1987-2015年七里海潟湖湿地景观格局变化及驱动力分析

Wetland Landscape Pattern Changes and Driving Forces in Qilihai Lagoon,1987-2015

基于1987年、1994年、2001年、2005年、2010年和2015年的遥感数据,运用景观生态学原理,借助遥感和GIS技术,利用转移矩阵法、湿地动态度和景观格局指数等方法对1987-2015年七里海潟湖湿地景观格局变化进行分析,并利用主成分分析法对驱动力进行研究。结果表明,1987-2001年七里海潟湖湿地总面积持续增加,增加至2 113.64hm2,之后到2015年呈减小趋势,减少至2 016.97hm2;其中自然湿地面积至2015年减少了1 240.03hm2逐渐减少到436.66hm2,减少了74.0%。人工湿地面积比重由13.83%上升至67.92%,面积增加到1 580.30hm2。大面积的自然湿地转化为稻田和海水养殖场,各景观的百分比变化较大,景观多样性和均匀度降低,蔓延度增大,破碎度指数从0.005增加至0.012,表明景观异质性降低,形状趋于复杂化。社会经济和人口因素是稻田和海水养殖场规模扩大、自然湿地转化为人工湿地的主要驱动力。七里海潟湖湿地景观格局变化及驱动力分析可为湿地恢复与重建、自然保护区生物多样性提高提供理论基础与技术支撑。

Wetlands are critically important for climate regulaton and of great siginficance in both regional and global chimate change.Lagoons are an important type of ocean wetland and have been decreasing in area,drawing attention of many scholars.Based on remote sensing data of 1987,1994,2001,2005,2010 and 2015,landscape pattern changes and the driving forces in Qilihai lagoon were analyzed using a wetland conversion matrix,dynamic change of wetland,landscape pattern index,principal component analysis with the help of landscape ecology theory,remote sensing and GIS.The total wetland area of Qilihai lagoon increased from 1987 to 2001 and then decreased from 2001 to 2015.Natural wetlands have been converted to paddies and marine farms,altering the landscape pattern.The area of natural wetland has gradually decreased to 436.66 hm2,with a 74%reduction,while the proportion of artificial wetland area has increased to 1580.30 hm2,from 13.83%to 67.92% of the total wetland.Fragmentation has increased while landscape diversity index,evenness index and the landscape heterogeneity have decreased.The landscape pattern was complex as natural wetlands are converted and replaced by constructed wetlands,induced by socioeconomic development and population growth.The results provide a scientific basis for environmental protection and sustainable development in the Qilihai region.