清水河流域1978-2010年土地利用变化时空特征

通过对1978年、1998年和2010年3期遥感影像目视解译获得3期土地利用数据，分析清水河流域1978－2010年土地利用变化时空特征。研究表明：清水河流域1978－2010年期间，农用地、难利用地面积持续减少，林地、建设用地面积持续增加，草地面积先有所减少后增多，除林地以外其它土地类型变化幅度后期都较前期大；流域土地利用转移方向主要是农用地转为低、中、高覆盖度草地、林地和建设用地，中覆盖度草地转为低、高覆盖度草地和林地，低覆盖度草地转为中、高覆盖度草地、林地。结果表明，近年来清水河流域水土保持措施效果明显。

Spatial-temporal characteristics of land use changes in Qingshui River basin from 1978 to 2010

Land use data of three periods are interpreted from remote sensing images in 1978 ,1998 and 2010 ,and the spatial and temporal variation of land use in QingShui basin is analyzed .The results show that :(a) the area of arable and unused land keeps on decreasing ,while forest and construction land keeps on increasing .The area of grassland decreases firstly and then gradually increases .Except for the forest land ,the variation rates of all the other land use during 1998 - 2010 were higher than 1978 - 1998 .(a) From 1978 to 2010 , the directions of land use change in Qingshui basin have been mainly as follows :cultivated land mainly converts to low ,middle ,high coverage grassland ,forest and building land ;middle coverage grassland converts to low ,high coverage grassland and forest land ;and low coverage grassland converts to middle ,high coverage grassland ,forest and cultivated land .Results show the soil and water conservation in Qingshui Rive remains effective .