Soil Freezing-Thawing Information Acquisition Method And Sensor Research

With the seasonal freezing and thawing soil in northern China as the object of the research, this paper develops the soil freezing and thawing information detection system with independent intellectual property, and based on the study of data processing and analysis method, it carries out the research on variation rules of moisture and temperature in the process of the soil freezing and thawing.The specific contents are as follows:(1) Based on the principle of moisture measurement of soil as well as the temperature and measuring depth of soil, in this paper, the author has developed a soil freezing and thawing information measuring sensor which integrates a high-speed processor. To make the system more intelligent, the sensor uses the distributed control algorithm and CAN communication protocol.(2)To optimize the design of sensor, the author has used a tubular shape and the grinding tool treatment, which greatly simplifies the process of installation and operation as well as reduces damage to the original soil, and finally improves the practical value.(3) Aiming at the particularity of information collection on soil freezing and thawing, the author has developed two sets of data collection and transmission system, which were carried on the long-term test observation in the laboratory and field and fully verified the stability and the real value of the system. Besides, the large amount of experimental data has laid a solid foundation of the analysis of the rules about how water and heat of soil transport. It also provides a measurement tool for the related industries.(4)Through a complete freezing and thawing period access to information in experimental base XiaoTangshan, ChangPing District in Beijing, a seasonal frozen soil water thermal coupling model on Beijing has been built. According to the analysis on field measurement results, we can know the surface temperature changes with the temperature in the air. However, deep soil temperature changes relatively slowly, and the deeper the soil the longer lag time, which guarantees the soil a heat-preservation property. In the freezing and thawing process, the surface soil temperature changes relatively more obvious and quickly, while the figure for deep soil changes relatively slowly.In summary, this study completes the information acquisition methods about freezing and thawing soil, measuring sensor and the model of freezing and thawing soil in Beijing area, which is helpful to promote the sustainable development of agriculture and forestry in science and technology.