Research of Changes in Cultivated Land in Xinjiang Based on RS and GIS

With the data of cultivated land in Xinjiang during 1990-2008 extracted from the land use data base and remote sensing images by means of spatial analyst in GIS,this paper analyzed its present temporal-spatial patterns,area changes and type structures,and its development dynamics.The results showed that the total area of cultivated land kept increasing,the annual average net-increased and reclamation speed increased sharply during 1990 and 2005 and then decreased slightly during 2005 and 2008,while the annual average loss speed kept decreasing.The reclamation of cultivated land extended from oases to deserts and gobi deserts,while the loss of cultivated land mainly occurred in oases.At the same time,the cultivated-land change in the mid-east,northwest and northeast border districts was relatively greater(Rid1.02).The reclama-tion transferred from grassland and forest land to grassland and non-utilized land,the ratio of non-utilized land reclamation continuously increased and the reclamation transferred from bare land and saline-alkali land to sandy lands,gobi deserts and saline-alkali land,while the utilization type of transformed cultivated land was mainly grassland,non-utilized land and construction land.The transformation between cultivated land and construction land was always negative,while the transformation between cultivated land and grassland was positive.