Low flow is very sensitive to climate change and human intervention, especially in arid regions. In this study, changes of the 7-day low flow along the most important rivers of Iran's Namak Lake Basin were investigated using nonparametric (Mann-Kendall and modified-Mann-Kendall) tests. A significant diminishing trend was observed in 72.2% of stations during the period of 1970-2012. The northern part of the basin lacked a significant trend, while in other parts of the basin, the descending trend was distributed uniformly. On the other hand, the changes of the annual rainfall during this period showed no clear trend (a significant trend in 36% and non-significant trend in 64% of stations), and the identified pattern of its changes was complicated on the basin scale and during the year. On a monthly scale, a significant decreasing trend was observed in March as one of the most productive months of the year in 49% of the stations. In addition, rainfall reduction was significant (over 35%) over the past 15 years in more than 71% of the stations. Also, changes in the proportion of seasonal rainfall and rainfall regime were considerable. The share of winter and spring rainfall showed a diminishing trend in 90% and 82% of stations, respectively. Also, rainfall regime based on precipitation concentration index (PCI) revealed a tendency to disorder (in 53% of stations). The annual temperature and temperature of October and February indicated a strong ascending trend in 92%, 71%, and 64% of stations, respectively, which can be effective during snow melting in basins with snow-rainy regimes and increasing evapotranspiration. Groundwater level changes also showed that, in the studied plains, the average water table drawdown was between 0.31 and 1.33 m/year. Therefore, the observed trend of low flow rates in this basin reflects the impact of climate change, where both direct and indirect human interference has led to the exacerbation of this situation.