Remote Sensing Monitoring of Forest Land Change in Hexi Corridor since Construction of the Three-North Shelterbelt Project

In order to assess the effect of the \!Three-North Shelterbelt Project in Hexi Corridor,we analyzed dynamic change of forest lands in Hexi Corridor based on Landsat data in 1978,1990,2000 and 2007 and GIS.Results showed that forest land area decreased at first and then increased during the 30 years.In detail,forest land area decreased significantly from 1978 to 1990,increased substantially from 1990 to 2000,and increased slowly from 2000 to 2007.In terms of spatial pattern,forest land area had a little change in mountain area while its change was not significant in plain area in Hexi Corridor.According to analysis on forest land transformation process,it was concluded that human factors were dominant driving factors in forest land area change in Hexi Corridor from1978 to 2007.