Taking coal mining subsidence farmland with high groundwater level as the research object

the distribution of soil thermal conductivity and the influencing factors under three different reclamation modes

including regional leveling reclamation

filling reclamation

and dynamic reclamation were studied. In this research

soil profiles of three layers

i.e. 0-20 cm

20-40 cm

and 40-60 cm

were dug in typical areas under three different reclamation modes. After collecting soil samples

soil thermal conductivity and other relevant physical indicators were acquired through experiments. The results indicated that reclamation mode

profile layer

and their interactions were the factors making the soil thermal conductivity different significantly (p < 0.01)

and the contribution rate was 86.8%

89.6%

and 71.9%

respectively. The changing trend of the soil conductivity showed a pattern of ">" with the increasing of soil depth. Reclamation could influence soil thermal conductivity significantly (p < 0.05)

and increase its differentiation of distribution among soil layers. Under the same conditions of soil water content and temperature

soil silt content was the main factor affecting soil thermal conductivity when soil bulk density was between 1.205 and 1.593 g/cm3

while soil sand content was the main factor when soil bulk density was between 1.604 and 1.813 g/cm3. Thermal conductivity of reclaimed soils was lower than that of the normal soil

and its differentiation of distribution among soil layers was higher. Therefore

in order to improve thermal conductivity of reclaimed soils

soil bulk density and texture shou be taken into consideration comprehensively

and soil bulk density should be reduced.