Interpretation Of Satellite Images Research Articles

Slow surface subsidence and its impact on shallow loess landslides in a coal mining area

Surface subsidence caused by underground coal mining affects the hillslope stability conditions. However, few studies have focused on the coupling relationship between slow surface subsidence and landslide occurrences. A detailed landslide and fissure inventory in a coal mining area in Shaanxi Province, China, was produced based on interpretation of multitemporal satellite images and unmanned aerial vehicle (UAV) surveys. We used the interferometric synthetic aperture radar (InSAR) technique and landslide and fissure spatiotemporal statistics to investigate the spreading process of the slow subsidence caused by underground mining and examined its impact on the occurrence of shallow landslides. The InSAR results indicate that the actual extent of the subsidence zone is larger than the range of underground mining, which formed a subsidence basin along the coal mining panels. The subsidence curves go through initial, accelerative, and slow subsidence stages and characterized by S-shaped, which can be adequately fitted with logistic regression. Moreover, subsidence does not cease after the end of coal exploitation. Logistic models predicted that the duration of residual subsidence reached about 2–3 years. Subsidence significantly increased the likelihood of landslide occurrences. The spatial pattern of landslides is associated with the actual coal mining. We also investigated the clustering phenomenon of landslides and fissures under the impacts of subsidence. The frequency ratio of landslides and fissures increased with the cumulative subsidence. Finally, we propose a schematic view for landslides caused by coal mining and precipitation. This study will be helpful for elucidating the spatial–temporal evolution of slow subsidence and its impact on loess landslides in coal mining area.

Disturbances-based plan of delineating protected area’s buffer zone: A case study in Masigit Kareumbi Mountain, West Java, Indonesia

Abstract. Sumarga E, Swandhi I, Hairatunnisa, Susilowardani D, Nurrahman AY, Sadida A. 2021. Disturbances-based plan of delineating protected area’s buffer zone: A case study in Masigit Kareumbi Mountain, West Java, Indonesia. Biodiversitas 22: 5115-5122. The harmony between ecosystems and people, particularly those who live around and inside protected areas, is a key factor for the success of ecosystem protection. This subsequently will ensure the maintenance of ecosystem capacity in providing different types of services. Unfortunately, human activities are still commonly linked to different types of disturbances inside protected areas. This study aims to spatially analyze the anthropogenic disturbances inside a protected area, with a case study in Mount Masigit Kareumbi Protected Area, Indonesia. Two types of disturbances, which can be directly and indirectly related to human intervention, are analyzed, i.e., fires and encroachment for agricultural purposes. This study used Maximum Enthropy (MaxEnt) to analyze the risk of forest fire, while the encroachment was analyzed based on a combination of satellite image interpretation and direct field observation. Fire risk modeling performed well with a mean AUC of 0.98, estimating high fire risk (fire probability more than 0.5) distributed in about 109 ha area inside the Mount Masigit Kareumbi Protected Area. This study also identified about 428 ha of forest encroachment inside the protected area. This study further used the spatial information of the disturbances to determine the priority for selecting and designing areas for buffer zone development.

Application of Frequency-Resonance Methods of Satellite Images Processing for Hydrogen and Living Water Accumulations Searching Within Local Areas in Europe

The results of the application of mobile direct-prospecting technology of frequency-resonance processing and interpretation of satellite images and photo images at the sites hydrogen degassing in various regions are presented. Experimental reconnaissance studies were carried out to study the features of deep structure of the hydrogen degassing areas. The materials of instrumental measurements indicate that in regions of basalt volcano’s location with roots at different depths, signals at hydrogen frequencies are almost always recorded. When scanning the cross-section, responses from hydrogen are recorded from the upper edges of basaltic volcanoes to their roots. It can be assumed that basaltic volcanoes are a kind of channels through which hydrogen migrates to the upper horizons of the cross-section and further into the atmosphere. Within many basaltic volcanoes at a depth of 68 km, deep (living) water is synthesized. Hydrogen-rich water is curative and can be used for wellness purposes. All surveyed zones of longevity on Earth are located within basalt volcanoes, in which water synthesized at a depth of 68 km migrates to the surface and is used for water supply. Hydrogen deposits can be formed by basaltic volcanoes in adjacent sealed reservoirs. Within some survey areas, responses at hydrogen frequencies from limestones, dolomites and marls were recorded at shallow depths. Direct-prospecting technology can be used to study reservoirs in crystalline rocks (basalts including). Detailed studies and wells drilling in promising areas can be planned and carried out for hydrogen and living water at the same time. The result of investigation indicates the advisability of using direct-prospecting methods of frequency-resonance processing of satellite images to detect zones of hydrogen accumulation in areas of basalt volcano’s location, as well as in areas of hydrogen degassing. The use of mobile and low-cost technology will significantly speed up the exploration process for hydrogen, as well as reduce the financial costs for its implementation.

Slip Distribution and Footwall Topography of the Yanggao‐Tianzhen Fault (Northern Shanxi Graben): Implications for the Along‐Strike Variations in Fault Activity and Regional Deformation

AbstractSpatial patterns in fault activity were examined along the Yanggao‐Tianzhen Fault (YTF) in the northern Shanxi Graben, North China. First, we reconstructed the distribution of fault slips and quantified slip rates at seven sites along the fault, based on satellite image interpretation, field investigation, topographic surveying, and optically stimulated luminescence dating. The T3terraces and their contemporaneous alluvial fans with a best‐estimate age of 31.7 ± 1.4 kyr were used as strain markers to estimate slip magnitudes. We determined vertical slip and dip‐slip rates of ∼0.10–0.31 mm/yr and ∼0.11–0.37 mm/yr, respectively, at the surface. Assuming fault dips of 40 ± 10° at seismogenic depths, we predicted extension rates of ∼0.17–0.55 mm/yr. This suggests that at least 10% and up to 28%–54% (95% confidence interval) of the total extension of the northern Shanxi Graben is inhomogeneously partitioned by different sections of the YTF. We also evaluated the along‐fault relative tectonic activity by analyzing of five widely used geomorphic indices: hypsometric integral, basin elongation ratio, asymmetric factor, valley‐floor‐width‐to‐height ratio, and mountain front sinuosity. The determined fault slip rates and geomorphic indices demonstrate that the most prominent fault activity center occurred in the middle of the fault, and that fault activity wanes toward the fault tips. Moreover, the fault activity is highly heterogeneous and fluctuates along the fault strike, which may be attributed to either fault segmentation and linkage or the possible strike‐slip component of motion along the fault. Further exploration of fault kinematics and paleoseismic history is warranted.

Estimation of salt pond area in Madura based on satellite imagery

Salt is one of the essential commodities in Madura. Still, this commodity is often a problem related to the volume of production that cannot be determined with certainty. Sometimes, the estimation and actual production in the field is much different. The satellite image is a picture of an area photographed by satellite remote sensing of an area according to conditions in the field. Satellite imagery can be used to estimate the area of production of a commodity at a specific location. This study aimed to estimate the total area of salt pond in the Madura Island, specifically Sampang district, using a Landsat 8 satellite image. The method used spectral analysis that extracts multispectral data Landsat 8 to result from different areas. Field observations were conducted to validate the area. The results show that the accuracy of satellite image interpretation of salt ponds and non-salt ponds was 67.5%. Based on the result, it is possible to estimate salt pond area production in the Sampang district using Landsat 8. However, classification results must be improved by using other classification methods.

Assessment of Shoreline Transformation Rates and Landslide Monitoring on the Bank of Kuibyshev Reservoir (Russia) Using Multi-Source Data

This study focuses on the Kuibyshev reservoir (Volga River basin, Russia)—the largest in Eurasia and the third in the world by area (6150 km2). The objective of this paper is to quantitatively assess the dynamics of reservoir bank landslides and shoreline abrasion at active zones based on the integrated use of modern instrumental methods (i.e., terrestrial laser scanning—TLS, unmanned aerial vehicle—UAV, and a global navigation satellite system—GNSS) and GIS analysis of historical imagery. A methodology for the application of different methods of instrumental assessment of abrasion and landslide processes is developed. Different approaches are used to assess the intensity of landslide and abrasion processes: the specific volume and material loss index, the planar displacement of the bank scarp, and the planar-altitude analysis of displaced soil material based on the analysis of slope profiles. Historical shoreline position (1958, 1985, and 1987) was obtained from archival aerial photo data, whereas data for 1975, 1993, 2010, 2011, and 2012 were obtained from high-resolution satellite image interpretation. Field surveys of the geomorphic processes from 2002, 2003, 2005, 2006, 2014 were carried out using Trimble M3 and Trimble VX total stations; in 2012–2014 and 2019 TLS and UAV surveys were made, respectively. The monitoring of landslide processes showed that the rate of volumetric changes at Site 1 remained rather stable during the measurement period with net material losses of 0.03–0.04 m−3 m−2 yr−1. The most significant contribution to the average annual value of the material loss was snowmelt runoff. The landslide scarp retreat rate at Site 2 showed a steady decreasing trend, due to partial overgrowth of the landslide accumulation zone resulting in its relative stabilization. The average long-term landslide scarp retreat rate is—2.3 m yr−1. In 2019 earthworks for landscaping at this site have reduced the landslide intensity by more than 2.5 times to—0.84 m yr−1.

Mountain Landscape Dynamics after Large Wind and Bark Beetle Disasters and Subsequent Logging—Case Studies from the Carpathians

High winds and the subsequent infestation of subcortical insect are considered to be the most extensive types of large natural disturbances in the Central European forests. In this paper, we focus on the landscape dynamics of two representative mountain areas of Slovakia, which have been affected by aforementioned natural disturbances during last two decades. For example, on 19 November 2004, the bora caused significant damage to more than 126 km2 of spruce forests in the Tatra National Park (TANAP). Several wind-related events also affected sites in the National Park Low Tatras (NAPALT). Monitoring of related land cover changes during years 2000–2019 was based on CORINE Land Cover data and methodology set up on satellite and aerial images interpretation, on detailed land cover interpretation (1:10,000) for the local case studies, as well as on the results of field research and forestry databases. The dynamics of forest recovery are different in the clear-cuts (usually with subsequent tree planting) and in the naturally developing forest. The area in the vicinity of Tatranská Lonmnica encroaching on the Studená dolina National Nature Reserve in TANAP represents a trend of the gradual return of young forest. The area of Čertovica on the border between NAPALT and its buffer zone are characterized by an increase in clear-cut sites with potentially increasing soil erosion risk, due to repeated wind disasters and widening of bark beetle. Proposed detailed, large-scale approach is being barely used, when considering recent studies dealing with the natural disturbances.

Application of Earth Remote Sensing Data in the Practice of Hunting Design

According to the strategy for the development of the hunting economy in the Russian Federation until 2030, one of the principles of sustainable and rational hunting use is the monitoring of the resources used and a reliable assessment of the state of their habitat. The solution of modern problems of classification and typological assessment of the habitat of hunting animals is possible using multispectral satellite imagery, reflecting the whole variety of natural landscapes, types of vegetation and other properties of the earth’s surface. The article discusses the features of mapping the habitat of hunting animals using data from remote sensing of the Earth by classifying objects on satellite images according to various criteria corresponding to certain habitats of animals. Methods for interpreting satellite images for determining the categories and classes of the habitat of hunting animals are indicated, the results of a typological assessment of the habitat of hunting animals on the territory of the Priilmensky landscape of the Novgorod region are presented.

LATAR ALAM GEOMORFOLOGIS PERISTIWA PERANG GERILYA JENDERAL BESAR SUDIRMAN (1948-1949)

This study describes the geomorphological natural setting that became the guerrilla event of General Sudirman through literature studies, concepts, theories, and relevant previous research results. The study area of this research covers the central and southern zones of Java Island. The research analysis used descriptive analysis with the help of satellite image interpretation. This study indicates that the guerrilla route covers a geomorphological area that stretches across three provinces in Java Island. The geomorphological background is the karst landscape of Gunung Kidul and the volcanic slopes of Mount Wilis.

Mass movements susceptibility mapping by using heuristic approach. Case study: province of T\xe9touan (North of Morocco)

This research paper aims to model Mass Movements Susceptibility (MMS) in the province of Tétouan. First, we identified the characteristics and spatial mapping of the different types of MM (collapse, mudflows, and complex landslides) by means of the interpretation of satellite images and from fieldwork. Subsequently, we selected the predictive parameters controlling the occurrence of MM e.g. lithology, land use, fault density, hydrographic network density, slope degrees, slope aspects, and elevation. We used the heuristic method for Modeling Mass Movements Susceptibility (MMMS). The choice of this method compared to other methods (fractal, factorial, and neurons) is justified by the possibilities of intervention and the judgment of the expert who relies on the ground truth to select the parameters, to identify the classes, and to assign the weights to each one; unlike to other methods with steps that are done automatically and randomly. The results of the validation of the susceptibility map correspond to 70% compared to the field data and it includes five susceptibility classes (not susceptible, low, moderate, high, and very high). Indeed, the originality of this paper relies on the fact that the creation of our susceptibility map will eventually indicate the areas of roads, dwellings, the extension of urbanization, and dams, which are located in areas at risk of MM. Our map is also a powerful decision-making tool to conduct management plans and to guide the selection of sites to build new projects; which help mitigate the socio-economic impacts usually encountered when mass movements in Tétouan province are triggered.

Avoiding burning practice and its consequences on the greenhouse gas emission in sugarcane areas southern Brazil.

There is a growing need of sustainable solutions for balancing agricultural production with the reduction of its environmental impacts. The rapid increase in sugarcane cultivation and the progressive conversion of pre-harvest burning (BH) to green harvest (GH) have brought into debate the contribution of agricultural sector to the greenhouse gas (GHG) mitigation. This study focused on the estimated GHG emission from sugarcane cultivation during years in which sugarcane areas in southern Brazil expanded and passed throughout an important transition, from 2006 to 2012, when harvest adopted was changed from burned to not-burned based. Sugarcane management and harvest were mapped through visual interpretation of Landsat-type satellite images, and the areas under sugarcane cultivation were distinguished according to each agricultural phase and harvest regime (i.e., manual harvest with burning vs. green mechanized harvest). Based on a broad data review and applying the IPCC (2006) methodologies, the results were expressed in terms of kilograms of carbon dioxide equivalent (kg CO2eq ha-1). Avoiding burn prior to harvest, even during expansion of sugarcane areas, promoted a mean reduction of GHG emission from 901 to 686 kg CO2eq ha-1 relative to harvest phase (24% lower) and an increase from 1418.3 to 1507.9 kg CO2eq ha-1 related to the ratoon maintenance phase (6% higher). Analyzing the total GHG emission per unit of cultivated sugarcane area (hectare), it was observed a decrease from 2275 to 2034 kg CO2eq ha-1 (11% reduction). The gradual transition of pre-harvest burning on that period has contributed to the reduction of GHG emission associated with sugarcane production being an important step towards GHG mitigation while still providing more sustainable sugar and ethanol production in southern Brazil.

Structural Analysis and Morphotectonic Interpretation of Ain Sifni Anticline, Northern Iraq

Ain Sifni anticline is located in northern Iraq within High Folded Zone. It contains some tectonic deformations that need to study to determine the source and mechanism of these deformations concerning the geological setting of the study area. This study includes structural and morphotectonic interpretations for the Ain Sifni anticline, such as the visual & digital interpretation of satellite images and the Digital Elevation Model interpretation. These parameters are used to identify the morphogenic criteria and subsequently, to conclude a morphotectonic aspect of the deformations in the Ain Sifni anticline. Because of the regional tectonic evolution in this area, the structural and morphotectonic analysis of this anticline shows much evidence of morphological changes at the southeastern plunge area of the anticline within the Injana and Mukdadiya formations in comparison to the northwestern plunge area of the anticline. In addition, two recent water gaps have been recognized at the southeastern plunge area, one is confirmed and the other is proposed, and then a wind gap has been recognized in the middle of the anticline. A relation has been established between these morphotectonic features with the lateral propagation of the anticline towards the southeast, due to the regional tectonic deformation. A significant main fault has also been detected as a dextral strike-slip fault perpendicular to the fold axis of the anticline. This fault caused a difference in the vergency of the anticline and deformed the outcrops of formations in the study region.

Evaluation of the disturbance of forest ecosystems and their recovery after wildfire events in the Olekminsky reserve (Russia) using interpretation of Landsat satellite images

Evaluation of the disturbance of forest ecosystems and their recovery after wildfire events in the Olekminsky reserve (Russia) using interpretation of Landsat satellite images

Cenozoic tectono-geomorphic evolution of Yabrai Mountain and the Badain Jaran Desert (NE Tibetan Plateau margin)

Cenozoic tectono-geomorphic growth processes of the Yabrai Fault (YBF) along Yabrai Mountain (YM) and their impacts on the landscape formation of Badain Jaran Desert (BJD) during the late Quaternary are still unsolved, and yet are crucial to exploring the tectonic evolution of the boundary between the northeastern Tibetan Plateau and southern Gobi Alxa block. This study addresses these issues using information extraction-based interpretations of multiple satellite images coupled with field observations. The 138 km-long NE-NEE striking YBF can be divided into 3 segments: southwestern, central, and northeastern segments all characterized by left-lateral faulting with normal faulting components. Apatite (U-Th)/He thermochronology and calcite (U-Th) dating integrated with regional tectonic evolution history provides new geochronological evidence for understanding the multi-stage evolution of the YM and YBF. (1) Before the late Cretaceous (135–72 Ma), the mountain experienced rapid cooling and uplift. (2) During the late Cretaceous to Eocene (ca. 70–33.9), the YM is likely to have experienced denudation and flattening. (3) From the Oligocene to early Pliocene (33.9–5 Ma), the YBF underwent ~47 km of left-lateral displacement that accommodated the slip of Altyn Tagh Fault (ATF). (4) Since the Pliocene (5 ± 1 Ma), the YBF is characterized by left-lateral strike-slip faulting with a normal faulting component. The normal faulting resulted in uplift and the creation of topography along the central segment of the YBF. This has impeded the southeastward migration of sand dunes, building the world's highest megadune within the BJD. The tectono-geomorphic growth of the YM and YBF plays a key role in formation of the unique megadune-lake pattern and in preventing the merging of the BJD and Tengger Desert (TD).

Preservation of steppe landscapes in the structure of agrolandscapes of the Republic of Khakassia

The article presents the results of longstanding field studies (2000-2020) of steppe vegetation and demutation processes of fallow lands in the Altai region of the Republic of Khakassia. The aim of the work is to identify and determine the area of steppe landscapes and demutation areas in the structure of the lands of the Altai region. For this, a land use map of the Altai region was created, the areas of land occupied by steppe vegetation and fallow lands at different stages of restoration were calculated, demutational areas susceptible to overgrowing with trees and shrubs were identified. Based on geobotanical researches, cartographic materials, visual interpretation of Sentinel-2 satellite images of the visible L2A range (2018-2020), a GIS-project was created, including a cluster of raster data, thematic vector layers: water bodies, agricultural lands, vegetation, etc. It allows you to visualize information about the state and use of agricultural lands and vegetation in the form of maps of different thematic scope. It was searched out that the part of steppe landscapes in the total area of the Altai region is 32.2%. In the main, in arable sandy steppes that are not zonal for Khakassia have been preserved. True large bunchgrass and meadow steppes have been preserved in separate fragments and represent all stages of anthropogenous fracturing (various pasture modifications of these steppes). In the study area in the structure of agricultural lands 56860 hectares of agricultural lands belongs to abandoned lands at different stages of restoration, and only 20% postagrogenic lands of which are at the IV stage of restoration (compact-tussock or truly cespitous grasses). The process of restoration of steppe vegetation is accompanied by overgrowing with Ulmus pumila L.

Analisis Perubahan Penggunaan Lahan Kota Kupang Nusa Tenggara Timur Tahun 2010-2018

Urban land use is one of the important factors in urban environmental planning and modeling. Recent developments also show that Remote Sensing has been accepted as one of the main tools for information extraction and mapping. Extraction of land use information based on Remote Sensing includes visual interpretation and digital interpretation. This study aims to assess the ability of SAS Planet High Resolution Satellite Imagery in mapping land use, and obtaining information on land use changes in terms of the area and type of land use in the research area in 2010-2018. This research is focused in 3 (three) sub-districts in Kupang City. The reason for choosing the location is because observations show that there are many changes in land use, even areas that should not be used have experienced a touch of development. In addition, there are several educational centers, especially universities located in the area which tend to trigger land use changes. The research method used is survey method and data collection with SAS Planet Satellite Image Interpretation. The method of spatial analysis using GIS is by visual interpretation, digitization and overlay. Visual interpretation, digitization and overlay are used to determine land use changes that occur in the study area. The results in this study indicate that SAS Planet High Resolution Satellite Imagery can be used to identify land use information in Kupang City, because it can display objects more clearly, so that interpretation results can reach 90 percent accuracy and land use change analysis shows that within 8 years (2010-2018) there has been a significant change in land use where the built up land in the form of buildings, settlements and forests/mangroves has increased in area. Along with that, there is a reduction in the area of ​​use of grasslands and shrubs. Conversion of the fields also occurs in a moderate area. there was a significant change in which the highest land change occurred in the use of built-up land (buildings and settlements) and forests/mangroves, each of which experienced an increase of 108.45 ha (3.44 percent), settlements increased by 894.88 ha (27.50 percent) , and forest/mangrove area increased by 167.92 ha (5.16 percent).

An Overview of the Geomorphological Characteristics of the Pergamon Micro-Region (Bakırçay and Madra River Catchments, Aegean Region, West Turkey)

Current landforms are the basis for understanding past geomorphodynamics and human activities. Based on multiple materials and methods, including geomorphometric analyses of a digital elevation model and visual interpretations of satellite images, different landscape units of the Bakırçay and Madra River catchments in the environs of ancient Pergamon are described. The area was mainly shaped by tectonics that formed a horst-and-graben structure; small Miocene horsts and NE-trending subgrabens in the Kozak and Yunt Dağı Mountains were separated by the NEE-trending Plio-Pleistocene Bergama Graben. The asymmetry in relief, drainage network, and sediment accumulation between the Kozak Mountains to the north and the Yunt Dağı Mountains to the south of the lower Bakırçay plain characterize the Pergamon Micro-Region. The regional relief characteristics, with wide flat basin and plateau areas, are suitable for agriculture. Complemented by its richness in natural resources, the Pergamon Micro-Region became a preferred settlement area, with evidence of human impact since the Hellenistic–Roman period at the latest. As a consequence of settlement activities, several landscape engineering measures were implemented simultaneously with a parallel change in morphodynamics.

Land use/land cover dynamics and perception of the local communities in Bita district, south western Ethiopia

ABSTRACT Human settlements and swift expansion of agriculture have simplified the natural ecosystems and causing the loss of copious biological diversity. The current study was conducted in Bita district, southwestern Ethiopia to examine the pattern of land use/land cover (LULC) dynamics using multispectral satellite data for the years 1973, 1986, 2000 and 2018. The remote-sensed data were processed using ERDAS imagine 2014, ArcGIS map 10.5, and ENVI software. A supervised maximum likelihood classification algorithm was employed along with the visual interpretation of satellite images to classify each Landsat image into LULC categories. Semi-structured interviews and Focus Group Discussions were employed to identify major driving forces, impacts, and periodic LULC changes. The result revealed an alarming decrease in forestland but with an increase in the cropland. During the study periods, cropland, bareland and settlement areas have augmented by over 450% each. Conversely, grasslands and forestlands have reduced by over 45% each. The local communities perceived the population growth, and the expansion of coffee plantations and other croplands as the dominant drivers of LULC changes. The respondents also observed that the decline in forest cover triggered the loss of biodiversity, soil fertility and water availability. Decision-making on issues related to natural resource conservation, utilization and participatory resource management has to involve the engagement of the local community and other stakeholders. The deterioration in ecosystem services such as lack of benefits from medicinal plants from the forest, increase land degradation, and the decrease in water availability found to be the impacts of LULC change. This calls for a proper natural resource management plan and improvement in the livelihood of the community in the study area.

Multidecadal biogeomorphic dynamics of a deltaic mangrove forest in Costa Rica

Térraba-Sierpe National Wetland (TSNW) is the largest wetland in Costa Rica located in the southeastern part of the country. The protected area comprises the Térraba-Sierpe delta covered with dense mangrove vegetation. We aim to analyze the geomorphological evolution of the coastal bars and the land use/cover change between 1948 and 2012 using aerial photographs and satellite images interpretation as well as field corroboration. We determined the geomorphological dynamics of three coastal bars (supratidal, intertidal, and subtidal), ten land uses/covers, and deforestation rates of six delta mouths for 64 years. In addition, we estimated a net periodic loss by deforestation between 1948 and 2012 exceeding 2562 ha, with an annual net loss of 40 ha per year. Moreover, these outputs quantify the anthropic impact over 40 years and give good evidence from an example of environmental policies implementation since the 1990s to protect these fragile tropical ecosystems.

Using a transect-focused approach to interpret satellite images and analyze shoreline evolution in Haiyang Beach, China

This paper devises a set of simple and practical method for interpreting hundreds of free medium-resolution satellite images to study beach evolution. The method focuses on beach transects, integrates the computer-aided and subpixel recognition technologies, and derives multiple shoreline indicators and historical beach profile shape. This paper also introduces how to use the method with a case study. The case study uses 880 Landsat images from 1984 to 2020 to examine the historical evolution of the complex Haiyang Beach in China as well as its responses to onshore and offshore engineering projects.The results not only show the detailed temporal and spatial changes of the upper beach based on dry/wet and high-water lines, but also the changes of the middle and lower beach based on mean-water, low-water, and low boundary lines, as well as the changes of beach profile shape, beach slope, and intertidal width. The random errors of the dry/wet, high-water, mean-water, and low-water lines are 7.8 m, 10.5 m, 15.9 m, and 19.2 m, respectively. The random errors not only result from the geo-reference process of satellite images and the recognition process of shoreline positions, but are also affected by random water level fluctuations and irregular undulations of the beach profile. This paper also discusses the similarities, differences, and applicability of these shoreline indicators. It is found that the evolution of dry/wet and high-water lines are similar and mainly affected by onshore engineering projects while the evolution of mean-water, low-water, and low boundary lines are similar and mainly affected by offshore engineering projects.The method provided in this paper can comprehensively evaluate beach evolution based on free satellite images, and would be helpful for understanding and protection of the beaches affected by intensified or intensifying engineering projects and human activities.