Two-dimensional computation model for simultaneous soil water and heat transport in bare soil with various topography

The amount of hat available on soil surface is one of the major factors, which affects the temperature and moisture content of soil profile. Previous researches reported that amount of accepted solar radiation differs with topographic features of field, which is ultimate source for heat available on soil surface. Moreover, temperature and moisture content of soil profile is affected by the inclination of field. Therefore, an investigation is carried out to verify the impact of topographic feature on simultaneous soil moisture and heat flow. Furthermore, the main factors which induce the heat and moisture flow in soils with inclined topography are also investigated. For this purpose research ws conducted on flat field and on north and south facing field, with 20 degrees C inclination. The results showed that, south facing field has higher soil temperature profile and a bit drier soil moisture profile than in other types of topography. North facing field has lower soil temperature and slightly wetter soil moisture profile. In this study direction along the soil surface direction is expressed as surface direction and direction normal to surface direction is denoted as depth direction. Soil moisture flow along the surface direction can not be expected even topography has some inclination until and unless soil profile is too much wet to occur gravity flow or rainfall intensity is higher than intake rate of soil. It is further investigated that heat flow in soils is solely governed by the product of temperature gradient of depth direction and thermal conductivity. Whereas, soil moisture flow is significantly effected by the product of gravitational head gradient of depth direction and moisture conductivity i.e. the gradient of flux potential. Furthermore,it is investigated that no any types of gradient of surface direction has any effect on soil moisture and heat flow