Temperature change and macroinvertebrate biodiversity: assessments of organism vulnerability and potential distributions     

Fengqing Li  Namil Chung  Mi-Jung Bae  Yong-Su Kwon  Tae-Sung Kwon  Young-Seuk Park 《Climatic change》2013,119(2):421-434

Peninsular environments are ecosystems that are one of the most vulnerable to global warming. Despite the importance of conserving regional biodiversity, peninsular environments are among the least studied with respect to the influences of global warming. In this study, we used data on benthic macroinvertebrate communities from 521 sites across Korea (a nationwide scale) to evaluate the potential impact of temperature increases on river ecosystems. Weighted averaging regression models (WARMs) were used to project the relationships between relative macroinvertebrate abundance and water temperature, based on the temperature data of the Intergovernmental Panel on Climate Change (IPCC) A1B scenario. Maximum tolerance water temperatures were used to quantify the risks to macroinvertebrates at the catchment and national scales. Ambient air temperatures in the 2090s were projected to increase by an average of 3.4?ºC relative to the baseline of the 2000s at the national scale. Mayflies, stoneflies and caddisflies were identified as potentially the most sensitive taxa to global warming. The impact of global warming on macroinvertebrates was predicted to be minimal prior to the 2060s; however, by the 2080s, species loss was predicted to be 55 %. Potential distribution ranges of cold water species in the future decades were expected to decrease continuously over time, while those of warm species were expected to increase from the 2000s to the 2040s and then decrease until the 2080s. Our projections may be useful for understanding how climate parameters affect the biogeographical patterns of aquatic biodiversity from a thermal-preference perspective.  相似文献   

Application of generalized contaminant retardation factor to a multi‐phase system     

Song‐Bae Kim  Dong‐Ju Kim 《水文研究》2003,17(15):3059-3068

In this study, a generalized contaminant retardation factor applicable to a multiphase system where various types of colloids exist simultaneously with contaminants is derived and incorporated into an equilibrium model which is successfully applied to experimental data for which phenanthrene was used as hydrophobic organic contaminants and dissolved organic matter (DOM) or bacteria as mobile carriers. Based on the parameter values for the experimental data regarding the association of phenanthrene with solid matrix, DOM and various bacterial isolates, numerical experiments are performed to examine the transport behaviour of hydrophobic organic contaminants in various types of the multiphase system. Numerical experiments demonstrate that the extent of contaminant transport enhancement depends on the adsorption affinity of the colloid, its concentration and its mobility, and that the importance of a third phase to contaminant transport needs to be evaluated carefully with respect to the relevance of experimental conditions applied to realistic environmental conditions. Copyright © 2003 John Wiley & Sons, Ltd.  相似文献   

Numerical analysis of bacterial transport in saturated porous media     

Song‐Bae Kim 《水文研究》2006,20(5):1177-1186

A mathematical model to describe bacterial transport in saturated porous media is presented. Reversible/irreversible attachment and growth/decay terms were incorporated into the transport model. Additionally, the changes of porosity and permeability due to bacterial deposition and/or growth were accounted for in the model. The predictive model was used to fit the column experimental data from the literature, and the fitting result showed a good match with the data. Based on the parameter values determined from the literature experimental data, numerical experiments were performed to examine bacterial sorption and/or growth during bacterial transport through saturated porous media. In addition, sensitivity analysis was performed to investigate the impact of key model parameters for bacterial transport on the permeability and porosity of porous media. The model results show that the permeability and porosity of porous media could be altered due to bacterial deposition and growth on the solid matrix. However, variation of permeability due to bacterial growth was trivial compared with natural permeability variation. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   

Analysis of Cryptosporidium parvum oocyst transport in porous media     

Song‐Bae Kim  M. Yavuz Corapcioglu 《水文研究》2004,18(11):1999-2009

Cryptosporidium parvum is a protozoan parasite, transmitted through aqueous environments in the form of an oocyst. In this study, a transport model into which sorption, filtration and inactivation mechanisms are incorporated is applied to simulate laboratory column data, and the suitability of a kinetic model to describe the C. parvum oocyst transport and removal in porous media is compared with an equilibrium model. The kinetic model is applied to simulate previous column experimental data and successfully simulates the concentration peak; the late time tailing effect appeared in the breakthrough curves, indicating that the kinetic model is more suitable than the equilibrium one at simulating the fate and transport of the oocysts in porous media. Simulation illustrates that sorption causes retardation along with a tailing in the breakthrough curve. Additionally, filtration acts as a major mechanism of removing the oocysts from the aqueous phase, whereas the role of inactivation in reducing the viable oocyst concentration is minimal. Copyright © 2004 John Wiley & Sons, Ltd.  相似文献   

Quaternary glacial history of the Central Karakoram   总被引：3，自引：0，他引：3  

Yeong Bae Seong  Lewis A. Owen  Michael P. Bishop  Andrew Bush  Penny Clendon  Luke Copland  Robert Finkel  Ulrich Kamp  John F. Shroder Jr. 《Quaternary Science Reviews》2007,26(25-28):3384-3405

The Quaternary glacial history of the world's highest mountains, the Central Karakoram, is examined for the first time using geomorphic mapping of landforms and sediments, and ¹⁰Be terrestrial cosmogenic nuclide surface exposure dating of boulders on the moraines and glacially eroded surfaces. Four glacial stages are defined: the Bunthang glacial stage (>0.7 Ma); the Skardu glacial stage (marine Oxygen Isotope Stage [MIS] 6 or older); the Mungo glacial stage (MIS 2); and the Askole glacial stage (Holocene). Glaciers advanced several times during each glacial stage. These advances are not well defined for the oldest glacial stages, but during the Mungo and Askole glacial stages glacial advances likely occurred at 16, 11–13, 5 and 0.8 ka. The extent of glaciation in this region became increasingly more restricted over time. In the Braldu and Shigar valleys, glaciers advanced >150 km during the Bunthang and Skardu glacial stages, while glaciers advanced >80 km beyond their present positions during the Mungo glacial stage. In contrast, glaciers advanced a few kilometers from present ice margins during the Askole glacial stage. Glacier in this region likely respond in a complex fashion to the same forcing that causes changes in Northern Hemisphere oceans and ice sheets, teleconnected via the mid-latitude westerlies, and also to changes in monsoonal intensity.  相似文献   

Evaluation of drought and flood risks in a multipurpose dam under climate change: a case study of Chungju Dam in Korea     

Soojun Kim  Jaewon Kwak  Hui Seong Noh  Hung Soo Kim 《Natural Hazards》2014,73(3):1663-1678

The purpose of this study was to evaluate the effects of climate change on the drought and flood risks of a multipurpose dam. To achieve this, A2 climate change scenarios of RegCM3 were collected about Chungju Dam in Korea. To analyze drought risks, weather data obtained by the statistical downscaling method were entered to produce runoff series by runoff modeling and water balance was analyzed based on water use scenarios to review changes in the storage volume under climate change. To analyze flood risks, changes in water levels of the dam in future flood seasons were reviewed based on the current dam operation method. The results of the review indicated that both the drought and the flood risks of the dam would increase in the future. The reason was considered to be the movement of the flood season’s runoff characteristics from July and August to August and September because of climate change. Therefore, for climate change adaptation planning, not only quantitative changes in hydrologic values but also changes in temporal characteristics should be considered and given importance.  相似文献   

Changes in future precipitation over South Korea using a global high-resolution climate model     

Sanghun Lee  Deg-Hyo Bae  Chun-Ho Cho 《Asia-Pacific Journal of Atmospheric Sciences》2013,49(5):619-624

We used daily precipitation data from a global high-resolution climate scenario to analyze the features of future precipitation including extreme and heavy rainfall. The scenario shows that the model reproduces the daily precipitation over South Korea well. The projections show an increase in annual precipitation of approximately 18% in the late 21st century, with the highest increase (38%) occurring in winter. The number of days with daily precipitation of less than 5 mm decreases, but that of daily precipitation of more than 5 mm increases slightly in the latter part of the 21st century. The peak of precipitation days shifted from July to August. The number of days with relatively small amounts of precipitation (10 and 30 mm d^?1) increases most substantially in the winter season, but that for large amounts of precipitation (50, 80, 100, and 130 mm d^?1) increases most in the summer season. Events with heavy precipitation rates of 100 and 130 mm d^?1 are expected to occur in the winter season in the late 21st century, although no such events occurred during the winter season in the reference period.  相似文献   

Development and application of a novel miniature in situ microprofiler (NAFRI BelpI)     

Jae Seong Lee  Eun-Soo Kim  Sung-Hyun Kahng  Seok-Hyun Yoon  Jin-Hyung Cho  Kyung-Soo Bahk  Dong-Jin Kang 《Ocean Science Journal》2012,47(4):489-495

We have developed a novel miniature in situ microprofiler (NAFRI BelpI) for coastal and deep-sea studies. The BelpI can carry up to three oxygen microsensors, and it allows for simultaneous replicate measurements in a relatively small area. All functions can be controlled and programmed via a small magnetic bar and three reed switches; this feature facilitates the initial setup both onboard and underwater. The large LCD window shows basic information such as the movement intervals of the linear stage, number of replicate measurements, waiting time between measurements, and the pA from the microsensors. From high-resolution vertical profiles of oxygen in coastal sediment measured using the microsensors, the diffusivity boundary layer thicknesses was determined to be in the range 0.30–0.35 mm. In addition, the time-series measurement of oxygen profiles in permeable sandy sediment showed advective transport of oxygen into pore water by tidal agitation. Two examples of in situ measurement using a BelpI suggest that it can be widely applied to the study of the sediment-water interface.  相似文献   

Improved water quality in response to pollution control measures at Masan Bay, Korea     

Chang WK  Ryu J  Yi Y  Lee WC  Lee CW  Kang D  Lee CH  Hong S  Nam J  Khim JS 《Marine pollution bulletin》2012,64(2):427-435

The total pollution load management system (TPLMS) was first applied in 2007 to the highly developed Masan Bay watershed, Korea. To evaluate the effect of TPLMS on water quality improvement, we analyzed the water qualities in rivers and bay during 2005-2010, targeting chemical oxygen demand (COD), suspended sediment (SS), total nitrogen (TN), and total phosphorus (TP) loads. Land-based pollutant loading all decreased during this period, with a significant reduction in COD and SS loads (p<0.01). The COD reduction in seawater, following the TPLMS implementation, was also significant (p<0.01). Time-lagged responses in COD and Chl-a supported an estimated seawater residence time of ~1 month. Land-based nutrient loads were also significantly reduced for TN (p<0.01) and TP (p<0.05), however, significant reductions were not observed in the bay, indicating potential alternative nutrient inputs from non-point sources into the bay system.  相似文献   

Laplace–Fourier-Domain Waveform Inversion for Fluid–Solid Media     

Seung-Goo Kang  Ho Seuk Bae  Changsoo Shin 《Pure and Applied Geophysics》2012,169(12):2165-2179

Full waveform inversion algorithms are widely used in the construction of subsurface velocity models. In the following study, we propose a Laplace–Fourier-domain waveform inversion algorithm that uses both Laplace-domain and Fourier-domain wavefields to achieve the reconstruction of subsurface velocity models. Although research on the Laplace–Fourier-domain waveform inversion has been published recently that study is limited to fluid media. Because the geophysical targets of marine seismic exploration are usually located within solid media, waveform inversion that is approximated to acoustic media is limited to the treatment of properly identified submarine geophysical features. In this study, we propose a full waveform inversion algorithm for isotropic fluid–solid media with irregular submarine topography comparable to a real marine environment. From the fluid–solid system, we obtained P and S wave velocity models from the pressure data alone. We also suggested strategies for choosing complex frequency bands constructed of frequencies and Laplace coefficients to improve the resolution of the restored velocity structures. For verification, we applied our Laplace–Fourier-domain waveform inversion for fluid–solid media to synthetic data that were reconstructed for fluid–solid media. Through this inversion test, we successfully restored reasonable velocity structures. Furthermore, we successfully extended our algorithm to a field data set.  相似文献