Wetland Landscape Changes of Daqing River Downstream in the Last 15 Years

摘要

Based on two sets of TM data and CBERS data ( acquired in 1993 and 2008, respectively ), and by means of the techniques of remote sensing (RS), geographical information system (GIS), and landscape ecology, this paper studied the dynamic development of wetland landscape patterns from 1993 to 2008 in Daqing River downstream. The results showed that as the intensity of human activities gradually strengthened in the past fifteen years, the integral structure of wetland types in this district had been varied greatly. The area and the patches number of the natural wetland decreased dramatically, while that of constructed wetland area increased incredibly. It was evident that the wetland landscape had transformed from natural to artificial. The change of each landscape index demonstrated that in the guidance of feedback information of hydrology and water resources availability and use risk, human economic activities not only directly changed the wetlands area but also changed the wetlands spatial pattern by the economic utilization of the wetlands in the past 15 years. The fragmentation degree aggravated and the wetlands went into a state of relatively uneven distribution, which further explained the spatial pattern that the area and the proportion of the natural wetlands reduced and the constructed wetlands tended to be dominant in Daqing River downstream.