Objective: Hydrological drought is a part of the natural flow regime, but severe and prolonged events can lead to reduced river flows, limiting human uses and diminishing environmental flow availability. the aim of this study is to assess hydrological drought in the shoor river catchment area using the streamflow drought index (SDI).
Method: In this study, the status of hydrological drought in the shoor river catchment area was assessed using the streamflow drought index (SDI) on monthly and annual scales during the statistical period 1983–2023. for this purpose, annual precipitation data from the Masjedsoleyman synoptic station and annual discharge data from the dasht bozorg hydrometric station in the shoor river catchment area were used. the Mann–Kendall test was also used to determine the trend of discharge variations.
Results: The results of the streamflow trend analysis using the Mann–Kendall test indicated a decreasing trend in basin discharge at a 95% confidence level. the results of the streamflow drought index (SDI) indicate that during the early years of the statistical study period (1983–1999), the dasht bozorg hydrometric station generally experienced either no drought or intermittent mild droughts, and from the year 2000 to the end of the statistical period, the severity of droughts has increased. in general, the final years of the study period were associated with more severe drought conditions.
Conclusions: The results indicate that severe and extreme droughts did not occur at this station during the study period, and in most cases mild drought or no drought conditions prevailed.