Search Results (9)

The ornamentation of historical buildings in Iran often features geometric patterns, which hold cultural and architectural significance. These patterns, rooted in Islamic tradition, are widely used in contemporary Middle Eastern architecture. By employing regular polygons, intricate designs emerge, forming interconnected tessellations and repeating modules. This paper focuses on uncovering hidden tessellations and geometric patterns within the southern Iwan of the Grand Mosque of Varamin. Through photography and field measurements, 8².4 and 3⁶ tessellations were identified. Using the Revit 2024 program, a novel method was introduced to model these patterns. By manipulating repeating units, designers can create diverse geometric latticework, preserving Islamic architectural heritage. Furthermore, these patterns offer practical applications beyond ornamentation. They can serve as architectural elements in urban environments, such as fences or enclosures, enhancing privacy in residential spaces and contributing to urban aesthetics. This approach facilitates the integration of historical patterns into contemporary architectural designs, enriching both cultural identity and urban landscapes and is a step toward smart cities. Full article

Remote sensing was used to map the invasion of yellow-flowered legumes on the Central Plateau of New Zealand to inform weed management strategy. The distributions of Cytisus scoparius (broom), Ulex europaeus (gorse) and Lupinus arboreus (tree lupin) were captured with high-resolution RGB photographs of the plants while flowering. The outcomes of herbicide operations to control C. scoparius and U. europaeus over time were also assessed through repeat photography and change mapping. A grid-square sampling tool previously developed by Manaaki Whenua—Landcare Research was used to help transfer data rapidly from photography to maps using manual classification. Artificial intelligence was trialled and ruled out because the number of false positives could not be tolerated. Future actions to protect the natural values and vistas of the Central Plateau from legume invasion were identified. While previous control operations have mostly targeted large, highly visible legume patches, the importance of removing outlying plants to prevent the establishment of new seed banks and slow spread has been underestimated. Outliers not only establish new, large, long-lived seed banks in previously seed-free areas, but they also contribute more to range expansion than larger patches. Our C. scoparius and U. europaeus change mapping confirms and helps to visualise the establishment and expansion of uncontrolled outliers. The power of visualizing weed control strategies through remote sensing has supported recommendations to improve outlier control to achieve long-term, sustainable landscape-scale suppression of invasive legumes. Full article

Repeat photography, the process of locating the camera position of an old photo and taking a new photo from this position, is utilized to protect our natural heritage, by measuring landscape changes between old and new image, and to conserve and recover our architectural and archaeological heritage, by observing changes between images taken before, during, and after conservation efforts or destructive events. Most importantly, repeat photography—in short, rephotography—is connecting us to our heritage on all levels from personal to global: while rephotographing, we connect with the old image and its creator and—when viewing and comparing the old image and the rephotograph—we connect with the tangible, intangible, and natural heritage shown in the images by observing changes and continuities. In this paper, we review publications and applications employing rephotography. We discuss the organization, retrieval, and presentation of rephotographic compilations, their generation by different image registration techniques, and their conservation as rephotographic heritage. Further, we describe challenges in rephotography, discuss how they differ from standard challenges in photography, computer vision, and image registration and present both analog and digital solutions and tools used in practice by rephotographers to address said challenges. Full article

The interaction between humans and nature dramatically reveals the role of sudden and destructive events in the progressive and never-ending trend of depletion of the territorial dimension of the Belìce Valley (Valle del Belìce, Sicily, Italy). If on the one hand a tragic event, such as the earthquake of 1968, that destroyed towns and villages in the Belìce Valley, represented a moment of pain and suffering for local communities and their territories, on the other, more than 50 years after the event, we are able to shed light on the reaction to the earthquake effects through an in-depth analysis of the heritage of the physical and immaterial rubble. Our research is aimed at framing, through special geovisual tools, the paths of this rebuilding process and to verify whether the “new” interaction of humans and nature has reached an acceptable balance. After introducing the concept of landscape and investigating some local manifestations within the Belìce Valley, we tackle the technical question of re-photography as a powerful and quick method for observing the territorial changes that occurred after the earthquake. This approach is based on the collection of historical photographs and, subsequently, onsite activities for the creation of a contemporary archive of images. The method used for comparing the images was that of re-photographic overlapping, a useful technique to compare different moments of the history of a landscape and to analyze the effectiveness of the process of rebuilding. Finally, this analysis introduces us to a new perspective where in our opinion, it is possible to frame some features of the Belìce Valley and some more general aspects that are useful for other territories hit by destructive events and having to face choices related to the future of their communities. Full article

Alpine Treeline Ecotone (ATE), the typically gradual transition zone between closed canopy forest and alpine tundra vegetation in mountain regions, displays an elevational range that is generally constrained by thermal deficits. At landscape scales, precipitation and moisture regimes can suppress ATE elevation below thermal limits, causing variability in ATE position. Recent studies have investigated the relative effects of hydroclimatic variables on ATE position at multiple scales, but less attention has been given to interactions between hydroclimatic variables and disturbance agents, such as fire. Advances in monoplotting have enabled the extraction of canopy cover information from oblique photography. Using airborne lidar, and repeat photography from the Mountain Legacy Project, we observed canopy cover change in West Castle Watershed (Alberta, Canada; ~103 km²; 49.3° N, 114.4° W) over a 92-year period (1914–2006). Two wildfires, occurring 1934 and 1936, provided an opportunity to compare topographic patterns of mortality and succession in the ATE, while factoring by exposure to fire. Aspect was a strong predictor of mortality and succession. Fire-exposed areas accounted for 83.6% of all mortality, with 72.1% of mortality occurring on south- and east-facing slope aspects. Succession was balanced between fire-exposed and unburned areas, with 62.0% of all succession occurring on north- and east-facing slope aspects. The mean elevation increase in closed canopy forest (i.e., the lower boundary of ATE) on north- and east-facing undisturbed slopes was estimated to be 0.44 m per year, or ~44 m per century. The observed retardation of treeline advance on south-facing slopes is likely due to moisture limitation. Full article

Norway has a political goal to minimize the loss of cultural heritage due to removal, destruction or decay. On behalf of the national Directorate for Cultural Heritage, we have developed methods to monitor Cultural Heritage Environments. The complementary set of methods includes (1) landscape mapping through interpretation of aerial photographs, including field control of the map data, (2) qualitative and quantitative initial and repeat landscape photography, (3) field recording of cultural heritage objects including preparatory analysis of public statistical data, and (4) recording of stakeholder attitudes, perceptions and opinions. We applied these methods for the first time to the historical clustered farm settlement of Havrå in Hordaland County, West Norway. The methods are documented in a handbook and can be applied as a toolbox, where different monitoring methods or frequency of repeat recording may be selected, dependent on local situations, e.g., on the landscape character of the area in focus. Full article

Time series of repeat aerial photographs currently span decades in many regions. However, the lack of calibration data limits their use in forest change analysis. We propose an approach where we combine repeat aerial photography, tree-ring reconstructions, and Bayesian inference to study changes in forests. Using stereopairs of aerial photographs from five boreal forest landscapes, we visually interpreted canopy cover in contiguous 0.1-ha cells at three time points during 1959–2011. We used tree-ring measurements to produce calibration data for the interpretation, and to quantify the bias and error associated with the interpretation. Then, we discerned credible canopy cover changes from the interpretation error noise using Bayesian inference. We underestimated canopy cover using the historical low-quality photographs, and overestimated it using the recent high-quality photographs. Further, due to differences in tree species composition and canopy cover in the cells, the interpretation bias varied between the landscapes. In addition, the random interpretation error varied between and within the landscapes. Due to the varying bias and error, the magnitude of credibly detectable canopy cover change in the 0.1-ha cells depended on the studied time interval and landscape, ranging from −10 to −18 percentage points (decrease), and from +10 to +19 percentage points (increase). Hence, changes occurring at stand scales were detectable, but smaller scale changes could not be separated from the error noise. Besides the abrupt changes, also slow continuous canopy cover changes could be detected with the proposed approach. Given the wide availability of historical aerial photographs, the proposed approach can be applied for forest change analysis in biomes where tree-rings form, while accounting for the bias and error in aerial photo interpretation. Full article

Vegetation and land-cover changes are not always directional but follow complex trajectories over space and time, driven by changing anthropogenic and abiotic conditions. We present a multi-observational approach to land-change analysis that addresses the complex geographic and temporal variability of vegetation changes related to climate and land use. Using land-ownership data as a proxy for land-use practices, multitemporal land-cover maps, and repeat photography dating to the late 19th century, we examine changing spatial and temporal distributions of two vegetation types with high conservation value in the southwestern United States: grasslands and riparian vegetation. In contrast to many reported vegetation changes, notably shrub encroachment in desert grasslands, we found an overall increase in grassland area and decline of xeroriparian and riparian vegetation. These observed change patterns were neither temporally directional nor spatially uniform over the landscape. Historical data suggest that long-term vegetation changes coincide with broad climate fluctuations while fine-scale patterns are determined by land-management practices. In some cases, restoration and active management appear to weaken the effects of climate on vegetation; therefore, if land managers in this region act in accord with on-going directional changes, the current drought and associated ecological reorganization may provide an opportunity to achieve desired restoration endpoints. Full article

Urban forest ecosystems provide a range of social and ecological services, but due to the heterogeneity of these canopies their spatial extent is difficult to quantify and monitor. Traditional per-pixel classification methods have been used to map urban canopies, however, such techniques are not generally appropriate for assessing these highly variable landscapes. Landsat imagery has historically been used for per-pixel driven land use/land cover (LULC) classifications, but the spatial resolution limits our ability to map small urban features. In such cases, hyperspatial resolution imagery such as aerial or satellite imagery with a resolution of 1 meter or below is preferred. Object-based image analysis (OBIA) allows for use of additional variables such as texture, shape, context, and other cognitive information provided by the image analyst to segment and classify image features, and thus, improve classifications. As part of this research we created LULC classifications for a pilot study area in Seattle, WA, USA, using OBIA techniques and freely available public aerial photography. We analyzed the differences in accuracies which can be achieved with OBIA using multispectral and true-color imagery. We also compared our results to a satellite based OBIA LULC and discussed the implications of per-pixel driven vs. OBIA-driven field sampling campaigns. We demonstrated that the OBIA approach can generate good and repeatable LULC classifications suitable for tree cover assessment in urban areas. Another important finding is that spectral content appeared to be more important than spatial detail of hyperspatial data when it comes to an OBIA-driven LULC. Full article