# Homogeneity and Trend Analysis of Climatic Variables in Cap-Bon Region of Tunisia
## 3 Results and Discussion
### Trend in Climatic Variables  
3.2.1. Trend in Annual, Seasonal and Monthly Air Temperature  
Sen's slopes of the annual, seasonal and monthly tendencies in Tmax time series obtained from the MK, mMK and TFPWMK tests are shown in Table 2. Sen's slopes of significant trends (95% levels) are presented in bold characters in the table. Despite dividing the time series of annual Tmax at the significant change point (2000), a significant increasing trend was recorded for both divided parts. Thus, the warming trend in the annual Tmax must be accepted as evidence, which is probably due to the increase in \begin{table}
\begin{tabular}{l c c c c c c c c c} \hline \hline  & \multicolumn{4}{c}{**Before Break Point If Any**} & \multicolumn{4}{c}{**After Break Point If Any**} \\ \cline{2-10}  & **MK** & **mMK** & **sen** & **TFPWMK** & **Sen** & **MK** & **mMK** & **sen** & **TFPWMK** & **Sen** \\  & **\(p\)-Value** & **\(p\)-Value** & **\(p\)-Value** & **\(p\)-Value** & **\(p\)-Value** & **\(p\)-Value** & **\(p\)-Value** & **\(p\)-Value** & **\(p\)-Value** & **\(p\)-Value** \\ \hline Annual & **0.050** & **0.050** & **0.036** & **0.041** & **0.043** & **0.025** & **0.011** & **0.040** & **0.108** & **0.041** \\ Winter & 0.105 & 0.105 & 0.021 & 0.066 & 0.021 & 0.021 & 0.026 & 0.021 & 0.026 & 0.026 \\ Spring & 0.058 & 0.058 & 0.060 & 0.108 & 0.064 & 0.057 & 0.057 & 0.042 & 0.112 & 0.040 \\ Summer & 0.112 & 0.112 & 0.030 & **0.025** & **0.041** & 0.327 & 0.327 & 0.049 & 0.762 & 0.022 \\ Autumn & 0.266 & 0.266 & \(-\)0.022 & 0.300 & \(-\)0.022 & 0.338 & 0.338 & 0.019 & 0.319 & 0.024 \\ January & 0.095 & 0.095 & 0.033 & 0.056 & 0.026 & & & & & \\ February & 0.364 & 0.438 & 0.022 & 0.365 & 0.022 & & & & & \\ March & 0.240 & 0.240 & 0.058 & 0.343 & 0.054 & 0.976 & 0.976 & \(-\)0.005 & 0.770 & \(-\)0.010 \\ April & 0.649 & 0.649 & 0.018 & 0.711 & 0.022 & 0.174 & 0.174 & 0.071 & 0.144 & 0.092 \\ May & 0.058 & 0.058 & 0.063 & 0.079 & 0.069 & 0.071 & 0.071 & 0.096 & 0.124 & 0.097 \\ June & **0.020** & **0.020** & **0.065** & **0.003** & **0.084** & 0.940 & 0.940 & \(-\)0.002 & 0.711 & 0.026 \\ July & 0.739 & 0.583 & 0.008 & 0.347 & 0.046 & 0.544 & 0.544 & 0.036 & 0.711 & 0.035 \\ August & **0.020** & **0.020** & **0.045** & **0.041** & **0.049** & 0.940 & 0.940 & \(-\)0.010 & 0.650 & 0.050 \\ September & 0.224 & 0.224 & 0.022 & 0.007 & 0.031 & 1.000 & 1.000 & \(-\)0.003 & 0.583 & \(-\)0.041 \\ October & 0.944 & 0.944 & \(-\)0.004 & 1.000 & 0.000 & 0.496 & 0.496 & \(-\)0.057 & 0.675 & \(-\)0.025 \\ November & 0.484 & 0.484 & 0.019 & 0.940 & 0.006 & 0.871 & 0.871 & 0.004 & 0.834 & 0.011 \\ December & 0.231 & 0.087 & 0.023 & 0.407 & 0.018 & & & & & \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Results of the statistical tests for Tmax. Figure 3: Change point in historical series of precipitation in December using Pettit test (mu1 and mu2 are the average of observed data before and after the changing point, respectively). urbanization and industrialization in the study region. The magnitude of the significant increasing trends estimated using Sen's slope method were 0.036 and 0.04 \({}^{\circ}\)C/year before and after the breakpoint, respectively. Our results are in the same order of magnitude as those reported by [PERSON] et al. (2018). The authors reported an increasing trend in Tmax, in different locations in Southern Spain, with Sen's slope values varying from 0.16 to 0.41 \({}^{\circ}\)C/decade. In the spring, summer and autumn seasons, where significant upward trends were observed in the whole data series, no significant trend was detected if the divided parts were analyzed separately. Furthermore, similar behavior was observed with the monthly time series (except for June and August). It is therefore evident that for seasons and months where a significant upward trend was observed for the entire dataset, it might have resulted from the abrupt point in the mean. In the first period (before the break point), the MK test detected a significant increasing trend in Tmax for June and August.