土壤墒情监测技术与PLC自动灌溉系统研究与应用

发布时间：2018-10-24 13:36

【摘要】：以及时获取农田墒情信息、提高农业灌溉用水效率为目标,本文采用大田试验、理论研究、数值分析、系统设计与集成相结合的方法,深入研究了墒情监测技术、水分传感探头的布设位置、土壤墒情监测和灌溉自动控制模型以及系统设计等问题,取得以下主要成果:(1)以烘干法为标准,TDR和FDR法测得土壤含水率的变化趋势一致,TDR法测量精度更高。较TDR法,FDR法的平均绝对误差增大了1.45%,平均相对误差增大了10%,TDR和FDR法与烘干法测量结果的相关系数均高达0.98;采用KMO统计量和球形假设检验Bartlett’s确定了各土层含水量之间存在着一定的相关性,并通过主成分分析和因子分析确定了10cm、30cm、60cm、90cm四个深度埋设水分传感探头是合适的;通过研究0~100cm土壤水分动态确定了冬小麦和夏玉米在0~40cm土层范围内其土壤水分波动幅度最大,且随着深度的增加波动幅度逐渐减少。(2)明确了运用Penman-Monteith和郑州区域多年平均作物系数法计算作物需水量具有较高的精度。在有效降雨量、作物需水量等研究的基础上,根据农田水量平衡原理建立了墒情监测预报模型,并在墒情监测研究的基础上建立灌溉预报模型,灌溉预报模型包括预报灌溉水量和灌溉时间。(3)在土壤墒情监测技术、水分传感探头布设、土壤水分动态变化、作物需水量等相关研究的基础上,设计了系统的数据库、硬件及软件,并实现了集墒情信息采集、墒情信息处理、墒情预报、灌溉预报于一体的土壤墒情监测技术与PLC自动灌溉系统。并将该系统应用于杨桥灌区,其结果表明,整个系统运行较稳定。
[Abstract]:In order to obtain soil moisture information in time and improve the efficiency of agricultural irrigation water use, the method of field experiment, theoretical research, numerical analysis, system design and integration is adopted in this paper to deeply study the monitoring technology of soil moisture. The location of water sensor probe, soil moisture monitoring and irrigation automatic control model and system design, etc. The main results are as follows: (1) the variation trend of soil moisture content measured by TDR and FDR method is the same, and the precision of TDR method is higher. Compared with TDR method, the average absolute error of FDR method increased by 1.45 and the average relative error increased by 10%. The correlation coefficient between FDR method and drying method was as high as 0.98. KMO statistics and spherical hypothesis test Bartlett's were used to determine the water content in each soil layer. There is a certain correlation between the quantity, Through principal component analysis and factor analysis, it was determined that 10 cm ~ (30) cm ~ (60) cm ~ (10) cm ~ (60) cm ~ (90) cm depth water sensor was suitable, and the range of soil moisture fluctuation of winter wheat and summer maize in 0~40cm soil layer was the largest by studying 0~100cm soil moisture dynamics. With the increase of depth, the fluctuation of crop water demand decreases gradually. (2) it is clear that the method of Penman-Monteith and Zhengzhou area annual average crop coefficient has higher precision in calculating crop water demand. On the basis of the research of effective rainfall and crop water demand, the model of monitoring and forecasting soil moisture is established according to the principle of farmland water balance, and the model of irrigation forecast is established on the basis of monitoring and studying of moisture content. The irrigation forecasting model includes forecasting irrigation water quantity and irrigation time. (3) based on the research of soil moisture monitoring technology, soil moisture sensor placement, soil moisture dynamic change, crop water demand and so on, the system database is designed. Hardware and software, and the realization of soil moisture information collection, moisture information processing, moisture forecast, irrigation forecast in one of the soil moisture monitoring technology and PLC automatic irrigation system. The system is applied to Yangqiao Irrigation District. The results show that the whole system is stable.
【学位授予单位】：华北水利水电大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S152.7;S274

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