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101.
This paper proposes and tests a method of producing macrofauna habitat potential maps based on a weights-of-evidence model (a probabilistic approach) for the Hwangdo tidal flat, Korea. Samples of macrobenthos were collected during field work, and we considered five mollusca species for habitat mapping. A weights-of-evidence model was used to calculate the relative weights of 10 control factors that affect the macrobenthos habitat. The control factors were compiled as a spatial database from remotely sensed data combined with GIS analysis. The relative weight of each factor was integrated as a species potential index (SPI), which produced habitat potential maps. The maps were compared with the surveyed habitat locations, revealing a strong correlation between the potential maps and species locations. The combination of a GIS-based weights-of-evidence model and remote sensing techniques is an effective method in determining areas of macrobenthos habitat potential in a tidal flat setting. 相似文献
102.
Effects of the Changjiang river discharge on sea surface warming in the Yellow and East China Seas in summer 总被引:2,自引:0,他引:2
Taewook Park Chan Joo Jang Johann H. JungclausHelmuth Haak Wonsun ParkIm Sang Oh 《Continental Shelf Research》2011,31(1):15-22
This study explores the effects of the Changjiang (also called the Yangtze River) river discharge (CRD) on the density stratifications and associated sea surface temperature (SST) changes using a global ocean general circulation model with regional focus on the Yellow and East China Seas (YECS). It is found that CRD increases the SST in summer through a barrier layer (BL) formation that tends to enhance stratification at the mixed layer base, and thus reduces both vertical mixing and entrainment. This process is effective, particularly in August, after the CRD reaches its maximum in July. The SST difference between the composites of flood and drought years confirms that the surface warming is related to surface freshening by the CRD. This result suggests that the BL induced by the CRD is an important contributor to the surface heat budget in the YECS. 相似文献
103.
The impact of the risk environment and energy prices to the budget of Korean households 总被引:2,自引:2,他引:0
Hyungho Youn Byung In Lim Eui Young Lee YongRok Choi 《Stochastic Environmental Research and Risk Assessment (SERRA)》2011,25(3):323-330
Energy is closely related to environmental risk. A rising fuel price in the 1970s had hurt consumers and caused disturbance
to the natural environment. Households could not afford high imported energy prices and thus resorted to fuel wood. Land competed
for fuel wood and agricultural crops, and thus high fuel prices strained the environment with respect to the use of land.
If human health and safe housing were included in environmental risk, a high energy price would induce broader environmental
risk. Households with limited income would not be able to use expensive fossil energy to warm their houses and would depend
on only electric mats or blankets to keep warm. Such insufficient warming methods would not only threaten their health but
would also worsen the condition of their houses. The abrupt increase in energy prices in 2007 and 2008 had significantly impacted
environmental risk. It forced low income households to spend more on energy, leaving less for other expenditure segments,
but had left high income households generally intact. This contrasting effect between different income groups had increased
the sustainability of the energy risks at the high prices. This study shows how risks associated with the household economy
have increased in response to the recent dramatic increases in energy prices. We develop a method for assessing risk by using
the variance of ratios of energy expenditure to current income. We then examine how differently the economic change has increased
risk across expenditure segments. We find energy expenditure as the biggest contributor to the risk. In addition, we illustrate
how energy expenditure has changed the risk profile for each income group, with the first group (i.e., the lowest income group)
experiencing the greatest increase. This group hurts the most during days of high energy prices. 相似文献
104.
Changhwan Oh Julien Legrand Kyungsik Kim Marc Philippe In SungPaik 《Journal of Asian Earth Sciences》2011,40(3):710-721
Mesozoic fossil floras are distributed over eastern Asia (China, Mongolia, Siberia, Korea and Japan) according to a regular latitudinal pattern. Two floras are usually distinguished, a northern type and a southern type, the distribution of which oscillated during the Mesozoic. In Japan, this regular pattern is disrupted by a sharp inflexion of the boundary between the two floras. Two competing hypotheses have been proposed to explain this disruption. One hypothesis advocates later tectonic motion clouding the original pattern, while the other hypothesis proposes that a warm oceanic current allowed the southern flora to grow much further north in coastal areas. We used fossil wood, a biotic component that has not previously been used, for a palaeobiogeographical study of the region. The observed fossil wood diversity at the generic level does not fit with the hypothesis of a warm oceanic current, unless this hypothesis is modified to include alternating warm northbound and cold southbound oceanic currents. Our results provide new evidence for the palaeoecology of the Mesozoic continental biota in Far-East Asia. 相似文献
105.
Sensitivity analysis for the GIS-based mapping of the ground subsidence hazard near abandoned underground coal mines 总被引:3,自引:3,他引:0
Ground subsidence around abandoned underground coal mines can cause much loss of life and property. We analyze factors that
can affect ground subsidence around abandoned mines in Jeongahm in Kangwon-do by sensitivity analysis in geographic information
system (GIS). Spatial data for the subsidence area, topography and geology and various ground engineering data were collected
and used to make a factor raster database for a ground subsidence hazard map. To determine the importance of extracted subsidence-related
factors, frequency ratio model and sensitivity analysis were employed. Sensitivity analysis is a method for comparing the
combined effects of all factors except one. Sensitivity analysis and its verification showed that using all factors provided
91.61% accuracy. The best accuracy was achieved by not considering the groundwater depth (92.77%) and the worst by not considering
the lineament (85.42%). The results show that the distance from the lineament and the distance from the drift highly affected
the occurrence of ground subsidence, and the groundwater depth, land use and rock mass rating had the least effects. Thus,
we determined causes of ground subsidence in the study area and this information could help in the prediction of ground subsidence
in other areas. 相似文献
106.
Seok Lee Heung-Jae Lie Cheol-Ho Cho Sok Kuh Kang William J. Teague Kyung-Il Chang Kyu-Min Song Kyung-Hee Oh 《Ocean Science Journal》2011,46(2):73-84
The vertical structure of the M2 tidal current in the Yellow Sea is analyzed from data acquired using an acoustic Doppler current profiler. The observed vertical
profiles of the M2 tidal current are decomposed into two rotating components of counter-clockwise and clockwise, and restructured using a simple
one-point model with a constant vertical eddy viscosity. The analyzed results show that the internal fictional effect dominates
the vertical structure of the tidal current in the bottom boundary layer. In the Yellow Sea, the effect of the bottom friction
reduces the current speed by about 20–40% and induces the bottom phase advance by about 15–50 minutes. In the shallower coastal
regions, the effects of bottom topography are more prominent on the vertical structure of tidal currents. The vertical profile
of the tidal current in summer, when the water column is strongly stratified, is disturbed near the pycnocline layer. The
stratification significantly influences the vertical shear and distinct seasonal variation of the tidal current. 相似文献
107.
Spindel R.C. Jungyul Na Dahl P.H. Suntaek Oh Eggen C. Young Gyu Kim Akulichev V.A. Morgunov Y.N. 《Oceanic Engineering, IEEE Journal of》2003,28(2):297-302
A pilot experiment was conducted in the Sea of Japan (also called the East Sea) in September-October 1999, to assess the possibility of using acoustic tomographic techniques for monitoring water mass structure and dynamics. Acoustic m-sequence signals at various frequencies between 250 and 634 Hz were transmitted from bottom-mounted acoustic sources in shallow water off the coast of Vladivostok to vertical-array receiving systems deployed off the north coast of Ulleung-Do island (S. Korea), 558 km to the south. The data are analyzed for temporal correlation, time spread, and transmission loss and are interpreted in terms of a tomographic system for monitoring the East Sea. 相似文献
108.
109.
An observation of the corona during the 7 March, 1970 eclipse through a Wollaston prism-red and blue filter combination was carried out for the purpose of confirming the prediction that the component of the K-corona with electric vector radial to the Sun is redder than the tangential component. An analysis of a portion of the resulting data seems to confirm this prediction, and also indicates that the method is useful for determining the three-dimensional configuration of the very inner corona. A three-dimensional configuration is suggested for a portion of the NE quadrant of the Sun, including the large NE streamer and an adjacent low-lying loop. 相似文献
110.
Substructure hybrid simulation has been actively investigated and applied to evaluate the seismic performance of structural systems in recent years. The method allows simulation of structures by representing critical components with physically tested specimens and the rest of the structure with numerical models. However, the number of physical specimens is limited by available experimental equipment. Hence, the benefit of the hybrid simulation diminishes when only a few components in a large system can be realistically represented. The objective of the paper is to overcome the limitation through a novel model updating method. The model updating is carried out by applying calibrated weighting factors at each time step to the alternative numerical models, which encompasses the possible variation in the experimental specimen properties. The concept is proposed and implemented in the hybrid simulation framework, UI‐SimCor. Numerical verification is carried out using two‐DOF systems. The method is also applied to an experimental testing, which proves the concept of the proposed model updating method. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献