关键词: 改道, 黄河三角洲, 湿地, 景观格局

Abstract: Based on the 1995-1999 Landsat TM images and geographic information systems, this paper analyzed the change characteristics of wetland landscape pattern in the Eastern Yellow River Delta Nature Reserve (an inlet of current flow path emptying into the sea), and related driving factors during the past few years pre and post the Yellow River diverting into Qing 8 anabranches in 1996. In 1995-1999, natural wetland was still the matrix of the wetlands in the Reserve, while constructed wetland only had a very small proportion. A substantial increase was observed in the area of nonwetlands, and a decline was found in the area of natural and constructed wetlands, among which, bare muddy tidal flats and marshes shrank significantly. Though the landscape types in the reserve had no homogeneity in the changes of shape and structure, and their aggregation degree in spatial distribution varied, the overall landscape structure became more complicated and fragmented, and the distribution of inner landscape types converted from continuously large blocks to discretely small patches. River diversion, flow break, and human activities were the main three driving factors leading to the changes of the wetland landscape pattern in the reserve.

Key words: diversion, Yellow River Delta, wetland, landscape pattern