县域尺度下不同时序茶园景观格局指数的粒度效应分析

Analysis of the Granularity Effect of Tea Garden Landscape Index in Different Time Series at County Scale

【目的】研究县域尺度下不同时序茶园景观格局指数的粒度效应及适宜粒度范围对揭示茶园景观格局变化及驱动机制具有重要意义。【方法】基于2002—2018年雅安市名山区土地利用现状调查数据,从斑块类型水平分析景观格局指数在10~300 m内的粒度效应确定适宜粒度范围,结合景观面积损失模型确定雅安市名山区茶园景观演变的最佳粒度。【结果】不同景观指数均表现出一定的尺度依赖性,对粒度变化存在高敏感度、中敏感度和低敏感度;景观指数随粒度增加包括单调递减、单调递增及复杂变化3种类型;茶园景观随粒度增加形状趋于规则化,景观空间破碎度和连接度随粒度增加而降低,但同一粒度下景观空间连接度和集聚度随时间增加有所提升。【结论】不同景观指数粒度效应不同,综合景观结构稳定性和信息损失度,确定雅安市名山区茶园景观的适宜分析粒度域为60~110 m,最佳空间粒度为60 m。

【Objective】Studying the granularity effect of tea garden landscape indexes in different time series at the county scale and analyzing the appropriate granularity range of the tea garden landscape pattern at the county scale are of great significance to reveal the change and driving mechanism of the tea garden landscape pattern.【Method】Based on the survey data of land use status in Mingshan District from 2002 to 2018,the granularity effect of landscape pattern index within 10-300 m is analyzed from the patch type level,determine the appropriate particle size range,combined with the landscape area loss model to determine the best particle size of the tea garden landscape evolution in Mingshan District.【Result】According to the different responsiveness of each index to granularity changes,it can be divided into three categories:high sensitivity,medium sensitivity and low sensitivity;according to the granularity effect curve,the above-mentioned landscape index can be roughly divided into three types:with the increase of granularity,the landscape index includes three types:monotonous decreasing,monotonous increasing and complex changes;the shape of the tea garden landscape tends to be regular with the increase of the grain size,the spatial fragmentation and connection degree decrease,and the distribution tends to be scattered,the spatial connectivity and agglomeration have increased as time goes by.【Conclusion】According to the research results,the granularity effect of different landscape indexes is different,considering the stability of the landscape structure and the accuracy of information loss,it is determined that the suitable analysis granularity range of Mingshan tea garden landscape is 60-110 m,and the optimal spatial granularity is 60 m.