开都河流域下游绿洲景观格局变化分析

Analysis on the landscape pattern changes of the oasis in lower reaches of Kaidou river basin

以开都河下游绿洲为研究区,利用1990年、2000年、2011年三个不同时期遥感影像数据,运用RS与GIS技术,采用景观格局指数,分析开都河下游绿洲近30a的景观格局动态变化特征。研究结果表明:研究区景观多样性指数由1.41下降到1.39,优势度指数由0.13下降到0.03,景观破碎度指数由0.0034下降到0.0023,数值变化虽然不大,但均呈下降趋势,特别是破碎度指数只有0.0034、0.0024、0.0023,均接近于0,表明研究区景观破碎化程度相对较低,景观结构较为简单,异质性较低。从1990年以来,研究区的景观格局一直向破碎化与退化方向发展,其原因主要与土地利用类型的变化有关;虽然景观格局破碎化与退化的速度较慢,但是干旱荒漠地带绿洲生态系统的变化必须引起重视。

Taking the oasis in the lower reaches of Kaidou river basin as study area,using the satellite images of 1990,2000and 2011,the landscape pattern changes of the oasis were analyzed.The results showed that diversity index dropped from 1.41 to 1.39,dominance index decreased from 0.13 to 0.03,fragmentation index decreased from 0.0034 to 0.0023,although the changes scale was less,but showed a downward trend.The fragmentation indices were 0.0034,0.0024,0.0023 respectively,and the values were close to zero.The fragmentation degree was relatively low,the landscape structure was simple,and heterogeneity was low.Since 1990,the landscape pattern had been developing to fragmentation and degradation.It was mainly caused by land-use type＇s changes.Although the rates of fragmentation and degradation of landscape pattern were slow,but the changes of oasis ecological system of arid desert zone should be pay attention.