Investigation of plant cover on water balance components in extreme rainfall events (Case study: Kakhk Paired Watershed of Gonabad)

Objective: Reducing the volume and intensity of surface runoff in watersheds is of great importance as one of the central issues in natural resource management, especially watershed management and soil conservation. plant cover, with significant effects on the hydrological cycle, is an important factor in increasing water infiltration and reducing flooding.Method: This study was conducted to investigate the effect of plant cover on water balance components in the Kakhk Gonabad paired basin of Khorasan Razavi province. Experiments were conducted on 10 experimental plots measuring 120 × 89 cm, at 2 low and high slopes (15-25 percent and 40-55 percent) and a rainfall intensity of 84 mm/h using a rain simulator. The plots included five types of plant cover (bunchgrasses, forb, shrub and Combination cover, without cover) with two replications. Runoff, sediment load, and soil loss data were collected from the reservoirs at the ends of the plots, and soil moisture was measured with a TDR device in two stages (before and after rainfall).Results: The results showed that plot number 2, with 73% shrub cover, had the lowest runoff (2.2 liters) and soil loss (40.3 grams). Also, the slope of the land had a significant effect on runoff and water infiltration.Conclusions: These findings emphasize the importance of selecting appropriate plant species, with characteristics such as strong roots and dense cover, in soil and water conservation programs.