Based on SPOT-VGT NDVI and meteorological data from 1999to 2009

the paper synthesized monthly and yearly maximum NDVI

and standardized anomaly NDVI.Using some spatiotemporal analysis methods

such as regression analysis

correlation analysis and variation coefficient

the paper studied the dynamic characteristics of vegetation in Ningxia Hui Autonomous Region over recent 11years.The spatial distribution analysis results show that the NDVI values were higher in the north and the south part

but lower in middle.This characteristic agreed with the geographical division and vegetation distribution pattern of Ningxia.The NDVI values changed greatly over time and responded closely to yearly precipitation

especially in the drought zone located in the middle of the region.The NDVI in most places within the region increased during the period and in only five areas decreases of NDVI were found

which indicated the whole vegetation cover the region became better over the period.The spatiotemporal variations of NDVI show that the ecosystem has been gradually improved in recent years as the NDVI variations responded clearly to the ecosystem changes.There had some ecological restorations projects applied recently

which might be the major factor that resulted in the increase of NDVI in the region