Eight-year monitoring of the height growth and survivorship of seedlings of Pinus thunbergii Parl. planted with sand fence and bush hedge protection in a coastal sandy environment in Korea

Ewane Basil Ewane,이주형,이헌호 한국산림과학회 2016 Forest Science And Technology Vol.12 No.4

This study aimed to examine the effect of distance at three levels (5 m, 15 m, and 25 m) of ranges of plots landwards from a sand fence and bush hedge protection margin on the height growth and survival of seedlings of Pinus thunbergii Parl. planted in a coastal sandy environment in Uljin, East Sea area of Korea. The purpose of the study was to investigate height growth and survival with distance from a bush hedge/sand beach boundary of pine seedlings in a coastal forest plantation. Seedling height growth and survivorship were measured annually in nine plots, with three plots each selected from three ranges of plots at distances of 5 m, 15 m, and 25 m landward from the bush hedge/sand beach boundary from 2007 to 2014, 8 years after planting. Annual averages in seedling height growth significantly reduced in the 2nd and 3rd years of growth but appreciably stabilized from the 4th to 8th year, indicating that the 2nd and 3rd years of seedling growth and survival in the study site were the most critical. We found no statistically significant differences in height growth and survivorship of the planted seedlings between the three ranges of plots at distances of 5 m, 15 m, and 25 m landward from the bush hedge/sand beach boundary in the microsite. This suggested that seedling height growth and survivorship were not significantly affected by the distance factor. This was attributed to the protective and stabilization functions of the bush hedges and sand fence barrier, which reduced near-surface wind damage to seedlings and fostered a relatively uniform height growth and survival of the planted seedlings in the microsite. Furthermore, wind speed (P D 0.014) and soil moisture at 12 cm depth (P D 0.014) were the most significant of the selected factors limiting the height growth of the seedlings in the study area, as they accounted for 94.4% (R2 D 0.944) of the insignificant variability associated with the distance factor. The results provide supportive evidence that sand fence and bush hedge micro-windbreaks can be reliably used to protect, stabilize, and sustain relatively uniform height growth and survival of seedlings of P. thunbergii planted in a windy coastal sandy environment and in other locations with similar soil and climatic conditions.

학술연구논문 포스터발표 : 3분과: 산림공학, 사방, 토목, 벌채 ; 독일 흑림지역에 위치한 산지고층습원의 토양특성

정유경,이헌호,이기환,박기영,( Ewane Basil ) 한국임학회 2013 한국임학회 학술발표논문집 Vol.2013 No.-

Correlation between above-ground and below-ground biomass of 13-year-old Pinus densiflora S. et Z. planted in a post-fire area in Samcheok

김도현,김재희,박진화,Ewane Basil Ewane,이도형 한국산림과학회 2016 Forest Science And Technology Vol.12 No.3

This study was carried out in order to explore and compare the correlation between each measured item of the aboveground and below-ground biomass of 13-year-old Pinus densiflora S. et Z. and prepare regression equations to identify differences of early growth characteristics on each slope aspect in the stand. The south-facing slope showed the highest above-ground and below-ground biomass, followed by the north-facing slope and ridge area. The root collar diameter showed the highest correlation between the biomass of the above-ground part and the below-ground part. In the linear regression equation on the root collar diameter and the biomass of the above-ground part and the below-ground part, the growth gradient was high in the south-facing slope and north-facing slope and low in the ridge area such that the biomass in the ridge area may well continue to be low in the future as the trees grow. The result of the study demonstrated that the differences in the growth environments associated with differences in the slope aspect had a significant influence on the early growth of trees. The results of this study further manifested the importance of the concept of slope direction in artificial forestation and could be used as preliminary data to support artificial forestation measures in the future.

토사유출량 모니터링을 위한 소류사 관측장비의 시공

이헌호 ( Heon Ho Lee ),( Ewane Basil Ewane ),이창우 ( Chang Woo Lee ),서준표 ( Jun Pyo Seo ),박기영 ( Ki Young Park ) 한국임학회 2014 산림과학 공동학술대회 논문집 Vol.2014 No.-

토사유출량을 예측하기 위해 개발된 토사유출량 산정공식은 일부 지역에 적합하도록 개발되어 있다. 따라서 우리나라에 적합한 토사유출량 산정공식의 개발이 필요하며, 이를 위해선 토사유출량의 정량적인 평가가 필요하다. 하지만 우리나라에서 사용되는 기계식 소류사 채취방법은 그 관측치의 정도가 낮고 시계열적 모니터링이 불가능하여 정확한 토사유출량의 관측에 어려움이 있다. 이는 우리나라에 적합한 토사유출량 산정공식의 개발에 문제점으로 지적되고 있다. 따라서 향후 우리나라에 적합한 토사유출량 산정공식의 개발에 기초자료가 될 수 있는 토사유출량의 정량적이고 시계열적인 모니터링을 위하여 하이드로폰과 피트유사계를 시공하였다. 하이드로폰은 소류사가 충돌할 때 발생하는 소리를 통해 유사량을 계산하는 원리이다. 설치 시 종·횡단방향으로의 수평과 시공의 편의를 위해 사방댐과 바닥막이 같은 횡공작물에 설치하는 것이 용이하다. 소류사의 충돌을 위해 하이드로폰의 상부 5~10cm가량을 노출시키고 하부는 콘크리트를 타설하여 구조물에 고정한다. 피트유사계는 내부의 스테인리스 틀에 소류사가 퇴적될 때의 중량을 통해 유사량을 계산하는 원리이다. 설치 시소류사의 퇴적을 위해 하상과 일직선상으로 설치하여야 한다. 현재 국내의 소류사 연구는 소류사 관측의 어려움으로 더디게 진행되고 있다. 따라서 정량적이고 시계열적 모니터링이 가능한 관측장비의 도입으로 소류사와 관련된 연구가 활발히 진행될 것으로 기대된다. Soil erosion formulas to some extent provide universally suitable alternative for estimating soil loss, but there is need to find a suitable soil loss formula for Korea, which can ensure necessary measurement accuracy. Stream bed load measurement, typically used in Korea does not provide the required accuracy or real time measurements, thus, increasingly cannot be relied upon for precision measurement outcome. Because of the limitations of the above methods in quantitative soil erosion measurement and the need to acquire reliable and accurate data base to create a soil erosion formula suitable for Korea, we resourced to the accuracy of a hydrophone and pit to estimate sediment flow. The hydrophone estimates sediment discharge through a sound system, which echoes as the stream bed load collides with the hydrophone equipment installed with concrete on a debris barrier or cross structure on a stream channel and made to outcrop 5 cm to 10 cm above the debris barrier platform that forms the stream bed. The pit estimates sediment discharge through the weight of the bed load sediment flow, thus, must be installed straight with the stream bed to cause a pile up of the bed load. This new observation equipment and method of stream bed load estimation offers impressive progression to our accuracy in sediment flow measurement studies.

외관상태평가를 이용한 콘크리트 사방댐의 노후특성 분석

이헌호 ( Heon Ho Lee ),박기영 ( Ki Young Park ),( Ewane Basil Ewane ),권태호 ( Tae Ho Kwon ),오세욱 ( Se Wook Oh ),이기환 ( Ki Hwan Lee ) 한국임학회 2014 산림과학 공동학술대회 논문집 Vol.2014 No.-

본 연구는 시설물 안전진단 기법인 외관상태평가를 이용하여 콘크리트 사방댐의 노후특성을 객관적이고 정량적으로 평가하고자 하였다. 평가는 1986년과 1993년에 준공한 콘크리트 사방댐 2개소를 대상으로 실시하였다. 1986년에 준공한 콘크리트 사방댐에서 월류부의 상태평가지수는 3.3으로 비월류부의 4.3보다 낮았고, 반수면의 상태평가지수는 2.6으로 댐마루의 3.6보다 낮았다. 그리고 사방댐의 종합 상태평가지수는 3.3으로 c등급을 나타내었다. 1993년에 준공한 콘크리트 사방댐은 월류부의 상태평가지수가 2.4로 비월류부의 3.7보다 낮았으며, 반수면의 상태평가지수는 2.2로 댐마루의 3.3보다 낮았다. 그리고 종합 상태평가지수는 2.5로 긴급한 보수, 보강이 요구되는 d등급을 나타내었다. 콘크리트사방댐의 노후상태는 사용기간이 늘어날수록 심화되지만, 시공품질과 사용환경에 따라 열화속도에 차이를 보이며, 특히 수분과의 접촉이 잦은 부재일수록 노후하기 쉬운 것으로 판단된다. This study aim to objectively and quantitatively assess the features of concrete debris barriers using the exterior condition assessment, in order to examine the safety of the facility. The assessment was conducted on two different concrete debris barriers constructed in 1986 and 1993. The weir of the debris barrier built in 1986 was observed to have a condition assessment index of 3.3, which was lower than the 4.3 measured in the non-weir section, and the downstream face of the dam had a condition assessment index of 2.6, which was lower than the 3.6 of the dam crest section. Our comprehensive assessment determined the dam built in 1986 of fall in grade C, considering an observed condition assessment index of 3.3. The weir of the debris barrier built in 1993 was detected to have a condition assessment index of 2.4, which was lower than the 3.7 measured in the non-weir section, and the downstream face had a condition assessment index of 2.2, which was lower than the 3.3 measured in the dam crest section. Based on our comprehensive analysis, we concluded that the debris barrier built in 1993 needs urgent repair and reinforcement work, considering its condition assessment index of 2.4, Which falls in grade D. The suggests that concrete debris barriers would deteriorate faster because they are used even more and longer but the deterioration can be delayed or accelerated depending on their construction quality and where they are used. Particularly, our observations strongly hold that concrete debris barriers, which would be frequently in contact with moisture, can deteriorate more easily if they were made from poor quality materials.