The Study On Seepage Controlling Effect Of Irrigation Canal And Irrigation Water Use Efficiency In Shijin Irrigation District

In recent years, droughts have been occurring in many areas of China, which called wake-upfor water crisis and highlighted the importance of water saving in agricultural irrigation. Thecentral committee of the communist party of China has enhanced farmland irrigation wateruse efficiency to an unprecedented important position and has launched a variety of policiesand measures to deal with an appalling waste at the current China’s agricultural irrigationwater. Water saving reconstruction has been upsurged in the irrigation areas all over thecountry, which based on the climate and crop planting characteristics, the irrigation method ofitself. Most of irrigation area irrigate by canals in our country. And most of them existesearious problems such as engineering aging serious disrepair, canals siltation and leakage,lower seepage rate of the engineering systems. ShiJin irrigation area has typical significancein Hebei province even in north China. Thus ShiJin irrigation area was taken as an example inHebei province to solve the common engineering problems and improve the irrigation wateruse coefficiend of the irrigation area by carring out canal water delivery project which ismainly with canal seepage control measures.Along with the advance of anti-seepage technology in China, there emerges many imperviousmaterials which are used in different applicable conditions and seepage control purpose.Comprehense consideration of various factors and related optimal effect of seepage controlexperimental research should be done in order to achieve the optimal effect of seepage controlwhen selecting impervious material was selected.6kinds of anti-seepage lining wereformulated, which were under comprehensive consideration of the material supply, thenorthern climate and the investment benefit and many aspects. Then, they were carried on thefield experiment, for the sake of exploring the anti-seepage effect of their advantages anddisadvantages, and were choosed the anti-seepage lining of the comprehensive benefit of thebest measures for the reconstruction of irrigation canal system. This is the content andpurpose of the paper researching.Typical channels were selected at Shenzhou weiqiao sub-irrigation in ShiJin irrigation districtto conduct water loss field experiment, by reading a large number of books and learningliterature about various aspects such as canal seepage control, water conveyance channel lossmeasurement at home and abroad, the irrigation water use efficiency effectively and statistics and so on. The results were concluded as following:(1) At the canal seepage control measures, seepage control materials with different actionsand characteristics were selected considering three different aspects: the materials of seepageprevention, construction technology and the expansion joints according to the characteristicsof irrigation area. Then an optimizing design was made in accordance with diffierent principle.It means that in order to study the presence or absence to the canal seepage prevention effectof insulation board or geotextiles or concrete. It should make the factor as the only diffierentone to study and others are same. Finally, it formed six different composite anti-seepagelining.(2) Experiments were made in studying the anti-seepage effect of the experimental canals.The experiments included dynamic water method (including traditional dynamic watermethod and canal downflow method) and hydrostatic method. Beside, the test involved otherrelevance related validation tests between the different instruments, different test method(traditional dynamic water method and canal downflow method) and evaporation from watersurface and so on. Simultaneously, loss conveyance experiments were made by traditionaldynamic water method on3diffident type canals, the earth canal, running years oftrapezoidal canal and parabolic canals, which were compared canals.(3) Large amounts of test data had been obtained by doing field experiments and analyzed inthis paper. Water loss coefficient was used as parameter to compare the unlined with liningcanals, the trapezoidal with parabolic canal. Importantly, the conveyance loss of the6kindsof compound anti-seepage lining forms were compared on the different periods that beforeand after freezing of the same form and the different forms during the same period.In addition, hydrostatic method, which accuracy is higher, was used as a control test to thedynamic water method. Leakage intensity was used as parameter to compare the water lossrate and other relations between it and water depth of6kinds of compound anti-seepagelining forms. Based on the above, a profound analysis of amount of water saving were gaven,the effectiveness of investment and land-saving, and irrigation application efficiency of theforms. Finally, considering all factors mentioned above, an anti-seepage lining form wereidentified which had the optimal comprehensive benefit, to provide the most suitable lining inthe canal seepage control measures for the future transformation on economy of canal watercousumption.