The Research And Application Of Automatic Water System On The Open Channel

Our country is a large agricultural country,73% of the total water resources are used for agriculture. Being lacking of water resources, water shortage has become the largest restricting factors for agricultural development. The effective water-saving measures and actions are significant for the sustainable utilization of water resources. Irrigation district, as an important base for grain production, is the key area to achieve water-saving targets. At present, the irrigation water system is not perfect, and lack of effective water management plan in China. Therefore, in order to realize the scientific allocation of irrigation water and meet the water demand of crop growth, the measurement system with high accuracy, low cost, stable, matched with the type of irrigation channel is the trend for the effective management of irrigation water.Based on the characteristics and development of flow measurement in irrigation district, the Automatic Water Measure System used for multi-sectional types of channels was studied in this paper. The system consists of data acquisition subsystem, information transmission and network subsystem, and monitoring center data processing subsystem. It uses multi-point collection and concentrated statistical analysis way. Firstly, the real-time data of channels water flow are collected and measured by the automatic measuring flow monitoring system. Secondly, the collected data are sent to Master Control Room through the GPRS wireless network transmission system. Finally, the true and reliable data of water consumption which are about irrigation water in the monitoring channels are provided by monitoring center data processing subsystem. In order to obtain more precise flow measure results, irrigation manager can choose different settings in the man-machine dialogue interface according to the different types of channel, such as rectangular, trapezoidal, circular, and U-shaped.In practical application of the system, the paper choose the fourth branch canal of eastern main and the canal of eastern main in Wenyu River irrigation district as study sites. In the same cross section, the system is used to measure water in the same simultaneous with rotating paddle flow meter for comparison. Then through the linear regression model, the flow measurement datas are analied and are test in correlativity. The results indicate that the flow measurement datas's correlation coefficients between this system and rotating paddle flow meter are larger than the threshold 0.8233. And it also shows that the data obtained by the automatic water system has a positive correlation with the data measured by the flow meter. Measuring by the four straight times estimated regression slope (0.907～0.957), it can be seen that the regression line are close to the theoretical slope of the line, which can indicate that the amount of automatic water system of Wenyu River and the results measured by current meter have a similar consistency. And this flow measuring device can be easily to install, the real-time of the water level and the discharge can be measured. Therefore, for the Irrigation District with middle discharge or small discharge, as long as the open channels have such a section which meets the conditions of straight in canal alignment, same in bottom slope, and same in cross-sectional size along the section, the system can be used to measure the water flow accurately.