Effects of Topographic Slopes on Hydrological Proecsses and Climate     

Jinliang Liu  Han-Ru Cho 《大气科学进展》2001,18(5):733-741

Based on previous research results on river re-distribution models, a modification on the effects of topographic slopes for a runoff parameterization was proposed and implemented to the NCAR＇s land sur face model (LSM). This modification has two aspects: firstly, the topographic slopes cause outflows from higher topography and inflows into the lower topography points; secondly, topographic slopes also cause decrease of infiltration at higher topography and increases of infiltration at lower topography. Then changes in infiltration result in changes in soil moisture, surface fluxes and then in surface temperature, and eventual ly in the upper atmosphere and the climate. This mechanism is very clearly demonstrated in the point bud gets analysis at the Andes Mountains vicinities. Analysis from a regional scale perspective in the Mackenzie GEWEX Study (MAGS) area, the focus of the ongoing Canadian GEWEX program, shows that the modi fied runoff parameterization does bring significant changes in the regional surface climate. More important ly, detailed analysis from a global perspective shows many encouraging improvements introduced by the modified LSM over the original model in simulating basic atmospheric climate properties such as thermodynamic features (temperature and humidity). All of these improvements in the atmospheric climate simulation illustrate that the inclusion of topographic effects in the LSM can force the AGCM to produce a more realistic model climate.  相似文献   

INFLUENCES OF TOPOGRAPHY ON BAROCLINIC SOLITARY ROSSBY WAVES IN A MULTILEVEL MODEL          下载免费PDF全文

L&#; Keli  H. R. Cho 《Acta Meteorologica Sinica》1992,6(3):311-324

The KdV equation with topography included in an N-level model is derived. It is shown that if the topography ex-ists. the KdV equation may describe the solitary Rossby waves in the case of basic current without vertical shear, and itis no necessary to introduce the MKdV equation. The results of calculations show that the change of horizontal shearpattern of basic flow may cause an important change of the streamline pattern of the solitary waves with the oddmeridional wavenumber m, and has no effect for the even meridional wavenumber m. The vertical shear increases thesteepness of the barotropic solitary modes, and it has a complicated effect on the baroclinic modes. The influences oftopographic slope on the solitary waves are very great. The southern and northern slopes of topography may cause dif-ferent solitary wave patterns, with the effect of northern slope greater. The effect of Froude number on the solitarywaves is generally to steepen the solitary waves, however, the effect also depends on the meridional wavenumber m andthe modes of solitary wave.  相似文献   

Rock Cutting Depth Model Based on Kinetic Energy of Abrasive Waterjet     

Tae-Min Oh  Gye-Chun Cho 《Rock Mechanics and Rock Engineering》2016,49(3):1059-1072

  相似文献   

Observation of the Degradation Characteristics and Scale of Unevenness on Three-dimensional Artificial Rock Joint Surfaces Subjected to Shear     

Eun-Soo Hong  Tae-Hyuk Kwon  Ki-Il Song  Gye-Chun Cho 《Rock Mechanics and Rock Engineering》2016,49(1):3-17

The present study explores the degradation characteristics and scale of unevenness (small-scale roughness) on sheared rock joint surfaces at a low-stress regime. While the degradation characteristics of unevenness and the normal stress are mutually interrelated, an understanding of the degradation patterns of the three-dimensional roughness of rock joints is one of the important components needed to identify asperity failure characteristics and to quantify the role of damaged unevenness in establishing a shear strength model. A series of direct shear tests was performed on three-dimensional artificial rock joint surfaces at different normal stress levels. After shearing, the spatial distributions and statistical parameters of degraded roughness were analysed for the different normal stress levels. The length and area of the degraded zones showed bell-shaped distributions in a logarithmic scale, and the dominant scale (or the most frequently occurring scale) of the damaged asperities (i.e., unevenness) ranged from approximately, 0.5 to 5.0 mm in length and 0.1–10 mm² in area. This scale of the damaged unevenness was consistent regardless of the level of normal stress. It was also found that the relative area of damaged unevenness on a given joint area, and thus the contribution of the mechanical asperity failure component to shear strength increased as normal stress increased.  相似文献   

Tsunami research in Korea     

Choi  Byung-Ho  Cho  Yong-Sik  Yoon  Sung Bum 《Natural Hazards》2016,84(2):437-454

The tsunamis that have occurred in many places around the world over the past decades have taken a heavy toll on human lives and property. The eastern coast of the Korean Peninsula is not safe from tsunamis and has sustained tsunami damage in the past. The aim of this study is to review the past, present, and future of some aspects of tsunami research in Korea. A composite numerical model comprising propagation and inundation models is described. The paper also covers tsunami mitigation efforts in Korea, and a tsunami hazard map is developed and introduced.  相似文献   

Metagenomic characterization of viral communities in Goseong Bay,Korea     

Jinik Hwang  So Yun Park  Mirye Park  Sukchan Lee  Yeonhwa Jo  Won Kyong Cho  Taek-Kyun Lee 《Ocean Science Journal》2016,51(4):599-612

In this study, seawater samples were collected from Goseong Bay, Korea in March 2014 and viral populations were examined by metagenomics assembly. Enrichment of marine viral particles using FeCl₃ followed by next-generation sequencing produced numerous sequences. De novo assembly and BLAST search showed that most of the obtained contigs were unknown sequences and only 0.74% of sequences were associated with known viruses. As a result, 138 viruses, including bacteriophages (87%), viruses infecting algae and others (13%) were identified. The identified 138 viruses were divided into 11 orders, 14 families, 34 genera, and 133 species. The dominant viruses were Pelagibacter phage HTVC010P and Roseobacter phage SIO1. The viruses infecting algae, including the Ostreococcus species, accounted for 9.4% of total identified viruses. In addition, we identified pathogenic herpes viruses infecting fishes and giant viruses infecting parasitic acanthamoeba species. This is a comprehensive study to reveal the viral populations in the Goseong Bay using metagenomics. The information associated with the marine viral community in Goseong Bay, Korea will be useful for comparative analysis in other marine viral communities.  相似文献   

A framework for identifying spatiotemporal hot spots of speculative land transactions using prospective monitoring procedures: the case of South Korea     

Sunghwan Cho  Daejong Kim 《制图学和地理信息科学》2016,43(3):223-232

Abnormally high-priced transactions in urban land speculation bring detrimental effects on economy, environment, and society. Governmental agencies around the world are striving hard to monitor and control land speculation by introducing various policy objectives and tools for an efficient urban development planning. One of the major challenges in controlling land speculation is to quickly identify the spatiotemporal locations of concern (hot spots) by monitoring the spatial clustering pattern changes over time and to alert the appropriate decision-making agencies for timely policy intervention. In this paper, we introduce a framework to rapidly detect the spatiotemporal hot spots of speculative land transactions in near-real-time data by exploiting the prospective monitoring procedures. We applied this method in the city of Hwasung, Republic of Korea, as an empirical illustration and found that the locations Jeongnam, Bongdam, Mado, and Dongtan were identified as hot spots with high, concentrated transaction values. The results indicate that the proposed framework is a capable tool for capturing prospective temporal indicators and pinpointing the localities of land speculation.  相似文献   

Hydroelastic response of a very large floating structure over a variable bottom topography   总被引：1，自引：0，他引：1  

Jo Hyun Kyoung  Sa Young Hong  Byoung Wan Kim  Seok Kyu Cho 《Ocean Engineering》2005,32(17-18):2040-2052

An influence of sea-bottom topography on the hydroelastic response of a Very Large Floating Structure (VLFS) is considered. When the floating structure is constructed near the shore, the sea-bottom topographical effect should be considered. In this study, the effect of sea-bottom topography is investigated for four different bottom cases. To calculate the sea-bottom effects rigorously, the finite-element method based on the variational formulation is used in the fluid domain. The pontoon-type floating structure is modeled as the Kirchhoff plate. The mode superposition method is adopted for the hydroelastic behavior of the floating structure.  相似文献   

Marine protected areas: a tool for integrated coastal management in Belize     

Leandra Cho 《Ocean & Coastal Management》2005,48(11-12):932

Management of the Belize Barrier Reef was originally envisioned through the creation of marine protected areas. However, the influence of land-based activities was not accounted for in Marine Protected Area (MPA) programs. Therefore focus was shifted to an integrated approach via Integrated Coastal Management (ICM). The Belize ICM process has evolved into a system of coordination through the fostering of multi-sectoral linkages for integrated management of coastal resources. Marine protected areas were included in the ICM program as tools for achieving biodiversity protection and management of sensitive habitats. The ICM process has resulted in greater coordination and consultation in decision making for coastal resource issues, the MPA program however has not evolved with the trend of greater community involvement in MPA management. The greatest challenges to MPA and ICM programs in the next 10 years are: improved linkages between the two, fostering of community participation in management, broadening of the scope of ICM to watersheds and ocean governance, and sustainable financing for both programs.  相似文献   

The evolution and resolution of conflicts on Saemangeum Reclamation Project     

Dong-Oh Cho   《Ocean & Coastal Management》2007,50(11-12):930-944

The Saemanguem Reclamation Project proposed building a 33 km dike, to reclaim 28,300 ha of wetlands and estuary for rice production. In addition, the project would store 530 million tons of freshwater in the estuary for agriculture. The time frame for this construction was 21 years from 1991 to 2011 with a budget of US $2.1 billion. During the project, another reclamation project, called the “Shiwha Reclamation Project,” which was established between 1987 and 1994, was written off as a failure and an environmental disaster. The public started to recognize the value of wetlands and coastal waters and has strongly opposed the Saemanguem Reclamation Project. However, the voices of supporters for the project were also strong, so its resolution was controversial. This article analyzes the evolution and solution of conflicts among stakeholders and discusses some lessons applicable to large reclamation projects.  相似文献