Search Results (13)

With industrial transformation and the rise in the 15 min community life circle, optimizing walkability and preserving industrial heritage are key to revitalizing former industrial areas. This study, focusing on Shijingshan District in Beijing, proposes a walkability evaluation framework integrating multi-source big data and street-level perception. Using Points of Interest (POI) classification, which refers to the categorization of key urban amenities, pedestrian network modeling, and street view image data, a Walkability Friendliness Index is developed across four dimensions: accessibility, convenience, diversity, and safety. POI data provide insights into the spatial distribution of essential services, while pedestrian network data, derived from OpenStreetMap, model the walkable road network. Street view image data, processed through semantic segmentation, are used to assess the quality and safety of pedestrian pathways. Results indicate that core communities exhibit higher Walkability Friendliness Index scores due to better connectivity and land use diversity, while older and newly developed areas face challenges such as street discontinuity and service gaps. Accordingly, targeted optimization strategies are proposed: enhancing accessibility by repairing fragmented alleys and improving network connectivity; promoting functional diversity through infill commercial and service facilities; upgrading lighting, greenery, and barrier-free infrastructure to ensure safety; and delineating priority zones and balanced enhancement zones for differentiated improvement. This study presents a replicable technical framework encompassing data acquisition, model evaluation, and strategy development for enhancing walkability, providing valuable insights for the revitalization of industrial districts worldwide. Future research will incorporate virtual reality and subjective user feedback to further enhance the adaptability of the model to dynamic spatiotemporal changes. Full article

Permanent Scatterer Interferometric Synthetic Aperture Radar (PSInSAR), with millimeter-level accuracy and full-resolution capabilities, is essential for monitoring urban deformation. With the advancement of SAR sensors in spatial and temporal resolution and the expansion of wide-swath observation capabilities, the number of permanent scatterers (PSs) in high-density urban areas has surged exponentially. To address these computational and memory challenges in high-density urban PSInSAR processing, this paper proposes an efficient method for integrating regular grid partitioning and connected component constraints. First, adaptive dynamic regular grid partitioning was employed to divide monitoring areas into sub-blocks, balancing memory usage and computational efficiency. Second, a weighted least squares adjustment model using common PS points in overlapping regions eliminated systematic inter-sub-block biases, ensuring global consistency. A graph-based connected component constraint mechanism was introduced to resolve multi-component segmentation issues within sub-blocks to preserve discontinuous PS information. Experiments on TerraSAR-X data covering Fuzhou, China (590 km²), demonstrated that the method processed 1.4 × 10⁷ PS points under 32 GB memory constraints, where it achieved a 25-fold efficiency improvement over traditional global PSInSAR. The deformation rates and elevation residuals exhibited high consistency with conventional methods (correlation coefficient ≥ 0.98). This method effectively addresses the issues of memory overflow, connectivity loss between sub-blocks, and cumulative merging errors in large-scale PS networks. It provides an efficient solution for wide-area millimeter-scale deformation monitoring in high-density urban areas, supporting applications such as geohazard early warning and urban infrastructure safety assessment. Full article

The trend of gated communities is becoming the new alternative housing for the high-end residents of Jordan, reflecting global patterns of urbanisation. However, their emergence on the outskirts of Amman on vacant lands requires an early proactive planning approach to ensure their development in response to the growth of the surrounding areas, fostering an integrated urban fabric. This article examines whether gated communities contribute to urban discontinuity and lead to social segregation. The study employs a space syntax analysis on two cases in Amman to assess their integration, accessibility, and navigability to address the study’s key questions related to its integration, design implications, and spatial layout. Findings reveal significant spatial segregation, with low levels of integration and high step depth values, indicating potential challenges in navigation, connectivity, residents’ mobility, accessibility, and safety. The article suggests the importance of re-evaluating the design and planning approaches for these developments to promote organic townscape growth to ensure smooth integration with the surroundings. Full article

The city, like a piece of architecture, is a structure in space, but one of gigantic scale, something perceived only over a long period. A space is termed a place when it acquires an identity. The entirety of urban personality, urban communication, urban conduct, and urban design constitute the urban identity. This research delves into divided urban identities and examines how urban and architectural design influence the fragmentation of the cityscape. It explores the connection between urban environments’ physical attributes and the divide of social, cultural, and political identities within cities. This study uses a multidisciplinary method to acquire thorough knowledge by combining architectural studies, urban planning theories, and social-cultural perspectives. The case study of reference is the city of Matera, in southern Italy, which has a unique history of a slow shaping of its urban and productive landscape throughout centuries due to heavy environmental constraints and resource availability and which has suffered forced evacuation and major discontinuities in the past century. Here, the opposing traits of the historical Sassi district and the new town are examined, focusing on their resulting separated urban identities. The study also looks at how divided cities may be reconciled and integrated, emphasizing the relevance of a holistic urban approach for the framing of complex issues. The research proposes methods and best practices for developing inclusive urban settings that promote cohesion and shared identities through the analysis of successful cases of urban regeneration, adaptive reuse of spaces, and participatory design processes. The findings of this research contribute to both academic and practical knowledge by deepening the understanding of the relationship between urban design, architecture, and divided urban identities. It emphasizes the value of comprehensive approaches to urban planning that take into account the social, cultural, and historical settings of cities to foster inclusivity, rapprochement, and the development of common urban identities. Full article

The reintroduction of natural components into the urban environment has several benefits for the adaptation of urban environments. The urban green infrastructure (UGI) approach makes it possible to develop greening programs on a sound scientific basis and in connection with the ability to provide ecosystem services. However, in practice, UGI programs are almost exclusively based on the concept of a continuous green network, which requires large-scale interventions such as green corridors and parks. This severely limits the extension of UGI in dense urban areas such as historic centers. This article introduces the concept of green fragments and proposes an integrative approach to support greater spatial flexibility of the UGI. By setting appropriate limits on the number and proximity of green fragments, the resulting green system keeps functional connectivity despite being physically discontinuous. The proposed approach was tested in the case study of the historical center of Milan, leading to the proposal of integrations regarding the identification and mapping of the existing UGI and the planning of its future extension. Full article

Unmanned Aerial Vehicles (UAVs) have emerged as a compelling alternative to manned operations, offering the capability to navigate hazardous environments without risks for human operators. Despite their potential, optimizing UAV missions in complex and unstructured environments remains a pivotal challenge. Path planning becomes a crucial aspect to increase mission efficiency, although it is inherently complex due to various factors such as obstacles, no-fly zones, non-cooperative aircraft, and flight mechanics limitations. This paper presents a path-planning technique for fixed-wing unmanned aerial vehicles (UAVs) based on the Theta* algorithm. The approach introduces innovative features, such as the use of Euler spiral, or clothoids, to serve as connection arcs between nodes, mitigating trajectory discontinuities. The design of clothoids can be linked to the aircraft performance model, establishing a connection between curvature constraints and the specific characteristics of the vehicle. Furthermore, to lower the computational burden, the implementation of an adaptive exploration distance and a vision cone was considered, reducing the number of explored solutions. This methodology ensures a seamless and optimized flight path for fixed-wing UAVs operating in static environments, showcasing a noteworthy improvement in trajectory smoothness. The proposed methodology has been numerically evaluated in several complex test cases as well as in a real urban scenario to prove its effectiveness. Full article

Our paper aims to analyze the tendencies of population dynamics in the area of the Romanian Carpathians, as well as the factors and spatial processes that can explain the disparities, discontinuities and tensions of demographic evolution. Starting from the hypothesis of an existing set of well-known particularities of the three areas of the Romanian Carpathians (Eastern, Southern and Western), in close connection with the specific manner of using natural and human resources of each area, the main objective of our study is to pinpoint the significant aspects of depopulation and population redistribution. The database was established resorting to censuses from 1912 to the present time. Coupled with a typology of population evolution, a regression analysis was used to assess the relationship between population size changes through time and other variables. The results highlight the contrast between the sustained dynamic in the first part of our study period and the subsequent decline, particularly in the case of establishments specialized in industrial extraction activities. Despite all this, clear signs and tendencies of revitalization and dynamism can be observed, especially where urban and rural settlements are well adapted to the natural environment and can benefit from a significant tourism potential. Full article

Compared to traditional onsite steel construction, prefabricated industrial steel construction (PFISC) saves time, money, and resources. It results in sustainable steel structures that use fewer resources and are better for the environment. Despite their advantages, the private sector favors creating high-rise buildings in an old-fashioned way. In order to encourage the adaptability of prefabricated industrial steel buildings (PFISBs) in high-rise structures, this study critically evaluates the adaptable solutions offered in the literature on the recent developments, structural performances, present difficulties, and future potential. In mid-rise and low-rise structures, PFISC is frequently used. In research and case studies, PFISBs have proven to perform admirably under various adverse conditions, including in the event of an earthquake, wind, blast, impact, fire, collapse, and long-term sustained loads. The use of potential research solutions, the “Top-down” strategy, and the resolving of problems such as the structural-based design guidelines, column stability, discontinuous vertical and horizontal diaphragms, cluster columns and beams effect, damage-free and innovative inter- and intra-modular connections, high strength-to-weight modules, numerical simulation, and transportation will help PFISBs to become more widely accepted in high-rise structures. Compared to other materials, steel has recently demonstrated great promise for the construction of PFISBs. Additionally, China plans to increase their PFISC to 30% by 2026, Australia to 15% by 2025, and North America to over 5% by 2023, proving that it is a reasonable response to future urbanization concerns. Full article

High-resolution traffic data, comprising trajectories of individual road users, are of great importance to the development of Intelligent Transportation Systems (ITS), in which they can be used for traffic microsimulations and applications such as connected vehicles. Roadside laser scanning systems are increasingly being used for tracking on-road objects, for which tracking-by-detection is the widely acknowledged method; however, this method is sensitive to misdetections, resulting in shortened and discontinuous object trajectories. To address this, a Joint Detection And Tracking (JDAT) scheme, which runs detection and tracking in parallel, is proposed to mitigate miss-detections at the vehicle detection stage. Road users are first separated by moving point semantic segmentation and then instance clustering. Afterwards, two procedures, object detection and object tracking, are conducted in parallel. In object detection, PointVoxel-RCNN (PV-RCNN) is employed to detect vehicles and pedestrians from the extracted moving points. In object tracking, a tracker utilizing the Unscented Kalman Filter (UKF) and Joint Probabilistic Data Association Filter (JPDAF) is used to obtain the trajectories of all moving objects. The identities of the trajectories are determined from the results of object detection by using only a certain number of representatives for each trajectory. The developed scheme has been validated at three urban study sites using two different lidar sensors. Compared with a tracking-by-detection method, the average range of object trajectories has been increased by >20%. The approach can also successfully maintain continuity of the trajectories by bridging gaps caused by miss-detections. Full article

Maresme is a littoral region of Barcelona (Spain) in which the railway and an important road run along the coastline with a high landscape impact. Over time, several facilities connected to these transport infrastructures have appeared, such as industries, malls, marinas or train stations. These activities profit from the easy connection but create a barrier between the inhabitants and the sea. This research follows three aspects identified in a large variety of locations along the Mediterranean coast: longitudinal mobility, transversal accessibility and landscape discontinuities. The first territorial analysis defines a series of urban problematics classified by category. Then, the most representative case studies are developed by means of urban and architectural projects. The comparative analysis of these proposals provides a catalogue of design strategies which can be combined as criteria for solving multiple conflicts detected in the region. The result of this project is a methodology based on a matrix of general guidelines to ease the solving of local conflicts in a homogeneous way for the whole territory. The final aim is to re-establish order and continuity in the Mediterranean littoral skyline, fostering sustainable mobility and recovering public space for inhabitants. Full article

An urban riverway extraction method is proposed for high-resolution synthetic aperture radar (SAR) images. First, the original image is partitioned into overlapping sub-image blocks, in which the sub-image blocks that do not cover riverways are regarded as background. Sub-image blocks covering riverways are then filtered using the iterative adaptive speckle reduction anisotropic diffusion (SRAD) that introduces the relative signal-to-noise ratio (RSNR). The filtered images are segmented quickly by the Sauvola algorithm, and the false riverway fragments are removed by the area and aspect ratio of the connected component in the segmentation results. Using the minimum convex hull of each riverway segment as the connection object, the seeds are automatically determined by the difference between adjacent pyramid layers, and the sub-image block riverway extraction result is used as the bottom layer. The discontinuity connection between river segments is achieved by multi-layer region growth. Finally, the processed sub-image blocks are stitched to get the riverway extraction results for the entire image. To verify the applicability and usefulness of the proposed approach, high-resolution SAR imagery obtained by the Gaofen-3 (GF-3) satellite was used in the assessment. The qualitative and quantitative evaluations of the experimental results show that the proposed method can effectively and completely extract complex urban riverways from high-resolution SAR images. Full article

With the rapid expansion of impervious surfaces, urban waterlogging has become a typical “urban disease” in China, seriously hindering the sustainable development of cities. Therefore, reducing the impact of impervious surfaces on surface runoff is an effective approach to alleviate urban waterlogging. Presently, the development mode of many cities in China has shifted from an increase in urban scale to the improvement of urban quality through urban renewal, which is the current and future development path for most cities. Optimizing the design of impervious surfaces in urban renewal planning to reduce its impact on surface runoff is an important way to prevent and control urban waterlogging. The aim of this research is to construct an optimization model of impervious surface space layout under the framework of a geographic simulation technology-integrated ant colony optimization (ACO) and Soil Conservation Service curve number (SCS-CN) model (ACO-SCS) in a case study of Guangzhou in China. Urban runoff plots in the study area are divided according to the area of the urban planning unit. With the goal of minimizing the runoff coefficient, the optimal space layout of the impervious surfaces is obtained, which provides a technical method and reference for urban waterlogging prevention and control through urban renewal planning. The results reveal that the optimization of impervious surface space layout through ACO-SCS achieves a satisfactory effect with an average optimization rate of 9.52%, and a maximum optimization rate of 33.16%. The research also shows that the initial impervious surface layout is the key influencing factor in ACO-SCS. In the urban renewal planning stage, the space layout of the impervious surfaces with a high–low–high density discontinuous connection can be constructed by transforming medium-density impervious surfaces into low-density impervious surfaces to achieve the flat and long-type agglomeration of the low-density and high-density impervious surfaces, which can effectively reduce the influence of urban development on surface runoff. There is spatial heterogeneity of the optimal results in different urban runoff plots. Therefore, the policy of urban renewal planning for urban waterlogging prevention and control should be different. The optimized results of impervious surface space layout provide useful reference information for urban renewal planning. Full article

Recent progress and innovation are testament to the willingness of municipal authorities to address climate change. However, urban regions worldwide exhibit an immense diversity of conditions, capabilities and responses to the challenges of changing climatic conditions. While separated by politico-administrative borders, adjacent municipalities within such regions are connected through biophysical, politico-economic, and social systems likely to be reconfigured under changing climatic/environmental conditions. Yet, to date, politico-administrative borders have largely determined the parameters of local government climate change adaptation strategies, with insufficient attention to the role of inter-municipal collaboration, especially between neighbouring rural, peri-urban and urban municipalities, for co-ordinating such policies and interventions. Within a multi-level governance framework, this paper considers the recent evolution of climate agendas in the eThekwini (formerly Durban City Council) metropolitan municipality and the adjacent Ugu (predominantly rural) district municipality on the south coast of KwaZulu-Natal province (KZN), South Africa, focusing particularly on cross-border collaboration within the greater city region. The challenges were investigated by means of 53 in-depth, semi-structured interviews with municipal, regional and local authority association staff in November 2009, March 2012, and August 2017. Our core argument is that weak inter-municipal collaboration, particularly between urban, peri-urban and rural areas within metropolitan and functional city regions, has been a significant impediment to realizing transformative adaptation within such regions. The experiences of these two contiguous yet contrasting municipalities represent a microcosm of the dramatic discontinuities and inequalities on all variables within adjacent urban metropolitan and rural contexts in South Africa and beyond. Despite promising recent signs, the challenges of inter-municipal collaborative action are therefore formidable. Full article