关键词: 遥感, 地理信息系统, 陕甘宁青沙地, 宏观研究

Abstract: By using digital method of remote sensing and geographical information system techniques,TM images of 1996 and 2000 have been interpreted to establish the database of sandy land of the two periods in Ningxia Region.In the study,the definition of the sandy land is the land that is covered by sand and the vegetation coverage is lower than 5%,and it includes sand desert.There are as much as 313 498 km² sandy lands in Ningxia Region in 2000 and 24 811 km² less than that in 1996,the sandy land deceased by 7.334%.The percentage of sandy land area to the whole area decreased from 6.533% in 1996 to 6.054% in 2000,and decreased 0.120% each year.Further,the factors causing sandy land change were analyzed.The factors causing sandy land increasing are grassland desertification and cultivated land desertification,and they occupied 78.463% and 13.302%,respectively.The factors causing sandy land decreasing are that sandy lands were cultivated and planted grass,and they occupied 50.025% and 46.666% in order.

Key words: remote sensing technique, GIS, sandy land in Ningxia region, macro-scale study