태안해안국립공원은 우리나라 유일의 해안국립공원으로 대표적인 4개 섬인 외도, 대도, 장고도, 그리고 가의도에 대해 식생특성을 밝혔다. 각 섬마다 식생구조를 밝히고 비교를 하기 위하여 단위면적 100mm2의 조사구 4개씩을 균등하게 설치하였다. 4개 섬에 대해 각각의 식생구조를 분석한 결과 외도와 장고도는 곰솔군락이 우점종이었으며, 고대도는 곰솔-소나무군락, 가의도는 소사나무-소나무군락이 우점종이었다. 그러나 각 섬의 물리적 환경에 따라 같은 곰솔이나 소나무군락이라도 종조성에 따라 차이가 있었다. Ordination과 유사도분석결과 외도와 가의도의 유사도가 6.58%로 가장 낮았으며, 종다양도(2.7183) 및 개체수 분석 결과 가의도가 가장 높은 것으로 나타났다.

Hydrologic component analysis was conducted to investigate water budget characteristics the Oedocheon watershed, Jeju Island. For this purpose, integrated SWAT-MODFLOW model was applied to this watershed for continuous surface water-groundwater modeling. Pasture and forest-deciduous are the major land use types and these affect general hydrologic component ratio. The spatio-temporal groundwater recharge can be obtained from SWAT and then distributed groundwater recharge can be reproduced by MODFLOW. The groundwater level variation was simulated with distributed groundwater pumping data. The water budget in this watershed was compared with the previous estimated result by Jeju-Do(2013). As this result considered discharge to the coastal side, the discrepancy was found. However, it was found that the overall tendency of both analyses were similar.

Rainfall-runoff model of Jeju Oedo Stream was used to compute the optimal unit hydrograph by HEC-HMS model that reflecting on watershed characteristics. Each rainfall event was comparatively analyzed with the actual flow measurement using Clark, Snyder and SCS synthetic methods for derived unit hydrograph. Subsequently, the null hypothesis was established as p-value for peak flow and peak time of each unit hydrograph by one-way ANOVA(Analysis of variance) was larger than significance level of 0.05. There was no significant difference in peak flow and peak time between different methods of unit hydrograph. As a result of comparing error rate with actual flow measurement data, Clark synthetic unit graph best reflected in Oedo Stream as compared to other methods, and error rate of Clark unit hydrograph was 0.02~1.93% and error rate at peak time was 0∼2.74%.

Since Jeju island has depended a water resource on the underground water because of a poor development of the surface flow, Jeju island is in need of the surface resource development to prevent the future shortage of the underground water due to excessive development and use of it. The study shows that the SWAT model(continuous rainfall-runoff model) is applied to estimate the outflow in the drainage watershed area, where it has been urbanized through the change of the land, such as a tourism development, cultivation, housing, and impervious layer road development. Near Oaedo watershed area in Jeju island, weather and topographical SWAT input data were collected, and compared the outflow change of past and present.