黄河源区玛曲县高寒湿地景观动态变化

Dynamic Changes of Alpine-Cold Wetland Landscape in Maqu County in the Yellow River Source Region

基于1994年、2001年和2008年3期Landsat TM遥感影像,应用斑块连接指数、分布质心和扩展度等景观格局指数,从景观水平上研究黄河源区玛曲县高寒湿地景观空间分布格局的动态变化过程。结果表明:玛曲县高寒湿地面积在研究时段内呈先减少后增加的变化趋势,1994—2001年,高寒湿地面积减少了0.78万hm2,2001—2008年增加了0.11万hm2;随着湿地面积的减小和斑块数量的增加,玛曲县高寒湿地斑块间隙越来越大,破碎化程度逐步加深;1994、2001、2008年玛曲高寒湿地的扩展度分别接近于1.96、2.12、1.99,斑块形状较为规则;1994—2008年,玛曲高寒湿地景观分布质心发生了明显的空间位移,湿地景观先向南偏移了0.02°,再向北、向西各偏移了0.01°。

Based on Landsat TM remote sensing data of 1994, 2001 and 2008, the dynamic change course of spatial distribution pattern of alpine-cold wetland landscape in Maqu County in the Yellow River source region was studied at landscape level by means of landscape pattern parameters including patch connectivity index, distribution centroid, and extension dimension etc. The results showed that the area of alpine-cold wetland in Maqu County was reduced by 7 800 hm2 from 1994 to 2001, but increased by 1 100 hm2 from 2001 to 2008. With the reduction of wetland area and the increment of wetland patch number, the gaps among alpine-cold wetland patches in Maqu County were enlarged, and the landscape fragmentation degree was gradually increased. The extension dimension of alpine-cold wetland in the studied region in 1994, 2001, and 2008 was close to 1.96, 2. 12, and 1.99 respective- ly, indicating the shape of wetland patches was relatively regular. The study also showed that the distribution een- troid of the alpine-cold wetland landscape in Maqu County significantly shifted toward south by 0.02°, and then shifted toward north and west respectively by 0.01 ° from 1994 to 2008.