Evolution of NDVI and analysis of its correlation with influencing factors in desert-oasis transition zone
The desert-oasis transition zone,as the ecotone between desert and oasis,is the most active area in the mutual transformation process of oasis and desert,and has important ecological functions such as preventing desert expansion and maintaining oasis ecological security.Taking Minqin Basin as the research area,the Normal-ized difference vegetation index(NDVI)between oasis and desert was used to determine the range of desert-oasis transition zone in Minqin.Then,using the maximum NDVI data from 2000 to 2020 and the influencing factors such as precipitation,temperature,sunshine hours and soil moisture,partial correlation and multiple correlation analy-sis methods were used at pixel scale to study the trend of NDVI change and correlation analysis of influencing fac-tors.The results show that the 5000 m area outside the oasis boundary is the Minqin desert-oasis transition zone,in which the 0-300 m area outside the oasis is the core area of the transition zone,the 3000-2000 m area is the e-cotone area,and the 2000-5000 m area is the buffer zone.Since 2000,NDVI in the transition zone has shown an overall increasing trend,among which the areas with obvious improvement and stability account for a relatively high proportion(47.8％and 42.2％,respectively),while the other areas account for a relatively small proportion.The severely degraded areas are mainly in the core area of the transition zone near the oasis.The increase of precipitati-on plays a leading role in the improvement of zonal vegetation in the southern part of the transition zone,the in-crease of temperature plays a more significant role in the improvement of NDVI in the eastern and northwestern parts of the transition zone,the increase of sunshine hours plays a greater role in the improvement of NDVI in the western and southeastern parts of the transition zone,and the increase of soil moisture can promote the improvement of NDVI in the transition zone.Soil moisture and precipitation are the main factors to improve NDVI in transition zone.
万方数据
维普
