Evaluating the effect of geocell with vegetation and gravel on changes in the effective parameters of runoff using a rainfall simulator (case study: Iran)

Abstract

Permeable pavements can reduce the negative effects of flooding in urban areas. This research seeks to study and compare the performance of the impervious surface as a control (O), sandy loam (SL), gravel (G), gravel with geocell layer (GGE), rosemary (R), rosemary with geocell layer (RRE), turf (T), and turf with geocell layer (TGE) in reducing runoff volume (RV), time to start runoff (TR), runoff coefficient (C), time to end runoff (TER), peak flowrate (PF), time to peak (TP), and time base (TB) under six different rainfall intensities (i) and two different slopes (s) using a rainfall simulator. For this purpose, 96 physical models were considered at the laboratory level. For the dependent variables TR, TER, PF, TP, and TB, there was a significant difference between the data at the level of 5% in all cases. Based on the results, changes in rainfall intensity, slope, and type of treatment could make a significant difference in the results of the C parameter. All treatments were able to reduce runoff volume in all test conditions. Rosemary had a better performance in controlling runoff and parameters affecting it compared to turf. The maximum and minimum cumulative runoff volumes observed for treatment GGE are 85.4 and 2 L, respectively. Finally, the results revealed that GGE could perform better in reducing runoff and cumulative volume in all cases compared to the rest of the test groups. The highest percentage of runoff volume reduction in GGE treatment was 96.5%.