云南澜沧江流域景观格局时空动态研究

应用GIS技术和景观结构分析软件Fragstats3.3对云南澜沧江流域1985年、2000年的景观类型转化及其景观格局对比分析.结果表明,旱地、有林地、灌木林地、疏林地、高覆盖草地、中覆盖草地间的相互转化较频繁;在景观尺度上,区域景观破碎化程度下降,斑块形状变得较规则、简单,斑块的聚集度、连接性变好,景观多样性和均匀性增加;人类活动对景观格局的有利与不利影响,使各景观要素的结构与格局变化存在较大的差异性,其中,有林地、灌木林地、高覆盖草地的景观格局与区域景观变化相一致,而疏林地、中覆盖草地、水田、建设用地的景观格局与区域景观变化相反,旱田的景观格局变化较复杂;景观要素类型分布具有明显的垂直性,有80%的景观类型分布在海拔1 000～2 500 m之间,海拔2 500 m是澜沧江流域人类活动与该区景观类型的重要分界线,人类活动对澜沧江流域的干扰主要集中在中、低海拔地区.

Spatio-Temporal Dynamic Study on Landscape Patterns in Lancang River Watershed of Yunnan Province

Based on land use and land cover data,the landscape has been classified into twelve types,transition of landscape components and the changes of landscape patterns have been studied in Lancang river basin from 1985 to 2000 using GIS and Fragstats3.3.According to the results,the transition of the landscape was mainly happened among dry land,forest land,brush land,sparse woods,high-coverage grassland,middle-coverage grassland.At the landscape level,the fragmentation of landscape was decreased with a decrease in patch number from 44 054 to 44 978,the index of area-weighted fractal dimension and landscape shape index was decreased respectively,which leaded to the shape of patches more regular and simple.The other index of landscape was increased respectively,which leaded to the spatial aggregation and connectedness was improved,both the diversity and evenness of landscape were increasing.At patch level,the landscape components had a complex structural change and their pattern had a biggish difference due to man's advantaged and disadvantaged disturbance to landscape,the change trend of landscape pattern for forest land,bush forest and high-coverage grassland was consistent with that of regional landscape,however,the change trend of landscape pattern for sparse woods,middle-coverage grassland,paddy field and construction land was inconsistent with that of regional landscape,the dry land had a more complex structural change.The distribution of landscape components types has evident verticality and the landscape types about 80% distribute in elevation from 1 000 to 25 000 meter.The elevation 2500 meter is the important boundary for human activities and landscape types in this basin.The disturbance coming from human activities are focused on middle and low elevation.