Historical Satellite Imagery Research Articles

Ice flow velocity of the Nioghalvfjerdsfjorden Glacier and Zachariæ Isstrøm, Northeast Greenland, in the 1960s from Historical Satellite Imagery

Ice flow velocity of the Nioghalvfjerdsfjorden Glacier and Zachariæ Isstrøm, Northeast Greenland, in the 1960s from Historical Satellite Imagery

Long-term assessment of historical disturbances in the dry land ecosystems of Mutis Timau Nature Reserve, East Nusa Tenggara, Indonesia

Long-term assessment using historical satellite imagery is critical for gaining meta-information and identifying trends in land cover change. Informed policymaking about this assessment ensures forest sustainability and mitigates climate change to consider the identified trends in land cover changes and historical disturbances. Therefore, this study aimed to describe the trend of land cover change and historical disturbances in Mutis Timau Nature Reserve (CA Mutis Timau), Indonesia using the LandTrendr platform. The land cover classification is based on SNI 7645-1:2014, with a 1:50,000 scale. The data was processed using Google Earth Engine’s LandTrendr platform, which covered the vegetation index, specifically the normalized burn ratio (NBR). The results showed that the trend of land cover change in CA Mutis Timau remained stable from 1986 to 2023. These disturbance locations have low slopes and are located near neighborhoods. In specifics, the Eucalyptus forest land cover experienced the largest land cover change between 1986 and 2023, losing 945.68 ha of vegetation, or 8% of the total area of CA Mutis Timau. Over a duration of 38 years, from 1986 to 2023, the Eucalyptus forest had a cover change that turned into marble stone, barren land, grassland, and shrubs. Forest management policies, such as establishing a nature reserve area on Mount Mutis areas, had an impact on the long-term sustainability of vegetation land cover.

Probabilistic Method to Fuse Artificial Intelligence-Generated Underground Utility Mapping.

Utility as-built plans, which typically provide information about underground utilities' position and spatial locations, are known to comprise inaccuracies. Over the years, the reliance on utility investigations using an array of sensing equipment has increased in an attempt to resolve utility as-built inaccuracies and mitigate the high rate of accidental underground utility strikes during excavation activities. Adapting data fusion into utility engineering and investigation practices has been shown to be effective in generating information with improved accuracy. However, the complexities in data interpretation and associated prohibitive costs, especially for large-scale projects, are limiting factors. This paper addresses the problem of data interpretation, costs, and large-scale utility mapping with a novel framework that generates probabilistic inferences by fusing data from an automatically generated initial map with as-built data. The probabilistic inferences expose regions of high uncertainty, highlighting them as prime targets for further investigations. The proposed model is a collection of three main processes. First, the automatic initial map creation is a novel contribution supporting rapid utility mapping by subjecting identified utility appurtenances to utility inference rules. The second and third processes encompass the fusion of the created initial utility map with available knowledge from utility as-builts or historical satellite imagery data and then evaluating the uncertainties using confidence value estimators. The proposed framework transcends the point estimation of buried utility locations in previous works by producing a final probabilistic utility map, revealing a confidence level attributed to each segment linking aboveground features. In this approach, the utility infrastructure is rapidly mapped at a low cost, limiting the extent of more detailed utility investigations to low-confidence regions. In resisting obsolescence, another unique advantage of this framework is the dynamic nature of the mapping to automatically update information upon the arrival of new knowledge. This ultimately minimizes the problem of utility as-built accuracies dwindling over time.

Understanding the transition of community land use from shifting cultivation to cash cropping in southern Tanintharyi, Myanmar

Abstract Many tropical landscapes have experienced the loss of traditional cultivation practices as they have transitioned to other land use systems. The Tanintharyi Region of southern Myanmar is a landscape experiencing a rapid land use regime shift from traditional subsistence farming to permanent cash crop agriculture. Despite previous research in this region on the expansion of large‐scale agribusiness, such as oil palm and rubber plantations, little is known about how the small‐scale shifting cultivation system practiced by the local Karen ethnic people in Tanintharyi has changed over recent decades or the underlying reasons for this transition. Our study explores this transition process and its drivers from a social and land system change perspective in four villages of Bokpyin Township in Tanintharyi. We investigated the drivers of land cover and land use change by collecting information through focus groups and individual interviews with community members who previously practised shifting cultivation. We also quantified the overall change in land cover and land use through remote sensing analysis of Landsat 8 (2020) and declassified KH‐9 satellite imagery (1976). Prior to a period of civil war in the 1980s, cultivators used a traditional ‘slash‐and‐burn’ agricultural system for subsistence use. The present land use system is dominated by permanent betel nut cultivation, which represents the primary income source for farming households. The reported drivers of the transition to cash crop farming are greater income potential and livelihood security, risk of losing fallow land due to the needs for new cultivation areas for in‐migration and new centralized land use policies and administration after the national ceasefire agreement in 2012. The documented change in land use systems has been paired with a concurrent net loss of forest that, given the conflicted governance within the landscape, seems likely to continue without additional land use planning efforts. Our study contributes to an increased understanding of changes in shifting cultivation systems that are being documented globally. Furthermore, our example of combining qualitative interviews with analysis of historical satellite imagery to detect and explain land use regime shifts can serve as a model for future work in different landscapes. Read the free Plain Language Summary for this article on the Journal blog.

Characterization of landuse and landcover dynamics and their impact on runoff generation patterns in dam catchments of Northern Ghana

Landuse alteration is a critical factor that exerts influence over hydrological mechanisms and the oversight of water resources across the globe. Northern Ghana is characterized by erratic rainfall, leading to the intense construction of small dams and dugouts. This study investigated historical landuse/cover (LULC) changes and physical factors associated with surface runoff generation within eight (8) sub-catchments namely; Guno, Gbahali, Sambu, Duago, Denugo, Kwisini, Sandu, and Nyeko, with areas of 29.5, 110, 38.5, 106.04, 67.81, 2.59, 10.56 and 120.65 km2, respectively, located in four (4) regions of northern Ghana. For LULC change detection, historical satellite imagery and geospatial data were used with the aid of remote sensing and applying supervised maximum likelihood classification to Landsat images of 1995, 2005, 2015, and 2023. Runoff factors and depths were identified based on LULC classes, hydrologic soil groups, and precipitation conditions prevailing in the areas, based on the curve number (CN) method. With regards to LULC, the results from the overall analysis gave an insight into the rampant conversion, where grassland/mix vegetation witnessed significant declines, with decreases ranging from 150 to 395.25% in different catchments. Agricultural and arable lands emerged as the dominant landuse category, indicating a remarkable expansion of 11.61–51.17 km2, from 1995 to 2023 respectively, followed by built-up areas. While grassland decreased in all catchments over the same period, in some places, open tree (savannah woodland) increased, which confirmed the implementation of the afforestation policy. The CN values offered essential insights into the hydrological characteristics of each catchment. In addition to the impact of LULC and watershed characteristics on runoff, the observed variations in runoff patterns can be attributed to interannual variability in total annual precipitation which is critical driver of runoff. The findings hold significant importance for developing effective strategies and integrated watershed management policies to contribute to better water resource management and inform sustainable landuse planning in the face of changing environmental conditions.

Digital encounters with microbial ecologies in a polluted urban river

Despite their ubiquity and ecological heterogeneity, non-pathogenic microorganisms are often lacking in accounts of more-than-human and other-than-human urbanisms. This article focuses on the use of digital technologies as practice for sensing and encountering unglamorous microbial ecologies emerging in a polluted urban river in East London. The River Lea has a dense industrial history, but today it is a site of post-industrial disuse, uneven development and burgeoning urban ecologies. In an easily bypassed segment of this urban river, microbial ecosystems bloom in and out of existence, reflecting a confluence of urban political ecological, hydrological and microbiological dynamics. These ecosystems are generally overlooked in accounts of urban ecological value, and are often framed as uncharismatic, accidental or even invasive. The aim of this work is to provide an alternative rendering of these slimy micro-ecologies. To this end, two digital approaches are explored: deployment of in situ micro-videography and attention to historical satellite imagery of the urban ecosystem. Microscopic approaches configure embodied, sensory, aesthetic and speculative encounters with microbial ecologies in urban space. In their temporal configuration, historical satellite approaches glimpse the machinations of urban political ecological dynamics as they contribute to the emergence of, and intersect with, recombinant urban ecosystems. These methods provide tools for cultural geographers studying how urban organisation affects ecological diversity, and for expanding geographic investigation into the more-than-human cultures of overlooked, unglamorous and uncharismatic urban lifeforms.

Interactive Digital Platforms, Human Rights Fact Production, and the International Criminal Court

Abstract The International Criminal Court (ICC) initiated criminal proceedings against Ahmad Al Faqi Mahdi in 2016 for the war crime of directing the destruction of religious monuments in Timbuktu, Mali, in the context of a non-international conflict. The monuments included nine mausoleums of Sufi saints that Islamist groups regarded as idolatrous, one mosque, and approximately four thousand ancient manuscripts. The case, which successfully ended in a guilty plea, marks the first time that the ICC charged an individual with a ‘cultural heritage’ crime. The prosecution’s argument during the hearing relied heavily on an interactive digital platform that facilitated the organization, analysis, and presentation of the evidence to the court. SITU, an applied research organization, created the platform in collaboration with the ICC’s Office of the Prosecutor. It combined geospatial information, historic satellite imagery, photographs, open-source videos, and other types of site documentation to help the ICC judges visualize what was no longer physically there. The result was a digital reconstruction featuring structures and their contents lost to explosives, pickaxes, and hammers. The theoretical, methodological, and ethical issues that arose out of the collaboration, the focus of this article, highlights the multiple ways in which such platforms fashion ‘facts’ rather than objectively present them. A close analysis of the design decisions made, visualization techniques employed, and presentation strategies used to support the case against the defendant highlights both the possibilities and limits of such platforms as part of future international criminal proceedings.

Assessment of the Capability of Landsat and BiodivMapR to Track the Change of Alpha Diversity in Dryland Disturbed by Mining

Remotely sensed spectral diversity is a promising method for investigating biodiversity. However, studies designed to assess the effectiveness of tracking changes in diversity using historical satellite imagery are lacking. This study employs open-access multispectral Landsat imagery and the BiodivMapR package to estimate the multi-temporal alpha diversity in drylands affected by mining. Multi-temporal parameters of alpha diversity were identified, such as vegetation indices, buffer zone size, and the number of clusters. Variations in alpha diversity were compared for various plant communities over time. The results showed that this method could effectively assess the alpha diversity of vegetation (R2, 0.68). The optimal parameters used to maximize the accuracy of alpha diversity were NDVI threshold, 0.01; size of buffer zones, 120 m × 120 m; number of clusters, 100. The root mean square error of the alpha diversity of herbs was lowest (0.26), while those of shrub and tree communities were higher (0.34–0.41). During the period 1990–2020, the study area showed an overall trend of increasing diversity, with surface mining causing a significant decrease in diversity when compared with underground mining. This illustrates that the quick development of remote sensing and image processing techniques offers new opportunities for monitoring diversity in both single and multiple time phases. Researchers should consider the plant community types involved and select locally suitable parameters. In the future, the generation of long-time series and finer resolution maps of diversity should be studied further in the aspects of spatial, functional, taxonomic, and phylogenetic diversity.

Supplying a medieval metropolis: water management and agriculture in the hinterland of early Islamic Basra

Following its foundation in the 630s CE, medieval Basra rapidly expanded to became one of the most populous cities of southern Iraq and the wider Gulf region. At its foundation, the city’s surrounding environment appears to have been poorly suited to sustaining a large urban population. This paper examines the different ways in which the early Islamic population of Basra transformed the immediate environs of the city to improve the urban water supply and the agricultural potential of the city’s hinterland. In particular, this included the construction of substantial canals connecting Basra with sources of water such as the marshes to the north of the city and the Shaṭṭ al-cArab—the river which forms at the confluence of the Tigris and Euphrates and flows past Basra to the Gulf. The tidal influence of the Gulf causes the water level of the Shaṭṭ al-cArab to rise and fall daily and, by exploiting this characteristic, the medieval population of Basra could irrigate large swathes of land surrounding the city. Analysis of historic satellite imagery reveals possible evidence for the infrastructure that made this possible—including the remains of field systems bounded by, and interspersed with, canals as well as large raised linear ridge features which occur in tandem with relict canal systems. This paper critically assesses the evidence for the dating of these features, potential scenarios for how they functioned and their relationship to the medieval city of Basra.

A method for considering the evolution of the visible landscape

The visible landscape represents an important consideration within landscape management activities, forming an inhabitants’ perception of their overall surroundings and providing them with a sense of landscape connection, sustainability and identity. The historical satellite imagery archive can provide key knowledge of the overall change in land use and land cover (LULC), which can inform a range of important management decisions. However, the evolution of the visible landscape at a terrestrial level using this information source has rarely been investigated. In this study, the Landsat archive is leveraged to develop a method that depicts changes within the visible landscape. Our method utilises other freely available data sources to determine the visibility of the landscape, and LULC composition, visible from road networks when the imagery was captured. This method was used to describe change in the visible landscape of a rural area in Ñuble, Chile, in the period from 1986 to 2018. Whilst native forests on the slopes of the mountains within the study area provide a natural backdrop, because of the flat topography of most of the area, the foreground dominates the overall landscape view. This has resulted in a visible transition from a landscape visibly dominated by agricultural use in 1986 to one of equal agriculture and plantation forestry in 2018. It is hoped that the method outlined within this study can be applied easily to other regions or at larger scales to provide insight for land managers regarding the visibility of LULC.

The form evolution and environmental adaptaion of villages along a river: A case study of the dong villages in the Gaojin‐Bazhai Valley

AbstractWith the overall improvement of China's rural settlements, the spatial form of villages has undergone dramatic changes. The Dong villages in the mountainous regions of southwest China are closely tied to rivers and have always maintained remarkable water adaptability even under the intense development and construction disturbances of the past 30 years, providing a direct model for the sustainable development of modern communities. This paper takes the Gaojin‐Bazhai valley, Guizhou Province, and the eight Dong villages in it as a case study, using multisource data such as high‐resolution historical satellite imagery, participatory spatial mapping, interviews with key figures, and ethnography, and integrates the research methods of spatial analysis and anthropological field surveys to trace village spatial development at three levels: valley, village, and building groups. The study reveals the interaction between the Dong villages and the water environment over a long time period, and reveals a coupled artificial–natural interaction mechanism with water adaptation as the core, which is specifically interpreted as restriction, induced, adjustment, and synergy effects. With the aim of promoting a more effective succession of this mechanism, we also propose policy recommendations for the development of the water environment in the river basin as a response to the challenges arising from the ecological and ethnological conflict brought by modernization and tourism.

Satellite-derived bathymetry using machine learning and optimal Sentinel-2 imagery in South-West Florida coastal waters

ABSTRACT This study examines the use of the Multi-Spectral Instrument (MSI) in Sentinel-2 satellite in combination with regression-based random forest models to estimate bathymetry along the extended southwestern Florida nearshore region. In this study, we focused on the development of a framework leading to a generalized Satellite-Derived Bathymetry (SDB) model applicable to an extensive and diversified coastal region (>200 km of coastline) utilizing multi-date images. The model calibration and validation were done using airborne lidar bathymetry (ALB). As ALB surveys are very expensive to conduct, the proposed model was trained with a limited and practically feasible ALB data sample to expand the model’s practicality. Out of the three different sub-models introduced using varying combinations of historical satellite imagery, the combined-band model with the largest feature pool yielded the highest accuracy. The results showed root mean square error (RMSE) values of 8% and lower for the 0–13.5 m depth range (limit of the lidar surveys used) for all areas of interest, indicating the model efficiency and adaptability to varying coastal characteristics. The influence of training sample locations on model performance was evaluated using three distinct model configurations. The difference between these configurations was less than 5 cm, which highlights the robustness of the proposed SDB model. The quality of the satellite imagery is a significant factor that influences the accuracy of the bathymetry estimation. A preliminary methodology incorporating spectral data embedded in Sentinel-2 imagery to effectively select the most optimal satellite imagery was also proposed in this study.

Mangroves Cover Change Trajectories 1984-2020: The Gradual Decrease of Mangroves in Colombia

Awareness of the significant benefits of mangroves to human lives and their role in regulating environmental processes has increased during the recent decades. Yet there remains significant uncertainty about the mangrove change trajectories and the drivers of change at national scales. In Colombia, the absence of historical satellite imagery and persistent cloud cover have impeded the accurate mapping of mangrove extent and change over time. We create a temporally consistent Landsat-derived dataset using the LandTrendr algorithm to track the historical land cover and mangrove conversion from 1984-2020 across Colombia. Over this period, mangrove extent decreased by ~48.000ha (14% of total mangrove area). We find a gradual reduction of mangrove extent along the Pacific coast since 2004, whereas, in the Caribbean, mangrove cover declined around during 1984-1988 and also after 2012. Our time-series analysis matches with drivers of mangrove change at three local sites. For instance, hydroclimatic events, dredging activities, and high sediment loads transported by the rivers have collectively improved mangrove recovery in some sites. In contrast, human activities pressure linked to agricultural expansion and road construction have degraded mangroves. The transition from dense mangrove to other vegetation types is the most significant conversion affecting mangrove cover in Colombia, impacting an area of 38,469 ± 2,829 ha. We anticipate increased mangrove loss, especially along the Pacific coast, resulting from intensified human activity. Prioritization of conservation areas is needed to support local institutions, maintain currently protected areas, and develop strategies (e.g. payment for ecosystem services) to preserve one of the most pristine mangrove regions in the Western Hemisphere.

Aroturuki te takutai moana mai i te rangi: Using satellite and UAV imagery to map the dynamics of the coast at sites with anthropogenic debris in Southland, New Zealand

The coast is a naturally active margin that forms an important barrier system subjected to the forces of both the terrestrial and marine environment. Coastal erosion has become a problem where infrastructure and debris along the shore are being consumed by the ocean. The overall aim of the study is to evaluate and generate effective monitoring and management of the changing coast at sites with anthropogenic debris. This study investigates four sites along the southern coast of the South Island, New Zealand. The sites investigated are Monkey Island, Colac Bay, Fortrose, and Porpoise Bay. Historic satellite imagery is used to investigate coastal dynamics by extracting the rate and magnitude of change occurring from past shorelines. 3D imagery was collected using a drone to collect volumetric change. Each site has shown a range of dynamics along the coast that can be defined into four different patterns. These patterns are stable, unstable, eroding and accreting. Sites without human intervention show constant signs of erosion. Human intervention from reinforcement prevents the coastline from retreating. This is seen at Colac Bay and Fortrose. Porpoise Bay has an unstable coastline and new houses are being built along the beach where the soil underneath them is just sand. The overall results will aid in predicting future shorelines and monitoring and managing coastal change.

Overestimation and adjustment of Antarctic ice flow velocity fields reconstructed from historical satellite imagery

Abstract. Antarctic ice velocity maps describe the ice flow dynamics of the ice sheet and are one of the primary components used to estimate the Antarctic mass balance and contribution to global sea level changes. In comparison to velocity maps derived from recent satellite images of monthly to weekly time spans, historical maps, from before the 1990s, generally cover longer time spans, e.g., over 10 years, due to the scarce spatial and temporal coverage of earlier satellite image data. We found velocity overestimations (OEs) in such long-span maps that can be mainly attributed to velocity gradients and time span of the images used. In general, they are less significant in slow-flowing grounded regions with low spatial accelerations. Instead, they take effect in places of high ice dynamics, for example, near grounding lines and often in ice shelf fronts. Velocities in these areas are important for estimating ice sheet mass balance and analyzing ice shelf instability. We propose an innovative Lagrangian velocity-based method for OE correction without the use of field observations or additional image data. The method is validated by using a set of ground truth velocity maps for the Totten Glacier and Pine Island Glacier which are produced from high-quality Landsat 8 images from 2013 to 2020. Subsequently, the validated method is applied to a historical velocity map of the David Glacier region from images from 1972–1989 acquired during Landsat 1, 4, and 5 satellite missions. It is demonstrated that velocity overestimations of up to 39 m a−1 for David Glacier and 195 m a−1 for Pine Island Glacier can be effectively corrected. Furthermore, temporal acceleration information, e.g., on basal melting and calving activities, is preserved in the corrected velocity maps and can be used for long-term ice flow dynamics analysis. Our experiment results in the Pine Island Glacier (PIG) show that OEs of a 15-year span can reach up to 1300 m a−1 along the grounding line and cause an overestimated grounding line (GL) flux of 11.5 Gt a−1 if not corrected. The magnitudes of the OEs contained in both velocity and mass balance estimates are significant. When used alongside recent velocity maps of 1990s–2010s, they may lead to underestimated long-term changes for assessment and forecast modeling of the global climate change impact on the Antarctic ice sheet. Therefore, the OEs in the long-span historical maps must be seriously examined and corrected. We recommend that overestimations of more than the velocity mapping uncertainty (1σ) be corrected. This velocity overestimation correction method can be applied to the production of regional and ice-sheet-wide historical velocity maps from long-term satellite images.

Development of Altyn Köprü (Pirdi) in the light of new Archaeological and Historical Research

Based on a thorough archaeological and historical research, this paper traces the development of Altyn Köprü (Pirdi), the city situated on the islet in the river of Little Zab, from its presumed Assyrian origin until the 19th century. The study draws from a rich data set obtained from in-depth analysis of historical satellite imagery and the archaeological field survey conduced by the Czech Archaeological Mission in Iraqi Kurdistan (project Medieval Urban Landscape in Northeastern Mesopotamia – Mulinem) between 2013 and 2014, in coperation with archaeologists from Salahaddin University Arbil and Inspectorate of Antiquities Kirkuk. Historical travel literature and photographs, as well as Ottoman drawings and plan documentation enabled us to trace in detail the origin and development of the townʼs landmarks – the bridges that once connected the islet with the south and north banks of the river. The last phase of the Ottoman bridges (demolished in 1918) can be dated, according to our analysis, sometime before 1736 and their remnants are still visible in the ground, together with traces of older bridges of unknown date. Furthermore, we argue that the town underwent a complete transformation of urban structure, street network, and architectural appearance between the 16th and 20th century.

Beyond the myths about Indonesia’s deforestation: linking oil palm cultivation to forest degradation and sustainable development goals

Oil palm cultivation is under scrutiny by various stakeholders, arguing that it is the main cause for Indonesia’s deforestation. This paper highlights the decades of forest degradation before the first land clearing for oil palm within the context of Indonesia’s development policies. Using ‘direct photointerpretation’ of ‘Historical Imagery’, it assesses the forest degradation and deforestation caused by oil palm cultivation in Indonesia, particularly in light of the UN Sustainable Development Goals (SDGs). Forest degradation has direct trade-offs with most of the SDGs, with the most affected SDGs being Responsible Consumption and Production (SDG12) and Life on Land (SDG15). Historical satellite imagery indicates that the first land clearing for the 176 Kha of oil palm estates sampled palm occurred around 1994. In contrast, only half of this area contained (natural) forests in 1984- a decade before the first land clearing. None of the remaining forests were (near) intact natural forests; all were (heavily) degraded and their biodiversity was strongly compromised. This indicates that oil palm cultivation is not linked to the degradation of Indonesia’s natural forests. Regarding SDG12, we found significant positive impacts from both the direct and indirect land-use changes by oil palm. For SDG15, we observed major positive impacts from the direct land-use changes and minor positive impacts from the indirect land-use changes. Hence, we conclude that oil palm cultivation in the sampled estates has positive impacts on Indonesia’s SDGs and Indonesia’s development policies align with its SDGs.

The geologic record of Hurricane Irma in a Southwest Florida back-barrier lagoon

On 10 September 2017, Category 3 Hurricane Irma made landfall along the Southwest Florida coastline between Cape Sable and Cape Romano. Geologic evidence of this storm is preserved in a back-barrier lagoon behind the Big Hickory Barrier Island, which is located ~64 km north of the landfall point and is positioned 43–65 m east of the Gulf of Mexico. Modern dune height is ~0.83–0.88 m, which was exceeded by the storm surge (recorded height 0.9–1.5 m) allowing for sediment deposition in the Big Hickory Island Lagoon. Geologic evidence is likely found at this location due to proximity to the Gulf of Mexico and the shallow barrier itself. Three cores were analyzed for moisture, inorganic content, grain size, and foraminiferal assemblages. The presence of a hurricane signature (tempestite) is evident in the uppermost horizon of all the cores and includes a fining upward trend of medium sand to clay against a background of organics and fine-grained sediments. Tempestite layers were thicker behind narrower sections of the beach, indicating preferential back-barrier deposition behind narrow barrier sections. Several different foraminiferal species within the tempestite sediments corroborate a marine sediment origin. In addition, historic satellite imagery shows that the Big Hickory Barrier Island is very susceptible to geomorphological change through time, especially due to storm impacts. This research demonstrates the utility of back-barrier sediment cores in understanding hurricane history and barrier island vulnerability.

Landslide Assessment Using Normalized Difference Vegetation Index (NDVI) Technique in Sentong, Lojing, Kelantan, Malaysia

The study area is a part of Lojing and it is lies between latitude 4° 45’ 30” N – 4° 49’ 0” N and longitude 101° 45’ 30” E – 101° 48’ 30”E. This study was focused on assessing of vulnerable locations of landslide based on satellite imageries of different years (2006, 2014 and 2015) which selected for visual interpretation and vegetation indices (VIs). As a result, there were 18 locations of landslide determined which landslide had occurred. With the aid of historical satellite imagery and the obtained quantitative data, the areas for landslide occurred were detected. Besides, the approach of remote sensing technique in landslide assessment was defined in terms of the early precautions for landslides, thus, the lost from landsides can be reduced. Furthermore, the condition of existing landslide areas was monitored by referring to the satellite imagery. This study can helpful to develop the inhabitant of the area and as well as to improve the poverty eradication.

Clinging to survival: Critically Endangered Chapman's pygmy chameleon Rhampholeon chapmanorum persists in shrinking forest patches

AbstractThe Critically Endangered Chapman's pygmy chameleon Rhampholeon chapmanorum is endemic to the low elevation rainforest of the Malawi Hills in southern Malawi. Much of this forest has been converted to agriculture and it was uncertain whether chameleon populations have persisted. We used current and historical satellite imagery to identify remaining forest patches and assess deforestation. We then surveyed forest patches for the presence of this chameleon, and assessed its genetic diversity and structure. We estimated that 80% of the forest has been destroyed since 1984, although we found extant populations of the chameleon in each of the patches surveyed. Differentiation of genetic structure was strong between populations, suggesting that gene flow has been impaired. Genetic diversity was not low, but this could be the result of a temporal lag as well as lack of sensitivity in the mitochondrial marker used. Overall, the impact of forest loss is assumed to have led to a large demographic decline, with forest fragmentation preventing gene flow.