Time series of discharge changes in Karkheh watershed using parametric and nonparametric methods

The study of river flow trends in water management and irrigation and water management is an important issue. In addition, monthly, seasonal and annual discharge trends of Karkheh watershed were evaluated using non-parametric Mann-Kendall tests, Sen's slope estimator and regression analysis. Inverse distance weighting method was also used to study the spatial variation of discharge trends in Karkheh watershed. Accordingly, discharge data from the eleven wells of the above-mentioned basin for the period 1990 to 2018 were used. The results of this study showed that Dubai has had annual rainfall at all of these stations, except for Mir-Sayed Ali. The values of this major are Hamidieh, Pai Pol, Pol Zal, Poldokhtar, Afrin, Cham Fig, Noorabad, Doab Merak, Kakarza and Pulchehr, respectively, 48, 33, 16, 5, 15, 4, 0.4, 1.4, respectively. It decreased by 2.6 and 13 cubic meters, while it increased by 0.4 cubic meters at the Sarab Ali station. Based on the findings of the study, applying nonparametric Mann-Kendall method and age in trend analysis of monthly, seasonal and annual discharge series have shown that the performance of these two tests are similar at times and when the frequency of duplicate data is high, the age method can be answered. More realistic than Mann-Kendall's approach, this approach can be applied to future water, water planning and management.