Analysis of Long-Term Changes in Hydro-Climatic Components (Case Study: Maroun Sub-Basin)

This research investigates the trends and changes in the statistical distribution of climatic parameters (the warm days index, TX۹۰p, and precipitation) and hydrological parameters (river flow discharge) in the Maroun basin over a ۵۰-year period (۱۹۷۱-۲۰۲۰). The Mann-Kendall test was employed to identify trends, and the Pettitt test was used to determine the timing of abrupt changes. The results indicated that the TX۹۰p index exhibits a statistically significant increasing trend (p-value = ۰.۰۱۸), with a change point in the year ۱۹۹۵, following which its mean value increased by ۵۷%. Although the decreasing trends in precipitation and discharge were not statistically significant at the ۹۵% level, the Pettitt test identified an abrupt change in both parameters in the year ۲۰۰۸. A comparison of the statistical distribution of the data before and after the change points, using Kolmogorov-Smirnov, analysis of variance, and location tests, confirmed that not only the central tendency but also the shape and dispersion of these parameters have changed significantly. Specifically, the mean precipitation and discharge decreased by ۲۸% and ۴۶%, respectively, while their standard deviations also decreased by ۳۸% and ۵۲%, respectively. These findings collectively indicate a shift in the regional climate pattern towards warmer and drier conditions, which has serious implications for water resources management.

کلیدواژه ها:

Extreme Temperature ، precipitation ، Thermal Index ، Trend Change