Hydrologic impact of regional climate change for the snow‐fed and glacier‐fed river basins in the Republic of Tajikistan: statistical downscaling of global climate model projections     

S. Kure  S. Jang  N. Ohara  M. L. Kavvas  Z. Q. Chen 《水文研究》2013,27(26):4071-4090

Climate change due to global warming is a public concern in Central Asia. Because of specific orography and climate conditions, the republic of Tajikistan is considered as the main glacial center of Central Asia. In this study, regional climate change impacts in the two large basins of Tajikistan, Pyanj and Vaksh River basins located in the upstream sector of the Amu Darya River basin are analysed. A statistical regression method with model output statistics corrections using the ground observation data, Willmott archived dataset and GSMaP satellite driven dataset, was developed and applied to the basins to downscale the Global Climate Model Projections at a 0.1‐degree grid and to assess the regional climate change impacts at subbasin scale. It was found that snow and glacier melting are of fundamental importance for the state of the future water resources and flooding at the target basins since the air temperature had a clearly increasing trend toward the future. It was also found that the snowfall will decrease, but the rainfall will increase because of the gradual increase in the air temperature. Such changes may result in an increase in flash floods during the winter and the early spring, and in significant changes in the hydrological regime during a year in the future. Furthermore, the risks of floods in the target basins may be slightly increasing because of the increase in the frequencies and magnitudes of high daily precipitation and the increase in the rapid snowmelt with high air temperatures toward the future. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

A probabilistic model for real‐time flood warning based on deterministic flood inundation mapping     

Jiun‐Huei Jang  Pao‐Shan Yu  Sen‐Hai Yeh  Jin‐Cheng Fu  Chen‐Jia Huang 《水文研究》2012,26(7):1079-1089

Deterministic flood inundation mapping is valuable for the investigation of detailed flood depth and extent. However, when these data are used for real‐time flood warning, uncertainty arises while encountering the difficulties of timely response, message interpretation and performance evaluation that makes statistical analysis necessary. By incorporating deterministic flood inundation map outputs statistically by means of logistic regression, this paper presents a probabilistic real‐time flood warning model determining region‐based flood probability directly from rainfall, being efficient in computation, clear in message, and valid in physical meaning. The calibration and validation of the probabilistic model show a satisfactory overall correctness rate, with the hit rate far surpassing the false alarm rate in issuing flood warning for historical events. Further analyses show that the probabilistic model is effective in evaluating the level of uncertainty lying within flood warning which can be reduced by several techniques proposed in order to improve warning performance. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

The Global/Regional Integrated Model system (GRIMs)   总被引：5，自引：0，他引：5  

Song-You Hong  Hoon Park  Hyeong-Bin Cheong  Jung-Eun Esther Kim  Myung-Seo Koo  Jihyeon Jang  Suryun Ham  Seung-On Hwang  Byoung-Kwon Park  Eun-Chul Chang  Haiqin Li 《Asia-Pacific Journal of Atmospheric Sciences》2013,49(2):219-243

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Very large subaqueous sand dunes on the upper continental slope in the South China Sea generated by episodic,shoaling deep-water internal solitary waves     

D. Benjamin Reeder  Barry B. Ma  Yiing Jang Yang 《Marine Geology》2011,279(1-4):12-18

Very large subaqueous sand dunes were discovered on the upper continental slope of the northern South China Sea. The dunes were observed along a single 40 km long transect southeast of 21.93°N, 117.53°E on the upper continental slope in water depths of 160 m to 600 m. The sand dunes are composed of fine to medium sand, with amplitudes exceeding 16 m and crest-to-crest wavelengths exceeding 350 m. The dunes' apparent formation mechanism is the world's largest observed internal solitary waves which generate from tidal forcing on the Luzon Ridge on the east side of the South China Sea, propagate west across the deep basin with amplitudes regularly exceeding 100 m, and dissipate extremely large amounts of energy via turbulent interaction with the continental slope, suspending and redistributing the bottom sediment. While subaqueous dunes are found in many locations throughout the world's oceans and coastal zones, these particular dunes appear to be unique for two principal reasons: their location on the upper continental slope (away from the influence of shallow-water tidal forcing, deep basin bottom currents and topographically-amplified canyon flows), and their distinctive formation mechanism (approximately 60 episodic, extremely energetic, large amplitude events each lunar cycle).  相似文献   

Synthetic high-resolution near-IR spectra of the Sun for planetary data reductions made from ATMOS/Spacelab-3 and Atlas-3 data     

Haingja Seo  Sungwon Hwang  Aeran Jung  Ji Hyun Kim  Joo Hyeon Kim  Kap-Sung Kim  Jinny Lee  Minhwan Jang 《Icarus》2007,192(1):287-295

We have constructed synthetic solar spectra for the 2302-4800 cm⁻¹ (2.08-4.34 μm) range, a spectral range where planetary objects mainly emit reflected sunlight, using ATMOS (Atmospheric Trace Molecule Spectroscopy)/Spacelab-3 and Atlas-3 spectra, of which resolution is 0.01 cm⁻¹. We adopted Voigt line profiles for the modeling of line shapes based on an atlas of line identifications compiled by Geller [Geller, M., 1992. Key to Identification of Solar Features. A High-Resolution Atlas of the Infrared Spectrum of the Sun and the Earth Atmosphere from Space. NASA Reference Publ. 1224, vol. III. NASA, Washington, DC, pp. 1-22], who derived solar line positions and intensities from contaminated high-resolution solar spectra obtained by ATMOS/Spacelab-3. Because the ATMOS spectra in these wavelength ranges are compromised by absorption lines of molecules existing in Earth's high-altitude atmosphere and in the compartment of the spacecraft, the direct use of these high-resolution solar spectra has been inconvenient for the data reductions of planetary spectra. We compared the synthetic solar spectra with the ATMOS spectra, and obtained satisfactory fits for the majority of the solar lines with the exception of abnormal lines, which do not fit with Voigt line profiles. From the model fits, we were able to determine Voigt line parameters for the majority of solar lines; and we made a list of the abnormal lines. We also constructed telluric-line-free solar spectra by manually eliminating telluric lines from the ATMOS spectra and filling the gaps with adjacent continua. These synthetic solar spectra will be useful to eliminate solar continua from spectra of planetary objects to extract their own intrinsic spectral features.  相似文献   

Three-dimensional spatial variability of hydraulic conductivity in the Choushui River alluvial fan, Taiwan     

C.-W. Liu  C.-S. Jang  S.-C. Chen 《Environmental Geology》2002,43(1-2):48-56

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Statistical simulations of the future 50-year statistics of cold-tongue El Niño and warm-pool El Niño     

Hanna Na  Bong-Geun Jang  Won-Moon Choi  Kwang-Yul Kim 《Asia-Pacific Journal of Atmospheric Sciences》2011,47(3):223-233

Recent extensive studies have suggested that the occurrence of warm-pool El Niño has increased since the late 1970s and will increase in future climate. Occurrence frequencies of cold-tongue and warm-pool El Niño have been investigated in the observational record (1980–2006) and in the future 50 years (2007–2056) based on 100 synthetic SST datasets with estimates of statistical confidence. In the observational record, 80% of the warm-pool El Niño occurred since 1980 over a period of 27 years; only 20% of the warm-pool El Niño occurred prior to 1980 over a period of 110 years. The 100 synthetic datasets, on average, produce 142 months of cold-tongue El Niño in 2007–2056 as opposed to an average 107 months in the same length of the observational data; this is a 20.7% increase in the occurrence of cold-tongue El Niño compared with the observational period. Warm-pool El Niño occurred for 112 months in 2007–2056 as opposed to an average occurrence of 42 months in the observational record; this is 2.5 times the occurrence frequency in the 1980–2006 period in the synthetic datasets. As a result, occurrence frequencies of cold-tongue and warm-pool El Niño in the period of 2007–2056 become quite comparable to each other in the synthetic datasets. It is expected in the next 50 years that warm-pool El Niño will be nearly as frequent as cold-tongue El Niño.  相似文献   

Interpolating Spatial Interaction Data1     

Woo Jang  Xiaobai Yao 《Transactions in GIS》2011,15(4):541-555

Spatial interpolation has been widely used to improve the spatial granularity of data, or to mediate between inconsistent zoning schemes of spatial data. Traditional areal interpolation methods translate values of source zones to those of target zones. These methods have difficulty in dealing with flow data, as each instance is associated with a pair of zones. This study develops a new concept, flow line interpolation, to fill the abovementioned gap. We also develop a first flow line interpolation method to estimate commuting flow data between spatial units in a target zoning scheme based on such data in a source zoning scheme. Three models (i.e., areal‐weighted, intelligent, and gravity‐type flow line interpolation) are presented. To test the estimation accuracy and the application potential of these models, a case study of Fulton County in Georgia is conducted. The results reveal that both the areal‐weighted and intelligent models are very promising flow line interpolation methods.  相似文献   

A study on measurement and analysis of radon-222 (uranium series) emitted to the atmosphere from construction materials (cement block, kaolin brick, and gypsum board) in living environment     

Jae-Hwan Cho  Kyung-Rae Dong  Yong-Jin Ju  Woon-Kwan Chung  Seon-Chil Kim  Jong-Woong Lee  Yong-Soon Park  Eun-Jin Choi  Ho-Sung Kim  Yeong-Cheol Heo  Hyon-Chol Jang 《Environmental Earth Sciences》2013,70(4):1515-1523

The purpose of this study was to measure, compare, and analyze the air concentration of radon that was emitted to the atmosphere from construction materials such as cement brick, tile, red clay tile, and gypsum tile. The study method was to use continuous radon monitoring equipment (RTM 1688-2) to measure concentrations of radon and thoron contained in brick, tile, red clay tile, and gypsum tile. According to the measurement results, the cement brick among the four samples showed the highest measurement value for radon, while the red clay tile showed the highest measurement value for thoron. When the radon emission concentration was estimated based on materials required for construction per unit area (3.3 m²) in an actual construction, the cement brick had the highest measurement values for radon and thoron. This study confirmed the degree of radon emission from construction materials. The purpose of this study was also to suggest a method to examine the effects of radon and reduce the dose of personal radiation exposure. It is believed that the government should be active in publicizing and managing use of construction materials that have lower levels of radon emission.  相似文献   

Quantitative forecast experiment of a heavy rainfall event over Korea in a global model: horizontal resolution versus lead time issues   总被引：1，自引：0，他引：1  

Jihyeon Jang  Song-You Hong 《Meteorology and Atmospheric Physics》2014,124(3-4):113-127

In this study, we examine the deterministic predictability of heavy rainfall over the Korean peninsula using a global model, the Global/Regional Integrated Model system, by focusing on the effects of horizontal resolution and lead time prior to the onset of the target event. The control run reproduces locally concentrated heavy rainfall over the mid-western part of the Korean peninsula on 27–29 July 2011, with a model setup of about 25 km grid spacing and 24 h in advance of the onset of heavy rainfall. We found that small-scale features are represented well at higher resolution, but without significant change in the distribution of rainfall. Increase of lead time reduces the predictability of large-scale features, accompanying a northward shift of major rainfall. At lower resolution, the accuracy of the heavy rainfall prediction decreases more rapidly as lead time increases. We concluded that the increase in predictability of heavy rainfall achieved by enhancing horizontal resolution is promising, but an additional set of experiments also indicates that efforts should be made to improve the physics packages in models.  相似文献