Aerial Photographs Research Articles

SEGMENTATION OF PARCEL BOUNDARY INDICATIONS IN VERY HIGH-RESOLUTION ORTHOPHOTO MOSAICS FOR CONTROL POINT IDENTIFICATION

Several Land Parcel Geometry issues in Indonesia's Land Registration Process, such as parcel overlapping, gaps between parcels, and incorrect parcel shapes and sizes, are currently being addressed through a block adjustment approach. One crucial aspect of the block adjustment process is determining control points that tie the parcel geometry to the land coordinate system. Detailed Observations and measurements of parcel points in the field and aerial photographs established these control or tie points. Rectifying land parcels requires many control points, requiring substantial time and effort. The automation phase is critical to expedite the control point identification process. This research uses artificial intelligence techniques to identify control points in very high-resolution orthophoto mosaics. The method employed for control point identification involves the Segment Anything Model (SAM) algorithm to segment parcel boundary indications accurately. Enhance the quality of segmentation results conducted by fine-tuning, followed by centerline extraction and refinement of the extracted data. Based on the segmentation, a SAM model capable of accurately segmenting building objects is attained, After the centerline extraction process and modifications to the existing geometric operations within the GIS Tool, at the edges of buildings, fences, and walls derived points. These points can serve as control point indications in the block adjustment process.

UAV Mapping for Flood Routing in Steep and Densely Vegetated Areas: Insights from the Contok River Basin, Garang Watershed, Indonesia

This research utilizes photogrammetry to assess flood routing dynamics in the Contok river basin, a sub-watershed with a challenging landscape characterized by steep slopes, dense vegetation, and meandering patterns. The objectives are to assess Unmanned Aerial Vehicle (UAV) mapping accuracy, evaluate the river's capacity for design flood volumes, quantify the impact of land cover changes on surface runoff, and provide insights for early warning systems and watershed conservation strategies. The study area, encompassing the Contok River Basin, a sub-watershed of the Garang Watershed, covers 7,413 km² and includes a stream length of 5,274 meters in Semarang City, Central Java, Indonesia. This research employed image processing of aerial photographs and satellite imagery. Aerial photos captured using UAV data were utilized to derive elevation data and cross-sectional profiles of the Contok River, essential for understanding channel morphology and hydraulic characteristics. Concurrently, satellite imagery was used for land cover analysis, identifying vegetation and built-up areas that influence surface runoff dynamics. Hydrological analysis was performed to quantify discharge magnitudes, simulated against river cross-sections to evaluate flood behavior under varying scenarios. Our proposed UAV mapping provides adequate accuracy for small and local areas. Furthermore, it remains reliable for flood routing analysis. We discovered that the capacity of the Contok River channel in the downstream area allows it to convey design flood discharges up to a 50-year return period, contrary to the upstream area, it overflows. Notably, the shift from vegetated to built-up and agricultural areas significantly contributes to the 10.6% increase in surface runoff. This research highlights the role of UAV-based photogrammetry in assessing and mitigating flood hazards amidst evolving land cover patterns. It also enhances the understanding of flood dynamics and thus provides insights that will serve as a reference for flood early warning systems, flood management practices, and watershed conservation.

ANALISIS POLA PERUBAHAN LAHAN SAWAH MENGGUNAKAN SISTEM INFORMASI GEOGRAFIS (STUDI KASUS: KELURAHAN MAKROMAN, SAMARINDA)

Changes in rice fields are an important phenomenon that affects the sustainability of agriculture and the environment. This study aims to analyze the pattern of changes in rice fields in Makroman Village, using a Geographic Information System (GIS) approach. The method used is spatial analysis which involves such as spatial data creation, spatial data conversion, spatial data clustering, and mathematical calculation of spatial data. The spatial data used in this study include Ikonos Satellite Images of Makroman Village in 2011 and UAV Aerial Photos of Makroman Village in 2019. The results showed that the area of rice fields in Makroman Village increased from 96.196 ha to 129.343 ha in 2011-2019. Spatially, the increase occurred due to the presence of new rice fields and existing rice fields that did not decrease in number. Shrubs become land uses that have the potential to be converted in rice field extensification activities. GIS application is a method that can be used to answer the problems in this study to the level of detail, but some things that need to be considered in the application of this method are the quality of spatial data, especially remote sensing data used.

Utilization of the DJI Phantom 3 Advance Quadcopter Type Drone Vehicle for Area Mapping of the Samarinda State Agricultural Polytechnic Campus

This research is motivated by the fact that currently remote sensing technology continues to develop, both in terms of data collection and processing. This is characterized by the existence of data collection techniques using unmanned aerial vehicles for aerial photo mapping. The advantage of using this technology is that it is effective and efficient both in terms of time and human resources for mapping in areas that are not too large. Another advantage is that it can produce clearer photos, because the plane's flying height is below 400 meters above ground level so that during the shooting process there is no cloud interference. The aim of this research is to create an aerial photo map at the Samarinda State Agricultural Polytechnic, validate objects in aerial photos and in the field, and provide information about the area, boundaries and topography of the Samarinda State Agricultural Polytechnic campus area. The implementation of activities and research objects is the Samarinda State Agricultural Polytechnic campus area. This research uses a small format aerial photo mapping method using a Quadcopter, making it easier to determine where to start taking off and landing. With a Quadcopter vehicle, grounding problems are no longer an obstacle. The research results showed that photography carried out with a Quadcopter at a height of 200 m above the ground produced an area of 28.17 Ha and a spatial resolution of 8.40 cm/pixel. The validation results in aerial photos and in the field using drones have a small difference between 0-4 cm with an average of 1.625 cm/photo. From the digitization results of campus objects, there are 30 objects on campus with a total area of 2.67 Ha. As for the topography results in the campus area, the highest point is 107.5 meters above sea level and the lowest point is 60 meters above sea level.

Оценка развития опасных склоновых процессов и явлений в районе проектирования и строительства всесезонного туристско-рекреационного комплекса «Мамисон»

This paper presents the ortho-photomap we created of the territory of the all-season tourist and recreational complex “Mamison” (ATRC “Mamison”) using the example of the Kozy-Don gorge, which was obtained using a DJI Mavic Air 2 unmanned aerial vehicle. The compiled ortho-photomap of the Kozy-Don gorge quite fully displays the terrain, which made it possible to create a DTM (digital terrain model) with a given image scale. Using DTM, areas of development of dangerous slope processes, such as avalanches, mudflows, etc., were identified. The data obtained with the help of UAVs are already being used for the research and development of mountainous areas, and are also taken into account in the design and construction of national economic facilities of the Mamison ATRC. Materials and methods. In this work, the creation of an ortho-photomap of the Mamison territory is shown using the example of the Kozy-Don gorge, where mudflow and avalanche activity is widespread. During the field work, aerial photography of the gorge’s relief was taken for further image processing in the Agisoft Metashape Professional software package. Results. About 1000 photographs were taken, of which 952 were aligned. Based on the aligned photographs, more than 551 thousand tie points were automatically constructed, reflecting relief characteristics. Based on the aligned photographs, more than 551 thousand tie points were constructed, reflecting relief characteristics. A denser cloud of points was built to clarify the characteristics of the relief; as a result of processing, a clearer relief model was obtained. Based on a dense point cloud, a digital model of the study area was built, with the relative heights of the Kozy-Don gorge. Using the resulting DTM, a map of average relief slopes was constructed, which was necessary to determine avalanche danger zones. Also, based on the DTM, an ortho mosaic was built for the territory of the Kozy-Don gorge. Discussion. During the field work, the Kozy-Don gorge was examined on the territory of the All-Russian Technical Complex. Aerial photography of the gorge’s relief was taken for further image processing in the Agisoft Metashape Professional software package. 194 photographs were taken. The photo database was created using the standard shooting equipment of the DJI Mavic Air 2 unmanned aerial vehicle. Based on the results of photo processing using software, an orthomosaic map was constructed for the territory of the Kozy-Don gorge of the Mamison ATRC. Conclusions. The created ortho-photomap of the Kozy-Don if ATRC “Mamison” quite fully reflects the topography of the study area. It allows you to select individual areas in the form of a 3-model with a given image scale. Resume. Based on aerial photography, a digital terrain model with relative heights is built. It allows you to select and form, in the form of a separate file, areas of development of dangerous slope processes – avalanches, mudflows, landslides. Suggestions for practical applications and directions for future research. The research results obtained using an unmanned aerial vehicle can be useful in the exploration and development of mountainous areas, especially where the terrain is difficult to pass and where stationary research is not conducted.

On the Methodology of Analysing Aerial and Satellite Images to Detect Archaeological Sites

Today, the use of remote sensing methods is an integral part of archaeological research. The use of various types of aerial and satellite photography at the level of micro-regions makes it possible to collect data on large areas in a short time. The received data are subject to archaeological deciphering – the process of recognition, detection and interpretation of archaeological information based on photographic images of the Earth’s surface. In the course of deciphering pictures, photographic images of objects are analysed, which have a number of decipherable features, that is, characteristic ones by which archaeological objects can be recognised. Modern processing and recording of these data is carried out in geoinformation systems, taking into account their spatial reference. The analysis of domestic publications showed that this direction is promising for future research in Ukrainian archaeology. However, the researchers do not provide a general, clear methodology for working with aerial photography materials and features of archaeological deciphering. Summarising this information prompts the creation of a consistent description of such work. This description is intended to formalise those research operations, which in one way or another were performed by the above-mentioned authors. The paper is an attempt to create a methodology for the archaeological deciphering of aerial and satellite photos for the remote study of archaeological monuments and the protection of archaeological heritage. It is intended to summarise the previous experience of publishing the methodology of working with remote sensing of the land in the archaeology of Ukraine and to structure it on the basis of our own developments. The proposed scheme is not final or mandatory, but only offers one of the options for the approach to thematic deciphering in archaeology. Undoubtedly, the given algorithm of actions will require improvement and expansion as a result of the accumulation of practical experience and theoretical achievements. It is important to emphasise that this branch of archaeology is closely related to technical sciences and technologies in general and therefore requires thoughtful introspection and competent theorising. To obtain reliable results of deciphering in archaeology, it is necessary to always pay attention to the analysis of the research process and the multi-level process of checking its results. The reliability of the obtained data definitely depends on the clarity and awareness of the sholar’s actions, which in turn has a great impact on various fields of archaeological science, and even national security. The reliability of data depends on the “purity” of research operations, which is extremely important in the process of monitoring archaeological objects. The current state of archaeological monuments in Ukraine in the conditions of martial law, and especially on the territories of hostilities, requires urgent monitoring. With the help of modern aerial and satellite photographs, it is especially relevant and necessary today to investigate the damaged archaeological landscapes, wide application of remote sensing of land, satellite navigation systems and geo-information technologies with decoding, for the collection, processing and analysing the information in combination with the data of specific aerial visual surveys using drones and traditional methods of surveys in those areas where it is possible.

Evolution of flight control systems and aerial photography in unmanned agricultural aircraft

The advancement of UAV technologies has enabled the automated capture of photos and videos, eliminating the need for manual intervention in flight control. (Research purpose) This research aims to conduct a retrospective analysis of the evolution offlight control systems and the development of aerial photography equipment for agricultural land, covering the period from the mid-19th century to present. (Materials and methods) A systematic literature review was conducted using the historical-analytical method. The paper examines original works by both domestic and international authors, including monographs, scientific journals, conference proceedings, museum exhibitions, photographic archives, and open-source software code. (Results and discussion) The paper identifies six distinct phases in the development of aerial photography and flight control systems. The classification is based on key innovations in camera types, control systems, and aircraft designs. Each phase highlights the predominant cameras, control systems, and aircraft utilized for agricultural applications. (Conclusions) Over the past 165 years, notable changes have occurred in aerial photography parameters, including the type of photographic material, image spatial and spectral resolution, camera weight and mounting, shutter types and their mechanisms, inertial control units, integrated GPS/GLONASS receivers, and light sensors. In terms of flight control systems for UAVs, significant developments over the last 106 years include variations in flight control types, the number offlight-stabilizing sensors, obstacle detection systems, size of the flight control units, flight modes, and takeoff/landing techniques, along with interfaces for attachments. It is anticipated that future intellectualization and miniaturization of flight control systems will not only boost UAV performance but also reduce the economic costs associated with the aerial monitoring of agricultural biological assets.

Unveiling Deep-Seated Gravitational Slope Deformations via Aerial Photo Interpretation and Statistical Analysis in an Accretionary Complex in Japan

The objective of this study was to identify the locations of deep-seated gravitational slope deformations (DGSDs) and define the numerical characteristics of these deformations to contribute to the sustainable management of social infrastructure in the event of an increased disaster. The topographic features of the DGSDs were quantitatively characterized based on their surface morphologies. Topographic features indicative of gravitational deformation in pre-slide topographic maps, such as terminal cliff failures, irregular undulations, and gullies, suggest that progressive deformation occurred over a prolonged period. To track the gravitational deformation over time, we interpreted aerial photographs of DGSDs from 1948 and 2012 associated with deep-seated landslides on the Kii Peninsula induced by Typhoon Talas on 2–5 August 2011. Corresponding numerical analysis of the gravitational deformations using 1 m digital elevation models reveals that landslide areas exhibit eight characteristic influencing factors, demonstrating that characteristic morphologies exist in areas that eventually experience landslides. One such morphological feature is the existence of a gently sloping area in the upper section of the deep-seated landslide mass, which comprises a catchment basin without a corresponding valley or gully. These findings suggest that rainwater penetrates the ground, and degrades and deforms the rock within the landslide mass, causing the slope to fail after torrential rainfall. This study holds great significance for advancing sustainable infrastructure development and management and mitigating environmental changes.

Analiza strukturalna i zróżnicowanie pegmatytów w starożytnym twierdzeniu, Giraúl IV, dystrykt pegmatytów Namibe, Angola

Since the early 60´s, in the past XX century, the Giraúl pegmatites have been known for their resources of beryl, mica and feldspars, which were exploited in a regular basis from Giraúl claims I to IV till 1974, during the Portuguese administration of Angolan territory. A broader exploration of this pegmatite field was performed by the ancient Lobito Mining Company (LMC) engaged in detailed geological mapping of the granitic pegmatites and the structural constraints of their location. A structural map of the region was than elaborated, combining the interpretation of aerial photographs with field work performed by the LMC geologists. Recently, a growing economic interest is attributed to these claims, in the region of Bulamucolocai, Pitau and Muvero desert-dry rivers (locally known as “Mulolas”), considering the Li, Cs, and Ta (LCT) metallic specialization of some pegmatite bodies and the occurrence of beryl and tourmaline gemstones, mainly, morganite (Cs-beryl), aquamarine and also elbaite-liddicoatite. Giant crystals of spodumene, up to 6 m in length, define individualized quartz + spodumene units inside some of the more typical LCT pegmatite bodies. Pollucite was identified in the main pegmatites of Giraúl IV claim and not in the adjacent igneous leucocratic breccias. These, in turn, correspond to a complex pegmatite assemblage, very peculiar in what concerns its selective metasomatic effect over some surrounding rocks, with the formation of rims of holmquistite amphibole in contact with gabbro and norite and schorl-dravite tourmaline in contact with gneissic to metapelitic hosts. The breccia-like granitic rock combines clasts of spodumene an K-feldspar with a matrix mainly composed of some quartz, albite and mica including tourmaline, garnet and F-apatite, as accessory minerals. In the same area, huge potassic pegmatites hold giant crystals of microcline and orthoclase and very little quartz, being unusual due to its high content of triplite – zwieselite and triphylite – lithiophilite primary phosphates. The overall composition of these pegmatites is more likely syenitic (low quartz content) than truly granitic. A high-resolution structural analysis of the LCT ensemble (pegmatite plus related lithotypes) is now proposed enhancing the unusual relations between granite breccia plugs, sill-like more typical pegmatites, irregular shaped isodiametric bodies and products of metasomatism. This approach will lead to the understanding of the true dimension, anatomy and inner fraccionation of the different LCT facies and rare-metal deposits with obvious consequences regarding mineral detection and resource – reserve estimation, through the proposal of a more suitable conceptual model to rule its exploration.

Application of unmanned aerial vehicle tilt photography technology in geological hazard investigation in China

Application of unmanned aerial vehicle tilt photography technology in geological hazard investigation in China

The Chaochou active fault in southern Taiwan: Characteristics and geomorphological significance as a reverse fault

The Chaochou Fault in southern Taiwan has long been recognized as an active fault, but its exact location is still uncertain. In this study, we focused on the middle part of the Chaochou Fault, where a flight of fluvial terraces was deformed and preserved. High-resolution aerial photos were first used to observe and map these terraces and their vicinity, followed by comprehensive field investigations including RTK-GPS surveys for high-resolution topographic profiles of the deformed terraces and OSL sample collections for obtaining the ages of the terraces. A series of active faults, consisting of Fault A (“FA”), Fault B (“FB”), and Fault Bb (“FBb”), are collectively named the Chaochou Active Fault Zone. The fault zone is recognized and characterized by range-facing scarps, frontal flexural scarps, and discontinuous slopes deformed by FA, FB, and FBb, respectively. The repeated activities of FA were recorded by the incremental fault scarp heights from young to old terraces. Considering the highest fault scarp height of 65.9 ± 6 m observed in T1 and its OSL age of 35.3 ± 4.3 ka, the long-term fault slip rate of FA is about 2 mm/yr.

Aerial photo database model of Indonesia's national territory in a Geospatial intelligence perspective

Aerial photo database model of Indonesia's national territory in a Geospatial intelligence perspective

High-resolution mapping of tree species and associated uncertainty by combining aerial remote sensing data and convolutional neural networks ensemble

Mapping tree species diversity is essential for monitoring and managing forest ecosystems. Automating ecoforestry mapping using remote sensing images remains an important challenge due to the tremendous variability in forest covers and the conditions under which images used for classification are acquired. Deep learning algorithms have been increasingly used over the last few years to analyse remote sensing data for mapping tree species. However, most of these studies focus only on a small number of species or a limited area and avoid providing a spatially explicit representation of the uncertainty related to the predictions, rendering them unsuitable for operational use.In this study, we used an ensemble of convolutional neural networks to map forest species and land cover types across a 10,000 km2 area in Quebec, Canada, spanning mixed and boreal forests. We built a georeferenced label database to train and test nine models, which resulted from the combination of three training datasets and three-commonly used convolutional neural network architectures (VGG16, ResNet50v2, Densenet121). These models were trained on multiband aerial photographs and a canopy height model derived from airborne lidar point clouds and used to map the diversity and distribution of tree species and land cover types. The level of agreement among models was used to generate uncertainty maps. The performance of the super-ensemble using 1311 independent forest inventory plots and assessed the extent to which uncertainty maps could serve as a spatially explicit indicator of model performance.The super-ensemble achieved 90% global accuracy. Our results indicated that the performance of the super-ensemble surpassed that of all individual architectures while also showing a positive effect of the canopy height model on performance. The comparison of the super-ensemble map with the proportion of basal area measured in forest inventory plots confirmed the reliability of the model over the study area. Our results also indicated that mapping the inter-model agreement provides a reliable spatially explicit estimate of model performance. The robustness and reliability of the proposed approach support its use in an operational context while also providing a conceptual framework to evaluate the reliability of uncertainty maps.

Research on Evaluating the Characteristics of the Rural Landscape of Zhanqi Village, Chengdu, China, Based on Oblique Aerial Photography by Unmanned Aerial Vehicles

To achieve the transition of rural areas from traditional to modern, the visualization of rural landscape data and feature evaluations are essential. Landscape character assessment (LCA) is a well-established tool that was developed to assess and understand rural landscape features. In recent years, drones have become increasingly attractive for various applications and services due to their low costs and relative ease of operation. Unlike most previous studies that relied solely on drone-based remote sensing or visual esthetic evaluations, this study proposes an innovative assessment method based on landscape characteristic assessment (LCA) and oblique drone photography technology, supported by specific data and survey results. These include various landscape metrics, such as the Shannon diversity index (SHDI), Shannon evenness index (SHEI), vegetation coverage, landscape character zoning, and delineations of various ecologically sensitive areas. This method was applied to study Zhanqi Village in Chengdu, Sichuan Province, China and revealed some unique characteristics of this village. By categorizing and describing the landscape features, the study makes judgments and decisions about them. This is a beneficial attempt to apply the scientific methods of landscape assessments to the production management of aerial drone surveys. This method provides a comprehensive framework for evaluating rural landscape features and demonstrates that the combination of LCA and oblique drone photography technology is feasible for rural landscape research. Additionally, this study emphasizes the need for further research to explore the potential application of this method in continuously evolving urban and rural environments in the future.

Mountain search and recovery: An unmanned aerial vehicle deployment case study and analysis

AbstractMountain search and rescue (MSAR) seeks to assist people in extreme remote environments. This method of emergency response often relies on crewed aircraft to perform aerial visual search. Many MSAR teams use low‐cost, consumer‐grade unmanned aerial vehicles (UAVs) to augment the crewed aircraft operations. These UAVs are primarily developed for aerial photography and lack many features critical (e.g., probability‐prioritized coverage path planning) to support MSAR operations. As a result, UAVs are underutilized in MSAR. A case study of a recent mountain search and recovery scenario that did not use, but may have benefited from, UAVs is provided. An overview of the mission is augmented with a subject matter expert‐informed analysis of how the mission may have benefited from current UAV technology. Lastly, mission relevant requirements are presented along with a discussion of how future UAV development can seek to bridge the gap between state‐of‐the‐art robotics and MSAR.

Analysis on the mechanism and dynamics of frequent debris flows in typical alpine gorges areas—a case study of Yizhong river in Deqin County, Yunnan, China

Debris flow is a common geological disaster in mountainous areas, which occurs frequently in the rainy season and has strong mobility and destructiveness, often bringing serious loss of life and property. Previous studies have focused more on single outbreaks of debris flow disasters, and less on multiple outbreaks of debris flow disasters in the same gully during the rainy season, which makes it more difficult to carry out prevention and control work for similar disasters. Because the occurrence of the disaster has its corresponding geomechanical model as the basis, which provides the necessary scientific basis for the prevention and control of the disaster. Through data collection, field investigation, drone aerial photography, modelling and rainfall data analysis, the geological environment of Yizhong River Basin and the frequent occurrence mechanism of debris flow disasters were investigated, and a conjugate shear-type disaster-inducing geomechanical model was proposed. With the help of RAMMS numerical simulation software, the dynamic mechanism of the disaster threatening the life and property safety of the residents in Deqin County was analysed to provide the necessary scientific basis for the prevention and control of the Yizhong River debris flow disaster. Base on the characteristics of the geological environment in alpine and gorge areas, the necessity and advantage of applying the nap-of-the-object photogrammetry technology to engineering geological survey in alpine and gorge areas are put forward.

Research on semantic segmentation algorithm of high latitude urban river ice based on deep transfer learning

ABSTRACT Automated observation methods for monitoring river ice in high-latitude urban areas are crucial for resource utilization, risk assessment, and navigation. However, current research lacks actual-scale river ice classification, such as low-altitude surveys. This study established a dataset of river ice in the Songhua River near Harbin, Northeast China, using UAV aerial photography and applied the RININet semantic segmentation algorithm for precise classification of different ice types in low-altitude aerial remote sensing images. To address environmental challenges, a feature extraction method integrating channel and spatial attention mechanisms was adopted, along with an improved pyramid pool structure to enhance feature recognition. Additionally, a two-stage transfer learning method established an ice recognition database, overcoming issues like small data volume and high annotation costs. Comparative evaluation metrics demonstrated the high accuracy of the semantic segmentation framework. Furthermore, a method for estimating ice blockage risk was proposed, applicable to various urban river ice management tasks, with practical significance.

Unraveling the role of dextral faults in the formation of pull-apart basin structures and their implications on the genesis of ophiolites and pluto-volcanics

Rhombic structures have been observed in the Qom-Zefreh-Nayin-Dehsheir-Baft region, specifically along the direction of the dextral faults, which have caused significant changes in strike length. This study investigates the geological features and fault interactions in the region through the examination of aerial images, fault-lithology correlations, petrology, crustal thickness, and seismic studies. The analysis of aerial photos and geological correlations revealed the presence of ophiolites and pluto-volcanics associated with faults and rhombic structures. By conducting field geology and combining various geological studies, a pull-apart basin was identified in the area, contributing to the formation of three rhombic structures. This basin played a crucial role in the genesis of the region’s ophiolites and pluto-volcanics. The research suggests that the initial tensional stress leading to the pull-apart basin was caused by the right step of a dextral fault within the Urumieh-Dokhtar magmatic arc. This fault formation occurred due to the oblique Arabian subduction towards the Iranian plateau. During the Zagros orogeny, the stretched area persisted, leading to the formation of oceanic crust in this location. The subduction angle changes from subduction to super-subduction, resulting in the classification of the region into two types: C and E genes. Different types of magma, including alkaline, subalkaline, shoshonite, calcalkaline, and adakitic, were identified in this region. The study highlights the significance of tholeiitic arcs, abyssal features, crust thickness, and seismicity in understanding oblique diagonal subduction models and tensional pull-apart basins, which are crucial in the transition from subduction to super-subduction. This research offers valuable insights into the geological complexities of the region and opens up opportunities for further exploration of similar models.

The effect of pre- and post-processing techniques on tree detection in young forest stands from images of snow cover using YOLO neural networks

A neural network model for individual tree detection was developed based on the YOLOv4 architecture, which underwent additional preprocessing and postprocessing steps. The preprocessing step involved expanding the dataset by randomly cutting fragments from images, calculating anchor frame sizes using the K-means clustering algorithm, and discarding anchor frames that were too small a priori. The existing post-processing block of the YOLO architecture was modified by giving more weight to false positives in the error function and using the non-maximum suppression algorithm. Baseline neural networks from the YOLOv4 and YOLOv5 architectures, each in two versions (pre-trained and not pre-trained on the MS COCO dataset), were used for comparison without any additional modifications. In the overgrown experimental field, multi-season aerial copter surveys and ground counts were conducted on several sample plots to gather data. Comparison of multi-season aerial photographs with ground-count data showed that the best images in terms of the percentage of visually identifiable trees were those taken during the snowy season and when there was no foliage. Using these images and some additional images, we manually created a dataset on which we trained and tested neural network models. The model we developed showed significantly better results (2 to 10 times better) on the mAP 0.5 metric compared to the alternatives we considered.

Assessing geomorphological changes in coastal lagoon inlet using geospatial tools: A case study Moulay Bousselham lagoon, Morocco

Coastal monitoring is crucial for coastal management and both sustainable progress and environmental protection. This study aims to assess the morphodynamic changes undergone by an inlet, sandpits, and adjacent beaches of Moulay Bousselham lagoon (Morocco Atlantic coast), considered a RAMSAR site of significant biodiversity. Firstly, a Digital Shoreline Analysis System (DSAS) is applied to monitor shoreline evolution between 1949 and 2021, based on the End Point Rate (EPR) and Linear Regression Rate (LRR) methods, with the study area divided into south and north sides. Secondly, we mapped sandpit areas in the lagoon using recent satellite images and historical aerial photos covering a period of 75 years (1949–2024) within a GIS (Geographic Information System) environment. As a result, the average annual accretion rates on the north side, comprising 735 transects (1.45 km length), are +3.23 m/year (EPR) and +3.26 m/year (LRR). Additionally, the accretion phenomenon is observed in 117 transects, while erosion is recorded in 618 transects with −0.73 m/year and −0.81 m/year for EPR and LRR methods, respectively. The south side, comprising 1085 transects (2.46 km length), shows average annual erosion rates of −0.99 m/year (EPR) and −0.76 m/year (LRR) concerning the south part of the entrance inlet, with 278 transects showing accretion and 807 transects indicating erosion. Moreover, flood-dominated deltas (sandpit) mapping shows significant changes in the sandpit areas at the entrance inlet and inside the lagoon, with the area of accumulation increasing from around 155662,57 m2 in 1949 to 306020,22 m2 in March 2024. Inlet width measurements reveal fluctuations over time, from 53 m in 1949 to 177 m by 1988, reflecting dynamic coastal processes. However, by March 2024, the width decreased to 30 m, indicating sediment blockage and intense siltation. This analysis revealed that these sedimentation trends are mainly controlled by southward-directed littoral transport and the change in inlet position induced by several factors, including tidal currents, wave energy and river flow, particularly during winter seasons and extreme events (marine submersions and flooding). This article will help us to understand the relationship between the evolution of the coastline and its immediate influence on sediment supply to the lagoon.