نتایج جستجو برای: Mountainous ground

تعداد نتایج: 148108  

Journal: :amirkabir international journal of electrical & electronics engineering 2015
r. khosravi s. h. sadeghi r. moini

the produced electric and magnetic fields due to lightning strikes to mountainous ground are determined in this paper. for the sake of simplicity a cone-shaped ground with finite conductivity is assumed to represent a natural nonflat ground. by this assumption, we deal with an axillary symmetrical structure so we use the cylindrical 2d-fdtd to save the simulation memory and time, dramatically. ...

2009
Yu-Chang Chan Dimitri Komatitsch Jeroen Tromp

We combine light detection and ranging (LiDAR) digital terrain model (DTM) data and an improved mesh implementation to investigate the effects of highresolution surface topography on seismic ground motion based upon the spectralelement method. In general, topography increases the amplitude of shaking at mountain tops and ridges, whereas valleys usually have reduced ground motion, as has been ob...

2009
Qi Chen

Gaussian decomposition has been used to extract terrain elevation from waveforms of the satellite lidar GLAS (Geoscience Laser Altimeter System), on board ICESat (Ice, Cloud, and land Elevation Satellite). The common assumption is that one of the extracted Gaussian peaks, especially the lowest one, corresponds to the ground. However, Gaussian decomposition is usually complicated due to the broa...

R. Khosravi R. Moini S. H. Sadeghi

The produced electric and magnetic fields due to lightning strikes to mountainous ground are determined in this paper. For the sake of simplicity a cone-shaped ground with finite conductivity is assumed to represent a natural nonflat ground. By this assumption, we deal with an axillary symmetrical structure so we use the cylindrical 2D-FDTD to save the simulation memory and time, dramatically. ...

2013
Xueling ZHU Juan ZHANG Zeng PING Jia LIU

Due to limitations of 0.618 pole method, the triangle method and the champ ground resistance tester method on grounding resistance measurement of transmission lines and towers under conditions of complex landscape in a mountainous area, it adopts a generalized three-electrode grounding resistance measurement method which arranges electrode flexibly in the grounding resistance measurement of tra...

2009
Jeroen Tromp

Topography influences ground motion and, in general, increases the amplitude of shaking at mountain tops and ridges, whereas valleys have reduced ground motions, as is observed from data recorded during and after real earthquakes and from numerical simulations. However, recent publications have focused mainly on the implications for ground motion in the mountainous regions themselves, whereas t...

Journal: :Remote Sensing 2016
Gaofei Yin Ainong Li Yelu Zeng Baodong Xu Wei Zhao Xi Nan Huaan Jin Jinhu Bian

Increasing attention is being paid on leaf area index (LAI) retrieval in mountainous areas. Mountainous areas present extreme topographic variability, and are characterized by more spatial heterogeneity and inaccessibility compared with flat terrain. It is difficult to collect representative ground-truth measurements, and the validation of LAI in mountainous areas is still problematic. A cost-c...

2013
Jun Liu Huaxing Bi Jinzhao Zhu Peilin Zhu Xinjie Wang Guohua Li

In the process of high resolution images orthorectification, an uneven distribution of ground control points in mountainous area results in the phenomenon of ground objects dislocation between orthophotos edges in the overlap area. Followed image mosaic, fusion and interpretation are seriously affected. High-resolution (2.5 m) panchromatic images with a 30% forward overlap of ALOS satellite wer...

Journal: :Nature communications 2012
Ellen Wohl Kathleen Dwire Nicholas Sutfin Lina Polvi Roberto Bazan

Published research emphasizes rapid downstream export of terrestrial carbon from mountainous headwater rivers, but little work focuses on mechanisms that create carbon storage along these rivers, or on the volume of carbon storage. Here we estimate organic carbon stored in diverse valley types of headwater rivers in Rocky Mountain National Park, CO, USA. We show that low-gradient, broad valley ...

2012
Ali Mohammadi Torkashvand Hamid Reza

This study investigates the possibility providing gully erosion map by the supervised classification of satellite images (ETM) in two mountainous and plain land types. These land types were the part of Varamin plain, Tehran province, and Roodbar subbasin, Guilan province, as plain and mountain land types, respectively. The position of 652 and 124 ground control points were recorded by GPS respe...

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