The best design of subsurface trickle irrigation systems requires knowledge of water and salt distribution patterns around the emitters that match the root extraction and minimize water losses. The transient distribution of water and salt in a two-dimensional homogeneous Iraqi soil domain under subsurface trickle irrigation with different settings of an emitter is investigated numerically using 2D-HYDRUS software. Three types of Iraqi soil were selected. The effect of altering different values of water application rate and initial soil water content was investigated in the developed model. The coefficient of correlation (R2) and the root-mean-square error (RMSE) was used to validate the predicted numerical result. This statistical analysis revealed that there was no much difference between the predicted numerical results, and the measured values. R2 varied from 0.75 to 0.93 and the (RMSE) from 0.079 to 0.116. The comparison confirms the accuracy of the developed model, and it shows that it can be used to simulate the front wetting patterns of water and salt distribution under subsurface trickle irrigation systems. The simulation outcome showed that as the distance from the emitter increased, soil salinity far from the emitter decreased. As expected, irrigation duration and amount affects the dimension of the solute distribution.
In this research, the geotechnical properties of the soil profile in Hilla city within Babylon Governorate in the middle parts of Iraq are described. The geotechnical data at the specific sites were collected from some geotechnical investigation reports performed at some selected locations. This article is devoted to studying the distribution of soil properties (the physical and mechanical) in the horizontal and vertical directions. Moreover, a correlation between different physical and mechanical properties is performed. The correlation is executed using statistical analysis by Microsoft Excel Software (2016). From the regression results, it was found that the nature of the soil is c
Gypseous soil is prevalent in arid and semi-arid areas, is from collapsible soil, which contains the mineral gypsum, and has variable properties, including moisture-induced volume changes and solubility. Construction on these soils necessitates meticulous assessment and unique designs due to the possibility of foundation damage from soil collapse. The stability and durability of structures situated on gypseous soils necessitate close collaboration with specialists and careful, methodical preparation. It had not been done to find the pattern of failure in the micromechanical behavior of gypseous sandy soil through particle image velocity (PIV) analysis. This adopted recently in geotech
In this research, the geotechnical properties of the soil profile in Hilla city within Babylon Governorate in the middle parts of Iraq are described. The geotechnical data at the specific sites were collected from some geotechnical investigation reports performed at some selected locations. This article is devoted to studying the distribution of soil properties (the physical and mechanical) in the horizontal and vertical directions. Moreover, a correlation between different physical and mechanical properties is performed. The correlation is executed using statistical analysis by Microsoft Excel Software (2016). From the regression results, it was found that the nature of the soil is c
A field experiment was carried out during the 2020 season at the College of Agricultural Engineering/ University of Baghdad, Al-Jadriya to evaluate the effect of dry farming when applying water stress under the subsurface drip irrigation system on water productivity and rice yield. The experiment was conducted with three levels of irrigation water stress when 10, 20 and 40% of the available water was depleted and in three dimensions between drip lines 10, 15 and 20 cm. The experiment was designed according to a randomized complete block design, according to the split plot design, with three replications. Determine the depth of irrigation water depending on the moisture depletion of th
The 3-parameter Weibull distribution is used as a model for failure since this distribution is proper when the failure rate somewhat high in starting operation and these rates will be decreased with increasing time .
In practical side a comparison was made between (Shrinkage and Maximum likelihood) Estimators for parameter and reliability function using simulation , we conclude that the Shrinkage estimators for parameters are better than maximum likelihood estimators but the maximum likelihood estimator for reliability function is the better using statistical measures (MAPE)and (MSE) and for different sample sizes.
Note:- ns : small sample ; nm=median sample
... Show MoreMost available methods for unit hydrographs (SUH) derivation involve manual, subjective fitting of
a hydrograph through a few data points. The use of probability distributions for the derivation of synthetic
hydrographs had received much attention because of its similarity with unit hydrograph properties. In this
paper, the use of two flexible probability distributions is presented. For each distribution the unknown
parameters were derived in terms of the time to peak(tp), and the peak discharge(Qp). A simple Matlab
program is prepared for calculating these parameters and their validity was checked using comparison
with field data. Application to field data shows that the gamma and lognormal distributions had fit well.<
In this paper, the Azzallini’s method used to find a weighted distribution derived from the standard Pareto distribution of type I (SPDTI) by inserting the shape parameter (θ) resulting from the above method to cover the period (0, 1] which was neglected by the standard distribution. Thus, the proposed distribution is a modification to the Pareto distribution of the first type, where the probability of the random variable lies within the period The properties of the modified weighted Pareto distribution of the type I (MWPDTI) as the probability density function ,cumulative distribution function, Reliability function , Moment and the hazard function are found. The behaviour of probability density function for MWPDTI distrib
... Show MoreThis paper demonstrates the construction of a modern generalized Exponential Rayleigh distribution by merging two distributions with a single parameter. The "New generalized Exponential-Rayleigh distribution" specifies joining the Reliability function of exponential pdf with the Reliability function of Rayleigh pdf, and then adding a shape parameter for this distribution. Finally, the mathematical and statistical characteristics of such a distribution are accomplished
Experiments research is done to determine how saturated stiff clayey soil responds to a single impulsive load. Models made of saturated, stiff clay were investigated. To supply the single pulse energy, various falling weights from various heights were tested using the falling weight deflectometer (FWD). Dynamic effects can range from the major failure of a sensitive sensor or system to the apparent destruction of structures. This study examines the response of saturated stiff clay soil to a single impulsive load (vertical displacement at the soil surface below and beside the bearing plates). Such reactions consist of displacements, velocities, and accelerations caused by the impact occurring at the surface depth induced by the impact loads
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