2:15 PM - 2:30 PM
[MIS01-13] First results of modelling hydrological and thermal regime of West Siberia wetlands.
Keywords:West Siberia, wetlands, environmental modelling
Mathematical modeling of heat and mass transfer processes in wetlands
of different types was based on the scheme of the active land layer in the climatic model of the INM RAS (Volodin et al., 2010; Bogomolov et al., 2016). The scheme includes a multilayer (23 levels) soil model describing the transport of heat, liquid moisture, taking into account its freezing/melting, and water vapor, as well as a multilayer scheme of heat transfer in the snow cover.
One of the goals of this work is to reproduce the temperature regime of organic soils, for which the influence of organic matter content on soil characteristics was taken into account. The model proposes to calculate the thermophysical characteristics of soil (heat capacity, thermal conductivity, porosity, etc.) as a linear combination of these parameters for mineral and organic soils, taking into account the mass content of the amount of organic matter.
The soil thermal conductivity coefficient is determined by the interaction of the solid, liquid, and gaseous phases of the soil, so it depends substantially, first and foremost, on its moisture content [Shein, 2005]. Thus, at low values of moisture in the soil, the molecular mechanism of heat transfer prevails and the heat transfer coefficient changes weakly. With increasing moisture content, vapor diffusion heat transfer develops and an exponential growth of the thermal conductivity coefficient depending on soil moisture content is observed. However, in moisture-saturated soils, vapor diffusion transfer weakens and heat transfer is reduced to convection, which is extremely weakly expressed in soils, as a result of which the growth of the thermal conductivity coefficient practically stops.
In the used modification of the model, heat and moisture transfer is calculated in a porous medium with individual properties for each mole level. This made it possible to model soils having a complex structure of the soil profile, e.g. bog ecosystems (peat deposit and mineral soil layer under it).
Vegetation parameters in the model include coefficients of stomatal resistance dependence on air humidity, soil moisture potentials of plant wilting onset, maximum leaf index (LAI), maximum root system depth of plants. In the active layer model, the groundwater table is calculated taking into account horizontal runoff and precipitation.
Correct consideration of such components of the active layer of land as wetland ecosystems is important not only for determining the thermodynamic properties of soil, but also essential for the correct reproduction of the hydrological cycle of land within the framework of Earth system model.
of different types was based on the scheme of the active land layer in the climatic model of the INM RAS (Volodin et al., 2010; Bogomolov et al., 2016). The scheme includes a multilayer (23 levels) soil model describing the transport of heat, liquid moisture, taking into account its freezing/melting, and water vapor, as well as a multilayer scheme of heat transfer in the snow cover.
One of the goals of this work is to reproduce the temperature regime of organic soils, for which the influence of organic matter content on soil characteristics was taken into account. The model proposes to calculate the thermophysical characteristics of soil (heat capacity, thermal conductivity, porosity, etc.) as a linear combination of these parameters for mineral and organic soils, taking into account the mass content of the amount of organic matter.
The soil thermal conductivity coefficient is determined by the interaction of the solid, liquid, and gaseous phases of the soil, so it depends substantially, first and foremost, on its moisture content [Shein, 2005]. Thus, at low values of moisture in the soil, the molecular mechanism of heat transfer prevails and the heat transfer coefficient changes weakly. With increasing moisture content, vapor diffusion heat transfer develops and an exponential growth of the thermal conductivity coefficient depending on soil moisture content is observed. However, in moisture-saturated soils, vapor diffusion transfer weakens and heat transfer is reduced to convection, which is extremely weakly expressed in soils, as a result of which the growth of the thermal conductivity coefficient practically stops.
In the used modification of the model, heat and moisture transfer is calculated in a porous medium with individual properties for each mole level. This made it possible to model soils having a complex structure of the soil profile, e.g. bog ecosystems (peat deposit and mineral soil layer under it).
Vegetation parameters in the model include coefficients of stomatal resistance dependence on air humidity, soil moisture potentials of plant wilting onset, maximum leaf index (LAI), maximum root system depth of plants. In the active layer model, the groundwater table is calculated taking into account horizontal runoff and precipitation.
Correct consideration of such components of the active layer of land as wetland ecosystems is important not only for determining the thermodynamic properties of soil, but also essential for the correct reproduction of the hydrological cycle of land within the framework of Earth system model.