浙西低山丘陵区景观格局变化的高程分异研究——以桐庐县为例

国内外学者对于景观格局的地形分异研究,经历了从景观类型分布高程差异到景观指数高程分异研究的过程,目前处在景观格局静态地形分异阶段。本文利用浙江西部桐庐县1996、2004的土地利用现状图和DEM数据,对其1996-2004年景观格局动态演变特征的高程分异规律进行研究。研究对桐庐县1996、2004年的土地利用现状图进行处理获得景观类型分布图,通过1∶10000的DEM数据的分带操作,生成不同高程带的景观类型分布图。选取斑块密度、景观形状指数、分维数、破碎度、香农多样性指数、香农均匀度指数等景观格局指数,并在ArcGIS和Fragstats的支持下,计算出各带两个年份的景观格局指数并作对比分析。结果表明:研究区景观格局演变具有明显的高程分异特征,不仅表现为景观类型分布的变化与高程变化相关,而且体现在景观格局指数的变化值随高程上升而增减的趋势也有一定的规律性:景观水平上所有指数变化的剧烈程度大致与高程呈负相关关系,景观类型水平上各景观类型的破碎度、和斑块密度变化程度随海拔升高趋于缓和。

Study on variation of landscape pattern changes with elevation in hilly area of western zhejiang-a case study in Tonglu county

Terrain,especially the elevation,is an important element which influences the Landscape pattern in a long time period.This article studied the variation of the evolvement of landscape pattern character in Tonglu between 1996 and 2004 to the change of elevation based on the landscape ecology theory.The landscape pattern maps of 1996 and 2004 were compiled with the assistant of land use map.After plotting out the DEM data,six elevation zones were created,and then six pair of corresponding landscape pattern maps got prepared.Patch Density,Landscape Shape Index,Fractal Index,Fragmentation,Shannon Diversity Index,Shannon Evenness Index were picked out and input the landscape pattern maps into Fragstats 3.3 to make some landscape index calculation.The study result indicated that the evolvement of landscape pattern in Tonglu was affected by elevation distinctly.Not only the distribution change of several landscape types but also the change of several landscape pattern indexes in both landscape level and class level varied from different elevation zones;in landscape level the acuity of all the indexes change approximately had negative correlation with elevation;in landscape class level the change of Patch Density and Fragmentation was mitigated along with the increase of the altitude.