## 4 Results and Discussion
### Radionuclide Activity Concentrations  
The measurement data of the \({}^{238}\)U, \({}^{232}\)Th, and \({}^{40}\)K activity concentrations of 380 Wadi sediments are presented in Table S1 (Supplementary Materials). The spectrometric measurements were performed directly in the field. Table 3 displays the descriptive statistical analysis (mean, standard deviation, minimum, maximum, skewness, kurtosis, and coefficient of variance) for the radionuclide activity concentrations besides the radiological hazard parameters. The mean values Mean \(\pm\) SD (Min/Max) of the \({}^{238}\)U, \({}^{232}\)Th, and \({}^{40}\)K activity concentrations are registered as 62.2 \(\pm\) 20.8 (13.6/130.9), 84.2 \(\pm\) 23.3 (30.0/192.0), and 949.4 \(\pm\) 172.5 (375.6/1471.1) Bq kg\({}^{-1}\), respectively. The mentioned mean values of the \({}^{238}\)U, \({}^{232}\)Th, and \({}^{40}\)K activity concentrations are approximately two times higher than the recommended values 33, 45, and 412 Bq kg\({}^{-1}\), respectively [1]. As can be noticed in Table 3, the activity concentration of \({}^{232}\)Th in the studied Wadi sediments is greater than \({}^{238}\)U, and thorium is less susceptible to leaching than uranium, thus the increase in thorium levels is usually larger due to the resistance of thorium minerals to weathering [32]. In addition, the radionuclide concentration elevations in the Wadi sediments can be depicted due to the weathering, leaching, alteration, and aeration processes. This leads to the accumulation of a high content of radioactive minerals, such as uranothorite as well as radioactive bearing minerals, such as monazite, zircon, allanite, and yettrocolombite, and the different alteration zones (episyenitization, kaolinization, albitization, and hematitization) from the surrounding granitoids, such as synogranite, alkali feldspar granite, and quartz syenite. Due to the presence of a wide range of minerals in potassium, such as feldspar, micas, and clay, the measured results depict that the \({}^{40}\)K activity in the analyzed samples is greater than that of \({}^{238}\)U and \({}^{232}\)Th. The skewness values describe the asymmetric distribution based on the fundamental statistical analysis of radionuclide activity concentrations, with positive values referring to the asymmetrical distribution. Whereas their negative values suggest that the tail of the asymmetrical distribution is extended to negative values, the tail of the asymmetrical distribution is extended to negative values. Therefore, the positive skewness values of the \({}^{238}\)U and \({}^{232}\)Th activity concentrations imply a positive asymmetrical nature, whereas the negative skewness values of the \({}^{40}\)K activity concentrations indicate a negative asymmetrical nature. Secondly, the kurtosis values reflect the Preakness probability distribution. The probability distribution is peaked in the analyzed study because the kurtosis values for the \({}^{238}\)U, \({}^{232}\)Th, and \({}^{40}\)K activity concentrations are positive. As clarified in Table 3, the standard deviation data of all investigated samples are observed to be small and lower than the mean of the \({}^{238}\)U, \({}^{232}\)Th, and \({}^{40}\)K activity concentrations, which reveals a high degree of uniformity of the detected radionuclides in the Wadi sediments. The coefficient of variance (CV) is presented in Table 3 with moderate values of 33% and 28% for the \({}^{238}\)U and \({}^{232}\)Th activity concentrations, respectively, while the low value was 18% \({}^{40}\)K in the analyzed data. The variation may be due to the existence of the host minerals of uranium and thorium in the examined samples. \begin{table}
\begin{tabular}{c c c c c c c c c c c} \hline \hline  & **N** & **Mean** & **SD** & **Min** & **Max** & \ \begin{tabular}{c} **Lower** \\ **95\% CI** \\ **of Mean** \\ \end{tabular}  & \begin{tabular}{c} **Upper** \\ **95\% CI** \\ **of Mean** \\ \end{tabular}