雅砻江流域湿地景观格局变化分析

CHANGES OF WETLAND LANDSCAPES IN THE YALONG RIVER CATCHMENT

应用ArcGIS软件,对雅砻江流域湿地1986和2000年遥感数据进行解译、矢量化处理,用Apack软件进行湿地景观格局指数计算,研究了近15a雅砻江流域景观空间格局特征及其变化。结果表明:(1)近15a雅砻江流域湿地景观面积减少,减少量为494.04hm2,占2000年湿地总面积的0.506%;(2)两个时期内湿地斑块密度保持不变,湿地景观的聚集度都很高,均在0.99以上,湿地景观集中分布,破碎化水平低;(3)雅砻江流域湿地景观的多样性指数水平和均匀度水平较低,而且两指数在两个个时期内没有发生太大的变化,且各类湿地景观比例差异相对较大,沼泽湿地景观控制的程度较高;(4)雅砻江流域的5类湿地景观分布质心基本上未发生变化,但总体格局分布质心向南偏移0.01°,再向西偏移0.23°,整体上向西南方向偏移了25.32km。

Based on the interpretation and vector processing of remote sensing images of 1986 and 2000,the index of wetland landscape pattern was calculated by using Apack software,and the spatial pattern of wetland landscape in the Yalong River catchment was studied based on Geographical Information System during the period from 1986 to 2000.Results showed that:(1) In the last 15 years,the wetland area in the Yalong River catchment decreased 494.04 hm2,which was 0.506% of wetland landscape area in 2000;(2) During the two periods,the patch density of wetland landscape in the Yalong River catchment was kept stable,the convergence index were all above 0.99,and wetland landscape showed the characteristics of concentrated distribution and low fragment;(3) The diversity index and Evenness index in the Yalong River catchment were low,and changed a little,there was a great proportional difference among the five wetland landscapes and marsh wetland was the dominant wetland landscape;(4) In the Yalong River catchment,the centroid distribution of the whole wetland landscape moved 0.01° to the south and then 0.23° to the west,moving 25.32 km southwest.