Land Use Change Affected by Policy of Returning Farmland to Forest and Grassland in Yinzhou Town,Mizhi County

Taking two composite Landsat 5 TM(thematic mapper)images in 1986 and 2006 and land use map of Yinzhou town,Mizhi County in 1996 as data resources,land use/land cover changes(LUCC)of Yinzhou from 1986 to 2006 are studied using the Geographical Information System(ArcGIS 9.0)and ERDAS(remote sensing software).Results show that great changes have taken place in land use/land cover in Yinzhou from 1986 to 2006.From 1986 to 1996,change of land use structure was characterized by increases in cropland and other land use types and on the contrary water area,by decreases in woodland and grassland.Cropland changed obviously and woodland and grassland were mainly converted into cropland.From 1996 to 2006,change of land use structure was characterized by increases in woodland and grassland increased.On the contrary,water area,cropland,and other land use types decreased.Cropland was mainly converted into woodland and grassland driven by the policy of returning farmland to forest and grassland.From 1986 to 2006,change of land use structure was characterized by increases in grassland and other land use types increased and on the contrary,by decreases in water area,cropland,and woodland.Water area,cropland,and woodland were mainly converted into grassland and other land use types.Land use change was mainly taken place in slope area and some croplands beside Wuding River were converted into other land use types.Although the ecological environment had been greatly improved in the area,it is still a long term task to protect and recover ecological environment by the policy of returning farmland to forest and grassland.