기존의 Markov Chain 모형으로 일강우량 모의시에 강우의 발생여부를 모의하고 강우일의 강우량은 Monte Carlo 시뮬레이션을 통해 일강우 분포 특성에 맞는 분포형에서 랜덤으로 강우량을 추정하는 것이 일반적이다. 이때 강우 지속기간에 따른 강도 및 강우의 시간별 분포 등의 강우 사상의 특성을 반영할 수 없다는 한계가 있다. 본 연구에서는 이를 개선하기 위해 강우 사상을 1일 지속강우, 2일 지속강우, 3일 지속강우, 4일이상 지속강우로 구분하여 강우의 지속기간에 따라 강우량을 추정하였다. 즉 강우 사상의 강우 지속일별로 총강우량의 분포형을 비매개변수 추정이 가능한 핵 밀도추정(Kernel Density Estimation, KDE)를 적용하여 각각 추정하였고, 강우가 지속될 경우에 지속일별로 해당하는 분포형에서 강우량을 구하였다. 각 강우사상에 대해 추정된 총 강우량은 k-최근접 이웃 알고리즘(k-Nearest Neighbor algorithm, KNN)을 통해 관측 강우자료에서 가장 유사한 강우량을 가지는 강우사상의 강우량 일분포 형태에 따라 각 일강우량으로 분배하였다. 본 연구는 기존의 강우량 추정 방법의 한계점을 개선하 고자 하였으며, 연구 결과는 미래 강우에 대한 예측에도 활용될 수 있으며 수자원 설계에 있어서 기초자료로 활용될 수 있을 것으로 기대된다.

The Science and Technology process focuses on a number of areas where science and technology development provides a major opportunity to innovate water resources management. A number of areas have been carefully selected and are described below. Main focus 1: Efficient water management Today’s water management continues to be highly inefficient in many respects, seriously hampering the sustainable management of water resources, delivery of services and the protection of human health and the environment. In the years to come, major efforts will need to be made to improve water efficiency as a means to secure water resources, adapt to climate change, or operate water services systems at lower costs. Sub Focus: Urban water efficiency, Agricultural water efficiency, Industrial water efficiency, Energy efficiency in water and waste water systems Main focus 2: Resource recovery from water and waste-water systems Increasingly, water and waste-water systems are recognized as potential sources of recovering water, energy, nutrients and other materials. At the same time, the re-use of waste water in agricultural, industrial and urban applications is gaining momentum. The development of re-use and recycling within the water and waste-water sectors provides major opportunities for improving environmental performance, creating climate benefits and reducing costs. Sub Focus: Water re-use and recycling technologies, Energy recovery and production from water and waste water cycles, Nutrients recovery from waste water Main focus 3: Water and Natural disasters As the devastating impact of recent natural disasters such as the flood occurred in Thailand in 2011, indicates, mankind is vulnerable to extreme weather events in developing and even in developed countries. Clearly, such extreme events have always been part of our life and may be caused by climate change. This makes water related problems, especially, such as floods and droughts, more difficult to analyze and predict. Climate change is predicted to have a range of serious consequences, some of which will have impact over the longer term, like droughts, while some have immediate and obvious impacts, such as intense rain and flooding. Floods and droughts are major natural disasters involving loss of life and the destruction of property. So, we may need advanced technologies and measures in order to cope with natural disasters. Sub Focus: Climate change : impact assessment and adaptation, Drought analysis and management, Urban floods and damage reduction studies, RS and GIS applications for natural hazards Main focus 4: Smart technology for Water Water management is increasingly influenced by developments in Smart Technology(ST). Better use of this ST in measuring, monitoring and distributing water can lead to a significant contribution in overcoming water management challenges in the 21st century. Bridging the ‘divide’ between the water and ST sectors will be important in the development and (wide-scale) application of new smart technologies in the water sector. Sub Focus: Urban and Irrigation water management and ST, Integrated and intelligent river basin water management and ST, Design and implementation of smart water grid, Water resources management and Big Data Main focus 5: Understanding and managing ecosystem services for water Ecosystems provide valuable services underpinning water security and the sustainable management of water resources. In recent years, major advances have been made in understanding the role of ecosystems in, for example, reducing floods, recharging aquifers, or protecting and improving water quality. Sub Focus: The science and technology of natural and green infrastructure management, The economic valuation of ecosystem services for water, The payment for ecosystem services for water quality and delivery

Climate change is not the only issue yet there are the combinations of many existing factors. Urbanization is one of them and is considering the major criteria. Due to the Rapid Urbanization, land use of the existing watershed is becoming impervious layer and even drainage network system is more complicated. Existing system might not be able to handle the amount of water during the storm events thus, hydrologic impact assessment is necessary for a planned development area in designing detention storage for urban drainage systems to minimize the effect of urbanization. It is advisable to reassess the existing structure to handle and to prevent the threat of flood in the future. For such assessment, single or two hydrologic models can be paired for pre- and post- development conditions. Typical pairings are the use of synthetic hydrograph methods for both conditions or synthetic hydrograph for pre-development and urban hydrology model for post-development condition. This study is aiming to assess the flood impact and suggest the proper technique for future flood prevention. To accomplish, the SWMM was adopted to development areas in Korea. The comparison of results can be done to show the new approach can resolve the irrationalities that can occur with the combination of two different models such as smaller peak flow and longer time to peak for post-development conditions. It is thought that the proposed method will improves the accountability of the flood impact assessment on future development areas

Curve number (CN), originally developed, compiled by ‘The Natural Resources Conservation Service (NRCS)’, and has been widely used throughout the world. However, there is the uncertainty of CN derived from the use of antecedent moisture condition (AMC)/Antecedent Runoff Condition (ARC). As in Korea where nearly 70% covered by mountainous area, it is still not sufficient handbook precedent to guide or support the estimation of AMC/ARC. The failure to develop formal criteria of applying AMC/ ARC will be a gaping profession and results not only in uncertainty of CN estimation in particular, but also in designing appropriate structures in Korea as a whole. This paper is aiming at presenting a critical review of AMC/ARC and deriving a procedure to deal more realistically with event rainfall-runoff over wider variety of initial conditions. Proposed methods have been developed. It is based on modifying estimated runoff to observed runoff with coefficient of determination and then applying different algebraic expression with the verification of AMC by antecedent rainfall table of NEH-1964. Clearly indicated from 12 years period analysis and 2 years period of verification, normalized root mean square error, RE and E are best described by the application of algebraic expression by Arnold et al. at the value of 0.8950, 0.9460, and 0.0244 respectively for AMC condition and 1.3799, 0.9642 and -0.0197 respectively for ARC condition. Therefore, Arnold et al. algebraic equation is the best representation criteria of AMC and ARC. This algebraic expression might be applied properly considering South Korea condition.