Ground, Proximal, and Satellite Remote Sensing of Soil Moisture

Abstract

Soil moisture (SM) is a key hydrologic state variable that is of significant importance for numerous Earth and environmental science applications that directly impact the global environment and human society. Potential applications include, but are not limited to, forecasting of weather and climate variability; prediction and monitoring of drought conditions; management and allocation of water resources; agricultural plant production and alleviation of famine; prevention of natural disasters such as wild fires, landslides, floods, and dust storms; or monitoring of ecosystem response to climate change. Because of the importance and wide‐ranging applicability of highly variable spatial and temporal SM information that links the water, energy, and carbon cycles, significant efforts and resources have been devoted in recent years to advance SM measurement and monitoring capabilities from the point to the global scales. This review encompasses recent advances and the state‐of‐the‐art of ground, proximal, and novel SM remote sensing techniques at various spatial and temporal scales and identifies critical future research needs and directions to further advance and optimize technology, analysis and retrieval methods, and the application of SM information to improve the understanding of critical zone moisture dynamics. Despite the impressive progress over the last decade, there are still many opportunities and needs to, for example, improve SM retrieval from remotely sensed optical, thermal, and microwave data and opportunities for novel applications of SM information for water resources management, sustainable environmental development, and food security.

Assessing the potential of soil moisture measurements for regional landslide early warning

“…Electromagnetic properties are measured (e.g. travel time, charge time) which can be related to the dielectric permittivity of the surrounding material (Babaeian et al 2019). The large dielectric permittivity differences between water (~80) and solids (~4) or air (1) allow then the estimation of VWC using a specific calibration function (Looyenga 1965;Topp et al 1980).…”

Linking Remote Sensing and Geodiversity and Their Traits Relevant to Biodiversity—Part I: Soil Characteristics

“…Soil moisture measurement techniques have been recently reviewed by Babaeian et al [50]. In general, there are two different approaches that use RS techniques to understand soil characteristics, their hydrological traits and eventually the spatial and temporal dynamics of soil moisture: (i) Direct measurements for areas where the soil has no or limited vegetation (using active and passive microwave sensors as well as optical RS data, Figure 7) and (ii) indirect measurements where vegetation covers the soil, using vegetation traits as a proxy of the soil and soil moisture traits.…”

Intertwining Observations and Predictions in Vadose Zone Hydrology: A Review of Selected Studies

“…When dealing with the onset of vegetation stress or rainfall-triggered landslides, one should determine the spatial and temporal fluctuations of soil moisture in the entire rooting zone, or even below it, and ground-based sensor techniques help tackle these problems more effectively. The present-day complex issues of irrigation water management or groundwater recharge require soil moisture monitoring by using an integrated array of ground-and satellite-based sensors, together with recently developed proximal sensing that includes UASs or stationary and rover cosmic-ray neutron probes (CRNPs) (e.g., [50]).…”