Man-made Structures Research Articles

Aluminium surface work hardening enables multi-scale 3D lithography.

Multi-scale structures are ubiquitous in biological systems. However, manufacturing man-made structures with controllable features spanning multiple length scales, particularly down to nanoscale features, is very challenging, which seriously impacts their collective properties. Here we introduce an aluminium-based three-dimensional lithography that combines sequential nano-micro-macro-imprinting and anodization of multi-scale anodic aluminium oxide templates to manufacture well-defined multi-scale structures, using various materials. The high-fidelity nano-patterns and micro-patterns were facilitated by the surface work hardening phenomenon, where the nano-patterns can be further fine-tailored by anodization to have high-aspect-ratio and tunable nano-holes. Based on the aluminium-based three-dimensional lithography, multi-scale materials across length scales of at least 107 orders of magnitude were precisely fabricated, including carbon, semiconductors and metals. We integrated pressure sensors and biosensors with superior and customizable performances by tailoring the multi-scale carbon networks on different length scales from nanofibres and micropyramids to macrodome arrays. This work provides a versatile technique for prototyping on-demand multi-scale structures and materials to explore desirable mechanical and physical properties.

Joint Sensing and Communications in Unmanned-Aerial-Vehicle-Assisted Systems

The application of joint sensing and communications (JSACs) technology in air–ground networks, which include unmanned aerial vehicles (UAVs), offers unique opportunities for improving both sensing and communication performances. However, this type of network is also sensitive to the peculiar characteristics of the aerial communications environment, which include shadowing and scattering caused by man-made structures. This paper investigates an aerial JSAC network and proposes a UAV-selection strategy that is shown to improve the communication performance. We first derive analytical expressions for the received signal-to-interference ratio for both communication and sensing functions. These expressions are then used to analyze the outage and coverage probability of the communication part, as well as the ergodic radar estimation information rate and the detection probability of the sensing part. Moreover, a performance trade-off is investigated under the assumption of a total bandwidth constraint. Various numerical evaluated results have been presented complemented by equivalent simulated ones. These results reveal the applicability of the proposed analysis, as well as the impact of shadowing and multipath fading severity, and interference on the system’s performance.

Measuring and modelling directional effects in the frame of TIRAMISU (Thermal InfraRed Anisotropy Measurements in India and Southern eUrope)

Abstract. TRISHNA (Thermal infraRed Imaging Satellite for High-Resolution Natural resource Assessment) is a cross-purpose thermal infrared (TIR) Earth Observation (EO) mission designed to deliver images at high spatial (60 m) and temporal (3 days) resolutions. Its launch is foreseen in 2026 with a nominal mission duration of 5 years. This Indo-French polar-orbiting mission will overcome the limitations of thermal-optical observations from Landsat series and ASTER: low revisit, morning observations. TRISHNA scenes will be fully harnessed to pioneer the first cutting-edge high-resolution global maps of the land surface temperature (LST) and land surface emissivity (LSE) of natural and managed agroecosystems, man-made structures, water bodies, bare soils, rocks, snow, ice and sea. The quality of the preprocessing (radiometric calibration, atmospheric and directional corrections) is mandatory to satisfy the specifications with an expected precision of 1 K on LST in order to meet the targeted objectives. For such, it will be necessary to correct LST from directional effects with emphasis on the hot spot effect that can have an impact on LST up to several K. This is the goal of the TIRAMISU project to analyze TIR multiangular signatures over various biomes thanks to a pivoting system of cameras and a multi-model approach (1D, 3D, paramaterization). The modeling tools include 3 categories of models: SCOPE 1D, DART 3D and parametric BRDF models that are computationally efficient to perform inversion at global scale.

The Complex Nature of Ecotourist Experience and its Relationship with Pro-Environmental behavior in a National Park

Background and objective: Despite the increase in the number of studies related to visitor experiences and behavior in ecotourism and outdoor recreation settings, little empirical research has concentrated on how to identify the nature of ecotourists’ experiences within national park settings. Thus, the purpose of this study was to explore the complex nature of ecotourists’ experiences through personal, social, and environmental conditions, and to examine its relationship with pro-environmental behavior in natural environmental settings.Methods: For visitors, a questionnaire survey was administered to 396 adults who visited a national park in South Korea. Cronbach’s alpha coefficient scores were assessed to examine the reliability of ecotourist experiences. The confirmatory factor analysis (CFA) was utilized to explore the construct validity of the factor structure in the measurement variables. Pearson’s correlation coefficients were analyzed to examine the relationships between independent variables. Path analysis was used to examine the contributions of ecotourist experiences to satisfaction and pro-environmental behavior.Results: One of the most important findings is that ecotourist experiences scale shows relatively acceptable measurement properties and reasonable levels of fit. The results in the path model represented that ecotourist satisfaction had large effects on pro-environmental behavior. Based on the fit statistics in the proposed model, the relationship between the measurement variables provides a relatively good fit to the data and verify the convergent validity of the measures. Personal factor of ecotourist experience had significant effects on satisfaction. Additionally, satisfaction had a significant effect on pro-environmental behavior for ecotourists.Conclusion: The findings of the study provide empirical evidence that three dimensions of ecotourist experiences were significantly related to pro-environmental behavior through visitor satisfaction in natural environmental settings. Further study may need to explore the nature of visitor experience and its relationship with behavior of man-made structures in different settings.

Biodiversity assessment of the Lower Mekong Basin: evolutionary novelties in gemmular morphotraits of Genus Corvospongilla (Porifera: Spongillida) with description of a new species from Khorat Plateau, and biogeographic notes

A new occurrence of the genus Corvospongilla (Porifera: Demospongiae) is recorded from the Southeast Asia freshwater of Khorat Plateau, northeast Thailand. This is the second record of the genus from the Lower Mekong Basin with the discovery the new species Corvospongilla lampaoensis sp. nov. inhabiting a eutrophic lentic habitat (in Lam Pao Reservoir) on manmade structures of fish farming and fishery. Skeleton and gemmules morphotraits, diagnostic for Genus Corvospongilla of the family Spongillidae (Order Spongillida), were examined by Light and Scanning Electron Microscopy differentiating a new species from its twenty congeners known worldwide. In addition, the comparative morpho-analysis highlighted distant sympatric lineages with a notable morphotraits divergence of Corvospongilla lampaoensis sp. nov. vs Corvospongilla siamensis in two western tributaries of the Lower Mekong. The results from this study expand our knowledge of the order Spongillida adaptive radiation in Asia and fill a gap in the geographic range of the genus Corvospongilla in the Oriental-Indomalayan Region.

Enormous headward and gully erosion in a floodplain area reclaimed for open-cast lignite mining during the July 2021 flood in the Inde River valley (Western Germany)

BackgroundThe July flood 2021 at the mountain front of the Eifel-Ardennes Mountains and their foreland resulted in the flooding of the lignite mining area of Inden in Germany. The mining activities resulted in large-scale anthropogenic changes to the relief and fluvial system, leading to a landscape that is no longer adjusted to the recent process-response system. This paper concentrates on the Inde River, where lignite mining led to the relocation of a 5-km-long river section. The flood event resulted in the temporary avulsion of the Inde River into the former channel and, ultimately, in the flooding of the open-cast lignite mine Inden.ResultsThe flooding of the open-cast lignite mine Inden led to headwall erosion and enormous sediment mobilisation, mobilising more than half a million cubic metres of sediment within a few hours, forming a 700-m-long deeply incised channel cut. Thereby, the underlying bedrock, near-subsurface man-made structures, and former river channels influence the erosional processes to different degrees. Surface erosion is likely to be the decisive process, and subsurface erosion is likely to play a secondary role. In both cases, former channels and mill ditches were likely impacting the course of erosional processes.ConclusionsDuring high flood events open-cast mining sites in floodplains are endangered by enormous erosion and sediment transport within a short period of time (several hours). Understanding such complex erosion and depositional processes in open-cast mining areas could provide a blueprint for geomorphological processes and hazards in these anthropogenically shaped fluvial landscapes. Further, information on historic impact in the area is crucial to estimate potential risks.

Coastal Storm-Induced Sinkholes: Insights from Unmanned Aerial Vehicle Monitoring

In recent decades, the scientific community has increasingly focused on extreme events linked to climate change, which are leading to more intense and frequent natural disasters. The Mediterranean can be considered a hotspot where the effects of these changes are expected to be more intense compared to other regions of the planet. Italy is not exempt; in fact, with its extensive shoreline, it is particularly vulnerable, especially to high sea levels and coastal erosions. In this framework, from late October to early November 2023, six storm surges occurred in the Gulf of Trieste (NE Italy). These events, characterized by winds from 190°N to 220°N and the significant wave height, which reached up to 1.81 m nearshore—an uncommon meteorological condition in the northern Adriatic Sea—caused the occurrence of eight coastal sinkholes and substantial damages to man-made structures. Thanks to Unmanned Aerial Vehicles (UAVs) and their derived products (high-resolution orthomosaics, Digital Elevation Models—DEMs, and point clouds), it was possible to study these features over time, enabling long-term coastal dynamics monitoring, which can be crucial for timely and effective response and restoration efforts.

The Extent of Agricultural Land Cover Change: The Case of Bautista, Pangasinan

Urban Expansion in Bautista periodically alters its land cover, significantly diminishing agricultural land in favor of built-up areas. Therefore, a comprehensive investigation of past and future land cover changes is essential for sustainable development. The main objective of this research is to determine the extent of agricultural land cover change and its spatial pattern from 2018 to 2022 and in the year 2027 in Bautista, Pangasinan. This study employed a descriptive research approach integrating time series data, spatial analysis, and simulation tools to evaluate the dynamic changes in agricultural land cover. The extent of agricultural land cover change decreased from 3,480.95 hectares in 2018 to 3,417.04 hectares in 2022, primarily near road networks and within the identified urban barangays of the municipality. The change exhibited a clustered distribution, as per the summary report from the Average Nearest Neighbor using the Geographic Information System. In contrast, built-up land cover change expanded by 60.68 hectares from 2018 to 2022, following an increasing trend. Furthermore, the projected agricultural land cover change is expected to decrease continuously from 3,417.039 hectares in 2022 to 3,406.875 hectares in 2027. The results indicate a conversion of agricultural land to built-up areas between 2018 and 2022 and a further decrease in 2027, reflecting a shift from agriculture to man-made structures. This research underscores the importance of monitoring land conversions and provides a basis for sustainable solutions to address the growing demand for urbanization without compromising the future extent of agricultural land cover in Bautista, Pangasinan.

Delineating the climate change impacts on urban environment along with heat stress in the Indian tropical city

India experiences significant levels of temperature variance as a result of urbanization, deforestation, and industrial growth, all of which contribute to a progressive increase in heat island effects. Significant landform change has occurred in Bhubaneswar City, Odisha, in recent decades as a result of major plant loss and temperature unpredictability. Thus, during the summer and winter months, an examination of the long-term heat island impacts is essential for Bhubaneswar. The evolution of landforms and heat island impacts in Bhubaneswar are evaluated using Landsat images from 1991 to 2021 datasets and correlation analysis of heat islands and geospatial variables. Between 1991 and 2021 with a 10-year gap, the landforms studied showed an increase in built-up land (38.009 km2), a decrease in vegetation (13.875 km2), bare ground (16.306 km2), and water bodies (7.828 km2). The annual temperature variance in Bhubaneswar was 0.124 °C (summer), and 0.293 °C (winter). Surface temperatures varied by about 3.71 °C (summer) and 8.80 °C (winter). During the study years, heat islands increased from 2.89 to 4.27 (summer) and 2.30 to 3.87 (winter). In Bhubaneswar, there was an increase in ecological variation of 0.092 (summer), and 0.071 (winter). There is a statistically significant negative correlation between the R2 values and the temperature and the built-up indices. Using this dataset, administrative and development authorities can choose which measures to take to counteract the effects of variations in thermal variation. Finding out how man-made land use structures, industrial zones, and other areas contribute to the built-up area a direct consequence of heat islands was the aim of this study.

Vymezení umělých ostrovů v mezinárodním mořském právu a jeho význam pro spory v Jihočínském moři

This paper explores the concept of islands in international law and its implications for the South China Sea dispute. Islands are important for various reasons, such as territorial sovereignty, maritime rights, and natural resources. However, the legal binding definition of artificial islands has not been enacted by any international document until now. This paper traces the historical development of the concept of islands, from the Hague Conference in 1930 to the United Nations Convention of the Law of the Sea (UNCLOS) in 1982. It also analyses the challenges and opportunities of artificial islands, which are man-made structures that can serve different purposes but can also create various legal and environmental problems. Artificial islands are especially relevant for the South China sea dispute, which involves multiple costal states, while China has significant geopolitical and economic implications. This paper argues that the South China Sea dispute can be resolved through cooperation and dialogue, based on international law framework. Taking into account the provisions of UNCLOS, South China Sea dispute, state practise, and legal scholarship, this article aims to unpack the complexities surrounding artificial island and implications of artificial islands on the international relations.

Application of PS-InSAR and Diagnostic Train Measurement Techniques for Monitoring Subsidence in High-Speed Railway in Konya, Türkiye

Large-scale man-made linear structures like high-speed railway lines have become increasingly important in modern life as a faster and more comfortable transportation option. Subsidence or longitudinal levelling deformation problems along these railway lines can prevent the line from operating effectively and, in some cases, require speed reduction, continuous maintenance or repairs. In this study, the longitudinal levelling deformation of the high-speed railway line passing through Konya province (Central Turkey) was analyzed for the first time using the Persistent Scatter Synthetic Aperture Radar Interferometry (PS-InSAR) technique in conjunction with diagnostic train measurements, and the correlation values between them were found. In order to monitor potential levelling deformation along the railway line, medium-resolution, free-of-charge C-band Sentinel-1 (S-1) data and high-resolution, but paid, X-band Cosmo-SkyMed (CSK) Synthetic Aperture Radar (SAR) data were analyzed from the diagnostic train and reports received from the relevant maintenance department. Comparison analyses of the results obtained from the diagnostic train and radar measurements were carried out for three regions with different deformation scenarios, selected from a 30 km railway line within the whole analysis area. PS-InSAR measurements indicated subsidence events of up to 40 mm/year along the railway through the alluvial sediments of the Konya basin, which showed good agreement with the diagnostic train. This indicates that the levelling deformation of the railway and its surroundings can be monitored efficiently, rapidly and cost-effectively using the InSAR technique.

Investigating topological valley disclinations using multiple scattering and null-field theories

Surprisingly, topological metamaterials became a frontier topic in wave physics. What began as a curiosity driven undertaking in condensed matter physics, evolved in serious possibilities to provide topologically resilient guiding of light, sound and vibrations. Topological defects, in the form of disclinations, dislocations, vortices, etc., have capitalized on man-made structures to demonstrate their wave-confining capabilities. In this report, we discuss topological edge and disclination states in valley Hall sonic lattices. A prime meta-constituent is the three-legged rod or tripod as its mere rotation enables spatial symmetry breaking. For the most part, this complicated unit is numerically treated with commercially available finite element solvers. Here, we derive the structure factor for plane wave expansions and a null-field method in combination with a multiple scattering theory to study both valley edge and disclination states. We showcase how this method enables rapid evaluation of both spatial and spectral properties related to valley topological sound wave physics.

Ground subsidence in major Philippine metropolitan cities from 2014 to 2020

Land subsidence is recognized as one of the hazards that threaten Metro Manila, Philippines, and other major urban areas worldwide. It has become a significant global issue caused by excessive groundwater extraction, rapid urbanization, and natural sediment compaction, exacerbated by climate change through rising sea levels. This paper presents vertical ground motion rates in Philippine metropolitan cities using Sentinel-1 InSAR time series analysis from 2014 to 2020 through UK COMET’s LiCSAR products and the LiCSBAS package of Morishita et al. (2020). The results revealed a maximum subsidence rate of 109 mm/yr in Bulacan Province in Greater Manila. For the first time, this paper also presents ground motion estimates and the following maximum subsidence rates for other Philippine metropolitan cities: 11 mm/yr in Metro Cebu, 38 mm/yr in Metro Davao, 9 mm/yr in Metro Iloilo, and 29 mm/yr in Legazpi City. Areas with remarkably high subsidence rates are observed as circular to elliptical deformation features in vertical motion maps. Sinking areas mostly coincide with industrial and commercial complexes evident as a contiguous distribution of large and expansive man-made structures with distinct radar reflections. Monitoring this hazard is crucial as it increases the risk of floods, building and infrastructure damage, and economic loss, and exposes residents along the coast to worsening tidal incursions and storm surges due to climate change. InSAR is proposed here as a targeted, long-term deformation monitoring tool, especially related to groundwater usage.

Thermo-catalytic reforming pyrolysis of ensiled Saccharina latissima dominated macroalgal pellets for bioenergy production

Marine macroalgae is a biomass resource for the manufacture of fuels and chemicals, which can be sustainably harvested from seaweed farms or from man-made structures where it accumulates as a biofouling organism. However, in temperate regions farmed macroalgae can only be harvested between late Spring and early Summer, limiting year-round availability. Here we show that a conventional grass ensilage procedure preserves Saccharina latissima dominated biomass on the tonne scale for 30 months, enabling year-round use of this biomass. Following processing, the resulting dried and pelletised ensiled macroalgae material was subject to Thermo-Catalytic Reforming™, comprising sequential pyrolysis (450 °C) and either dry or steam catalytic reforming (700 °C) processes. Both processing methods produced a mixture of bio-oil (1.6–1.9 wt%) and hydrogen-rich permanent gases (30.9–31.1 wt%) with higher heating values of 34.8–35.4 MJ/kg and 18.0–24.2 MJ/m3, respectively, together with char (45.5–48.5 % wt). The permanent gases can be used directly for heat generation, while hydro-treatment of the bio-oil would afford a material that can be blended with traditional transport fuels. This work demonstrates that if operated at scale, the combined harvesting, ensilaging and Thermo-Catalytic Reforming™ of preserved macroalgal biomass offers a year-round decentralised energy resource.

Box Type Minor Bridge on Small Rivers in Alluvial Region

Since time immemorial, humankind has been using various techniques to cross the rivers, streams or any depression without closing or obstructing the original flow through a structure called bridge. With the span of time and advancements in civil engineering, several types of bridges have come into existence like wooden, steel, masonry arches, RCC and pre stressed concrete bridges. Indian Roads Congress categorizes three types of the bridges on the basis of length i.e. culverts up to 6.0 m, minor bridges above 6.0 m to maximum 60.0 m length and major bridges above 60.0 m. In present scenario, minor bridges over small rivers has become necessary for development and prosperity of nation as most of the roads have to cross small rivers at several places to connect remotest corner of the country. Bridges, though a manmade structure, over a period become an important part of environment because in most of the cases water flowing below is used for drinking, irrigation and underground recharging. The alluvial region of India spread from Punjab to West Bengal has a peculiar nature because soil is almost soft in nature consisting of mainly sand, clay and silt which is fertile for vegetation. Water retention and its movement condition are high throughout the year. Several type of water bodies which exists in this type of region are pond, small drain, small and medium rivers which drains into the big rivers like Ganga, Yamuna, Ghaghara, Gomati and Sai etc. Since long time, road system on the earthen track and pucca has been introduced for traffic like chart, chariot and motorized vehicle. There were little number of bridges over major rivers i.e. bridge alone to cross over the river Ganga except in few places like Allahabad, Kanpur and Varanasi and over the Ghaghra Algine bridge, Maghighat, Bhatni. Some bridges were constructed over small and medium rivers in medevial period by local rulers and businesspersons, which have now become obsolete. It is found that most of the bridges are of masonry arches wooden and trusses having insufficient water and carriageway. After independence, the road network system has been improved to meet out socio economic needs of people. The new bridges have been constructed with standard road width and sufficient waterway. Study has been conducted for existing new constructed bridge system over small river and alluvial region of Uttar Pradesh to set guidance for future course of action in replacing and providing new bridges to optimize the needs of the people. Bridge system being provided over small & minor rivers for the road network for new and replacement of older bridge at different site is varying from place to place. For this purpose, study has been conducted for sustainable option of minor bridges over small rivers discharge up to 300 m3 /s. It is found that the box type minor bridges are best option on small & minor rivers.

Synergies and Trade-offs Between Cultural and Natural Values of Sacred Sites – a Case Study of Ancient Burial Mounds in Central Europe

In the Eurasian steppes, ancient burial mounds called ‘kurgans’ are among the most widespread manmade structures. These sacred sites hold cultural values and often provide safe havens for grassland-related plant species. We established links between kurgans' cultural and natural values through a comprehensive multi-layered evaluation of human and landscape history, cultural attributes, and botanical composition on selected mounds in Hungary, Romania, and Serbia. We evaluated factors that can support or endanger the grasslands on kurgans and assessed whether there are synergies or trade-offs between the presence of cultural and natural values. We found that kurgans act as cultural hotspots in transformed landscapes, and we found the following evidence for the synergies between cultural and natural values: i) Extensive land use and management connected to the cultural functions could considerably contribute to the preservation of grassland specialist plants on the mounds. ii) Over the past three centuries, most grasslands we studied were converted to cropland, but the cultural importance of the kurgans could hinder their destruction through ploughing or construction works. However, we also found that built cultural objects decreased the grassland cover area and supported the establishment and spread of several weedy and invasive species. Consequently, to preserve the valuable biocultural systems, it is essential to focus efforts on the maintenance of the already existing traditional cultural functions and not the establishment of new objects.

Life on every stone: Characterizing benthic communities from scour protection layers of offshore wind farms in the southern North Sea

The scour protection layer (SPL) is a layer of large stones placed around man-made structures in the marine environment, preventing sediment scouring while also providing new hard substrate and potentially increasing the structural complexity of the original environment. This fosters development of diverse benthic communities, supporting high abundance of organisms. Future SPLs are therefore a potential tool for the ecological enhancement of degrading marine habitats following the principles of nature-inclusive design. Yet, factors that shape the benthic communities on SPLs are poorly understood. Here, we analysed existing data from SPLs from offshore wind farms and a gas platform in the southern North Sea to determine how SPL characteristics affect the biofouling community structure. We combined this analysis with an in-situ experiment testing for the effects of habitat complexity on SPL communities. Our results demonstrate that abundant and diverse communities are present on all SPLs. On a regional scale, communities are mainly affected by depth and location. Increasing habitat complexity has significant and positive effects on species richness yet was non-significant for biomass and abundance of the biofouling community. If applied thoughtfully, nature-inclusive design of the SPL habitat, including manipulation of the physical complexity of the structure, can effectively promote biodiversity.

Investigating worldwide strong motion databases to derive a collection of free-field records to select design-compatible waveforms for Switzerland

The process of choosing ground motions typically relies on assembling a collection of ground motions that match a desired spectrum. This selection process is guided by specific seismological criteria, including factors like earthquake magnitude, distance from the epicenter, site soil type, and the range of spectral periods that need to fit with the target spectrum. The selection algorithm and the available dataset of waveforms obviously play significant roles in this process. In many engineering and site response applications, it is essential that the input ground motion is representative for the shaking at the free surface of the Earth, and at times also a specific soil type may be required. However, real waveform databases often lack sufficient and/or consistent metadata related to the installation type and soil characterization of recording stations, as well as to the earthquake seismological parameters. This deficiency can lead to the selection of inappropriate waveforms, such as those recorded by stations situated within manmade structures (buildings, bridges, dams) or on a soil type different than the intended one. To address this issue, our approach for creating an appropriate waveform database applicable to Switzerland starts with the computation of seismic hazard disaggregation for return periods of 475 and 975 years. This computation helps identifying the magnitude-distance scenarios most relevant for the five seismic hazard zones defined in the Swiss building code. Once these magnitude-distance ranges are identified, we adhere to established standards regarding the quality control of three-component waveforms and their associated metadata. We assemble a database of waveforms by collating and homogenizing data from available global databases. In the interest of comprehensiveness, we also incorporate data obtained from 3D physics-based numerical simulations of strong-motion near the seismic source. Finally, we employ an algorithm that integrates the Eurocode 8 waveform selection criteria. This algorithm allows us to select and scale waveforms suitable for microzonation and structural analysis studies within each of Switzerland’s five seismic hazard zones. Selecting waveforms compatible with the target design spectra proves to be challenging due to the stringent criteria imposed by Eurocode 8. This challenge arises from the scarcity of recorded waveforms with verified metadata and precise site characterization in the desired magnitude-distance ranges.

Urban Flood Modelling: A Geospatial Evaluation of Drainage Systems for Resilient City Planning in Lusaka

This study presents a flood modelling approach aimed at enhancing planning strategies to mitigate flooding impacts in LusakaCity. By integrating factors such as slope, hydrostatic potential surface, and the built environment, a predictive flood modelwas developed. The methodology involved using Geographic Information System (GIS) techniques and digital elevationmodels (DEMs) to assess geological features and manmade structures. Precipitation patterns and water demand analysesaided in computing a hydrostatic potential surface through watershed delineation. The generated flood model producedcomprehensive flood maps illustrating water drainage in Lusaka, identifying vulnerable areas using Multi-Criteria DecisionAnalysis (MCDA) techniques. Results highlight the complex interaction between geographical features and humaninfrastructure in flood dynamics. This study contributes to informing zoning policies and disaster response planning, aimingto reduce the impact of future flooding events.

Discovery of novel Nodosilinea species (Cyanobacteria, Nodosilineales) isolated from terrestrial habitat in Ryukyus campus, Okinawa, Japan

Terrestrial cyanobacteria are extremely diverse. In urban areas, they can be found as black stains on the surface of building walls, stone monuments, or man-made structures. Many of the terrestrial cyanobacteria are still understudied. To expand knowledge of terrestrial cyanobacterial diversity, a polyphasic characterization was performed to identify 12 strains isolated from campus of University of the Ryukyus, Okinawa, Japan. Multigene phylogenetic analyses based on 16S rRNA gene and 16S-23S rRNA internal transcribed spacer (ITS) region showed that the isolated strains formed two independent subclades within Nodosilinea, and were distantly related to all described Nodosilinea species. The 16S-23S rRNA ITS secondary structures showed variations for D1-D1′ and Box B domain, while V3 domain was almost identical among entire species of Nodosilinea, including the studied strains. In addition, a unique morphological character, i.e. forming nodule or spiral shape, was also observed in certain studied strains. According to polyphasic characterization, Nodosilinea coculeatus sp. nov. and Nodosilinea terrestrialis sp. nov., were proposed as two new species of terrestrial cyanobacteria from Okinawa.