中文摘要：

通过使用ERDAS和GIS分析工具对陇东地区1978年、1990年、2000年和2007年4期遥感影像进行人工目视解译,得出近30年来陇东黄土高原沟壑区林地的动态变化信息.结果表明,近30年陇东黄土高原沟壑区林地面积总体上呈增加趋势,表现为1978—1990年林地面积减少,1990—2000年林地面积增加,2000—2007年林地面积大幅增加.对林地变化的驱动力分析表明,人类活动是影响林地变化的主要因素;此外,气候变化、虫害等因素对林地时空变化也产生了影响.

英文摘要：

Based on four remote sensing images（MSS in 1978 and TM in 1990,ETM＋ in 2000 and TM in 2006）,the spatial-temporal changes of woodlands in the Longdong loess plateau area are analyzed with the support of ERDAS and GIS.Over the past 30 years the total area of the woodlands increased,during 1978 to 1990,patchy forest decreased heavily,during 1990 to 2000,patchy forest increased,from 2000 to 2007,forest land was rising substantially.The process responsible for woodlands change in the Longdong loess plateau area could be divided into natural and anthropogenic groups by analyzing the transition matrices.Human activities have been an important factor,at the same time climate change and insect damage also play important roles.