关键词: 坝上后山地区, 人畜压力, 沙漠化景观界线, 互动

Abstract: In the paper,approach is made to the interaction between boundaries of degradation land and the pressure on land in spatial movements in the Houshan area of Bashang since liberation.Pressure on land for population and husbandry changes in almost the same way which grows all the area,but higher to the north,especially in the northeast part during 1950-1996.The creeping of pressure lines displays differently,from 1950-1980 lines in area of Houshan move north and get back since 1980,only that in Bashang pushes northeast continuously during 1950-1996.In the response,land degradation severity aggravates through the area,light degree of desertified land decreases,moderate degree line of > 20% moves towards southeast by 45 km.The types of different severity degrees that distributed separately in the 1970's link together from west to east,forming an axis of severity degree in the 1980's.In the desertified landscape,farmland experiencing wind erosion of > 30% develops rapidly moves northward by 30 km,pebble line of > 30% swifts south and west in large scale,but the sandy line pushes south a little and remains unchanged in the east.Getting lower in speed even withdraw in movements for pressure line reveals the regulation of population capacity by land degradation since 1980's.

Key words: Houshan area of Bashang, population and livestock pressure, desertified landscape, interaction