基于HY-1C的红海滩翅碱蓬提取与近5年变化趋势研究

A study on the extraction of Red Beach Suaeda salsa and its change trends in recent 5 years based on HY-1C data

为掌握红海滩翅碱蓬(Suaeda salsa)群落分布现状及修复情况,本文采用2018-2022年HY-1C卫星海岸带成像仪(CZI)数据,基于现场实测光谱特征分析,构建翅碱蓬遥感提取模型,获得了5期翅碱蓬群落空间分布数据,提取精度优于87%;基于提取结果,开展了红海滩翅碱蓬群落时空分布及类型水平上景观格局的变化分析,结果显示:近5年来,翅碱蓬群落分布面积总体呈显著增加趋势,斑块类型面积(CA)、斑块所占景观面积比例(PLAND)、最大斑块指数(LPI)、有效网格大小(MESH)、平均斑块面积(AREA_MN)等指标呈先减小后上升趋势,破碎化指数(SPLIT)先增大后减小、聚集指数(AI)总体呈上升趋势,可见翅碱蓬群落在红海滩景观构成中占比逐年增大,景观形状复杂度提升,破碎化势头得到逆转,聚集性分布趋势较为明显,这说明自2019年开始实施的翅碱蓬规模化修复工程成效显著;另一方面,翅碱蓬群落生境在总体持续向好的同时又表现出恢复水平空间不均衡的特点,大致为中、东部好于西部,南部好于北部。本文结果可为修复工程的效果评估工作提供基础数据,并为今后修复施工的空间布局规划提供决策参考。

In order to master the current distribution and the restoration status of Suaeda salsa in the Red Beach,a remote sensing extraction model was constructed based on the HY-1C satellite CZI data and on-site measured spec-tral.Five periods of spatial distribution data of S.salsa were obtained in 2018-2022,with the extraction accuracy better than 87%;based on the extracted results,a change analysis on the spatio-temporal distribution and the class-level landscape pattern of S.salsa was conducted.The results show that:in the past 5 years,the overall distribution area of the S.salsa community has shown a significant increase trend,with indicators such as class area(CA),per-centage of landscape(PLAND),largest patch index(LPI),effective mesh size(MESH),and mean patch size(AREA_MN)showing a first decreasing and then increasing trend,splitting index(SPLIT)first increasing and then decreasing,and aggregation index(AI)overall showing an upward trend.It can be seen that the proportion of S.salsa community in the landscape composition of Red Beach has been increasing year by year,the complexity of landscape shape has increased,the fragmentation trend has been reversed,and the trend of aggregation distribution is more obvious.This all indicates that the large-scale restoration project of S.salsa implemented since 2019 has achieved a significant result.The biotope of the Red Beach S.salsa continues to improve,but at the same time,it shows a spatial imbalance of the recovery level,which is generally better in the middle and east than in the west,and better in the south than in the north.The results of this paper can provide basic data for the evaluation of the ef-fectiveness of the restoration project,and provide decision-making reference for the spatial planning in the future restoration work.