Influenced by global climate change, rainfall characteristics have changed in recent years, especially in arid regions. However, the actual response of the watersheds' hydrological indicators to erosive rainfalls has not been understood yet. Therefore, this study sought to investigate the changes in the watersheds' hydrological response due to the intra-rainfall indices of various events in the Dehgin paired watershed in Hormozgan, Iran, using the data collected from 2007 to 2019. To this end, first, all rainfall events which elicited the response of watersheds were identified concurrently based on the meteorological and flume data. Then, the qualitative and quantitative intra-storm variations associated with hydrological indicators (i.e., total runoff and discharge variables) were extracted for statistical analysis. The study's results revealed that (1) the increasing rates of the continuous discharge time of the control and treatment watershed's front position were about 2.25 and 4.76 times the rear position, respectively. (2) A strong linear relationship was found between total runoff volume and variables including precipitation of storm and time to storm peak in both control and treatment watersheds, with the R2 reported to be 67.7 and 63.6%, respectively. (3) It was also found that the watershed management operations reduced the variables' values including the maximum discharge, the discharge variation coefficient, continuity time of discharge, the peak of the time to discharge, the number of discharge peaks, and the total runoff volume by 3, 1.6, 2.25, 2.37, 2.42, and 3.27 times, respectively. Therefore, it could conceivably be argued that extreme rainfalls can be controlled by management practices in the watersheds.
Keywords: Intra-rainfall characteristics; Regression models; Watershed management operation.
© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.