【摘要】 土壤水分的精准获取对农田灌溉水有效利用系数测算至关重要。为进一步检测土壤墒情自动监测传感器的准确性,进行野外田间对比观测实验,采用烘干法与传感器测量数据对照,以检验设备的野外测量精度是否满足农田灌溉水有效利用系数测算的要求。结果表明:土壤墒情自动监测传感器相对误差均小于±10%,满足土壤自动监测和农田灌溉水有效利用系数测算的要求。调研北京市怀柔地区水资源及农业灌溉情况,选取了全区灌区内47个站点为测算样点,采用首尾测算法对被测区域内的农田灌溉水有效利用系数测算,结果分别为0.76和0.68。野外田间观测实验和实际的田间监测应用表明:选取的传感器设备对实际的野外田间应用适应性好、精度优于国标,且安装维护都十分简单方便。更多还原

【Abstract】 The effective utilization coefficient of farmland irrigation water is one of the most important indicators for implementing the most stringent water resources management system and implementing national water conservation actions. It is crucial that the accurate measurement of soil moisture for calculation of effective utilization coefficient of farmland irrigation water. Firstly, the water resources and agricultural irrigation in Huairou District of Beijing were investigated, and the whole area was determined to be well irrigation district. According to the layout of Huairou District agricultural production and the actual distribution of well irrigation district, 12 sample irrigation districts were selected, and the location of 47 measured typical field in the whole irrigation district were determined. Secondly, the existing soil moisture detection method was analyzed, and a new type of soil moisture automatic monitoring sensor was adopted. The analog sensing circuit, A/D conversion and wireless transmission circuit of the sensor was integrated designed, and data of the sensor were wirelessly transmitted to cloud server platform through GSM/GPRS. Multi-depth time division multiplexing detection technology was adopted by sensor detection circuit, signal interference caused by multiple high frequency circuits was reduced. The applicability and accuracy of the sensor for automatic monitoring of soil moisture were analyzed, a comparative observation experiment was carried out in the field. Flat and far away from the ditch was selected as the experimental site. the results of manual soil sampling and drying method were synchronously compared with the measured data of the sensor. The comparative observation results show that the relative errors of the measured value of the automatic soil moisture monitoring sensor and the drying value of the artificial soil are all less than ±10%, the absolute error of the measured value is about 1% in the case of drought and about 2% in the case of high humidity. The accuracy of the sensor is better than the national standard. It meets the accuracy requirements of soil moisture monitoring and can measure the effective utilization coefficient of farmland irrigation water. Finally, the methods for calculating the effective utilization coefficient of domestic farmland irrigation water of recently years had been analyzed. The head-tail calculation method was used to calculate the amount of irrigation water per mu of irrigation, and the amount of water that can be absorbed and utilized by the crops is directly calculated from the water source. The ratio of total irrigation water used was not determined by the loss of irrigation water during transportation, water distribution and irrigation.Only the parameters such as soil moisture content, soil bulk density and water consumption of planting crops before and after irrigation were measured.Using the soil moisture monitoring data of sensor from the cloud platform, and considering weather and irrigation information, the amount of net irrigation water used in each sample irrigation districts was calculated and counted. According to the field research data, the amount of water used for irrigation was estimated. The effective utilization coefficient of farmland irrigation water in the irrigation area of micro-irrigation type and pipeline water irrigation type in Huairou District of Beijing was calculated, and the results were 0.76 and 0.68, respectively.更多还原