The images of Naimanqi in the year 1975

1985

1995

and 2005 were interpreted and the land use change in typical area of Horqin sand land during recent 30 years was analyzed by using 3S technology.Results showed that the area of landscape types of sandy land was reduced obviously.The reduced extent of fixed dune was significant

decreasing from 44.79% in 1975 to 6.18% in 2005.The areas of cultivated land and woodland increased prominently

especially the woodland with the net increase of 29.72%.The areas of other landscape types did not change obviously.The transfers among the main land use types were from mobile dune and semi-fixed dune to fixed dune

cultivated land

and woodland;from fixed dune and pasture to cultivated land and woodland;from cultivated land to woodland;and from woodland to cultivated land.In view of the change space pattern

the number of woodland patches was the most

being 191 in 2005.The index of the largest patch of cultivated land was the greatest and its numerical value was 43.12 in 2005.The mean patch area of fixed dune was more than other landscape types

being 1 896.50 hm2 in 2005.The connect index was reduced continually from 2.62 in 1975 to 2.13 in 2005.However

the patch density(PD) index changed oppositely

increasing continually from 0.15 in 1975 to 0.44 in 2005.The Shaanon's diversity index(SHDI) and Shannon's evenness index(SHEI) presented the similar changing trend of increasing first and then decreasing.