Earth Mapping Research Articles

A Global Evaluation of Radar‐Derived Digital Elevation Models: SRTM, NASADEM, and GLO‐30

AbstractThis study evaluates global radar‐derived digital elevation models (DEMs), namely the Shuttle Radar Topography Mission (SRTM), NASADEM and GLO‐30 DEMs. We evaluate their accuracy over bare‐earth terrain and characterize elevation biases induced by forests using global Lidar measurements from the Ice, Cloud, and Land Elevation Satellite (ICESat)'s Geoscience Laser Altimeter System (GLAS), the Global Ecosystem Dynamics Investigation (GEDI) and the ICESat‐2 Advanced Topographic Laser Altimeter System (ATLAS) instruments collected on locally flat terrain. Our analysis is based on error statistics calculated for each DEM tile, which are then summarized as global error percentiles, providing a regional characterization of DEM quality. We find NASADEM to be a significant improvement upon the SRTM V3. Over bare ground areas, the mean elevation bias and root mean square error (RMSE) improved from 0.68 to 2.50 m respectively to 0.00 and 1.5 m as compared to ICESat/GLAS. GLO‐30 is more accurate with bare ground elevation bias and RMSE were below 0.05 and 0.55 m. Similar improvements were observed when compared to GEDI and ICESat‐2 measurements. The DEM biases associated with the presence of vegetation vary linearly with canopy height, and more closely follow the percentile of Lidar Relative Height (RH50). Other factors such as canopy density, radar frequency and Lidar technology also contribute to observed elevation biases. This global analysis highlights the potential of various technologies for mapping of Earth's topography, and the need for more advanced remote sensing observations that can resolve vegetation structure and sub‐canopy ground elevation.

Cartografía temática y recursos TIC en la enseñanza y aprendizaje de la Geografía regional de Europa

In this article, we present a classroom experience with university students in training to be secondary school geography teachers. It is based on a didactic proposal using thematic cartography (Eurostat, ESPON, ESPON-SIESTA and the Information Society Atlas in Galicia) and ICT resources (statistical sources, free picture banks, aerial photography, Google Earth and Google Maps). The proposal´s aim is to use contents from the regional geography of Europe as a base or starting point to show a series of didactic recommendations for the teaching and learning of geography and social sciences. What is more, everything is with a clear idea, from a descriptive and rote geography to an active and critical geography, in which students participate in the construction of knowledge and increase their ability to reflect on geographical issues. The results of the experience will highlight the value of these tools in secondary education. We had also previously assessed the presence of thematic cartography and ICT resources within the required official Galicia curriculum to teach geography in compulsory secondary education. The idea is to deepen the value of the curriculum in didactic code, to know what tools it offers, how it offers them and with what intentions. This solution, among other opportunities, will allow us to identify a curriculum offering a specific teaching model. On the other hand, it will also give us the opportunity to firmly rebuke all the proposals considered to be erroneous, repetitive, or of little didactic value.

ВЛИЯНИЕ ИЗМЕНЕНИЯ КЛИМАТА НА ПАСТБИЩНЫЕ ЭКОСИСТЕМЫ АТЫРАУСКОЙ ОБЛАСТИ РЕСПУБЛИКИ КАЗАХСТАН

Grasslands are an important and vulnerable resource among many ecosystems that occupy a large part of the earth's surface. These ecosystems are constantly exposed to various climatic factors, and climate change is becoming one of the main threats to them. Pastures occupy 9612.9 thousand hectares of the territory of Atyrau oblast, which is 81% of the total territory. These lands are an important source for livestock breeding. In this paper we assessed the potential impact of climate change on pasture ecosystems of Atyrau oblast of the Republic of Kazakhstan. The spatial and temporal variability of precipitation for 30 years (1992-2022) was investigated using meteorological data. The fluctuations of precipitation amount in vegetation period (April - September) for 1992-2022 were determined. Multiyear series of average annual air temperature and precipitation during vegetation vegetation period were analysed and their predicted cyclic fluctuations for the next two years were modelled. Degradation points of pasture ecosystems were identified by counting 622 points in 1992, 585 points in 2002, 412 points in 2012 and 387 points of former and current cattle stands in 2022 through Google Earth map. The heat and moisture availability of the growing season of pasture plants under climate change was predicted. The results of this study show how increasing temperature, decreasing precipitation, and management history affect pasture quality, and highlight the important role of vegetation of rangeland ecosystems. The results can be used in the process of establishing effective rangeland management practices, mechanisms for adaptation of rangeland vegetation or ecosystems to climate change.

Improving the performance of evidential belief function model using five machine learning models in earth fissure susceptibility mapping

The frequency and occurrence of earth fissures threaten human settlements, infrastructure, and agricultural lands in many parts of the globe. This natural hazard has particularly posed great challenge in the North, Central, and Eastern parts of the Najaf Abad Basin of Iran. This paper presents a comparative analysis of machine learning algorithms for earth fissure susceptibility assessment, and involves the creation of an earth fissure database by selecting and validating 200 fissure locations. To improve the accuracy of the fissure locations, various geographic data sources, such as Google Earth images, field surveys, and GPS measurements, were employed. The locations were divided into training and validation sets based on sixteen conditioning factors for finding the earth fissure susceptible zones using EBF (Evidential belief function), EBF – Multilayer Perceptron (MLP), EBF – Function Tree (FT), EBF – Alternating decision tree (ADtree), EBF – Adaptive Boosting (AdaBoost), EBF – Random SubSpace (RSS), EBF – Naive Bayes Tree (NBTree) models. The results show that earth fissures occur in greater concentrations where groundwater levels are lowest, and their prevalence is closely associated to both agricultural activities and the presence of clay, clayey sand, and silty clay soils. Susceptibility analysis results revealed that 15–21 % agricultural dependent population falls under the very high susceptibility risk zone in and around the major cities of the Najaf Abad region. The receiver operating characteristic (ROC) curve analysis showed that the EBF-RSS algorithm has higher accuracy (>99 %) compared to other algorithms (>85 %) in training and validation phases for earth fissure susceptibility prediction. Our findings emphasise the need to prioritise these susceptible areas for sustainable land and water management strategies and implement effective measures to mitigate the impact of earth fissures. Our study also advances our knowledge on geospatial analysis and earth fissures-related hazard assessment by applying five machine learning algorithms that shows spatial similarity in susceptibility categories with splendid accuracy performance.

Assessment of Technical and Financial Feasibility of the Gadachaur Lift Irrigation System, Bajura Nepal

Implementation of a cost-effective and technically feasible irrigation project in the hilly topography contains many challenges in operation and management. This study examined the technical and economic feasibility of the lift irrigation system along with diversification of irrigated agriculture in one of the mid-hill districts of Nepal. To achieve the overall aim, a case study was conducted in Gadachaur, Bajura District of Nepal in 2022-2023. The approach consisted of collecting data and information from desk study of Google Earth maps, field visits, surveys, focus group discussions and subsequent ,interpretation. The study found that the selected system is both technically and economically feasible. The cropping intensity in the chosen area was 105%. The economic analysis indicated that the internal rate of return was 19.7%, and the B/C ratio at a 10% discount was 1.9, while at a 12% discount rate, the B/C was 1.63. After establishing the technical feasibility of the irrigation system, the following recommendations were made; the economic size of the pumping main should be 80 mm, the total dynamic head should be 160 m, the total volume of water to be pumped per day should be 141 m3, and the HP of the pump required should be 15 KW.

Strategic Deployment of Ducklink Wireless Devices for Disaster Mitigation and Management in Nueva ECIJA University of Science and Technology Sumacab Campus

A significant challenge during disasters is the breakdown of traditional communication systems, impeding rescue operations and information dissemination. To tackle this issue, researchers conducted a study on strategically deploying DuckLink wireless devices within a small community, particularly at NEUST Sumacab Campus. Utilizing tools like Google Maps, Google Earth, and WiFi Heat Map, optimal locations for device placement were identified. Analyzing signal range and performance characteristics, the study endeavored to enhance disaster management capabilities on campus. Findings revealed DuckLink devices operate with omnidirectional polarity, ensuring reliable communication, with a clear correlation between distance and message transmission time emphasizing strategic device placement for efficient campus-wide connectivity. Recommending the installation of 112 devices across 79 buildings, with key locations designated for Papaduck receivers and Mamaduck transmitters, this research offers crucial insights into disaster management strategies, optimizing wireless communication infrastructure in educational environments, thus contributing to safer and more resilient communities.

Overview of Fault Zones Based on Remote Sensing Data as Contribution to the Safety of Infrastructure and Land Use in Southern Egypt

Part of a requisite for natural hazard awareness and damage prevention in Egypt is the detailed monitoring of surface fault zones. The inventory of active faults and their risk assessment is an essential contribution to the safety of settlements, land use and infrastructure (railroads, highways, pipelines) and to damage prevention. Thus, this study aims to contribute to the detection, inventory, and documentation of fault zones. Surface faulting hazard assessment considers any surface consequences caused by surface near faults such as abrupt horizontal and vertical displacements and rotations, or mass movements after stronger earthquakes. Long-term, aseismic, slow-creeping movements along fault zones have to be considered as well. Southern Egypt offers unique and optimal conditions for the research of fault zones and their different structural expressions and conditions because of the dry desert climate conditions and relatively low human influence on the landscape in extended areas, especially for the investigation of different types of faults, their interactions with each other and the outcropping rocks, and fault-related deformation structures. Volcanic activity has been influenced in the geologic past often by larger fault zones as dike intrusions, volcanic cones and plugs or craters occur concentrated along these zones of weakness facilitating the uprise of magma. Larger fault zones are crossing reservoir areas. Surface water intrusions into deep-seated faults have played a role in triggering earthquake swarms in the reservoir areas during the last decades. Mapping of active faults is not only an important but also a cost-intense task when carried out in the field or when using geodetic and geophysical data. In the scope of this study, fault detection was carried out based on different open-source satellite data (Landsat 8 and 9, Sentinel 2 optical data, Sentinel 1 and ALOSPASAR radar data, and Google Earth and Bing Map high-resolution satellite images) from the southern part of Egypt. Faults were digitized using ArcGIS and QGIS software. An inventory of fault-related structural features (depressions, ridges, rotation structures, etc.) and rift zones was elaborated based on remote sensing data. An overview of different types of faults and their related structures as well as their interactions with their host rock conditions could be achieved. By merging the inventory results with infrastructural and land use data, critical areas with potential damage risk were pointed out.

Emissivity of the Earth as a Cancer Predictor

Aim: The anticancer properties of locally applied infrared radiation are widely discussed in the literature. Earth's global emissivity, or the infrared radiation emitted by our planet, is inhomogeneous and varies based on the geophysical characteristics of the region where one resides. This study aimed to test the hypothesis: does local emissivity influence the prevalence of malignant diseases in a region. Materials and Methods: We performed planimetric comparison of two World maps: 1. NASA Spacecraft Map of Earth's Global Emissivity; 2. GLOBOCAN 2020 Global Cancer Data. For comparison we used “Image Compare” tool from Oxford Robotics Research Group. For the area measurements we used FreeMapsTools calculator. Results: The total assessed area was 127,750,000 square kilometers. The distribution according to emissivity was as follows: 107,050,000 km² of area with emissivity above 0.94 and 20,700,000 km² of area with emissivity below 0.94. The distribution according to cancer incidence was as follows: 28,150,000 km² of area with cancer incidence lower than 180 per 100,000 and 99,600,000 km² of area with cancer incidence more than 180 per 100,000. Cancer incidence was found to be statistically significantly associated with higher emissivity of the defined area (p-value < 0.0001). Conclusion: We found a significant association between areas of higher emissivity on our planet and higher cancer incidence. Our findings underscore the need to include environmental factors, in our case infrared radiation exposure, as potential predictor in the deployment of cancer predictive models, such as those involving machine learning and artificial intelligence.

Correlation Fractal Dimension Analysis Mountainous Traditional Village Settlement Spatial Form –Case Study of Qiandongnan in Guizhou

Objective: A study carried out in the traditional villages of Qiandongnan in Guizhou province, located in China, to portray 409 traditional villages’ spatial distribution and fractal charicteristic, as well as its implications for the preservation of the group of traditional villages. Theoretical framework: From previous research, traditional village quantitative research on spatial area focuses on the statistics of mathematical models and spatial analyses of GIS, which indirectly reflect the complexity of the spatial patterns of traditional villages. Therefore, applying fractal theory to the spatial complexity of villages can provide a relatively objective and direct assessment for studying traditional villages with different formation backgrounds. Method: Data were collected in Google Earth map data and spatial data were obtained, which were synthesized and analyzed using spatial, statistical and mathematics analysis to verify the distribution factors and know about villages’ spatial fractal characteristics. Results and conclusion: The mountain settlements in Qiandongnan are concentrated in Leishan based on the Miao national group and “Liping-Congjiang-Rongjiang” based on the Dong national group. The q values of the explanatory power of each factor for the spatial distribution of traditional villages in the Qiandongnan area are, in descending order, intangible cultural heritage > GDP > distance from roads > height > the proportion of ethnic minorities > urbanization rate > average annual temperature > average annual precipitation > distance to rivers. Research implications: Villages contribute significantly to the enhancement of traditional Chinese culture, especially the preservation of historical buildings and distinctive local cultures. Furthermore, Knowing the factors of traditional village centralized contiguous protection mode and rural planning based on the policy of rural revitalization in China. Originality/value: Collected traditional villages’ distribution data from the official website and marked on the Google Earth map. Spatial analysis distribution of villages and emphasizes the importance of spatial correlation analysis in understanding the relationship between land use and rural population distribution.

Distinguishing the Intervalley Plain from the Intermountain Flat for Landform Mapping Using the Sightline Algorithm

The intervalley plain is an important type of landform for mapping, and it has good connectivity for urban construction and development on the Loess Plateau. During the global landform mapping of the Deep-time Digital Earth (DDE) Big Science Program, it was found that slope and relief amplitude hardly distinguished intervalley plains from intermountain flats. This study established a novel descriptive method based on a digital elevation model to describe the difference between intervalley plains and intermountain flats. With the proposed method, first the pattern of variation in the elevation angle is described using a sight line on the terrain profile, and the lowest elevation angle (LEA) is extracted. The maximum value of the LEA is subsequently used among multiple terrain profiles to represent the maximum velocity of the elevation decrease, that is, the three-dimensional lowest elevation angle (3D LEA), to represent the intervalley plains with lower 3D LEA values. The sight parameters of the 3D LEA are evaluated to optimize the intervalley plain mapping. The functional mechanism of the sight parameters is presented from a mathematical perspective and a comparative analysis of the 3D LEA is performed for the relief amplitude and slope angle at multiple scales. This study explores sight-line analysis in a novel way, providing a new terrain factor for landform mapping involving intervalley plains.

A Geostratigraphic Map of the Rachmaninoff Basin Area: Integrating Morphostratigraphic and Spectral Units on Mercury

AbstractGeological maps of Earth typically incorporate field observations of rock lithology, structure, composition, and more. In contrast, conventional planetary geological maps are often made using primarily qualitative morphostratigraphic remote sensing observations of planetary surfaces. However, it is possible to define independent quantitative spectral units (SUs) of planetary surfaces, which potentially contain information about surface composition, grain size, and space weathering exposure. Here, we demonstrate a generic method to combine independently derived geomorphic and SUs, using the Rachmaninoff basin, Mercury, as an example to create a new geostratigraphic map. From this geostratigraphic map, we can infer some compositional differences within geomorphic units, which clarifies and elaborates on the geological evolution of the region.

Granite Exposure Mapping Through Sentinel‐2 Visible and Short Wave Infrared Bands

AbstractNonmetallic minerals like granite and limestone have calcite and biotitic ingredients as their major part which exhibit wonderful absorption features in the visible and short wave range of the electromagnetic spectrum. This research puts emphasis on delineating granite and limestone deposits of the Mardan district through the latest multispectral Landsat‐9 and Sentinel‐2 sensors of which the latter provided 94% mapping accuracy in delineating granites (biotitic bearing minerals) and limestone (calcite‐bearing minerals). The Image processing techniques of minimum noise fraction, which is double cascaded principal components analysis and pixel purity index algorithms proved helpful to bring significant improvements in classification results and in the reduction of noise and data size. The outcomes of the research study show that supervised machine learning algorithms are impactful to map such minerals provided that the data must be well organized and limited in size. The results achieved were verified through validation steps like, (a) Independent reference data of high‐resolution Google Earth maps and (b) Ground survey reports. Arc GIS 10.2 and Envi 5.3 software suite were used to create (a) ground truth points at random for accuracy assessment (b) portraying study area maps (c) Image Processing and Preprocessing tools and (d) implementation of machine learning algorithms. Access to the data and software suite is being provided for open research work.

Floodplain mapping of an ungauged river: A case study on Seti River in Pokhara, Nepal

Settlements and infrastructures along the banks of Seti River in Pokhara, Nepal are at high risk of flood. Floodplain mapping for ungauged Seti River is not straightforward like the one for gauged rivers. Main goal of this study was to prepare floodplain maps along the ungauged Seti River in Pokhara, as a case study, using one-dimensional HEC-RAS model. First, catchment area ratio (CAR) method was applied to find annual flow in ungauged Seti River based on flow data of gauged Mardi station. Once the annual maximum flow was estimated for sufficient time length (i.e., 42 years), peak flood was predicted using Gumbel method for various reaches of Seti River within Pokhara. Thus, estimated peak floods were also compared with the peak floods predicted using Gumbel method based on the annual flow data of Tanahu station. As the specific discharge observed to be comparable with each other (difference ≤ 2.68%), CAR method found be a reliable one that is useful for ungauged river. Then, Cowan’s approach was applied to estimate Manning’s roughness coefficient (n) and used it for calibration of HEC-RAS model. Cowan approach found to be a best alternative for ungauged river as the comparison of modelled flow depth with measured flow depth yielded only 3.82% difference. Finally, 1D hydraulic modelling was performed using calibrated HEC-RAS model with available 12.5 m resolution DEM terrain data. Floodplain maps were prepared based on the HEC-RAS simulation results coupled with Google Earth map. The flood inundation area within Pokhara was found to be 2.76, 3.05, and 3.59 Km2 for the peak flood of 20, 50, and 100 years return periods, respectively. Moreover, Laltin Bazar and Gaighat areas were identified to be at high risk of flood such that these areas found to be inundated with 20 or greater years return period floods, compared to Ramghat area which was observed to be flooded with the peak flood of 50 or more years return period. Floodplain maps of this study could be used for preparing flood hazard maps, planning infrastructures, and flood management.

Tilings of the sphere by congruent quadrilaterals III: Edge combination a 3 b with general angles

Abstract Edge-to-edge tilings of the sphere by congruent quadrilaterals are completely classified in a series of three papers. This last one classifies the case of a 3 ⁢ b {a^{3}b} -quadrilaterals with some irrational angle: there are a sequence of 1-parameter families of quadrilaterals admitting 2-layer earth map tilings together with their basic flip modifications under extra condition, and 5 sporadic quadrilaterals each admitting a special tiling. A summary of the full classification is presented in the end.

A metrological reflection on uncertainty about the use of maps instead of global parameters

Recently, there has been an abnormal use of global parameters not only in economical fields, but also in scientific ones, like meteorology and climate. They are supposed to convey in a clear way the most important significance in the changes of numerical parameters. However, synthetic global parameters may miss the complexity of the issue that they are intended to qualify, so that trivializing their meaning. The paper discusses the fact that this effect is more than trivialization because the evaluation of a map, e.g. an Earth map, which is often contrasted, is less sensitive to the uncertainty that shall always be associated with any type of information, namely the numerical one, when the uncertainty evaluation is associated with the parameter value. In most cases, and especially when the map shows a great variety of situations, a visual examination allows, even to a scientist, different methods for a more reliable evaluation. General cases are reported to exemplify the above statement.

Re-evaluating falls through skylights in the USA: has anything changed?

Purpose With proper design and work planning, falls through fragile skylights are preventable. Skylights pose a hazard to workers when their work tasks for operations, maintenance and repair require them to be on roofs. The National Institute of Occupational Health and Safety produced guidelines and special alerts to address the dangers that are present around skylights, and the Occupational Safety and Health Administration regulations have prescriptive requirements for work performed around skylights, and yet incidents still occur. The purpose of this study is to investigate and raise awareness for the causality of the incidents involving skylights in the USA. Design/methodology/approach The authors investigated and analyzed 204 incidents involving skylights recorded by the Bureau of Labor Statistics to characterize their nature and to determine any correlation with the roof environment or the nature of the work performed. Using Google Earth and Google Maps roof geometry, proximity of skylights to roof edge and rooftop mechanical equipment was determined. Findings The majority of falls through skylights occur during roof maintenance and repair activities. Falls through skylights are underreported. Because of a general lack of good design to reduce or eliminate the risk of falling through skylights, facility managers carry the burden to properly assess work and access on roofs where fragile skylights are present. Originality/value The phenomenon of falling through skylights was made aware on a national level in the USA in 1989; however, little has been done from a design and planning perspective to reduce these incidents. This paper presents a unique perspective on the role of facility managers in understanding the hazards associated with roof maintenance near skylights.

Determination of horizontal deformation of the Earth`s crust on the territory of Ukraine based on GNSS measurements

The purpose of research is to identify horizontal deformation of the Ukraine territory, using only proven and suitable for geodynamic interpretation GNSS stations. The initial data are observations from 30 GNSS stations for 2017 to 2020. Methodology. The methodology includes the analysis of modern Earth's crust deformations of Ukraine. As a result, for the first time the impact of the coordinates time series created by two different methods: Precise Point Positioning (PPP) and the classical differential method, on determining deformation processes was analysed. It was established that nowadays for the tasks of monitoring, including geodynamic, it is necessary to use the Precise Point Positioning (PPP) method, because the accuracy of determined velocities of the GNSS stations by this method was higher than in the classical differential method. Results. A map of horizontal Earth's crust deformations on the territory of Ukraine was created according to the coordinates time series of GNSS stations. The extension areas of Shepetivka-Starokostiantyniv Khmelnytsky region, Boryspil- Pryluky-Pereyaslav-Khmelnitsky Kyiv and Chernihiv region, as well as a compression area of the Earth's crust in Nizhyn - Stepovi Khutory - Kozelets of Chernihiv region was identified. Additionally, a map of horizontal displacements of the GNSS-stations was created, where the diverse of these displacements was observed, which is likely to be caused by the presence of modern subvertical and sub-horizontal faults and fault areas. For better interpretation of the obtained results, it is necessary to involve geological and geophysical data of tectonic activity of the Ukraine territory.

Critical Minerals for a Carbon-Neutral Future

The Earth Mapping Resources Initiative is filling data gaps and fostering more holistic understanding of critical mineral resources in the United States using a novel mineral systems framework.

TILINGS OF THE SPHERE BY CONGRUENT QUADRILATERALS II: EDGE COMBINATION WITH RATIONAL ANGLES

AbstractEdge-to-edge tilings of the sphere by congruent quadrilaterals are completely classified in a series of three papers. This second one applies the powerful tool of trigonometric Diophantine equations to classify the case of $a^3b$ -quadrilaterals with all angles being rational degrees. There are $12$ sporadic and $3$ infinite sequences of quadrilaterals admitting the two-layer earth map tilings together with their modifications, and $3$ sporadic quadrilaterals admitting $4$ exceptional tilings. Among them only three quadrilaterals are convex. New interesting non-edge-to-edge triangular tilings are obtained as a byproduct.

Dynamic development of the Athabasca Valles outflow system from volcanic facies and 15 m scale roughness

Surface roughness properties provide context for geologic terrains, and are commonly partnered with field-based mapping on Earth and satellite-based photogeologic mapping in planetary sciences. In this study, we combine morphology-based facies mapping and perform quantitative roughness analysis and characterization of facies for the Athabasca Valles lava flow-field on Mars to identify flow features, provide insight into eruption conditions, and link roughness patterns throughout the flow to emplacement conditions. The root-mean-square (RMS) height and effective slope were acquired at 15 m wavelength for 14 unique lava facies using statistically derived components from the Shallow Radar (SHARAD) surface echo strength. Quantitative RMS height surface roughness of Athabasca lava features range from 1.09 m to 1.76 m. We show that the RMS height response is generally consistent with facies transitions, confirming the linkage between surficial morphologies and lava flow roughness, including the ability to constrain the relative spatial and temporal evolution of emplacement processes. Roughness patterns and facies localities suggest that the emplacement of Athabasca lava experienced a dynamic progression of local discharge surges and substrate influence on morphology. Given a more complete view of the surface statistical properties, our analyses of nadir-looking radar tracks prove to be a useful tool to distinguish between transitional lava facies.