Choong-Sung Yi

Multi-Dimensional Flood Damage Analysis (I): Principle and Procedure

최근 이상홍수로 인한 인명과 재산피해가 급격히 증가하여 홍수피해를 경감시키기 위한 치수사업의 필요성은 인식하고 있으나, 사업타당성을 정확하고 객관적으로 분석할 수 있는 경제성분석 방법이 미진한 실정이다. 본 연구는 기존의 치수경제성분석을 개선하기 위한 것으로 현행 국내에서 사용중인 치수경제성분석의 문제점을 파악하고 외국의 사례와 비교 분석하여 개선방향을 도출하고 이를 바탕으로 다차원 홍수피해산정방법(MD-FDA Multi-Dimensional Flood damage analysis)을 개발하였다 주된 내용은 예상피해지역의 자산조사를 통하여

Framework for Optimum Scale Determination for Small Hydropower Development Using Economic Analysis

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Location Analysis for Developing Small Hydropower Using Geo-Spatial Information System

피해규모를 산정하고, 침수심 조건에 따라 피해율을 적용하여 예상 홍수피해액을 계산하는 것이다. 여기에서, GIS와 연계하여 침수면적뿐만 아니라 침수심의 공간적 분포를 고려하여 피해액을 보다 정확하게 산정할 수 없다. 본 연구에서 개발한 다차원 흥수피해산정방법은 기존 방법에서 야기되었던 문제점을 개선하고 계속해서 업데이트되는 국가통계자료를 이용함으로써 보다 합리적이고 정확한 피해액을 산정할 수 있으리라 사료된다. 【Recently, the flood damages including losses of human lifes and property have been rapidly increased according to extreme floods. And we know that the flood control project is needed for diminishing flood damages. However, we have had the lacks in a reasonable methodology for the economic analysis of food control project. This study aims to improve the existing economic analysis method for flood control project. So, first of all, we understand the problems of existing economic analysis and investigate the methodologies of foreign countries. Based on that, the Multi-Dimensional Flood Damage Analysis(MD-FDA) is developed in this study. The survey of properties on the floodplain is conducted, then the damage rate obtained by evaluating the monetary values of surveyed property is applied, and the expected flood damage is calculated. Also by considering damage area in the floodplain as well as spatial distribution of inundated depth using GIS, the flood damages are evaluated more accurately than existing method. From the study, we know that the MD-FDA can improve the problems of existing method and evaluate the reasonable flood damages by using updated nation리 statistics.】

Multi-Dimensional Flood Damage Analysis (II): Application

This study presents a framework for optimum scale determination for small hydropower development in a river basin. The framework includes the construction of hydrology and topography data, the simulation of hydropower operation, the economic analysis, and the determination of optimum scale of the small hydropower. The optimum scale of design flow and facility are determined by Net Present Value among economic analysis indices. The investment cost is estimated by the cost function derived from the construction cost of existing small hydropower plants. The benefit from power generation is estimated by the price announced by government. The presented framework is applied to the two potential sites in Cho River basin for the dam and run-of-river type of plants. Finally, the sensitivity analysis for a design flow and scale of the plant is performed for the each site. The usage of the framework presented in the study is highly expected for the estimation of potential hydropower resources or the decision support tool for a proprietor by estimating the optimum scale and economical feasibility in advance.

Cost-Effective Analysis for Evaluating Utility of River Levee in Policy Aspects

Small hydropower is the one of the cleanest one among new and renewable energy with less green house gas emissions. Recently, the necessity of developing small hydropower is emerging since its remaining potential resources in this country are abundant. However, a survey or research on the small hydropower development has been hardly performed since the 1990s. These circumstances encourages a systematic approach for the small hydropower development. The purpose of this study is to propose a methodology of the location analysis for developing small hydropower. To this end, constraint and location criteria with weights are established and quantification method of each factor is presented. Especially, the analysis procedure is established on the basis of GSIS. Also the study focus on raising the objectivity and precision of analysis by developing system model with automatic search. The proposed methodology is applied to Bochung stream in Keum Riverbasin. The result selects the four and two locations of dam type and run-of-river type respectively. This study will be beneficial to the future activation of small hydropower development as a fundamental work.

Alternatives Development for Basin-wide Flood Mitigation Planning by Determining Economic Optimal Project Size

This study is that MD-FDA and the existing method were applied together the outlet project under the construction in the Gulpo River basin. The results of both of them mot the economic feasibility of the Project. But, MD-FDA evaluated the suitable damage according to situations; 1) without project, 2) after 20m outlet construction, 3) after 80m outlet construction. That is, MD-FDA could exactly evaluate the Annual Expected Flood Damage by considering the characteristics to the inundated area. If M-FDA may use in the flood control projects, the projects will be able to be taken into account all characteristics of the total damage area and performed by reasonable criteria.

Site location analysis for small hydropower using geo-spatial information system

The study performs the economic analysis to evaluate the efficiency of buyout land project comparing to the conventional levee project. The cost of buying the potential flood prone area which is identified according to the designated design flood and is compared to the cost of the corresponding levee project. The main stream of Nakdong river between Hwang river and Nam river confluence was chosen as a case study area because those area are prone to the 200 year flood and the land is mostly inexpensive crop field. As a conclusion we proposed that the buyout land project is more efficient than the levee project in an economic viewpoint. Although the study analyzed under certain circumstances and focused on the economic efficiency, it is necessary our object of decision making has to be shifted to the flood prone area not on the river itself.

Water Allocation by Estimation of Damage Function in a Water-Deficit Situation

The integrated basin-wide flood mitigation planning has a numerous individual proposals with different characteristics. So, it makes difficult to develop the optimal alternative that combines such elements. To develop the optimal alternative, it`s necessary not only to assess the flood damage but also to define a tolerable degree of damage. Such a definition is made in a way, dubbed the `social consensus` in a broad sense; but initially, it requires the analysis of the economic efficiency within a scope, which is technically achievable. This study aims to propose the alternatives development method so that the combination of the individual proposals could be economically efficient. To this end, this study defined the flood mitigation projects as the economic production activities carried out by inputs and outputs, and proposed the optimal project size as the principle of developing alternatives. This study may have the worth in improving the alternatives development method by considering the optimal project scale from the economic viewpoint while the existing method depending on engineering aspect. Such approach is expected to correspond to the current government`s policy that avoids the passive flood mitigation focused on channel-wide planning but pursues the basin-wide flood mitigation planning focusing on damaged area, thereby provide efficient tools to come up with the solution.