厦门岛东北岸海岸风沙运动观测研究

OBSERVATION AND RESEARCH OF COASTAL AEOLIAN IN NORTHEAST OF XIAMEN ISLAND

厦门岛东北海岸是台湾海峡西岸风沙最活跃的岸段之一,其中香山-五通岸段由于新建设了宽阔的人造海滩,风沙更加肆虐。为了解该岸段海岸风沙的运动特征和影响程度,分别于2007年11月22日、12月31日和2008年1月13日使用捕沙器定时取样和同步风速观测的方法进行风沙观测。结果如下:(1)人造海滩的风沙起沙风速约为6.9m/s,该风速以上,风沙随风速的增加而增加;(2)海岸风沙在离地面1m高度内运动,其中的94.8%在0.25m高度下运行;(3)人造海滩的风沙粗于自然海滩的风沙,随风沙运动高度从低到高,平均粒径由细到粗,分选性变好;(4)本岸段>6.9m/sNE风时平均输沙率约为2.776kg/m2h,单宽输沙量约为374.84kg/h,即8.995t/d.

Coastal aeolian sand transport in northeast of Xiamen island is among the most active area of west shoreline of Taiwan Strait recently, coastal aeolian sand transport is more serious because artificial beach was bulit from Xiangshan coast to Wutong coast. In order to understand the coastal aeolian transport features and the extent of the impact, aeolian observation was carried out by using streamer sand trap sampling timing and synchronization methods of observing wind speed, respectively, in November 22, December 31, 2007 and January 13, 2008. The results are as follows： 1） The threshold velocity of sand of artificial beach is about 6.9m/s. When the velocity is more than 6.9m/s, the sediment discharge can be increased as the velocity is rising higher. 2） Coastal aeolian sand transported under lm height level, which about 94.8M of coastal aeolian sand transported under 0.25m height level. 3） The grand size of aeolian sand from artificial beach is bigger than aeolian sand from natural beach. The mean grand size of aeolian sand is increasingly bigger and the standard deviation is increasingly lower as the height level of aeolian sand transport is higher. 4） The average transport rate and transport rate of unit width is 2. 776 kg/m2h, 374.84 kg/h （about 8. 995t/d） especially when the wind speed is more than 6.9m/s NE.