• Journal of Korea Water Resources Association
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• v.47 no.9
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• pp.743-752
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• 2014

Delay time for groundwater recharge means the travel time from the bottom of soil layer to groundwater through vadose zone after infiltration from rainfall. As it is difficult to measure delay time, we suggested an empirical formula which is derived by using linear regression between altitude and delay time. For the regression analysis, 4 major gauging watersheds were chosen (Hancheon, Kangjeongcheon, Oedocheon, Cheonmicheon) with 18 measured groundwater level stations. To verify this empirical formula, derived equation from linear reservoir theory was applied to compute delay time and to compare estimated amounts of groundwater recharge using both methods. The result showed good agreement. Furthermore, if derived empirical formula would be linked with SWAT model, the spatial time delay effect in the watershed could be reflected properly.

• Proceedings of the Korea Water Resources Association Conference
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• 2019.05a
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• pp.211-211
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• 2019

본 연구의 목표는 제주도를 대상으로 한 강우-유출 과정에서 적절한 CN값의 결정 및 초기손실의 규모를 판단하는 것이다. 제주도는 화산 활동으로 형성된 섬으로 투수성이 좋은 다공질 화산암류 및 화산회토로 이루어져 침투가 쉽게 발생한다. 이러한 토양 특성으로 인해 제주도 유역의 유출해석 수행 시 내륙지역과 동일한 방법을 적용하는 데 한계가 있다. 기존 제주도의 강우-유출연구를 살펴보면 초기손실의 고려방법이나 선행함수조건의 고려방법이 달라 상대적인 비교가 모호해지는 문제가 있다. 또한 고려방법에 따라 유출해석 결과가 서로 상충되기도 하여 유의한 결론을 제시하는데 무리가 따른다. 이에 본 연구에서는 제주도 지역의 CN 및 초기손실에 대한 검토를 수행하였다. 이를 위해 대상유역은 한천 유역으로 선정하였으며, 호우사상은 2012년과 2014년에 발생한 태풍 '카눈', 태풍 '볼라벤', 태풍 '산바', 태풍 '나크리' 호우사상을 적용하였다. 한천 유역의 CN과 초기손실에 대한 검토를 위해 강우 자료는 대상 유역 인근 제주(184), 아라(329), 어리목(753), 진달래밭(870), 윗세오름(871) 지점의 강우 자료를 이용하였으며, 유출량 자료는 한천 하류에 위치한 제4한천교에 관측된 수위 및 유속 자료를 이용하였다. 먼저 각 호우사상별 총 유출량을 기저유출과 직접유출으로 분리하고 직접유출량에 대한 유호우량을 산정하였다. 다음으로 산정된 유효우량을 NRCS의 유효우량 산정방법에 적용되는 총 유량-유효우량 관계모형에 적용하여 유역의 최대잠재보유수량을 산정하였다. 이때 초기손실량은 유역의 최대잠재보유수량의 20%, 30%, 40%로 가정하였다. 마지막으로 산정된 최대잠재보유량을 최대잠재보유수량-CN 관계식에 적용하여 CN을 산정하고, 기존 연구에서 적용한 한천 유역의 CN과 비교하여 그 결과를 검토하였다.

• Journal of the Korean Institute of Landscape Architecture
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• v.38 no.1
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• pp.98-106
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• 2010

Bangseonmun(訪仙門) is the attractive spots where Shinseon(神仙: Taoist hermit) ideas that makes Mt. Younju(瀛洲山) or the current Mt. Halla mystique has still remained and situated at Hancheon(漢川) Valley. Bangseonmun, which is known as 'Landscape Setting Here($L_{SH}$)' of Youngguchunhwa(瀛丘春花), which is one of ten famous spots in Youngjusipkyung(瀛洲十景), and Deulreonggui refer to 'the gate to the place where Shinseon is living.' It is described as the path to Mt. Youngju for Shinseon and the boundary between the mundane world and the world beyond the mundane. The old scholars at Mt. Halla entered the gate and met Shinseon, carving the word or picture of Bangseonmun, Whanseonmun, Wuseondae or Deungyounggu so as to structure the enchanting image on Bangseonmun. It is the poetic expression of the taste for the arts, breaking from the troublesome mundane world and riding the white deer to become the Shinseon, the desire for the ideal world in Taoism, and the identity of four famous scenic spots of Bangseonmun. Besides its enchanting meaning and the locational value of Bangseonmun, geological features of the valley and river and ecological value prove its unique value as a natural scenic beauty. Not to mention the locational identity and enchanting meaning of the poets carved in Meeaegak of Bangseonmun and the scenic view of 'Youngguchunhwa' as the subject of 10 famous scenes of Youngju, it is the place for communing with nature with the natural beauty of Bangseonmun Valley. As the cultural place for being together with Jeju people, it simultaneously shows the typical model as a scenic spot in our living. Viewing the scenic value and standard from the aspect of the Cultural Properties Protection Law, Bangseonmun Valley in Jeju must be the typical place and space that meet the requirements to become scenic sites.

• Journal of Korea Water Resources Association
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• v.51 no.12
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• pp.1261-1271
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• 2018

This study evaluates the applicability of the classification rule of hydrological soil group proposed by Lee et al. (2018) with its application to three river basins (Jungmuncheon, Cheonmicheon, and Hancheon) in Jeju Island. The CN values are estimated as results of this application to these three basins, which is then compared with those estimated by applying the conventional three methods. Additionally, previous studies related with the classification of soil groups of Jesu Island, such as the infiltration and rainfall-runoff analysis, are reviewed to evaluate how the resulting hydrological soil groups vary depending on the adopted classification method.. Summarizing the results is as follows. (1) Comparison result of the hydrological soil groups of Jeju Island with respect to the classification method shows that the soil group B is dominant in the application of Lee et al. (2018). However, it is hydrological soil groups C and D in the application of Hu and Jung (1987), hydrological soil groups A and C in the application of Jung et al. (1995), and hydrological soil group D in the application of RDA (2007). (2) In all the applications of Lee et al. (2018) to three selected river basins in Jeju Island, the CN valuse are found to be smaller than those by other conventional three methods.. Lastly, (3) The evaluation results of previous studies related with the classification of hydrological soil groups analysis in Jeju Island shows that the CN value in the Jeju Island may be smaller than those estimated by conventional three methods, also the initial loss higher than 0.2S.