5767

5382

كارشناسي ارشد

آبياري و زهكشي

اصفهان: دانشگاه صنعتي اصفهان، دانشكده كشاورزي

1389

دوازده،112ص.: مصور،جدول،نمودار

ص.ع.به فارسي و انگليسي

بهروز مصطفي زاده فرد، سيدفرهاد موسوي

محمدزارع مهرجردي، سيدحسين سقائيان نژاد

29/1/90

منوچهر حيدرپور، شمس ا...ايوبي

مهندسي كشاورزي

ID5382

به فارسي و انگليسي: قابل رويت در نسخه ديجيتالي

Comparison of Hydraulic Behavior and Net Erosion of Border Irrigation with Meandering Border Irrigation Hamed Tavakoli Mehrjardi h tavakolimehrjardi@ag iut ac ir Date of submission March 6 2011 College of Agriculture Department of Water Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language Farsi Supervisor s Name and Email address Behrouz Mostafazadeh Fard behrouz@cc iut ac ir Sayed Farhad Mousavi mousavi@cc iut ac ir Abstract Border irrigation is one of the surface irrigation methods which is widely used in agricultural fields Generally at large field slope surface irrigation is characterized by low efficiency with high erosion Border irrigation method is applied in regions where the slope is lower than 1 Although the optimum slope for well performance of this irrigation method is about 0 5 but the farmers apply the border irrigation method on steep fields with two methods of contour borders and meandering borders The contour borders which are constructed on level contours or with a small angle to the contours have nearly the same performance as standard border irrigation But meandering borders which are the subject of this study are used in situation where no contour borders exist Therefore the borders are constructed in the field slope direction and several dikes perpendicular to water advance are made inside each border in such a way that water passes from each dike to another from the corner of each dike In this situation water moves from the upper end of the border to the lower end of the border in meandering form which causes the velocity of advance to decrease which the result is higher intake opportunity time In this way the runoff will reduce and lower advance velocity causes lower soil erosion To date there is no study about the performance of meandering border irrigation under different field slopes This study was performed on an experimental field with a sandy loam soil belonging to Agricultural and Natural Resource Research Center of Yazd in Yazd province To compare the hydraulic performance and erosion of meandering and standard border irrigation methods data were collected for both methods under different slopes of 1 2 and 3 Each border had dimension of 3 5 meters by 35 meters and was irrigated for 60 minutes with inflow discharge of 3 8 liters per second equal to 1 09 liters per second per unit width of the border The results showed that the meandering border irrigation as compared to the standard border irrigation increases the time of advance 27 22 and 44 on field slopes of 1 2 and 3 respectively The advance and recession contours showed that water spread more uniformly over meandering borders as compared to the standard borders The measurements of the outflows showed that the use of meandering border irrigation can save water as much as 32 15 and 8 on slopes of 1 2 and 3 respectively Samples taken from the outflows showed that the net erosion is lower for the meandering border irrigation as compared to the standard border irrigation for each of the field slopes of 1 2 and 3 These reductions on above slopes were 64 80 and 14 respectively In general the use of meandering border irrigation on high field slopes improves the hydraulic performance and controls erosion of border irrigation Key words Meandering border irrigation Advance Recession Runoff Erosion

بهروز مصطفي زاده فرد، سيدفرهاد موسوي

محمدزارع مهرجردي، سيدحسين سقائيان نژاد

منوچهر حيدرپور، شمس ا...ايوبي