Recent research has indicated an increase in the likelihood and impact of tree failure. The potential for trees to fail relates to various biomechanical and physical factors. Strikingly, there seems to be an absence of tree risk assessment methods supported by observations, despite an increasing availability of variables and parameters measured by scientists, arborists and practitioners. Current urban tree risk assessments vary due to differences in experience, training, and personal opinions of assessors. This stresses the need for a more objective method to assess the hazardousness of urban trees. The aim of this study is to provide an overview of factors that influence tree failure including stem failure, root failure and branch failure. A systematic literature review according to the PRISMA guidelines has been performed in databases, supported by backward referencing: 161 articles were reviewed revealing 142 different factors which influenced tree failure. A meta-analysis of effect sizes and p-values was executed on those factors which were associated directly with any type of tree failure. Bayes Factor was calculated to assess the likelihood that the selected factors appear in case of tree failure. Publication bias was analysed visually by funnel plots and results by regression tests. The results provide evidence that the factors Height and Stem weight positively relate to stem failure, followed by Age, DBH, DBH squared times H, and Cubed DBH (DBH3) and Tree weight. Stem weight and Tree weight were found to relate positively to root failure. For branch failure no relating factors were found. We recommend that arborists collect further data on these factors. From this review it can further be concluded that there is no commonly shared understanding, model or function available that considers all factors which can explain the different types of tree failure. This complicates risk estimations that include the failure potential of urban trees.
MULTIFILE
The adaptation of urbanised areas to climate change is currently one of the key challenges in the domain of urban policy. The diversity of environmental determinants requires the formulation of individual plans dedicated to the most significant local issues. This article serves as a methodic proposition for the stage of retrieving data (with the PESTEL and the Delphi method), systemic diagnosis (evaluation of risk and susceptibility), prognosis (goal trees, goal intensity map) and the formulation of urban adaptation plans. The suggested solution complies with the Polish guidelines for establishing adaptation plans. The proposed methodological approach guarantees the participation of various groups of stakeholders in the process of working on urban adaptation plans, which is in accordance with the current tendencies to strengthen the role of public participation in spatial management. https://doi.org/10.12911/22998993/81658
MULTIFILE
With the rise of chronic diseases as the number one cause of death and disability among urban populations, it has become increasingly important to design for healthy environments. There is, however, a lack of interdisciplinary approaches and solutions to improve health and well-being through urban planning and design. This case study offers an HCI solution and approach to design for healthy urban structures and dynamics in existing neighborhoods. We discuss the design process and design of ROOT, an interactive lighting system that aims to stimulate walking and running through supportive, collaborative and social interaction.
DOCUMENT
Due to climate change, rising temperatures lead to more extreme heat stress in urban areas. Last summer, there were poignant images of people looking for shade in cities. Trees are effective measures to provide shade and decrease the perceived temperature. However, trees cannot grow in healthy conditions due to the conflicting interests of the many functions and infrastructure in cities. Also time is a limiting factor; before trees are fully grown and can fulfil its various functions (shade, biodiversity, appearance), it takes not only physical space but also time. Alternative interventions, such as a pergola, can help increase urban resilience by reducing the negative impacts of climate change.Pergolas are known, for example, in more southern Europe cities. However, despite the described promising effects of the pergola in documents to reduce heat stress and provide shade, we barely see these structures in the Dutch public space. We all know the pergola as an esthetical piece in the backyard where it provides shade, privacy and contributes to well-being, but they are not widely used in the public realm.Next to that, there are few or no known preconditions for an urban pergola. The functions that an urban pergola can offer go beyond providing shade. The pergola might help reduce noise and pollution, provide a meeting place in a neighbourhood and support biodiversity. Since space is scarce in cities where many different interests come together, we want to explore the potential contribution of an urban pergola to different problems. Therefore, at the Amsterdam University of Applied Sciences, we have worked on an urban pergola as a real 'boundary object' where we bring education, research, municipalities, and entrepreneurs across disciplines and sectors together to discuss the potential of such an object.For this workshop, we would like to show our first results of this interdisciplinary action research and continue answering the question: how can a pergola fit in the Dutch urban area? Therefore, we would like to explore the functions and forms of the urban pergola with stakeholders, such as municipalities, entrepreneurs, citizens, students, and researchers all from different disciplines. The desired outcome of this workshop is a joint proposal for implementing urban pergolas that can meet the versatile needs of cities and thereby make cities more liveable.
MULTIFILE
Risk assessments on trees in urban areas and roadside plantings have become common practice and a large body of information exists on qualitative aspects on the risks of tree failure. Quantitative analysis of financial damage due to tree failure is generally lacking. The objective of this paper is to determine the amount of tree failure related property damage and to derive possible trends in the number of cases and monetary claims and compensations. This paper presents the analysis of 1610 observations on urban tree failure in the Netherlands. The data originate from two different sources, i.e. jurisprudence (4% of the data) and 21 municipalities (96%). The data covers property damage in urban areas between the early sixties and 2010. Within municipalities, paid compensations due to tree failure are found to range from €0 to € 49,296 with an average of €2,244 per paid compensation. Results demonstrate a significant annual increase in tree failure as well as in paid compensations.
MULTIFILE
Small urban water bodies, like ponds or canals, are often assumed to cool their surroundings during hot periods, when water bodies remain cooler than air during daytime. However, during the night they may be warmer. Sufficient fetch is required for thermal effects to reach a height of 1–2 m, relevant for humans. In the ‘Really cooling water bodies in cities’ (REALCOOL) project thermal effects of typical Dutch urban water bodies were explored, using ENVI-met 4.1.3. This model version enables users to specify intensity of turbulent mixing and light absorption of the water, offering improved water temperature simulations. Local thermal effects near individual water bodies were assessed as differences in air temperature and Physiological Equivalent Temperature (PET). The simulations suggest that local thermal effects of small water bodies can be considered negligible in design practice. Afternoon air temperatures in surrounding spaces were reduced by typically 0.2 °C and the maximum cooling effect was 0.6 °C. Typical PET reduction was 0.6 °C, with a maximum of 1.9 °C. Night-time warming effects are even smaller. However, the immediate surroundings of small water bodies can become cooler by means of shading from trees, fountains or water mists, and natural ventilation. Such interventions induce favorable changes in daytime PET.
DOCUMENT
Since it is insufficiently clear to urban planners in the Netherlands to what extent design measures can reduce heat stress and which urban spaces are most comfortable, this study evaluates the impact of shading, urban water, and urban green on the thermal comfort of urban spaces during hot summer afternoons. The methods used include field surveys, meteorological measurements, and assessment of the PET (physiological equivalent temperature). In total, 21 locations in Amsterdam (shaded and sunny locations in parks, streets, squares, and near water bodies) were investigated. Measurements show a reduction in PET of 12 to 22 °C in spaces shaded by trees and buildings compared to sunlit areas, while water bodies and grass reduce the PET up to 4 °C maximum compared to impervious areas. Differences in air temperature between the locations are generally small and it is concluded that shading, water and grass reduce the air temperature by roughly 1 °C. The surveys (n = 1928) indicate that especially shaded areas are perceived cooler and more comfortable than sunlit locations, whereas urban spaces near water or green spaces (grass) were not perceived as cooler or thermally more comfortable. The results of this study highlight the importance of shading in urban design to reduce heat stress. The paper also discusses the differences between meteorological observations and field surveys for planning and designing cool and comfortable urban spaces. Meteorological measurements provide measurable quantities which are especially useful for setting or meeting target values or guidelines in reducing urban heat in practice.
DOCUMENT
This article will explore the Cradle to Cradle (C2C) framework for urban environments, focusing on the perception, utilization and maintenance of parks. The case study explores the perception of urban flora and the value of greenery in everyday life in The Netherlands. The reflection section addresses the difference between conventional and C2C approaches to greenery on the one hand and current green management policies and public opinion on the other hand. The author reflects on how urban planning policies can be better geared towards public awareness of C2C, and towards the implementation of ecologically benign management of urban flora. It is proposed that an implementation of urban green management consistent with C2C is feasible and desirable. It is feasible given the favorable shifts in public opinion in relation to urban sustainability, and it is desirable due to the basic cost-benefit analysis and increased need for urban sustainability. This is a post-peer-review, pre-copyedit version of an article published in Urban Ecosystems. The final authenticated version is available online at: https://doi.org/10.1007/s11252-015-0468-2 https://www.linkedin.com/in/helenkopnina/
MULTIFILE
Nature in cities serves a multitude of purposes, one of which is that it provides citizens opportunities to recover from stressful daily urban life. Such stress recovering effects of nature can be experienced through urban green, which in urban planning and design contexts can be divided into large natural areas - urban green space - and small scale elements in urban streets: the urban greenscape. The current study aims at finding the extent to which various small scale natural elements in residential streets and their possible configurations influence citizens' preferences for those streets. The research was conducted through an online survey in four cities in the Netherlands (n = 4,956). It used stated choice methods in a virtual environment street design. The method yielded high quality data, indicating that the use of virtual environments and imagery is suitable for stated choice research in the built environment. The results show that especially trees very strongly influence preference, indicating they deserve more attention and space in cities. Grass, which is typically favored by local governments, and vertical green have the smallest effects in residential streets. Furthermore, the concept of greenscape intensity is introduced as the intensities of both the element and the configuration were found to be highly relevant. The results clearly show that the higher either of these intensities, the more likely a respondent will prefer the greenscape design. Furthermore, low intensity on the one can be compensated by high intensity on the other. With these results, urban design professionals and local governments can better trade-off the different aspects of costs versus positive effects of urban greenscape designs.
MULTIFILE
In human-controlled environments, areas of wild plants are 'translated' into cultivated landscapes to accommodate social, cultural and economic needs. This article explores indoor, agricultural and (sub)urban landscape in the Netherlands, focusing on the use of plants both indoors and outdoors, and reveals anthropocentric, instrumental and unsustainable practices. The article also presents suggestions for alternative, more ethical and sustainable ways of relating to plants in the Netherlands and beyond. https://www.ecologicalcitizen.net/article.php?t=wilderness-plastic-plants-how-might-get-back-wildness https://www.linkedin.com/in/helenkopnina/
MULTIFILE
