基于遥感的喀斯特地区水体景观格局演化定量分析

Study on Evolution and Quantitative Analysis of Water Landscape Patterns in Karst Region Based on Remote Sensing

关键词:  喀斯特地区  水体  遥感  景观格局  演化  定量分析

Key words:  karst area  water  remote sensing  landscape pattern  evolution  quantitative analysis

摘要:

选择广西隆安县为研究区，以年度内不同季节的LANDSAT 8 OLI遥感影像为数据来源，在遥感软件支持下，使用监督分类方法对研究区水体进行提取，进而采用空间分析方法得到不同季节间水体空间分布变化量，再采用Fragstats软件对水资源空间分布和季节间变化的景观格局特征进行分析。结果表明：从5月到8月，再从8月到11月，斑块面积（AREA）、斑块个数（NP）、斑块密度（PD）、景观形状指数（LSI）、景观分裂指数（DIVISION）等5个景观指数先上升后降低，最大斑块面积占比（LPI）、蔓延度指数（CONTAG）、斑块集聚度指数（AI）等3个指数先下降后上升，体现了喀斯特地区水体空间格局一年内呈现聚集度先升后降，蔓延度指数先降后升的趋势，水体空间格局的景观指数受季节影响较大；典型相关分析表明，斑块个数（NP）和斑块密度（PD）等基本景观指数与景观形状指数（LSI）、斑块集聚度指数（AI）、景观分裂指数（DIVISION）等存在高度相关，典型变量的极显著相关主要由斑块个数（NP）、斑块密度（PD）、景观形状指数（LSI）和斑块集聚度（AI）引起，但景观形状指（LSI）、蔓延度指数（CONTAG）、斑块集聚度指数（AI）等3个指标在演变过程中也存在一定波动和无序化，反映出喀斯特地区水体空间格局在不同季节间的变化，呈现出不规则和无序化的特征。

Abstract:

In this paper,Long'an County in Guangxi was selected as the research area,and the LANDSAT 8 OLI remote sensing images of different seasons within the year were used as data sources.With the support of remote sensing software,the water body in the study area was extracted by supervised classification method,and the spatial distribution variation of water in different seasons was obtained by spatial analysis method,and then the landscape pattern characteristics of the spatial distribution and seasonal variation of water resources were analyzed by Fragstats software.The results showed that from May to August,and then from August to November,five landscape indexes such as patch area (AREA),patch number (NP),patch density (PD),landscape shape index (LSI),landscape splitting index (DIVISION) first increased and then decreased,while three indexes such as maximum patch area ratio (LPI),contagion index (CONTAG) and patch aggregation index (AI) first decreased and then decreased.These phenomena reflected that the spatial pattern of water in karst area showed a trend of first increasing and then decreasing in aggregation degree and first decreasing and then rising in spread index.The landscape index of the spatial pattern of water bodies was greatly influenced by the seasons. Typical correlation analysis showed that the basic landscape indexes such as patch number (NP) and patch density (PD) were highly correlated with landscape shape index (LSI),patch aggregation index (AI) and landscape splitting index (DIVISION).The extremely significant correlation of typical variables was mainly caused by patch number (NP),patch density (PD),landscape shape index (LSI),and patch aggregation index (AI).However,landscape shape index (LSI),contagion index (CONTAG) and patch agglomeration index (AI) also had some fluctuations and disorder during the evolution process,reflecting the changes in the spatial pattern of water bodies in karst area between different seasons,showing irregular and disordered characteristics.