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41.
Predicting the rainfall-triggered landslides in a forested mountain region using TRIGRS model 总被引:3,自引:0,他引:3
Landslides are natural disasters which can pose a serious threat to human and property in many areas around the world. The
Transient Rainfall Infiltration and Grid-based Regional Slope-stability (TRIGRS) model was used to investigate the rainfall-induced
shallow landslides in a forested mountain region, Korea. Various input data for TRIGRS model include time-varying rainfall,
topographic characteristics, soil depth, material strength, and hydraulic properties. A series of calculations were conducted
in determining the slope stability over the Jangheung region in Korea during the storm occurred on August 6, 1998. The results
show that TRIGRS model captured about 64.1% of landslides that were extracted from the IKONOS2 imageries. The model demonstrated
how the factor of safety changed with time during a storm considering both the transient and spatial responses of pore water
pressure in its slope stability calculation. 相似文献
42.
Hyun-Cheol Kim Hisashi Yamaguchi Sinjae Yoo Jianrong Zhu Kazumaro Okamura Yoko Kiyomoto Katsuhisa Tanaka Sang-Woo Kim Taewook Park Im Sang Oh Joji Ishizaka 《Journal of Oceanography》2009,65(1):129-135
Sea-viewing Wide Field-of-view Sensor (SeaWiFS) chlorophyll-a distribution in summer in the East China Sea during 1998–2007 was analyzed. Statistical analysis with K-means clustering
technique allowed us to define the proper satellite chlorophyll-a concentration indicating the Changjiang Diluted Water (CDW). The spatial distributions of the higher satellite chlorophyll-a concentrations (>0.48 mg m−3) corresponded well with the distributions of lower salinity CDW (<30–32) every year. Interannual variation of the CDW area,
indicated by the high satellite chlorophyll-a, correlated with the interannual variation of the Changjiang summer freshwater discharge. The correlation analysis indicated
that the CDW spread eastward in the East China Sea with a time lag of 1 to 2 months after the discharge. 相似文献
43.
44.
Gil Young Kim Gwang Soo Lee Dong Geun Yoo Young Kyo Seo Im Hak Kim 《Marine Georesources & Geotechnology》2018,36(3):264-270
The KISAP (Korea Institute of Geoscience and Mineral Resources Seafloor Acoustic Probe) was developed to obtain in situ compressional wave velocity and attenuation profiles for seafloor sediments. The instrument comprises recording channel receivers, and an acoustic source, and can be attached to a corer or a probe. Here, we report experiments comparing KISAP in situ velocity to laboratory velocity of colocated piston cores. KISAP data matched laboratory data (corrected for temperature and pressure) reasonably. KISAP can be used to collect in situ acoustic data and can be effectively used to calibrate previous laboratory data to in situ data. 相似文献
45.
Support vector machines in remote sensing: A review 总被引:19,自引:0,他引:19
Giorgos Mountrakis Jungho Im Caesar Ogole 《ISPRS Journal of Photogrammetry and Remote Sensing》2011,66(3):247-259
A wide range of methods for analysis of airborne- and satellite-derived imagery continues to be proposed and assessed. In this paper, we review remote sensing implementations of support vector machines (SVMs), a promising machine learning methodology. This review is timely due to the exponentially increasing number of works published in recent years. SVMs are particularly appealing in the remote sensing field due to their ability to generalize well even with limited training samples, a common limitation for remote sensing applications. However, they also suffer from parameter assignment issues that can significantly affect obtained results. A summary of empirical results is provided for various applications of over one hundred published works (as of April, 2010). It is our hope that this survey will provide guidelines for future applications of SVMs and possible areas of algorithm enhancement. 相似文献
46.
Natural Hazards - This study investigates the capability of two numerical models, namely the Weather Research and Forecasting (WRF) and Cloud Resolving Storm Simulator (CReSS), to simulate the... 相似文献
47.
Comparing groundwater recharge and base flow in the Bukmoongol small-forested watershed,Korea 总被引:1,自引:0,他引:1
E. A. Combalicer S. H. Lee S. Ahn D. Y. Kim S. Im 《Journal of Earth System Science》2008,117(5):553-566
Groundwater recharge and base flow using different investigated methods are simulated in the 15-ha Bukmoongol small-forested
watershed located at the southern part of Korea. The WHAT system, PART, RORA, PULSE, BFI, and RAP software are used to estimate
groundwater recharge or base flow and base flow index from the measured streamflow. Results show that about 15–31 per cent
of annual rainfall might be contributed for base flow. The watershed groundwater recharge proportions are computed to about
10–21 per cent during the wet period and 23–32 per cent for the remainder periods. Mean annual base flow indices vary from
0.25 to 0.76 estimated using different methods. However, the study found out that all methods were significantly correlated
with each other. The similarity of various methods is expressed as a weighted relationship provided by the matrix product
from the principal component analysis. Overall, the BFI and WHAT software appeared consistent in estimating recharge or base
flow, and base flow index under Korea’s conditions. The case study recommends the application of different models to other
watersheds as well as in low-lying areas where most observation groundwater wells are located with available streamflow data. 相似文献
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49.
The effect of topography and sea surface temperature on heavy snowfall in the Yeongdong region: A case study with high resolution WRF simulation 总被引:1,自引:0,他引:1
Sun-Hee Jung Eun-Soon Im Sang-Ok Han 《Asia-Pacific Journal of Atmospheric Sciences》2012,48(3):259-273
An analysis of the heavy snowfall that occurred on 11?C14 February 2011 in the Yeongdong region along the eastern coast is presented. Relevant characteristics based on observation and model simulations are discussed with a focus on the times of maximum snowfall in Gangneung (GN) and Daegwallyong (DG). This event was considered part of the typical snowfall pattern that frequently occurs in the Yeongdong region due to the prevailing northeasterly flow. The control simulation using the high resolution Weather Research and Forecasting (WRF) model (1 km × 1 km) showed reasonable performance in capturing the spatial distribution and temporal evolution of precipitation. The area of precipitation maxima appeared to propagate from the plain coastal region further into the inland mountainous region, in relation to the location of convergence zone. In addition, a series of sensitivity experiments were performed to investigate the effect of topography and sea surface temperature (SST) on the formation of heavy snowfall. The change of topography tended to modulate the topographically induced mechanical flow, and thereby modify the precipitation distribution, which highlights the importance of an elaborate representation of the topography. On the other hand, the sensitivity experiment to prescribe positive (negative) SST forcing shows the enhanced (suppressed) precipitation amount due to the change of the sensible and latent heat fluxes. 相似文献
50.
Detecting areal changes in tidal flats after sea dike construction using Landsat-TM images 总被引:1,自引:0,他引:1
Moon Seong Kang Sang June Im Tae Il Jang Seung Woo Park Sang Min Kim 《Journal of Earth System Science》2007,116(6):561-573
The main objective of this study was to estimate changes in the area of tidal flats that occurred after sea dike construction
on the western coast of South Korea using Landsat-TM images. Applying the ISODATA method of unsupervised classification for
Landsat-TM images, the tidal flats were identified, and the resulting areas were quantified for each image. The area of tidal
flats from a topographic map published in one year differs significantly from that shown in another, which appears to be attributable
to the tide levels at the time of aerial photography. During the study period, the area of tidal flats, as estimated from
Landsat-TM images, increased by 4.57 km2 per year in the study areas. The tidal flats in the inner sea of Chunsu Harbor area increased by 200 m2 per zone, while the accumulation for a number of inner sea areas within Asan Harbor area occurred at over 50m2 per zone. The results of this research may serve as the basis of an environmentallyfriendly development plan for tidal flats. 相似文献