Analysis of soil hydraulic and thermal properties for land surface modeling over the Tibetan Plateau
Soil information (e.g., soil texture and porosity) from existing soil datasets over the Tibetan Plateau (TP) is claimed to be inadequate and even inaccurate for determining soil hydraulic properties (SHP) and soil thermal properties (STP), hampering the understanding of the land surface process...
| Main Authors: | , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2018-06-01
|
| Series: | Earth System Science Data |
| Online Access: | https://www.earth-syst-sci-data.net/10/1031/2018/essd-10-1031-2018.pdf |
| Summary: | Soil information (e.g., soil texture and porosity) from existing soil
datasets over the Tibetan Plateau (TP) is claimed to be inadequate and even
inaccurate for determining soil hydraulic properties (SHP) and soil thermal
properties (STP), hampering the understanding of the land surface process
over TP. As the soil varies across three dominant climate zones (i.e., arid,
semi-arid and subhumid) over the TP, the associated SHP and STP are expected
to vary correspondingly. To obtain an explicit insight into the soil
hydrothermal properties over the TP, in situ and laboratory measurements of
over 30 soil property profiles were obtained across the climate zones.
Results show that porosity and SHP and STP differ across the climate zones
and strongly depend on soil texture. In particular, it is proposed that
gravel impact on porosity and SHP and STP are both considered in the arid
zone and in deep layers of the semi-arid zone. Parameterization schemes for
porosity, SHP and STP are investigated and compared with measurements taken.
To determine the SHP, including soil water retention curves (SWRCs) and
hydraulic conductivities, the pedotransfer functions (PTFs) developed by
Cosby et al. (1984) (for the Clapp–Hornberger model) and the
continuous PTFs given by Wösten et al. (1999) (for the
Van Genuchten–Mualem model) are recommended. The STP parameterization scheme
proposed by Farouki (1981) based on the model of De Vries (1963) performed
better across the TP than other schemes. Using the parameterization schemes
mentioned above, the uncertainties of five existing regional and global soil
datasets and their derived SHP and STP over the TP are quantified through
comparison with in situ and laboratory measurements. The measured soil
physical properties dataset is available at
<a href="https://data.4tu.nl/repository/uuid:c712717c-6ac0-47ff-9d58-97f88082ddc0" target="_blank">https://data.4tu.nl/repository/uuid:c712717c-6ac0-47ff-9d58-97f88082ddc0</a>. |
|---|---|
| ISSN: | 1866-3508 1866-3516 |