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Green structure; Renewal and restructuring of neighborhoods
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4. Scientific Master Thesis
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3 The Hague 2040+ AN INTEGRATED APPROACH TOWARDS HEAT PROOF CITIES
Msc. thesis Delft University of Technology
© 2015 Klaas Sijmen Akkerman Published as a graduation research thesis at the Faculty of Architecture and the Build Environment under the chair of Urban Metabolism at the Technical University of Delft, The Netherlands.
All rights remain with the author.
Cover image by Frans Snijder, edited by author.
Template by Luuk Graamans, adapted by author.
4 The Hague 2040+
AN INTEGRATED APPROACH TOWARDS HEAT PROOF CITIES
Master of Science (MSc) thesis The Hague 2040+ - An integrative approach towards heat proof cities.
03-07-2015
Author Klaas Sijmen Akkerman Student number 1502182
Mentors Dipl.ing. Alexander Wandl, Msc. Urbanism ̶ Researcher Environmental Technology & Design
Dr.ir. Frank van der Hoeven Urbanism ̶ Associate Professor Urban Design
External committee member Ir. Ype Cuperus AE+T ̶ Associate Professor Architectural Engineering
Delft University of Technology, Faculty of Architecture and the Built Environment, Department of Urbanism.
5 6 Executive Summary
Globally we are facing a changing climate resulting in more extreme weather; more heatwaves, extreme drought, and heavy rainfall will be common events during the 21st century. Data collected by National Oceanic and Atmospheric Administration (NOAA) and the Japanese Meteorological Agency, published by Bloomberg revealed that 2014 was the warmest year ever on record. Temperatures during the first half of 2015 have already beaten last year’s records (Bloomberg, 2015). Increasing temperatures, especially during hot summers have a huge impact on our cities; since urban heat islands will be formed. This means that cities accumulate heat and consequently are warmer than their rural surroundings (Salcedo Rahola, Van Oppen, & Mulder, 2009a). This causes heat stress which has negative effects on human health and an increased demand for resources (Kleerekoper, 2009; Van der Hoeven & Wandl, 2013).
In order to adapt to these changes, cities all around the world are developing climate adaptation strategies. In this context The Hague has responded reluctantly. This is alarming since research on surface heat islands in Dutch cities by TNO has revealed that temperatures in The Hague are on average 8,6˚C higher than outside the city, making The Hague the warmest city in The Netherland (Hove et al., 2011).
A climate assessment carried out in this research on The Hague reveals that especially the dense city core and Scheveningen are extremely vulnerable for urban heat. The vulnerability is mainly determined by the lack of green structure, high population densities, and low rated liveability. At the moment vulnerable groups, in this case elderly people, still live outside the vulnerable areas. However, demographic predictions show that the number of elderly in the warmer areas will rapidly increase until 2040 (Starmans & Vermeulen, 2012).
Several (international) research institutes and programs agree that in order to execute an effective climate plan, an integrated approach is needed (“Climate Proof Cities,” 2015; IPCC, 2009). This implies that consideration has to be paid to opportunities already present and whether adaptation- or mitigation measures can be integrated in existing development strategies.
7 In order to develop an integrated climate adaptation strategy an assessment on The Hague’s spatial planning-policies is performed. From this it can be concluded that The Hague does not possess any plans regarding urban heat mitigation in her spatial planning or climate plans. Even more so, current plans to increase built density in the city core will even increase heat problems. Actions to improve the city’s green structure are planned in areas where they have no contribution to the mitigation of heat stress. Nevertheless these and other planned actions and relating policies do offer possibilities for heat mitigation, albeit that locations or execution have to be changed.
Integration of climate adaptation strategies in other policies is already done in other cities. A study of Singapore shows that implementation and maintenance of extensive green structures not only increases liveability of the city, but can also be used to attract foreign investment. Stuttgart has a long tradition with environmentally aware development. The green structure surrounding the city is used to ensure inflow of cool and fresh air into the city. In order to optimize airflow, guidelines for buildings and regulations for open areas have been recorded in the city’s climate atlas.
Three design studies have been executed to develop a strategy for heat mitigation in The Hague. The first study, Green The Hague, shows the development of a green structure in both public and private areas. Narrow streets in the city core often leave no room for planting of trees, but private inner courts do. Green roofs also play part in this study, as they can be installed on the flat roofs in the warmer parts of the city. In all studies collaboration between the municipality, home owners and individuals is crucial. This is already enforced by the city’s Structure Vision.
Dense The Hague, the second study, shows that further intensification of land use, as planned by the municipality in the city core, is unwanted. Since the municipality prefers to develop close to the city centre, the International Zone and Haagse Hout have been appointed as development areas. The extension of the city-heating networks, as proposed by the Housing Vision, offers opportunity to re-arrange (underground) infrastructure and restructure public space. Creating room for the development of green structure must be made.
8 Executive Summary
Finally, Healthy Ageing in The Hague shows demographic trends towards the ageing of The Hague’s population. Currently the elderly live outside the warmer parts of the city, with the exception of Scheveningen. By 2040 over 20% of the population living in the warmer areas will be over 65, putting the elderly at risk. National policy prescribes that people have to be able to live as long as possible in their own houses. To enable this, houses need to be adapted. These adaptations can be combined with renovation and the execution of the measures for mitigation as proposed in the other studies.
The synthesis of these three studies has resulted in a set of key actions The Hague can adopt to execute her ambitions to effectively mitigate urban heat. The key projects are:
◊ City-heating networks; installation of city-heating should be combined with restructuring of (underground) infrastructure to allow more room for green structure in streets. ◊ Urban renewal; creates opportunity to restructure public space to make room for ‘refuge zones’ and green structure. ◊ Accessible water; inner city water can be made accessible to reduce heat stress on hot days. This can be combined with the increase of water retention areas. ◊ Green with functions; combining the development of a new green structure with functions can create feasible business cases. ◊ Heat plan; communication and education are the cheapest and most effective ways to prepare people for periods of sustaining heat.
9 10 Preface
This thesis focusses on exploring ways to integrate climate adaptation measures related to urban heat in municipal spatial planning. The thesis is the final part of my graduation project. In this graduation project I continue the work done by Bart van den Heuvel and Laura Kleerekoper in their theses The Hague’s Options Against (2009) Urban heat and Design Principles For Urban Heat (2009).
In 2014 I conducted a research on healthy living environments, De Gezonde Stad (Akkerman, 2014) during an internship at engineering company Witteveen+Bos in The Hague. Starting point for that research was the fact that currently over 50% of the world population lives in cities. This number is expected to increase to over 75% in the next 40 years (United Nations, 2012). This development will have major impact on the way we use land and resources. The question was: how do we keep our living environment healthy; how to keep out cities and homes liveable, connected and safe?
The conclusion of that research was that these questions can only be answered by approaching them in an integrated way. Witteveen+Bos and Ad de Bont, urban de- signer at the Technical University Eindhoven in 2013 came to the same conclusion:
“A healthy city offers an attractive, liveable and safe living environ- ment for its residents. A healthy city is a city that seduces to a healthy lifestyle. A city in which plenty of walking and cycling takes place. A city in which there is enough room the move and play around and which offers meaningful parks and public spaces. Healthy Design is often biased towards a specific focus, such as cycling, green, sports or an environmental view. An integrated approach is required (internal memorandum (Akkerman, 2014).”
Urban heat was a returning issue in my research and it caught my attention. With the main conclusion of the research being that an integrated approach is needed to keep our cites healthy, I started to wonder what an integrated approach would contain for urban heat islands.
11 12 Contents
I Problem Analysis 16
1 Introduction 17 1.1 Urban Heat Island 17 1.2 Climate change 18 1.3 General adaptation strategies 19 1.4 Urgency for climate adaptation in The Hague 20 1.5 Objective of the research 21 1.6 Research question 21 1.7 Outcome 21
2 Research design 23 2.1 Part 1 - Problem Analysis 23 2.2 Part 2 - Mitigation and Adaptation Strategies 23 2.3 Part 3 - The Case of The Hague 25 2.4 Part 4 - Integrated Strategy 25
3 The Hague and Urban Heat 27 3.1 Urban Heat Island The Hague 27 3.2 City characteristics influencing the heat island of The Hague 28
II Mitigation and Adaptation Strategies 30
4 Integrated Strategies 31 4.1 Meetings with The Hague and Rotterdam 31 4.2 International Panel for Climate Change 32
5 Research Programs 35 5.1 Vulnerability 35 5.2 Measures 36 5.3 Governance 37
6 Comparative analysis 39 Methodology 39 Singapore 40 Stuttgart 44 Amsterdam 48
13 III The Case of The Hague 52
7 Climate assessement 53 7.1 Indicating Warmer Areas 53 7.2 Data Collection 53 7.3 Vulnerable Neighbourhoods 54 7.4 Conclusions on Vulnerable Places 55
8 Policy Assessment The Hague 2040 63 8.1Policy documents 63 8.2 Conclusions and Conflicts of Interest 70
IV Integrated Strategies 74
9 Design Studies 75
10 Green The Hague 77 10.1 Green in The Hague 79 10.2 Non-green Areas 80 10.3 Green Areas 86 10.4 Young Green Areas 87 10.5 Green Inner Courts 88 10.6 Green Roofs 89 10.7 Phasing 90 10.8 Actors 90 10.9 Policy 91
11 Dense The Hague 95 11.1 Dense The Hague 96 11.2 De-densification Areas 96 11.3 Renovation Areas 97 11.4 Densification 98 11.5 New Extentions 99 11.6 City Center 99 11.7 Development Focus Zones 99 11.8 City-heating Networks 99 11.9 Phasing 100 11.10 Actors 100 11.11 Policy 101
14 Contents
12 Healthy Ageing in The Hague 105 12.1 Housing of the Elderly 105 12.2 Elderly in The Hague 106 12.3 Renovating Dwellings 106 12.4 Education 108 12.5 Phasing 108 12.6 Actors 109 12.7 Policy 109
13 The Hague 2040+ 113
14 Conclusion 117 14.1 Part 1 - Problem Analysis 105 14.2 Part 2 - Mitigation and Adaptation Strategies 106 14.3 Part 3 - The Case of The Hague 106 14.4 Part 4 - Integrated Strategy 108
15 Follow-up 123
16 Reflection 125
Literature 127
Acknowledgements 133
Appendices 135 A1 - Neighbourhoods and Boroughs of The Hague 136 A2 - The Hague Vulnerability Assessment 138
15 I Problem Analysis
16 1 Introduction
Urban heat islands and climate change form a major challenge for Dutch cities and will have consequences for the way we live and use our cities (Bhattacharya, 2003). The urgency to handle is picked up by the government and municipalities but not always in an effective way (Salcedo Rahola et al., 2009a).
1.1 Urban Heat Islands Salcedo defines the urban heat island as the effect of cities accumulating heat and consequently being warmer than their surroundings (Salcedo Rahola, Van Oppen, & Mulder, 2009b). Klok named two methods to describe heat islands: first, the difference in air temperature above the city and the rural surroundings; atmospheric urban heat. And second, the difference in surface temperature between the city surfaces and the city surrounding areas; surface heat islands (Klok, Schaminee, Duyzer, & Steenveld, 2012). Throughout this thesis I focus on surface heat islands, because for this method necessary data are available.
Recent study by TNO reveals that The Hague has an average surface heat island of almost 9ᵒC, whilst the average for Dutch cities is 2,9ᵒC. Urban heat islands lead to a higher use of resources and an increase in air pollution. Especially during the summer urban heat islands become more of concern, because of the higher overall temperatures (Rosenzweig et al., 2005).
Figure 1.1; The diurnal difference between surface heat islands (SHI) and atmos- pheric heat islands- m(AHI). Both types are present during day and night but the influx of solar radiation makes the SHI stronger. Image by EPA, 2008.
17 1.2.1 Main causes Urban heat islands are generally caused by urbanization. Buildings, roads and paved surfaces turn solar radiation into heat, which is slowly released back in the streets when it cools down keeping urban areas warmer than rural areas (Jusuf, Wong, Hagen, Anggoro, & Hong, 2007). Apart from storing heat, buildings disrupt streams of wind which have a natural cooling effect (Döpp & Albers, 2008). Additionally Salcedo describes that lack of vegetation limits evaporation, the process by which heat is subtracted from the surrounding. Urban heat is further enhanced by anthropogenic heat and air pollution caused by power stations, transport and industrial processes (Rosenzweig et al., 2005).
1.2.2 Consequences Higher temperatures in cities have a negative effect on human health. Sustaining heat causes heat stress leading to tiredness, lower productivity and aggression. Especially babies, elderly and people suffering from chronic diseases are vulnerable during warmer periods (Kleerekoper, 2009). Studies by Robine concluded that the average mortality in Europe during the hot summer of 2003 was increased by 70.000 deaths, making global warming a serious health threat for an aging Europe (Robine et al., 2008). Finally, ecological cycles change due to increased temperatures and higher energy demands put more pressure on the environment.
1.2 Climate Change As said before urban heat becomes more pressing during the summer when overall temperatures are higher. Climate scenarios by the Royal Dutch Meteorological Institute (KNMI) and the Intergovernmental Panel on Climate Change (IPCC) show that the average global temperature will increase. According to IPCC the average rise will be between 1.1 to 6.4ᵒC this century; leading to even higher temperatures in cities (AR4, 2007). Döpp notes that models of climate change are different for cities than for countries nationwide; he predicts that temperature rise in cities will be even higher (Döpp & Albers, 2008).
Warmer weather will increase the risk of extreme weather, resulting in more heatwaves (IPCC, 2007). The impact on cities will be considerable, since urban areas suffer the most from heatwaves. Salcedo states that during heatwaves due to higher influx of solar radiation more heat will be stored in cities (Salcedo Rahola et al.,
18 Introduction
2009a). During the heatwave in the summer of 2003 temperatures increased to 6ᵒC above average (Rebetez, Dupont, & Giroud, 2008), which had severe effects. For The Netherlands Huynen predicts an increase in heat related deaths ranging from 0,5% to 2,5% (Huynen, Martens, Schram, & Weijenberg, 2001).
1.3 General Adaptation Strategies Salcedo et al. (2009) have divided options adapting to urban heat into three groups: (1) reducing solar exposed surface, (2) reducing absorption of heat, and (3) increase the natural cooling. These actions can be taken on three levels: buildings, neighbourhood and city. Actions taken on building level mostly affect the indoor climate and traditionally include: natural ventilation, heat pumps, absorption heat pumps, green roofs, cool roofs, insulation and sun shading. Furthermore orientation of windows on the south adds to passive heating in winters and prevention of heating during the summer. Climate Proof Cities (CPC) concluded that fitting of movable sun screening and extra ventilation is highly effective and can almost completely prevent the heating up of modern well insulated houses. They also conclude that the effect of light- or green roofs on street level is not clear. Lastly they conclude that façade materials with high albedo values are undesirable because of reflected radiation (“Climate Proof Cities,” 2015). Therefore the use of high albedo materials is no further discussed in this thesis.
(1) Shading (2) Reflection (3) Ventilation (4) Evaporation
1. Knowledge for Climate was a Dutch research program in the field of climate change and adaptation. The program ran from 2007 till end December 2014. Partners in the foundation, that ran the program, were Wageningen UR, Utrecht University, the VU University Amsterdam, KNMI, TNO and Deltares (Kennis Voor Klimaat 2015).
19 Adaptation actions taken at neighbourhood- or city level mainly affect the outdoor climte and traditionally include: vegetation, pavements, water applications, neighbourhood structure and city structure. CPC adds that a structure of green spaces in the city has a positive effect on the city temperature. Additionally the placement of trees in streets have a more positive effect on thermal comfort on street level than green facades and roofs because of the shading trees provide. Furthermore, people feel more comfortable in streets with green elements preferably on different levels with a height/width-ratio of 0,5 for optimal ventilation and shading. Lastly water can be used for cooling, provided it is being vaporized by for instance a fountain. However, large bodies of water will like buildings store heat and thus contribute to urban heat.
1.4 Urgency for Climate Adaptation in The Hague Recent events show that heat can be a major problem for Western European cities and European cities seem less prepared for this than Asian or African cities (Bhattacharya, 2003). Dutch policy on climate adaptation has always focused on water defence management and not on heat (Döpp & Albers, 2008). It took until 2007, after the 2003 and 2006 heatwaves for the Dutch Ministry for Health, Wellbeing and Sport to come up with the National Heat Plan offering a range of measures focusing on preparation for and what to do during sustaining heat. However, this policy does until today not offer any measures to prevent urban heating in the first place. The absence of adequate policy on urban heating in the Netherlands is according to Van Ierland (2006) caused by the administrative complexity of working with different authorities, actors, stakeholders and responsibilities. In order to develop effective climate adaptation strategies CPC strongly advices an integrated approach (“Climate Proof Cities,” 2015).
On national and international level, attention for urban heat is increasing; Rotterdam has launched the Rotterdam Climate Initiative, a joint program the Port of Rotterdam, the City of Rotterdam and other organizations. Internationally many cities including London (Greater London Authority, 2011) and New York (Bloomberg, 2013) have developed comprehensive climate adaptation strategies in which flooding, drought and heat are treated side by side. In the Memorandum Towards a Sustainable The Hague (2009) the city of The Hague describes the ambition to develop public space in a sustainable, versatile and integrated way. However, there is no mentioning of climate adaption strategies related to urban heat. Also in the more recent Climate Plan (2011) the city does not mention heat as a climate problem.
20 Introduction
In 2011 in an answer to questions raised in the city council relating to the climate adaptation strategies of The Hague, the municipality said to be waiting for the outcome of the Knowledge for Climate-program1 (Gemeente Den Haag, 2011). The municipality’s indifference towards urban heat until now has made that some distressed citizens have launched the website hitte-eilanden.nl providing information on urban heat and what measures citizens can take (van Veen & van Eeden, 2014).
With the completion of the Knowledge for Climate-program and the need for The Hague to develop an effective climate adaptation-program in mind, this thesis will look into The Hague’s climate adaptation policy and will focus on how urban heat mitigation and adaptation strategies can be integrated in the spatial planning of the city of The Hague.
1.5 Objective of the Research This study aims to design an integrated approach to develop measures to mitigate urban heat islands of The Hague. In order to design this strategy I will reflect on the current climate ambitions and policies of The Hague and combine them with spatial strategies for urban heat mitigation. The strategy developed in this research will give the municipality of The Hague insight on how to deal with climate change and urban heat in particular in her spatial planning.
1.6 Research Question
“How to further improve climate adaptation and mitigation strategies of The Hague with regard to urban heat with the objective to integrate them into the spatial planning of the city of The Hague?”
1.7 Outcome The outcome of this research is a set of recommendations for strategic interventions on urban scale that will contribute to mitigate urban heat in the city of The Hague.
1 From 2007 till the end of 2014 the Knowledge for Climate was a research program focusing on climate- change and adaptation. Within the program several sub-projects were carried out, like Climate Proof Cities. The program was led by Wageningen UR, Utrecht University, VU University Amsterdam, KNMI, TNO and Deltares (“Kennis voor klimaat,” 2015).
21 22 2 Research Design
2.1 Sub-research Questions
In this research the following sub-research questions will be answered:
1. What general effects does urban heat have on The Hague and its population? 2. What climate adaptation strategies are recommended from other research programs? 3. What can we learn from urban practices regarding climate adaptation on an international scale? 4. Which locations in The Hague can be indicated as vulnerable for urban heat? 5. What ambitions and policies on climate adaptation and urban heat in particular are currently executed in The Hague? 6. How can existing strategies be enriched with climate adaptation measures in The Hague? 7. What policy changes are needed to support these proposed measures in The Hague?
These questions will be answered in four parts.
2.2 Part 1 - Problem Analysis This part of the research looks into heat problems in The Hague, to determine the effect on the city and its population by literature study (question 1).
2.3 Part 2 - Mitagtion and Adaptation Strategies The second part of the research looks into the measures and strategies which can be used to mitigate urban heat. The conclusions of the Climate Proof Cities-program are evaluated and the necessity for an integrated strategy is discussed (question 2). Simultaneously the climate adaptation strategies of other cities is analysed (question 3).
In order to get to comparable results, a methodology has been developed which evaluates strategies in three steps:
Step 1: exploring the context. In this step the city characteristics are determined.
Outcome: basic demographics, geomorphological information and surface temperature in the studied city in maps.
23 Step 2: reporting on the existing ambitions, policy and actions.
Outcome: an overview of the cities ambitions towards climate adaptations and related policy and actions.
Step 3: defining background information on phasing, actors, locations and scales.
Outcome: written document containing background information on how measures and policy can be executed.
General outcome:
◊ recommendations from research programs on climate adaptaion on climate adaptation strategies; ◊ insight in the adaptation strategies used by Singapore, Stuttgart and Amsterdam.
Definition of terminology:
City characteristics — Basic demographics and geomorphological information on the studied city.
Ambitions — The desired goals to be achieved.
Policy — Political instrument for realizing ambitions.
Actions — The related execution of the ambition in measures.
Phasing — The period of time in which an action gets implemented.
Actors — The parties involved, the participants or those who will experience the consequences of the action.
Locations — Places where the action are aimed at.
Scales — The level (building, neighborhood or city) on which the actions are implemented.
24 Research Design
2.4 Part 3 - The Case of The Hague The third part focusses on the case study in The Hague. In this context an assessment will be made of The Hague’s vulnerability to urban heat, by using satellite data and open source population data (question 4). At the same time The Hague’s policy on climate adaptation in relation to urban heat will be assessed (question 5).
General outcome:
◊ vulnerability map of The Hague indicating locations now vulnerable for heat; ◊ potential map of the municipality’s climate ambitions for The Hague 2040.
2.5 Part 4 - Integrated Strategy In the final part of this research three design studies will be presented containing proposals for The Hague concerning urban heat risk factors as determined in part 3. The goal of the studies is to apply heat mitigating measures on The Hague in relation to the potential maps made in part 2 and the heat presented made in part 3. Resulting in a design presenting options aimed at solving or mitigating The Hague’s current heat problems, by combining the policies on climate adaptation the city has with suitable adaptation strategies (questions 6 & 7).
General outcome:
◊ advice on which measures are in accordance to the policy and can be implemented; ◊ advice on where policies need to be changed to suit necessary measures; ◊ integral design for a heat proof The Hague by 2040.
25 I Problem Analysis
26 3 The Hague and Urban Heat
This chapter looks into the effects and consequences of urban heat on The Hague. According to the Dutch Central Bureau for Statistics (CBS) the population The Hague will grow to 570.000 inhabitants (14% increase) by 2040. By then 19% of the population will be older than 65 (Centraal Bureau voor de Statistiek, 2013). Given the warmer climate scenario’s and the fact that urban heat is highly related to lay-out and growth of the city (“Climate Proof Cities,” 2015) in combination with the fact that especially elderly people are vulnerable for heat (Van der Hoeven & Wandl, 2013), underlines the urgency of this problem.
3.1 Urban Heat Island The Hague The forming of urban heat islands is mainly determined by population density and city-/ neighbourhood configuration and not so much by city size and population, as was often assumed (“Climate Proof Cities,” 2015). Research by TNO reveals that surface heat islands occur in many Dutch cities as can be seen in figure 3.1 (Hove et al., 2011). It is clear that The Hague preforms poorly with an average surface heat island of 8,6ᵒC during daytime. For this high score there are several explanations; first of all The Hague has a very high population density; 6.240 inhabitants per km2 compared to 4.908 in Amsterdam, the second densest city in The Netherlands (CBS, 2013). On top of that The Hague has the highest built-up/ paved area ratio (0,49) of the Netherlands. These areas warm faster than natural, water-permeable surfaces. This is shown in figure 3.2. Red dots indicate heat in dense parts of the city and industrial areas. The research by TNO also shows that cities which are built on sand (for example Amersfoort, Tilburg, Etten-Leur) are warmer during daytime. Dry surfaces, like sand, heat up faster in comparison to wet surfaces like peat and clay.
Figure 3.1; The average surface heat island effect (SHI) for the 73 biggest cities in The Netherlands, increases during daytime (left) and during night-time (right) with the intensification of paved- / built-up areas (Hove et al., 2011).
27 The Hague is built on clay, but parts are situated in the dunes. Grid cells used in the research by TNO to determine surface heat can be marked as urban, but as they can overlap with the dunes, the city appears warmer than it actually is (Klok et al., 2012).
The surface heat at night in The Hague is below average. This can be explained by the fact that dunes cool down easily during the night. The Hague’s location as a coastal town is another reason for the lower scores during night-time, since the sea has a cooling effect on the city during the night.
3.2 City Characteristics Influencing the Heat Island of The Hague As discussed in the previous paragraph density, built up surface area and the city’s geographical location are major influences for the forming of urban heat islands. Besides from these aspects there are other city characteristics influencing the forming of heat islands. Identifying factors causing cities to warm up makes it possible to undertake effective actions to mitigate urban heat. Needed actions will differ throughout the city, depending on the variation of factors causing vulnerability to heat. This will be explained further in chapter 7. This paragraph focusses on the city characteristics influencing urban heat.
Urban development implies that natural, open, water permeable surfaces and green is replaced with paved and built up areas like streets, squares, parking lots and buildings. In a natural environment green areas and trees provide shade and evaporation of water lowering surface- and air temperature. The high percentage of paved areas and buildings in cities disturb this process of evaporation and thus natural cooling. Moreover, a lack of shade in streets exposes paved surfaces and facades to direct solar radiation, increasing the heat in the city.
Urban heat is not caused by the absence of green structure. The reflectivity, emissivity and heat absorption of building materials and pavement also have a big influence on surface temperatures of streets and facades. Applied building materials often have low albedo values (reflection index), meaning they reflect less sunlight, resulting in higher surface- and air temperature. Lower reflection also leads to more stored heat in these materials. When the city cools down, the high emissivity coefficient of these materials means the heat is radiated back to its surroundings, keeping cities warm at night. All these characteristics make that cities absorb twice as much heat as the rural area (EPA (Environment Protection Agency), 2008a).
28 The Hague and Urban Heat
The way the city is built up also plays a major part in urban heating. The sky view factor determines the percentage of sky that is visible from a given place. A high percentage, in a field for instance, means that the sun’s short wave radiation is reflected back towards the sky more easily. In densely built-up areas with low sky view factors this radiation bounces back and forth between buildings. As a consequence, these areas cool down much slower than open areas resulting in higher temperatures (Lenzholzer, 2013).
Heat is not only caused by the solar radiation. Anthropogenic activities like traffic, cooling of buildings and heat produced in production processes also adds to the urban heat. Though the total contribution of added heat is hard to quantify industrial areas and denser city parts become directly visible in satellite images of surface heat (EPA (Environment Protection Agency), 2008b).
Finally factors like geographical location of a city, the orientation of the buildings towards the dominant direction of the wind all have an influence on the heat in a city (Hove et al., 2011)
Figure 3.2; Surface temperature of the Westland on June 13th, 2014, at 12:39 P.M. WET. The temperatures in The Hague are higher than in the surrounding rural area and the greenhouses. Temperature in Kelvin Data from Landsat 8, map created by author in BEAM Visat 5.
29 II Mitgation and Adaptation Strategies
30 4 Integrated Strategies
4.1 Meetings with The Hague and Rotterdam The municipality of The Hague has recently started looking into her climate adaptation strategies, including urban heat. In the scope of this development a meeting took place on the 2nd of February, 2015 between Niels Al and Arno Lammers (both planners at the city of The Hague), Frank van der Hoeven (TU Delft), Alexander Wandl (TU Delft) and Daphne van Dooren (fellow student) and myself. The meeting focussed on the city’s climate adaptation strategy, including urban heat. The main conclusion was that becoming energy neutral is a major incentive for the city and urban heat will probably follow in these projects.
From the meeting was concluded that mitigation of urban heat should work on five levels. First of all people have to take care of each other on personal level during periods of heat. Secondly, citizens should be well informed on predicted weather and the consequences. Third are minor adaptions to buildings, e.g. installing sun shading and developing climate proof gardens. As fourth, larger technical changes can be made, e.g. installing triple glassed windows, insulation, heat pumps, solar panels or even (re)building energy neutral houses. Lastly the organization of the public space should contribute to safe and healthy places. This is the main domain of the municipality.
On February 11th another meeting took place in Rotterdam with Roland van der Heijden of the municipality of Rotterdam on the same topic. He is aiming to make a business case out of climate adaptation projects. This is done by looking for connections between different themes and thus going from a sectoral to an integral approach. For instance, one can look at the influence of ‘walkability’ on urban heat and find a suitable strategy to improve the cities walkability and in the meantime mitigating urban heat.
As part of this integral approach Rotterdam has developed The Energy Atlas in which they keep track of energy deficiencies and surpluses related to demographic- and geographic data, urban planning and the livability of the city. Mitigation of heat can as such be made part of other processes on improving the livability, intercepting changing energy demand or improving the city’s economy.
31 It can be concluded that both cities are working on setting or meeting their climate goals. Rotterdam is way further than The Hague, but that might put The Hague in a favourable position since they have the opportunity to learn from Rotterdam. Both cities agree that in order to run a program to mitigate urban heat, actions have to be of an integral character; going from sectoral policy to integral strategies.
4.1 International Panel for Climate Change There are two types of strategies for dealing with urban heat and climate adaptation. On the one hand mitigation strategies can lessen the causes of climate change and higher temperatures by the reduction of greenhouse gasses, increasing energy efficiency and increased use of sustainable materials. On the other hand adaptation strategies are used on local level to adapt to the regional effects of climate change (Heuvel, 2009). Strategies can operate on different levels, from international or European level to, national, regional and local.
On choosing measures to be taken, it is good to consider which possibilities are already present and whether adaptation- or mitigation measures can be integrated in broader development strategies. The IPCC, established by the United Nations Environmental Programme (UNEP) and forming a worldwide leading institute for the assessment of climate change, has categorized the relation between mitigation and adaptation in four groups (AR4, 2007):
1. adaptation measures which also have an impact for mitigation; 2. mitigation measures which also have an impact on adaption; 3. decisions which contain a consideration or synergy between mitigation and adaptation; 4. processes which have effect on adaptation as well as on mitigation.
According to the IPCC the synergy between mitigation and adaptation can be significant in urban areas. When developing a climate programme it is important to consider mitigation and adaptation simultaneously. Lack of knowledge on certain topics or lack of interest for institutional and organizational capabilities can diminish synergy (Drunen & Lasage, 2007).
32 Integrated Strategies
Additionally, when developing the adaptation strategy a balance has to be found between emergency planning (for during the disaster/ heat wave) and strategic planning (for long term changes). Strategies differ from city to city and also within cities. Commercial and industrial areas profit most from adaptation measures that offer relief from high temperatures. Residential areas are best helped with measures mitigating heat in favour to maintain livability during day and night.
33 34 5 Research Programs
Knowledge for Climate was a Dutch research program focussing on climate- change and adaptation which ran from 2007 till the end of 2014. Part of this project was the research program Climate Proof Cities (CPC) which yielded new insights on making Dutch cities climate proof with a focus on urban heat and flooding. The conclusions of the research are categorized under vulnerability, measures and governance and are acknowledged as the most comprehensive and up to date advice for policy makers in the Netherlands. The most interesting conclusions are discussed below and applied throughout this thesis.
5.1 Vulnerability ◊ The following conclusions from CPC are new or important enough to repeat regarding the vulnerability and exposure to heat stress in the built environment: ◊ the ratio between built up- /paved area and green structure are the main factors for heat islands. The average building height has an influence on surface temperature during the day and urban heat island intensity during the night. The ratio for Urban Canyon shows an optimum at height/width = 1; ◊ population density and city-/ neighbourhood configuration are more decisive for urban heat islands than number of inhabitants and geographical location; ◊ urban green cools the environment by shadow and evaporation; low evaporation is caused by both paved surfaces and the lack of water for evaporation which causes higher temperatures in cities; ◊ insulation of buildings without paying attention to protection against incoming solar radiation leads to more heat disturbance during summers. In addition, apartments heat up faster than row-housing and free standing houses. ◊ thermal comfort during daytime is mainly determined by the movement of air between different places; at night-time the temperature differences are more decisive; ◊ an area’s vulnerability for heat is influenced by neighbourhood- and building characteristics and dispersion of sensitive people and objects.
35 5.2 Measures The following measures proposed by CPC are new or important enough to repeat:
◊ the city’s green structure has a positive effect on the city temperature. Street trees are more effective for increasing thermal comfort than green- facades and roofs because they provide shading. Parks are on average 2ᵒC cooler than surrounding urban areas. Furthermore, people feel more comfortable in streets with different kinds of green. Streets with height/width-ratio of 0,5 are optimal for ventilation and shading2; ◊ the effect of light- and green roofs on the climate on street level is not clear. Green roofs with ‘pinched drainage’ have a small effect on indoor- and outdoor temperatures as well as water retention. High albedo values in facades are undesirable because of reflected radiation; ◊ orientation of windows on the south adds to passive heating in winters. The addition of movable sun screening can prevent heating of modern well insulated houses. Natural ventilation, when outdoor temperatures are lower than the indoors can prevent the need to run air-conditioning; ◊ adaptation strategies have a positive effect on other policy issues like mitigation and biodiversity, and/or improving the overall livability in buildings and public space; ◊ difference in micro climate is important for urban planning. Loam and clay seem to accumulate heat, and as a result are cooler during the day and warmer during the night. Sand and peat are warmer during the day, but result in lower surface temperatures during the night; ◊ implementation of measures during the coming decades can take place in phases by linking them to regular maintenance and renovation, reducing costs.
2. The conclusion that the ideal height/with ratio is somewhat short minded, because the orientation of streets plays a more important role than it is given in these conclusions. Streets running in east-west direction pack much more heat during the day, than streets running in north-south direction.
36 Research Programs
5.3 Governance Finally CPC gives a set of recommendations for implementation of climate adaptation strategies on governmental but also societal level.
◊ in order to realize climate adaptation goals in cities a combination of a dedicated (key projects) and a mainstreaming (implementation through regular maintenance) approach is the most promising; ◊ dedicated focus on climate adaptation strategies is crucial for successful implementation. This is achieved when authorities, civilians and private parties see the climate proof city as a communal goal. It is important to remember that mainstreaming of climate ambitions is more focused on long term and can hardly be enforced; ◊ measures can often be integrated in other policies, this asks for interdisciplinary cooperation. Therefore there is a major role ‘policy matchmakers’ who convince policy makers of the importance of climate adaptation; ◊ municipalities have a major responsibility in climate adaptation; however the success lies in the involvement of all actors. ‘Active citizenship’ can be enhanced by making an interactive inventory of all that happens in the city when developing vision and policy; ◊ uncertainty about future values, phasing period and indirect benefits creates hesitation with policy makers to execute ‘Tax Increment Finance’-methods for climate adaptation financing.
To conclude; Climate Proof Cities points towards an integrated approach for successful climate adaptation which asks for policy makers to combine their individual strategies for urban design, planning, infrastructure and housing into a comprehensive plan to climate proof cities and find suitable ways to finance the needed adaptation. However, the role of citizens and private parties should not be neglected. Housing corporations have to become more aware of need for climate adaptation and proactive citizens may be obstructed by governmental thinking of municipalities.
37 III Design guidelines
38 6 Comparative Analysis
Internationally there are many cities working on climate adaptation programs. For this thesis a case will be made for Singapore, Stuttgart and Amsterdam. The cities are assed on city characteristics, urban heat and their climate adaptation strategies. Goal is to reveal which ambitions, policy and relating actions the cities’ have regarding urban heat and see if these might fit for the case of The Hague.
6.1.1 Methodology - Remote Sensing For this analysis satellite images of the Landsat 8 have been used. Landsat is a joint initiative between U.S. Geological Survey (USGS) and NASA and has been providing moderate-resolution land remote sensing data for over four decades which is used for government, commercial, industrial, civilian, military, and educational communities. The Landsat 8 satellite, running since 30th May 2013, images the entire earth every 16 days in an 8 day offset from the Landsat 7 (USGS, 2013).
6.1.2 Normalized Difference Vegetation Index (NDVI) The sensing data retrieved by Landsat 8 is used to analyse the green structure in and around the cities; this is done since green structure plays a major role in keeping cities cool. The NDVI is calculated by the reflection of visible and near infrared light of vegetation. The calculation of the NDVI always results in values between minus one (-1) and plus one (+1), where zero means no vegetation and values over +0,8 mean maximum vegetation (Earth Observatory, 2002).
6.1.3 Land Surface Temperature (LST) In this research the land surface temperature (LST) is used as indicator for heat in the city. To calculate the LST the thermal bands 10 and 11 of the Landsat 8 satellite are used. Hereby finding data without clouds is more important than retrieving data from the warmest day of the year, because urban heat island effect is visible all year long. Therefore the images used in this analysis do not represent maximum surface temperatures of specific places in the city, but they show warmer areas in the city where heat stress might develop into a problem during heatwaves. Like the NDVI images these maps have been made using BEAM Visat v5. The skills to process data into usable imagery has been obtained during a self-organized workshop given by Dr.ir. Frank van der Hoeven on January 26th, 2015.
39 6.2.1 Singapore Singapore is the biggest city/ country in this comparison and runs a comprehensive strategy to increase the amount of green surface to among other goals mitigate urban heat despite the extreme climate. The hot tropical rainforest climate shows no distinctive seasons with uniform air pressure and temperature between 22 and 35˚C, high humidity and an abundance of rainfall. As can be seen in figure 6.1, the city centre is located in the most southern point of the island and the city spreads out towards the north in urban and rural areas. The western part of the island is used by the world’s second biggest harbour, and in the east a major international airport is located. Despite the high density, the island is covered with over 50% green areas, networks of parks, nature reserves, park connectors, nature ways, tree-lined roads and other areas, which enhance the sense of green space in the city (NParks, 2015). This has awarded Singapore with a fourth place in the Environmental Performance Index 2014 (Hsu et al., 2014).
6.2.2 Urban Heat Island The land surface temperature of Singapore in figure 6.2 shows the different temperatures between the ‘rural,’ the ‘urban’ and the harbour areas. According to two mobile surveys conducted by the National University of Singapore, the maximum air temperature difference between well planted areas and the down town area (CBD) is 4,01˚C. Historical analysis of temperatures in Singapore proofs the relation between increasing land-use and higher city temperatures. Therefore the city invests in increasing the amount of green surfaces in Singapore as well as minimizing the release of anthropogenic heat to mitigate the urban heat at micro level (Wong, 2004). 6.2.3 Policy – City in a Garden In the 1960’s the Singapore government set to transforming Singapore into a garden city. The goal was to create a city-state situated in a garden environment consisting of parks, gardens and open spaces linked to each other by tree-lined roads and park connectors for cyclists. This was not only done to benefit the inhabitants. Mr. Lee Kuan Yew, then Prime Minister believed that the garden city would also attract foreign investment. The execution of this policy was done by the National Parks Bond (NParks) which until today oversees all development and maintenance of green in Singapore. The result of the program is that Singapore is for 56% covered with vegetation divided over four nature reserves and more than 300 parks spread over the island connected to each other by streets with extensive road side greenery, which form the bases of the structure of the garden city (NParks, 2015).
40 Comparative Analysis - Singapore
Figure 6.1; The expanding urban areas of Singapore slowly push out the rural areas. The nature reserve Mount Faber (forest) has been sur- Forest Rural areas rounded by the city and the urban areas. In the west
Airport and the east the harbour
Urban areas and the airports form major Harbour impervious areas of which City the result can be seen in the land surface tempera- Gardens by the Bay CBD ture map. Map by author. 0 1 2 5 10 km
Figure 6.2; The land surface temper- ature of Singapore on No- vember 14th, 2014 shows the temperature difference between the ‘rural,’ the ‘urban’ and the harbour areas. The black-blue spots in the image are clouds. Temperatures in Kelvin. Data from Landsat 8, map created by author in BEAM Visat 5.
0 1 2 5 10 km
41 6.2.4 Ambitions and Actions Today Singapore’s ambitions have changed slightly; the city now plans to become a ‘city in a garden,’ as relieve for the high density, urban-living (MND Singapore, 2008). Therefore the city plans to build new (botanical) gardens, revitalizes old parks and re-designs streets to offer more road-side greenery. The goals of these actions are to increase biodiversity on the island and create more pervious, shaded areas where people can recreate. Some key projects are:
◊ Streetscape Greenery Master Plan is a project to increase the amount of green spaces along roads and plant these with larger varieties of species. ◊ Park connectors network are newly built green corridors connecting major parks and nature sites by developing otherwise fallow land. ◊ Community in Bloom and Adopt a Park are projects to involve Singaporeans in participating in greening and maintaining their natural surroundings. ◊ Gardens by the Bay is a very expensive (1.035 billion dollar (Gardens by the Bay, 2014)) park development in Singapore’s new downtown area and brings all plant species available on the island together as an attraction in one botanical garden of over 101 hectares (MND Singapore, 2008). ◊ Skyrise Greenery seeks opportunities to develop facades and roofs into green areas to add to the islands green urban environment. This project makes it possible to increase the amount of greenery even in very dense built up and populated areas (Nparks, 2012).
6.2.5 Conclusion The financial resources Singapore has to execute these strategies don’t compare to The Hague’s financial freedom. However, the city uses green as an investment to attract foreign capital, which can also be introduced in The Hague. Next to that the strategies for green roofs and facades and Adopt a Park create opportunities for participatory projects the municipality can set up with inhabitants and professional parties like housing corporations and insurance-/ retirement agencies.
42 Comparative Analysis - Singapore
Figure 6.3; The NDVI on November 11th, 2014 shows Mount Faber and the rural areas in the west as green lungs of the island. In the built up areas the network of parks and park ways are visible. Data from Landsat 8, map created by author in BEAM Visat 5.
0 1 2 5 10 km
43 6.3.1 Stuttgart Slightly bigger than The Hague, Stuttgart was the first German city that elected a ‘green’ major, Fritz Kuhn, Grünen (Der Spiegel, 2012). But before that, the city already had a lot of experience with environmental planning by officials and city planners (Hebbert & Webb, 2011). Stuttgart’s location in a valley basin, mild climate, low winds and surrounding industrial activities has made the city vulnerable for poor air quality since the ‘70’s. The development of the hill sides has made the situation worse because air movement is now hindered moving through the city, increasing the urban island effect (Kazmierczak & Carter, 2010).
6.3.2 Urban Heat Island Already in 1978 the city of Stuttgart possessed fine grained maps of the urban heat island indicating the existence of a heat island (Hebbert & Webb, 2011). Today the average heat island for Stuttgart is between 1 and 2˚C. Research by Kazmierczak and Carter has turned out that by 2100 57% of the Greater Stuttgart region could have more than 30 days of heat stress with a 2 degree temperature increase, for the denser city this could even over 60 days per year. This means that by 2100 a significant higher number of people will be exposed to heat stress (Kazmierczak & Carter, 2010).
6.3.3 Policy – Natural Ventilation As stated, Stuttgart has already for a long time payed attention to climatically-aware design. The design objective for the first suburbs in 1868 was to create ‘unhindered access of light and air’ to all houses. With the city extension plan of 1901 a technical appendix was delivered on the natural patterns of wind movement in the city valleys. Maintaining these natural ventilators was the goal for many new developments, even for the planning policy of the city’s post-war 1948 General Binding Site Plan.
Today, the municipality of Stuttgart runs an urban climatology and environmental pollution unit of ten scientists. Their work provides recommendations for city planning; therefore they have developed the ‘klimafibel.’ In this climate atlas among many others, the following principles are formulated regarding the urban climate; facilitating air exchange in the city and enhancing cool air inflow from the hills, no spatial development is allowed that would obstruct air-flow in key strategic areas, felling of trees over a certain size is banned, and green roofs, green facades and other solutions are promoted in densely developed areas (Reuter & Kapp, 2012; Hebbert & Webb, 2011).
44 Comparative Analysis - Stuttgart
Figure 6.4; The geological location and industries make Stuttgart vulnerable for urban Urban areas heat. The development of the hill sides hinders the Industry natural airflow towards City the city from the terrain. Terrain The factories of Daimler, Porsche and Bosch, as well Terrain as Hewlett-Packard and Urban areas IBM put pressure on the air quality. Map by author. Airport 0 1 2.5 5 km
Figure 6.5; The land surface temperature of Stuttgart greater region on July 19th, 2014 shows the temperature difference between the ‘city,’ the ‘industrial’ and the forest areas. The predominant wind direction from the south-west brings cool air from the into the city. Policy is enstated to prevent terrain and built-up areas to obstruct natural airflow. Data from Landsat 8, map created by author in BEAM 0 1 2,5 5 km Visat 5.
45 6.3.4 Ambitions and Actions In the municipal planning of Stuttgart the maintenance of areas for cold air production, fresh air corridors and saving inner city green is a major task. Some key projects to mitigate urban heat in Stuttgart are:
◊ The Hillside Development Outline Plan helps to ensure the creation and maintenance of green and open spaces in the hillside areas. The goal is to safeguard local air exchange by providing guidelines on optimal arrangement of buildings including restraints on excessive height; green corridors that act as ventilation zones; and the alignment of parks and streets to take advantage of the airflow. ◊ Fresh Air Corridors in the form of meadow and stream valleys provide natural green belts and represent pathways for natural ventilation. Therefore these structures are kept free of buildings, ensuring supply of fresh air and reducing thermal stress. ◊ Roof greening is an aspect of Stuttgart’s long-term maintenance and recovery plan for green spaces. Apart from green corridors, green networks through built- up area and green remediation areas, façade greening and green roofs play a role in the preservation and acquisition of green space in the city. ◊ Greened-over Urban Railway Tracks are an effective way to increase the amount of impervious surface in the city, though the concrete bedding prevents rain water to deeply infiltrate in the ground. However, the vaporization has a positive effect on the mitigation of urban heat and maintenance costs of the green tracks are lower than traditional ones. ◊ Roadside Greenery in the form of dense planting helps ensuring better air quality in the city. Extra greenery can be implemented by lowering the amount of traffic lanes and/ or making them narrower. Creating extra room not only benefits the green structure, but also cyclists and pedestrians can gain more space. In addition, this measure reduces traffic speeding but at the same time increases traffic flow. Last, street trees are broadly planted to allow for air flow (CENTRAL EUROPE Programme, 2015).
46 Comparative Analysis - Stuttgart
6.3.5 Conclusion Stuttgart’s long history with environmentally aware development poses a couple of interesting strategies which can be adopted by The Hague; the natural air-flow in Stuttgart coming from the plains can in The Hague be achieved by using the coastal wind systems. Therefore fresh air corridors can be arranged in The Hague. Adding green roofs, green tram ways and roadside greenery to the city’s green areas makes it easier to implement strong green structure.
Figure 6.6; The NDVI on July 19th, 2014 of Stuttgart shows in dark green the forest areas on the terrain from which cool air flows into the city. The dark grey along the river Neckar shows the high amount of non-organic surfaces in the industrial parts. Data from Landsat 8, map created by author in BEAM Visat 5.
0 1 2,5 5 km
47 6.4.1 Amsterdam Being the largest city of the Netherlands with major international connections through business, tourism, harbour- and airport activity the city puts great pressure on the environment and her inhabitants. Though, despite the commissioning of the Amsterwarm-research into the cities vulnerability for heat, which was executed by TU Delft in the context of the Climate Proof Cities-program in 2012, the city offers limited interest in the potential for overheating during hot days; most climate adaptation policy and ambitions are related to water retention and becoming energy independent by investing in solar energy (Gemeente Amsterdam, 2015). This chapter will looks into the conclusions brought up in the publication Amsterwarm by Van der Hoeven and Wandl, 2013.
6.4.2 Urban Heat Island Van der Hoeven and Wandl conclude on bases of the land surface temperature during daytime, the air temperature during night-time and the difference between the air temperatures during day and night during the heatwave of July 2006 that the heat island for Amsterdam is significant (Van der Hoeven & Wandl, 2013).
The surface temperature map of Amsterdam in figure 6.8, made for this research, shows a big differentiation in surface temperatures over the municipality. The coolest areas in the municipality are in the Waterland, located to the northern border of Amsterdam and the IJ-lake. The temperature in this area is 8 to 20˚C lower than in the certain parts of the city centre and the harbour.
6.4.3 Vulnerable Groups and Areas The researchers of Amsterwarm describe the following typologies vulnerable to heat; land-use, vulnerable groups and energy in-efficient working places (Van der Hoeven & Wandl, 2013). From their research a couple of indicators for heat vulnerability can be derived for further research. The criteria further used in this research are land surface temperature, NDVI, livability of the neighbourhood, the average energy label and the amount of people over 75 living in the area. Combined these criteria can indicate vulnerable areas; areas with relative high number of elderly and average or low energy labels and also areas with low livability and bad energy labels are vulnerable for heat.
48 Comparative Analysis - Amsterdam
Figure 6.7; The NDVI calculated over the municipality reveals great contrast between the dense city center and the urban extentions in the west and south built according to modern principles. Data from Landsat 8, map created by author in BEAM Visat 5.
0 1 2,5 5 km
Figure 6.8; The land surface temperature of Amsterdam on June 13th, 2014 shows a big differentiation in surface temperatures over the municipality. Waterland situated on the west bank of the IJ-lake is 8 to 20˚C cooler than the city centre and the harbour. Data from Landsat 8, map created by author in BEAM Visat 5.
0 1 2,5 5 km
49 The fraction of paved surfaces has been left out on purpose; as long as enough shadow is provided by trees impervious surfaces will not heat up. Therefore the green structure is more interesting to look at.
6.4.4 Recommendations from Amsterwarm Van der Hoeven and Wandl recommend that the city develops an adaptation strategy which safeguards inhabitants and businesses from the effects of urban heat island during heatwaves. They describe five components of the strategy which can be integrated in other actions, which makes that there is no independent program needed for urban heat. The five components and how they can be used is discussed below:
◊ Trees and green cool their surrounding by providing shading and evaporating water. Areas with low NDVI values can benefit greatly from newly added green. Attention has to be given to underground cables and pipes and the fact that trees need several decades to grow. Municipalities should stimulate to plant green and trees on private terrain; ◊ Green and cool roofs reflect solar radiation or convert it into energy, when solar panels get installed. Green roofs also add to insulation and may retain rain water to vaporize. Especially flat roofs are suitable for these measures; ◊ Cool and lesser paving reflect more solar radiation or can become part of the green structure. When renovating roads choices can be made to use low albedo materials or bring back less traffic lanes; ◊ Surface water in form of fountains, shallow ponds and basins can cool the surrounding by evaporation of water. This measure can be introduced when public space gets re-designed. Attention has to be paid to the depth and flow of the water since large bodies of water can also retain a lot of heat and radiate this to the surrounding during the night; ◊ Energy efficient buildings prevent energy use to cool buildings. This can be done by using heat storage in the ground. This kind of installations can be installed during the construction or renovation of buildings. Also insulation, sun screens, better glassing, and good ventilation help to reduce energy demand (Van der Hoeven & Wandl, 2013).
50 Comparative Analysis - Amsterdam
6.4.5 Conclusion Amsterdam does not offer any strategies to be adopted in The Hague. Though the conclusions from the Amsterwarm-research propose actions the municipality can work with. Apart from that a methodology for determining vulnerable areas is given, which can be used to point out vulnerable areas in The Hague.
51 III The Case of The Hague
52 7 Climate Assessement
Urban heat in The Hague has consequences for the energy consumption, air quality, health, organic life and thermal comfort in city. In this chapter The Hague’s vulnerable areas are determined using the methodology from the Amsterwarm- project by Van der Hoeven and Wandl (2013) discussed in chapter 6.4.2. with the addition of several new criteria brought up the Climate Proof Cities-program (chapter 5). The result of this assessment is mapped in figure 7.1; The Hague’s urban heat vulnerability map.
7.1. Indicating Warm Areas The urban heat island of The Hague has already been described in chapter 3. In the context of this research new land surface temperature maps of The Hague have been made, to find out which surface areas in the city warm up most. The data used for the mapping has been obtained by Landsat 8 satellite and was further processed in BEAM Visat. Figure 7.2 shows data which was received on September 19th, 2014 at 12:39 a.m. (WET), and shows that there are already significant differences in land surface temperatures throughout the city early in the afternoon. From this map 19 neighbourhoods of The Hague have been appointed as possibly vulnerable for urban heat. These 19 neighbourhoods will be assessed on the other vulnerability factors and physical conditions in chapter 7.2.
7.2 Data Collection As described in chapter 6.4.2 Van der Hoeven and Wandl use in the Amsterwarm- project surface temperature, the amount of people over 75, livability and the average energy label to determine an areas vulnerability to heat. For the completeness, this research adds green structure (determined through the NDVI) and density to the assessment, since these criteria have been found important indicators for heat by Climate Proof Cities.
Areas in this research are described by the neighbourhoods, since these are legislative ranges also used in the policy documents. The term city core refers to the borough centrum (see appendix A1), the term centrum refers to the neighbourhood centrum.
53 The data used to make the maps in figure 7.3 to 7.8 has been gathered from open source databases like the atlas voor de leefomgeving (livability), Tympaan institute (elderly and density), and the energielabel atlas (energy labels). The green structure is determined by calculating the NDVI as is explained in chapter 6.1.1.
From the mapping several interesting conclusions have been stated:
◊ The city core and the industrial areas are warmer than other locations in The Hague (figure 7.2); ◊ Elderly above 75 live mainly outside the city core and thereby avoid the warmer areas (figure 7.3); ◊ In Scheveningen a high concentration of elderly is exposed to heat (figure 7.4); ◊ The warm city core lacks any form of green structure to provide adequate cooling or room for recreation and children to play (figure 7.5); ◊ The lack of green and thus lack of pervious surfaces is probably the biggest cause for areas to become warmer than their surroundings (figure 7.5); ◊ The pattern of low energy labels corresponds to the warmer areas. Only Centrum and Schildersbuurt perform better on energy labels3 (figure 7.6); ◊ The warmer areas do overlap with the increasing density (figure 7.7); ◊ The pattern of livable neighbourhoods seems to follow the heat pattern; lower livability corresponds with higher measured surface temperatures (figure 7.8).
7.3 Vulnerable Neighbourhoods In appendix 2 the 19 neighbourhoods have been rated for their performance per vulnerability criterion. Thereby the scale for the livability and the green structure has been inverted; the more points the worse the situation. The following five residential neighbourhoods can be appointed as most vulnerable for heat in The Hague:
1. Schildersbuurt (29) 2. Transvaalkwartier (30) 3. Rustenburg en Oostbroek (31) 4. Valkenboskwartier (20) 5. Regentessekwartier (21) 6. Scheveningen (7)
3 The relation between energy labels and heat has yet not been adequately studied. Though there are two studies being carried out on the relation; Hotterdam by Van der Hoeven and Wandl and The Visualisation of Urban Heat Island Indoor Temperatures (master thesis) by Iris Theunisse.
54 Climate Assessement
The Hague has two residential areas with a high amount of warehouses and sheds. Lack of green structure and large asphalt roofs make these areas vulnerable. It is advised to consider whether businesses can be moved to locations outside the city, like the bus parking- and service area of HTM, or that in collaboration with the users more shaded areas get created, green roofs installed and more impervious surfaces get realized. These areas are:
1. Groente- en Fruitmarkt (37) 2. Business area Kerktuinen en Zichtenburg, Loosduinen (17)
7.4 Conclusion on Vulnerable Places From the study it can be concluded that especially the city core is very vulnerable for urban heat. The high number of areas with increased surface heat, low liveability, lack of green structure and high densities indicate this. In other areas heat is less likely to form problems because of strong green structure, higher liveability and lower densities. Positive for The Hague is that the elderly currently mainly live in these cooler areas. It has to be seen how this develops until 2040, more on that in chapter 11.
Last, Scheveningen is a special case; the high liveability and low density make this area less vulnerable. However, the lack of green structure combined with a large concentration of elderly, makes Scheveningen an area vulnerable for heat.
55 Figure 7.1; The Hague urban heat vulnerability map
Heat in The Hague Live ability
Poor conditions
Elderly
Concentrations
Elderly homes
6. Residential neighborhoods most vulnerable for heat:
1. Schildersbuurt (29) 2. Transvaalkwartier (30) 3. Rustenburg en Oostbroek (31) 4. Valkenboskwartier (20) 5. Regentessekwartier (21) 6. Scheveningen (7)
Residential areas with low live ability and vulnerable for urban heat.
Industrial areas most 5. vulnerable for heat: 3. A. Groente- en Fruitmarkt (37) B. Kerktuinen en Zichtenburg (17)
4. 1. 2. A.
B. Urban heat mitigating potential Green structure
Green neighborhoods
Young green
0 0,5 1 2,5 5 km
56 Climate Assessement
Figure 7.1; The Hague urban heat vulnerability map
Heat in The Hague Live ability
Poor conditions
Elderly
Concentrations
Elderly homes
6. Residential neighborhoods most vulnerable for heat:
1. Schildersbuurt (29) 2. Transvaalkwartier (30) 3. Rustenburg en Oostbroek (31) 4. Valkenboskwartier (20) 5. Regentessekwartier (21) 6. Scheveningen (7)
Residential areas with low live ability and vulnerable for urban heat.
Industrial areas most 5. vulnerable for heat: 3. A. Groente- en Fruitmarkt (37) B. Kerktuinen en Zichtenburg (17)
4. 1. 2. A.
B. Urban heat mitigating potential Green structure
Green neighborhoods
Young green
0 0,5 1 2,5 5 km
57 Figure 7.2 - Urban heat compared to green structure
Surface temperature at 12:39, September 19, 2014. TValk = 22.1˚C
> 18˚C 22˚C 24˚C 26˚C 28˚C 30˚C
0 0,5 1 2,5 5 km
Figure 7.3 - Relative concentration of elderly over 75
< 2 3 - 5 6 - 10 11 - 15 16 - 20 21 - 25 26 - 50 > 50
Elderly home
0 0,5 1 2,5 5 km
58 Figure 7.4 - Concentration of elderly compared to LST
Elderly outside ‘hot spot’ Low concentration of elderly Normal Medium High
Elderly inside ‘hot spot’ Low concentration Normal Medium High
0 0,5 1 2,5 5 km
Figure 7.4 - NormalizedNormalized Difference Difference Vegetation Vegitation Index Index
No green Hardly green Little green Some green Adundance of green
0 0,5 1 2,5 5 km
59 Figure 7.6 - Energy Labels
A B C D E F G
0 0,5 1 2,5 5 km
Figure 7.7 - DensityDensity per per neighbourhood neighborhood (inh/km (inh/km2) 2)
< 1000 1.000 - 2000 2.000 - 5.000 5.000 - 10.000 10.000 - 15.000 15.000 - 20.000 < 22.000
0 0,5 1 2,5 5 km
60 Climate assessement
Figure 7.2; Warmer areas in the city are the city core, Scheveningen and the industrial areas. Data captured on September 19th, 2014 at 12:39 p.m. (WET) by Landsat 8, map created by author in BEAM Visat 5 and Adobe Illustrator.
Figure 7.3; Elderly in The Hague mainly live in Scheveningen and Loosduinen. The concentrations are highly related to the presence of elderly homes. Data from Tympaan instituut, map by author.
Figure 7.4; The concentrations of elderly hardly overlap with the warmer areas, only in Scheveningen elderly live in warmer areas. Map by author.
Figure 7.5; The NDVI shows the lack of green structure in the city core and Scheveningen. Data from Landsat 8, map created by author in BEAM Visat 5 and Adobe Illustrator.
Figure 7.6; The average energy label in The Hague is E. The low energy labels are most found in warmer areas, with the exception of the Schildersbuurt and Centrum.
Figure 7.7; The Hague’s population is concentrated in the city core. Data from Tympaan instituut, map by author.
Figure 7.8; The livability in The Hague is in general positive. The southern part of the city core scores bad. Data from Atlas Leefomgeving, map by author.
Livability per neighborhood Figure 7.8 - Liveability per neighbouhood
Negative Average Average positive Positive More positive Very positive
0 0,5 1 2,5 5 km
61 62 8 Policy Assessment The Hague 2040
The heat in The Hague has consequences for the energy consumption, air quality, health, organic life, economy and thermal comfort of the city. In order to mitigate the heat related problems the municipality can use policy as legal guidance, communicative guidance, or economical guidance to implement or execute heat mitigating strategies.
In order to give advice on where the city needs to adopt new strategies or policy on this topic, current policy documents relating to urban development are assessed on climate adaptation goals. The goal of this assessment is to find out what the municipality is already working on and where leads can be found for the integration of heat mitigating measures.
The assessment is executed according to the step 2 and 3 as explained in chapter 1.3.
8.1.1 Structuurvisie Den Haag 2020 (Structure Vision The Hague 2020) The cities ambition is to become a “Metropolis at sea.” To insure wellbeing and prosperity, the city wants to invest in living quality, cultural history and green. With an expected population increase to 510.000 till 2020, further investments will be done in accessibility and public space. In order to build more houses in the city centre the municipality plans to increase the built density and to more intensively use the city surface. The Structure Vision affects several policy fields of which spatial planning is the most important. Other fields are employment and culture.
From multiple proposed actions till 2020 these are the most important:
◊ densification of the city (37.500 extra houses); ◊ creation of jobs (40.000); ◊ improvement of (urban) green and connections to rural green (345 ha); ◊ improvement of the public space; ◊ increase water retention in the city to 325 m3/ha of city and seasonal storage.
The document specifies the following inner city locations for expansion; the city core, the coast, along the Vliet, and on the green edges of the city (Lozerlaan). In documents points the Binckhorst, Transvaal and Laakhavens as growth areas in the city core. On regional scale the municipality looks at the Zuidplaspolder and the development of Rotterdam/The Hague Airport.
63 8.1.2 Sociaal economische agenda 2020 (Social Economic Agenda 2020) The Hague has the ambition “to be a pleasant living environment, to form a good start for business, and be a place where tourists and investors like to come.” The document provides a couple of actions in order to achieve this goal. The ones interesting for this research are:
◊ investing in the four so called “krachtwijken” (Transvaal, Schildersbuurt, Stationsbuurt en Zuidwest) in The Hague together with the national government and the housing corporations (2,7 billion euro); ◊ investing in livable neighbourhoods by replanting trees, sustainable urban planning and other environmental projects.
The role of the Social Economic Agenda 2020 is to describe the social criteria which have to be met with the execution of the Structure Vision. Actors with whom the municipality plans to execute this agenda are the housing corporations and the national government. Apart from the ‘krachtwijken’ the Haagse orient and Transvaal are two locations where the city wants to develop attractive living environments to interest new citizens.
8.1.3 Kadernota openbare ruimte 2012 (Memorandum Public Space 2012) The Memorandum Public Space 2012 is the renewed version of the 2004 document. Since 2004 the city has been working on many projects to increase the livability, but after the financial crisis of 2008 the city had to change this strategy. The city’s ambition now is to collaborate with private and third parties to develop public space in order to save costs and reduce nuisance. Locations have been picked in this document to improve the competitive position of The Hague’s on (inter)national scale. The locations are: centre, the international zone and Scheveningen.
8.1.3.1 Haagse bomen (Urban Green in The Hague)
The Urban Green-plan was an appendix of the Memorandum Public Space 2004. The ambition with this document was to ensure that The Hague stays a ‘green’ city. The document steers on maintaining bio-diversity under tree species, to protect them from diseases and warns for the extra pressure that is put on the green structure with the intensification of land-use. The document describes the following actions:
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◊ (re)plating trees in neighbourhoods which not have much green; ◊ on private level people need to green their gardens, for which municipality conditionally offer a fee.
8.1.4 Klimaatplan (Climateplan) The Hague has the ambition to be energy neutral by 2040 and at the same time adapt to the changing climate. In order to become energy neutral the city plans on the one hand to reduce the amount of energy needed and on the other hand to use more sustainable sources for energy.
The municipality expects that by 2040 the energy demand for warming houses built after 1945 will have declined with 60% and for the houses built before 1945 by 30%. After 2020 all houses built have to follow the rules for ‘slim bouwen’ and therefore, according to the municipality, will not need cooling. The energy demand of offices and commercial buildings will remain the same if buildings get improved. In order to warm buildings during winter the municipality focusses on the following actions;
◊ use of cold-heat storage for commercial buildings or groups of dwellings; ◊ heat pumps for single dwellings and HRe boilers; ◊ Large- and small scale city heating networks will be extended for distribution. According to the Climate Plan the city heating networks will not be equipped to cool buildings during the summer; ◊ The municipality expects that the electrical energy demand will stay roughly the same until 2040 thanks to technical improvements; ◊ Besides sustainable housing, passive cooling and sun shades will according to the municipality decrease the need to run air conditioning and thus save energy. The demand for electrical energy will go up 10% of the total demand now to 50% in certain neighbourhoods by 2040. The advantage of this is that the air quality will drastically improve as an impact of the use of electrical cars4; ◊ Policy and target groups related to this proposal are: shareholding, public- private-partnerships, co-exploitation; ◊ Finally, the municipality wants to found a Sustainable Energy Company to subsidize, facilitate, educate, advice and help companies and inhabitants to become less energy dependent.
4 All these expectation seems optimistic given the changing climate, the heat The Hague deals with and the increasing welfare which allows people to buy more goods (air-conditioner, televisions, cars, etc.) that will increase the demand for energy.
65 8.1.5 Woonvisie 2009-2020 (Housing Vision 2009-2020) The ambition coming with the Housing Vision 2009-2020 is to facilitate population growth by building new houses in the city and in the meantime renovating other buildings. The focus lies on renovation of houses built before 1980. The following actions stated in the vision are important for this research:
◊ the demolition of 9000 houses owned by corporations; ◊ building 25.000 new houses; ◊ at least 10.000 improvements of existing buildings; ◊ connecting 12.000 houses to sustainable heat sources; ◊ 30% energy reduction in the social sector.
Locations and related actions for intervention are:
◊ urban transformation of Scheveningen Haven and Bad, Wijnhavenkwartier en Den Haag-nieuw centraal, Binckhorst, Knoop Moerwijk/Laakhavens, Rond de Energiecentrale, A4/Vlietzone and Haga Ziekenhuis; ◊ introducing more green in the neighbourhoods Zuidwest, Mariahoeve, Kijkduin, Lozerlaan, Erasmusveld and Vlietzone.
Actors involved in these projects are mainly the housing corporations.
8.1.6 Energievisie 2012 (Energy Vision 2012) The Energy Vision 2012 proposes the following actions, of which several already have been stated under the Climate Vision:
◊ by 2040 all houses are heated by city heating; ◊ solar boilers in combination with heat pumps, or ◊ HRe-heaters on green gas; ◊ City heating networks are fed with waste energy from glasshouses and heat-cold storage; ◊ Cooling is only necessary for office buildings and can also take place via cooling networks; ◊ Two thirds of the needed electrical energy is generated locally by solar panels, wind energy from sea, and HRe-heaters; ◊ The remaining share of the energy is taken form the national grid but purchased as green energy.
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The municipality uses her energy- and climate policies in different ways to involve actors in execution of these actions; participation in project, obligate connection to heat network and grants.
To help with the energy transition the municipality of The Hague plans to set up the Municipal Sustainable Energy Company, which will develop a broad body of knowledge on specific energy projects; initiate more large scale energy projects, bridge the long term investments and will steer on successful projects.
The actors the municipality can work with in the energy transition are network operators, energy producers, national government, projects developers, real estate owners/ investors, housing corporations, and home owners associations and home owners.
Location; The Hague is located in a zone of useable geothermal heat and aims to use this in combination with the heat networks. This zone stretches from Delft to Scheveningen and promises to be ideal for thermal heat recovery.
8.1.7 Waterplan 2027 (Water Plan 2027) The long term ambition (2027) of The Hague in cooperation with the regional water board Hoogheemraadschap Delfland is to “realize a sustainable, clean, safe and healthy water system, which contributes to an attractive and safe living environment, treated consciously by inhabitants, businesses and visitors of The Hague.” This ambition is subdivided several goals which can be made into policy:
1. sustainable clean and healthy water: the technical state of the water meets the norm; 2. attractive water: the water system contributes to the residential-, working-, and living environment; 3. safe and controlled water: water is well handled and forms no danger for the city; 4. conscious Haags water: citizens are made aware of water in their living environment and know how they can contribute to the system.
Both have concluded that the only way for successful execution of the goals lies in in an integrated approach towards other spatial projects in the city.
67 8.1.8 Nationaal Hitteplan (National Heatplan) The National Heatplan describes how responsibilities are divided during times of emergency. The plan focusses on responsibilities and the importance which has to be given to what to do in periods of extreme weather. These guidelines are developed on national level, but do also apply for The Hague.
8.1.9 Actieplan Luchtkwaliteit Den Haag 2007-2015 (Action Plan Air Quality) In order to increase the air quality in The Hague the program Besluit Luchtkwaliteit started in 2005. This was done because the norms for air pollution were exceeded in regular bases in many streets in The Hague and formed a threat to public health. The Hague’s air quality is for two thirds determined by regional background concentrations and he intense use of cars and frequent congestions in The Hague add to the problem. Local industries and farming, however, hardly influence these concentrations.
An action plan was made to pursue cleaner traffic and a modal shift towards less dependency on cars.
Corresponding actions are:
◊ setting up of ‘milieu zones’ keeping heavy traffic away from vulnerable parts of the city; ◊ replacing old cars by offering grants; ◊ implementing dynamic traffic management and reconfiguring certain intersections in order to improve traffic flow; ◊ re-evaluating parking fees and issuance of parking permits; ◊ investing in bicycle- and public transport infrastructure.
8.1.10 Kadernota duurzaamheid (Memorandum Sustainability)
The purpose of this document is to bring coherence in the existing policy on sustainability in The Hague. The document describes heat, maintenance of flora and fauna, and water as the main challenges in which buildings and the public space play a major role, but doesn’t describe any corresponding policy or actions.
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8.1.11 Nota Haagse Mobiliteit (The Hague’s Mobility Policy)
The Hague describes the ambition of the traffic policy as ‘choose consciously, organize cleverly.’ The city wants her citizens to be more conscious in their decision- making when choosing by which means of transportation they want to reach their destination. In order to realize this, seven policy decisions and related actions have been stated:
◊ A sustainable and healthy city; the expansion of the use of cycles (by 30%) and public transport (by 40%) by 2020. The growth of car traffic has to be limited to 10%. And the use of alternative fuels and electricity is encouraged. ◊ Choosing for public transport; tram lines will be upgraded to the level of Randstad rail by exploiting bigger trains, introducing new stops, presenting dynamic travel information, high speed lines and higher intensity. ◊ More and often by bike; Improving cycling routes and building more bike-parking spaces will increase the use of bikes, enhancing people’s health and reducing the use of cars. ‘Star routes’ ensure safe and fast connections from the residential areas to the city centre with priority for bikes; by 2020 ten of these routes have to be finished. ◊ Bundle, order and fit in car traffic; ongoing car traffic will be concentrated on well circulating main routes which all support their own city districts. Other initiatives are dynamic traffic management, redesigned intersections and better parking facilities towards and in Scheveningen in combination with public transport. ◊ Room for pedestrians; Pedestrians will get more space around (tram) stations and in shopping areas. Also, barriers to green recreation areas have to be breached in order to connect pedestrians. ◊ Excellent chain mobility; transfer times have to be optimized between different means of public transport and other kinds of transport likecars and bikes. Therefore the municipality invests in more P+R places and also in bike parking at stations and tram stops. ◊ Quiet and dedicated residential areas; to keep the city liveable, car traffic will be concentrated on main routes around residential areas. Within these areas pedestrians and bikes get priority. Removing the ongoing traffic from the neighbourhoods will make room for greener streets.
69 8.2 Conclusion and Conflicts of Interest.
Urban heat does not play a significant role in the assessed policy documents of The Hague. Nevertheless, there are actions and ambitions in the several policy documents which will affect the heat in the city, in a good and a bad way. Examples of planned actions which conflict with heat mitigation are:
◊ densification is planned in the already densest parts; ◊ the proposed water bodies might lead to more heat storage; ◊ investing in too much green might lead to loss of quality; ◊ new green structure is only proposed in already green parts in the city; ◊ improving traffic circulation will not reduce the use of cars.
The planned actions with mitigating potential are summarized table 8.1 and mapped in figure 8.1. Most actions involve urban renewal or renovation of urban structures and it is particularly these kind of projects that offer the best opportunities for the integration of climate adaptation measures (Drunen & Lasage, 2007). In appendix 4 the actions have further been sorted in short- and long term projects. This will be useful when doing the design studies.
Table 8.1; Summary of existing policy for cliamte adaptation (right page).
Number of document (execution date) 1. Structure Vision The Hague (2020) 6. Energy Vision (2040) 2. Social Economic Agenda (2020) 7. Water Plan (2027) 3. Memorandum Public Space 8. National Heat Plan 3a. Urban Rreen in The Hague 9. Action Plan Air Quality (2015) 4. Climate Plan (2040) 10. Momorandum Sustainability 5. Housing Vision (2020) 11. The Hague’s Traffic Policy
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Mitigation Document Short term The Hague on green energy by 2040 1 Densification to avoid commuting 1 After 2020 all houses built will be according to smart building 4 Expansion of the city-heating network and possibly cooling 4 2/3 of heat and electrical energy is produced locally by 2040 6 Shift to cleaner traffic; promotion of electrical vehicles. 9 Upgrade public transport 11
Long term (re)Planting trees in non-green neighbourhoods 3a Connecting 12.000 houses to sustainable heat sources 5 Renovating 10.000 houses to improve energy performance 5 Rebuilding 9000 bad condition corporation houses 5 Urban restructuring of neighbourhoods Transvaal, Schilderswijk/ 5 Central Station area, Leyweg and Havenkwartier Noord Set up of a municipal Sustainable Energy Company 6 Set up of ‘milieu zones,’ dynamic traffic management and improving 9 traffic flow Construction of ‘star routes’ to enhance use of bike 11
Adaptation Short term Improvement and strengthening of (urban) green and the connections 1 to the rural areas (2020) Improvement of the public space (2020) 1 Increase of water retention (325 m3/ha) (2020) 1 Investing in liveable neighbourhoods by planning and projects 2 Replanting trees in neighbourhoods which lack green quality 3a Recreational water in the city 7 Bundling car traffic and leading cars around neighbourhoods creates 11 space to add green
Long term Collaboration with private parties for project development 3 Promoting to re-green inner courts and private gardens 3a Introducing more green in neighbourhoods Zuidwest, Mariahoeve, 5 Kijkduin, Lozerlaan, Erasmusveld and Vlietzone Enhancing awareness on what to do during heat 8 Completion of Rotterdamse Baan will make more room for greener 11 street profiles Connect residential areas to green areas 11
71 Figure 8.1; Potential map from the policy assessment
Visions in The Hague Energy
Windpower
“Municipal sustainable Thermal heat energy board” City-heating Networks
Transport
Rotterdamse Baan and Centrum Ring
Buildings
Urban restructuring
(re)Building energy efficient houses
Development of green edges
Densification of the city core
Ecology
Water structure
Swimming water
Green edges
New green
Green connections
0 0,5 1 2,5 5 km
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Figure 8.1; Potential map from the policy assessment
Visions in The Hague Energy
Windpower
“Municipal sustainable Thermal heat energy board” City-heating Networks
Transport
Rotterdamse Baan and Centrum Ring
Buildings
Urban restructuring
(re)Building energy efficient houses
Development of green edges
Densification of the city core
Ecology
Water structure
Swimming water
Green edges
New green
Green connections
0 0,5 1 2,5 5 km
73 IV Integrated Strategies
74 9 Design Studies
In order to give an advice to the municipality of The Hague on how to mitigate heat problems in the city, three design studies will be performed. These studies each focus one criterion which determines area’s vulnerability for heat and come up with strategies to resolve specific problems. The criteria, as described in chapter 7 are ’hot spots,’ elderly, livability, green structure, building energy labels and density. The preformed studies focus on elderly, green structure and density, since these criteria offer possibilities for urban design measures or, in case of the elderly, can be used to determine priorities for actions.
Mitigation Strategies
The conclusions of the literature study, the comparative analysis and the policy assessment are used to develop heat mitigation strategies. The catalogue to influence the Microclimate, developed by Sanda Lenzholzer (Lenzholzer 2013) is used to illustrate how these strategies can be turned into actions.
The next step is to turn proposed actions into urban design; this is when programme becomes site specific. This can be done by using the Pattern Language for Heat Mitigation developed by Daphne van Dooren in her thesis Warming Up for the Cool Down. This document offers a method to evaluate specific sites and propose suitable measures to mitigate heat in a location.
75 76 10 Green The Hague
The omission of a green structure is a major factor in determining an area’s vulnerability for heat. The cooling effect of green structure is made visible in figure 10.1. It is clear that there where green is present, there is hardly any heat. What happens is that in the green areas the canopies of trees absorb radiation and provide shading to the ‘hard’ surfaces. Furthermore plants and trees cool their surroundings by evaporating water. In the non-green areas impervious surfaces like facades and pavement are directly exposed to the sun and warm up. In order to bring down the temperature in the warm areas, ways have to be found to introduce a strong green structure.
Both Lenzholzer and CPC describe a couple of criteria for a healthy green structure; the green structure should consist of a network of smaller green spaces in dense built-up areas, rather than one large park. During warm days small parks or squares have to function as ‘refuge areas,’ where people can find relief from city heat. at night-time open, green surfaces are desired because they cool down quickly and thus cool their surroundings (Lenzholzer, 2013).
Preventing heat in the city is not only important to ensure outdoor comfort. Indoor comfort is also affected by outdoor temperatures; higher indoor temperature results in lower living comfort and thus affects people’s health. There has been done little research on this topic; however TU Delft is conducting a project in Rotterdam called Hotterdam, which looks into the relation between indoor and outdoor temperatures.
Urban heat compared to green structure Figure 10.1; Heat By combining the maps of Green the green structure and 1. No green 2. Green the heat it is made visible 3. Young green that there where green is present, there is hardly any heat and vice versa. In
1. the non-green areas solar radiation is turned into heat when it reaches pavement 3. and facades. In the green areas the canopies of trees in the green areas absorb 2. solar radiation and provide shading of ‘hard’ surfaces. Map by author. 0 0,5 1 2,5 5 km
77 Figure 10.2; Non-green areas are characterised by high densities, the omission of green structure and often low liveability. Source image: Regentessekwartier, Bingmaps.
Figure 10.3; Green areas can be found outside the city core and are characterised by an abundance of urban green and lower densities. Source image: Bouwlust, Bingmaps.
Figure 10.4; Young green areas are characterised by a young green structure not yet offering enough protection from direct solar radiation to effectively cool the surrounding. Source image: Leidscheveen, Bingmaps.
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10.1 Green in The Hague In the Social Economic agenda and the Urban Green Plan the municipality of The Hague explains the ambition to add more green to the following parts of the city; Zuidwest, Mariahoeve, Kijkduin, Lozerlaan, Eramusveld and Vlietzone. However, looking at the green structure, these areas are already the greenest of the city and are thus not important for further greening. In order to develop a effective green strategy to mitigate heat, we take a brief look at the different types of green areas present in the city (see also figure 10.1):
1. Non-green; the lack of green structure and high densities results in warmer areas compromising living conditions. These areas are the city core and surrounding neighbourhoods and Scheveningen (figure 10.2); 2. Green; an abundance of green provides sufficient shading and evaporation to avoid areas from warming up. These areas lie outside the city core, are dominated by medium high apartment buildings and have been erected after WOII (figure 10.3); 3. Young green; new neighbourhoods with not fully grown green structure not yet providing enough cooling capacity. The VINEX-neighbourhoods Ypenburg, Leidscheveen and Wateringseveld, but also larger urban renewal projects, suffer from this.
The urban green structure is not only restricted to the public space. On city level, roof surfaces and private back yards offer vast areas which can be added to the city’s green structure. Therefore participatory project have to be made part of the strategy:
4. Private inner courts; these appear in The Hague either very green or fully paved/ built-up and have as such great influence on the outdoor and indoor temperatures; 5. Flat roofs; asphalt roofs become very hot during warm days, influencing the immediate surroundings.
The strategy developed focusses on the warmer, non-green parts of The Hague, but also gives recommendations for the other areas. The Green The Hague strategy is presented in in figure 10.17.
79 10.2 Non-green Areas The city core and Scheveningen are characterized by enclosed building blocks of 2 to 4 stories high, with private gardens on the inside, narrow streets and few impervious public spaces. The lack of green structure and high densities make these areas vulnerable for heat. There are several measures to introduce more green in these areas; these will be discussed in the following paragraphs.
10.2.1 City Streets The narrow street pattern of The Hague follows the natural dune pattern (figure 10.5) with residential streets running along the coastline (figure 10.7), regularly interrupted by thoroughfares, perpendicular to the coast (figure 10.8), making traffic circulation possible. The dense network provides few squares, making that people have to use the streets for transportation, shopping and living. The Traffic policy-document The Hague states the ambition to concentrate car traffic around neighbourhoods, creating quiet and save living environments inside the neighbourhoods. The removal of traffic out of the neighbourhoods also makes room to for new green structure. Two principles for determining which streets are suitable for greening are given below.
Figure 10.5; Figure 10.6; The Hague built Coastal wind on dunes. systems. Data from NHK, Image by map by author. Lenzholzer, 2011.
Natural Air Movement During heat waves large-scale wind systems are weak and get taken over by local coastal wind systems, which move cool air from the sea into the city (figure 10.6) (Lenzholzer, 2013). In The Hague these coastal wind systems can be used to provide extra cooling during warmer periods, when streets are designed to channel this air-flow. To enhance the air-flow fresh air corridors should be kept free of extensive planting of tree. Buildings have to be designed to better conduct the air-flow (Lenzholzer, 2013).
80 Green The Hague
Figure 10.7; Example of a residential street along the coast. Most of these streets are dominated by parking and lack sufficient green structure to keep ‘hard’ surface cool. Picture by author.
Figure 10.8; Example of a thoroughfare. On these wider streets traffic from the neighbourhoods is collected and circulated throughout the city. Picture by author.
81 Green Structure In order to facilitate the free movement of air, the thoroughfares around the neighbourhoods will be kept free of extensive planting of trees, although the planting of some trees will be desired. When traffic gets bundled on the more open thoroughfares and no longer runs through the neighbourhoods, as is proposed in the Mobility Policy-document, room will be created for the planting of trees. This will cool the area, increase the liveability and therefore lower the areas vulnerability to heat. Residential streets should be used to implement green structure. This can be done by the planting of trees. When streets are too narrow or underground infrastructure hinders the planting of trees, there are other measures to add green in these streets. These are listed in chapter 10.7.
Figure 10.9; Figure 10.10; Lack of green structure exposes ‘hard’ surfaces Street trees offer sufficient shading and add to the directly to solar radiation, warming-up the area. city’s green structure. Fultonstraat, Den Haag. Herzogstraat, Den Haag. Picture by author. Picture by author.
82 Green The Hague
10.2.2 Urban Wasteland The dense city core leaves little space for urban relief in the form of squares and parks. Urban wastelands; empty plots and unnecessary parking lots can be transformed into accessible public spaces which offer (temporary) program like urban gardening and can form refuge areas during warm days. Vacant plots can be made accessible by removing fencing and dirt. The ground can be covered up with wood chips and plants can be put in, movable if desired.
10.2.4 Example Project: Prinzessinnengarten in Berlin An example of such a project is Prinzessinnengarten in Berlin, here food gets grown and cooked in a plot where urban development could not go through. The areas now offers a green and cool area where people can meet during the day (figure 10.11/12). Because everything is planted in containers, the whole garden can be moved when development picks up again (prinzessinnengarten, 2014).
Figure 10.11; Prinzessinnen garten, Mortizplatz, Berlin can be accounted as a successful greenfication of a wasteland. Source: www. Prinzessinnengarten.net
10.2.4 Wastelands in The Hague There are several locations in the Centrum where change of land use can be beneficial. The locations of these are highlighted in figure 10.9.
6. Parkinglot, Gedempte gracht, Centrum; 7. Square, Schalkburgerplein, Transvaal; 8. Empty plot, Loosduinsekade 101, Transvaal; 9. Development area, Laakkade, Laak; 10. Empty plots, Loevesteinlaan, Morgenstond; 11. Empty plot, Zeesluisweg 76, Scheveningen; 12. Stagnated developement area, Binckhorst.
83 10.2.3 ‘Swimming Singels’ The Water Plan (2007) indicates two locations, Kraaienstijn and Ypenburg for the development of safe and clean swimming water. However, these water-locations are more needed in the city core. Therefore it is recommended to move these projects to the city core.
The existing water structure of The Hague is characterized by high embankments and a lot of parking. By removing parking from the quays and introducing natural banks people can get closer to the water and find relief during warm days. Another measure is to build a swimming pool inside the water area. Several examples from Berlin, New York and London can be used as a reference (figure 10.13). Though these measures might seem rather rigorous, it fits within the ambitions of the Water Plan to make water a more integrated and living part of The Hague.
Further, bringing recreational facilities into the city makes them accessible for more people, including the elderly and less mobile groups.
10.2.4 Industrial Areas In the industrial areas Binckhorst and Kerktuinen- Zichtenburg the surface temperatures easily rise 10 ˚C higher than other places in the city. In order to bring down these temperatures, entrepreneurs in these areas have to be challenged to contribute to a greener environment. Solely planting trees in the public space won’t be enough, since they can never cover the roofs and yards of the warehouses.
Intensive green roofs and pervious (parking) in public and private space are measures fit for the scale of these areas.
The municipality can – in addition - use tax-discounts, grants and decide on a zoning plan to get these measures executed.
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Figure 10.12; An urban wasteland turned into an urban garden and forming a meeting place. Vegitation is planted in containters, so the whole garden can be moved to another location. Prinzessinnen garten, Mortizplatz, Berlin. Picture by author.
Figure 10.13; ‘Swimming Singels’ can be developed in the same way as Badeschiff in Berlin. Here an old barge is turned into a pool, offering relief during warm summer days. Badeschiff, Berlin. Source image: http://www. roughguides.com/
Figure 10.14; ‘Leefstraten’ in Gent offers residents to make their streets car-free for two months. What happens in the created free space is up to residents. Pussemierstraat, Gent. Source image: http://www. leefstraat.be/
85 10.3 Green Areas The greener and less dense neighbourhoods outside the city core show to be less vulnerable for heat. The neighbourhoods are characterized by two types of building structures; enclosed building blocks 2-3 floors high with private gardens or linear apartment buildings, 4-15 stories high surrounded by green.
10.3.1 Refuge Areas This research has turned out that these areas are less vulnerable for urban heat. This is due to the presence of green structure, lower population densities and higher valued liveability. However, that does not mean that these areas won’t develop risks related to heat.
As explained in the introduction, cities need green open surfaces during the night for they cool down quickly and thereby cool their surroundings. During the day ‘refuge areas’ are needed in which people can find relieve from heat. This can be done in (small) parks or squares which offer an abundance of shading and evaporation of water by vegetation or fountains. Making sure that people can find heat relieve outside their own homes prevents social isolation during warm periods and also avoids the need to run air conditioning when indoor temperatures result in uncomfortable conditions (Lenzholzer, 2013).
For both the Refuge Areas as the Swimming Singels strategies and in general, citizens prefer the realization of smaller green projects in their direct surroundings over the construction of large recreational areas further away. This was concluded in a research carried out by Lagas and Diederiks under the population or Rotterdam in 2011 (Lagas and Diederiks, 2011).
10.3.2 Follow-up Research; Locations and Indoor Temperatures More research has to be done into the right placement of the refuge- and open areas; that would take this research too far. Follow-up research on these locations would is recommended especially when combined with the registration of indoor temperatures, to see if houses in the green areas heat less than the houses in the warmer areas.
86 Green The Hague
10.4 Young Green Under the VINEX-act (1991) The Hague had to build three new neighbourhoods; Ypenburg, Leidscheveen and Wateringse Veld (VROM, 1991). Despite the fact that these neighbourhoods were often designed with great attention to green structure and have relative low densities, these areas show significantly warmer on the heat map. This is not caused by the lack of green structure, but because the green isn’t fully grown at this stage, and thus not providing enough shading to cool the surroundings.
10.4.1 Temporary Measures Trees planted in these neighbourhoods might need another 10 to 20 years to be fully grown and in the meantime will not offer sufficient shading of streets and facades. Until then temporary measures can be taken to mitigate heat in these areas:
◊ installation of sun shading; ◊ planted green screen elements; ◊ built in shadow elements; ◊ prinkling streets or fountains; ◊ de-paving areas; pervious parkinglots (Lenzholzer, 2013).
10.4.2 Follow-up Research; Elderly and Maintenance Despite that these young-green areas appear as warmer areas on the heat map, the situation in these areas is not problematic. Attention must be paid to ageing in these areas. Nowadays the percentage of elderly living in these neighbourhoods is low, but this will change in next decades. This is investigated further in chapter 12.
It is recommended for these areas to keep track on how the green structure develops. When trees get old, they eventually have to be replaced. If new trees get planted well in time, sufficient shading can be maintained.
87 10.5 Green Inner Courts The previously discussed measures all focused on the green structure in the public space. However, measures on private grounds can also be added to the city’s green structure.
Paved gardens and garden sheds with asphalt roofs generate a lot of heat within the courtyards. Planting vegetation and trees and replacing impervious surfaces for pervious surfaces will reduce heat problems. Coordination on the planting of big trees will be necessary, since too many trees will obstruct air-flow and keep heat in the inner court.
10.5.1 ‘Haagse Tuintjes’ (idea by Frank van der Hoeven) The municipality already offers occasional grants for greening inner courts under the Tree Plan. To stimulate citizens even more to green their gardens, the municipality could offer help by planting trees in their gardens: the municipality has equipment and experience which the citizens do not have. In return the citizens can clean-up the rest of the garden and plant smaller vegetation.
Professional parties like garden centers and farmers can be engaged in these projects; farmers can provide critical knowledge for successfully running urban food gardens. Garden centers, stimulated by the municipality can offer discounts and advice to people who plan to green their garden. In combination, garden centers can also provide ‘service contracts’ which provide clients with maintenance schedules and from time to time offer seasonal planting or equipment.
10.5.2 Communal Inner Courts Garden With Me! (Tuinier met mij mee!) is a citizen initiative in Rotterdam-Noord which transforms neglected inner courts into communal food gardens of which the products get cooked up in a local kitchen. This private initiative is interesting because it turns larger unused impervious spaces into green areas,Haagse without tuintjes the interference of the municipality. Municipality Home owners
Figure 10.15; ‘Haagse Tuintjes’ actor involvement. Image by author.
Garden center 88 Green The Hague
10.6 Green Roofs Green roofs applied on small scale will not have an effect on urban heat. Only used at a largest possible scale, green roofs can have an effect on lowering heat in the city (CPC 2015 and Lenzholzer 2013).
However, green roofs effectively lower indoor temperatures. An extra advantage of extensive green roofing is that rain water gets retained, putting less pressure on the sewage systems and intensive vegetated green roofs increase the cities biodiversity. The installation of green roofs is fast and easy and has immediate effect. Suitable roofs for greening can be found mainly in the city core and the surrounding neighbourhoods. Combining green roofs with photovoltaic panels can make the energy system more efficient, and this will add to the ambitions stated in the Energy Vision.
Green roofs can be applied on single houses or be developed over an entire housing block or utilitarian buildings under the auspices of the municipality, the housing corporation or the house owners association, the result of this can be seen on the left side of figure 10.16. Individual development is also possible, though the effect is smaller as can be seen in the top right of figure 10.16.
Figure 10.16; Example of how roofs in The Hague can be used to add to the green structure of the city. In the left a ‘block-wise approach’ and on the right the individual approach. Source image: Bingmaps, edited by author.
89 10.7 Phasing Urban green needs time to grow up, therefore short term and long term measures should be used simultaneously, table 10.1. Green roofs, temporary shading elements and moveable awnings have immediate effect. To save money measures can be implemented with regular maintenance work of paving and underground systems. Only in Scheveningen immediate measures are needed. The lack of shading on street level causes higher temperatures, causing health threats towards the older population.
Table 10.1 Mitigation by Phasing Measure Evaporation Shadow Conductivity Long term Short Term Street trees Ο Ο Ο Espalier trees Ο Ο Ο Green facades Ο Ο Ο possible Green screens Ο Ο Green backyards Ο Ο Ο Ο Ο Green roofs Ο Ο Ο Low plants/ urban gardening Ο Ο Ο Ο Ο Low density surfacing Ο Ο De-paving areas Ο Ο Ο Sprinkling streets Ο Ο Temporary shading Ο Ο Movable sunscreens Ο Ο
10.8 Actors All measures planned in public space fall under the responsibility of the municipality and the boroughs. Measures taken around the house come for account of the home owners or corporations, who own the houses. The municipality can apply grants to support or stimulate private parties to invest in their dwellings, buildings and inner courts.
Active citizenship is supported by the Memorandum Public Space. The municipality is convinced that this will benefit society since it engages public in projects and can prevent isolation. Especially elderly people benefit from community projects in their surroundings. The temporary program of the urban wasteland-projects can be drafted in collaboration with citizens. Citizens can also be engaged by consulting their needs when streets and squares are being refurbished.
Professional parties are important when they own objects which need renovation. Apart from those, also commercial parties can get involved in greening projects. Garden centres and farmers can help in the development of inner courts or gardens.
90 Green The Hague
10.9 Policy Room for active citizenship is already part of The Hague’s Structure Vision. Most of the other proposed measures for a greener The Hague can also be put under existing policies:
◊ Green residential streets along the coast and open thoroughfares along the coast fall under the structure vision (2020) and the Memorandum Public Space; ◊ Types of green used in residential streets can be determined in the Tree Plan and the Frame Work Policy Document Public Space; ◊ Swimming Singels can be executed under the Waterplan; ◊ Temporary use of urban waste lands can be covered by the Memorandum Public Space; ◊ Refuge areas are similar to the swimming areas proposed in the Waterplan (2007), Swimming Singels provides new locations; ◊ Wet streets and wadi’s in the young green areas can be put under the ambitions in the Waterplan to make water more visible in the streets.
In order to make private parties invest in mitigating urban heat, the municipality can use rewards or punishments.
◊ Grants for green back yards and green roofs are already being supplied through the Urban green-plan; ◊ Discount on taxes when citizens actively engage in greening their surroundings, like back yards and public spaces (Tree Plan); ◊ Discounts for entrepreneurs and businesses when they adopt greening strategies in their working methods (Energy Vision 2040); ◊ Rewards for entrepreneurs for having energetically well performing accommodations, installing green roofs and/ or planting trees around their premises (Energy Vision 2040).
Finally, green gardens and roofs should be added to the municipality’s green structure to develop a strong green structure, even when streets are too narrow for interventions.
91 Figure 10.17 Study 1; Green The Hague Green The Hague Urban areas
1. No green
Sea breeze
Green streets 1. Urban wasteland 2.
Industrial areas
2. Green 6. Urban relief zones
‘Swimming Singels’
3. Young green
Temporary solutions; Street sprinklers and sun shades
Participatory projects
1. Green roofs
‘Haagse Tuintjes’ 3. 7. Green backyards
2.
4.
5.
Existing structure
Forest and parks
Green neighbourhoods
Young Green
Water structure
0 0,5 1 2,5 5 km
92 Green The Hague Figure 10.17 Study 1; Green The Hague Green The Hague Urban areas
1. No green
Sea breeze
Green streets 1. Urban wasteland 2.
Industrial areas
2. Green 6. Urban relief zones
‘Swimming Singels’
3. Young green
Temporary solutions; Street sprinklers and sun shades
Participatory projects
1. Green roofs
‘Haagse Tuintjes’ 3. 7. Green backyards
2.
4.
5.
Existing structure
Forest and parks
Green neighbourhoods
Young Green
Water structure
0 0,5 1 2,5 5 km
93 94 11 Dense The Hague
The Hague is expected to grow to 570.000 inhabitants (14% increase) by 2040 (CBS, 2013). By the ambitions of the 2005 Structure Vision, this growth number will be met by an increasing built density and the use of the city surface in the city core. Specific locations for development are the neighbourhoods Binckhorst, Transvaal, and Laakhavens, the coast, the Vlietzone and the green city edges of the city.
In the 2009 Housing Vision the following actions have been formulated to execute the ambition; the built of 25.000 new houses before 2020, of which 9000 corporations-owned houses are set to be rebuilt. Other actions involve the renovation of another 10.000 houses and the connection of 12.000 houses to the existing city heating networks.
As concluded in the literature study density is a critical factor for the forming of urban heat islands (CPC, 2015). Therefore further intensification of land use in the already warm city core of The Hague has to be done with caution. Development in the other locations might be less harmful if possible forming of urban heat islands is taken in account. This means that care has to be given to the amount to the ratio between pervious- and impervious surface and the green structure.
Density comapred to heat
Low density, cool
High density, hot + 5,7% + 4,5% Projected increase population Figure 11.1; The denser areas in The + 4,8% Hague relate to higher temperatures. The + 2,1% + 5,6% expected increase in population is highest in the + 4,9% cooler areas of the city. + 4,5% Map by author. + 3,1% + 7,5%
0 0,5 1 2,5 5 km
95 11.1 Dense The Hague Figure 11.1 shows that denser neighbourhoods of The Hague are hotter than the less dense areas. On top of that the projected population growth per borough is given. These numbers show that most growth is expected in the cooler boroughs (Starmans & Vermeulen, 2012). Though this is positive for the mitigation of heat in the city, it also contradicts with the ambitions of the municipality to increase the density in the city core. This strategy looks into which locations in The Hague can be developed in relation to the ambitions of the city, the expected growth and heat. This has resulted in the following strategies, which have been mapped in figure 11.2.
1. de-densification; lowering density is acquired by restructuring and rebuilding lesser houses; 2. renovation areas; network is maintained and houses get renovated or rebuilt; 3. densification areas; density gets increased by adding more buildings; 4. new development; new locations are found to develop; 5. city centre; priority for economy over climate.
Apart from these strategies, there are also a couple of key projects to be appointed:
◊ development focus zones; active parts of the city in which development can take place to maintain population density but creating room for green structure; ◊ city-heating networks; providing sustainable solutions for heating and cooling of houses and providing opportunity for introducing new green structure.
11.2 De-densification Areas These areas are characterized by 19th century building blocks usually four floors high. The lack of green structure, high population density and low liveability make these vulnerable for urban heat and therefore immediate action is needed. In order to mitigate heat problems a new green structure is strongly recommended. To increase the liveability these areas will be renovated according to the Housing Vision.
The renovation of these areas has been going on since the 90ties with the rebuilding of the Vaillantlaan by the design of Jo Coenen between 1990 and 2009. In this project two principles were used; rebuilding houses to modern standards will
96 Dense The Hague
increase comfort and liveability. Next to that fewer houses were rebuilt than were demolished, slightly lowering densities (Ravestein & Knijnenburg, 1996). Rebuilding lesser houses could be combined with restructuring of public space, to increase the amount of green structure in the area.
11.3 Renovation Areas In the renovation areas the chances for heat stress are considerable. However they do not require immediate action because of the lower densities and better liveability.
Green structures can be added with regular maintenance of streets or when city- heating gets installed. The policy decision in the Mobility policy-document to de- intensify neighbourhoods from car traffic will also lead to new opportunities for the introduction of green structure.
In renovation of public space attention has to be paid to the balance between pervious and impervious surfaces and the right amount of shading in the streets.
11.3.1 Leefstraten (Gent), Droomstraten (Rotterdam) Leefstraten (living streets) in Gent and Droomstraten (dream streets) in Rotterdam ‘Living streets’ in Gent is a project in which residential streets are made car free for two months and it is up to the residents to decide what to do with the free space. With this project ideas rise how to increase the amount of green and room in the city, as well as they create room to experiment with alternative means of transportation (figure 10.14).
Next to that the project increases social cohesion and a participative society. Residents apply for the project in groups and remain responsible for the execution, maintenance and cleaning up of the street during the two months. An organization has been founded to guide residents to start their project.
During the summer of 2015 a similar project will run in Rotterdam (Verkaeke, 2015).
This project could be used in The Hague to increase the green structure, as well as help with the execution of the policy decision made in the Mobility Policy-document.
97 11.4 Densification Growth areas are appointed in relation to the lower chances to heat stress and the ambition of the municipality to increase density close to the city center, as stated in the Structure Vision. When these areas are developed, it is essential to be sure that heat will not become a problem. Therefore attention must be paid to the balance between pervious and impervious surfaces and right amount of shading in the streets.
11.4.1 International Zone The international zone’s green character close the city center, low population density int and abundance of empty offices forms interesting locations to investigate possibilities for development and densification. This has been carried out in ValueLab (2014) as part of the project “Herbestemmen als Gebiedsopgave” (realloacation as an area assignment) commissioned by the ministry of Infrastructure and the environment.
The conclusion was that the current and future stock of empty (office) buildings located in the international zone, offers great opportunities for the international ambitions of the city stated in the Structure Vision as well as for her population (ValueLab, 2014).
Figure 11.2 Development focus zones are located in already active parts of the city, in order to concentrate functions and decrease travelling distances. The image shows the Hobbemaplein between Schildersbuurt and Transvaal. Image by author.
98 Dense The Hague
11.5 New Extensions There are a few locations within The Hague’s municipal borders where new development can take place. These locations lie mainly on the edge of the city and inquire negotiation with neighboring municipalities for development. The most interesting location is along the Vliet-canal, where new residential areas can be developed in collaboration with the municipality of Rijswijk.
11.6 City Center The role of the city center conflicts with the criteria needed to prevent heat stress. The high population- and built density, and the intensive use of public space make it hard to fit in sufficient green structure. The anthropogenic heat produced by traffic, buildings and other processes contradicts with heat mitigating ambitions. For the city center therefore considerations have to be made in specific locations to whether the chances for heat stress or economic prosperity is more important. This should result in different strategies for the commercial part and the residential part of the city center. 11.7 Development Focus Zones The Structure Vision proposes a couple of strategic locations for further development. These locations have been evaluated and some new locations are added in relation to heat. When these zones are located in warmer areas, heat has become subordinate to economic interest, like what happens in the city center. In these areas medium high rise buildings or iconic structures can be used to increase population density, but not the built density, leaving room for green in the public space. These locations can be developed as commercial nuclei, bringing daily functions closer to the people preventing unnecessary travel (Krier, 2007).
11.8 City Heating Networks The Housing Vision the city of The Hague expresses the ambition to connect 12.000 houses to the city’s heat network before 2020, since that can offer a cleaner and a more sustainable heating of houses during the winter. If the installation of the pipes is combined with the rearrangement of the underground infrastructure room can be made for planting of trees in the streets.
99 11.9 Phasing The short term ambitions from the Housing Vision and the Structure Vision will help mitigating heat in some places. Attention must be paid to the densification of the city structure in some areas, since this might increase heating issues. In some places the program needs to be altered or stopped, since further intensification will be lead to more heat problems.
On the long term attention has to be paid to the ageing of the population, which will become more visible after 2020. New legislation on this matter will change the demand for housing and design of public space (see chapter 12).
11.10 Actors It is crucial that the municipality collaborated with the home owners, which in most cases are housing corporations, to guarantee successful projects. Housing corporations can be persuaded into action by offering discounts on taxes, grants or punishment when they do not comply. Development of new projects can be initiated by the municipality or project developers, in which case the municipality has to demand from the third parties that they work according to the developed strategy to avoid future heat problems. Other parties like banks and insurance companies can also invest in projects. Retirement agencies often do project development as a way to ensure suitable housing for their clients. The Structure Vision 2020 expects that an integral approach to development will lead to new partnerships.
100 Dense The Hague
11.11 Policy Most of the plans from the Housing Vision and the Structure Vision can be carried out, with the restriction that the southern part of the city core should not be made any denser. Densification in the northern part of the centre will be fruitful around the international zone, where many empty office buildings are waiting for new functions (ValueLab, 2014). When densification is really desired, high rise can be used to house people above the hot street network and make room for green structures on ground level. For certain areas, economic motives can make the need for heat mitigation subordinate.
Heat mitigating measures can often be implemented during redevelopment of certain areas. The city heating networks proposed by the Energy Vision will improve indoor comfort of houses greatly, under the condition that the houses also get renovated during the process. This is especially important for warmer periods, when extra insulation prevents indoor temperatures to rise. It is also important that natural ventilation remains possible, since this proofs to be the cheapest and best way to cool down houses (Climate Proof Cities 2015) and decreases the need to run air conditioners.
101 Figure 11.3 Study 2; Dense The Hague Dense The Hague Urban areas
De-densification areas
Renovation areas
Living streets
Densification
International zone int
New extentions
int City center
Development proposed by Structure Vision 2020
Development focus zones
City-heating Networks
Existing structure
Forest and parks
De Vliet
0 0,5 1 2,5 5 km
102 Dense The Hague Figure 11.3 Study 2; Dense The Hague Dense The Hague Urban areas
De-densification areas
Renovation areas
Living streets
Densification
International zone int
New extentions int City center
Development proposed by Structure Vision 2020
Development focus zones
City-heating Networks
Existing structure
Forest and parks
De Vliet
0 0,5 1 2,5 5 km
103 104 12 Healthy Ageing in The Hague
Elderly people have difficulty dealing with heat; people of age have trouble sensing heat and transpire less, making them more vulnerable during periods of sustaining heat (Van der Hoeven & Wandl, 2013). There are several studies on future dispersion of the elderly over The Hague (Burger, 2006; Starmans & Vermeulen, 2012). By including this information in the adaptation strategy it can be prevented that new problem arise in other areas of the city in the future. This will according to Lagas en Diederiks save forthcoming high costs for healthcare, energy costs, and increase real- estate values (Lagas & Diederiks, 2011).
12.1 Housing of the Elderly During the past years it has become national policy to let elderly live in their own houses as long as their health permits them to. Municipalities have been appointed to safeguard and monitor this by offering services to maintain self-reliance. This includes technical improvements to the house, professional care at home and support by family, friends and neighbors (Rijksoverheid, 2011).
Elderly have to be able to participate in society like any other, which means that the following criteria have to be met in their daily lives:
◊ right housing; single story housing with an elevator if needed to access and a bathroom on the same floor as the bedroom; ◊ in the proximity of their daily urban functions like supermarket, bakery, butcher, convenience store, café, community center; ◊ in the proximity of healthcare/ health center providing hospital, general practitioner (GP), dentist, pharmacy, personal care; ◊ public space which engages to meet others (prevent isolation), recreate and participate in social activities and is safe (Rijksoverheid, 2011).
In order to make this possible a program ran on national level to realize 44.000 homes built for the needs of elderly every year till 2021. This development was stopped in 2008 due to the financial crisis and afterwards the policy changed to adapting existing homes into suitable residences (Rijksoverheid, 2011). This program was a preliminary action, to be backed by an action plan Elderly Care (due in 2013) which never appeared because by that time responsibilities had been decentralized to the municipalities (ANBO, 2013).
105 12.2 Elderly in The Hague By 2020 14,5% of The Hague’s population will be older than 65. The share of people older than 55 will be 26,2% for the whole of The Hague. In 2040 over 20% of The Hague’s population will be older than 65 (CBS, 2013; Starmans & Vermeulen, 2012).
Figure 12.1 shows the expected increase of 55+ by 2020 per borough. Major growth can be seen in the city core, Laak and Ypenburg/Leidscherijn and already high concentrations in Haagse Hout and Loosduinen (Starmans & Vermeulen, 2012).
When comparing these numbers to the absolute number of 55+ per neighbourhood in figure 12.2, it is clear that the majority of the elderly is living in the cooler boroughs as Loosduinen and Escamp, but that a significant amount of young elderly will live in warmer areas by 2020 (Burger, 2006). If no further actions are taken, by 2040 many more elderly will be exposed to urban heat in the city core and Laak.
12.3 Renovating Dwellings This strategy builds on the execution of the two proposed strategies for green structure (chapter 10) and density (chapter 11). The case of the elderly adds to the proposed programs and gives extra urgency for actions to mitigate urban heat.
12.3.1 Non-green Areas Planned restructuring and renovation from the other strategies should be combined with the necessary improvement to make houses suitable for elderly. Laak is added as a new location, since the high increase of elderly expected in this area till 2040. Housing in these areas can be made suitable for elderly with the provided guidance of the municipality.
12.3.2 Green Areas Renovation of houses is needed to meet climate goals and retain indoor comfort. Renovations can be carried out under the Climate Plan and be combined with necessary improvements for elderly, guided by the municipality. In these areas the housing corporations will play a major role in the planning.
106 Healthy Ageing in The Hague
Share of elderly by 2020 per borough The Hague Elderly outside ‘hot spots’ in 2015 Elderly inside ‘hot spots’ in 2015 26,2% Figure 12.1; + 13,9% The concentrations of 22,2% elderly compared to heat 22,2% Share of 55+ by 2020 + 8,3% +8,3% Increase of 55+ since 2010 shows that the elderly 30,4% live mainly outside the - 0,2% warmer areas. On top of 24,9% 21,9% that the predicted growth + 12,5% + 22,1% of 55+ till 2020 is projected 17,9% 22,3% per borough. The highest + 17,7% + 100,4% growth is expected in the 43,1% 22,6% warmer city core. + 9,2% + 5,7% Data from Starmans and Vermeulen (2012), map by author.
0 0,5 1 2,5 5 km
Absolute numer of 55+ per neighborhood in 2020
< 1000 1000 - 1900 2000 - 2900 3000 - 3999 4000 - 4999 >= 5000 Figure 12.2; Data collected by Burger in 2006 shows that Escamp and Loosduinen remain the highest number of people over 55 by 2020. However Laak and the Schildersbuurt grow rapidly. Data from Burger (2006), map by author.
0 0,5 1 2,5 5 km
107 12.3.3 Young Green The situation in Ypenburg, Leidscheveen and Wateringseveld will resolve itself. The green structure will provide sufficient cooling by the time the neighborhoods start ageing. Besides the high energy labels in these areas mean that heat will be less of a problem for indoor comfort.
12.4 Heat Plan Besides technical improvements the impact of heat can also be mitigated by education. The National Heat Plan offers guidelines to how to act during heatwaves. The Hague also possesses such a document; however this should be made actual and be distributed under the population.
Informing citizens what to do to prepare for and during sustaining heat will prevent nuisance and alleviate the health effects. Communication can be done via flyers, bill- boards, internet, television and newspaper at far lower costs than the price of many adaptation programs.
On an individual level people can be made aware to keep an eye out for elder people in their surroundings.
12.5 Phasing In 2015 most of the elderly in The Hague live outside the warmer areas, as determined in this research. The share of elderly within these warmer areas will rapidly grow after 2020. In the strategy for the density (chapter 11) the renovation of housing stock has already been described. The necessary adaptation to houses for elderly can be combined with these actions. Besides, the implementation of green structure (chapter 10) will greatly improve the livability of these warmer areas by mitigating urban heat.
108 Healthy Ageing in The Hague
12.6 Actors For redevelopment of housing and public space the municipality and the boroughs have to collaborate with the home owners, which in most cases are housing corporations. These can be persuaded into action by offering discounts on taxes, grants or punishment when they do not comply. Professional parties like banks and insurance companies can invest in projects. Retirement agencies often do project development as a way to ensure suitable housing for their clients.
Home owners can turn to the municipality to call for funding of private climate adaptation projects.
On an individual level people can be made aware to keep an eye out for elder people in their surroundings.
Information campaigns on heat are best initiated short before heat waves in collaboration with the national Heat Plan and KNMI.
12.7 Policy The renovation of houses outside the warmer areas; Loosduinen, Escamp is hardly mentioned in the developed strategies. Separate programs can be developed for these projects, which can fall under the Housing Vision and the Climate Plan.
The Heat Plan should be adopted and put into action when heatwaves are coming up. This is the responsibility of the municipality, but also relates to actions to be taken on national level regarding climate adaptation.
In new legislation on elderly care by the national government, relatives are already part of the care for their elderly. The municipality has proper policy to ensure execution.
109 Figure 12.3 Study 3; Healthy Ageing in The Hague Healthy Ageing in The Hague Renovating dwellings
1. No green
Renovation of urban fabric, dwellings and green.
Renovation of dwellings and green.
2. Green
Renovation of dwellings.
3. Young green
Self resolving.
Communication
Heatplan
Existing strcture
Forest and parks
0 0,5 1 2,5 5 km
110 Healthy Ageing in The Hague Figure 12.3 Study 3; Healthy Ageing in The Hague Healthy Ageing in The Hague Renovating dwellings
1. No green
Renovation of urban fabric, dwellings and green.
Renovation of dwellings and green.
2. Green
Renovation of dwellings.
3. Young green
Self resolving.
Communication
Heatplan
Existing strcture
Forest and parks
0 0,5 1 2,5 5 km
111 112 13 The Hague 2040+
The synthesis of the three design studies results in a five key-actions for the municipality which comply with the currently executed policies, change/ stop policies and/ or propose new policy and create opportunity for collaboration:
◊ City-heating networks; until 2020 at least 12.000 houses will be connected to the city-heating network. The required work in the streets should be combined with redesign of infrastructure, both above and underground to create room for the planting of trees in the residential streets. ◊ Urban renewal; already planned urban renewal has to take place in the neighbourhoods Laak, Schildersbuurt, Stationsbuurt and Transvaal and should include projects for de-densification fall in specified areas. In other places the restructuring of public space should be done in such a manner that room is created for a green structure. ◊ Accessible water; the inner-city water structure can be made part of the recreational networks of The Hague which can offer relief during warm days. This creates opportunity for recreation closer to home, making recreational areas better accessible. ◊ Green with functions; research turned out that people prefer green projects in their surroundings over the construction of recreational green further from the A place where they live(Lagas & Diederiks, 2011). After the crisis green budgets for city green have been cut. When functions get combined with green, feasible business cases could be developed. This can be done already at the Haagse Markt, but more projects can be made throughout the city. ◊ Communication; the Heat Plan is the cheapest and most effective way to make sure heat causes the least amount of damage during warmer periods. Adopting and communicating to the citizens is important.
Participation forms a vital aspect for successful execution of projects. Wastelands, haagse tuintjes, green roofs and facades and green business parks are projects by which the municipality should try to engage citizens, home owners, professionals and commercial institutions in building a climate aware and climate proof city. Green projects have positive influence on health, work productivity, liveability (also negative), property value and energy use (shade) (Lagas & Diederiks, 2011). Maintenance costs for urban green are on the long term lower than they are for paved-up areas (Ruijgrok, 2014) and on top of that they offer opportunity for participation, personal development and community engagement. Technical improvements to buildings result in lower energy costs and higher property values and possible tax benefits when higher energy labels are obtained.
113 Synthesis; heat proof The Hague + The Hague 2040 Municipal initiated actions Heat networks; Expansion of heat network adding green structure in renewed streets
Green structure; Renewal and restructuring of neighborhoods
Development focus zones 6. Renovation
Accessible water;
“Swimming Singels”
Scheveningen/ Kijkduin
Green with functions;
Haagse Markt A
1. Communication;
Heatplan 3. 7.
2.A
4.
5. Participatorial actions 1. Wastelands 2.
‘Haagse tuintjes’
Green roofs and façades
Green industrial areas
Existing structure
Forest and parks
Vliet and Singles 0 0,5 1 2,5 5 km
114 The Hague 2040+ Synthesis; heat proof The Hague + The Hague 2040 Municipal initiated actions Heat networks; Expansion of heat network adding green structure in renewed streets
Green structure; Renewal and restructuring of neighborhoods
Development focus zones 6. Renovation
Accessible water;
“Swimming Singels”
Scheveningen/ Kijkduin
Green with functions;
Haagse Markt A
1. Communication;
Heatplan 3. 7.
2.A
4.
5. Participatorial actions 1. Wastelands 2.
‘Haagse tuintjes’
Green roofs and façades
Green industrial areas
Existing structure
Forest and parks
Vliet and Singles 0 0,5 1 2,5 5 km
115 116 14 Conclusion
This research set out to find ways to integrate measures mitigating urban heat in municipal climate adaptation strategies. The study took place in the city of The Hague, The Netherlands answering the following research question:
“How to further improve climate adaptation and mitigation strategies of The Hague with regard to urban heat with the objective to integrate them into the spatial planning of the city of The Hague?”
In order to answer this question, seven sub-questions have been answered in four parts.
14.1 Part 1; Problem Analysis Answered sub-research question:
◊ What general effect does urban heat have on The Hague and its population?
Analysis of satellite data for this research revealed that even on cooler days The Hague develops a surface heat island. According to TNO the average surface heat islands can be as high as 8,6˚C. This makes The Hague the warmest city in The Netherlands. High population density and a high ratio paved- /built-up area seem to be the main causes of the heat island (Hove et al., 2011).
Higher temperatures in cities have a negative effect on human health. Sustaining heat causes heat stress leading to tiredness, lower productivity and aggression. Especially babies, elderly and people suffering from chronic diseases are vulnerable during warmer periods (Kleerekoper, 2009).
14.2 Part 2; Integrated Strategies Answered sub-research questions:
◊ What climate adaptation strategies are recommended from other research programs? ◊ What can we learn from urban practices regarding climate adaptation on an international scale?
117 14.2.1 Research Programs Both the International Panel for Climate Change (IPCC) and the Dutch Climate Proof Cities-program (CPC) conclude that an integrated approach towards climate adaptation is needed to successfully adapt to climate change. Strategies should consist of a synergy between mitigation and adaptation measures. Policy makers have to find ways to combine individual strategies for urban design, planning, infrastructure and housing into integrated strategies to adapt for climate change.
The role of the home owners and individuals is not to be neglected in proposed programs, since these actors have to contribute on technical or societal levels (Climate Proof Cities, 2015; IPCC, 2009).
14.2.1 International Practice In order to learn from urban practices on an international scale regarding climate adaptation an analysis of Singapore, Stuttgart and Amsterdam was performed. The strategies are stated below:
Singapore uses urban green to offer citizens relief from the heat and moreover as an investment to attract foreign capital. Park developments like Gardens by the Bay may be too expensive for The Hague, but strategies for green roofs as well as facades and projects like Adopt a Park can be adopted by The Hague.
Stuttgart has a long tradition with environmentally aware design. The city uses natural air-flow from the surrounding areas to cool the city. Similar strategies can be implemented in The Hague as well, by creating natural air-flow corridors. Other strategies found in Stuttgart are green roofs, green tram-ways, and roadside greenery.
The conclusions from the Amsterwarm-research propose the development of a climate adaptation strategy which contains the following five components to integrate in other actions: trees and green; green and cool roofs; cool and lesser paving; surface water; energy efficient buildings (Van der Hoeven & Wandl, 2013)
118 Conclusion
14.3 Part 3; The case of The Hague Answered sub-research questions:
◊ Which locations in The Hague can be indicated as vulnerable for urban heat? ◊ What policy and ambition does The Hague currently have on urban heat or related subjects?
14.3.1 Climate Assessment The Hague’s vulnerability for heat has been determined by evaluating risk-factors per neighbourhood. The risk-factors came from the research project Amsterwarm and are the amount of elderly, liveability and the heat in a certain neighbourhoods determined by lands surface temperatures obtained from remote sensing data. Additional criteria are the energy labels of houses, the green structure and the density.
The results were mapped and indicate that Centrum is the most vulnerable borough of The Hague. An integral strategy is needed given the expected population growth, ageing and the city’s ambitions regarding intensification of land use.
14.3.2 Policy Assessment Looking at 12 policies related to the spatial planning of The Hague it can be concluded that heat does not play a role in the city’s decision making. Though, executed policy does provide opportunities for integrating heat mitigating measures in planned programs. Policy on housing and urban renewal combined with green policies and the Energy Plan form interesting opportunities.
119 14.4 Part 4; Integrated Strategies Answered sub-research questions:
◊ How can existing strategies be enriched with climate adaptation measures in The Hague? ◊ What policy changes are needed to support these proposed measures in The Hague?
In order to phrase recommendations on how to mitigate heat in the city of The Hague, three strategy design studies have been done. The studies focused each on how to enhance the city’s green structure, evaluate the city’s densification ambitions and how demographic trends may influence the need for actions. The conclusions of each study have been mapped. The synthesis of these three maps has resulted in a set of key-actions which comply with currently executed policies, change/ stop policies and/ or propose new policy. The proposed actions do not only focus on the municipality, but also ask for involvement of home owners, individuals and professional parties.
The five key-actions are City-Heating Networks, Urban Renewal, Accessible Water, Green with Functions and Communication and are discussed in chapter 13.
14.4.1 Phasing Currently most of the elderly of The Hague live outside the warmer areas, with the exception of Scheveningen. After 2020 the share of elderly in currently warmer areas will rapidly start increasing. This means that adaptations are required before then.
Urban green needs time to grow, therefore short term and long term measures should be used simultaneously. Sun screens on facades and over streets can be used to immediately mitigate urban heat. In the meantime a new green structure has to be developed, since it needs time to grow.
Narrow streets and (underground) infrastructure form difficulty when planting trees. The further lay-out of the city-heating networks as well as the planned and necessary urban renewal/ development/ densification should be combined with the restructuring of public space to make room for sufficient green structure.
120 Conclusion
14.4.2 Actors This research acknowledges four kinds of actors; the municipality, the home owners, individuals and professional/ commercial parties.
All projects planned in the public space fall under the responsibility of the municipality. However, to increase the effectivity of proposed programs collaborations should be set up between the municipality and the other parties.
Active Citizenship can be used to engage individuals in green projects in their surroundings. This is done by consulting their ideas when streets need to be re- paved or wastelands are up for development. Especially the engagement of elderly is important, since it prevents isolation.
Green roofs and -gardens are major components of Green The Hague. Home owners, especially housing corporations, should be persuaded to install green roofs and redesign inner courts. Other technical improvements; to improve indoor comfort or to allow elderly to live longer in their own houses can also be initiated by the municipality. Therefore (professional) help, grants and tax discounts can be offered.
The development of projects as proposed by Dense The Hague can be initiated by the municipality. But professional parties like project developers, housing corporations, retirement agencies, banks and insurance companies are important in the execution.
Information campaigns on heat should be initiated short before heat waves in collaboration with the national Heat Plan and KNMI.
14.4.3 Policy Mitigating strategies can be executed as dedicated projects or be part of regular maintenance. Policy needed to execute proposed programs can often be made part of existing policies evaluated for this research.
Last, a Heat Plan should be developed for The Hague and put into action when heatwaves are coming up. This is the responsibility of the municipality, but also relates to actions to be taken on national level regarding climate adaptation.
121 122 15 Follow-up Research
In the making of this thesis several question have come up, which have not been discussed because answering them would bring the research to far from its goal. These questions long for follow-up research or can be used as recommendation to the policy makers.
◊ Since there is no detailed data available to determine the urban heat island in The Hague, this thesis uses surface temperatures in combination with several critical factors to determine vulnerable areas. Although this method is rather comprehensive, no conclusions can be made on the actual conditions in the streets. If the city plans to thoroughly her heat island, data has to be collected on street level and preferable also in the adjacent houses. This will give insight in the actual conditions and also the relation between the indoor and outdoor temperature. This data can be used to further develop a climate adaptation strategy and keep track of the development of the heat island.
◊ Lenzholzer describes the need to have ‘open green’ to cool areas at night and relief areas covered with green providing cooling by shading and evaporation. Follow-up research could be done on the green areas, to determine how the ratio between open and covered areas can be further optimized. The abundance of green provides sufficient shading during the day; the chance is there that too much heat is retained during the night due to the obstruction of natural air- flow. This research could also be combined with the registration of outdoor and indoor temperatures.
123 124 16 Reflection
This research set out to find ways to integrate measures mitigating urban heat in municipal climate adaptation strategies. Therefore it was conducted within the research theme Urban Metabolism, at the department of Urbanism which focusses on spatial quality, environmental sustainability, live ability and the social wellbeing of future cities (Nadin and Akkerman 2013). Within this theme significant research on urban heat in Dutch cities has already been performed by Dipl. Alexander Wandl msc. and Dr.ir. Frank van der Hoeven (theme: Design of the Urban Fabric), who worked with the municipalities of Amsterdam (Amsterwarm) and Rotterdam (Hotterdam). But with the exception of two master theses in 2009, The Hague was still waiting to get the same academic attention. This research therefore used methodology developed in the Amsterwarm project to determine The Hague’s vulnerability for urban heat, which gave insight in the challenges The Hague faces.
Challenges facing urban heat should be part of cities climate adaptation strategies, but in The Netherlands most attention usually goes out to water defense (Döpp and Albers 2008). This is alarming because the heat wave in August 2003 took 35.000 lives in Europe (Bhattacharya 2003). Combining this with the conclusion of the literature study that has shown that The Hague is the warmest city in the Netherlands (Hove et al. 2011) and also lacks policy on how to address heat (Gemeente Den Haag 2011), the social relevance of this research has been had been answered.
In order to improve the situation in The Hague the research started off with building an inventory of suitable heat mitigation strategies. Therefore recent research projects and comparative studies have been performed. Thereby the following topics have consequently addressed: general city characteristics regarding heat and the ambitions, policy, actions, measures, actors, locations and phasing the municipalities execute. The plans of the municipality regarding climate adaptation have also been assessed in the same way, making them comparable to the inventory of possible strategies. The second part of the research was determining the vulnerability, from which design proposals could be made following the methodology of Amsterwarm. In the design proposals The Hague’s policy are combined with the necessary strategies to make The Hague a livable city during periods of heat.
Initially the plan was to include social cost-benefit analyses to proof that certain measures would make a positive balance. These have been repealed because of lack of time and decreasing necessity in the cause of the research. As turned out many of the actions needed in The Hague are already part of policy, on locations have to changed and actors could be engaged more actively.
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Policy documents
Baldewsingh, R. (2008). Haagse bomen 2008-2017, kiezen voor kwaliteit en diversiteit. Den Haag: Gemeente Den Haag.
Baldewsingh, R. (2010). Waterplan Den Haag 2010-2015. Den Haag: Gemeente Amsterdam.
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Dienst Stedelijke Ontwikkeling. (2009). Woonvisie Den Haag 2009 tot 2020. Den Haag: Gemeente Den Haag.
Gemeente Den Haag. (2010). Energievisie Den Haag 2040. Gemeente Den Haag.
Ministerie van VWS. (2007). Nationaal Hitteplan 2007. Den Haag.
Norder, M. (2005). Structuurvisie Den Haag 2020. Den Haag: Gemeente Den Haag.
Smit, P. (2007). Actieplan luchtkwaliteit Den Haag 2007-2015. Den Haag: Gemeente Den Haag.
Smit, P. (2011). Haagse nota mobiliteit. Bewust kiezen, slim organiseren. Den Haag: Gemeente Den Haag.
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133 134 Acknowledgments
I would like to thank my mentors Dipl.ing. Alexander Wandl, msc. and Dr.ir Frank van der Hoeven for their supervision during my graduation.
Alex for pushing me to start writing even when my writing skills were called ‘colloquial.’ Frank for trying to develop a more critical stance towards my own work and the sources I used. The meetings were a fine mix of elaborating on new insights brought up by the studied matter and other projects and on the other hand efficient, though sometimes confusing feedback on the delivered work. Last, I want to thank you in particular for your support during times when my priorities were with my family.
Throughout the years I have met many amazing people within the faculty and on the outside. My colleagues, my fellow board members, and especially my friends are of great value for me and are my drive to set new goals. I would like to thank the people who have been with me for all these years; my girlfriend, my parents, my sister and my brother, my family and my friends and that they have kept up with all my stories, my ideas and my ambitions.
Cheers!
135 136 Appendices
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137 A1 - Neighborhoods and boroughs of The hague
Neighborhoods 1 Oostduinen 23 Willemspark 2 Belgische Park 24 Haagse Bos 3 Westbroekpark en Duttendeel 25 Marlot/ Mariahoeve 4 Benoordenhout 26 Bezuidenhout 5 Archipelbuurt 27 Stationsbuurt 6 Schevingsebosjes 28 Centrum 7 Scheveningen 29 Schildersbuurt 8 Duindorp 30 Transvaalkwartier 9 Geuzen- en Statenkwartier 31 Rustenburg en Oostbroek 10 Zorgvliet 32 Leyenburg 11 Duinoord 33 Bouwlust en Vrederust 12 Bomen- en bloemenbuurt 34 Morgenstond 13 Vogelwijk 35 Zuidepark 14 Bohemen en Meer en Bos 36 Moerwijk 15 Kijkduin en Ockenburgh 37 Groente- en Fruitmarkt 16 Kraayenstein en de Uithof 38 Laakkwartier en Spoorwijk 17 Loosduinen 39 Binckhorst 18 Waldeck 40 Wateringsveld 19 Vruchtenbuurt 41 Hoornwijk 20 Valkenboskwartier 42 Ypenburg 21 Regentessekwartier 43 Forepark 22 Zeeheldenkwartier 44 Leidschenveen
Boroughs 1 Loosduinen 5 Centrum (city core) 2 Escamp 6 Laak 3 Segbroek 7 Haagse Hout 4 Scheveningen 8 Ypenburg/ Leidscheveen
138 Apendices
Neighborhoods by number
1
2 7 3 4 6 9 8 5 25 10 24 23 11 13 22 26 12 28 21 20 27 14 29 19 39 31 30 43 18 44 32 15 37 38 35 17 41 36 34 42 16 33
40
0 0,5 1 2,5 5 km
Boroughs of The Hague
4.
7.
3. 5.
6. 8. 1.
2.
0 0,5 1 2,5 5 km
139 A2 - The Hague Vulnerability assessment
Neighbourhoods Critical factors Physical conditions Priority Green Building Liveability structure energy Number Nr. Name Heat Elderly (lack) (lack) label Density of points 2 Belgische park Ο Ο Ο Ο 4 7 Scheveningen Ο Ο Ο Ο Ο Ο Ο 7 9 Geuzen- en Ο Ο Ο Ο Ο Ο 6 Statenkwartier 12 Bomen- en Ο Ο Ο 3 Bloemenbuurt 20 Valkenboskwartier Ο Ο Ο Ο Ο Ο Ο Ο 8 21 Regentessekwartier Ο Ο Ο Ο Ο Ο Ο Ο 8 22 Zeeheldenkwartier Ο Ο Ο Ο Ο Ο 6 26 Bezuidenhout Ο Ο 2 27 Stationsbuurt Ο Ο Ο Ο Ο Ο 6 28 Centrum Ο Ο Ο Ο Ο Ο 6 29 Schildersbuurt Ο Ο Ο Ο Ο Ο Ο Ο Ο Ο Ο 11 30 Transvaalkwartier Ο Ο Ο Ο Ο Ο Ο Ο Ο Ο 10 31 Rustenburg en Ο Ο Ο Ο Ο Ο Ο Ο Ο 9 Oostbroek 37 Groente- en Fruitmarkt Ο Ο Ο Ο Ο Ο Ο Ο 8 38 Laakkwartier en Ο Ο Ο Ο Ο Ο 6 Spoorwijk 40 Wateringseveld Ο Ο 2 Industrial areas 17 Loosduinen Ο Ο Ο Ο Ο n.a. 5 39 Binckhorst Ο Ο Ο Ο n.a. 4 43 Forepark Ο Ο Ο Ο n.a. 4
140 Apendices
141
143 Synthesis; heat proof The Hague + dŚĞ,ĂŐƵĞϮϬϰϬ DƵŶŝĐŝƉĂůŝŶŝƟĂƚĞĚĂĐƟŽŶƐ Heat networks; Expansion of heat network adding green structure in renewed streets
Green structure; Renewal and restructuring of An integrated approach towards heat proof cities. neighborhoods
Climate change is one of the biggest challenges we face during this Development focus century; heatwaves, periods of extreme drought, and heavy rainfall + get more common. Increasing temperatures have massive impact on zones cities. High amounts of paved- and built-up surfaces store heat during 6. the day, making cities warmer than their rural environment. In order to keep our living environments healthy and save; many cities all over �enovation the world are developing climate adaptation strategies. In this scope The Hague is falling behind; the city lacks policy to Accessible water; effectively adapt to the changing climate conditions. This is alarming since The Hague suffers from a severe heat island. In order to effectively mitigate heat in The Hague; this thesis develops an integrated approach towards climate adaptation. Therefore spatial “Swimming Singels” policies get assessed on their climate goals and combined with
necessary measures to mitigate heat. The Hague 2040 Scheveningen/ Kijkduin The integrated strategy is developed by performing three strategy design studies on The Hague. The proposed actions are in accordance to the city’s spatial ambitions and focus on the city’s green structure, 'ƌĞĞŶǁŝƚŚĨƵŶĐƟŽŶƐ͖ spatial planning and demographic trends especially of the elderly. The synthesis of these three studies results in an integrated strategy, The Hague 2040+, that offers the municipality a set of key-actions the city Haagse Markt A can execute under existing policy to effectively mitigate urban heat.
Klaas Akkerman, July, 2015. 1. ŽŵŵƵŶŝĐĂƟŽŶ͖
Heatplan 3. 7.
2.A
4.
5. WĂƌƟĐŝƉĂƚŽƌŝĂůĂĐƟŽŶƐ 1. Wastelands 2.
‘Haagse tuintjes’
Green roofs and façades
Green industrial areas
džŝƐƟŶŐƐƚƌƵĐƚƵƌĞ
Forest and parks
Vliet and Singles 0 0,5 1 2,5 5 km