تعمیم نتایج کرت‎های آزمایشگاهی و صحرایی فرسایش تحت باران شبیه‎سازی شده

Different methods of measuring runoff and erosion may lead to different results, which are not necessarily related to specific effects of studied variable on erosion. Although runoff, erosion and sediment studies on the prepared soil in the experimental plots is inevitable because of many advantages, but the disturbance and transport of soil and prepared experimental plots reduces the reliability of these studies. All methods of preparing soils for use in laboratory experiments have one basic objective, namely, that the prepared soil sample should be as homogeneous as possible. Changes in soil during collecting, transport and preparation procedures including air drying, sieving and especially the effects of soil moisture during this process and finally, increasing the bulk density of the soil surface may affect the results of the runoff and erosion. A case study was therefore conducted to compare the surface runoff, sediment concentration and soil loss from the field plots with disturbed soil (prepared for experimental erosion plots) and undisturbed (natural soil). The results showed that the effect of soil disturbance on all variables including time to runoff, runoff volume and coefficient, sediment concentration and soil loss was significant (p≤0.01). Time to runoff, runoff volume and coefficient, sediment concentration and soil loss increased by 2.29, 3.45, 2.79, 2.83 and 11.50 times respectively after soil disturbance.