七里海湿地景观变化和生态韧性评价

Landscape Changes and Ecological Resilience Evaluation of QilihaiWetland

以2005年、2009年、2013年、2017年和2021年的Landsat影像为数据源,得到5个时期天津市七里海湿地各种土地利用类型的面积、分布和变化;以2005年七里海湿地的景观为本底景观,利用景观指数,分析景观变化规律;利用生态系统韧性评估模型,评价七里海湿地的生态韧性水平及其空间变化。研究结果表明,湿地的总面积从2005年的86.0031 km^(2)略微增加到2021年的86.1048 km^(2);与2005年相比,2021年,耕地/林地/绿地类型的面积增加了1.7757 km^(2),建筑用地和未利用地的面积分别减少了0.4437 km^(2)和1.4337 km^(2);5个时期,永久性河流和淡水湖的面积总体上都在小幅波动增大,草本沼泽和坑塘的面积明显减小,运河/输水河和水产养殖池的面积明显增大,耕地/林地/绿地类型的合计面积在小幅增大,建筑用地面积呈单峰型变化,未利用地的面积逐渐减小;随着时间的推移,七里海湿地东南部的景观趋于破碎化,景观多样性水平在提高,七里海湿地东北部的景观相对稳定;5个时期,东、西七里海南边缘和东七里海局部以及潮白河区域的生态韧性水平达到较高和高水平。

The Landsat images in 2005,2009,2013,2017 and 2021 were used as data sources.The area,distribution and change of various land use types were obtained in 5 periods in Qilihai wetland,Tianjin city.Taking Qilihai wetland landscape in 2005 as the background landscape,landscape change law was analyzed using landscape index.The ecological resilience level and its spatial change of Qilihai wetland were evaluated using the ecosystem resilience assessment model.The results showed that the total area of the wetlands increased slightly from 86.0031 km2 in 2005 to 86.1048 km2 in 2021.Compared with those in 2005,the areas of cultivated land,forest land and green land increased by 1.7757 km2,and the areas of building land and unused land decreased by 0.4437 km2 and 1.4337 km2 respectively in 2021.In 5 periods,the areas of permanent rivers and freshwater lakes increased with small fluctuations.The areas of herbaceous marshes and ponds decreased significantly.The area of canals/water conveyances and aquaculture ponds increased significantly.The areas of cultivated land,forest land and green land increased slightly.The area of building land showed unimodal change.The area of unused land decreased gradually.With the passage of time,the landscape in the southeast of Qilihai wetland tended to be fragmented,the level of landscape diversity was increasing,and the landscape in the northeast of Qilihai wetland was relatively stable.In 5 periods,the ecological resilience of the southern edge of the east and west Qilihai,parts of the east Qilihai,and the Chaobai River region,reached higher and higher levels.