Chapter 15
Mapping and Monitoring of Soil Moisture,
Evapotranspiration, and Agricultural
Drought
Ali Levent Yagci and M. Tugrul Yilmaz
Abstract Soil moisture, evapotranspiration, and agricultural drought are so closely
interlinked phenomena that deficiency in soil moisture causes reduction in ET,
which eventually leads to vegetative stress and agricultural drought. Monitoring of
soil moisture, ET, and vegetation condition is indispensable to identify terrestrial
drought conditions to take proactive measures and mitigate its negative consequences. Although conventional methods such as the point-based measurements of
soil moisture, evapotranspiration, precipitation, and temperature records measured at
the ground stations (e.g., soil moisture networks, meteorological stations, and Eddy
covariance flux towers) provide accurate discreet observations, they are unable to
accurately capture the conditions in places between the ground stations. Therefore,
the techniques based on remote sensing inputs are important to track the spatially
continuous estimates of soil moisture, ET, and vegetation condition from the
regional to global scales, while the point-based estimates of soil moisture, ET,
precipitation, and temperature can be utilized to assist in validating satellite-based
estimates of soil moisture, ET, and agricultural drought. In this chapter, three distinct
proven methods to estimate soil moisture, ET, and agricultural drought using
satellite and ancillary data will be introduced, and then, some example maps and
their validation results against the ground truth will be presented.
Keywords Remote sensing · Soil moisture · Agricultural drought ·
Evapotranspiration · Hydrological model · ASCAT · SMOS · NOAH · MODIS ·
NDVI · LST · Trapezoid model · VCI
A. L. Yagci (*)
Department of Geomatics Engineering, Gebze Technical University, Gebze, Kocaeli, Turkey
e-mail: alyagci@gtu.edu.tr
M. T. Yilmaz
Water Resources Division, Civil Engineering Department, Middle East Technical University,
Ankara, Turkey
e-mail: tuyilmaz@metu.edu.tr
© Springer Nature Switzerland AG 2021
L. Di, B. Üstündağ (eds.), Agro-geoinformatics, Springer Remote Sensing/
Photogrammetry, https://doi.org/10.1007/978-3-030-66387-2_15
299
Mapping and Monitoring of Soil Moisture,
Evapotranspiration, and Agricultural
Drought
Ali Levent Yagci and M. Tugrul Yilmaz
Abstract Soil moisture, evapotranspiration, and agricultural drought are so closely
interlinked phenomena that deficiency in soil moisture causes reduction in ET,
which eventually leads to vegetative stress and agricultural drought. Monitoring of
soil moisture, ET, and vegetation condition is indispensable to identify terrestrial
drought conditions to take proactive measures and mitigate its negative consequences. Although conventional methods such as the point-based measurements of
soil moisture, evapotranspiration, precipitation, and temperature records measured at
the ground stations (e.g., soil moisture networks, meteorological stations, and Eddy
covariance flux towers) provide accurate discreet observations, they are unable to
accurately capture the conditions in places between the ground stations. Therefore,
the techniques based on remote sensing inputs are important to track the spatially
continuous estimates of soil moisture, ET, and vegetation condition from the
regional to global scales, while the point-based estimates of soil moisture, ET,
precipitation, and temperature can be utilized to assist in validating satellite-based
estimates of soil moisture, ET, and agricultural drought. In this chapter, three distinct
proven methods to estimate soil moisture, ET, and agricultural drought using
satellite and ancillary data will be introduced, and then, some example maps and
their validation results against the ground truth will be presented.
Keywords Remote sensing · Soil moisture · Agricultural drought ·
Evapotranspiration · Hydrological model · ASCAT · SMOS · NOAH · MODIS ·
NDVI · LST · Trapezoid model · VCI
A. L. Yagci (*)
Department of Geomatics Engineering, Gebze Technical University, Gebze, Kocaeli, Turkey
e-mail: alyagci@gtu.edu.tr
M. T. Yilmaz
Water Resources Division, Civil Engineering Department, Middle East Technical University,
Ankara, Turkey
e-mail: tuyilmaz@metu.edu.tr
© Springer Nature Switzerland AG 2021
L. Di, B. Üstündağ (eds.), Agro-geoinformatics, Springer Remote Sensing/
Photogrammetry, https://doi.org/10.1007/978-3-030-66387-2_15
299