Rs-based Landscape Dynamic Evolution in Areas of Cascade Hydropower Station Construction in the Upper Yellow River

With the increasing demand for energy sources, a further development hydropower energy resource will be an inevitable choice for China’s resource strategy. The cascade hydropower station construction produced serious impacts on the regional eco-environment. The most obvious characteristics of impacts caused by the cascade hydropower plant development are progressive, cumulative and regional, which can be described more clearly after applying remote sensing technology on its perspective of space-time. In this paper, the study of Yellow river section between longyangxia to Liujiaxia reservoir locates in the northwest inland plateau of China. The remote sensing data of 1977, 1996, 2000 and 2006 were selected to analyze regional landscape pattern evolution for hydropower cascade developments in last 30 years. The result indicates that the quality of regional ecosystem has been deteriorating since the1970s. The grass area has dropped from 8851.61 km in 1977 to 8228.86 km in 2006, in addition, the whole water area including rivers, reservoirs and bottomlands has expanded from 470.48 km in 1977 to 703.55 km in 2006. According to reviews of the regional landscape evolution, the Contagion Index presents a declining trend while the landscape diversity indexes rise, which implies that regional landscape patches turn to be more fragmented. The Landscape Shape Index of grass has increased from 40.07 in 1977 to 81.71 in 2006. This research demonstrates that regional land cover structures and landscape patches are evidently influenced by cascade hydropower exploitation. The remote sensing imagery information by Landsat series has been proved to be an effective means to manage and monitor the regional environment. * Corresponding author: Tel: 86-10-58807937; fax: 86-10-58807937; e-mail address: [email protected]. Foundation item: project 40771192 supported by National Nature Science Foundation of China