A physically based approach for the estimation of root-zone soil moisture from surface measurements
In the present work, we developed a new formulation for the estimation of the soil moisture in the root zone based on the measured value of soil moisture at the surface. It was derived from a simplified soil water balance equation for semiarid environments that provides a closed form of the relation...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2014-03-01
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| Series: | Hydrology and Earth System Sciences |
| Online Access: | http://www.hydrol-earth-syst-sci.net/18/1199/2014/hess-18-1199-2014.pdf |
| Summary: | In the present work, we developed a new formulation for the estimation of the
soil moisture in the root zone based on the measured value of soil moisture
at the surface. It was derived from a simplified soil water balance equation
for semiarid environments that provides a closed form of the relationship
between the root zone and the surface soil moisture with a limited number of
physically consistent parameters. The method sheds lights on the mentioned
relationship with possible applications in the use of satellite remote
sensing retrievals of soil moisture. The proposed approach was used on soil
moisture measurements taken from the African Monsoon Multidisciplinary
Analysis (AMMA) and the Soil Climate Analysis Network (SCAN) databases. The
AMMA network was designed with the aim to monitor three so-called mesoscale
sites (super sites) located in Benin, Mali, and Niger using point
measurements at different locations. Thereafter the new formulation was
tested on three additional stations of SCAN in the state of New Mexico (US).
Both databases are ideal for the application of such method, because they
provide a good description of the soil moisture dynamics at the surface and
the root zone using probes installed at different depths. The model was first
applied with parameters assigned based on the physical characteristics of
several sites. These results highlighted the potential of the methodology,
providing a good description of the root-zone soil moisture. In the second
part of the paper, the model performances were compared with those of the
well-known exponential filter. Results show that this new approach provides
good performances after calibration with a set of parameters consistent with
the physical characteristics of the investigated areas. The limited number of
parameters and their physical interpretation makes the procedure appealing
for further applications to other regions. |
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| ISSN: | 1027-5606 1607-7938 |