海南博鳌玉带沙海滩冲淤演变及脆弱性分析

摘要

玉带沙是海南岛东部博鳌万泉河口的一条细长沙嘴,也是我国重要旅游海滩之一。为了揭示近期玉带沙的冲淤演变趋势,选择了1988年以来4个年份的RS图像,利用现场GPS监测的海滩地形推算出校正后的低潮位水边线,并使用GIS软件计算各年份低潮线以上的玉带沙面积。结果表明：1988～2005年玉带沙呈显著蚀退趋势,平均蚀退70m（4.1m/a）,面积减少35%。分析认为：玉带沙蚀退主要原因是海平面上升和万泉河入海泥沙的减少。在气候变化与人类活动的双重作用下,玉带沙呈现高度脆弱性,值得关注。%Yudaisha is a slender spit of Wanquan estuary in Bo＇ao,east of Hainan Island,which is one of the renowned beach resorts in China.In this research,the purpose is to reveal the erosion-accretion trends of Yudaisha beach in recent years.Based on 3S technologies,4 different years remote sensing image were selected,beach terrain was measured by GPS technology,then the evolution pattern of Yudaisha beach was analysed by GIS technology.The results indicated that distinct landward erosion had appeared in the coastline of Yudaisha beach from 1988 to 2005,the average landward erosion distance is 70m（4.1m/a） and the area reduced 35%.The coastal erosion was attributed to sea level rise and sediment load decrease of Wanquan river.With the impact of climate change and increasing the intensity of human activities,the Yudaisha beach is fragile,so we should pay close attention to it.