Research On Discharge Mesuring System In Large And Medium-sized Irrigation District Along The Liyun River

Agriculture is our country’s water conservation,and agricultural water consumption accounts for more than 60%of the total water consumption.Due to the increasing of population,the development of industry,the acceleration of urbanization and the increasing use of non-agricultural water,higher requirements have been put forward to control the irrigation water and improve the water efficiency of irrigation.Discharge measurement was essential to the irrigation management and water fee collection of the irrigation districts.Effective monitoring of water consumption in irrigation areas is more and more urgent and the monitoring requirements are getting higher and higher.In this paper,by considering the actual situation of irrigation districts along the Li Canal,taking Gaoyou irrigation district as the main research object,collecting available information of canal system in irrigation area,choosing the most appropriate discharge measuring devices for different lateral canals,reasonable layout,and developing a set of measure water information system for real-time data acquisition in irrigation area.The main research is as follows:1.The development process of the discharge measurement technique was systematically summarized,and the recent advances on the research of the weirs,flumes,flow measuring instrument and automatic measuring technique were reviewed.2.The characteristics of several kinds of commonly used discharge measuring devices were summarized.On this basis,a method of selecting water measure equipment for small canals based on analytic hierarchy process(AHP)was proposed.The selection of devices is the target layer,the flow measuring range,submergence degree,measuring accuracy,construction cost,flow measurement and management convenience are the criterion layer,and the five commonly used discharge measuring devices are the scheme layer.The analysis shows that for canals in large and medium-sized irrigation districts in the south of China,the optimal order of discharge measuring device is separate-flow meter,cylinder flume,long throat flume(measuring weir),cutthroat flume and Parshall flume.The optimal result has some directive value for the selection of equipment in irrigation districts mentioned above.3.There are 9 main canals,127 branch canals and 3250 lateral canals in Gaoyou irrigation district,to ensure the reliability of water balance analysis,the most suitable discharge measuring devices and equipment must be layout according to various characteristics of different irrigation districts.The main canals still select canal structures for flow measuring;The 70%of the branch canals use distribution gates,and 30%choose the Doppler ultrasonic flow meter;The typical ditches adopt electronic remote-reading water meter,and the rest use traditional water meters.4.With Delphi7.0 as the development environment,the docking of Delphi and SQL sever is completed through ADO control,and a user-oriented management module and query system for irrigation water consumption is established.Including five modules:Account Login,Data Manager,Historical data module,water efficiency of irrigation module,and Modify password module.It can realize the organization,statistics and management of the total water consumption in the irrigation districts,and easy operating,which greatly saves resources,improves work efficiency,and has good practicability and stability.