The impacts of climate change on local hydrology and low flow frequency in the Geum River Basin,Korea     

Jae H. Ryu  Joo Heon Lee  Sangman Jeong  Seon K. Park  Kyuha Han 《水文研究》2011,25(22):3437-3447

The climate sensitive analysis of potential climate change on streamflow has been conducted using a hydrologic model to identify hydrologic variability associated with climate scenarios as a function of perturbed climatic variables (e.g. carbon dioxide, temperature, and precipitation). The interannual variation of water resources availability as well as low flow frequency driven by monsoonal time shifts have been investigated to evaluate the likelihood of droughts in a changing climate. The results show that the timing shift of the monsoon window associated with future climate scenarios clearly affect annual water yield change of ? 12 and ? 8% corresponding to 1‐month earlier and 1‐month later monsoon windows, respectively. Also, a more severe low flow condition has been predicted at 0·03 m³/s as opposed to the historic 7Q10 flow of 1·54 m³/s given at extreme climate scenarios. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

Quantitative decomposition of radiative and non-radiative contributions to temperature anomalies related to siberian high variability     

Park  Tae-Won  Jeong  Jee-Hoon  Deng  Yi  Zhou  Renjun  Cai  Ming 《Climate Dynamics》2015,45(5-6):1207-1217

Climate Dynamics - In this study, we carried out an attribution analysis that quantitatively assessed relative contributions to the observed temperature anomalies associated with strong and weak...  相似文献   

Water quality assessment at Jinhae Bay and Gwangyang Bay,South Korea     

Dongseon Kim  Seung Ho Baek  Dong-Young Yoon  Kyung-Hee Kim  Jin-Hyun Jeong  Pung-Guk Jang  Young-Ok Kim 《Ocean Science Journal》2014,49(3):251-264

A new water quality index for evaluating the water quality of Jinhae Bay and Gwangyang Bay was developed. Four water quality parameters were selected as water quality indicators for the water quality index: dissolved inorganic nitrogen (DIN), dissolved inorganic phosphorus (DIP), chlorophyll-a (Chl-a), and dissolved oxygen (DO). Reference levels of DIN, DIP, and Chl-a were determined as 6.22 μmol L^?1, 0.38 μmol L^?1, and 2.32 μmol L^?1, respectively, on the basis of a long-term dataset that was collected monthly in the Korea Strait over a period of seven years (2006–2012). The water quality index established for Jinhae Bay and Gwangyang Bay is (bottom DO grade × 0.33) + (surface Chl-a grade × 0.33) + (surface DIN grade × 0.17) + (surface DIP grade × 0.17). On the basis of a three-year observation, the water quality of Jinhae Bay was classified as “good” in winter and spring, “poor” in summer, and “fair” in autumn and exhibited large spatial variation, with the lowest-quality water observed in Masan Bay. The water quality of Gwangyang Bay was classified as “good” in winter, “fair” in spring, “poor” in summer, and “fair” in autumn. Unlike Jinhae Bay, the water quality of Gwangyang Bay exhibited minimal spatial variation. In both bays, water quality among the four seasons was worse during summer. It is essential that a survey for water quality evaluation be conducted during summer.  相似文献   

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   

Geotectonic framework of Permo–Triassic magmatism within the Korean Peninsula     

Sung Won Kim  Sanghoon Kwon  Hee Jae Koh  Keewook Yi  Youn-Joong Jeong  M. Santosh 《Gondwana Research》2011,20(4):865-889

This study presents sensitive high-resolution ion microprobe (SHRIMP) U–Pb zircon ages, and whole-rock chemical and isotopic (Sr-Nd) compositions of representative Triassic plutons from South Korea. The plutons from the Gyeonggi massif (Hongseong, Namyang, Yangpyeong and Odesan), the central Okcheon belt (Baeknok and Yongsan), and the Yeongnam massif (Sangju, Gimcheon, Hamyang and Macheon) yield zircon U–Pb ages of ca. 232–226 Ma, 227–226 Ma, and 240–228 Ma, respectively. Among the Triassic plutonic suite in South Korea, those within the Gyeonggi massif are dominated by granite, syenite, monzonite, monzodiorite and gabbro. Plutons within the Okcheon belt are mainly by granite to quartz monzodiorite. The Yeongnam massif mainly incorporates granite to granodiorite and minor monzodiorite intrusions. The geochemical signatures of the Triassic plutons are characterized by Ta–Nb troughs, depletion of P and Ti, and enrichment of LILE. Most plutons except Macheon monzodioritic pluton show high initial ⁸⁷Sr/⁸⁶Sr ratios (0.708248–0.714678) and strongly negative ε_Nd(T) (− 20.3 to − 7.7) values, suggesting contribution from middle to upper crust. In contrast, the Macheon monzodioritic pluton in the Yeongnam massif shows relatively low initial ⁸⁷Sr/⁸⁶Sr ratios (0.706547-0.706629) and negative ε_Nd(T) (− 4.43 to − 3.62) values. The Middle Triassic syenite–monzonite–granite–gabbro series in and around the Gyeonggi massif possess high-K calc-alkaline and shoshonitic affinity suggesting a post-collisional magmatic event following the Permo–Triassic collision between the North and South China blocks. The Triassic plutons in the Yeongnam massif and the Okcheon belt, together with a Permian Yeongdeok pluton in the Gyeongsang basin, show features typical of high- to medium-K calc-alkaline magmatism with LREE and LILE enrichments. This together with a depletion of Y and HREE suggests their formation in a subduction setting. Our results provide robust evidence to consider the Gyeonggi massif as an extension of the Qinling–Dabie–Sulu belt between the North and South China blocks in central China. The Okcheon belt and Yeongnam massif in South Korea, together with the continental margin of South China, are marked by a common Permian to Triassic magmatic episode, probably related to the paleo-Pacific slab subduction.  相似文献   

Seismically induced changes in groundwater levels and temperatures following the ML5.8 (ML5.1) Gyeongju earthquake in South Korea     

Lee  Soo-Hyoung  Lee  Jae Min  Moon  Sang-Ho  Ha  Kyoochul  Kim  Yongcheol  Jeong  Dan Bi  Kim  Yongje 《Hydrogeology Journal》2021,29(4):1679-1689

Hydrogeological responses to earthquakes such as changes in groundwater level, temperature, and chemistry, have been observed for several decades. This study examines behavior associated with M_L 5.8 and M_L 5.1 earthquakes that occurred on 12 September 2016 near Gyeongju, a city located on the southeast coast of the Korean peninsula. The M_L 5.8 event stands as the largest recorded earthquake in South Korea since the advent of modern recording systems. There was considerable damage associated with the earthquakes and many aftershocks. Records from monitoring wells located about 135 km west of the epicenter displayed various patterns of change in both water level and temperature. There were transient-type, step-like-type (up and down), and persistent-type (rise and fall) changes in water levels. The water temperature changes were of transient, shift-change, and tendency-change types. Transient changes in the groundwater level and temperature were particularly well developed in monitoring wells installed along a major boundary fault that bisected the study area. These changes were interpreted as representing an aquifer system deformed by seismic waves. The various patterns in groundwater level and temperature, therefore, suggested that seismic waves impacted the fractured units through the reactivation of fractures, joints, and microcracks, which resulted from a pulse in fluid pressure. This study points to the value of long-term monitoring efforts, which in this case were able to provide detailed information needed to manage the groundwater resources in areas potentially affected by further earthquakes.

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Non-parametric simulations-based conditional stochastic predictions of geologic heterogeneities and leakage potentials for hypothetical CO2 sequestration sites     

Weon Shik Han  Kue-Young Kim  Sungwook Choung  Jina Jeong  Na-Hyun Jung  Eungyu Park 《Environmental Earth Sciences》2014,71(6):2739-2752

The present study focuses on understanding the leakage potentials of the stored supercritical CO₂ plume through caprocks generated in geostatistically created heterogeneous media. For this purpose, two hypothetical cases with different geostatistical features were developed, and two conditional geostatistical simulation models (i.e., sequential indicator simulation or SISIM and generalized coupled Markov chain or GCMC) were applied for the stochastic characterizations of the heterogeneities. Then, predictive CO₂ plume migration simulations based on stochastic realizations were performed and summarized. In the geostatistical simulations, the results from the GCMC model showed better performance than those of the SISIM model for the strongly non-stationary case, while SISIM models showed reasonable performance for the weakly non-stationary case in terms of low-permeability lenses characterization. In the subsequent predictive simulations of CO₂ plume migration, the observations in the geostatistical simulations were confirmed and the GCMC-based predictions showed underestimations in CO₂ leakage in the stationary case, while the SISIM-based predictions showed considerable overestimations in the non-stationary case. The overall results suggest that: (1) proper characterization of low-permeability layering is significantly important in the prediction of CO₂ plume behavior, especially for the leakage potential of CO₂ and (2) appropriate geostatistical techniques must be selectively employed considering the degree of stationarity of the targeting fields to minimize the uncertainties in the predictions.  相似文献   

The comparison of two severe Hwangsa (Asian dust) cases of spring and winter in Seoul, Korea     

Haeyoung Lee  Jeong Eun Kim  Youngsin Chun 《Asia-Pacific Journal of Atmospheric Sciences》2013,49(1):49-56

This study investigated meteorological, physical, and chemical characteristics of 2 severe Hwangsa (Asian dust, maximum average of PM₁₀ above 1000 μg m^?3) observed in Seoul, the capital city of Korea, during 30～31^st May, 2008 (DSS2008) and 25～26^th December, 2009 (DSS2009). DSS2008 and DSS2009 had a same source region and route. However, they have different meteorological conditions. DSS2009 had a shorter travel time from the source region to Korea and shorter duration time in Korea than DSS2008 due to a strong winter Siberian anticyclone. One of DSS2008 sample was affected by not only Asian dust but also a long-range transported haze due to consecutive influx after low pressure passed while DSS2009 sample collected only dust aerosol. For both cases, the mass concentration of coarse particles (PM_10-1) increased by 3～14 times compared to that during non Asian dust period, however, that of fine particles (PM₁) increased only in DSS2008. For DSS2008 water-soluble ion balance between anions and cations in fine mode was close to 1:1 while cations were higher than anions in coarse mode. NH₄ ⁺ and Ca²⁺ were found to be the main contributing factors for the neutralization. Cl^? loss was observed about 60% indicating an active interaction of Na⁺ with pollutants. Reconstruction of chemical compositions showed relatively high concentrations of secondary pollutants (NH₄NO₃ and (NH₄)₂SO₄), CaCO₃, and Ca(NO₃)₂ compared to that during non Asian dust period. DSS2009 exhibited the typical characteristics of Asian dust having a high concentration of Ca²⁺ with higher equivalent concentration of cations than anions in all size bins. Cl^? loss was hardly observed. The secondary pollutants were lower than that of non Asian dust cases. The result of reconstruction of ionic components indicated the CaCO₃ derived from soil particle, CaSO₄, and Ca (NO₃)₂ were dominant in DSS2009.  相似文献   

Effect of anisotropic conductivity on suction and reliability index of unsaturated slope exposed to uniform antecedent rainfall     

Khalid Mahmood  Jeong Ho Ryu  Jin Man Kim 《Landslides》2013,10(1):15-22

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A study on carbon dioxide emissions from bituminous coal in Korea     

Jeongwoo Lee  Chang-Sang Cho  Ki-hyup Hong  Jae-Hak Jeong  Seungjin Kim  Eui-Chan Jeon 《Environmental Earth Sciences》2013,70(4):1709-1715

Consumption of primary energy in Korea increased 5.25 % per year over a 10 years span starting in 1990. Korea ranked 8th in primary energy consumption in 2011; coal consumption increased 35 % from 87,827 million tons in 2006–119,321 tons in 2010. Heavy energy-consuming countries consistently conduct research to develop an emission factor of Tier 2 level, reflecting the characteristics of the fuel that they use. To calculate the emission factor of bituminous coal for fuel, this study developed emission factor and calculated emission amount by implementing fuel analysis on bituminous coal consumed in Korea between 2007 and 2009. CO₂ emission factor calculated by fuel analysis method is 95,315 kg/TJ, which is 0.75 % higher than the default value suggested by IPCC. The emission amount calculated by using the CO₂ emission factor in this study is 231.881 million tons, which has a difference of 1.739 million tons compared to the IPCC default value.  相似文献