نوع مقاله : پژوهشی
نویسندگان
1 دانشجوی دکتری، گروه مهندسی آبخیزداری، دانشکده منابع طبیعی، دانشگاه تربیت مدرس، نور، ایران
2 گروه مهندسی مناطق خشک و کوهستانی، دانشکدگان کشاورزی و منابع طبیعی دانشگاه تهران
3 گروه آبخیزداری، دانشکده منابع طبیعی، دانشگاه تربیت مدرس، نور، مازندران، ایران
چکیده
کلیدواژه‌ها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Introduction and Objective: Soil erosion is one of the most important environmental, natural resource and agricultural problems in the world. Soil splash is the first stage after the impact of raindrops on the soil surface, which causes the degradation of soil aggragated and the detachment of soil particles, which results in splash erosion, which reduces soil permeability, increases runoff, and sheet erosion, consequently.Therefore, the accurate estimation of splash and sheet erosion is necessary for the success of soil conservation erosion control and reduction of natural hazards. In this regard, new methods have been devised using photography and image processing techniques to estimate splash and sheet erosion. The aim of this research was to validate the splash and sheet erosion estiamtesusing synthetic colour-contrast aggregates.
Materials and Methods: Synthetic colour-contrast aggregates were first prepared using mineral pumice particles and yellow concrete colour. Then, the soil with silty-clay-loamy texture was sampled from the Marzanabad-Kandalus road bank, and natural and synthetic colour-contrast aggregates with diameters of 1.77, 2.89 and 4.05 mm were separated. sheet erosion was then measured in 20×40 cm plots and splash measurements were performed using the splash cup method at a rainfall intensity of 60 mm hr-1 and duration of 10 min and in three repetitions.
Results and Discussion: The results showed that the average rates of net splash for different soil aggregate diameters of 1.77, 2.89 and 4.05 mm, were 73.72, 38.73 and 20.68 g m-2, respectively, and also the average rates of total splash were 192.61, 73.97, and 44.46 g m-2, respectively, which indicates a decrease in the average amount of total and net splash with increasing in the soil aggregate diameter. The results showed that synthetic colour-contrast aggregates have an acceptable efficiency for measuring net splash, total splash and sheet erosion with coefficients of determination of 82, 70 and 82%, respectively. The results also showed that the average soil loss for different soil aggregate diameters of 1.77, 2.89, and 4.05 mm, were 94.69, 83.22, and 42.20 g m-2, respectively, and in other words, sheet erosion decreased with increasing the diameter of soil aggregate on the soil surface.
Conclusion and Suggestions: According to the results of this research, it is possible to estimate splash erosion and sheet erosion on a plot scale with acceptable accuracy by using synthetic colour-contrast aggregates, with less cost and in a shorter time.
کلیدواژه‌ها [English]
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