지구온난화에 따른 한반도 주변의 해수면 변화와 그 영향에 관한 연구 Ⅱ

Abstract

The Third Assessment Report of the Intergovernmental Panel on Climate Change (IPCC) concluded that the global warming due to the enhanced greenhouse effect since the Industrial Revolution will be accelerated in the 21st century. The projected warming will increase the steric sea level rise of ocean which have large adverse effects such as coastal lowland inundation, wetland displacement, coastal erosion, saltwater intrusion into estuaries and freshwater aquifers, altered tidal range in rivers and bays, change in tide and wave patterns, change in sedimentation on the coastal zone in which rich natural ecosystem is exhibited and active socioeconomic system has been already occurred. This study intends to assess the potential impact of the future sea level rise in the coastal zone of the Korean Peninsula. The questions we asked in the present study are as follows: Is the coastal zone of Korean Peninsula vulnerable to the 21st sea level rise? If yes, how much and where? What are appropriate strategy and system corresponding to the vulnerability of the sea level rise? What are future tasks in Korea? We focused on the socioeconomic system in the vulnerability assessment of Korean Peninsula to the sea level rise and chose inundation area and inundated people as the vulnerability index for the assessment. Fourteen sea level rise scenarios are computed with a combination of steric sea level rise, tide, and storm surge. For the 1-m sea level rise scenario with high tide and storm surge, the maximum inundation areas appear to be 2,643 km2, which is about 1.2% of total area of the Korean Peninsula. The population in the risk areas of inundation is 1.255 million, about 2.6% of total population. This result suggests that the coastal zone of Korean Peninsula is quite vulnerable to the 21st sea level rise. The west coastal zone is appeared to be the most vulnerable area compared to the east and south. In the western side of the Korean Peninsula, the North Korea appears to be more vulnerable than South Korea. The vulnerability assessment in the present study assumes the maximum emission scenario of IPCC SRES (Special Report on Emission Scenario) and does not consider the retention time of the typhoon, and coastal dike and seawalls. Thus the inundated area and population in the present study represent the possible maximum area and population, which indicates the degree of a potential vulnerability in the coastal zone of Korea. The basic approach to deal with the problem of sea level rise requires both mitigation and adaptation. Though the emission reduction of greenhouse gases can reduce a portion of sea level rise, the sea level rise trend in the 21st century cannot be avoided due to the difficulties of the emission reduction and a strong inertia of the ocean. Therefore an effective direction corresponding to the sea level rise problem has to lie on the development of appropriate adaptation strategies, especially in the regional and national scales. For the development of appropriate adaptation strategies on the Korea coast vulnerable to the sea level rise, we have to consider the issues such that where to adapt, how to adapt, and when to adapt. The coastal target needed adaptation can be found by the evaluation of adaptive capacity of the coastal zone which requires the understanding of impacts and adaptive potential of the natural and socioeconomic systems in the coastal zone. The adaptive potential of coastal zone includes the autonomous and planned (predictive and reactive) adaptive capacity. Planned adaptation options to sea level rise can be classified into three generic approaches such as managed retreat, accommodation, protection. The protection option can be further classified into hard structural options such as dike and soft structural options such as beach nourishment. In practice, the implementations of the options above require the analysis of land use, degree of vulnerability, costs and benefits, etc and may be combination of the options rather than one approach. For the expected adverse impacts in the coastal zone due to the sea level rise, appropriate timing of the response is needed. In terms of the response timing, the adaptation can be classified as anticipatory and planned ones. Generally it is more effective to consider both anticipatory and planned adaptations at the same time for the impacts of future sea level rise. The anticipatory adaptation can be enhanced with the protection and augmentation of the autonomous adaptive capacity through the examination of existing coastal development way such as the damage of tidal flat, dune, and so on. Integration of the adaptation measures to the sea level rise impact into Integrated Coastal Zone Management (ICZM) would be the most appropriate way to respond the impact of future impact of sea level rise and climate changes. The responding system of Korea to the sea level rise appears to be vulnerable as much as the coastal zone of Korea. The vulnerability of responding system involves with the lacks of responsible organization, experts, awareness, appropriate strategies, implementation of established strategies, and so on. Therefore the responding system to deal with the climate impact problems including sea level rise is urgently required. Because the climate change issues including sea level rise problem have to be dealt under scientific uncertainty, the corresponding system have to be designed to deal with the processes of information and awareness, planning and design, implementation, and monitoring and evaluation in continuity and long-term period. The future task corresponding effectively to the sea level rise problem in Korea includes the development of scientific information on sea level rise near the Korean coasts and regional prediction, the development of adaptative measures based on detailed vulnerability assessment, enhancement of people awareness on sea level rise and global warming issue, consensus formation of corresponding necessity, and formation of integrated corresponding system to deal with the sea level rise issues.