Seasonal and inter-annual features of ET
were analyzed over four periods. Normalization method was adopted to exclude the effects of potential evapotranspiration and soil water stress on ET
. During land degradation process, when natural vegetation (including leaves and branches), sand dunes, dry sand layers and BSCs were all bulldozed, ET
was observed to increase with a mild rate. In vegetation rehabilitation process with sufficient groundwater, ET
also increased with a faster rate.