SCHRIFTENREIHE Institut für Pflanzenernährung und Bodenkunde ...

Under frozen conditions, the differences between simulated and measured water
contents could be also related to soil structural changes. Further work should
establish a relation between the impedance factor and soil hydraulic properties
that can be measured in the field. It is possible that measurements of soil
moisture characteristic curves under both frozen and unfrozen conditions are
helpful to provide a basis for this aspect.
A detailed knowledge of the soil-atmosphere interface is needed to improve the
surface runoff algorithm in the “freezing module”.
Our contributions to MAGIM project
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We mostly explored the spatial distribution of various regionalized variables,
which not only helped to quantify the environmental changes due to the grazing
effects at various scales, but also provided a basis for the regionalization,
interpolation, transferability and model upscaling from local scale to a large area
where the MAGIM project took place. Especially, we deliver a better process
understanding for grazing-induced changes in physical and hydraulic soil
properties and their effects on local and regional water and heat fluxes in
semi-arid regions. This should improve the assessment and prediction of
ecosystem changes caused by grazing management.
For further studies and possibly future prediction, the hydrological model
HYDRUS including freezing and thawing processes was parameterized and
validated. This is an important part for the integrated model network of MAGIM.
The calibrated hydraulic and thermal parameters is useful to other models, e.g.
SWAT model that will be used to calculate C, N and water fluxes in the Xilin
River catchment. The modeling products are also essential for inter-verification
between the related models. In addition, the modeling products are essential as
the additional information, which provide some data for the time and place which
sampling is not available. Certainly, the model will definitely serve to characterize
the present conditions, and further to predict the future conditions.