The role of vegetation management on surface runoff (Case study: Kechik catchment in north-east of Golestan Province)

The vegetation and plant cover decrease the velocity of surface runoff and increase the soil infiltration rate. Consequently plant cover has an important role to reduce destructive floods. The study area with its erodible soil, is faced to natural hazards as well as soil erosion. This paper was prepared according to a research project findings aimed to investigate the relationship between plant cover and surface runoff. The study area is a part of kechik watershed that is distinguished as a set of pair catchment protected for about 5 years. Two catchments including protected and unprotected have been considered as hydrologic units. The basic information including physiography, geology and hydrology were collected. The plant cover was measured through 1*1 random-systematic quadrats. The rainfall and its related discharge were measured. Statistical tests were also performed to determine the difference and relationship between two catchments via Spss and Minitab softwares. The results showed that the  differences in plant cover of the catchments were significant at p=0.05 level the average of plant coverages were %96.2, % 52.9 and the runoff amounts were %17.43, %35.38 in protected and unprotected catchments respectively. The regression coefficient between rainfall intensity and runoff were 0.76 and 0.8 for unprotected and protected catchments respectively. The difference between produced runoff of two catchments was significant at %1 level. In general it is believed that the protection at a management plan is one of the most important way of contro surface runoff and related flood that should be considered in watershed management specially in the study area in North-eastern of Golestan province.