New horizons: remote sensing of soil moisture

• Autores: E. Soylu, D. Entekhabi, R.L. Bras
• Localización: Estudios en la zona no saturada del suelo. Vol. XVII , ZNS’25: Pamplona / Iruña, 29 al 31 de octubre de 2025 : trabajos presentados en las XVII Jornadas de Investigación en la Zona No Saturada del Suelo, Pamplona, 29 a 31 de octubre de 2025 / coord. por Miguel Ángel Campo Bescos, Rafael Giménez Díaz, 2025, ISBN 978-84-9769-422-3, págs. 13-17
• Idioma: inglés
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• Resumen

  • Since the launch of SMOS (2009) and SMAP (2015), L-band microwave remote sensing has enabled global observation of near-surface soil moisture, providing new opportunities to investigate hydrological processes in the vadose zone. This article presents three novel globalscale applications of SMAP data. First, shallow groundwater is detected by identifying characteristic patterns in surface soil moisture statistics and by training a machine learning model with one-dimensional numerical simulations of soil water dynamics. Second, irrigation is estimated by comparing observed SMAP soil moisture with model simulations and inferring the additional water input required to reproduce the observations. Third, a Gaussian Process Regression emulator, trained on Hydrus-1D simulations, is developed to estimate diffuse groundwater recharge using SMAP, GPM precipitation, and PET data as inputs. The resulting global recharge maps are consistent with GRACE and ERA5-derived products and highlight regions where SMAP effectively captures groundwater–surface interactions. Overall, the findings demonstrate the potential of L-band microwave remote sensing, in combination with numerical and statistical modeling, to provide valuable insights into soil–groundwater dynamics and global water use.