases the storage capacities within the area of interest as much as possible, while using open spaces that have not been used previously and/or while providing benefits to other areas of urban planning. Trees increase the storage capacity mainly by intercepting and evapotranspiring rainwater, their infiltration capacity is limited to the tree pits. But trees can normally not be implemented in large quantity in dense urban areas due to their requirements of open space. Green roofs on the other hand, provide storage capacity mainly by retaining rainwater in their substrates and can be implemented at larger scale on previously unused roof surfaces.
Furthermore, both types are multifunctional and can provide co-benefits for urban planning. The approach represents a first step in allowing planners as well as operators of sewage systems to estimate reductions in runoff volume when locally implementing UGI measures. These estimations could be further improved by integrating additional stormwater management practices and the drainage system in more detail into the modelling setup. Thus, conducting a larger systematic study of UGI scenarios would allow for including e.g. more UGI types, different species and LAI values as well as planting conditions. Such a study could enhance the provision of empirical evidence for climate resilient urban planning.
In March 2013 the Landscape Institute published an updated Mission Statement, ‘Green Infrastructure: An integrated approach to land management’. The document was described as,
“An opportunity to showcase a range of successful strategic GI work and completed
projects. The aim is to give public and private sector bodies, clients and natural and built environment professionals fresh insights into the benefits GI can bring by creating multifunctional landscapes and show how people can collaborate to deliver it.”
Melbourne trees are under threat, with almost 44% projected to disappear in the next 20 years, so the city had to come up with a plan to includes increasing canopy cover and improving biodiversity, vegetation and soil moisture. The city was received an award of excellence for research, policy and communication from the Australian Institute of Landscape Architects, with judges calling their ‘Urban Forest Strategy – Making a Great City Greener 2012-20132′ a glowing example of ‘how to transform policy into practice to create a distinctive and liveable city’.
The City of Melbourne’s urban forest will be resilient, healthy and diverse and will contribute to the health and wellbeing of our community and to the creation of a liveable city. To link to full text click here
Melbourne is currently facing three significant challenges: climate change, population growth and urban heating placing pressure on the built fabric, services and people of the city. A healthy urban forest will play a critical role in maintaining the health and liveability of Melbourne. Over the next 20 years and beyond, Melbourne will experience a changing climate, becoming increasingly warm, dry, and liable to more frequent extremes of heat and inundation. The city’s urban heat island effect will intensify.
One of the important functions of the urban forest is to provide shade and cooling. Increased canopy coverage throughout the city will minimise the urban heat island effect and improve thermal comfort at street level for pedestrians. Increased water sensitive urban design will play an important role in managing inundation and providing soil moisture for healthy vegetation growth, as well as enhancing the city’s ecology.
Climate change science and international urban forestry research both indicate that a range of threats facing the urban forest will increase in the future, particularly vulnerability to pests, disease and extremes of weather. Melbourne’s residential, worker and visitor populations will increase. An associated growth in the urban forest, ‘green infrastructure’ and ‘ecosystem services’ would respond to these pressures, reduce the cost of grey infrastructure and improve the quality of the urban environment.
The recent period of drought and water restrictions triggered irreversible decline for many trees. This exaggerated the age-related decline of many significant elms and other trees. Modelling shows that within the next ten years, 23% of our current tree population will be at the end of their useful lives and within twenty years this figure will have reached 39%. To guide future planting, a series of tools and programs have been, and will continue to be, developed. Building the urban forest as a living ecosystem and ensuring that it provides the maximum benefits for our communities will rely on smart species selection, improving soil moisture retention, reducing stormwater flows, improving water quality and re-use, increasing shade and canopy cover, and reducing infrastructure conflicts.
Urban forestry is entering a new era in Australia and this strategy highlights how important it is, particularly in context of enhancing liveability and adapting to predicted climate change. An urban forest provides a multitude of benefits for ecosystems, the economy, and community health and wellbeing.
Photograph source: City of Melbourne
Principles, strategies & targets
The vision is of a healthy, resilient and diverse urban forest that contributes to the health and wellbeing of our communities, and to a liveable city that will create better urban environments for everyone. The principles outlined in the strategy are to guide decision-making to create a future forest. The strategy highlights proactive and adaptive management, and will transform an asset that has a current amenity value estimated at $700 million and a future value that is potentially priceless.
The strategy’s guiding principles are to:
- mitigate and adapt to climate change
- reduce the urban heat island effect
- become a ‘water sensitive’ city
- design for health and wellbeing
- design for liveability and cultural integrity
- create healthier ecosystems
- position Melbourne as a leader in urban forestry
The strategies and targets proposed to achieve this vision are:
- Strategy 1: Increase canopy cover Target: Increase public realm canopy cover from 22% at present to 40% by 2040.
- Strategy 2: Increase urban forest diversity Target: The urban forest will be composed of no more than 5% of any tree species, no more than 10% of any genus and no more than 20% of any one family.
- Strategy 3: Improve vegetation health Target: 90% of the City of Melbourne’s tree population will be healthy by 2040.
- Strategy 4: Improve soil moisture and water quality Target: Soil moisture levels will be maintained at levels to provide healthy growth of vegetation.
- Strategy 5: Improve urban ecology Target: Protect and enhance a level of biodiversity that contributes to a healthy ecosystem.
- Strategy 6: Inform and consult the community Target: The community will have a broader understanding of the importance of our urban forest, increase their connection to it and engage with its process of evolution.
A new framework has been developed to assess how effective Flood Emergency Management Systems (FEMS) are in Europe. Examining FEMS in five European countries, this study highlights the strengths and weaknesses of existing systems and makes recommendations for improving their effectiveness, particularly in relation to institutional learning, community preparedness and recovery.
Source: Gilissen, H. K., Alexander, M., Matczak, P., Pettersson, M. & Bruzzone, S. (2016). A framework for evaluating the effectiveness of flood emergency management systems in Europe. Ecology and Society, 21(4):27. DOI: 10.5751/ES-08723-210427. This study is free to view at: www.ecologyandsociety.org/vol21/iss4/art27/
Climate change is expected to increase the frequency and severity of floods and society must be able to respond to this evolving threat. To achieve this, FEMS, which are designed to ensure that emergency professionals are prepared for floods, should include assessments of risk to underscore flood-specific emergency planning, promote inter-agency working, professional training, facilitate community preparedness and support immediate recovery activities, such as restoring essential services and supplies. Whilst FEMS are embedded within broader legal and policy frameworks for integrated emergency management and civil contingencies, the pressing challenges posed by floods provide a strong case for examining FEMS in isolation.
This study, partly conducted under the EU STAR–FLOOD [see reference below] project, presents a new framework to assess and monitor the effectiveness of FEMS in European countries from legal and public-administration perspectives. To build the framework, the researchers conducted an appraisal of existing international academic and grey literature published since 1970, relating to emergency and disaster-management systems for any type of hazard at international, national and subnational levels. This informed the identification of seven key indicators that could be used to evaluate the performance of processes and actions in emergency flood management:
- Planning: development of an emergency plan to establish priorities, actions and decision-making in the event of a flood emergency;
- Institutional learning: procedures to be in place to promote learning at frequent intervals (e.g. post-event reviews and inquiries, opportunities for knowledge exchange across responding agencies);
- Exercising emergency arrangements: planning and operational procedures should be tested at multiple scales;
- Joined-up working: distribution of responsibilities within and between emergency actors must be clearly defined, effectively coordinated and collaborative;
- Community preparedness: should be supported by emergency professionals (e.g. raising risk awareness and direction on what to do when a flood occurs);
- Provision of resources: (financial, human resources, equipment, and decision-support tools) needs to be ensured and arrangements need to be established for sourcing and allocating additional resources as required;
- Recovery-based activities: arrangements should be in place to support evacuation, for temporary housing, restoration of essential services, help for businesses to function, dealing with physical damage and management of environmental impacts, such as pollution and contamination.
To put this framework into use, the researchers outlined key benchmarks against which a country’s performance can be scored; for this, they used a scale of one to five (absent/minimal, emerging, moderate, significant and outstanding).
The researchers then collected information from a variety of sources to evaluate the extent to which benchmarks are achieved in five European countries: France, the Netherlands, Poland, Sweden and the UK (specifically England). The information was drawn from the analysis of emergency-management policy documents and legislation, as well as stakeholder interviews and workshops with key practitioners and policymakers involved in emergency management and flood-risk management more broadly (for example, government departments, municipal and local authorities, and emergency responders).
The National Flood Emergency Framework for England (December 2014) sets out the government’s strategic approach to achieving the aims set out below and is intended for use by all those involved in planning for and responding to flooding from:
- the sea
- surface water
- groundwater and
The concept of a National Flood Emergency Framework was promoted by Sir Michael Pitt in his report on the summer 2007 floods. Its purpose is to provide a forward looking policy framework for flood emergency planning and response. It brings together information, guidance and key policies and is a resource for all involved in flood emergency planning at national, regional and local levels. It is a common and strategic reference point for flood planning and response for all tiers of government and for responder organisations.
More precisely, the purpose of the Framework is to:
- ensure delivery bodies understand their respective roles and responsibilities
- give all players in an emergency flooding situation a common point of reference – bringing together information, guidance and key policies in a single planning document
- establish clear thresholds for emergency response arrangements
- place proper emphasis on the multi-agency approach to managing flooding events
- provide clarity on the means of improving resilience and minimising the impact of flooding events
- provide a basis for individual responders to develop and review their own plans and
- be a long-term asset that will provide the basis for continuous improvement in flood emergency management
Responding to floods in Europe: new framework assesses effectiveness of Flood Emergency Management Systems
Of the five countries, England’s FEMS were found to be the most effective, with all seven indicators achieving significant or outstanding ratings. In the absence of statutory rights to flood protection, a diversified approach to FEMS has existed for over 65 years in England; thus, flood emergency management has served as a crucial strategy for minimising the consequences of flood events. Dedicated policy for flood emergency management is seen, with multi-agency flood plans as a standard component of common practice. Moreover, formal legal mechanisms underpin effective integrated working between emergency responders (e.g. duties to cooperate, and formation of Local Resilience Forums) and certain responders are actively involved in activities to enhance community preparedness for floods.
In Sweden, given the low distribution of flood risk, flood protection management is organised at the local or municipal level on a relatively ad hoc basis by those municipalities affected by flooding, rather than being established at the national scale. Whilst this is considered to be an efficient strategy and provides the necessary flexibility for municipalities to adapt to local risks, there is a risk that some areas may be neglected. Moreover, the lack of national arrangements and supportive mechanisms may make it difficult for certain municipalities to mobilise the necessary resources, according to the researchers.
In France, emergency management has evolved over the past few decades and has been integrated into local disaster-management planning and policies, in line with broader initiatives towards decentralised governance. ‘Professionalisation’ of the public is one of the major aims of the French FEMS, where voluntary fire brigades play a key role. Municipalities can optionally call in voluntary civil-protection reserves to assist in response activities. Efforts to enhance community preparedness are becoming nationally more consistent. However, recovery guidance and regulation varies regionally and this is an area for improvement identified by the researchers.
In the Netherlands, historically, there has been a strong tradition of flood defence and protection, with a statutory right to be protected by the state from floods. Nonetheless, recent efforts have sought to diversify the range of strategies implemented, in order to manage flood risk more holistically and address the country’s increased vulnerability to flooding under climate change. However, certain aspects of flood emergency management (i.e., institutional learning, community engagement, and recovery) are less well developed. Moreover, the organisational structure requires some improvement, the researchers say.
In contrast to the other countries, the FEMS in Poland is still emerging in several aspects, particularly with regard to institutional learning, community preparedness and recovery-based activities. The occurrence of significant flood events (1997) has prompted establishment of the crisis-management institutional framework and efforts to improve the effectiveness of FEMS, yet gaps are seen between policy and practice. The researchers identify small-scale examples of good practice, such as the ‘flood leaders’ initiative in Wroclaw, but say these are yet to be scaled-up and implemented nationwide.
Although the researchers found that all countries had different approaches to flood-risk management, shaped by diverse political and administrative cultures and socio-economic conditions, they have produced some common recommendations to improve the effectiveness of FEMS:
- Specific provisions for flood emergency management could prove beneficial in countries where flood risk is projected to increase. Lessons could be learned from the multi-agency flood-planning groups and subgroups within Local Resilience Forums, as seen in England, which provide further clarity on roles and responsibilities at times of flood emergencies;
- National guidance could be provided for flooding in countries with a low risk of flooding, or where flood-risk areas are widely distributed, to help deliver consistent support and establish good practice at the local level;
- Specific training for flood emergencies is necessary to test planning, responsive procedures and communication systems, as well as helping to raise community awareness of flood risks;
- Efforts to encourage community preparedness require better communication of flood risks and need to be situated alongside wider efforts to normalise adaptation within society.
- STAR-FLOOD (STrengthening And Redesigning European FLOOD risk practices Towards appropriate and resilient flood risk governance arrangements) was supported by the European Commission under the Seventh Framework Programme. http://cordis.europa.eu/result/rcn/153561_en.html
Overview: A new Town and Country Planning Association (TCPA) report for the Joseph Rowntree Foundation (JRF) is warning that the majority of new local plans in England are failing to cut carbon emissions and to plan for the scale of severe weather predicted over future years. The report Planning for the Climate Challenge? Understanding the performance of English Local Plans, found that 70% had no carbon reduction targets or any way of monitoring their progress with carbon reduction. The study established the extent to which climate change mitigation and adaptation are reflected as priorities in local plan policy in England. Click here to download the full report.
The spatial planning system provides for the democratic regulation of the built environment in the public interest, and has the potential to make a major contribution to both reducing carbon dioxide emissions and preparing for the growing impacts of climate change.This report reveals that the planning system is failing to fulfil this potential.
Despite the increasing intensity and frequency of climate-related impacts, local plans are not delivering on the basic standards set out in national law and policy for either mitigation or adaptation. To deliver the fundamental change required, climate change must be placed front and centre of the policy priorities of the spatial planning system. Only a radical refocusing of the system will meet the challenges of climate change, now and in the future.
The study underpinning this report explored how local plans published since the National Planning Policy Framework was produced in 2012 are addressing climate change. Drawing on a sample of 64 local planning authorities in total, and based on an analysis of local planning documents, a survey of local authority planners and four more-detailed, area-based case study examinations, the study established the extent to which climate change mitigation and adaptation are reflected as priorities in local plan policy in England.
The study found that local plans in England are not dealing with carbon dioxide emissions reduction effectively, nor are they consistently delivering the adaptation actions necessary to secure the long-term social and economic resilience of local communities. There was a wide variety of practice: there were some examples of positive responses, but, taken as whole, it is clear that since 2012 climate change has been de-prioritised as a policy objective in the spatial planning system. The large-scale failure to implement the clear requirements of national planning policy is a striking finding, as is the reduced capacity of the local authority planning service and the reduced capacity of Environment Agency to support the long-term plan-making process.
There are complex reasons for this situation – ranging from perceived contradictions in national policy to political signals from Ministers in the Department for Communities and Local Government and HM Treasury about the overwhelming priority to be given to the allocation of housing land. In addition, in many cases local plans do not meet national policy requirements on climate change but are still judged sound by the Planning Inspectorate. Underlying all of this is a crisis in resources in the local planning service which inhibits effective local policy-making.
The failure to use the planning system’s capability to help mitigate and adapt to climate change is inefficient, and is likely to lead to long-term avoidable costs to the economy. Conversely, there is a real opportunity to harness the system as a key local part of the national response to climate change. Fulfilling this potential requires, above all else, a signal from national government that climate change is a primary political, legal and policy priority for the local plan process.
- Climate change has been de-prioritised as a significant local planning policy issue.
- Policy and legislation on climate change are poorly understood.
- National policy as set out in the National Planning Policy Framework and in National Planning Policy Guidance does provide for a clear approach to climate change. However, it also contains policy on viability which prevents some key actions from being delivered. In addition, changes made by subsequent amendments to energy, zero carbon and sustainable urban drainage policies have made action on many climate change responses more difficult.
- The evidence-gathering, methodologies and policy-making used to address flood risk were far more sophisticated than the equivalent for climate mitigation or any other aspect of adaptation. Local plans deal with carbon dioxide emissions reduction vaguely, often without an explicit methodology for measuring reductions.
- LPAs are failing to plan for future climate change and therefore are not planning for the adaptation measures necessary to secure long-term social and economic resilience.
- The governance of climate change issues at the local level is complex and sometimes contradictory. LPAs are not supported by a national agency to secure national carbon dioxide emissions reduction objectives, while the specific challenge of flood risk is reliant upon the support of the Environment Agency.
- Planning requirements do not apply to a wide range of land uses, which affects local responses to climate change.
- Specific approaches to dealing with climate change are still novel to many local authority planners, and access to affordable training is a major issue.
- Climate-change-related policy outlined in local plans is generally short term and not sufficiently future-facing to deal with climate risk.
- The duty to co-operate among LPAs is overwhelmingly focused upon housing growth, with little to no emphasis placed on cross-boundary climate change issues. However, strategic co-operation on issues such as evidence-gathering is a major opportunity area for climate change work.
This report recommends ten actions for national and local government that could significantly and cost effectively improve the performance of local plans in relation to climate change:
Globally, 14 of the 15 hottest years on record have occurred since 2000. Climate change is set to increase the probability of flooding and put pressure on water availability in the UK. Periods of too much or too little rainfall are both likely symptoms of increasing global temperatures. These could happen back to back, as was the case in the first six months of 2012, the so-called “wettest drought on record”.
The Committee on Climate Change’s Adaptation Sub-Committee (ASC) new independent report to Government, ‘UK Climate Change Risk Assessment Evidence Report’ sets out the most urgent risks and opportunities arising for the UK from climate change.
Changes to the UK climate are likely to include periods of too much or too little water, increasing average and extreme temperatures, and sea level rise. The report concludes that the most urgent risks for the UK resulting from these changes are:
- Flooding and coastal change risks to communities, businesses and infrastructure.
- Risks to health, wellbeing and productivity from high temperatures
- Risk of shortages in the public water supply, and water for agriculture, energy generation and industry, with impacts on freshwater ecology.
- Risks to natural capital, including terrestrial, coastal, marine and freshwater ecosystems, soils and biodiversity.
- Risks to domestic and international food production and trade.
- Risks of new and emerging pests and diseases, and invasive non-native species, affecting people, plants and animals.
The opportunities for the UK from climate change include:
- UK agriculture and forestry may be able to increase productionwith warmer weather and longer growing seasons, if constraints such as water availability and soil fertility are managed.
- There may be economic opportunities for UK businesses from an increase in global demand for adaptation-related goods and services, such as engineering and insurance.
The impact of the recent vote to leave the European Union does not change the overall conclusions of the risk assessment. However, some individual risks may change if EU-derived policies and legislation are withdrawn and not replaced by equivalent or better UK measures. The Adaptation Sub-Committee will assess the implications of the EU referendum in its next statutory report to Parliament on the UK National Adaptation Programme, due to be published in June 2017.
Lord Krebs, Chairman of the Adaptation Sub-Committee of the Committee on Climate Change, said: “The impacts of climate change are becoming ever clearer, both in the United Kingdom and around the world. We must take action now to prepare for the further, inevitable changes we can expect. Our independent assessment today, supported by the work of hundreds of scientists and other experts, identifies the most urgent climate change risks and opportunities which need to be addressed. Delaying or failing to take appropriate steps will increase the costs and risks for all UK nations arising from the changing climate.”
“A GREENER COPENHAGEN IS A CLIMATE-PROOF COPENHAGEN: The Climate Adaptation Plan recommends that green spaces should contribute to adapting Copenhagen to cope with the weather of the future. A long-term, broad and focused effort to bring about a greener Copenhagen should be a preventive investment in a climate-proof Copenhagen with a high level of quality of life, health and satisfaction for the city’s population.”
Copenhagen Carbon Neutral by 2025, COPENHAGEN CLIMATE ADAPTATION
Copenhagen has made a cloudburst plan, which is currently being elaborated in cooperation with the Municipality of Frederiksberg. The work consists of planning a new cloudburst infrastructure as a whole to make Copenhagen and Frederiksberg more resistant to torrential rain.
“We have to act because torrential rain is going to hit us more frequently in the future. We are ready with the first three concrete plans that will protect the city’s residents and businesses from flooding. I think we should give priority to create new recreation areas rather than solve the whole challenge of new underground pipes. But it is important that the people of Copenhagen have a significant impact on the choice of solutions, “says Technical and Environmental Mayor Ayfer Baykal.
CASE STUDY: Tåsinge Plads, Copenhagen, Denmark – 7.500 m²
ADVISORS: Malmos, GHB Landskabsarkitekter, Orbicon, VIA Trafik Rådgivning, Feld Studio for Digital Crafts
DEVELOPER: Københavns Kommune
HANDLED RAIN WATER: 7.000 m²
PRICE: 2.000 kr per m²
CONTACT: René Sommer Lindsay
Projektchef Områdefornyelsen Skt. Kjelds Kvarter. firstname.lastname@example.org
Tåsinge Plads, Copenhagen, Denmark
Tåsinge Plads part of Copenhagen’s plan to survive the future effects of climate change. During heavy rains, the flowerbeds fill with water and wait to drain until the storm runoff subsides. The upside-down umbrellas collect water to be used later to nourish the plantings. Landscaping is designed to direct stormwater into underground water storage tanks. Above are bouncy floor panels where energy from ground level footfall pumps water through the pipes below.
Flemming Rafn Thomsen, founding partner Copenhagen-based landscape architects Tredje Natur, describes it as an example of how the job of climate change adaptation can be turned from a negative thing into a positive one. “Water is used as a resource to improve urban life,” Rafn Thomsen says. “We look at Copenhagen as a hybrid city where you can fuse nature, urban biology and human beings in a more appropriate balance.”
Copenhagen has been hit by two “100-year flood” events, in 2011 and in 2014. The Intergovernmental Panel on Climate Change predicts that this sort of extreme weather will become increasingly frequent in Denmark, with heavier downpours. Sea-level rise is a separate but related threat — according to research from the Niels Bohr Institute, the waters around Copenhagen could rise by up to 1.6 meters in the next 100 years.
Flowerbeds of Tåsinge Plads fill with water during heavy rains, while sculptures collect water to nourish plantings. Image: David Buchmann
Copenhagen has developed a Climate Adaptation Plan that relies mostly on a “green and blue” system approach where stormwater is dealt with at street level through a network of parks, cloudburst boulevards and retention zones rather than “gray” infrastructure” where water is redirected into the city’s existing subterranean sewer and drainage system. The latter would require doubling the city’s existing infrastructure to handle the higher expected volumes of rainwater by burying more and larger pipes to handle increased rain runoff.
Copenhagen’s council has approved plans for 300 surface-based solutions like those in Tåsinge Plads to be implemented over the next 20 years. “The ambition of the Climate Adaptation Plan is to get technical solutions above ground,” says René Sommer Lindsay, manager for project in the neighborhood around Tåsinge Plads. “So when it’s not raining, there is still value in the space.”
For Copenhagen, the “green and blue” approach was also the most affordable option. It is expected to cost US$1.3 billion — about half the price of more conventional “gray” upgrades. Doing nothing was also an option leading to more flood damage costing the city an estimated $2.3 billion over a 100-year period. The the Danish think tank Sustainia stated: “It is both a financially sound investment and one that increases quality of life.”
While water plays a central role in every one of the improvement projects, community engagement is very important. When the Tåsinge Plads project began in 2012, more than 10,000 people took part in community engagement projects. By building community gardens and art projects in the previously barren space, the community began to shape the square’s future by bringing some meaning to it.
A key element in the climate adaptation strategy of the City of Copenhagen is for achoice of solutions that emphasise that help to improve quality of life for the people of Copenhagen at the same time as being effective and economically justifiable. When methods are chosen for adaptation, there should be a focus on the greatest possible number of secondary gains and possible synergy with other planning. Desired secondary gains are:
• More recreational opportunities
• New jobs
• Improved local environment with more green elements
‘People, Politics and the Planet: Any Questions?‘
6:00 p.m., 21 July 2016 at The Royal Geographical Society, 1 Kensington Gore, London, SW7 2AR.
Join the Sibthorp Trust, the British Ecological Society and the Royal Geographical Society (with IBG) for the first post-referendum public debate on the future of environmental policy in the UK following the vote to leave the European Union, chaired by Jonathan Dimbleby.
Confirmed panellists include:
- Baroness Kate Parminter, Liberal Democrats, Spokesperson for Environment and Rural Affairs
- Natalie Bennett, Green Party, Leader
- Kerry McCarthy MP, Labour
- Stuart Agnew MEP, UKIP, Agriculture Spokesperson
The UK has voted to leave the European Union, launching the country into a period of uncertainty as a new relationship with Europe and the world is negotiated. The EU frameworks that have underpinned much of our environmental policy and legislation – from agriculture to protected areas – are no longer assured.
Yet the challenges of climate change and biodiversity loss will lose none of their urgency. What will environmental policy in the UK look like outside of the European Union? What threats and opportunities does ‘Brexit’ pose for the environment? How will we tackle international challenges under a new political agreement?
The debate will be followed by a drinks reception, and the opportunity to view the Atkins CIWEM Environmental Photographer of the Year exhibition.
Book your ticket now at http://peoplepoliticsplanet.eventbrite.com. Tickets are available at £10 for BES/RGS-IBG members and concessions, or £20 full price.