Archival Satellite Images Research Articles

Historical Narratives and Spatial Strategies of Reappropriation in Three Romanian Orthodox Monasteries

Contrary to the abundance of shared religious places throughout south-eastern Europe, multi-religious interaction is not a regular feature in Romania. Pilgrimages and visits to the popular Orthodox monasteries of Prislop and Nicula in Transylvania and Dervent in Dobruja are an exception to this trend. Unsurprisingly, these two regions are historically characterized by a remarkable ethnic and religious diversity. The two Transylvanian monasteries attract practitioners of different Christian denominations (Orthodox, Greek-Catholic, Roman-Catholic and Evangelical), while Dervent is a devotional site for Christians and Muslims (Tatars, Turks and Roma) alike. Common to all three monasteries is the presence of allegedly miracle-working objects, artefacts and bodies: a stone cross at Dervent, the Virgin Mary icon at Nicula, and the tomb of the charismatic monk Arsenie Boca at Prislop, respectively. Based on ethnographic fieldwork conducted in the three monasteries during both important feasts and everyday monastic life, this article is a multidisciplinary exploration of the workings of inter-religious competition, sharing and interaction. It combines the methods typical of ethnographic research with observations on how the religious space is navigated and socialized through the support of cartography and archival satellite images. The article casts light on how the historical narratives and spatial strategies enacted by the Romanian Orthodox Church overlap in the attempt to reclaim legitimate ownership and exclusive primacy over three popular devotional sites with a composite ethnic and religious past.

So2 aerosol removal: The cause of global warming

Archived satellite images of atmospheric SO2 aerosols show that their decrease since 1980, due to global “Clean Air” efforts and Net Zero activities, is the cause of all of our modern warming. To avoid even more warming, and their associated environmental disasters, these activities need to be abandoned.

Impact of Dead Sea Halo-Karst Development on an Earthen Dike Rehabilitation Project

From the 1970s, the Dead Sea experienced severe halo-karstification and anthropogenic modifications. Progressively, but at an accelerating rate, subsidence, landslides, and sinkholes have increased in number and magnitude. The hazards’ triggering factors are the terminal lake level lowering at more than one meter per year and the dynamic equilibrium of the hydrogeological system. Over the Lisan peninsula, archived satellite images revealed the extent of the damaged areas. On 22 March 2000, the destruction of dike 19 represented a loss of 38 M USD. This is the most important event recorded since the beginning of the Dead Sea recession some 50 years ago. In 2018, a rehabilitation project of that dike started. This research analyses the viability of the reinstatement works. The advanced space borne radar interferometry technique is applied to map ground deformations before and during the project. This article reveals that the ongoing rehabilitation and reinstatement works of dike 19 are threatened by ongoing halo-karstification processes. Field observations and subsidence/uplift dynamics support this statement. The past experiences are taken into consideration to adapt industrial expansion strategies. However, the permeability of the salt pan floor could trigger a fast development of a karst system able to destroy the rehabilitated dike 19.

Study of changes in the boundaries of the «Rosha» micro-district of Chernivtsi

The study of the planning structure of settlements is quite relevant at the current stage. After all, this type of research makes it possible to ensure the most comfortable living conditions for the population and prospects for the development of the settlement. However, this type of research mainly concerns urban settlements in general or their administrative districts. As for the micro-districts of these same cities, several problematic moments hold scientists back. Chief among them is the limitation in primary statistical information that provides quantitative perception. Therefore, we conducted a study of the micro-district with the help of open Internet resources. With their help from the «OPENROUTSERVICE» internet resource, we calculated the estimated population of the micro-district. In this way, we calculated that about 10 % of the city’s entire population lives in the studied micro-district. We investigated changes in the built-up area of the micro-district in 1985, 2005, 2010, and 2020 using archival satellite images of the «Google Earth Pro» GIS service. In this application, we were able to calculate the total area of the neighborhood and separately the area of the built-up area. This information came in handy when calculating population density and building density. The results showed that the area of built-up areas increased almost three times in 35 years. So, according to the results of the research, the approximate population is 25 000 people with an average population density of 22.5 people/hectarе. The population density is slightly higher only in built-up areas and amounts to 32.5 people/hectarе. The built-up density of the territory of the micro-district is 69.2 %. Operating with actual indicators, we analyzed problematic and promising directions in the development of this part of the city.

Land Use/Land Cover Dynamics and Implications for Landscape Restoration in Cameroon’s Western Highlands

Land use – the way human beings employ the land and its resources is at the centre of scientific and policy interests in rapidly evolving landscapes of sub-Saharan Africa. An example par excellence of such landscapes is the Western Highland Region of Cameroon. This paper analyses the implications of land use changes in seven communities of the Western Highland Region of Cameroon. In doing so, it specifically: (i) examines the pattern of land use/land cover change between 1984 and 2021, and (ii) analyses their environmental implications. A mixed-methods approach involving the use of qualitative and quantitative data collection and analysis methods was employed. This specifically involved the survey of 300 households using semi-structured questionnaires, the conduct of nine (9) group discussions and twenty-two (22) key informant interviews. Secondary data were obtained through Municipal Council Reports. The data were analysed descriptively (using tables and charts) and spatially using maps. The study used archived satellite images to map land use dynamics over the study area from 1970’s to present. In this light, NASA’s Landsat satellite images from USGS earth explorer was acquired for the periods of 1979, 1984, 2000, 2013 and 2021 for diachronic analysis of land cover/use in the study area. The results revealed that land use/land cover changes were rapid, involving a significant reduction in grassland (72%), forests (48%) and bare areas (19%) between 1984 and 2021. This was followed by a correspondent increase (211%) in the built-up area, and in agricultural space (22%). Additionally, land use/land cover changes have led to a change in local climatic conditions, a decline in crop and livestock output, and rising food costs. The study recommends that international NGOs operating in this area should engage with communities on aspects of sustainable land management. Relevant government ministerial departments and municipal agents should emphasise the need to respect land use plans, to limit the uncoordinated colonisation of slopes for farming and settlement. Besides establishing the pattern of land use transformation in this landscape, this paper provides new insights on the environmental effects of land use/land cover dynamics in Cameroon’s Western Highlands. The results demonstrate novelty through its further identification of food security issues linked to land use/land cover dynamics.

Late Holocene initiation of a deep rock slope failure in an alpine valley revealed by 10Be surface exposure dating (Chamonix, France)

We studied a newly identified, multiple-kilometer-long rock slope failure in the Aiguilles Rouges massif (Chamonix valley, France). Owing to a high-resolution light detection and ranging (LiDAR) digital elevation model (DEM) and field work, we mapped morphostructures, including scarps, open fractures, and counterscarps. In some places, vertical offsets can reach tens of meters and crevasses can be meters wide. The evidence of gravitational activity (boulder displacements from analyses of archival satellite images) and the sharpness of the scarp outcrops together suggest very recent movements. These observations agree with ground displacement rates of a few millimeters per year estimated by interferometric synthetic aperture radar (InSAR) time series between 2014 and 2018.We sampled two vertical profiles along the top scarps to define the chronology of the slope failure using beryllium-10 (10Be) surface exposure dating. Glacially polished surfaces cut by these gravitational scarps were also sampled to determine glacial retreat timing as well as to constrain the pre-exposure 10Be inheritance. In total, 11 samples were studied.Our results highlight a significant time lag (approximately 15 ka) between the first evidence of nonglacial activity and the initiation of the slope failure that happened 1.3–2.5 ka ago, depending on the inheritance schemes. This suggests that the delayed opening of the crevasse is only one stage of a process that began when the valley was deepened and the glacial debuttressing is not the unique driving factor. This process of progressive failure of an excessively steep slope may continue, and the evolution of this slope failure may constitute a hazard for the upper part of the Chamonix valley.

Structure and variability of the main frontal zones in the White Sea during the warm season 2010

Analysis of archival satellite images of sea surface temperature from May to September 2010 allowed determining the features of the synoptic variability of these frontal zones. It is shown that the regions where extreme values of the sea temperature gradients and surface fronts occur occupy a significant sea area near the middle position of the frontal lines. In Dvinskiy Bay, this region occupies almost two thirds of the bay’s water area, and the displacement of the runoff front in its western flank reaches 70 km per month. All the fronts undergo the largest displacements in the first half of the warm season under the influence of synoptic processes and river runoff against the background of insufficient heating of the upper layer, but their high dynamic activity persists later, manifesting itself in the form of the formation of tongues and meanders up to several tens of kilometers. The greatest variability of the temperature field in the form of perturbations of the frontal section is demonstrated by the Gorlo frontal zone. This dynamics is an important element of water exchange in the strait.

Analogue-based colorization of remote sensing images using textural information

Satellite images are richer than ever before. For example, new Landsat-8 images with their 11 bands carry much more information than older generations of satellites. These differences in spectral representation imply a major difficulty for assessing long-term land surface changes. The easiest solution is to reduce the information of the most recent product, for example by only keeping a subset of the Landsat-8 bands that matches old imagery. To avoid such loss of information, we propose a new method based on multiband spatial pattern matching. We are focusing on increasing the spectral resolution of archive satellite images to the same level of spectral resolution and coverage as modern imagery. Our method uses analogous scenes taken from modern satellites, which have conceptually the same role as the training images used in multiple-point geostatistics simulation. The spectral characteristics of the training image are then transferred to a target archive image, where new synthetic spectral bands are generated. A spatial pattern matching procedure is used to control this transfer, resulting in preservation of spatial and spectral coherence in the results. We illustrate the methodology on Landsat 8 and Corona imagery. The proposed method was benchmarked against other state-of-the-art colorization techniques, and it shows globally better results.

How Can Remote Sensing Help in Detecting the Threats to Archaeological Sites in Upper Egypt?

The analysis of contemporary and archival satellite images and archaeological documentations presents the possibility of monitoring the state of archaeological sites in the Near East (for example, Palmyra in Syria). As it will be demonstrated in the case of Upper Egyptian sites, the rapid growth of agricultural lands and settlements can pose a great threat to sites localized on the border of fields and the desert. As a case study, the Qena district was chosen, a region of significance for the history of ancient Egypt. To trace the expansion of agriculture and the development of modern settlements, a synthesis of archival maps (from the last 200 years), and archival and contemporary satellite images was created. By applying map algebra to these documents, it was possible to determine areas which may be marked as “Archaeological Hazard Zones”. The analysis helped to trace the expansion of agricultural areas during the last 200 years and the influence of both—ancient Egyptians and the Nile—on the local landscape.

Possibilities of applying CORONA archive satellite images in forest cover change detection: Example of the Fruska Gora Mountain

This paper examines the possibilities, advantages and limitations of the use of high resolution archive satellite images in evaluation of forest and other land cover changes, based on research in the sample area of the Fruška Gora mountain (Serbia). Satellite images available from the declassified archives of CORONA program were used to assess the extent of forest cover in the past. By comparing the resulting datasets with newer images, changes in the forest coverage can be detected and reconstructed for a period of more than 40 years. Despite many limiting factors, the images provided valuable information about the state of the forest cover in the past. The methodology used can be utilized in other similar areas, where no other, more precise source is available about forest coverage, as a means of reasonably inexpensive and time efficient assessment of forest cover and other land use changes in the past five decades.

Quantitative Analysis of the Waterline Method for Topographical Mapping of Tidal Flats: A Case Study in the Dongsha Sandbank, China

Although the topography of tidal flats is important for understanding their evolution, the spatial and temporal sampling frequency of such data remains limited. The waterline method has the potential to retrieve past tidal flat topography by utilizing large archives of satellite images. This study performs a quantitative analysis of the relationship between the accuracy of tidal flat digital elevation models (DEMs) that are based on the waterline method and the factors that influence the DEMs. The three major conclusions of the study are as follows: (1) the coverage rate of the waterline points and the number of satellite images used to create the DEM are highly linearly correlated with the error of the resultant DEMs, and the former is more significant in indicating the accuracy of the resultant DEMs than the latter; (2) both the area and the slope of the tidal flats are linearly correlated with the error of the resultant DEMs; and (3) the availability analysis of the archived satellite images indicates that the waterline method can retrieve tidal flat terrains from the past forty years. The upper limit of the temporal resolution of the tidal flat DEM can be refined to within one year since 1993, to half a year since 2004 and to three months since 2009.

Combining remotely sensed surface energy fluxes and GIS analysis of groundwater parameters for irrigation system assessment

Despite being necessary for effective water management, the assessment of an irrigation system requires a large amount of input data for the estimation of related parameters and indicators, which are seldom measured in a regular and reliable manner. In this work, spatially distributed surface energy balance fluxes and geographical information systems analysis of multiple groundwater parameters were used to estimate water availability, supply, and demand, in order to calculate water-accounting indicators. This methodology was used to evaluate the performance of an irrigation system in the Pinios river basin (Greece) at two selected years of high and low water availability. Time series of archived satellite images and groundwater measurements have been used for past years to support comparative analyses, due to the limited availability of actual water measurements. The resulting maps from the proposed methodology show that the performance of the irrigation system varied across space and time due to differences in its characteristics and changes in its operation, driven by fluctuation of water availability and the response of stakeholders to water depletion. Irrigation districts with unsustainable water management were identified and, together with those with slow and/or limited groundwater recharge, were brought to the attention of water managers. The observed differences in the system operation between the wet and dry years were attributed not only to the hydrological conditions of each year, but also to the changing behaviour of farmers and the improvement actions of the water managers.

A rule-based semi-automatic method to map burned areas: exploring the USGS historical Landsat archives to reconstruct recent fire history

This study presents a new semi-automatic method to map burned areas by using multi-temporal Land Remote Sensing Satellite Program (Landsat) Thematic Mapper (TM) and Enhanced TM Plus (ETM+) images. The method consists of a set of rules that are valid especially when the post-fire satellite image has been captured shortly after the fire event. The overall accuracy of the method when applied to two case studies in Mt Parnitha and Samos Island in Greece were 95.69% and 93.98%, respectively. The commission and omission errors for Mt Parnitha were 6.92% and 10.24%, while those for Samos Island were 3.97% and 8.80%, respectively. Between the two types of error, it is preferred to minimize omission errors, since commission errors can be easily identified as part of product quality assessment and algorithm tuning procedures. The rule-based approach minimizes human interventions and makes it possible to run the mapping algorithm for a series of images that would otherwise need extensive time investment. In case of failure to capture burned areas correctly, it is possible either to make some adjustments by modifying the thresholding coefficients of the rules, or to discard some of the rules, since some editing is usually required to correct errors following the automated extraction procedures. When this method was applied to a series of US Geological Survey (USGS) Landsat TM and ETM+ archived satellite images covering the periods 1984–1991 and 1999–2009, a total of 1773 fires were identified and mapped from six different scenes that covered Attica and the Peloponnese in Greece. The majority of uncaptured burned areas corresponded to fires with size classes of 0–1 ha and 1–5 ha, where the loss in capturing fire scars is generally significant. This was expected since it is possible that small fires, identified and recorded by forest authorities, may not have been captured by satellite data due to limitations arising either from the spatial resolution of the sensor or imposed by the temporal series, which do not systematically cover the full period.

Quantifying tree mortality in a mixed species woodland using multitemporal high spatial resolution satellite imagery

Widespread tree mortality events have recently been observed in several biomes. To effectively quantify the severity and extent of these events, tools that allow for rapid assessment at the landscape scale are required. Past studies using high spatial resolution satellite imagery have primarily focused on detecting green, red, and gray tree canopies during and shortly after tree damage or mortality has occurred. However, detecting trees in various stages of death is not always possible due to limited availability of archived satellite imagery. Here we assess the capability of high spatial resolution satellite imagery for tree mortality detection in a southwestern U.S. mixed species woodland using archived satellite images acquired prior to mortality and well after dead trees had dropped their leaves. We developed a multistep classification approach that uses: supervised masking of non-tree image elements; bi-temporal (pre- and post-mortality) differencing of normalized difference vegetation index (NDVI) and red:green ratio (RGI); and unsupervised multivariate clustering of pixels into live and dead tree classes using a Gaussian mixture model. Classification accuracies were improved in a final step by tuning the rules of pixel classification using the posterior probabilities of class membership obtained from the Gaussian mixture model. Classifications were produced for two images acquired post-mortality with overall accuracies of 97.9% and 98.5%, respectively. Classified images were combined with land cover data to characterize the spatiotemporal characteristics of tree mortality across areas with differences in tree species composition. We found that 38% of tree crown area was lost during the drought period between 2002 and 2006. The majority of tree mortality during this period was concentrated in piñon-juniper (Pinus edulis-Juniperus monosperma) woodlands. An additional 20% of the tree canopy died or was removed between 2006 and 2011, primarily in areas experiencing wildfire and management activity. -Our results demonstrate that unsupervised clustering of bi-temporal NDVI and RGI differences can be used to detect tree mortality resulting from numerous causes and in several forest cover types.

Disappearing Arctic Lakes

Historical archived satellite images were compared with contemporary satellite data to track ongoing changes in more than 10,000 large lakes in rapidly warming Siberia. A widespread decline in lake abundance and area has occurred since 1973, despite slight precipitation increases to the region. The spatial pattern of lake disappearance suggests (i) that thaw and "breaching" of permafrost is driving the observed losses, by enabling rapid lake draining into the subsurface; and (ii) a conceptual model in which high-latitude warming of permafrost triggers an initial but transitory phase of lake and wetland expansion, followed by their widespread disappearance.

Influence of glacial retreat on natural hazards of the Palcacocha Lake area, Peru

In this article we describe natural hazards associated with outburst floods of Palcacocha Lake and landslide events on the slopes of its moraine dam, in Cojup Valley, Cordillera Blanca (Peru). These events occurred in the last 70 years and some of them resulted in disasters, which strongly affected the city of Huaras. Field investigations and reference expression hydrodynamic tests as well as archive satellite images and aerial pictures were used to describe the evolution of hazards connected with Palcacocha Lake. Expression hydrodynamic tests proved a high permeability of sandy gravels glacial sediments, which form the present-day lake dam. Seepage through the natural dam forming small ponds below the overflow spillways occurs. A retreat of the glacial tongue causing an increase of the lake volume and unloading of the slope toe areas are the most important recent processes that influence the potential hazards affecting the Cojup valley. The research has proved that the climate warming and ongoing deglaciation play a very significant role in the change of natural hazards conditions in high mountains.

Using Remote Sensing to Reassess the Mass Mortality of Diadema antillarum 1983–1984

Abstract: The 1983–1984 mass mortality of the sea urchin Diadema antillarum remains one of the most severe die‐offs ever recorded in the Caribbean. Before 1983, the herbivore D. antillarum was pervasive on coral reefs in the region. Nine months after first detection of the mass mortality, 95% of the urchins had perished, and algal cover of coral increased between 100% and 250%. A water‐borne pathogen was hypothesized as the causative agent, but it was never isolated. To date, surface current patterns have been used exclusively to explain both the cause and the distribution patterns of the mortality event. Using archived satellite images, we re‐examined the water‐borne pathogen hypothesis and investigated whether other mechanisms could also account for the dissemination pattern in some areas. In addition, archived satellite images were utilized to detect changes in coral reef reflectance. For infections in the Gulf of Mexico and Bermuda, satellite images confirm that surface currents are likely responsible for the distribution of the pathogen. For infections in the eastern Caribbean (Curacao, U.S. Virgin Islands, Barbados), however, another mechanism, possibly ballast water exchange, must be considered because the surface current and infection patterns do not coincide. Changes in coral reflectance were detectable from Landsat thermatic mapping data before and after the mass mortality and correspond to the change in algal cover. Results from our study demonstrate the potential of satellite images for use in determining connectivity between regions of the Caribbean and in detecting changes in coral reef cover.

The plume of the Yukon River in relation to the oceanography of the Bering Sea

Physical and biological oceanography of the northern Bering Sea including the plume of the Yukon River were studied using satellite data in conjunction with shipboard measurements. The satellite data recorded by the NOAA Very High Resolution Radiometer (VHRR) and Advanced Very High Resolution Radiometer (AVHRR), and the Landsat Multispectral Scanner (MSS) and Thematic Mapper (TM) sensors were used to detect sea surface temperatures and suspended sediments. Shipboard measurements of temperature, salinity, and chlorophyll were acquired by the Inner Shelf Transfer and Recycling (ISHTAR) project and were compared to digitally enhanced and archived satellite images. Sea surface temperatures derived from satellite data were generally higher than field measurements. This difference was the likely result of microscale stratification of the water column, although other factors could have been involved also. Satellite data confirmed the known distribution of water masses in the region (Coachman et al., 1975). Upwelled water of oceanic origin (Anadyr Water) was visible as a cold surface plume running from Anadyr Strait north through western Bering Strait. In the east, warm Alaskan Coastal Water was prominent along the Alaskan coast including Norton Sound and the southeastern Chukchi Sea. Areal patterns of temperature, salinity, and phytoplankton distribution, determined from field measurements, agreed reasonably well with patterns of water mass distribution obtained from satellite images. Archived satellite images (1974–1978) were used to investigate the variability of the distribution of sea surface temperature and of the turbid plume of the Yukon River. Alaskan Coastal Water (ACW) first warms near the coast in June and the process extends seaward as summer progresses. Turbid water associated with discharge of the Yukon River progresses in the same fashion, extending northward across the entrance to Norton Sound. Maximum extent of the plume occurs in October. Anadyr Water flows north through Anadyr Strait past St. Lawrence Island; its extent is variable depending on mesoscale pressure and local wind fields.