Hoe schoon is de lucht in Nederland, in Amsterdam en in de buurt? In deze workshop van het RIVM ga je aan de slag met data over luchtverontreiniging door fijnstof, stikstof en koolstofdioxide. Wat betekenen deze data, hoe zoek je ze op en wat kun je ermee doen?
This is the 12th episode of a series 25 building blocks to create better streets, neighbourhoods, and cities. This post deals with the question of how nature itself can help to deal with excessive rainfall and subsequently flooding of brooks and rivers, although these disasters are partially human-made.
Until now, flooding has mainly been combated with technical measures such as the construction of dykes and dams. There are many disadvantages associated with this approach and its effectiveness decreases. Nature-inclusive measures, on the other hand, are on the rise. The Netherlands is at the forefront of creating space for rivers to flood, where this is possible without too many problems.
An important principle is to retain water before it ends up in rivers, canals, and sewers. The so-called sponge city approach can be incorporated into the fabric of new neighbourhoods and it creates sustainable, attractive places too. A combination of small and large parks, green roofs, wadis, but also private gardens will increase the water storage capacity and prevents the sewer system from becoming overloaded and flooding streets and houses. Steps are being taken in many places in the world; [China is leading the way](https://www\.dropbox\.com/s/47zxvl3kgbeeasa/Tale of two cities.pdf?dl=0) (photo top right). However, the intensity of the precipitation is increasing. In 2023, 75 cm of rain fell in Beijing in a few days. Under such conditions, local measures fall short. Instead, nature-inclusive measures must be applied throughout the river basin.
In new housing estates, water basins are constructed to collect a lot of water. Their stepped slopes make them pleasant places to stay in times of normal water level. The pictures on the left are from Freiburg (above) and Stockholm (below). The top center photo shows the construction of a retention basin in Lois Angeles.
Wadis
Wadis are artificial small-scale streams in a green bed with a high water-absorbing capacity. In the event of heavy rainfall, they collect, retain and discharge considerably more water than the sewer system (bottom center photo). Green strips, for example between sidewalks, cycle paths and roads also serve this purpose (photo bottom right: climate-adaptive streets in Arnhem).
Green roofs look good, they absorb a lot of CO2 and retain water. The stone-covered urban environment is reducing the water-retaining capacity of the soil. Sufficiently large interspaces between paving stones, filled with crushed stone, ensure better permeability of streets and sidewalks. The same applies to half-open paving stones in parking lots.
Up to the present day, flood-prone parts of cities are used for various purposes, often because the risk is underestimated or the pressure on space is very great. London's Housing and Climate Crises are on a Collision Course is the eloquent title of an article about the rapidly growing risk of flooding in London.
Hackney Wick is one of 32 growth centers set to help alleviate London's chronic housing shortage, which has already been repeatedly flooded by heavy rainfall. However, the construction of new homes continues. Measures to limit the flood damage at ground floor level include tiled walls and floors, water-inhibiting steel exterior doors, aluminum interior doors, kitchen appliances at chest height, closable sewers, and power supply at roof-level. Instead, floating neighbourhoods should be considered.
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This is the 11th episode of a series 25 building blocks to create better streets, neighbourhoods, and cities. In this post, I wonder whether nature itself can tackle the environmental problems that humans have caused.
According to environmental scientists, ecosystems are providers of services. They are divided into production services (such as clean drinking water, wood, and biomass), regulating services (such as pollination, soil fertility, water storage, cooling, and stress reduction) and cultural services (such as recreation, and natural beauty). In case of nature-inclusive solutions ecosystems are co-managed to restore the quality of life on the earth in the short term and to maintain it in the long term, insofar as that is still possible.
The meaning of urban green can best be seen in conjunction with that of water, hence the term green-blue infrastructure. Its importance is at least fourfold: (1) it is the source of all life, (2) it contributes substantially to the capture and storage of CO2, (3) 'green' has a positive impact on well-being and health; (4) it improves water management. This post is mainly about the third aspect. The fourth will be discussed in the next post. 'Green' has many forms, from sidewalk gardens to trees in the street or vegetated facades to small and large parks (see collage above).
Trees and plants help to filter the water itself. They have a significant role to play in managing water and air pollution. Conifers capture particulate matter. However, the extent to which this occurs is less than is necessary to have a significant impact on health. Particulate matter contributes to a wide range of ailments. Like infections of the respiratory system and cardiovascular disease, but also cancer and possibly diabetes.
Heat stress arises because of high temperature and humidity. The wind speed and the radiation temperature also play a role. When the crowns of trees cover 20% of the surface of an area, the air temperature decreases by 0.3oC during the day. However, this relatively small decrease already leads to a 10% reduction in deaths. Often 40% crown area over a larger area is considered as an optimum.
According to Arbo Nederland, 21% of the number of absenteeism days is stress-related, which means approximately a €3 billion damage. A short-term effect of contact with nature on stress, concentration and internal tranquility has been conclusively demonstrated. The impact of distributing greenery within the residential environment is larger than a concentrated facility, such as a park, has.
The total amount of greenery in and around the house influences the nature and quantity of the bacteria present. This green would have a positive effect on the intestinal flora of those who are in its vicinity and therefore also on their immune function. The empirical support for this mechanism is still rather limited.
The impact of physical activity on health has been widely demonstrated. The Health Council therefore advises adults to exercise at least 2½ hours a week. The presence of a green area of at least ¼ hectare at 300 meters from the home is resulting more physical activity of adults in such areas, but not to more activity as a whole.
Well-designed green areas near the living environment invite social contacts. For instance, placement of benches, overview of the surroundings and absence of traffic noise. The state of maintenance are important: people tend to avoid neglected and polluted areas of public space, no matter how green.
Vegetation dampens noise to some extent, but it is more important that residents of houses with a green environment experience noise as less of a nuisance. It is assumed that this is due to a mechanism already discussed, namely the improvement of stress resistance because of the greenery present.
For years buildings made people sic. A growing number of architects want to enhance the effect of 'green' on human health by integrating it into the design of houses and buildings and the materials used. This is the case if it is ensured that trees and plants can be observed permanently. But also, analogies with natural forms in the design of a building
The 'Zandkasteel', the former headquarters of the Nederlandse Middenstandsbank in Amsterdam, designed by the architects Ton Alberts and Max van Huut, is organically designed both inside and outside, inspired by the anthroposophical ideas of Rudolf Steiner. The (internal) water features are storage for rainwater and the climate control is completely natural. The building has been repurposed for apartments, offices and restaurants.
Worldwide, there is a direct correlation between the amount of greenery in a neighborhood and the income of its residents. Conversely, we see that poorer neighborhoods where new green elements are added fall victim to green gentrification over time and that wealthier housing seekers displace the original residents.
The challenge facing city councils is to develop green and fair districts where gentrification is halted and where poorer residents can stay. Greening in poor communities must therefore be accompanied by measures that respect the residential rights and aim at improving the socio-economic position of the residents.
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Most important causes of death worldwide (Source: The Lancelet, le Monde)
This is the 10th episode of a series 25 building blocks to create better streets, neighbourhoods, and cities. In this post, I mainly focus on health problems which are directly related to the quality of the living environment
According to the WHO's Global Burden of Diseases Study, 4.2 million deaths worldwide each year are caused by particulate matter. The regional differences are significant. Urban health depends on the part of the world and the part of the city where you are living. More than 26 million people in the United States have asthma and breathing problems as a result. African-American residents in the US die of asthma three times as often as whites. They live in segregated communities with poor housing, close to heavy industry, transportation centers and other sources of air pollution.
Globally, the increasing prosperity of city dwellers is causing more and more lifestyle-related health problems. Heart disease, and violence (often drug-related) has overtaken infectious diseases as the first cause of death in wealthy parts of the world.
Very recently, Arcadis published a report on 'the healthy city'. This report compares 20 Dutch cities based on many criteria, divided over five domains. The four major cities score negatively on many aspects. In particular: healthy outdoor space, greenery, air quality, noise nuisance, heat stress and safety. Medium-sized cities such as Groningen, Emmen, Almere, Amersfoort, Nijmegen, and Apeldoorn, on the other hand, are among the healthiest cities.
In Amsterdam, the level of particulate matter and nitrogen dioxide (NO2) in 2018 exceeded World Health Organization standards in many streets. The GGD of Amsterdam estimates that 4.5% of the loss of healthy years is the result of exposure to dirty air.
In various cities, groups of concerned citizens have started measuring the quality of the air themselves. A professional example is the AiREAS project in Eindhoven. An innovative measuring system has been developed together with knowledge institutions and the government. Sensors are distributed over the area of the city and the system provides real-time information. The AiREAS group regularly discusses the results with other citizens and with the city government. The measurement of the quality of the air is supplemented by medical examination. This research has confirmed that citizens in the vicinity of the main roads and the airport have an increased risk of mortality, reduced lung function and asthma.
The AiREAS project is linked to similar initiatives in other European cities. Occasionally the data is exchanged. That resulted in, among other things, this shocking video.
Could the future not be that we are busy doing the obvious things for our health, such as walking, cycling, eating good food and having fun and that thanks to wearables, symptoms of diseases are watched early and permanently in the background, without us being aware of it? The local health center will monitor and analyze the data of all patients using artificial intelligence and advise to consult the doctor if necessary. An easily accessible health center in one's own neighborhood remains indispensable.
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