Landscape pattern change of land use in the typical area of the Hanjiang River Basin

摘要

With remote sensing data and GIS, the classification system of land landscape in the typical area of the Hanjiang River Basin is established. Using the indexes of the landscape pattern index and the ecological value index (EVI),this article presents the dynamic change of the landscape pattern from 1986 to 2006. The results showed that: (1)There is a dramatic staggered change. From the year of 1986 to 1996, the absolute change extent obey the following sequence: no use land > forest land > build land > cultivated land> water > grassland; and from 1996 to 2006, no use land > build land > forest land > cultivated land> water > grassland. Over the past 20 years, no use land > build land > forest land > cultivated land> water > grassland.(2)The landscape of the Basin tended to become more fragmentized. From 1986 to 1996, the landscape of Hanjiang River Basin tended to become more fragmentized. The patches, in general, became smaller, more even, and less complex. The Ecological Value Index (EVI) of the whole catchment grown upon from 6661 to 6687. From 1996 to 2006, the catchment landscape became more fragmentized as before, and the amount of patches increased, and the average size of patches increased. The patches became more complex with Ecological Value Index rising from 6687 to 6783, as shows that the ecological situation of the catchment was being improved.