Remote sensing-based temporal-spatial variability of desertification and driving forces in an agropastoral transitional zone of Northern Shaanxi Province, China

Abstract

Desertification has been widely treated as one of the major environmental hazards in the world by scientific
communities and the public. In order to assess temporal-spatial variability of desertification from 1986 through
1993 to 2003 in an agro-pastoral transitional zone of northern Shaanxi, China, satellite images were interpreted
and analyzed along with meteorological and socio-economic data. During the intervening 17-year period,
desertification has decreased in severity and increased in extent. Temporally, severe desertification has
decreased in area by 26.8% from 1986 to 2003. Desertification landscape patch quantities and fragmentation
indexes have increased gradually. Spatially, desertification has increased in extent north of the Great Wall and
decreased in extent in the Wudao river valley and north-western Shenmu County. The geographic centers of
deserts in the study area have moved to the south-west and north-east. Climate change and human activities were
somewhat responsible for the decrease in desertification severity but significantly affected the increase in
desertification extent. The “Three north shelterbelt program” and “grain-for-green project” carried out by the
governments were the dominant contributors to the desertification severity reversal. Desertification control is a
difficult and gradually process and the government should continue to play a leading role in this process.