长江三角洲海岸侵蚀脆弱性模糊综合评价

FUZZY COMPREHENSIVE ASSESSMENT ON THE YANGTZE RIVER DELTA COASTAL EROSION VULNERABILITY

近年来,随着海平面上升以及入海泥沙减少等原因,长江三角洲地区面临海岸侵蚀威胁。建立了基于模糊方法的海岸侵蚀脆弱性评价模型,选取了海平面上升速率、地面下沉速率、平均高潮位、近海海水含沙量、潮滩坡度、潮滩宽度和海岸线变化等7个评价因子,对长三角8个具有代表性的海岸线岸段进行海岸侵蚀脆弱性(CVI)评价,并绘制评价结果图。结果表明长三角海岸侵蚀脆弱性分布有明显的区域差异,海岸侵蚀脆弱性评价结果与海岸侵蚀现状具有较大的相关性,说明选取的评价体系和基于模糊方法的CVI评价模型在长三角地区具有较好的适应性。最后根据评价结果预测,长三角海岸有向高脆弱性发展的趋势,在今后几十年内淤涨趋势将减缓,一些原本是高脆弱性的岸段的海岸侵蚀将加剧。

In recent years,with sea levels rising and sediment reducing,the Yangtze River Delta region is facing the threat of coastal erosion.This paper applied fuzzy comprehensive assessment method to evaluate the coastal erosion in the Yangtze River Delta.The assessment factors were sea-level rise rate,ground subsidence rate,average high tides,offshore sea water sediment,tidal slope,tidal width and coastal line change rate.8coastal segments in the Yangtze River Delta were selected as the object of study.It applied Fuzzy method and CVI model into studying the Yangtze River Delta Coastal Erosion vulnerability,combined with GIS and then depicted the coastal vulnerability map.The results showed that the Yangtze River Delta coastal vulnerability profiles revealed clear regional differences.And the CVI result had great relevance to the Costal erosion status in the Yangtze River Delta.It indicated that fuzzy comprehensive assessment of coastal vulnerability was an effective way to study the Yangtze River Delta coastal erosion risk.Finally,it predicted that the Yangtze River Delta coast had a trend to the high vulnerability in the next several years according to evaluation results.And the trend of silt up will be slower,while the erosion will be intensifier,and high vulnerability coastal sections will increase.