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1

Laboratory study of the effects of terrestrial coastal forests on the absorption of solitary wave force

Mirzakhani Golnaz, Ghanbari-Adivi Elham, Fattahi Rohollah

Acta Geophysica

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2024

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Vol. 72, no. 1

449--465

EN

One of the beach protection techniques is using natural methods based on the coastal ecosystem. Studies show the reducing effect of forest covers on wave destruction intensity in different areas. However, it is not yet well understood how various densities of terrestrial coastal forest (TCF) affect the wave attenuation and reduce their strength. Studying the impact of various forest parameters, such as density, distance, and arrangement type on the wave force attenuation, this research measures the wave forces directly. TCF model was installed in a knife edge flume, which equipped with a load cell and an acoustic Doppler velocimeter. The experiments were performed in two staggered and parallel arrangements consisting of different densities from 12 to 273 stems per unit area. Based on obtained results, TCF had significant effects on the wave force absorption. An increase in the number of trees (density) increased TCF resistance force and the absorbed wave force. In its best, the TCF could absorb the wave force 3.76 times more than the no-TCF case. It could reduce the wave height by up to 81% at the highest density and maximum wave height. The absorbed wave force and drag coefficient rose as the number of rows of trees opposing the flow decreased and the intervals between trees were shortened. Increasing tree density from 12 to 273 stems per unit area increased the drag coefficient by the average of 61.82% for parallel and staggered arrangements, which means an average increase of 9.7% for each TCF row.

2

The influence of hydro-climatological balances and Nature-based solutions (NBS) in the management of water resources

Gutry-Korycka Małgorzata

Meteorology Hydrology and Water Management. Research and Operational Applications

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2020

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Vol. 8, Iss. 1

4--27

EN

This article offers a historical review of (cognitive) scientific research that demonstrates the development of key concepts relating to balances in the hydrological and hydro-climatic cycles, thereby supplying a basis for quantitative and qualitative assessment of renewable water resources. The review reveals the direction knowledge took as it developed through successive cognitive and applied stages. The emphases are on how global and regional hydrological conditioning underpin integrated concepts for the management of water resources. The primary aim of this article is to describe the main achievements, approaches and scientific initiatives, along with their theoretical underpinnings, in the hope of encouraging application and further appreciation. Attention is thus paid to milestones along the road to global development, as manifested in the (at times abruptly changing) effort to better assess and understand the use of water resources in various economic, social and ecological activities. The aim is first and foremost to encourage the achievement of sustainable development as humankind’s main hope for the future. A further focus is on initiatives, scientific issues, and concepts that have been espoused by international organisations and illustrate the increasingly essential harmonious use of water resources at local, regional, continental, and planetary scales. Relevant global conferences have demonstrated wide readiness to adopt declarations, or to issue appeals and resolutions, in support of fuller assessment of renewable water resources. Examples of excessive use have been identified, and efforts have been made to counteract both floods and deficits, and hence avoid crises. These deliberations have also stimulated long-term forecasting, for periods up to 2030 or even 2050. Also stressed here are the challenges, inspirations, and achievements of pure and applied science when it comes assessing the risk that the Earth’s potential to supply water resources will be exceeded. The suitability of current assessments of water resources is evaluated, and reference made to ecologicallyintegrated answers such as Nature-based solutions (NBS), as backed by the UN and UNESCO (2018) in combination with principles set out in the EU’s Water Framework Directive (2000/60/EC).

3

Assessing Nature-Based and Classical Engineering Solutions for Flood-Risk Reduction in Urban Streams

Ourloglou Olga, Stefanidis Konstantinos, Dimitriou Elias

Journal of Ecological Engineering

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2020

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Vol. 21, nr 2

46--56

EN

Urbanization of stream ecosystems with the purpose of managing the flash-flood events is nowadays considered responsible for habitat loss and alteration of the natural flow regime with severe implications for the ecosystem functioning. Unsurprisingly, the river scientists have started seeking alternative options inspired from nature for mitigating the flood-risk and maintaining the stream at its natural state. With this article the authors demonstrate the effects of a nature-based solution (NBS) for managing an urban stream based on the use of bioengineering materials (e.g. plants) and the implementation of the actions that restore the stream to its natural form (e.g channel widening). The HEC-RAS software was employed to simulate the flow and hydraulic components of an approximately 800m long reach of an urban stream under three different scenarios of flood risk management with a design flow set to 400 m3/s. The first scenario was based on the current situation of the stream, the second scenario concerned the stream restoration by following the nature-based solutions, while the third scenario was based on the classical “grey” engineering approach of concrete channelization. Unmanned Aerial Vehicle (UAV) photogrammetry methods and the Pix4Dmapper software were used in order to develop a detailed 3D model of the studied reach that accurately captured the current geomorphology. The obtained results showed that with concrete channelization, the average and maximum flow of the stream increases significantly in relation to the current situation, from 2.48 and 4.88m/s to 9.82 and 11.22 m/s, respectively, while the average Froude number raises from 0.36 to 1.69 implying super-critical flows. In contrast, the NBS scenario retained lower flow velocities and average Froude number similar to those under the current conditions. In addition, a cost estimation analysis for both stream management techniques revealed that the NBS is much cheaper than the traditional channelization (1.1 mil € vs 5.6 mil €). In conclusion, our findings suggest that the future restoration of urban streams should consider the nature-based solutions since i) they can be effective with regard to the reduction of flood-risk, ii) are cheaper than the traditional “grey” techniques and, most importantly, iii) maintain the natural state of the ecosystem which improves not only the ecosystem functioning but also the aesthetic value within the urban context.

4

Znaczenie światła dziennego i jego dystrybucja w obiektach architektonicznych zaprojektowanych przez Victora Hortę

Widera Barbara

Architectus

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2020

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Nr 3 (63)

37--51

PL

W artykule przedstawiono wyniki badań nad rolą światła dziennego w wybranych budynkach reprezentatywnych dla twórczości Victora Horty. Przeprowadzono analizę porównawczą czterech obiektów zlokalizowanych w Brukseli: Hôtel Tassel, Hôtel van Eetvelde, Maison et Atelier Horta oraz Magasins Waucquez. W badaniach in situ uwzględniono analizy poziomu oświetlenia światłem dziennym w celu określenia współczynnika oświetlenia dziennego (daylight factor). Przeprowadzone badania wykazały, że światło dzienne było dla Horty jednym z podstawowych elementów kształtujących architekturę budynku, równie istotnym jak prawidłowo zaprojektowany układ funkcjonalno-przestrzenny czy system konstrukcyjny. Do najważniejszych założeń, definiujących rolę światła dziennego w budynkach projektowanych przez Hortę należały: dążenie do zapewnienia użytkownikom budynku kontaktu z przyrodą jako źródłem wszelkiego życia; wzorowane na obserwacji natury dążenie do wyeliminowania stref pozbawionych światła dziennego; dążenie do tworzenia otwartych, jasnych i dobrze wentylowanych przestrzeni, będących dla architekta wyznacznikiem funkcjonalności i elegancji. Wyodrębniono siedem głównych metod, za pomocą których architekt osiągał opisane powyżej cele. Były to: eksperymentalne zastosowanie stali i szkła w fasadach, świetlikach i witrażach; innowacyjne konstrukcje umożliwiające otwarcie przestrzeni i dystrybucję światła wewnątrz budynku; doprowadzanie światła dziennego do wszystkich pomieszczeń; wizualne łączenie wnętrza z zewnętrzem; wykorzystanie klatek schodowych do rozprowadzania światła i powietrza; stosowanie luster optycznie powiększających przestrzeń i odbijających światło oraz wprowadzanie materiałów o wysokiej luminancji i reflektancji. Analizy wykazały, że dzięki stosowaniu tych metod w badanych obiektach uzyskano bardzo wysoki poziom współczynnika oświetlenia dziennego. Najwyższy maksymalny stwierdzono w Magasins Waucquez (18,5%), przy czym średnia wartość współczynnika oświetlenia dziennego dla badanych obiektów przekroczyła 8%, a minimalny poziom w żadnym z budynków nie był niższy niż 2%. Przeprowadzone badania potwierdziły, że Horta jako jeden z pierwszych osiągnął tak znakomite efekty w zakresie oświetlenia dziennego budynków, będąc pod tym względem prekursorem najbardziej aktualnych tendencji w projektowaniu budynków komfortowych dla użytkownika i bezpiecznych dla środowiska naturalnego.

EN

The article presents the results of research on the role of daylight in selected buildings representative of the work of Victor Horta. A comparative analysis of four facilities located in Brussels was carried out, including: Hôtel Tassel, Hôtel van Eetvelde, Maison et Atelier Horta and Magasins Waucquez. In situ studies included analyses of the level of daylight illumination to determine the daylight factor. The research showed that for Horta daylighting was one of the basic elements shaping the architecture of the building, having the same importance as a properly designed functional and spatial layout or a structural system. The most significant assumptions defining the role of daylight in buildings designed by Horta were: the goal to provide the building users with contact with nature; the aspiration (inspired by nature) to illuminate all rooms in the building with daylight; the need to create open, bright and well ventilated spaces that were an indicator of functionality and elegance for the architect. Seven main methods, by which the architect achieved the objectives described above, were identified. These were: the experimental use of steel and glass in façades, skylights as well as in stained glass or lattice windows; innovative structures enabling the space opening and the light distribution inside the building; providing daylight to all rooms; visual connection of the interior with the outside; the use of staircases to distribute light and air; placing mirrors to enlarge the space and reflect light, and the introduction of materials with high luminance and reflectance. Analyses showed that due to the use of these methods in the tested buildings, a very high level of daylight factor (DF) was obtained. The highest maximum value of DF = 18.5% was achieved in Magasis Waucquez, while the average value of the daylight factor for the tested objects exceeded 8% and the minimum DF level in any of the buildings was not lower than 2%. The study confirmed that Horta was one of the first to achieve such excellent results in the field of building daylighting, being a precursor of the most current trends in the design of buildings comfortable for the users and safe for the environment.

5

Urban ecosystem services – assessment of potential at the different spatial scale: an example of Poznań

Zwierzchowska I.

Ekonomia i Środowisko

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2017

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nr 1

207--225

EN

The aim of the article is the mapping and assessment of ES potential in the scale of the city and identification of site-specific elements that support or reduce the ES potential at the site scale. For this purpose, a multi-criteria spatial analysis, mapping and field vision were conducted. The results showed urban areas with the lowest ES potential that are also characterized by the highest population density. At the site scale, land cover and land-use types with other anthropogenic elements that affect the ES potential and flow were identified. The results can be used to support the transformation process of the city toward nature-based solutions.