On the Composite Desertification and Its Temporal and Spatial Change——Taking the Aibinur Lake Region in Xinjiang as An Example

The study was conducted in the Aibinur lake region of Xinjiang.First,the monitoring index system and evaluating methods concerning desertification were analyzed,based on which the concept of composite desertification was defined.Then information about the current status as well as dynamic changes of various types of desertification in the study area was extracted from remote sensing images.The results showed: the area of desertification controlled by a single dominant factor accounted for 82.29% of the total desertification area,while that of composite desertification amounted to 17.71%;during 2002 and 2005,the surface area of Aibinur lake reduced by 322.507 3 km2,the total desertification area increased by 7.18%,and the composite desertification area increased by 133%.It was also demonstrated that,during the period,some change had happened to the general process of desertification in the area.The area of desertification caused by wind-erosion and composite means increased,while saltification induced desertification area declined.As a whole,the desertification area expanded in the region,and a trend could be clearly seen that the composite desertification was becoming increasingly important and diversified,and the place of it was extending from lands of brush and psammophytic forest to other lands.