中文摘要：

在RS和GIS的支持下,采用1993年和2008年的2期Landsat TM影像为信息源,对乐清湾土地利用进行了生态风险变化研究。根据不同土地利用方式生态影响的空间分布和梯度变化,利用层次分析法确定了不同土地类型的生态风险权重,构建了一个综合性生态风险指数。通过对生态风险指数采样结果进行空间插值,分析解释了研究区的生态风险空间分布特征与形成机理。结果表明,乐清湾土地利用类型以林地为主,15年来建筑与交通用地、养殖区、旱地面积持续增大,而园地面积持续减小;由此导致相对高风险区域面积不断增大,低风险区域面积不断减小,使整个区域的生态风险指数整体增高,生态环境质量有所恶化。乐清湾湿地是急需采取保护性措施的重点区域。

英文摘要：

Based on RS and GIS,the temporal and spatial landscape changes of the wetland in Yueqing Bay were studied by using two periods of the Landsat TM,which were obtained in 1993 and 2008.Then the authors determine the weight values of the ecological risk from different land use patterns by analytic hierarchy process and construct integrated ecological risk index of different periods.The system sampling method was used to make it a spatial variable,the semivariagram analysis and block kriging were conducted to gain the spatial characteristics and inherent causes of regional ecological risk in the working area.The results indicate that the land use in Yueqing Bay is mainly the woodland,the area of cultivated land,construction and transportation land and saline land have been increasing continually,while the counterpart of garden land have been reducing with no stop,which lead to the rise of the high risk index area and the reduction of low risk index area,those made the ecological environment quality in Yueqing Bay deterioration.Yeuqing Bay wetland is the key areas urgent need some protective measures,the results provide the basis for regional land use and ecological environmental protection.