THE ANALYSIS OF SOIL TEMPERATURES IN DIFFERENT DEPTHS USING SPEARMAN’S RHO AND MANN-KENDALL CORRELATION TESTS: THE CASE STUDY OF NIGDE CENTER IN TURKEY

Abstract

This research was conducted to determine soil temperatures in different soil depths in located Turkey’s Anatolia Region in Center of Nigde Province. In the study, the maximum, minimum and average soil temperature values of 10 cm, 50 cm and 100 cm depths observed between 1970-2019 were examined. All soil temperature data were evaluated monthly within the scope of the study. In the study, Mann-Kendall, Sperman's Rho correlation test and Sen's slope method were used.  According to the research result; The average of maximum soil temperatures in 10 cm depth was calculated as 6,8 0C in winter months and 20,7 0C in spring months. The average minimum soil temperature was calculated as 0,3 0C in winter and 5,0 0C in spring Months in long periods Generally, it was observed that there was an increasingly significant trend at maximum temperatures of 10 cm depth. According to the Mann-Kendal facility, a significant increase trend was observed in minimum soil temperatures in spring, winter and Summer months except for the months of autumn. Considering the average maximum temperature values in 50 cm; It was calculated as 6,6 °C in winter and 13,6 °C in spring months. The minimum soil temperature average was calculated as 3,5 0C in winter and 8,3 0C in spring months in long period (50 year, 600 months). In general, it was observed that there was an increasingly significant trend at maximum temperatures of 50 cm soil depth. According to Mann-Kendall and Sperman Rho test, a significant increase trend was observed in minimum soil temperatures in all seasons except for autumn months. According to the average maximum temperature values in 100 cm depth; It was calculated as 9,2 0C in winter and 11,5 0C in spring. The minimum soil temperature average was calculated as 7,1 0C in winter and 8.7 0C in spring months. It has been observed that there is a significant increase trend in the increasing of maximum and minimum soil temperatures of 100 cm soil depth.