Sediment concentration modeling in rill flow using the Adaptive Nero Fuzzy Inference System (ANFIS) in semi arid region

IIn many semiarid regions of Iran, soil erosion has become a serious environmental problem affecting land productivity, nutrient loss, water quality, and freshwater ecosystems. Rates of soil loss differ according to erosion type and land degradation processes. Rill erosion is commonly observed when rainstorms occur on steep slopes and sediment transport in rill flows exhibits the characteristics of non-equilibrium transport. In this paper, sediment concentration of rill flow is estimated by adaptive neuro-fuzzy inference system (ANFIS). A series of mathematical equation and parameters effecting on` rill hydrodynamics and soil detachment were used for well-defined rill sediment concentration. A series of filed experiments were performed to evaluate the model. The stepwise method was used to selecting the most important and effective input variables from measured input parameters of soil properties, topographic and vegetation attributes affecting sediment concentration of rill flow. Based on the stepwise procedure the most significant parameters in the model predications were steep slope, vegetation percentage, clay percentage and shear stress parameters. The values of sediment concentration simulated by the model were in agreement with observed values with Coefficient of Correlation (R2), Root Mean Square Error (RMSE) and Mean Bias Error (MBE) of 0.697, 30.5 and 1.0, respectively. The results of the investigation show that the data-driven ANFIS modeling approach can be a powerful alternative technique for correctly estimating rill sediment concentration.