Alteration of hydrologic indicators for Korean catchments under CMIP5 climate projections          下载免费PDF全文

Mun‐Ju Shin  Hyung‐Il Eum  Chung‐Soo Kim  Il‐Won Jung 《水文研究》2016,30(24):4517-4542

The change of hydrological regimes may cause impacts on human and natural system. Therefore, investigation of hydrologic alteration induced by climate change is essential for preparing timely proper adaptation to the changes. This study employed 24 climate projections from the Coupled Model Intercomparison Project Phase 5 (CMIP5) under Representative Concentration Pathway (RCP) 4.5 scenario. The climate projections were downscaled at a station‐spacing for seven Korean catchments by a statistical downscaling method that preserves a long‐term trend in climate projections. Using an ensemble of future hydrologic projections simulated by three conceptual rainfall‐runoff models (GR4J, IHACRES, and Sacramento models), we calculated Hydrologic Alteration Factors (HAFs) to investigate degrees of variations in Indicators of Hydrologic Alteration (IHAs) derived from the hydrologic projections. The results showed that the seven catchments had similar trend in terms of the HAFs for the 24 IHAs. Given that more frequent severe floods and droughts were projected over Korean catchments, sound water supply strategies are definitely required to adapt to the alteration of streamflow. A wide range of HAFs between rainfall‐runoff models for each catchment was detected by large variations in the magnitude of HAFs with the hydrologic models and the difference could be the hydrologic prediction uncertainty. There were no‐consistent tendency in the order of HAFs between the hydrologic models. In addition, we found that the alterations of hydrologic regimes by climate change are smaller as the size of catchment is larger. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   

SWAT application to estimate design runoff curve number for South Korean conditions     

Nam Won Kim  Jin Won Lee  Jeongwoo Lee  Jeong Eun Lee 《水文研究》2010,24(15):2156-2170

Runoff estimations based on the standard USDA–NRCS curve number (CN) table without calibration have a tendency to give inaccurate results when the CN values are applied in South Korea which has many high slope watersheds and that has a continental monsoon climate. Particularly for the design flood estimation, accurately calibrated CN values are required because the estimated peak flow is very sensitive to the selection of CN. However, the lack of flood data makes it difficult to calibrate and assign runoff CNs to Korean watersheds. Even if sufficient data are available to estimate CN values, it is also difficult to obtain the direct flows by separating base flows from total runoff hydrographs due to the temporal irregularity of rainfall events and the resulting complex pattern of runoff. Therefore, an alternative method for estimating CNs needs to be developed to overcome these issues. The purpose of this study is to present a method for estimating runoff CNs using the soil and water assessment tool (SWAT) model which can take into account watershed heterogeneities such as climate conditions, land use and soil types. The proposed CN estimation method uses the simulated flow data by SWAT instead of using measured flow data. This method has advantages in estimating CN values spatially for each subbasin division considering watershed characteristics. The use of daily data can reduce the sensitivity to the abnormality that is commonly involved in flow data with a small time scale. The SWAT‐based CN estimation method, combined with the asymptotic CN method, was applied to the Chungju dam watershed in South Korea. A regression equation was then developed from this approach, which was used to estimate CN values that decrease exponentially as rainfall amounts increase and that converge to 60·6 and 79·4 without and with considering subsurface lateral flow, respectively. Furthermore, the CN values for the antecedent moisture conditions were determined using the probabilistic approach. The CN associated with the 50% probability for the Chungju dam watershed is 87·8 which can be taken to be representative of antecedent moisture condition (AMC) II. The CN_I and CN_III associated with 90% and 10% probabilities are 78·9 and 94·1, respectively. The estimated CN_II = 87·8 differs markedly from the geographic information system (GIS)‐based CN 65·0, which implies that the standard USDA–NRCS CN method should be calibrated to the studied area of interest. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

Influence of rain infiltration on the stability of compacted soil slopes   总被引：1，自引：0，他引：1  

Won Taek Oh  Sai K. Vanapalli 《Computers and Geotechnics》2010

Stability analyses for a homogeneous compacted embankment were undertaken considering infiltration of water into the embankment. The analyses include several different practical scenarios: (i) saturated condition, (ii) ponding (or runoff) along with saturated condition, (iii) short term analysis for unsaturated conditions, and (iv) long term analysis for unsaturated conditions. The appropriate shear strength parameters of the compacted soil required for analyzing different practical scenarios were determined using conventional and modified triaxial shear apparatus. The results of the study show that typically shallow circular failures above water front occur due to infiltration rather than the conventional infinite slope type failures.  相似文献   

Characterization of cholinesterases in marbled sole, Limanda yokohamae, and their inhibition in vitro by the fungicide iprobenfos     

Jung JH  Addison RF  Shim WJ 《Marine environmental research》2007,63(5):471-478

Cholinesterases (ChEs) have been characterized in marbled sole (Limanda yokohamae) for use as a possible biomarker of pollution exposure. In brain, ChEs existed almost exclusively (>95%) as acetylcholinesterase (AChE) whereas in muscle, about 20-30% of ChE activity was in the form of butyrylcholinesterase (BChE; pseudocholinesterase). Acetylthiocholine and butyrylthiocholine (identified in mammalian studies as diagnostic substrates for AChE and BChE respectively) were hydrolyzed mainly, but not exclusively, by these enzymes. The inhibitors BW284C51 and iso-OMPA (identified in mammalian studies as diagnostic inhibitors of AChE and BChE respectively) were not specific for these enzymes in marbled sole. Brain AChE and muscle AChE and BChE were characterized in terms of their kinetic properties (KM etc.) and optimal conditions (substrate concentration, protein concentration, pH etc.) were established to allow routine assays of ChE activity to proceed under pseudo-first order conditions. The sensitivity of ChEs to a locally significant pesticide, iprobenfos (IBP; kitazin) was established in terms of IC50 concentrations. Brain AChE was relatively insensitive to IBP, but muscle AChE and BChE were sensitive to IBP concentrations in the high nM range. However, ambient IBP concentrations in Korean coastal waters are usually not high enough to cause detectable ChE inhibition in this species.  相似文献   

Application of nonylphenol and coprostanol to identification of industrial and fecal pollution in Korea     

Li D  Shim WJ  Dong M  Oh SH 《Marine pollution bulletin》2007,54(1):101-107

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Application of a fuzzy operator to susceptibility estimations of coal mine subsidence in Taebaek City,Korea   总被引：6，自引：3，他引：3  

Jong-Kuk Choi  Ki-Dong Kim  Saro Lee  Joong-Sun Won 《Environmental Earth Sciences》2010,59(5):1009-1022

Quantitative determination of locations vulnerable to ground subsidence at mining regions is necessary for effective prevention. In this paper, a method of constructing subsidence susceptibility maps based on fuzzy relations is proposed and tested at an abandoned underground coal mine in Korea. An advantage of fuzzy combination operators over other methods is that the operation is mathematically and logically easy to understand and its implementation to GIS software is simple and straightforward. A certainty factor analysis was used for estimating the relative weight of eight major factors influencing ground subsidence. The relative weight of each factor was then converted into a fuzzy membership value and integrated as a subsidence hazard index using fuzzy combination operators, which produced coal mine subsidence susceptibility maps. The susceptibility maps were compared with the reported ground subsidence areas, and the results showed high accuracy between our prediction and the actual subsidence. Based on the root mean square error and accuracy in terms of success rates, fuzzy γ-operator with a low γ value and fuzzy algebraic product operator, specifically, are useful for ground subsidence prediction. Comparing the results of a fuzzy γ-operator and a conventional logistic regression model, the performance of the fuzzy approach is comparative to that of a logistic regression model with improved computational. A field survey done in the area supported the method’s reliability. A combination of certainty factor analysis and fuzzy relations with a GIS is an effective method to determine locations vulnerable to coal mine subsidence.  相似文献   

Description of feeding apparatus and mechanism innemopilema nomurai kishinouye (scyphozoa: rhizostomeae)     

Hye Eun Lee  Won Duk Yoon  Donghyun Lim 《Ocean Science Journal》2008,43(1):61-65

Feeding apparatus, mechanism and passage of ingested prey were described forNemopilema nomurai (Scyphozoa: Rhizostomeae).N. nomurai medusae without central mouths have developed complicated canal systems connecting the tip of the tentacle and oral arm to the gut cavity. The number of junctions in the canal system increases with the bell diameter. The prey is gathered by paralyzing nematocyst at the tentacles and by adhering cirri at the oral arms and scapulets. They are engulfed into the terminal pore located at the oral arms and scapulets, and entered into the gut cavity via the canal system. The estimated digestion time is 1 hour and 20 min. The diameter of terminal pore is always about 1 mm, implying that they could not eat prey larger than that pore size. On the other hand, ephyrae have central mouths and could swallow prey as large as adults could. Exploitation of the same size of food by adult and ephyra implies thatN. nomurai can affect seriously the whole food web, massively ingesting micro-and mesozoopl a n k t o n and cutting the energy transfer toward the higher level of carnivores.  相似文献   

The effect of ozone and aerosols on the surface erythemal UV radiation estimated from OMI measurements     

Joonsuk Lee  Won Jun Choi  Deok Rae Kim  Seung-Yeon Kim  Chang-Keun Song  Jun Suk Hong  Youdeog Hong  Sukjo Lee 《Asia-Pacific Journal of Atmospheric Sciences》2013,49(3):271-278

Surface erythemal UV radiation is mainly affected by total column ozone, aerosols, clouds, and solar zenith angle. The effect of ozone on the surface UV radiation has been explored many times in the previous studies due to the decrease of ozone layer. In this study, we calculated the effect of aerosols on the surface UV radiation as well as that of ozone using data acquired from Ozone Monitoring Instrument (OMI). First, ozone, aerosol optical depth (AOD), and surface erythemal UVB radiation measured from satellite are compared with those from ground measurements. The results showed that the comparison for ozone was good with r ² of 0.92. For aerosol, there was difference between satellite measurements and surface measurements due to the insufficient information on aerosol in the retrieval algorithm. The r ² for surface erythemal UV radiation was high (～0.94) but satellite measurements showed about 30% larger values than surface measurements on average by not considering the effect of absorbing aerosols in the retrieval process from satellite measurements. Radiative amplification factor (RAF) is used to access the effect of ozone and aerosol quantitatively. RAF for ozone was 0.97～1.49 with solar zenith angle. To evaluate the effect of aerosol on the surface UV radiation, only clear-sky pixel data were used and solar zenith angle and total column amount of ozone were fixed. Also, RAF for aerosol was assessed according to the single scattering albedo (SSA) of aerosols. The results showed that RAF for aerosol with smaller SSA (< 0.90) was larger than that for with larger SSA (> 0.90). The RAF for aerosol was 0.09～0.22 for the given conditions which was relatively small compared to that for ozone. However, considering the fact that aerosol optical depth can change largely in time and space while the total column amount of ozone does not change very much, it needs to include the effect of aerosol to predict the variations of surface UV radiation more correctly.  相似文献   

Forearc serpentinite mélange from the Hongseong suture, South Korea   总被引：1，自引：0，他引：1  

Sung Won Kim  M. Santosh  Nari Park  Sanghoon Kwon 《Gondwana Research》2011,20(4):852-864

The signature of a prolonged subduction–accretion history from Paleozoic to Early Mesozoic is preserved within the dismembered serpentinite mélanges within the Hongseong suture. Here we present major and trace element data from the mafic fragments/blocks within the Baekdong serpentinite mélange revealing their arc-like tholeiite affinity within a suprasubduction zone tectonic setting. Chromian spinel compositions from the Baekdong hydrated mantle peridotite (serpentinite) are characterized by high Cr# (0.53–0.67) and Fe²⁺/Fe³⁺ ratio, medium Mg# (0.42–0.55), and Al₂O₃ contents (17–25 wt.%) indicating a forearc tectonic environment for the hydrated mantle peridotite. The estimated melting degree (> 17.6%) and FeO/MgO of the parental melt (0.9–1.3) are consistent with that of forearc magmas. SHRIMP zircon U–Pb ages from a high-grade mafic rock and an anorthosite from the study area give protolith ages of ~ 310 Ma and ~ 228 Ma, respectively. Zircons from an associated orthogneiss block within the mélange yield a Neoproterozoic crystallization age of ~ 748 Ma. These results, together with the recent SHRIMP zircon ages from other dismembered serpentinite mélanges within the Wolhyeonri complex, suggest that Paleozoic to Early Mesozoic subduction and subsequent collision events led to the exhumation of the hydrated forearc mantle peridotites from a metasomatized mantle wedge. The Hongseong region preserves important clues to a long-lived subduction system related to global events associated with the final amalgamation of the Pangaea supercontinent.  相似文献   

A Paleozoic subduction complex in Korea: SHRIMP zircon U–Pb ages and tectonic implications     

Sung Won Kim  Sanghoon Kwon  M. Santosh  Ian S. Williams  Keewook Yi 《Gondwana Research》2011,20(4):890-903

The Wolhyeonri complex in the southwestern margin of the Korean Peninsula is divided into three lithotectonic units: Late Paleozoic Zone I to the west, Middle Paleozoic Zone II in the middle and Early Paleozoic Zone III to the east. Zones II and III display characteristics of continental arc magmatic sequence. Zone II is dominated by mafic metavolcanics, whereas zone III is characterized by the presence of dismembered serpentinite bodies including chaotic mélange. These zones are proposed to have been formed in a convergent margin setting associated with subduction. Here we present zircon SHRIMP U–Pb ages from the various units within the Wolhyeonri complex which reveal the Paleozoic tectonic history of the region. The Late Carboniferous ages obtained from the main shear zone between the Wolhyeonri complex and the Paleoproterozoic Gyeonggi massif are thought to mark the timing of continental arc magmatism associated with the subduction process. In contrast, Zone I with Neoproterozoic arc magmatic remnants might indicate deposition in a forearc basin. The Wolhyeonri complex also preserves strong imprints of the Triassic collisional event, including the presence of Middle Triassic high-pressure metabasites and eclogites near the eastern boundary of the Zone III. These range of radiogenic ages derived from the Wolhyeonri complex correlate well with subduction and accretion history between the North and South China cratons. Similar geochronological features have also been indentified from the Qinling, Tongbai–Xinxian, and northern Dabie areas in east-central China. The existence of Paleozoic coeval subduction in East Asia prior to the Triassic collision is broadly consistent with a regional tectonic linkage to Gondwana.  相似文献