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

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 7800hm2 from 1994 to 2001, but increased by 1100hm2 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 respectively, indicating the shape of wetland patches was relatively regular. The study also showed that the distribution centroid 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.