Variability and Risk Analysis of Hong Kong Air Quality Based on Monsoon and El Nino Conditions     

Jong-Suk KIM  ZHOU Wen  Ho Nam CHEUNG  Chak Hang CHOW 《大气科学进展》2013,30(2):280-290

This study presents an exploratory analysis aimed at improving understanding of the variability of Hong Kong air quality associated with different climate conditions. Significantly negative correlations were found when Nino 3 led particulate matter ≤10 μm PM₁₀) and NO₂ by 2--3 months over the Hong Kong territory, while the other pollutants (e.g., O₃, SO₂) showed modest correlations. A significant decreasing trend in visibility was observed during the autumn and winter, which has potential implications for the air-quality degradation and the endangerment of human health in Hong Kong. In an El Nino summer, the visibility was relatively better, while visibility in other seasons was diminished. On the other hand, in La Nina events, significant changes occurred in visibility in winter and autumn. Air pollution indices were less sensitive to the South China Summer Monsoon (SCSM), but a relatively high correlation existed between the East Asian Winter Monsoon (EAWM) and air pollutants. Rainfall was lower during most of the strong EAWM years compared to the weak years. This result suggests that the pollutants that accumulate in Hong Kong are not easy to wash out, so concentrations remain at a higher level. Finally, based on the conditional Air Pollution Index (API) risk assessment, site-specific vulnerabilities were analyzed to facilitate the development of the air-quality warning systems in Hong Kong.  相似文献   

Valuing climate impacts in integrated assessment models: the MIT IGSM   总被引：1，自引：0，他引：1  

John Reilly  Sergey Paltsev  Ken Strzepek  Noelle E. Selin  Yongxia Cai  Kyung-Min Nam  Erwan Monier  Stephanie Dutkiewicz  Jeffery Scott  Mort Webster  Andrei Sokolov 《Climatic change》2013,117(3):561-573

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Radiative torques: analytical model and basic properties     

A. Lazarian  Thiem Hoang 《Monthly notices of the Royal Astronomical Society》2007,378(3):910-946

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Soil moisture monitoring on a steep hillside     

Sanghyun Kim  Heysun Lee  Nam C Woo  Joon Kim 《水文研究》2007,21(21):2910-2922

In this study, a soil monitoring system for a hillslope with steep relief and shallow soil depth was designed and installed to represent efficiently the spatial and temporal features of soil moisture. The study was conducted on a mountainous hillslope of the Sulmachun catchment (northeastern South Korea). The positions of soil moisture sensors were determined through a sequential procedure including intensive geomorphologic surveying of the study area, surface and subsurface terrain analysis, and inverse surveying. Using 26 sensors, soil moisture data from 11 locations were measured and recorded at hourly intervals over 380 h from 6 to 22 November 2003. Soil moisture response patterns were captured for a few consecutive rainfall events. The monitoring results are discussed in the context of soil moisture variations with terrain attributes. The immediate recharge and fast recession after a peak are the primary features of soil moisture in the upper zone. Stability and significant storage increase are distinct characteristics of soil moisture in the buffer zone and the flow path zone respectively. Spatial distribution of temporal soil moisture variations can be characterized in terms of recession, stability and recharge depending upon the topographic classification of a hillslope for this approach. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   

Predicting soil erosion hazard in Lattakia Governorate(W Syria)   总被引：1，自引：0，他引：1  

Mohammed Safwan  Khallouf Alaa  Alshiehabi Omran  Bao Pham Quoc  Thi Thuy Linh Nguyen  Nam Thai Van  Tran Anh Duong  Harsányi Endre 《国际泥沙研究》2021,36(2):207-220

The main objective of this study is to predict soil erosion in the Lattakia Governorate(WSyria)using the Water Erosion Prediction Project model(WEPP)and to compare the result with that of the RUSLE.Field survey and data collection were carried out,and 44 soil samples were analyzed.In addition,all the necessary input files were prepared for use in the WEPP model and RUSLE.Results show that more than of 80%of the locations studied experience slight to moderate erosion(less than 5 t/ha/y),whereas the rest of the locations experience severe soil erosion hazard.Moreover,the volume of runoff estimated by the WEPP model is in the range of 51e321 mm,and the R^2 between the simulated soil erosion and the predicted runoff reached 0.68.Interestingly,the R^2 between the WEPP model and RUSLE is 0.56,which indicates a good correlation between the two models.  相似文献   

Structural controls on the occurrence and morphology of karstified assemblages in northeastern Vietnam: a regional perspective     

Hai Thanh Tran  Bat Van Dang  Chi Kim Ngo  Que Dinh Hoang  Quyen Minh Nguyen 《Environmental Earth Sciences》2013,70(2):511-520

Karstified assemblages occur widely in, and distinctively shape, the geological landscape of the northeastern part of Vietnam. These carbonate rocks were deposited during three major periods of basinal evolution including: (1) Late Cambrian, (2) Early Devonian to Early Carboniferous, and (3) Carboniferous to Earliest Triassic. These sedimentary units contain primary sedimentary structures and have undergone numerous post-depositional geological processes including multiple deformational events, which can be regionally correlated. Several thrusting events and associated folding have led to significant thickening of the carbonate units. The subsequent post-thrusting cross-folding events, followed by several phases of brittle faulting and fracturing further modified the spatial geometry and outcrop of these rocks. The combination and interaction of the primary structures with those formed during the long-lived and complicated deformational history is an important controlling factor in local and regional hydrogeological systems in the region. The geological structures now recorded in the carbonate units ultimately govern the formation of the unique modern surface and sub-surface geomorphology of the karstic terrains in northeastern Vietnam. These structures should be further investigated in the context of water resource assessment and natural hazard prediction and mitigation.  相似文献   

Release characteristics of molasses from a well-type barrier system in groundwater: a large test tank study for nitrate removal   总被引：1，自引：1，他引：0  

Byung Sun Lee  Eungyu Park  Jae Yeon Um  Kyuyeon Lee  Jina Jeong  Kyoungphile Nam 《Environmental Earth Sciences》2013,70(1):167-174

A pilot-scale study was conducted to characterize the performance of molasses' release from a well-type barrier system harboring solidifying molasses named slowly released molasses (SRM) as a reactive medium to promote indigenous denitrifying activity. A SRM rod was made by mixing molasses with paraffin wax, cellulose, and silica sands in a cylindrical mold. Two SRM systems harboring 30 and 60 SRM rods, referred to as Systems A and B, respectively, were constructed in a large flow tank (L × W × D = 8 m × 4 m × 2 m) filled with natural sands. These two systems continuously delivered molasses with groundwater flow over 96 days, with decreasing molasses' concentrations ranging from 763 to 95 and 1,150 to 183 mg L^?1 as chemical oxygen demand values (COD) for Systems A and B, respectively. From simulation results with an aid of the upscaled mass transfer function (MTF) model, the molasses' mass flux was slowly decreased with time, exhibiting 57, 11, and 3 mg COD day^?1 in 10, 100, and 365 days in System A, and 138, 25, and 6 mg COD day^?1 in System B, respectively; 90, 70, and 50 % of total molasses' mass remained after 12, 63, and 267 days in System A and 12, 65, and 291 days in System B, respectively. This study demonstrates that SRM system can provide a remedial alternative for long-term in situ treatment of nitrate-contaminated groundwater.  相似文献   

Integrative assessment of sediment quality in terms of chemical contamination in Jinhae Bay,South Korea     

Sang Hee Hong  Gi Myung Han  Un Hyuk Yim  Dhong-il Lim  Sung Yong Ha  Nam Sook Kim  Won Joon Shim 《Ocean Science Journal》2014,49(3):265-278

The assessment of sediment quality by considering chemical contaminants is required for the effective management of coastal environments. In this study, complex data sets of heavy metals and organic pollutants were integrated to evaluate sediment quality. Thirty-two target pollutants were quantitatively determined in surface sediments from 80 stations in Jinhae Bay, South Korea. A sediment quality index (SQI) was derived by combining the functions of “scope” (the number of variables that do not meet guideline objectives) and “amplitude” (the magnitude by which these variables exceed the guideline objective). The SQI reflects the spatial gradient and differences in the contamination status with regard to heavy metals and organic pollutants in Jinhae Bay. Fifty-nine out of eighty stations surveyed (74%) were classified as being in “excellent” or “good” condition according to the SQI, and no stations were in a “poor” condition. The mean sediment quality guideline quotient (mSGQq) ranged from 0.06 to 0.31 (from nontoxic to marginally toxic). Acute sediment toxicity leading to amphipod mortality was recorded at 17 stations (21%) of the 80 surveyed, where the mortality rate was slightly over 20%. No significant relationship was observed between sediment toxicity and the concentration of each toxicant or mSQGq.  相似文献   

Migration pattern of Yellow-throated buntings revealed by isotope-based geographic assignment     

Chang-Yong Choi  Hyun-Young Nam  Jong-Gil Park  Gi-Chang Bing 《International journal of geographical information science》2020,34(3):504-519

ABSTRACT

Migratory birds have evolved diverse migration strategies in response to a variety of factors, but information about the detailed migration patterns of Asian songbirds is not yet available. To understand the short-distance migration pattern of declining Yellow-throated Buntings (Emberiza elegans) in East Asia, we analyzed stable isotopes from the outermost tail feathers (rectrices) of individual buntings collected in Korea and Japan. Temporal changes in feather hydrogen (δ²H_f) and oxygen (δ¹⁸O_f) isotopic values at stopover islands suggested that northern populations start migration earlier than southern populations, especially in autumn. Latitudinal gradient in δ²H_f values of three wintering populations implied that northern breeders wintered farther north than southern breeders. The migration pattern of this bunting, known as Type II chain migration, was also inferred from hydrogen isotope-based geographic assignments of feather growth origins. Our data demonstrate that stable isotope analysis may help to bridge current knowledge gaps in songbird migration despite coarsely mapped isoscapes and as-of-yet undetermined isotope calibration functions in Asia.  相似文献   

Effects of Antimicrobial Air Filters on the Viability and Culturability of Airborne Bacteria          下载免费PDF全文

Gi Byoung Hwang  Bo Mi Kwon  Seung Jae Lee  Byung Uk Lee  Kyoung Mi Sim  Gwi‐Nam Bae  Jae Hee Jung 《洁净——土壤、空气、水》2016,44(10):1268-1277

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