scholarly journals Quantitative Analysis of Anthropogenic Morphologies Based on Multi-Temporal High-Resolution Topography

2019 ◽  
Vol 11 (12) ◽  
pp. 1493 ◽  
Author(s):  
Jie Xiang ◽  
Shi Li ◽  
Keyan Xiao ◽  
Jianping Chen ◽  
Giulia Sofia ◽  
...  
Keyword(s):  
High Resolution ◽  
Environmental Planning ◽  
Driving Forces ◽  
Earth Science ◽  
Small Scale ◽  
Natural Area ◽  
Natural Processes ◽  
Geomorphic Features ◽  
Multi Temporal ◽  
Science Community

Human activities have reshaped the geomorphology of landscapes and created vast anthropogenic geomorphic features, which have distinct characteristics compared with landforms produced by natural processes. High-resolution topography from LiDAR has opened avenues for the analysis of anthropogenic geomorphic signatures, providing new opportunities for a better understanding of Earth surface processes and landforms. However, quantitative identification and monitoring of such anthropogenic signature still represent a challenge for the Earth science community. The purpose of this contribution is to explore a method for monitoring geomorphic changes and identifying the driving forces of such changes. The study was carried out on the Eibar watershed in Spain. The proposed method is able to quantitatively detect anthropogenic geomorphic changes based on multi-temporal LiDAR topography, and it is based on a combination of two techniques: the DEM of Difference (DoD) and the Slope Local Length of Auto-correlation (SLLAC). First, we tested the capability of the SLLAC and derived parameters to distinguish different types of anthropogenic geomorphologies in 5 study case at a small scale. Second, we calculated the DoD to quantify the geomorphic changes between 2008 and 2016. Based on the proposed approach, we classified the whole basin into three categories of geomorphic changes (natural, urban or mosaic areas). The urban area had the most clustered and largest geomorphic changes, followed by the mosaic area and the natural area. This research might help to identify and monitoring anthropogenic geomorphic changes over large areas, to schedule sustainable environmental planning, and to mitigate the consequences of anthropogenic alteration.

scholarly journals GEOMORPHOLOGICAL MAPPING WITH TERRESTRIAL LASER SCANNING AND UAV-BASED IMAGING

2016 ◽  
Vol XLI-B5 ◽  
pp. 591-597 ◽  
Author(s):  
N. Tilly ◽  
D. Kelterbaum ◽  
R. Zeese
Keyword(s):  
High Resolution ◽  
Laser Scanning ◽  
Low Cost ◽  
Terrestrial Laser Scanning ◽  
Small Scale ◽  
Data Sets ◽  
Geomorphological Mapping ◽  
3D Data ◽  
Multi Temporal ◽  
Mean Differences

High-resolution digital elevation models (DEMs) are useful for the detailed mapping of geomorphological features. Nowadays various sensors and platforms are available to collect 3D data. The presented study compares terrestrial laser scanning (TLS) and low-cost unmanned aerial vehicles (UAV)-based imaging in terms of their usability for capturing small-scale surface structures. In October 2014 and June 2015 measurements with both systems were carried out in an episodically water-filled karst depression under pasture farming in the region of Hohenlohe (Southwest Germany). The overall aims were to establish high-resolution DEMs and monitor changes of the relief caused by dissolution and compare the advantages and drawbacks of both systems for such studies. Due to the short time between the campaigns the clear detection of temporal changes was hardly possible. However, the multi-temporal campaigns allowed an extensive investigation of the usability of both sensors under different environmental conditions. In addition to the remote sensing measurements, the coordinates of several positions in the study area were measured with a RTK-DGPS system as independent reference data sets in both campaigns. The TLS- and UAV-derived DEM heights at these positions were validated against the DGPS-derived heights. The accuracy of the TLS-derived values is supported by low mean differences between TLS and DGPS measurements while the UAV-derived models show a weaker performance. In the future years additional simultaneous measurements with both approaches under more similar vegetation conditions are necessary to detect surface movements. Moreover, by investigating the subsurface the interaction of above and below ground processes might be detected.

scholarly journals Sliding Windows Method Based on Terrain Self-Similarity for Higher DEM Resolution in Flood Simulating Modeling

2021 ◽  
Vol 13 (18) ◽  
pp. 3604
Author(s):  
Qian Yin ◽  
Ziyi Chen ◽  
Xin Zheng ◽  
Yingjun Xu ◽  
Tianxue Liu
Keyword(s):  
High Resolution ◽  
Earth Science ◽  
Small Scale ◽  
Self Similarity ◽  
Flood Simulation ◽  
Sliding Windows ◽  
Practical Applications ◽  
Digital Elevation ◽  
Elevation Model ◽  
Matching Window

A digital elevation model (DEM) is a quantitative representation of terrain and an important tool for Earth science and hydrological applications. A high-resolution DEM provides accurate basic Geodata and plays a crucial role in related scientific research and practical applications. However, in reality, high-resolution DEMs are often difficult to obtain. Due to the self-similarity present within terrains, we proposed a method using the original DEM itself as a sample to expand the DEM using sliding windows method (SWM) and generate a higher resolution DEM. The main processes of SWM include downsampling the original DEM and constructing mapping sets, searching for the optimal matching, window replacement. Then, we repeat these processes with the small-scale expansion factor. In this paper, the grid resolution of the Taitou Basin was expanded from 30 to 10 m. Overall, the superresolution reconstruction results showed that the method could achieve better outcomes than other commonly used techniques and exhibited a slight deviation (root mean square error (RMSE) = 3.38) from the realistic DEM. The generated high-resolution DEM prove to be significant in the application of flood simulation modeling.

scholarly journals Problems of geotourism and geodiversity

2012 ◽  
Vol 31 (3) ◽  
pp. 57-61 ◽  
Author(s):  
Clifford Ollier
Keyword(s):  
Earth Science ◽  
National Geographic ◽  
A Value ◽  
The Earth ◽  
Geomorphic Features ◽  
Science Community ◽  
Value Judgement

Abstract. Early definitions of geotourism stressed tourism related to geology and geomorphology, though some drifted into other concepts such as education, sustainability, conservation and more. Later definitions, largely fostered by National Geographic, treat the topic as related to geography, or more simply place, and concentrate on the extraneous topics such as sustainability, conservation and so forth which should be part of any form of tourism. The earth science community is liable to lose its influence on creation and interpretation of geosites and related topics because the concept has been broadened to include everything. Geodiversity is a copy-cat adaptation of biodiversity, but while biodiversity might be a measure of the health of an ecosystem, the value of geological and geomorphic sites does not depend on diversity. Many geological and geomorphic features are restricted to a single rock or feature, which enhances their value. Geodiversity might be useful as a way of recording diverse features within a given area, but it should not be treated as a value-judgement on the significance of individual sites. The whole area of geoheritage is under threat from the redefinition of geotourism, and the mis-application of the concept of geodiversity

scholarly journals GEOMORPHOLOGICAL MAPPING WITH TERRESTRIAL LASER SCANNING AND UAV-BASED IMAGING

2016 ◽  
Vol XLI-B5 ◽  
pp. 591-597 ◽  
Author(s):  
N. Tilly ◽  
D. Kelterbaum ◽  
R. Zeese
Keyword(s):  
High Resolution ◽  
Laser Scanning ◽  
Low Cost ◽  
Terrestrial Laser Scanning ◽  
Small Scale ◽  
Data Sets ◽  
Geomorphological Mapping ◽  
3D Data ◽  
Multi Temporal ◽  
Mean Differences

High-resolution digital elevation models (DEMs) are useful for the detailed mapping of geomorphological features. Nowadays various sensors and platforms are available to collect 3D data. The presented study compares terrestrial laser scanning (TLS) and low-cost unmanned aerial vehicles (UAV)-based imaging in terms of their usability for capturing small-scale surface structures. In October 2014 and June 2015 measurements with both systems were carried out in an episodically water-filled karst depression under pasture farming in the region of Hohenlohe (Southwest Germany). The overall aims were to establish high-resolution DEMs and monitor changes of the relief caused by dissolution and compare the advantages and drawbacks of both systems for such studies. Due to the short time between the campaigns the clear detection of temporal changes was hardly possible. However, the multi-temporal campaigns allowed an extensive investigation of the usability of both sensors under different environmental conditions. In addition to the remote sensing measurements, the coordinates of several positions in the study area were measured with a RTK-DGPS system as independent reference data sets in both campaigns. The TLS- and UAV-derived DEM heights at these positions were validated against the DGPS-derived heights. The accuracy of the TLS-derived values is supported by low mean differences between TLS and DGPS measurements while the UAV-derived models show a weaker performance. In the future years additional simultaneous measurements with both approaches under more similar vegetation conditions are necessary to detect surface movements. Moreover, by investigating the subsurface the interaction of above and below ground processes might be detected.

FATORES CONDICIONANTES E DESENCADEANTES DE QUEDAS DE BLOCOS NA BACIA HIDROGRÁFICA DO RIACHO TRAPIÁ, SOBRAL, CEARÁ, BRASIL

2019 ◽  
Vol 21 (2) ◽  
pp. 393-412
Author(s):  
Adisson Souza Tavares ◽  
Frederico De Holanda Bastos ◽  
Yuri Da Silva Belarmino
Keyword(s):  
Data Collection ◽  
Environmental Planning ◽  
Field Research ◽  
Risk Mapping ◽  
Dynamics Analysis ◽  
Natural Processes

As quedas de blocos são processos naturais, classificadas como eventos geomorfológicos perigosos ao homem a partir dos impactos que podem causar sobre as populações que vivem em encostas susceptíveis. O seu deflagro está submetido à influência de diversos fatores que possuem diferentes funções e dinâmicas. Os agentes geológicos, geomorfológicos, pedológicos, fitogeográficos, hidroclimáticos e antrópicos desencadeiam e condicionam os fenômenos, implicando na mudança de sua estrutura, velocidade e duração. De acordo com a classificação de Garcia (2012), este trabalho objetiva identificar os agentes condicionantes e desencadeantes de quedas de blocos, na bacia hidrográfica do Riacho Trapiá, localizada na vertente sul da Serra da Meruoca, noroeste do Ceará. Os passos metodológicos foram: levantamento bibliográfico e cartográfico, técnicas de geoprocessamento, pesquisa de campo e integralização dos dados. Entende-se que os diferentes fatores que levam à ocorrência de quedas de blocos podem ser agrupados em dois conjuntos, sendo eles condicionantes, que levam a predisposição ao início das quedas, e os desencadeantes, que são dinâmicos e iniciam diretamente os processos morfodinâmicos. Logo, a presente análise pode servir de base para diversos tipos de estudos sobre temáticas geomorfológicas, a exemplo das análises de dinâmicas de vertentes, cartografia de risco, planejamento ambiental, ou gestão de bacias hidrográficas.Palavras-chave: Morfodinâmica; Susceptibilidade Geomorfológica; Quedas de Blocos. ABSTRACTRockfalls are natural processes, classified as geomorphological events dangerous to man from the impacts they can cause on populations living on susceptible slopes. Its origin is subject to the influence of several factors that have different functions and dynamics. Geological, geomorphological, pedological, phytogeographic, hydroclimatic and anthropogenic agents trigger and condition phenomena, implying a change in structure, speed and duration. According to Garcia's classification (2012), this work aims to identify the conditioning and triggering agents of rockfalls, in the Riacho Trapiá watershed, located on the southern of Serra da Meruoca, northwestern Ceará. The methodological steps were: bibliographical and cartographic survey, geoprocessing techniques, field research and data collection. It is understood that the different factors that lead to the occurrence of rockfalls can be grouped in two sets, being they conditioners, which lead to the predisposition to the beginning of falls, and the triggers, which are dynamic and directly start the morphodynamic processes. Therefore, the present analysis can serve as the basis for several types of studies on geomorphological topics, such as slope dynamics analysis, risk mapping, environmental planning, or watershed management.Keywords: Morphodynamic; Geomorphological Susceptibility; Rockfalls. RESUMENLas caídas de rocas son procesos naturales, clasificados como eventos geomorfológicos peligrosos para el hombre por los impactos que pueden tener en las poblaciones que viven en laderas susceptibles. Su brote está sujeto a la influencia de varios factores que tienen diferentes funciones y dinámicas. Los agentes geológicos, geomorfológicos, pedológicos, fitogeográficos, hidroclimáticos y antrópicos desencadenan y condicionan los fenómenos, lo que implica un cambio en su estructura, velocidad y duración. De acuerdo con la clasificación de García (2012), este artículo objetiva identificar el acondicionamiento y los agentes desencadenantes de las caídas en la cuenca del Riacho Trapiá, ubicada en la ladera sur de la Serra da Meruoca, al noroeste de Ceará. Los pasos metodológicos fueron: levantamiento bibliográfico y cartográfico, técnicas de geoprocesamiento, investigación de campo e integración de datos. Se entiende que los diferentes factores que conducen a la aparición de caídas se pueden agrupar en dos conjuntos, que son factores condicionantes, guiando la predisposición         a la aparición de caídas, y los factores desencadenantes, que son dinámicos e inician directamente procesos morfodinámicos. Este análisis puede servir como base para estudios sobre temas geomorfológicos, tales como análisis de dinámica de taludes, mapeo de riesgos, planificación ambiental o gestión de cuencas hidrográficas.Palavras clave: Morfodinámica; Susceptibilidad Geomorfológica; Caídas de Rocas.

Measuring the Engineering-Relevant Aspects of Non-Synoptic Wind Hazards

2020 ◽  
Author(s):  
John L. Schroeder
Keyword(s):  
Remote Sensing ◽  
High Resolution ◽  
Atmospheric Science ◽  
Wind System ◽  
Engineering Community ◽  
Synoptic Wind ◽  
Wind Hazards ◽  
Science Community ◽  
Wind Storms ◽  
Measurement Campaigns

This article reviews the techniques and approaches historically employed to measure non-synoptic wind storms. While most of these efforts have originated from the atmospheric science community, the focus of this article relates to meeting the requirements of the engineering community. While the recognition of the importance of these non-synoptic wind system events is increasing, their engineering-relevant characteristics are still largely unknown. While gaps in knowledge concerning the engineering-relevant aspects of non-synoptic wind systems are plentiful, focused application of high-resolution research instrumentation offers hope to remove many of these unknowns. Future engineering-oriented measurement campaigns will likely make use of both traditional anemometry and remote sensing technologies to document the characteristics of non-synoptic wind systems.

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