Conservation of wetlands are important because wetlands are hatcheries for fishes and habitat for migratory birds and mammals. Wetlands also function as a filter for polluted water and material and transition zone for harboring numerous species of plants and animals. This paper reviewed the importance of wetland conservation and policy on management of wetlands in Korea. Wetland Conservation Act(1999) and Maritime Management Act(1999) are two legislation for conservation of wetlands. Wetland Conservation Act is issued by both Ministry of Environment and Ministry of Maritime Affairs and Fisheries. The definition of wetlands are so diverse, but this paper categorized wetlands as both natural and man-made lakes, mud flat areas and inland wetlands. Management application was considered for each wetland categories.

The fractal study in river basin has been performed for the sinuosity of an individual stream and bifurcation of the stream network. The previous studies has suggested many methods or equations for the fractal dimension estimation in a river network. This study used those many equations for the estimation of fractal dimensions on the streams such as Bokha, Gonjiam, and Pocheon streams. The estimated dimensions are in the range of 1 to 1.359 for the individual stream and 1.634 to 2 for the stream network. The most of equations were suggested based on the assumption of self-similarity of a river basin for the individual stream and stream network. However, the real river basin could be characterized by self-affinity rather than self-similarity. Even though we estimate the dimensions by using many equations, we could not recommend which one is better equation for the estimation of fractal dimension. This might be from the self-similarity assumption of equations. Therefore, the assumption and research work of self-affinity will be needed for the appropriate estimation of fractal dimension in river basin.

This study was performed to research the relation between airmass thunderstorm and stability index with 12 years meteorological data(1990~2001) at Busan. Also We used the analysed stability indices from University of Wyoming to consider airmass thunderstorm. The frequency of thunderstorm occurrence during 12 years was 156 days(annual mean 13days). The airmass thunderstorm frequency was 14 days, most of those occurrence were summertime(59%). And occurrence hour of airmass thunderstorm was distributed from 1300LST to 2100LST broadly. The highest forecast index for airmass thunderstorm at Busan was K index, the lowest forecast index was SWEAT index. The forecasting of thunderstorms is based primary on the concepts of conditional instability, convective instability, and forced lifting of air near the surface. Instability is a critical factor in severe weather development. Severe weather stability indices can be a useful tool when applied correctly to a given convective weather situation.

The flood damage reduction studies have been performed by the channel improvement plan and the levee has mainly constructed with the freeboard concept. However, the freeboard concept might be an inappropriate choice as a safety factor of the levee because many uncertainties are involved in the procedure of the channel improvement plan studies. So, we considered the uncertainties In the discharge-probability, stage-discharge, and stage-damage functions and estimate the expected annual damage. The Monte Carlo technique for uncertainty analysis is used. As our results, the expected annual damage with uncertainty shows the larger value than without uncertainty. Since the expected annual damage with uncertainty already considers the safety factor it is the proper result. However, the expected annual damage without uncertainty does not consider the safety factor yet. Thus, if the expected annual damage without uncertainty considers the freeboard concept, it could be compared with the expected annual damage with uncertainty for the evaluation of the overestimation or underestimation of the levee construction.

The subject of sediment transport has been studied for centuries by engineers and river morpohologists. Many of the complex aspects of sediment transport are yet to be understood, and remain among the challenging subject for future studies. In this study, the finite element model is applied to various hypothetical channels. On the basis of the flow analysis results, sediment transport analysis is conducted using 3-different optional equations, and the results are compared with experimental results. For the purpose of predicting the sediment movements in natural river, RMA model is applied to Geum-River. It turned out to be very effective tool to predict various aspects of river evolution and the effects of hydraulic structures. The simulation results are also linked to the Geographic Information Systems (GIS).

The unsteady 2D convection and diffusion equation is solved numerically for the real-time simulation of suspended load propagation. The streamlined upwind scheme efficiently reduces numerical oscillations due to the high Peclet number in the convection dominant flow. By using the mixed boundary condition to express the external source terms or externally induced suspended load as a function of time in the algorithm, the model is capable of handling not only continuous load cases but also non-continuous suspended load influx. The suspended load transport modelwas verified using a case study for which an analytical exact solution is available and was applied to the real-time simulation of a suspended load influx case on the Mississippi River. The model algorithm can provide a framework upon which water quality as well as contaminant transport models can be built.