عنوان

ارزیابی و پیش بینی خصوصیات هیدرولیکی خاکهای مختلف با استفاده از مدل های ریاضی موجود

Number

‭۲۰۷۳پ‬

.Language of Text, Soundtrack etc

per

Title Proper

ارزیابی و پیش بینی خصوصیات هیدرولیکی خاکهای مختلف با استفاده از مدل های ریاضی موجود

First Statement of Responsibility

/حسین رضایی

Name of Publisher, Distributor, etc.

تبریز: دانشگاه تبریز

Specific Material Designation and Extent of Item

‮‭۱۷۹‬ ص، جدول، نمودار، عکس، لوح فشرده‬

Text of Note

چاپی

Text of Note

واژه نامه بصورت زیرنویس

Text of Note

کتابنامه ص.: ‮‭۱۷۵-۱۷۹‬

Dissertation or thesis details and type of degree

دکترا

Discipline of degree

علوم و مهندسی آبیاری - آبیاری و زهکشس

Date of degree

‮‭۱۳۸۳/۰۹/۱۲‬

Body granting the degree

تبریز: دانشگاه تبریز

Text of Note

در این تحقیق منحنی مشخصه آب خاک با مدل های آریا و پاریس ،آریا و همکاران و تایلر و ویت کرافت شبیه سازی شده و با منحنی مشخصع اندازه گیری شده و مقایسه گردید.در برابر مقدار و شدت جریان آبهای زیر زمینی و نیز انتقال مواد آلاینده در محیط های متخلخل ارزیابی دقیق ضرایب هیدرولیکی ( هدایت هیدرولیکی( ) ‮‭k‬ وپخشیدگی هیدرولیک( )‮‭(D‬ نقش اصلی را ایفا می کند .

Text of Note

Soil moisture characteristic curve (SMCC) is the most important physical characteristics of soil in the design of irrigation and drainage systems, determination of hydraulic conductivity, and transfer of contaminants in porous media. Direct method in the derivation of SMCC is often costly and time consuming. Hence, theoretical and empirical models are often used to simulate SMCC. The main targets of the present study were to compare the actual SMCC with the prediction from different Models of Arya and Paris (1981), Arya, et. al. (1999) and Tyler and Wheatcraft (1959), and to modify the simulation results with the scale parameter for different types of soils. The input data for these models are particle-size distribution and scale parameter. In this study, nine different series of soil types were examined to represent various soil textures ranging from Loamy Sand to Clayey. Results indicated that the simulated SMCC are significantly different from the measured SMCC, and the scale parameter for each type of the soils is the major factor in the discrepancies. Hence, the scale parameter plays a major role in the simulation process. Scale parameter, ? , is generally evaluated by a relationship in the form of ?i=(a+blog(Wi/Ri3))/logni. In the present study, empirical coefficients a and b have been determined for different soil types. Results indicated that with a=log(3/4??s)) and b=1.0156e-0.953, the scale parameter (?) could be well reproduced regardless the soil texture, thereby, the simulation of SMCC could be accurately possible. The simulated water contents from SMCC are to be in good agreements with the measured ones, and the mean relative error is rated to be about 0.79 in different soil textures. Hydraulic coefficients of a porous media such as hydraulic conductivity K(?), and diffusivity D(?), play major role in the evaluation of groundwater flow and the transport of pollutant. Successful ground flow evaluation depends on the accurate determination of these hydraulic coefficients, particularly in unsaturated condition. It is a hard and time consuming task to measure K(?) and D(?), and measurements usually take place at a moisture range close to the saturation level. The evaluation of K(?) and D(?) is possible by the use of predictive models using only measured soil moisture characteristic curve as input data. At present study, pressure plates apparatus were used to build up the soil moisture characteristic curve for undisturbed samples of nine different soil textures. The volume of outflow was measured with respect to time, and the total volume of released water was measured at the end of each experiment at any given imposed pressure (0.1 to 1.5 Mpa). on undisturbed soil samples. Based on the Richard's equation A simple equation is introduced for the estimation of K(?) and D(?). Applications of the models by Mualem; van Genuchten et. al ; Burdine; Green and Corey; and Gardner resulted in a wide spread prediction of K(?) and D(?) values in nine different soil textures. Therefore, the choice of the most reliable model would be a challenge. In the present study, the outer limits of simulates values of K(?) and D(?) from different models were considered as permissible range of prediction errors. Then, the results from the proposed method were compared will that from the models. It is considered that, the proposed method for determination of K(?) and D(?) provides a reliable tool for the selection of the best simulation model.

Hydraulic conductivity

Soil moisture ch

Models of Arya and Paris

رضایی، حسین

نیشابوری، محمدرضا، استاد راهنما

سپاسخواه، علیرضا، استاد راهنمای همکار

دادمهر، رضا، استاد مشاور

یاسی، مهدی، استاد مشاور همکار

Public note

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