نوع مقاله : مقاله پژوهشی
نویسندگان
1 دانشجوی دکتری آبیاری و زهکشی، گروه مهندسی آب، دانشکده کشاورزی، دانشگاه ارومیه
2 استادیار گروه مهندسی آب، دانشکده کشاورزی، دانشگاه ارومیه
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Characteristics of a produced soil wetting front by a point source plays considerable role in
the efficiency of drip irrigation. The Shape of wetting pattern depends on various factors such as
soil texture and layers, soil structure and emitter discharge. The purposes of this study include
evaluation of wetting front advancement and comparison of HYDRUS 2D model simulations of
surface drip irrigation with measured data on the field and estimating the depth of stored water in
soil layers. In this study, a drip irrigation using T-Tape method was carried out on a sandy-loam soil
at four different irrigation times (2, 4, 8 and 24 hour).Volumetric water content of soil samples were
measured by gravimetric method. Evaluation of the simulated and measured soil water content was
performed by using adjusted coefficient of correlation (R2), relative error (RE) and normalized root
mean square errors (NRMSE) values. Based on the results, the NRMSE value for water content of
soil profile with radial distances of zero and 10 (cm) from the dripper location, was calculated in the
range of 10 to 15 and 7 to 14 percent, respectively. Also, the RE and average R2 values for the same
water content were calculated in the range of 8 to 16 and 7 to 13 percent and 0.96 and 0.95,
respectively. The results indicated that the HYDRUS 2D model could predict the soil water content
with appropriate precision. Also, three scenarios including 1-double discharge increment (Q2), 2-
soil bulk density increment (S1) and 3- soil bulk density reduction (S2), were evaluated for
investigating the amount of water stored in the soil profile. The results showed that the effect of soil
bulk density parameter (S1 and S2) on the amount of stored water depth is greater than the impact
of discharge (Q2). So as a reduction of 5% in bulk density, on average, increased the stored water
depth in the soil profile the rate of 69.85 percent, while this enhancement for the 2-fold increase in
the discharge scenario was 41.91 percent.
کلیدواژهها [English]
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