Study On The Monitoring Of Rice Water Requirement And The Model Of Irrigation Forecast In Chuanhang Irrigation District

Large water management in irrigation district in our country at this stage are widespread the problems such as the low level of management, the low utilization rate of water resources, the low utilization efficiency of water resources. To solve these problems, the researching on the monitoring of rice water requirement and the model Irrigation forecast has important significance in improving the level of water management, improving the utilization efficiency of water resources, realizing the scientific water management in irrigation district.This paper study on Chuanhang irrigation area, through the method which is combined with investigation analysis and demonstration test, monitoring the different rice water requirement information, calculating the rice water requirement in Chuanhang irrigation by the P-M equation, combining with the soil moisture information, setting up the system of monitoring the information of rice water requirement in irrigation, setting up the model of irrigation forecast. The main results were as follows:(1)A monitoring system which is established as the information of the rice water requirement in the lateral canal which is divided into the unit of irrigation management.The information of the rice water requirement mainly include the information of meteorological, the information of rice physiological growth parameters, the information of farmland soil moisture.(2)Setting up the transmission way which transmit the information of rice water requirement online by the GPRS module, realizing the information of rice water requirement which is transmission and monitoring of a wide range in the Chuanhang irrigation area.(3)The actual water requirement of rice crop in Chuanhang irrigation is 719.69 mm by the P-M equation, in the whole growth period of rice, the daily water requirement is 6.41 mm/d in tillering stage, the daily water requirement is 6.5 mm/d in jointing-booting stage, the daily water requirement is 5.33mm/d in flowering period. The daily water demand is 5.94 mm/d in rice three stages.(4) Establishing the diagnostic index of the water shortage by canopy temperature of rice, when the crown air temperature difference is critical range from-0.7-1.5, it need to irrigate when the crown air temperature difference is greater than critical range, the soil moisture content is less than the lower limit of soil water cut at this time.(5)Rice canopy temperature and great temperature trends are basically identical at rice different stages of different times spend.The average canopy temperature is lower than the average temperature of the day in filling period. The average canopy temperature is higher the average temperature of the day in mature stage.(6) The soil moisture indicators for the prediction of irrigation time, during tillering, sunning, jointing-booting stage, flowering and fruiting period of soil moisture and lower respectively 32.44%,28.26%,35.26%,30.8%.(7) Establishes under the different irrigation way separately the irrigation forecast model, rains continually when irrigates the forecast model, time the forecast rainfall irrigation forecast model, take distributional farmland hydrology model as foundation distributional irrigation forecast model.