Assessing the Relationship between Ground and Soil Temperature at Different Depths: A Case Study of Kermanshah Province

The study of soil temperatures at different depths is significant from various perspectives, including meteorology, climatology, agriculture, industry, and other related bio - activities. Vertical distribution of temperature in soil depends upon three factors, namely: 1) the structure and physical characteristics of soil and its thermal properties; 2) land cover (bare, grass, snow, etc.); 3) the effect of climatologic factors including temperature, precipitation, wind, solar radiation, and humidity. This paper reports the results of a statistical study on the relationship between ground and soil temperature at different depths (10, 50, and 100 cm) in five synoptic stations in Kermanshah province. Methodology Exact measurement of ground heat flux is a formidable task. Most techniques measure the ground heat flux by measuring the soil temperature at different depths. Given the difficulty of such measurements, it seems that developing the statistical modeling's could be useful. Data were collected for daily minimum air temperatures (meteorological screen) and daily minimum ground temperatures, in addition to soil temperatures at 10, 50, and 100 cm depths at 6:30 am and 6:30 pm local time within a 14-years period (1993 to 2006), adopted from the Kermanshah Regional Meteorological Office. The data were then used to study the relationship between the ground and soil temperature at different depths. The paired-samples t-test was employed to analyze the data. In addition, a multivariate regression model was employed to estimate temperatures at various soil depths (10, 50, 100 cm) based upon variables including ground temperature, Julian day, and depth