Improved Surface Soil Moisture Estimation Model in Semi-Arid Regions Using the Vegetation Red-Edge Band Sensitive to Plant Growth

Accurate description of surface soil moisture (SSM) in vegetation-covered areas is great significance to water resource management and drought monitoring. To remove the effect vegetation on SSM estimation, index obtained from Sentinel-2 (S2) was applied for content (VWC) estimation. The VWC model substituted into cloud (WCM), thus, estimation developed based WCM. methodology tested at Daxing, Beijing, Gu’an, Hebei, which training validation data were acquired by situ measurements. results can be described as follows: (1) For areas, Modified Chlorophyll Absorption Ratio Index (MCARI) B3, B4, B5 bands S2 most suitable removing influence estimation; (2) Compared Sentinel-1 (S1) vertical–horizontal (VH) polarization, vertical–vertical (VV) polarization more achieved higher accuracy; (3) could used estimate under crop cover with high accuracy, indicated correlation coefficients (R2) between measured estimated 0.867, root mean square error (RMSE) 0.028 cm3/cm3, MAE 0.023 cm3/cm3. Thus, this has potential vegetated areas.