The Study And Development On The System Of Soil Moisture Automatic Monitoring And Forecasting

Currently, water shortage in the northern areas in China has become more and more rigorous. To solve this problem promoting water-saving irrigation and saving agricultural water strongly are valid methods. Experiments show that scientific water management can save water by 20%.The construction of forecast and monitor system of the soil moisture content can provide a powerful basis for irrigation district water management, drawing up dynamic water using plan and carrying out irrigation district comprehensive water saving strategic target. Using real-time irrigation forecast to instruct the water used by irrigation and making irrigation district to obtain "updating" "proper quantities" of water will be advantageous to save agricultural water and satisfy modern agricultural requirement and have vital significance for sustainable use of water resources. In this paper, QingXu country was taken as a research object; the purpose is to establish an operational simple interface friendly monitor forecast system which can instruct agricultural irrigation. The system development platform is Microsoft Visual Basic 6.0 and SQL integration development platform.The system function mainly realized:1. Automatic collection of soil moisture content information. The county-wide soil moisture content information gather system in Qingxu was establishes and the soil information was collected by global positioning system and fixed monitoring points of soil moisture content.2. Forecast of the water requirement of reference crops. In this article, the water requirement of some reference crops was calculated based on the calculation method from UN Food and Agriculture Organization.3. Forecast of crops' annual irrigation water requirement. In this article water requirement of different crops are obtained during entire period of duration based on the observed history meteorological data and the historical crops water requirement data. The rainfall amounts in different hydrology year were obtained during the entire period of duration based on multi-annual rainfall data. The underground water military of crops are obtained during entire period of duration based on many year underground water data. Then crops' annual irrigation water requirements in different hydrology year are obtained by field water balance equation. 4. Forecast of crop interval irrigation water requirement. Different methods were used according to the time interval length. If the time interval is long, then the historical meteorological data was adopted and the crop interval irrigation water requirement was calculated according to the method as calculating year irrigation water requirement. If the time interval is short, then , the update weather forecast information was adopted and the crop interval irrigation water requirement was calculated according to the method used in real-time irrigation forecast.5. Real-time irrigation forecast. The system calculates the daily crops water requirement based on short-term and medium and long-term weather forecast meteorological information, and then obtains the daily effective rainfall amount and the underground water military supplies quantity according to the empirical formula and then circulates effective water content in moist level. The crops must be irrigated when the effective water content in moist level reduce to certain degree.The system characteristics are:(1) Real-time monitor to farmland soil. The main content of monitor is farmland soil system. The significance of real-time monitor is to gain the farmland soil information dynamic through the real-time fast advanced sensing and real-time information processing technology and to carry on the dynamic appraisal and active surveillance to instruct irrigation scientifically and to improve the quotient of Utilization of water used by agriculture.(2) The use of high-technology. In this system, the absorption of the most advanced practical technology are used including monitor technologies digital communication technologies computer assistance decision-making support long-distance control and so on. (3) The system function is practical and the precision is reliable. (4) The system function can be expanded and the interface is friendly.The system takes instructing water using management in irrigation area as the main starting point. The goal is to enhance the using efficiency of agricultural water and to reduce agriculture water consumption. But as a result of the complexity of the question and the limitation of the method, many aspects of the questions have not been solved and need further research.