采用样线法,对福建平潭长江澳木麻黄基干林带及工程沙障各季度防风效能和粗糙度进行评价,并将防风效能指标与测树因子进行相关性分析。结果显示：（1）基干林内各季度各梯度林带随着距迎风面距离的增加,风速逐渐下降,防风效能和粗糙度...采用样线法,对福建平潭长江澳木麻黄基干林带及工程沙障各季度防风效能和粗糙度进行评价,并将防风效能指标与测树因子进行相关性分析。结果显示：（1）基干林内各季度各梯度林带随着距迎风面距离的增加,风速逐渐下降,防风效能和粗糙度逐渐上升；（2）各季度基干林内0～150 m范围,在2 m、1.5 m 和0.5 m 高度处,总体上分别存在3个、5个和4个差异显著（P〈0.05）的风速梯度,3个、4个和4个差异显著（P〈0.05）的防风效能梯度,4个差异显著（P〈0.05）的粗糙度梯度；（3）工程沙障各季度均存在较明显的防风效能和粗糙度；（4）除了冬季防风效能、粗糙度、树高和胸径相关性不显著外,其他各季度各指标间均存在极显著的相关性（P〈0.01）,风速与防风效能、粗糙度、树高和胸径呈负相关,可决系数R^2≥｜-0.680｜,防风效能、粗糙度、树高和胸径间呈正相关,可决系数R2≥0.490；（5）根据目前木麻黄基干林带的经营方式,至少应营建150 m宽的基干林带,才能有效降低海岸风口风速。展开更多
Wind velocity reduction of coastal shelterbelt system was monitored for 1 month in 3 weather stations in Nanhui,Shanghai,and the benefits of shelterbelt system and trunk shelterbelt forest were compared in this paper....Wind velocity reduction of coastal shelterbelt system was monitored for 1 month in 3 weather stations in Nanhui,Shanghai,and the benefits of shelterbelt system and trunk shelterbelt forest were compared in this paper.The results showed the wind velocity at the first weather station(W1),which located in front of trunk shelterbelt forest by the seaside,was the biggest,with the average of 9.36 m/s;the wind velocity at the second weather station(W2) was lower than that at W1,with the range of 0 to 18.2 m/s and the average of 6.39 m/s,and the wind velocity at the third weather station(W3) was the lowest,with the average of 2.58 m/s.Both the ratio of W2 to W1 and the ratio of W3 to W1 ranged from 0 to 100%,but most of the ratio of W2 to W1(89.59%) was above 20%,and most of the ratio of W3 to W1(95.52%) was below 50%,which shows bigger wind velocity reduction in shelterbelts system than in trunk shelterbelt forest.With the wind scale increased from 1 to 8 scale at W2 and W3,the wind velocity increased.But the reduction in wind velocity decreased.展开更多
文摘采用样线法,对福建平潭长江澳木麻黄基干林带及工程沙障各季度防风效能和粗糙度进行评价,并将防风效能指标与测树因子进行相关性分析。结果显示：（1）基干林内各季度各梯度林带随着距迎风面距离的增加,风速逐渐下降,防风效能和粗糙度逐渐上升；（2）各季度基干林内0～150 m范围,在2 m、1.5 m 和0.5 m 高度处,总体上分别存在3个、5个和4个差异显著（P〈0.05）的风速梯度,3个、4个和4个差异显著（P〈0.05）的防风效能梯度,4个差异显著（P〈0.05）的粗糙度梯度；（3）工程沙障各季度均存在较明显的防风效能和粗糙度；（4）除了冬季防风效能、粗糙度、树高和胸径相关性不显著外,其他各季度各指标间均存在极显著的相关性（P〈0.01）,风速与防风效能、粗糙度、树高和胸径呈负相关,可决系数R^2≥｜-0.680｜,防风效能、粗糙度、树高和胸径间呈正相关,可决系数R2≥0.490；（5）根据目前木麻黄基干林带的经营方式,至少应营建150 m宽的基干林带,才能有效降低海岸风口风速。
基金supported by National Project of Scientific and Technical Supporting Programs Funded by Ministry of Science and Technology of China (2009BADB2B0301)Research Institute of Sub-tropical Forestry Fund (RISF6923)
文摘Wind velocity reduction of coastal shelterbelt system was monitored for 1 month in 3 weather stations in Nanhui,Shanghai,and the benefits of shelterbelt system and trunk shelterbelt forest were compared in this paper.The results showed the wind velocity at the first weather station(W1),which located in front of trunk shelterbelt forest by the seaside,was the biggest,with the average of 9.36 m/s;the wind velocity at the second weather station(W2) was lower than that at W1,with the range of 0 to 18.2 m/s and the average of 6.39 m/s,and the wind velocity at the third weather station(W3) was the lowest,with the average of 2.58 m/s.Both the ratio of W2 to W1 and the ratio of W3 to W1 ranged from 0 to 100%,but most of the ratio of W2 to W1(89.59%) was above 20%,and most of the ratio of W3 to W1(95.52%) was below 50%,which shows bigger wind velocity reduction in shelterbelts system than in trunk shelterbelt forest.With the wind scale increased from 1 to 8 scale at W2 and W3,the wind velocity increased.But the reduction in wind velocity decreased.
