scholarly journals A Probabilistic Assessment of Soil Erosion Susceptibility in a Head Catchment of the Jemma Basin, Ethiopian Highlands

Geosciences ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 248 ◽  
Author(s):  
Mariaelena Cama ◽  
Calogero Schillaci ◽  
Jan Kropáček ◽  
Volker Hochschild ◽  
Alberto Bosino ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Soil Erosion ◽  
Remote Sensing Data ◽  
Gully Erosion ◽  
Entropy Model ◽  
Global Issues ◽  
Susceptibility Maps ◽  
Digital Elevation ◽  
Elevation Model ◽  
Color Composite

Soil erosion represents one of the most important global issues with serious effects on agriculture and water quality, especially in developing countries, such as Ethiopia, where rapid population growth and climatic changes affect widely mountainous areas. The Meskay catchment is a head catchment of the Jemma Basin draining into the Blue Nile (Central Ethiopia) and is characterized by high relief energy. Thus, it is exposed to high degradation dynamics, especially in the lower parts of the catchment. In this study, we aim at the geomorphological assessment of soil erosion susceptibilities. First, a geomorphological map was generated based on remote sensing observations. In particular, we mapped three categories of landforms related to (i) sheet erosion, (ii) gully erosion, and (iii) badlands using a high-resolution digital elevation model (DEM). The map was validated by a detailed field survey. Subsequently, we used the three categories as dependent variables in a probabilistic modelling approach to derive the spatial distribution of the specific process susceptibilities. In this study we applied the maximum entropy model (MaxEnt). The independent variables were derived from a set of spatial attributes describing the lithology, terrain, and land cover based on remote sensing data and DEMs. As a result, we produced three separate susceptibility maps for sheet and gully erosion as well as badlands. The resulting susceptibility maps showed good to excellent prediction performance. Moreover, to explore the mutual overlap of the three susceptibility maps, we generated a combined map as a color composite where each color represents one component of water erosion. The latter map yields useful information for land-use managers and planning purposes.

scholarly journals CREATION OF GIS-RESOURCES FOR PHYSIOGRAPHIC ZONING OF THE TRANSBOUNDARY RUSSIAN-MONGOLIAN TERRITORY

2021 ◽  
Vol 26 (2) ◽  
pp. 91-102
Author(s):  
Andrew N. Beshentsev ◽  
◽  
Alexander A. Ayurzhanaev ◽  
Bator V. Sodnomov ◽  
◽  
...  
Keyword(s):  
Remote Sensing ◽  
Remote Sensing Data ◽  
Landsat Images ◽  
Statistical Research ◽  
Active Biomass ◽  
Sensing Data ◽  
Digital Elevation ◽  
Geographical Regions ◽  
Elevation Model ◽  
Geographical Characteristics

The article is aimed at the development of methodological foundations for the creation of geoin-formation resources of transboundary territories based on cartographic materials and remote sensing data, as well as physical and geographical zoning of the transboundary Russian-Mongolian territory. The methodological basis of the study is cartographic and statistical research methods, geoinformation technology, as well as processing and analysis of remote sensing data. As a result, the study deter-mines the features of geoinformation resources, presents their characteristics, develops a classification and substantiates their integrating value in making interstate territorial decisions. The article gives the physical and geographical characteristics of the territory, determines the scale of mapping, establishes the basic units of geoinformation mapping and modeling, creates the coverage of the basin division, and proposes a scheme for creating basic geoinformation resources for the physical and geographical zoning of the territory. Based on the analysis of the digital elevation model, the territory was zoned according to the morphometric parameters of the relief. As a result of processing and analysis of Landsat images at different times, the territory was zoned in terms of the amount of photosynthetically active biomass (NDVI). As a result of zoning, 6 physical-geographical regions and 33 physical-geographical areas were identified.

scholarly journals Impact of sea level rise and shoreline changes in the tropical island ecosystem of Andaman and Nicobar region, India

2021 ◽  
Author(s):  
mageswaran thangaraj ◽  
Sachithanandam V ◽  
Sridhar R ◽  
Manik Mahapatra ◽  
R Purvaja ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Sea Level Rise ◽  
Sea Level ◽  
Remote Sensing Data ◽  
Data Sets ◽  
Andaman Island ◽  
Shoreline Changes ◽  
Digital Elevation ◽  
Analysis System ◽  
Elevation Model

Abstract We report here a four decades of shoreline changes and possible sea level rise (SLR) impact on landuse/landcover (LULC) in Little Andaman Island by using remote sensing (RS) and GIS techniques. A total of six remote sensing data sets covering years between 1976 and 2018 were used to understand the shoreline changes. Moreover, a Digital Shoreline Analysis System (DSAS) was used to estimate short- and long- term shoreline changes from ArcGIS environment. Besides, the Island vulnerability due to SLR was studied through using digital elevation model (DEM). As a result of Sumatra earthquake (2004), the results were showed a significant variation in shorline upliftment and subsidence. The land subsidence was noticed in the range of 1042-3077 ha with sea level rise between 1 and 5 m. Hence, we conclude that Little Andaman Island is vulnerable to SLR and overwhelm low elvation coastal zone.

scholarly journals A new look at the Butic Canal, Egypt

2021 ◽  
Vol 70 (1) ◽  
pp. 29-38
Author(s):  
Robert Schiestl
Keyword(s):  
Remote Sensing ◽  
Roman Empire ◽  
Digital Elevation Model ◽  
Satellite Imagery ◽  
Nile Delta ◽  
Remote Sensing Data ◽  
Historical Sources ◽  
Sensing Data ◽  
Digital Elevation ◽  
Elevation Model

Abstract. The Butic Canal – a Roman period transversal route across the northern Nile Delta – was the longest artificial watercourse in the Nile Delta, yet it remains very poorly understood. To date, the canal has not yet been verified by archeological excavations. The route of the eastern section of the canal has been indirectly identified based on a linear elevated feature most likely representing earth from the excavation of the canal. This study combines the analysis of historical sources and remote sensing data, such as satellite imagery and the TanDEM-X digital elevation model, in order to discuss its date of construction, route, and functions. Based on the data of the digital elevation model, new constructional features are visible in the eastern delta providing the first detailed route of a Roman-era artificial watercourse in Egypt. It is suggested that the canal's construction is placed in the context of imperial investments in the infrastructure of the eastern part of the Roman empire.

scholarly journals МАСШТАБНО-ЗАВИСИМЫЕ ЭФФЕКТЫ В СТРУКТУРЕ ЭКОЛОГИЧЕСКОЙ НИШИ ЛЕБЕДЯ-ШИПУНА CYGNUSOLOR (GMELIN, 1803) В ПЕРИОД ЗИМОВКИ В ПРЕДЕЛАХ ЗАЛИВА СИВАШ

2016 ◽  
Vol 6 (3) ◽  
pp. 234-247
Author(s):  
A. Yu. Andrushenko ◽  
A. V. Zhukov
Keyword(s):  
Remote Sensing ◽  
Ecological Niche ◽  
Random Distribution ◽  
Vegetation Indices ◽  
Remote Sensing Data ◽  
Information Value ◽  
Landsat 8 ◽  
Digital Elevation ◽  
Elevation Model

<p>The assessment of the information value of ecogeographical predictors based on remote sensing data from satellites to reflect features of the ecological niche of the Swan-mute <em>Cygnus up</em> (Gmelina, 1803) in wintering within the Gulf Sivash have been presented. Two groups predictors of ecogeographical landscape data have been considered. The first group is assigned digital elevation model and its derivatives. The second set of classified vegetation indices obtained from Landsat 8 image. Ecological niche has been described using ENFA-procedure. The procedure of random distribution of the pseudo-absent points which range from the presence points restricted by some distance has been applied to assess the role of scale in ecological niche. Ecological niche of Swan mute has been shown to be described in terms of landscape ecogeographical variables. The properties of the ecological niche of the Swan-mute have been found to be depends upon the scale of its consideration. Under various boundary ranges we can get an entirely different, but statistically valid, assess the structure of the ecological niche of the Swan-mute based landscape ecogeographical predictors. The role of the various ecogeographical predictors depending on the scale can vary greatly.</p>

scholarly journals Analysis of tectonic-controlled fluvial morphology and sedimentary processes of the western Amazon Basin: an approach using satellite images and digital elevation model

2007 ◽  
Vol 79 (4) ◽  
pp. 693-711 ◽  
Author(s):  
Clauzionor L. Silva ◽  
Norberto Morales ◽  
Alvaro P. Crósta ◽  
Solange S. Costa ◽  
Jairo R. Jiménez-Rueda
Keyword(s):  
Remote Sensing ◽  
Digital Elevation Model ◽  
Amazon Basin ◽  
Three Dimensional ◽  
Remote Sensing Data ◽  
Sedimentary Processes ◽  
Sensing Data ◽  
Fluvial Morphology ◽  
Digital Elevation ◽  
Elevation Model

An investigation of the tectonic controls of the fluvial morphology and sedimentary processes of an area located southwest of Manaus in the Amazon Basin was conducted using orbital remote sensing data. In this region, low topographic gradients represent a major obstacle for morphotectonic analysis using conventional methods. The use of remote sensing data can contribute significantly to overcome this limitation. In this instance, remote sensing data comprised digital elevation model (DEM) acquired by the Shuttle Radar Topographic Mission (SRTM) and Landsat Thematic Mapper images. Advanced image processing techniques were employed for enhancing the topographic textures and providing a three-dimensional visualization, hence allowing interpretation of the morphotectonic elements. This led to the recognition of main tectonic compartments and several morphostructural features and landforms related to the neotectonic evolution of this portion of the Amazon Basin. Features such as fault scarps, anomalous drainage patterns, aligned ridges, spurs and valleys, are expressed in the enhanced images as conspicuous lineaments along NE-SW, NW-SE, E-W and N-S directions. These features are associated to the geometry of alternated horst and graben structures, the latter filled by recent sedimentary units. Morphotectonic interpretation using this approach has proven to be efficient and permitted to recognize new tectonic features that were named Asymmetric Ariaú Graben, Rombohedral Manacapuru Basin and Castanho-Mamori Graben.

scholarly journals Beach ridges detection on the Dolgaya Spit based on remote sensing data

2021 ◽  
Vol 27 (1) ◽  
pp. 330-338
Author(s):  
Valerii Kulygin ◽  
Samir Misirov
Keyword(s):  
Remote Sensing ◽  
Digital Elevation Model ◽  
Vegetation Cover ◽  
Remote Sensing Data ◽  
Statistical Characteristics ◽  
Beach Ridges ◽  
Sensing Data ◽  
Sparse Vegetation ◽  
Digital Elevation ◽  
Elevation Model

The study of the ridge systems’ morphology on accumulative coastal land forms makes it possible to reconstruct their development. The spatial orientation and height of the beach ridges provide information on the predominance of certain processes at different time intervals. The Dolgaya Spit, which is one of the largest accumulative forms of the Sea of Azov, is characterized by the presence of well-distinguishable generation of sand-shell ridges. The article discusses the possibility of using various remote sensing data to identify beach ridges on the Dolgaya Spit. In this study the data of ground measurements of elevation points performed during the expedition in the summer of 2020 are used. The statistical characteristics of the ridges on the investigated area of the spit are given. The analysis of the possibility of identifying beach ridges on the spit based on high-resolution satellite optical images has been done. It was concluded that it is impossible to unambiguously determine the ridges, since the optical characteristics of the soil and vegetation cover on the Dolgaya Spit do not allow separation of the microrelief forms. The second source of remote sensing data was aerial photography of a part of the Dolgaya Spit using the unmanned aerial vehicle “Phantom 3 PRO”, followed by photogrammetric processing of the obtained digital images. The stages of processing the survey results for the construction of a digital elevation model and an orthomosaic of the investigated area are considered. The quality of the obtained digital elevation model was assessed by comparison with ground measurements of elevation points. The article discusses the source of errors in the obtained digital elevation model. It is noted that the construction of a digital elevation model with acceptable quality is possible only for the spit’s regions with sparse vegetation cover.

scholarly journals Assessing Potential Bioenergy Production on Urban Marginal Land in 20 Major Cities of China by the Use of Multi-View High-Resolution Remote Sensing Data

2021 ◽  
Vol 13 (13) ◽  
pp. 7291
Author(s):  
Ben Zhang ◽  
Jie Yang ◽  
Yinxia Cao
Keyword(s):  
Remote Sensing ◽  
High Resolution ◽  
Remote Sensing Data ◽  
Landscape Patterns ◽  
Marginal Land ◽  
Bioenergy Production ◽  
Digital Elevation ◽  
Fine Spatial Resolution ◽  
Elevation Model ◽  
Digital Elevation Model Data

For the purpose of bioenergy production, biomass cropping on marginal land is an appropriate method. Less consideration has been given to estimating the marginal land in cities at a fine spatial resolution, especially in China. Marginal land within cities has great potential for bioenergy production. Therefore, in this research, the urban marginal land of 20 representative cities of China was estimated by using detailed land-cover and 3D building morphology information derived from Ziyuan-3 high-resolution remote sensing imagery, and ancillary geographical data, including land use, soil type, and digital elevation model data. We then classified the urban marginal land into “vacant land” and “land between buildings”, and further revealed its landscape patterns. Our results showed that: (1) the suitable marginal land area ranged from 17.78 ± 1.66 km2 to 353.48 ± 54.19 km2 among the 20 cities; (2) it was estimated that bioethanol production on marginal land could amount to 0.005–0.13 mT, corresponding to bioenergy of 2.1 × 1013–4.0 × 1014 J for one city; (3) from the landscape viewpoint, the marginal landscape pattern tended to be more fragmented in more developed cities. Our results will help urban planners to reclaim unused urban land and develop distributed bioenergy projects at the city scale.

scholarly journals Toward a High-Definition Remote Sensing Approach to the Study of Deserted Medieval Cities in the Near East

Geosciences ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 369 ◽  
Author(s):  
Lenka Starková
Keyword(s):  
Remote Sensing ◽  
Feature Detection ◽  
Remote Sensing Data ◽  
Urban Site ◽  
Small Scale ◽  
High Definition ◽  
Fine Grained ◽  
Digital Elevation ◽  
Multi Temporal ◽  
Elevation Model

The variability of currently available remote sensing datasets raises the question of which specific processing methods should be used for feature detection and feature extraction in both large and small-scale overhead images. In some cases, particular analyses allow us to carry out feature detection much more easily and effectively. The high-definition approach enables enhanced analysis of remote sensing data using all the spectral and graphical potential of multi-temporal ordered components. The deserted urban site of Kona Makhmūr, Iraqi Kurdistan, is taken as a case study to demonstrate this fine-grained approach. The analysis described in this paper is based on the complementary use of a variety of overlayed imagery, augmented by data from terrestrial surveys. The resulting map substantially enhances our knowledge of the built environment and the economic and environmental conditions of this early Islamic-period site. Spectral analysis of raster images allowed us to detect the real shapes of features, and with the addition of digital elevation model (DEM) (created via unmanned aerial system (UAV)) we were also able to interpret the state of preservation of the overground relics and the diachronic dynamics of their degradation.

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