关键词: 新生湿地, 黄河三角洲, 土地覆被, 时空模式, 演替过程, 图谱new-born wetland, the Yellow River Delta, land cover, tempo-spatial pattern, process of evolvement, Tupu

Abstract:

The new-born wetland in the Yellow River Delta (YRD) is located in the active river mouth in the east of the YRD, which is one of the separate parts of the Nature Reserve in YRD. From 1976 to 2000, as Yellow River water with high sediment content flowed over the flood plains, a progressing coastline and conspicuously changing land cover in this new-born wetland have occurred. Spatial and temporal landscape patterns resulting from interactions between natural conditions (e.g. vegetation, soil properties, and hydrology) and anthropogenic land use activities (e.g. agriculture, road construction and oil exploration) changed greatly during the last 20 years. Landscape is classified into 9 zones according to its different land covers in this region, i.e., sea in the study Bohai area, tidal flat, Seablite-Chinese tamarisk, Chinese aeluropus-Lalang grass, Common weed, Hankon willow and artificial forest, water bodies, agriculture area, and residence, road and oil field zone. They respectively stand for saline habitat, swamp habitat, neutral habitat and artificial habitat for different ecosystems. The archive of satellite data allows us to quantify land cover changes in the region over the past 20 years. Based on supervised classification by ERDAS with field survey and statistical data, fourtemporal land cover classifications were achieved by LandsatTM432,CBERS-1 CCD432 imager and vector data from atlas of the Yellow River Delta covering 1984, 1991, 1996 and 2000. Two ecological evolving series are concluded in those maps and intertwined with each other in the region, i.e., the wetland ecological evolvement and the saline ecological evolvement. Three evolving patterns of the zonal centroid of these 9 types of landscapes are summarized according to their different spatial distributions and temporal evolvement directions. One is the Land-evolving pattern, which is followed by tidal flats, common weed, water bodies, forested land, and Seablite. Another one is the Sea-backward pattern, which is followed by sea in the study area and Chinese aeluropus-Lalang grass. The third pattern is Human-resulting pattern, i.e., cultivated land and residence and industrial zone, which is mostly controlled by human beings in suitable living environment for productivities.

Key words: new-born wetland, the Yellow River Delta, land cover, tempo-spatial pattern, process of evolvement, Tupu