论文
WANG Xiao-Qin, WANG Qin-Min, LI Hui-Guo, LIU Gao-Huan
Geomorphic type is one of the primary factors for the spatial pattern and the change speed of land use and land cover. Based on the land use and land cover data acquired in 1984, 1986, 1991, 1996 and 2001 of the Huanghe (Yellow) River delta, the land use and land cover changes were analyzed according to different micro-geomorphic types. There are six types of micro-geomorphic types in the river delta, which are terrace uplands, present flood plain, abandoned river courses, embanked former back swamps, isolated depressions and tidal flats. In the 17 years from 1984 to 2001, the proportion of unchanged land use and land cover was 30.04%. The largest unchanged land use was arable land, whose proportion to the all unchanged land use area was 57.49%; the second was tidal flat, whose proportion was 12.6%; the third was unused land, whose proportion was 10.57%; the fourth was residential area, whose proportion was 9.38%. The areas of unchanged land use and land cover from 1984 to 2001 were variable in different micro-geomorphic types. The unchanged land use and land cover lay mainly in embanked former back swamps. More than 50% of unchanged arable land, unused land and grass land were in embanked former back swamps. The change range and speed of land use and land cover were different in each micro-geomorphic type. In terrace uplands, the land use and land cover was most stable, the preponderant land use type was arable land, whose areas was about 80%. But its area decreases as a whole. In present flood plain, the land use and land cover types became more various, and land use and land cover changed most rapidly. In abandoned river courses, embanked former back swamps and isolated depressions, the area of changed land use/land covers was about 2/3, the dominating land use and land cover type was arable land, but the area continually decreased, which mainly changed to residential areas and water body. The areas of unused land and vegetable land cover changed only a little. In tidal flats, the tidal area decreased rapidly with the economic development. In 1984, the tidal area was 72.16%, but in 2001, there was only 36%. Most of the tidal area was developed to aquaculture area. The water body was 2 204 ha in 1984, 4 475 ha in 1991 and increased to 30 346 ha in 2001.
