• Proceedings of the Korean Society of Life Science Conference
• /
• 2003.05a
• /
• pp.148-148
• /
• 2003

• Journal of Environmental Science International
• /
• v.20 no.11
• /
• pp.1457-1464
• /
• 2011

In this study, the method of estimating hydrologic information (water depth, submerged period etc.) on the proper selection of construction point and scale as well as vegetation type suggested for the design of natural riparian rehabilitation structure. Long-term comprehensive watershed model SWAT-K(Korea) was applied to this purpose. Flow duration analysis was conducted to analyze the hydrologic characteristics of Pyungchang watershed at which the 'bangtul' construction method was tested. For this purpose 20 years (1989-2008) rainfall runoff analysis was carried out. Based on the simulated daily streamflow data, flow duration curve was made to analyze the flow characteristics, and the water depth hydrograph was made to analyze the water depth distribution at the cross section. Finally, the information for the selection of proper vegetation according to the submerged period is suggested.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2003.05b
• /
• pp.871-874
• /
• 2003

• Proceedings of the Korea Water Resources Association Conference
• /
• 2005.09b
• /
• pp.1338-1339
• /
• 2005

• Proceedings of the Korea Water Resources Association Conference
• /
• 1987.07a
• /
• pp.75-75
• /
• 1987

• Proceedings of the Korea Water Resources Association Conference
• /
• 2008.05a
• /
• pp.629-633
• /
• 2008

Frequently occurring flood and drought have increased the necessity of an effective water resources control and management of river flows. Therefore, the simulation of the flow distribution in natural rivers is very important to the solution of a wide variety of practical flow problems in water resources engineering. Usually in many flow problems, two-dimensional approach can provide good estimates of complex flow features in the flow around islands and obstructions, flow at confluence and flow in braided channel. The objective of this study is to examine validation of developed an accurate and robust two-dimensional finite element method with wet and dry simulation in complex natural rivers. Milyang river, and Kumho river and Keum river were performed for tests. The results were compared with those of existing model. The suggested model displayed reasonable flow distribution compared with existing model in dry area for application of natural river flow. As a result of this study, the developed general two-dimensional model provide a reliable results for flow distribution of wet and dry domain, it could be further developed to basis for extending to water quality and sediment transport analysis.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.44 no.2
• /
• pp.129-133
• /
• 1999

Excessive soil water at vegetative growth stages during the rainy season induces yield losses in soybeans. Our objectives were to obtain basic information about the cultivar differences and to understand the stress-tolerance process for due to excessive soil water. Previous experiments revealed soybean genotypic differences in tolerance to excessive soil water. A field experiment was conducted at the Research Farm of Korea University near Seoul on 21 May 1998. Soybean[Glycine max (L.) Merrill] cultivars, 'Hannamkong' (sensitive) and 'Taekwan-gkong'(tolerant) were planted in vinyl-lined plots(1.2 x 4.2 x 0.3 m deep) and control plots. Drip irrigation began at VI growth stage to submerge the soil surface. Three weeks of excessive soil water treatment reduced all growth parameters measured to soybean plants. Excessive soil water stress resulted in decreases of N, P, K, Ca, Mg and Cu, and increases of Fe and Mn contents in soybean leaves. The stress index of tolerant cultivars under excessive soil water showed no large difference in soybean growth characteristics measured at three growth stages. However, K, Ca, Mg, Fe and Mn contents in soybean leaves appeared to differ between sensitive and tolerant cultivars. From the above results, stress and tolerance indices are proposed for a method to test cultivar differences in plant responses within a species under adverse growth environments.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.29 no.2
• /
• pp.22-31
• /
• 2001

The purpose of this paper is to investigate in resources of natural recreation forest(RNRF) developed both publicly and privately in order to answer the research question: what are the differences in RNRF development between public and private developers. After reviewing the literature, the developer´s decision-making and motivation of investment, and the planning process of natural recreation forest, We constructed the conceptual framework and have formulated the hypothesis of this research. We had obtained data through a questionnaire, which surveyed of 625 visitors at 9 of the 72 natural recreation forests in Korea in 1999, We have analyzed the data using the mean difference test and logistic regression method. We found that 1) the overall quality of resource elements in RNRF has been development excellent except for the sociocultural element of recreational resources, and public recreation forest have been of higher quality than that fo private development, 20 in bivariate analysis, all the variables on quality of RNRF by public developers have turned out to be better than those of private ones, 3) in multivariate analysis, such variable as valley and water, forest and wildness area, wild life, and landscape have been statistically significant at one percent level, 4) the higher the value of valley and water, the higher the probability of public development, while the higher the value of other variables excluding water and valley, the more likelihood the recreational forest is developed by a private developer, and 5) forest and wildness area has been turned out to be the most important independent variable in contributing to the value of dependent variable. The research results suggest that 1) the differences in the quality of resource elements in RNRF developed by public and private body be considered in the planning and design process in order to develop diverse activities to make use of the resource potential, and 2) considering the resource characteristics of private natural recreation forest and the motivation of private developers, private natural recreation forest will possibly be more dynamic and dynamic attractive areas. It is recommended that the difference in the degree of visitor´s satisfaction between public and private development be examined.

• Journal of Korea Water Resources Association
• /
• v.38 no.5 s.154
• /
• pp.333-343
• /
• 2005

The upwind model is well known to simulate shockwaves, but it is rarely applied to natural rivers because of problems caused by the source terms. Although several methods have been developed to deal with the source terms, none of them has been applied to natural rivers. This paper deals with application of the upwind model to the natural river. An implicit upwind model is applied to a hypothetical irregular channel and a natural river with highly irregular bed, width, and hydraulic structures. Different types of the flows including steady-state flow, flood wave, dam-break wave, and bore are simulated to test accuracy and applicability of the implicit upwind model. It is proved that the model can simulate various types of flows in natural rivers with high accuracy and robustness.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2006.05a
• /
• pp.12-17
• /
• 2006

Natural rivers have water purification functions called Gravel Contact Oxidation Process, which decontaminate river water by biological absorption, oxidation and degradation on riverbed gravels. This function has been developed and applied to many small/medium-sized urban rivers in Japan as one of the direct river water purification methods. However the method hasn't been verified in the tropics, which have different climate conditions and river characteristics. A preliminary experiment carried out at a polluted urban tributary in the outskirts of Kuala Lumpur, Malaysia where an increasing attention has been paid to river environment, showed a good applicability to the tropical conditions as a technically practical water purification measure with some maintenance cares for sludge management.