土壤点源入渗自动测量系统监测滴头下土壤湿润过程  

Measurement of wetting process of soil under dripper with automatic system for point source infiltration

作　　者：管瑶[1,2] 雷廷武[1] 刘芳芳[1] 董月群[1] 

机构地区：[1]中国农业大学水利与土木工程学院,北京100083 [2]塔里木大学水利与建筑工程学院,阿拉尔843300

出　　处：《农业工程学报》2016年第14期1-7,共7页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家自然科学基金资助项目(50879087);新疆生产建设兵团科技局"十件实事"项目(SJSS201504)

摘　　要：土壤水运动过程是滴灌系统设计和运行管理的重要内容。该研究采用点源土壤入渗自动测量系统,利用计算机可控数码相机和图像识别技术测量滴灌地表湿润面积和土壤湿润体随时间的变化过程。采用正三棱形有机玻璃土箱,设计一系列点源滴灌室内试验,获得点源滴灌入渗过程随时间的变化过程。试验采用3个流量：2、4及8 L/h处理,每个处理设置了3个重复。用数码相机每4 min拍摄一次地表湿润面积,用于计算地表湿润面积随时间的变化过程。同时,在1、2、3、4、6、8、10、12、20、30、40、50、60、70、80、90、100、120、140、160、180 min时刻,在贴在土箱侧面的透明胶片上,手工记录地表湿润面积和垂直湿润锋面随时间的变化过程。由测量系统根据记录的地表湿润面积随时间的变化过程自动计算得到土壤的入渗过程。通过入渗过程,计算得到滴头下地表土壤的湿润面积,由计算得到的土壤入渗率和计算得到土壤的湿润剖面,将计算结果与实测结果对比,检验测量的精度。结果表明,手工测量得到的地表湿润面积都略大于由土壤入渗自动测量系统计算得到的入渗率计算的地表湿润面积。由计算得到的入渗率预测的土壤入渗深度,略大于实测土壤入渗深度。计算得到前者的相对误差为2%-15%,后者的相对误差为1%-8%。说明土壤入渗自动测量系统,能够准确描述点源滴灌地表湿润过程及土壤入渗过程,并能预测不同流量下垂直入渗深度,测量方法可以为滴灌系统的设计提供相关参数。Drip irrigation provides greater efficiency in terms of water usage. It requires adequate design and conscientious management. Soil water movement process is an important content of drip irrigation system design and operation management. Soil infiltration has important impacts on soil water movement and distribution process. Therefore, in this study, the automatic measurement system for point source infiltration of soil was used to measure the wetted areas at soil surface and the wetted depths of soil profile through image recognition technology and computer-controlled digital camera in real time. The digital camera was used to take images of the run-on water advancing in real time before they were processed and then by analysis the wetted areas were determined. According to the wetted soil surface areas, the system automatically computed the soil infiltration rate with the mathematic models outlined in the point source run-on method before the infiltration curve could be displayed on the real-time basis. The soil infiltration measurement system was based on the advancing process of the wetted radius at the soil surface under point source of water supply and based upon the assumption of the ellipsoid-shaped wetted soil body and the principle of water balance. An equilateral triangular-prism soil box of 50 cm long and 50 cm high, which was made of plexiglass, was used in this study for indoor drip irrigation experimental tests, to measure the processes of infiltration and water movement processes. Transparent plastic sheets were pasted on 2 side walls of the soil boxes. The soil materials, with the texture of silty loam consisting of 15% clay, 50.2% silt and 34.8% sand particles, were air-dried before passing through a 2 mm sieve, and then packed into the soil box in 5 cm depth layer at a bulk density of 1.3 g/cm3. The experiments involved 3 dripper discharge rates of 2, 4 and 8 L/h, with 3 replicates. Digital camera that was connected to and controlled by a computer was used to take picture of wetted areas at soi

关 键 词：滴头 灌溉 土壤 入渗性能 点源入渗 地表湿润面积 湿润深度 测量方法 

分 类 号：S152.72[农业科学—土壤学]