Landscape pattern changes and transition tendency factors in Shiyang River basin

Remote sensing technology and landscape ecology principles were used for extracting landscape pattern information on land use in Shiyang River basin from 1987 to 2001,and patch type transition tendency factors were constructed based on landscape class transition probability matrix.Then,landscape pattern space-time evolution and landscape class transition tendency of Shiyang River basin were discussed.The results showed that the dominant pattern of land-use in Shiyang River basin was dry land,sandy land and bare land;dry land affected by human activities showed expansion tendency;the water area decreased by about 14.51 km~2 during 14 years,most of which was transformed into beach.Large patches of landscape pattern in this area increased due to the increasing of sandy land,saline soil land,etc.Shiyang River basin landscape structure gradually became simple and landscape heterogeneity decreased,but the declined trend of diversity index was slowed by positive ecological environment control.Through analysis of transition tendency factors,we found that towns,dry land and sandy land showed expansion tendency,while saline soil land showed a shrinking tendency