Showing 3 results for Border Irrigation
Sayed Farhad Mousavi, Behrouz Mostafazadeh, Shokrollah Absalan,
Volume 2, Issue 4 (1-1999)
Abstract
This study aims to evaluate the present management of border irrigation systems applied to wheat, alfalfa and sugar-beet farms in Boyer-Ahmad and Gachsaran cities in Kohgiloyeh and Boyer-Ahmad Province. Experimental farms included 8 alfalfa farms, 5 wheat farms and 5 sugar-beet farms. The experiments were conducted at different growth stages of plants and customary borders with prevalent dimensions, slopes, and management practices. The relationship between management allowable deficit, moisture deficit before irrigation, and infiltrated depth indicated that in most cases either “deficit irrigation” or “stress irrigation” had been applied. This type of irrigation has positive effects on water use but negative effects on supply of required soil moisture for plants. In the first to third irrigations, measured application efficiencies ranged from 40.8% to 100%, 52.2% to 100%, and 61.1% to 100%, respectively. Graphs of advance, recession, and ideal recession showed the effects of border slope and length on inflow cut time and uniformity of water distribution. Water infiltration curves showed the amount of deficit irrigation. The results showed that weak irrigation management is the result of three parameters: lack of knowledge on the part of farmers about soil moisture conditions and correct time for irrigation, weak irrigation scheduling, as well as an imbalance between available water supply and irrigation requirements which leads to wasting water and reduced irrigation efficiency.
S. A. Mohseni Movahed, M. Akbari, P. Salehi Moghadam,
Volume 17, Issue 66 (2-2014)
Abstract
As pressurized irrigation is not possible for all circumstances, the use of modern techniques in surface irrigation is essential. In this paper, BISEDOM, a new mathematical model for evaluation, design and optimization of border irrigation is introduced. The effects of weighting coefficients of indicators are investigated based on the potential to improve and the most appropriate weighting scheme in optimization process is presented. In this model, volume balance equations for hydrodynamic simulation and SA method for optimization steps are used. Due to the nature of the SA, its parameters are determined by the method of sensitivity analysis. In this model, evaluation of different combinations of decision variables (inlet flow, length, width and slope of the strip) and consequently the performance of irrigation efficiencies reagent strip in an objective function is possible. Finally, the results indicate that the proposed method for weighted indicators has significant effects on improving performance of border irrigation. Model validation results in three parts of design, evaluation and optimization in comparison with SIRMOD and asymptote method showed that the results are very close to each other. The results also indicate that the proposed model has a good efficiency in comparison with other existing models especially for optimization purposes.
H. Ebrahimi Golbosi, E. Fazel Najafabadi, M. Shayannejad,
Volume 28, Issue 2 (8-2024)
Abstract
Surface irrigation is one of the most common irrigation methods. Due to the low efficiency of surface irrigation, water loss is significant in this system. It is necessary to know the characteristics and coefficients of water infiltration rate in the soil for accurate and adequate planning of surface irrigation. One of the equations used in this field is Phillip's infiltration equation. In this study, the infiltration coefficients of Phillip's equation and Manning's roughness coefficient in border irrigation are determined based on the comparison of the actual advance curve with the advance curve calculated with the dynamic wave model, and the results were compared with the double cylinder method and the two-point method of Ebrahimian et al. (5). The actual infiltration volume was obtained from the difference between the inlet and outlet volumes. The error of the mentioned method in calculating the infiltration volume was 5.53%. Meanwhile, the errors in the double cylinder and two-point Ebrahimian (5) method were 59.62% and 19.08%, respectively. In heavy soils, the longer the length of the border increases, the method is more accurate in estimating Philip's coefficients, while in light soils, the advancing time, which in addition to length is a function of permeability, input discharge, and the slope of the bottom of the bed is increased, the accuracy of the method in estimating Philip's penetration coefficients is increased.
