Influenc And Method Of Irrigation Uniformity

Drip irrigation is one of the most widely used water-saving irrigation technology by theadvantage of high rate of water saving efficiency, high-quality of irrigation. The irrigationuniformity is an important index of evaluating irrigation engineering and the quality ofirrigation. In the actual irrigation engineering project, the irrigation uniformity is affected bymany factors, such as the quality of irrigation water, the quality of emitter, the Workingpressure of emitter, the clogging of emitter, emitter manufacture deviation. Irrigation Systemsshould always have some degree of clogging for some time, which will drive the irrigationuniformity down and directly determines the economic benefits of irrigation engineering andlife.Clogging is one of the most important factors of irrigation uniformity. The ratio anddegree of clogging emitters are important index to evaluate the irrigation uniformity. Theinfluences of working pressure, the number and location of clogged emitters on irrigationuniformity are investigated through turbid water experiment. The ratio, degree of cloggingemitters and the impact on5formulas of irrigation uniformity are studied through the methodof simulation and experimentation. Different irrigation uniformity methods have differentapplicability. The method which can reflect the influence of clogging emitters locationattempted was attempted to propose. The main results show that:（1）The working pressure has no obvious influence on the irrigation uniformity whenthe pressure ranged between4~10m.（2）CU firstly increased and then decreased with the ratio of clogging emitters increase.The ratio and degree of clogging emitters is one of the most important factors of irrigationuniformity. （3）The location had a certain influence on irrigation uniformity while the number ofclogged emitters is not greater than10%, and the highest impact of emitter clogging onirrigation uniformity occurred When the clogged emitters are located at the first one-thirdsection and along the entire line.（4）CU decreases with the increase of the degree of clogging emitters. The reducingtrend of CU is faster when the the degree of clogging is great than60%. The degree ofclogging is one of the most important factors of irrigation uniformity.(5)The irrigation uniformity CU, EU, UWS, DUlqand EUpfirstly increased and thendecreased with the degree of clogging emitters increase. DUhqfirstly decreased and thenincreased with the degree of clogging emitters increase. CU, EUp and UWScan indicate theirrigation uniformity better when the clogging is lighter. When the clogging is serious, EUpwere a better reflection of irrigation uniformityWhen the clogging is in more serious situation,EU and DUlq were a better reflection of irrigation uniformity.(6)Almost all computational methods are pertaining to the the situation that the cloggingis so mild. CU and UWSare ideal for irrigation uniformity under the situation which has vastdifference clogging level or the ratio of high degree clogging emitters is lower. CU and DUlqare ideal for irrigation uniformity under the situation which has vast difference clogging levelor the ratio of high degree clogging emitters is higher. The simulation results had virtually thesame results to fully testify the reliability.(7)The indicators of r(h),dk and dj can respond the location to irrigation uniformity incertain extent, the higher r(h),dk and dj value, the better irrigation uniformity. But they cannot respond the degree of clogging to irrigation uniformity. The indicators have to unite, thehigher CU and r(h)（djk、dij）, the better irrigation uniformity.