In order to study the spatial and temporal evolution of the regional landscape in Hanjiang River in Shaanxi Province after the construction of hydropower system

remote sensing images of 1988

2000 and 2007 were interpreted and GIS buffer analysis was applied with widths of 500

1 000 and 5 000 m.The results indicated that water areas showed an increasing trend

while the arable land displayed a steady decreasing trend in the study area since 1988.During the sudied period

landscape pattern was in an unbalanced state with frequent two-way conversions

towards the direction that is beneficial for improving the regional ecology.According to the analysis on landscape fragmentation

landscape diversity and landscape shapes

the degree of landscape fragmentation pattern of the study area increased between 1988 and 2000

and the shape became more complex and landscapes was diversified.Between 2000 and 2007

the degree of landscape fragmentation reduced

the shape became more regular and the landscape diversity decreased.These evidences indicated that the landscape pattern experienced a regional ecological improvement.It can be concluded that the hydropower development has exerted great influences on the landscapes in the study area.