soil detachment is known as an important process in soil erosion and its quantification is necessary to establish a basic understanding of erosion. this study was carried out to find the best flow erosivity indicator(s) for predicting detachment rate at low slopes. for this purpose, 12 experiments including 6 flow discharges (75, 100, 125, 150, 175 and 200 ml/s) and 2 slope gradients (1.5 and 2...

a new parametric model was developed for predicting cut point of hydraulic classifiers. the model directly uses operating parameters including pulp flowrate, feed particle size characteristics, pulp solids content, solid density and particles retention time in the classification chamber and also covers uncontrollable errors using calibration constants. the model applicability was first verified...

abstract using mathematical models for irrigation management have great impacts to increase irrigation efficiency and product amount, in fields. in this study, simulation results by swap model for moisture, compared with soil profiles moisture values, measured in the field. moisture data, measured at three wheat farms in the neyshabur plain, were used to predict moisture. results show good agre...

soil water content is one of the most important parameters for estimating irrigation frequency and providing the plant’s water requirement. since measurement of soil water content is both expensive and time consuming, water movement models are used to estimate these values. in this study, leachw model was used to estimate soil water content for two “dry” (20-29 aug) and “wet” (1-6 jul) periods ...

In order to improve the impact performance, the structure of hydraulic hammer should be optimized. In this paper, the ranges of eight vital structure parameters of piston and reversing valve system of hydraulic hammer were selected firstly; and then found the best value of different parameters under experiments with the method of computer optimization and the parametric analysis method provided...

Developing correlations between various soil parameters are considered the major challenge to diminish time and cost associated with field measurements. Soil hydraulic and physical properties were extensively characterized using tension disc infiltrometer and soil sampling in a silty clay agricultural field in Kalaat El-Andalous, Tunisia. Tension disc infiltrometer experiments were conducted at...

Stochastic modeling of soil water fluxes in the absence of measured hydraulic parameters requires a knowledge of the expected istribution of the hydraulic parameters in different soil types. Predictive relationships describing the hydraulic parameter distributions must be developed based on the common descriptors of the physical properties of soils (e.g., texture, structure, particle size distr...

in this study, hydrus2d/3d software was used to estimate the hydraulic parameters of van genuchten-mualem model via inverse modeling using double-ring infiltrometers data in 3 different soil textures. nine scenarios of inverse modeling (divided in three groups) were considered with different number (5, 4 and 3) of fitted hydraulic parameters for optimization. in the first group, simulation was ...

Upscaled soil hydraulic properties are needed for many large-scale hydrologic applications such as regional and global climate studies and investigations of land–atmosphere interactions. Many larger scale subsurface flow and contaminant transport studies also require upscaled hydraulic property estimates. The objectives of this study were to develop a methodology for upscaling hydraulic propert...