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本题通过对海南岛南岛农场1962—70年种植的PB86、RRIM600两个无性系的累计风害状况的调查,以探求山区橡胶树在不同地形条件下的风害规律,得出以下结论: 1.山区由于地形起伏,起到相互屏蔽的作用。试以每平方公里面积内的山头个数表示地面的粗糙度,以其他条件类似的相邻小区成对相比较,结果表明:山头密度大的小区,风害率低4.3～29.8％,风害级低0.11～1.2级。 2.在迎台风来向的主要路径上,如有高山阻挡则背风一侧的明显影响范围约为相对高差的10～20倍。 3.在迎台风来向的主要路径上,如有山同缺口时,则由于窄管效应,必导致风害加剧,成为风害最重的局部地段。 4.由山间缺口和由翻越高山屏障侵入的台风,往往沿着与台风路径相一致的低平地、水面、河道、山谷、道路形成“风路”,在“风路”上的橡胶树较位于山间缺口地段的胶树风害轻。 5.不同走向的山谷、不同开口方向的山洼地以及不同坡向的地段,其风害状况都与台风主要路径的走向有关,但在局部地段,由于山区地形的作用,又必须结合“风路”的各种状况,加以具体分析。 6.在坡面上,不论是迎风坡或背风坡,都是坡中部位的胶树风害重于同坡面的上、下坡位,只有在山前为开阔平地的迎风坡面,则中、下坡位胶树的风害均重于上坡。坡脊线及变坡线附近,均是风害加重的部位。 7.山区有良好的避风小环境,诸如有高山作屏障的保护范围,又如西南→东北走向的山谷,或西、北坡向等均是静风小环境,应充分发挥其优势。 8.山区防护林的技术设计,即使在一个农场的范围内,也应按不同地段的风害轻重加以具体设计。这与平地的林带设计是不相同的。
Based on the investigation of the cumulative wind damage status of PB86 and RRIM600 clones planted in South Island farm in Hainan Island from 1962 to 1970, the following conclusions are drawn: 1. Due to the mountainous terrain, play a role in shielding each other. The surface roughness was expressed as the number of hills per square kilometer and compared with the adjacent areas in other similar conditions. The results showed that the wind densities were 4.3 ~ 29.8% Level low 0.11 ~ 1.2 level. 2. In the main path to the typhoon, the obvious influence range of the leeward side is about 10 ~ 20 times of the relative elevation difference if the mountain is blocked. 3. On the main route to the typhoon, if there is a gap between hills and mountains, the narrow-pipe effect will lead to the worsening of wind damage and become the most localized part of the wind damage. 4. Typhoons invaded by mountainous gaps and invaded by alpine barriers often form “airways” along low-lying terrain, waterways, rivers, valleys and roads that are consistent with typhoon paths, and rubber trees on “airways” Gaps in the gap between the plastic jungle wind light. 5. In different valleys and valleys with different opening directions and sections with different slope directions, the wind damage conditions are all related to the trend of the main typhoon course. However, due to the mountainous terrain, some wind tunnels must be combined with the “wind tunnel ”A variety of conditions, to be specific analysis. 6. On the slope, either the windward slope or the leeward slope, the gum tree winds on the slope are heavier than the upper and lower slope positions of the slope, and only on the windward slope of the open ground in front of the mountain, In the downhill bit gum tree wind damage are all on the uphill. Slope ridgeline and slope near the line, are the site of increased wind damage. 7. Mountain areas have a good shelter environment, such as the protection of mountains as a barrier, but also from the southwest → northeast valley, or the west and north slopes and so on are quiet small environment should give full play to its advantages. 8. The technical design of mountain shelterbelts should be designed specifically for the severity of wind damage in different locations, even in the context of a farm. This is not the same as the design of the strip in the plain.