A numerical simulation for 11 February 1996 has been done to grasp main mechanisms of the occurrence of strong downslope winds near Gangnung area. The simulation performed by using ARPS (Advanced Regional Prediction System) showed that enhanced surface winds were not related with a reflection of vertically propagating gravity waves. Froude numbers were about 1.0, 0.4 and 0.6 for the atmosphere above Daekwanryoung and above a place located 220 km upstream, and above another place located 230 km downstream from the Taebak mountains, respectively. This suggested that as a subcritical flow ascended the upslope side of the Taebak mountains, Froude numbers would tend to increase according to the increase in wind speed, and near the crest the flow would become supercritical and continue to accelerate as it went down the downslope side until it was adapted back to the ambient subcritical conditions in a turbulent hydraulic jump. Simulated Froude numbers corroborated the hydraulic jump nature of the strong downslope wind. In addition, the inversion was found near the mountain top height upstream of the mountains, and it was favorable for the occurrence of strong downslope winds.

Foehn damage on rice plant is one of the important abiotic stresses in eastern costal area of Korea. To know the relationship between foehn impact and morphological traits of rice, wind tunnel method was used with 106 rice cultivars. Less influencing traits on foehn were short panicle, large panicle number per hill, thin panicle neck, and the flag leaf of narrow, short and thick. Leaf pubescence reduced the impact on foehn. 'Naepungbyeo' belong-ed to foehn tolerant varietal group, while 'Ansanbyeo' belonged to the opposite group. Three levels of root cutting treatment with two rice cultivars were conducted to evaluate the foehn impact using wind tunnel. The severity of wind damages was followed the sigmoidal curve duration of wind tunnel treatment were prolonged. Different responses of root cutting to wind tunnel treatment could be used to evaluate the severity of the foehn impact. 'Naepungbyeo' was one of the less implausible cultivars on foehn. 'Nae-pungbyeo' showed tolerant response to wind under 21% root removing treat-ment (20㎝ root cutting), however 'Ansanbyeo' was wilted under the same treatment. In case of 35 % root removing treatment(10㎝ root cutting), both rice cultivars failed to alive against foehn wind.

In order to make use of the protection effect against wind by the vegetation, it examined whether it should make what vegetation form and arrangement using the 2-dimensional non-hydrostatic model. When the foliage shielding factor increases, it becomes hard to take in protection effect against wind in a residential section. When it makes height of vegetation high, it becomes hard to take in protection effect against wind with height. In the comparison in the case where vegetation high is gradually made low toward wind-stream from a vegetation, and the case of making it low gradually, although former tends to receive the protection effect against wind by the vegetation, attenuation of wind velicity becomes large. In the comparison in the case where foliage shielding factor and distribution of density of leaf are gathered gradually toward wind-stream from a vegetation. It has been understood to evaluate to height the influence that the vegetation multi-layer model by which the heat revenue and expenditure in the direction of the vegetation height is considered is used, and to characterize the vegetation group by the parameter setting.

In establishing artificial fences in a certain locality, type of its area or wind blown against them from the front side is primarily considered. Researchers on fences also concentrate on upstream, wind blown against them from the front side in 90° angle. In this research, simulations were carried out on the direction of wind changed by each season, and regardless of seasonal wind, on the fences effect of wind direction on fences, through an atmospheric boundary layer wind tunnel. When I compared the velocity distribution of upstream against the fences in 90° angle with that of 75°, 60°, and 45˚ respectively, the velocity distribution at downstream of the latter cases generally surpassed that of the former one.

동해안 랭조풍지대의 풍해 대표지역인 경북 영덕지방에서 1986년부터 1989년가지 4개년간 방풍강의 강목에 다른 풍해 경감효과와 농가포장 설치효과를 종합하면 다음과 같다. 1. 동해안 랭조풍지대의 1979년부터 1989년까지 11년간 태풍에 의한 백수 피해의 발생빈도는 8월 10일부터 9월 10일 사이에 높아 이 지역의 수도 안전출수한계기는 8월 10일 이전이 안전하다고 생각된다. 2. 이 지대는 태풍 통과시 증발계수가 250이상으로 높아 백수피해 위험도가 높으며 풍해를 유발시키는 바람의 종류는 태백산맥을 넘어오면서 휀(Fohn) 현상에 의한 고온건조한 편서풍과 해양에서 내륙으로부터 한랭과습한 랭조풍이었으며 도작기간중 발생빈도는 각각 25, 20%였다. 3. 방풍강 설치에 의한 풍속 감속효과는 방풍강의 강목이 좁을수록 컸으며, 방풍강이 설치된 지점으로부터 1m 거리에서는 23%, 10m 거리에서는 34%, 20m 거리에서는 28%였으며 그 효과는 설치된 방풍강 높이의 10배까지 있었다. 4. 방풍강 설치에 의한 기상개선효과는 무방풍구에 비해 방풍강의 강목이 좁을수록 컸으며 기온은 최고 0.8℃ , 최저 0.7℃ , 평균 0.6℃ 상승되었고 수온은 최고 0.5℃ , 최저 0.6℃ , 평균 0.5℃ 상승되었으며 지온도 0.4℃ 상승되었다. 5. 방풍강에 의한 생육개선효과는 무방풍구에 비하여 방풍강의 강목이 좁을수록 컸으며 출수촉진, 개체군 생장속도 및 광이용율 증진, 간장신장, 주당수수, 수당영화수, 임실율, 천립중 등이 증가하여 방풍강의 강목(0.5 0.5cm)에 따른 증수효과는 10%, 농가포장 설치효과는 15% 증수되었다. 6. 답면수온이 낮은 동해안 랭조풍지대에서는 주당묘수를 늘리는 것이 수수 확보에 유리하여 13% 증수효과가 있었으며 그 효과는 무방풍구에서 더욱 현저하였다. 7. 방풍강 설치에 의한 풍속 경감으로 동화기관의 고엽방지효과로 완전미의 비율이 높아 미질개선의 효과가 있었으며 벼알의 변색정도가 감소되었고 변색정도가 심할수록 증숙율과 천립중이 떨어졌으며 그 정도와 부의 상관관계가 있었다. 이상의 결과를 종합하면 태풍 발생빈도가 높은 동해안 랭조풍지대에서는 품종과 이앙기를 조절하여 풍해를 회피하거나 방풍림이나 방풍강을 설치하여 풍해를 경감시키는 것이 수량 생산의 안전성을 향상시킬 수 있을 것으로 생각된다.