Abstract: To study the temporal and spatial change of vegetation ecological quality index in Shiyang river basin from 2000 to 2020, the MODIS NDVI remote sensing data, DEM data and land use classification map were used based on remote sensing and GIS technology by using transition matrix and linear regression model. And the distribution characteristics of vegetation ecological quality index under different altitude, slope, aspect and vegetation type were analyzed. Understanding the changes of vegetation ecological quality of Shiyang river basin could provide theoretical foundation and scientific bases for ecological protection and construction. The results showed that: (1) the average of the index from 2000 to 2020 was 9.8 and there existed a great gap between the south and the north in this area. There was a positive correlation between vegetation ecological quality index and altitude, slope. (2)The transition matrix of vegetation ecological quality index showed that the vegetation ecological quality was improved from 2000. The proportion of the area of the vegetation ecological quality improved and degraded on the total area were 30.0% and 2.2% from 2000 to 2010, and it were 13.7% and 10.9% from 2010 to 2020. (3)The vegetation ecological quality index was increased 1.2 every decade and the area of the index improved (slope>0.0) accounted for 90.3% of the total area from 2000 to 2020. (4)The area of the vegetation improved fluctuated with the increase of altitude. The area of the vegetation improved increased at first and then decreased with the increase of slope. (5)The proportion of the area in the forest, grassland and bush improved were all above 60.0%. (6)The correlation coefficient between vegetation ecological quality index and temperature and precipitation were 0.352 and 0.281 respectively and temperature was the key influence factor in Shiyang river basin.

Key words: Vegetation ecological quality index, Transition matrix, Linear regression model, Temporal and spatial change, Shiyang river basin