Student research results - Sustainable bike tunnel design

In a novel comparison, one of our BSc students used sustainable design of skyscrapers to rethink how bicycle tunnels in the Netherlands are constructed. Not only could this approach save money, but it can also determine how to save materials, use less concrete and thereby less emissions, or compare alternative materials. Different shapes of tunnels could allow for different weight distribution depending on the material types. You may assume this is already done automatically, and for standard designs this may be the case. However, for this case a partially open tunnel underneath a roundabout was designed, which is more common in a country like the Netherlands. Having an open roof changes the distribution of forces from a standard design. The link to the full thesis in the repository is here and the abstract can be found below.

  

Abstract

More and more bike tunnels are being developed in the Netherlands due to the rise in population numbers. Bike tunnels often provide safe road crossing for pedestrians and cyclists, promoting uninterrupted traffic flow. However, conventional bike tunnel designs are expensive and carbon-intensive due to the extensive use of overly designed concrete structures. Meanwhile, in the tall buildings sectors, many structural and sustainable innovations have been made. These innovations led to many modern buildings being created that are material efficient and climate resilient.

This research project started by investigating some of the most representative structural and sustainable developments in the recent decades. The follow-up of the investigation resulted in the creation of two structural design prototypes, specifically developed for a bike tunnel project in the Municipality of Ommen. The first prototype implements a topology optimization to structural members. The second prototype deploys a multi-functional centred V-brace system. Both of these prototypes had in focus two sustainable design elements: a composed concrete-timber floor and an open-air design. With the use of Dynamo, a parametric design automation program, the designs were modelled in Revit and transferred to Robot Structural Analysis for structural verification. While the first prototype is structurally not feasible, the second prototype successfully passes the Eurocode verification.

By using IBIS voor Infra and DuboCalc, prototype two is further evaluated for material costs and environmental impact. The evaluation returns a promising cost efficiency result and a significant reduction in environmental impact. The implementation of this type of multi-functional structural systems could sufficiently reduce structural material usage, when compared to conventional single-purposed structural systems. The results also suggest a 1+1>2 relationship between structural and sustainable optimization. While the first prototype is unfeasible, its modelling process sheds some light on how topology optimization could be realistically applied in practice.

Overall, this research project is proposing a promising structural system solution for future bike tunnels. At the same time, it provides insights on how project costs and environmental impact can be reduced by using parametric modelling automation during the design phase, and topology optimization in the manufacturing phase. This proposed approach can prove useful to future projects, and can further enrich the industry.

 

Student research results - vulnerability to flooding by extreme precipitation in Enschede

One of our BSc students recently graduated on this topic with a Dutch thesis by among others conducting interviews with various stakeholders, including municipality Enschede, waterboard Vechtstromen, Safety Region Utrecht, social worker of the waterlogged area Pathmos, and housing coorporation. To guarantee their annonimity, these interviews are not publicly plublished. The results however did show some interesting points. The main point was to find out if social factors are also taken into account when determining flood vulnerability, and not just construction or physical environment factors. Unsurprisingly, there is still some development possible there, as most stakeholders are not yet too familiar with social factors. The English abstract is below. 

"Abstract

One of the effects of climate change is that extreme weather events are expected to happen more
frequently. These heavy rainfall events are a risk to safety since they can result in floods. In July 2024,
floods occurred in the Pathmos neighborhood due to heavy rainfall. The “Onderzoeksraad voor
Veiligheid,” a Dutch research institute, published a report about this flood. One of its conclusions
was that the influence of social and constructional factors on the vulnerability to floods caused by
heavy rainfall was largely ignored in the current climate policy. As a result, it is unclear what factors
should be considered while determining the vulnerability to floods caused by heavy rainfall.
Therefore, a methodology is developed to identify and analyze the social and constructional factors
that influence vulnerability.
This research shows that the location has the most impact on the vulnerability to these floods.
Besides the location, the average age and diameter of the sewage influence vulnerability
significantly, together with the built environment, height of the doorstep, presence of installations
on/below ground level, and people with special needs. Also, the quality of the buildings, the
presence of social networks, and the socioeconomic status matter.
This shows that besides the location, social and constructional factors also influence the
vulnerability to floods caused by heavy rainfall. These results can be used as an addition to the
current policy on climate adaptation. Together with the current policy, which is mostly driven by the
physical characteristics of the flood, more precise decisions can be made on where to add climateadaptive
measures. Therefore, this research can help identify the most vulnerable areas within
Enschede. "

UT Field Lab installing internal sensors

We installed additional indoor sensors this month to gather information of the green roofs' impacts on the indoor climate. Now each of the office/storage spaces inside has data on temperature, humidity, and CO2. While we cannot show the entire rooms online, the placement shows the sensors have more or less the same height in each room.   

Though there is a very clear online guide as to how to connect the sensors to the main unit, both physically and virtually, there were still some hiccups. The main issue was that even though following the step by step guide and adding one sensor at a time, and renaming these to correspond to the room numbers, this information was lost in the process of connecting the phone app to the online dashboard where data can be downloaded. This meant that each sensor was simply registered as 'sensor' instead of also indicating what room it was in. Since these were all identical sensors, it would not be possible to deduce what room had which sensor and therefore which values corresponded to which room. 

Rather than starting the entire process from scratch, I opted a simpler determination by tricking the temperature sensor in showing a higher value, with my cup of tea. With these temporary spikes, each sensor could be renamed to the appropriate room, which took only 15 minutes. The last room of course required no more tea temperature spiking, only renaming.

Policy trends in river and flood management in the Netherlands since the 2010s - part 8 and final

This final part has an evaluation of the outcomes and limitations of the approaches and considers the topics of: water awareness of the general public (3), and the promise of green infrastructure (4). 

3)

When it comes to awareness of climate related risks and responsibilities, most citizens expect the government to solve everything for them and there is no culture of disaster awareness and mutual collaboration like in Japan, or even for individual preparation to survive 72 hours like on the US. Despite there now being campaigns to inform people of what to do and how to prepare, this is not taken up as a necessary action. The OECD Studies on Water, Water Governance in the Netherlands (2014)[i] summarizes this succinctly: “There is a striking “awareness gap” among Dutch citizens related to key water management functions, how they are performed and by whom. Similarly, the perception of water risks is low. Many people are not aware of the basics about evacuation policy, the origin of the water they drink or whether their property is built on a flood plain. This awareness gap is largely a result of a high level of trust in government and the successful avoidance of major flood disasters since 1953.” While there is consistent monitoring of this awareness, there is less of a concrete approach in how to change this awareness for the better.

 

Climate awareness item	2015	2016	2020	2024
People concerned about climate change	62%	67%
People concerned about a large regional flood	23%	30%	23-25%
People who expect pluvial flood in the coming 10 years				67%
People who have an evacuation package ready				9%
People who have more vegetation than tiles in their garden				54%

Table: Results from water awareness monitoring[ii],[iii], [iv]

 

This is also the case for other climate related hazards. The KNMI has already begun changing its heat warnings to more understandable language and actions[v], and there are maps available that visualize the linkage between heat stress and potentially vulnerable older adults[vi]. The drawback is that research has shown that mere information campaigns are insufficient and the perceptions people have regarding climate change should be targeted[vii]. This leaves not just a knowledge gap, but also a chance to enhance understanding and support for the finances and resources necessary to prepare for water related disasters among the general public, especially when it comes to what people can do in their own yard.

 

4)

A major policy trend in addressing climate change impacts has been greening the urban landscapes. Especially the inner cities have faced decades, if not hundreds of years, of construction above and below ground for infrastructure and services, resulting in large areas of impermeable pavement. Urban planners are eager to respond with green and blue transformations in the form of trees, retention areas, green walls and roofs, etc. that get most attention of their potential benefits, both for climate adaptation and beyond. While it is true that vegetation can help reduce local flood peaks, evaporate moisture up to 70%, and reduce temperatures, the exact amounts are often left vague, by both policy ambitions and quantifiable research results. The amount of irrigation required for vegetation to optimally function and provide these benefits is often also glossed over. As an overall beneficial impact appears to remain, the next question centers on species. The local Dutch climate is expected to shift the coming decades from an oceanic climate to include a humid subtropical climate.

There are guides available for urban planners that indicate which species are more resilient for certain types of climate stress[viii], [ix]. Still, this means that any urban vegetation planted to help adapt to climate change must be started to be grown in plant nurseries imminently, which brings with it the need for long term panning and investments spatially, species wise. The biggest challenge on the urban scale is that 50-70% of the inner urban areas are privately owned, meaning another awareness campaign and subsidy measures could have a large impact on how citizens can contribute to locally reducing negative climate change impacts.

 

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[i] https://www.oecd.org/en/publications/water-governance-in-the-netherlands_9789264102637-en.html#page1

[ii] https://klimaatadaptatienederland.nl/publish/pages/163262/ons_water_onderzoeksresultaten_waterpeil_2017_wateroverlast-waterkwaliteit.pdf

[iii] https://klimaatadaptatienederland.nl/publish/pages/235211/34043-waterpeil-2024-rapportage-herziene-versie.pdf

[iv] https://www.hdsr.nl/publish/pages/103753/definitief_rapport_waterbewustzijn_240120.pdf

[v] https://www.knmi.nl/over-het-knmi/nieuws/de-ene-soort-hitte-is-de-andere-niet-daarom-is-er-nu-hittekracht

[vi] https://klimaatadaptatienederland.nl/actueel/actueel/nieuws/2020/hitte-eenzaamheidskaart/

[vii] https://www.nature.com/articles/s41558-018-0371-y

[viii] https://bomentabel.nl/

[ix] https://bootendart.nl/toepassingen/#Klimaatbestendig

 

Extinction of Experience - part 1

As we write our paper on the walk-shops we have held at the UT, extinction of experience is a topic we need to address, as we hope to counter it through means of the walk-shops. Or at the very least, address it. 

The loss or extinction of experience refers to the decrease of human interaction with nature, and is connected to the loss or extinction of knowledge of nature.

Several studies point out that reduced experiences in with nature have negative effects. These include reduced health and well-being, and reduced desire to support biodiversity or conservation actions and policies (Gaston and Soga, 2019[1]). To understand the extent of this problem, it is important to distinguish what we mean with these terms when we try to define or measure its extent.

For this we need to describe what we mean with nature, interactions, extinction, and how a changing human experience over a lifetime can be measured validly.

For the first term, Gaston and Soga (2019) state that nature is often described as wild, ‘free from human interventions such as cultivation or domestication. This would leave nearly entire countries in coastal areas as unnatural. For instance, the global map “Last of the Wild” shows the areas in the world where the Human Footprint Index is 10 or less (Gassert 2023[2]) https://www.frontiersin.org/journals/remote-sensing/articles/10.3389/frsen.2023.1130896/full), and it does not leave many areas in the urbanized parts of the world to experience wilderness. Then again, if there were humans to experience the wilderness, the footprint would increase and they wouldn’t be considered as wild anymore. It would also mean that all forms of green infrastructure do not count as nature experience. Gaston and Soga recommend a wider range of the term nature to include cultivated and domesticated species. There is also evidence that these forms of nature also bring about the desired benefits, so why not include more ‘unwild’ forms of nature.

For the second term, interactions, Gaston and Soga state that the debate is about what counts as an interactions, when these are direct or indirect. This is at best a vague scale. For instance: animals, plants, or even weather effects could interact with our bodies or senses directly, we could observe these in our direct vicinity, we could observe these through a window, or we could look at depictions on a screen or painting etc.. It has already been found that patients recovering in hospitals who observe nature, real or ‘fake’, recover slightly faster than those who don’t (Guidolin, 2024[3]). Again, here it appears prudent to include options, but indeed to be clear about what is included. It is also linked to a further term where they distinguish between interactions and experiences. Merely interacting, but not having any reflection or follow-up emotional, spiritual, or intellectual experience is stated to also need a distinction. This I think raises a myriad of questions. If you dream of nature, was it due to a nature interaction? It is less feasible to draw such a distinction as experiences can and most often are more private and immeasurable than interactions. Experiences could be self-reported by participants if answering the research question would be strengthened by it.

The third term of extinction is also on a type of scale. When is experience truly lost (and can be regained), when extinct (impossible to regain)? Gaston and Soga include people who live in highly urbanized areas (thus excluding the less wild versions of nature), house- or bed-bound people (again excluding less wild versions and images of nature), and people who are not particularly eager to interact with nature. Perhaps here extinction is too strong of a word and while knowledge can be regained, on average, for most people, so can experience.

In alignment with Gaston and Soga's call to be more specific (2019), the type of walk-shops we have organized mainly focus on countering the loss of experiences with living organisms.

 

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[1]Gaston KJ, Soga M. Extinction of experience: The need to be more specific. People Nat. 2020; 2: 575–581. https://doi.org/10.1002/pan3.10118

[2] Gassert F, Venter O, Watson JEM, Brumby SP, Mazzariello JC, Atkinson SC and Hyde S (2023) An operational approach to near real time global high resolution mapping of the terrestrial Human Footprint. Front. Remote Sens. 4:1130896. doi: 10.3389/frsen.2023.1130896 https://www.frontiersin.org/journals/remote-sensing/articles/10.3389/frsen.2023.1130896/full

[3] Guidolin K, Jung F, Hunter S, et al. The Influence of Exposure to Nature on Inpatient Hospital Stays: A Scoping Review. HERD: Health Environments Research & Design Journal. 2024;17(2):360-375. doi:10.1177/19375867231221559