Fig. 1. Study area and sampling spots. Note: The left-hand section provides a sketch map of Guizhou province. The right-hand section provides an overview of the SAR data（R: 2018/06/09VV polarization，G:2018/06/21 VV polarization，B：2018/07/03 VV polarization）and geomorphic type （Ⅰ: Peak cluster depression, Ⅱ: Mound-peak platform, Ⅲ: Erosion platform, Ⅳ: Erosion steep slope, Ⅴ: Box canyon）and sample spots of the field survey

Fig. 2. Statistics maps of soil moisture for different acquisition dates

Fig. 3. Soil moisture maps for different acquisition dates

Fig. 4. Comparison between of measured and estimated soil moisture at time T4

Fig. 5. Data distribution maps of soil moisture measured, estimated values and error values in 47 measured plots