1996年青海省沙漠现状及分布特征

PRESENT SITUATION AND DISTRIBUTING FEATURES OF THE SANDY LAND IN QINGHAI PROVINCE IN MID 1990S

以TM影象为信息源 ,在全数字方式下运用遥感技术与地理信息系统技术结合建立了青海省沙漠的TM图象数据库、图形数据库和属性数据库。通过对已建立的沙漠数据库的分析得出青海省沙漠广泛分布 ,土地沙漠化现象严重 ,全省有沙漠面积 44 31749hm2 ,占全省面积的 6 .184% ,在 45个县区级行政区域单元中 2 6个县市有沙漠分布。

Located in the southeastern part of Qinghai Xizang plateau, Qinghai Province has an average elevation of about 4,000 m a.s.l. Under the effect of different neotectonics, a geomorphological pattern of a basin in its central part and two high mountains in its south and north forms. West wind and northwest wind prevail over the province, and the days of sand starting wind stronger than 5m/s are over 150. Under the arid and semi arid climatic conditions, Quatenary deposit is distributed extensively, dry denudation and wind erosion are violent, desert and sandy land develop extensively, and Qinghai is one of the provinces with more sandy land. In this paper, the databases, including TM image database, graphical database and attributing database of sandy land in Qinghai Province in mid 1990s, are developed by using digited methods of remote sensing and geographical information system. The results show that the sandy land area in Qinghai Province was 4 431 749hm 2 in mid 1990s, which occupies 6.184% of the total area. Sandy land exists in 19 regional units among the 45 units in county level, and it is distributed in a large area in the source areas of the rivers. It is suggested to strengthen the monitoring and research of the developing tendency of desertification in these regions so as to provide the scientific basis for watershed reliagnment and water and soil conservation.