| As the lifeline of human beings, water is a material base for social and economic development and an important element of ecological environment. Water scarcity has become a global issue. The water resources in China are insufficient and distributed unevenly. Therefore, it is imperative to maintain sustainable utilization of water resources, promote sound development of ecological environment and develop water-saving irrigation agriculture.The present research is part of the program of the"Research and Demonstration on Integrated Water-Saving Technology of Special Crops in Arid Inland Areas of Gansu"(2007BAD88B07-7) under the project of"Research and Demonstration on Integrated Water-Saving Agricultural Technology", a scientific and technological support program in the"Eleventh Five-Year Plan"period. After a systematic analysis on the status quo and characteristics of water resources in inland river basin—Shiyang River Basin of Gansu, and according to the best crops irrigation models, the present thesis studies and designs intelligent control software system for water-saving micro-irrigation based on GSM digital transmission and accurate remote control. The main findings are as follows:1. The annual surface runoff in Shiyang River Basin is uneven distributed with a declining total amount, and the water resources in its lower reaches, i.e. Minqin Basin, are decreasing greatly year by year. The over pumping of underground water has caused water levels to decline by 0.57 meters per year. The irrigation in Shiyang River Basin is featured by normal and extensive irrigation on large and rough terraces with an irrigation water utilization coefficient from 0.40 to 0.54. The water is over consuming and the water used for farmland irrigation takes a high proportion of 85.9%. The development and utilization of water resources is 159%. Currently, the water consumption amount is much more than the total amount of water resources in the basin. And water resources are utilized for social and economic purposes rather than for natural and ecological protection. All the above facts result in a deteriorating ecological environment and the Minqin oasis will be destroyed eventually.2. The irrigation system for special crops in Shiyang River Basin has been put forward based on the theory of the best crop irrigation system. Meanwhile, management mechanics for irrigation system have been developed with reference to the theoretical models of irrigation systems. 3. GSM network has a wide range of coverage, high anti-jamming ability, and less communication errors, so it has a well extensibility in achieving the communication between acquisition controller of remote data and central control computer, as well as in realizing the real-time monitoring of remote irrigation equipments and collect irrigation data through adopting Short Message Service (SMS) of GSM network. Meanwhile, through introducing adaptive equalization technology and carrying out study on adaptive equalizer based on LMS algorithm, a MATLAB-based simulation model has been established to correct the data distortion produced in GSM network channels so as to ensure the accuracy of data transmission.4. A intelligent control software system for precise water-saving micro-irrigation has been developed, which demonstrates the whole process of intelligent and automatic control irrigation illustrated in charts, process pictures, real-time and historical graphs, and reports, so as to provide reference for users and administrators in decision-making.The inland river basin of Gansu has a vulnerable ecological environment resulting from its insufficient water resources, high water use in agricultural irrigation, extensive irrigation pattern, serious water waste and excessive consumption of water resources. The utilization of remote and intelligent control of precise irrigation would be beneficial for social and economic development and environmental protection, which has a high value if replicated. |
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