Gas content of soils - the total amount of gases contained in a unit mass or volume of soil in a given environment. One of the main quantitative indicators of the gas content in soils.
Indicators
There are two indicators: volumetric and mass gas content.
Volumetric gas content (G v ) characterizes the total content of free and adsorbed gases per unit volume of soil (V) and is numerically equal to the volume of gas contained in 1 cm 3 of soil under given conditions (pressure): G v = V g / V, where V g - the volume of gas contained in the soil; V is the volume of soil. The value of G v is measured in cm 3 / cm 3 or m 3 / m 3 .
Mass gas content (G m ) characterizes the total content of free and adsorbed gases per unit mass of soil (m) and is numerically equal to the volume of gas contained in 1 g of soil under given conditions (pressure): G m = V g / m, where V g - the amount of gas contained in the soil; m is the mass of soil. The value of G m is measured in cm 3 / g or m 3 / t.
The gas content of the soil (G) characterizes the relative volume of gas contained in the pores of the soil . It is numerically equal to the ratio of the volume of gas in the soil pores to the volume of the whole soil: G = (V g /V).100, where V g is the volume of gas in the soil pores; V is the volume of soil. The value of G is measured in%, it depends on humidity and varies from 0 (in the absence of gases and complete water saturation) to a value corresponding to the porosity of this soil (when the pores are completely filled with air).
The maximum gas content of a given soil, corresponding to its porosity and determined when all pores are completely filled with gas (no moisture), is called the soil air capacity (B) and is measured, like porosity, in%. Numerically, the air volume is equal to the porosity of the soil.
Gas Factors
Gas content depends on many factors, porosity and sorption capacity of the soil , its moisture content , as well as on the type of gas, on thermodynamic conditions: external pressure, temperature, etc.
Literature
- Basic concepts of engineering geology and environmental geology: 280 basic terms./ Ed. V.T. Trofimova. - M., JSC Geomarketing, 2012, 320 p.
- Soil Science / Textbook. Ed. V.T. Trofimova, 6th ed. M.: Publishing House of Moscow State University, 2005, 1024 pp.
- Korolev V.A. Gas content of soils / Russian Geological Encyclopedia. In three volumes. Volume 1 (AI). - M. - St. Petersburg: VSEGEI Publishing House, 2010.P. 263