Solute dynamics across the stream‐to‐riparian continuum under different flood waves     

Dongsheng Liu  Jian Zhao  Woo‐Hyun Jeon  Jin‐Yong Lee 《水文研究》2019,33(20):2627-2641

To enhance the understanding of solute dynamics within the stream‐to‐riparian continuum during flood event‐driven water fluctuation (i.e., flood wave), a variable saturated groundwater flow and solute transport model were developed and calibrated against in situ measurements of the Inbuk stream, Korea, where seasonal flooding prevails. The solute dynamics were further investigated for flood waves (varying by amplitude [A], duration [T], roundness [r], and skewness [t_p]) that were parameterised by real‐time stream stage fluctuations. We found that the solute transferred faster and farther in the riparian zone, especially within the phreatic zone, above which in the variable saturated zone the concentration required a significantly longer time, particularly at higher altitudes, to return to the initial state. By comparison, solute transferred shallowly in the streambed where the solute plume exhibited an exponential growth trend from the centre to the bank. The dynamic changes of solute flux and mass along the stream–aquifer interface and stream concentration were linked to the shape of flood wave. As the flood wave became higher (A↗), wider (T↗), rounder (r↘), and less skewed (t_p↗), the maximum solute storage in aquifer increased. Maximum stream concentration (C_str?max) not only presented a positive linear relationship with A or t_p but also showed a negative logarithmic trend with increasing T or r. The sensitivity of C_{str_max} to A was approximately two times that of t_p, and between these values, the r was slightly more sensitive than T. C_str?max linearly increased as hydraulic conductivity increased and logarithmically increased as longitudinal dispersivity increased. The former relationship was more sensitive than the latter.  相似文献   

The Interactive Effects of Elevated CO<Subscript>2</Subscript> and Ammonium Enrichment on the Physiological Performances of <Emphasis Type="Italic">Saccharina japonica</Emphasis> (Laminariales,Phaeophyta)     

Jin Woo Kang  Ik Kyo Chung 《Ocean Science Journal》2018,53(3):487-497

Environmental challenges such as ocean acidification and eutrophication influence the physiology of kelp species. We investigated their interactive effects on Saccharina japonica (Laminariales, Phaeophyta) under two pH conditions [Low, 7.50; High (control), 8.10] and three NH ₄ ⁺ concentrations (Low, 4; Medium, 60; High, 120 μM). The degree of variation of pH values in the culture medium and inhibition rate of photosynthetic oxygen evolution by acetazolamide were affected by pH treatments. Relative growth rates, carbon, nitrogen, and the C:N ratio in tissue samples were influenced by higher concentrations of NH ₄ ⁺ . Rates of photosynthetic oxygen evolution were enhanced under elevated CO₂ or NH ₄ ⁺ conditions, independently, but these two factors did not show an interactive effect. However, rates of NH ₄ ⁺ uptake were influenced by the interactive effect of increased CO₂ under elevated NH ₄ ⁺ treatment. Although ocean acidification and eutrophication states had an impact on physiological performance, chlorophyll fluorescence was not affected by those conditions. Our results indicated that the physiological reactions by this alga were influenced to some extent by a rise in the levels of CO₂ and NH ₄ ⁺ . Therefore, we expect that the biomass accumulation of S. japonica may well increase under future scenarios of ocean acidification and eutrophication.  相似文献   

Spatial Landslide Hazard Prediction Using Rainfall Probability and a Logistic Regression Model     

Saro Lee  Joong-Sun Won  Seong Woo Jeon  Inhye Park  Moung Jin Lee 《Mathematical Geosciences》2015,47(5):565-589

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Meteorological responses to Mt. Baekdu volcanic eruption over east asia in an offline global climate-chemistry model: A pilot study     

Byung-Kwon Moon  Daeok Youn  Rokjin J. Park  Sang-Wook Yeh  Won-Mo Kim  Young-Ho Kim  Jaein I. Jeong  Jung-Hun Woo  Eul Gyu Im  Chang-Keun Song 《Asia-Pacific Journal of Atmospheric Sciences》2011,47(4):345-351

We examine the meteorological responses due to the probable eruption of Mt. Baekdu using an off-line Climate-Chemistry model that is composed of the National Center for Atmospheric Research (NCAR) Climate Atmosphere Model version 3 (CAM3) and a global chemistry transport model (GEOS-Chem). Using the aerosol dataset from the GEOS-Chem driven by GEOS-5 meteorology, experiment and control simulations of the climate model are performed and their meteorological differences between the two simulations are analyzed. The magnitudes of volcanic eruption and column injection height were presumably set to 1/200 of the Mt. Pinatubo eruption and 9 km, respectively. Significant temperature drop in the lower troposphere (850 hPa), which is mainly due to a direct effect of prescribed volcanic aerosols from Mt. Baekdu, has been simulated up to about ?4 K. The upper atmosphere (150 hPa) right above the volcano, however, shows significant warming due to the absorption of the infrared radiation by volcanic aerosols. As a result of the volcanic eruption in the climate model, wave-like patterns are shown in both the geopotential height and horizontal wind. The changes in the lower atmospheric temperature are well associated with the modification of the atmospheric circulation through the hydrostatic balance. In spite of limitations in our current simulations due to several underlying assumptions, our results could give a clue to understanding the meteorological impacts from Mt. Baekdu eruptions that are currently attracting considerable public attention.  相似文献   

Efficiency of the modal shift and environmental policy on the Korean railroad   总被引：1，自引：1，他引：0  

Hyoung-Gi Kim  Chang-Yeoul Choi  Jung-Wouk Woo  Yongrok Choi  Kyonghwan Kim  Desheng Dash Wu 《Stochastic Environmental Research and Risk Assessment (SERRA)》2011,25(3):305-322

The Kyoto Protocol calls for industrialized nations to cut greenhouse gas emissions by 5% from 1990 levels by 2008–2012, so developed countries are presenting various policies to reduce greenhouse gas that is produced in transport fields. One of those polices is a modal shift that changes from road freight to sea, inland waterways and railroad transportation that is eco-friendly. The increase of road freight brings road congestion, accidents, logistic costs, air pollution and greenhouse gases. Railroads are superior to the other modes of transportation in mass transportability, high speed, timeliness, safety and environmental-friendliness, but the railway industry has been pushed behind in competition. Korean railroads were used by passengers and for freight transport popularly until the middle of the 20th century. However, because of the sudden change of logistics environments, having time efficiency being most important, railroads lost logistic competitive power against the transportation by truck. This paper intends to examine the modal shift to railroad transportation, which enjoys high interest as environmentally-friendly logistics, i.e., the modal shift strategy. Efficiency analysis is conducted using DEA and exploratory factors are identified for the modal shift of the companies. This paper also proposes an alternative plan for green logistics and environmentally-friendly logistics, by analyzing the characteristics of the railroad cargo transportation system and the conditions of local railroad cargo transportation.  相似文献   

Preface: Hydrogeology of cold regions     

Larry D. Hinzman  Georgia Destouni  Ming-ko Woo 《Hydrogeology Journal》2013,21(1):1-4

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Biomarker responses in caged rockfish (Sebastes schlegeli) from Masan Bay and Haegeumgang, South Korea     

Jee-Hyun Jung  So-Jueng Kim  Taek-Kyun Lee  Won Joon Shim  Seonock Woo  Dae-Jung Kim  Chang-Hee Han 《Marine pollution bulletin》2008,57(6-12):599

The purpose of this study was to compare enzymatic biomarker activities in fish caged at two sites, Masan Bay (contaminated) and Haeguemgang (reference). In the present study, ethoxyresorufin O-deethylase (EROD), brain acetyl cholinesterase (bAChE), muscle acetyl cholinesterase (mAChE) and butyryl cholinesterase (mBChE) in caged rockfish (Sebastes schlegeli) were measured 0, 1, 3, 7, 14, 21 and 30 days after caging. The level of CYP1A mRNA and Protein expression was induced higher in Masan Bay at 1, 3, 7, 14 and 30 days after caging. EROD activity in the caged fish was significantly higher in Masan Bay than in Haeguemgang 3 and 7 days after caging, but not at 14 and 30 days after caging. bAChE activity was significantly inhibited at 7 and 14 days after caging in Masan Bay. However, mBChE activity was not significantly inhibited during the experiment. Taken together, the data suggest that the caged fish were exposed, at least transiently, to CYP1A inducers and ChE inhibitors, which is consistent with our previous observations.  相似文献   

Occurrence and distribution of vibrios in fishes and shellfishes in coastal waters of Hong Kong   总被引：1，自引：0，他引：1  

Xu Huaishu  Li Jun  Phyllis Brayton  Norman Y. S. Woo  David Swartz  Zhang Shuting  Rita R. Colwell 《海洋学报(英文版)》1998,17(4):545-553

INTRODUCTIONTheoccurrenceanddistributionofhalophilicvibriosinthecoastalwatersofHongKonghasbeenrePorted(Chanetal.,l986).Theresultsshowedthatvibrioswerepresentduringthesum-mermonthsinHongKongcoastalwatersatconcentrationsof9oto67ooind./cm3,accountingo.4l%~4o%ofthetotalbacterialPOpulationofthe48isolatesexaminedindetail.Theyob-servedV.Paraheamolyticus,V.harvha,V.vulnfficus,V.camPbelliandV.fiuvialis.Becausemanyofthevibri0species,includingsome0ftheisolatesbyChanetal.(1986)fromHongKongwate…  相似文献   

Degradation of crude oil in a contaminated tidal flat area and the resilience of bacterial community     

Jaejin Lee  Il Han  Bo Ram Kang  Seong Heon Kim  Woo Jun Sul  Tae Kwon Lee 《Marine pollution bulletin》2017,114(1):296-301

Crude oil spills, Hebei Spirit in South Korea, is considered as one of the worst environmental disasters of the region. Our understanding on activation of oil-degrading bacteria and resilience of microbial community in oil contaminated sites are limited due to scarcity of such event. In the present study, tidal flat sediment contaminated by the oil spill were investigated for duration of 13 months to identify temporal change in microbial community and functional genes responsible for PAH-degradation. The results showed predominance of previously known oil-degrading genera, such as Cycloclasticus, Alcanivorax, and Thalassolituus, displaying significant increase within first four months of the accident. The disturbance caused by the oil spill altered the microbial community and its functional structures, but they were almost restored to the original state after 13 months. Present study demonstrated high detoxification capacity of indigenous bacterial populations in the tidal flat sediments and its resilience of microbial community.  相似文献   

Seismic area zones: myth or reality?     

Gordon Woo 《地学学报》1994,6(5):535-536

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