Satellite remote sensing analysis to monitor revegetation in the Yangtze
River Basin, China
Abstract
Revegetation programs aim to avoid land degradation, control soil
erosion, reduce floods, and improve ecological conditions. China has
planted billions of trees over the past 20 years. However, little is
known about the effectiveness of this artificial revegetation, and its
consequences on China’s national conservation policies and changes in
biophysical factors at the county level. Here we use satellite time
series data and develop a new metric, the revegetation index (RVI), that
quickly monitors revegetation and its long-term changes. We found that
the amount of regions where the Grain to Green Program (GTGP)
successfully was implemented only about 55.8% of the areas of GTGP
implementation. Surprisingly, we provide observational evidence that the
implementation of the GTGP can decrease soil erosion and drought, and
increase water availability, but revegetation in the Yangtze River Basin
(YRB) in China has a limited impact on soil erosion, water and drought.
In particular, for revegetation between 1999 and 2016, indicating that
previous an assessment by the government revealed as official statistics
may have overestimated the effects of the ecological restoration
practices.