主要分析了稻田田间水利用系数的内涵,介绍了目前稻田田间水利用系数的测定方法及其存在的问题,并提出了测定稻作区田间水利用系数的对比实测法。对比实测法依据田面渗漏是稻田的有效耗水,而格田与沟道之间以及田埂的侧渗则是无效的渗漏。测定时,将一个格田四周田埂内侧由塑料薄膜封闭,防止侧渗,另一格田四周田埂保持原状,通过统计灌入二个格田的单位面积灌水量计算田间水利用系数。该方法避免了中间测定造成的累积误差,理论依据充分,实际操作简单,适用于稻作区田间水利用系数的测定。
The connotation of the rice paddy field water utilization coefficient was analyzed, the present de- termination method and the existence questions of the field water utilization coefficient were introduced, and the contrast actual method was proposed. The theory basis for contrasts actual method is that surface leakage is the effective water consumption of rice paddy, and the lateral seepage between the basin and the trench as well as the ridge is the invalid leakage. When concretely measuring, two neighboring basins of the same location ground level and front stubble crops were chosen in upper, middle and lower for three stripe lands in different positions of spot irrigation areas, and all round ridge inside of one basin was sealed by the plastic film to prevent the side infiltrates, and the all around ridge of the another basin was main- tained the status quo. The water volume and the water level were observed after irrigation, field water uti- lization coefficient was calculated by statistic irrigation amount per unit area of two basins. This method a- voided the accumulated error which was caused by the middle determination, and had full theory basis, and the actual operation was simple. This method is suitable for measuring rice field water utilization coeffi- cient.