Search Results (10)

Understanding landscape fragmentation is crucial to explore comprehensive land-use–land-cover (LULC) change within fast-growing urbanisation. While LULC change is a global concern, limited research explores landscape fragmentation along river and road infrastructure in high-density riverine contexts. This study addresses this gap through understanding dynamic landscape fragmentation patterns to track LULC in the Ciliwung River, Indonesia, from 1990 to 2020. The research employed remote sensing, GIS, R programming with Landsat data, Normalised Difference Vegetation Index (NDVI) values, buffering, and landscape metrics. The findings show minimal fragmentation was concentrated downstream near Jakarta, while significant fragmentation, manifesting as green loss, occurred in the midstream. Buffer analysis showed high green loss in the upstream segment both near the river and roads, particularly within a 0–400 m buffer. However, landscape metrics identified changes in the midstream close to the river buffer (0–200 m) indicating that riparian green spaces in this area persist as relatively large but ecologically unconnected “chunks”. The stability of these remaining patches makes them a crucial asset for targeted restoration. These findings contribute to a deeper understanding of how river and road networks influence the change, highlighting the integral role of remote sensing and GIS in monitoring LULC change for natural preservation. Full article

The strength mobilisation framework was adopted for the first time to describe the stress–strain responses for three different types of sands, including a total of 30 published drained triaxial tests—25 for Karlsruhe Fine Sand, 2 for Ottawa sands and 3 for Fontainebleau sand, under confining pressures ranging from 50 to 400 kPa. The peak shear strength ${\tau }_{peak}$ obtained from drained triaxial shearing of these sands was used to normalise shear stress. Shear strains normalised at peak strength ${\gamma }_{peak}$ and at half peak of shear strength ${\gamma }_{M=2}$ were taken as the normalised reference strains, and the results were compared. Power–law functions were then derived when the mobilised strength was between $0.2{\tau }_{peak}$ and $0.8{\tau }_{peak}$. Exponents of the power–law functions of these sands were found to be lower than in the published undrained shearing data of clays. Using ${\gamma }_{M=2}$ as the reference strain shows a slightly better power–law correlation than using ${\gamma }_{peak}$. Linear relationships between the reference strains and variables, such as relative density, relative dilatancy index, and dilatancy, are identified. Full article

Rainwater harvesting (RWH) has emerged as a promising technique to improve water security amid the escalating effects of climate change. However, a comprehensive evaluation of various rainwater harvesting solutions is needed to promote sustainable practices in the building sector. This study aims to evaluate the water saving potential in multi- and single-family social housing buildings in twelve cities in Brazil. Computer simulations were performed for 60 scenarios, comprising five social housing reference models and using rainfall data from twelve representative cities of Brazil’s bioclimatic zones. The results show that single-family houses presented a higher potential for potable water savings (20 to 22%) than multi-family housing models (2 to 3%), mainly due to their higher roof-area-to-resident ratio. Single-family buildings exhibit more significant variability in absolute savings (standard deviation), while multi-family buildings are more sensitive to variability relative to their means (higher CVs). Furthermore, due to uneven rainfall distribution and storage limitations, water savings potential does not correlate linearly with total annual rainfall. Normalised results reveal that buildings with a lower population density achieve higher water savings per area and inhabitant. This study demonstrated that building and climate characteristics influence rainwater harvesting, offering valuable insights for promoting sustainable water management practices in social housing. Full article

Human impact on natural ecosystems is unsustainable and has led to a significant loss of biodiversity, highlighting the importance of protected area networks such as the European Union’s Natura 2000 (N2000). This study assesses the effectiveness of Special Areas of Conservation (SACs) in mainland Spain, using a Normalised Relative Severity Index (SER) computed from land condition states of ecological maturity (2010–2020). A total of 596 SACs were analysed, comparing their SER index with that of unprotected areas. Biophysical characteristics such as elevation, tree cover density, and human impact were used for explanatory purposes. At the national level, SACs exhibit a significantly higher median SER index than unprotected areas, indicating a better overall land condition status within N2000. However, regional variations were observed, with some Autonomous Communities in the Atlantic showing better land conditions outside N2000, which is attributed to vigorous vegetation growth in marginal areas. Differences in the SER index between inside and outside N2000 are proportional to the isolation degree of SACs. The study demonstrates that N2000 positively contributes to land conservation in mainland Spain. Nevertheless, it emphasizes the need to consider regional specificities and manage non-protected areas for more effective long-term conservation, especially in the Mediterranean region. Full article

Skeletal gyroid structures possess promising applications in biomedical implants, owing to their smooth and continuously curved surfaces, open porosity, and customisable mechanical properties. This study simulated the geometric properties of Ti6Al4V skeletal gyroid structures, with relative densities ranging from 1.83% to 98.17%. The deformation behaviour of these structures was investigated through a combination of uniaxial compression tests and simulations, within a relative density range of 13.33% to 50% (simulation) and 15.19% to 41.69% (experimental tests). The results established explicit analytical correlations of pore size and strut diameter with the definition parameters of the structures, enabling precise control of these dimensions. Moreover, normalised Young’s modulus (ranging from 1.05% to 20.77% in simulations and 1.65% to 15.53% in tests) and normalised yield stress (ranging from 1.75% to 17.39% in simulations and 2.09% to 13.95% in tests) were found to be power correlated with relative density. These correlations facilitate the design of gyroid structures with low stiffness to mitigate the stress-shielding effect. The presence of macroscopic 45° fractures in the gyroid structures confirmed that the primary failure mechanism is induced by shear loads. The observed progressive failure and plateau region proved the bending-dominant behaviour and highlighted their excellent deformability. Additionally, the anisotropy of gyroid structures was confirmed through variations in stress and strain concentrations, deformation behaviour, and Young’s modulus under different loading directions. Full article

During an earthquake, excess pore water pressure generation in saturated silty sands causes a reduction in shear strength and even liquefaction of the soil. A comprehensive experimental program consisting of undrained cyclic simple-shear tests was undertaken to explore the key factors affecting the energy-based excess pore water pressure generation models for non-plastic silty sands. The examined influencing factors were non-plastic fines content (less than and greater than the threshold value ≅ 25%), packing density, vertical effective stress, applied cyclic stress ratio, and soil fabric. The relationship between excess pore water pressure ratio and dissipated energy per unit volume was found to be mainly dependent on the relative density and fines content of soil, whereas the cyclic stress ratio, initial vertical effective stress, and soil fabric (i.e. the reconstitution method) appeared to have a minor impact. A revision of the original energy-based model developed for clean sand by Berrill and Davis was proposed to improve prediction accuracy in terms of residual excess pore water pressures versus normalised cumulative dissipated energy. Nonlinear multivariable regression analyses were performed to develop correlations for the calibration parameters of the revised model. Lastly, these correlations were validated through additional cyclic simple-shear tests performed on different silty sands recovered at a site where liquefaction occurred after the 2012 Emilia Romagna (Italy) earthquake. Full article

The geodiversity of loess areas is reflected in the characteristic dataset of loess landforms, with the dominance of several types of valley forms (mainly gullies). The availability of satellite elevation data and high-resolution aerial topography scanning data provides an opportunity for quantitative assessment of geomorphodiversity. This is done through the analysis of topographic texture, delimitation and statistical characterization of the topographic parameters of erosional landforms, such as volume and degree of dissection (density of valleys) or the degree of ‘coverage’ of the area by valley forms. An important factor affecting the accuracy of the estimation is the accuracy of the underlying digital terrain model (DTM). This study compares three digital terrain models, with cell sizes of 30, 10 and 1 m, generated from satellite altimetry data and airborne laser scanning (ALS) data. The subregion of Szczebrzeszyn Roztocze (Western Roztocze Region, SE Poland), i.e., one of the most typical loess relief regions in Poland, was selected as the study area. Selected topographic texture analyses were carried out using the SLRM (Simple Local Relief Model) algorithm. Delimitation of valleys was performed by delineating the extent of slope change in two key steps: (1) detection of areas below the average topographic surface; (2) delimitation using supervised classification of DTMs. The results of the study show that the accuracy of delimitation of valleys increases inversely proportional to the DTMs resolution. Automated topographic texture analysis allows delimitation and extraction, as well as statistical analysis of parameters of valleys. Finally, two indicators have been proposed, Relative Valley Area (RVA) and Area-normalised Valley Cubature (AVC), which can be used in geomorphodiversity studies of a geologically homogeneous area. The dimensionless RVA index can also be expressed as a percentage (%) of the area of valley forms in a basic field of 1 km². Furthermore, the AVC index shows the dynamic character of the main relief features of the analysed area. Full article

In offshore engineering, the sand beneath an embankment may be subjected to traffic loads, resulting in a series of engineering issues. The behaviour of the sand beneath the embankment may change under a long-term traffic load. A series of drained cyclic and post-cyclic monotonic triaxial tests were performed on Fujian sand with different relative densities. The drained strength and stress–dilatancy behaviours were studied. The results indicated that the normalised peak strength ratio after cyclic loading was greater than that without cyclic loading, depending on the cyclic stress amplitude, while the critical state strength seemed to be only slightly affected by the cyclic loading history. The dilative response of sand could also be influenced by cyclic loading-induced fabric. Under constant relative density conditions, the higher the cyclic stress amplitude applied to the sand sample, the larger the volume strain produced in the critical state. Furthermore, cyclic-induced fabric could be destroyed after 6% axial strain. Full article

Soil compaction (SC) is a major threat for agriculture in Europe that affects many ecosystem functions, such as water and air circulation in soils, root growth, and crop production. Our objective was to present the results from five short-term (<5 years) case studies located along the north–south and east–west gradients and conducted within the SoilCare project using soil-improving cropping systems (SICSs) for mitigating topsoil and subsoil SC. Two study sites (SSs) focused on natural subsoil (˃25 cm) compaction using subsoiling tillage treatments to depths of 35 cm (Sweden) and 60 cm (Romania). The other SSs addressed both topsoil and subsoil SC (˃25 cm, Norway and United Kingdom; ˃30 cm, Italy) using deep-rooted bio-drilling crops and different tillage types or a combination of both. Each SS evaluated the effectiveness of the SICSs by measuring the soil physical properties, and we calculated SC indices. The SICSs showed promising results—for example, alfalfa in Norway showed good potential for alleviating SC (the subsoil density decreased from 1.69 to 1.45 g cm⁻¹) and subsoiling at the Swedish SS improved root penetration into the subsoil by about 10 cm—but the effects of SICSs on yields were generally small. These case studies also reflected difficulties in implementing SICSs, some of which are under development, and we discuss methodological issues for measuring their effectiveness. There is a need for refining these SICSs and for evaluating their longer-term effect under a wider range of pedoclimatic conditions. Full article

Inverse Tone Mapping (ITM) methods attempt to reconstruct High Dynamic Range (HDR) information from Low Dynamic Range (LDR) image content. The dynamic range of well-exposed areas must be expanded and any missing information due to over/under-exposure must be recovered (hallucinated). The majority of methods focus on the former and are relatively successful, while most attempts on the latter are not of sufficient quality, even ones based on Convolutional Neural Networks (CNNs). A major factor for the reduced inpainting quality in some works is the choice of loss function. Work based on Generative Adversarial Networks (GANs) shows promising results for image synthesis and LDR inpainting, suggesting that GAN losses can improve inverse tone mapping results. This work presents a GAN-based method that hallucinates missing information from badly exposed areas in LDR images and compares its efficacy with alternative variations. The proposed method is quantitatively competitive with state-of-the-art inverse tone mapping methods, providing good dynamic range expansion for well-exposed areas and plausible hallucinations for saturated and under-exposed areas. A density-based normalisation method, targeted for HDR content, is also proposed, as well as an HDR data augmentation method targeted for HDR hallucination. Full article