Determination of Hydraulic Performance of Trickle Irrigation Emitters used in Irrigation Systems in the Harran Plain

Trickle irrigation systems' efficiency depends on system uniformity, which is determined by water discharge uniformity from emitters. It is impossible to produce 2 identical emitters due to manufacturing variations. The manufacturer's coefficient of variance is used as a measure of discharge variations of emitters. In this study, manufacturers' reported discharge rates and coefficients of manufacturing variation (CVm) values were compared with test results for various types of in-line emitters manufactured by 4 different companies in Turkey. A total of 9 drip irrigation lines, comprising 7 non-compensating and 2 compensating emitters, were tested at 50, 100, 150, 200 and 250 kPa pressures. Non-compensating emitter types were not tested at 250 kPa. Compensating emitter exponents ranged from 0.02 to 0.05 while non-compensating emitters' values varied between 0.60 and 0.85. Test results showed that only 1 of the 7 non-compensating emitters and both compensating emitters had flow rates within - 10% of manufacturers' reported values. The t-test between manufacturers' reported and measured mean flow rates at manufacturers' reported nominal operating heads showed that there was no significant statistical difference at the α < 0.05 level. According to ASAE standards, the measured coefficients of manufacturing variation values for non-compensating emitters were not acceptable, although compensating emitters were in the excellent class. Harran Ovas› Sulamas›nda Kullan›lan Damlat›c›lar›n Hidrolik Performans›n›n Belirlenmesi Ozet: Damla sulama sisteminin etkinlii damlat›c›lardan c›kan debinin efldeflliine bal›d›r. Her yonuyle ayn› iki damlat›c›n›n uretimi imkans›zd›r. Yap›m farkl›l›k katsay›s›, damlat›c›lardaki debi deifliminin belirlenmesinde kullan›l›r. Cal›flmada; icten gecmeli damlat›c›lardaki yap›m farkl›l›klar› ile deiflik bas›nclardaki debiler, uretici firma ve test sonuclar› ile k›yaslanm›flt›r. Uretici firmalardan elde edilen deiflik turden 9 damlat›c›n›n befl ayr› iflletme bas›nc›ndaki debileri olculmufltur. Bas›nc duzenleyicili damlat›c›lar 50, 100, 150, 200 ve 250 kPa alt›nda buna karfl›l›k bas›nc duzenleyicisiz damlat›c›lar 250 kPa iflletme bas›nc› haricinde ayn› flekilde test edilmifltir. Bas›nc duzenleyicisiz damlat›c›larda, damlat›c› katsay›s› 0.60 ile 0.85 aras›nda deiflirken bu deer bas›nc duzenleyicili damlat›c›larda 0.02 ile 0.05 aras›nda olmufltur. Uretici firmalar taraf›ndan onerilen iflletme bas›nc›nda test edilen yedi bas›nc duzenleyicisiz damlat›c›lardan yaln›z bir tanesi - %10 s›n›r› icinde kalm›flt›r. Buna karfl›n test edilen her iki bas›nc duzenleyicili damlat›c›da debi deiflimi bu s›n›r icinde kalm›flt›r. Uretici firmalar taraf›ndan onerilen iflletme bas›nc›ndaki ortalama damlat›c› debileri ile test sonucunda olculen ortalama damlat›c› debileri aras›nda yap›lan t-istatistii (α <0.05), onemsiz bir iliflkinin olduunu gostermifltir. ASAE standartlar›na gore, yap›m farkl›l›k katsay›s›, bas›nc duzenleyicisiz damlat›c›larda kabul edilemez s›n›rlar icinde iken bas›nc duzenleyicili damlat›c›larda mukemmel s›n›r icinde kalm›flt›r.