乌兰布和沙漠风沙入黄段植被覆盖动态变化特征及驱动力

Based on the Landsat imagery data from 2001 to 2021,the NDVI and the image dichotomous model were used to estimate vegetation cover and explore the spatial and temporal trends and driving forces of vegetation cover in Ulan Buhe Desert along the Yellow River,in the hope of providing a theoretical basis for the restoration of vegetation in Ulan Buhe Desert along the Yellow River and the selection of key areas for future ecological construction.The results show that:(1)the overall vegetation cover in the study area showed a fluctuating upward trend,and the vegetation restoration status was good.The average vegetation cover increasing from 0.294 to 0.526,and the increase was most obvious from 2007 to 2017.(2)From 2001 to 2021,the transfer of vegetation cover between different levels in Ulan Buhe Desert along the Yellow River is more frequent,in which low vegetation cover and lower vegetation cover were transferred out to medium vegetation cover and higher vegetation cover in a large area of 102.00 km2 and 128.82 km2,respectively.In addition,42.1%of the area in the study area tends to increase significantly,mainly in the near Dengkou section,and 4.90%of the area tends to decrease significantly,mostly in the near Wuhai section,which should be the key area of concern in future ecological restoration.(3)The spatial variability of vegetation cover in this area is mainly driven by human activities,land use type changes and climate factors,and the interaction between the driving factors is mainly enhanced by two factors,among which,the key interaction factors with the highest degree of influence are land use type and annual average temperature(0.435).