中文摘要：

海岛是一种相对独立的生态系统,正因为其独立性,一旦遭到自然灾害的袭击,海岛生态系统的景观结构就会发生改变,使得景观不稳定。而景观稳定性又表现为景观的抗性和恢复力。那么海岛景观受到破坏后恢复到稳定状态的恢复力就与海岛受自然灾害潜在风险程度有关。景观越稳定,那么其受自然灾害潜在风险程度就越小,反之,景观越不稳定,其受自然灾害潜在风险程度就越大。文中分析了景观稳定性与景观异质性、景观破碎度和景观镶嵌度的关系,以及与人工景观面积大小的关系。指出了海岛景观格局与海岛风险程度的关系,提出了基于景观格局的海岛自然灾害风险评价方法,并基于景观异质性指数、景观破碎化指数、景观镶嵌度指数和人工景观面积比等指数建立了海岛自然灾害风险评价模型。以长岛南五岛中的大黑山岛、北长山岛和南长山岛为研究区域,对文中提出的相对风险评价方法进行了应用,评价结果与传统的评价结果完全一致。

英文摘要：

Island is a relative independent ecosystem.Just because of its independence,once happening natural deserters,the landscape patterns of island ecosystem would change,which makes the landscape not be stable.Landscape stability shows fastness and resilience.So the resilience that island recovers to its original stable situation once it was destroyed is correlation with island risk degree.The more stable landscape is,the smaller risk degree is,and vice versa.The relation between landscape stability and landscape diversity,landscape fragile degree,landscape mosaic＇s spatial diversity and human disturbance degree is analyzed.The correlation of island landscape pattern with island risk degree is pointed.A risk assessment method of natural hazard for island based on landscapes patterns was presented.Based on landscape diversity index,landscape fragile index,landscape mosaic＇s spatial diversity index,and the proportion of manmade landscapes,a risk assessment model of natural disasters for islands is proposed.Daheishan Island,Beichangshan Island and Nanchangshan Island of Nanwu Island in China are chose for study areas,and the proposed risk assessment method in this paper is applied in the study areas.It shows that the assessment results using the proposed method were coincided with the traditional methods.