Response analysis of land use change to the degree of human activities in Beiluo River basin since 1976

Land use change as an important factor reflects the degree of human activities. Analysis of spatial-temporal change of land use is an effective way to reveal the degree of land use change. Based on the remote sensing and GIS, the authors used man computer interactive image processing methods to acquire the land use data in 1976, 1998 and 2010, and analyzed the spatial-temporal variation of land use in Beiluo River basin from the rate of land use change, the direction of land use transformation, and the degree of land use. The results can be obtained as follows.(1) The integrated dynamic degree of land use increased from 0.61 during 1976-1998 to 6.66 during 1998-2010, the area of arable land and grassland decreased gradually, the rate was increased from 2.00% and 2.69% to 26.20% and 23.33% respectively, while the area of forest land and residential land increased gradually, the rate of the former increased from 5.93% during 1976-1998 to 59.68% during 1998-2010, and that of the latter decreased from 6.59% during 1976-1998 to 3.52% during 1998-2010.(2) The direction of land use change showed similar characteristics during the two periods. Forest land was converted from arable land and grassland, and a small part of residential land was converted from arable land.(3) The integrated degree of land use change ranged from-2-1 during 1976-1998 to-27-4 during 1998-2010. The authors proved that the impact of human activities on the natural environmental showed increasing trends, that arable land, grassland, forestland and residential land were mainly converted, that affected areas were mainly distributed in the upper basin, i.e., Wuqi county, Fuxian county, Ganquan county, Huangling county and Luochuan county, while the increasing area of forest land was much larger than the decreasing area of both arable land and grassland area, and the increasing area of residential land.