青海省大峡灌区典型地块作物耗水系数研究

Study on Crop Water Consumption Coefficient of Typical Plot of Daxia Irrigation Area in Qinghai Province

采用引排差法和最大蒸发量法对青海省大峡灌区典型地块耗水系数进行计算研究。在典型地块设置了2个斗渠引水口和6个退水口,并对其春灌期流量进行监测。同时在典型地块内设置5眼地下水监测井,用于计算地下退水量。在综合考虑地表退水和地下退水基础上,采用引排差法计算耗水系数;同时利用最大蒸发量法计算耗水系数,对引排差法进行验证。结果表明,采用引排差法计算得到的大峡灌区典型地块春灌期耗水系数为0.48,采用最大蒸发量法,计算得到耗水系数为0.49,两种方法计算得出的耗水系数非常接近,说明在试验区耗水系数计算上,最大蒸发量法可以对引排差法进行较好的验证。

Diversion and drainage method and the biggest evaporation method were used respectively to calculate crop water consumption coefficient of typical plot of Daxia irrigation area in Qinghai province. Two lateral canal irrigating gates and six waterspouts were set up in the typical plot and water flow was monitored during the spring irrigating period, and five groundwater wells were also set up to monitor groundwater. In consideration of the surface water and underground water drainage, diversion and drainage method was used respectively to calculate crop water consumption coefficient. The biggest evaporation method was also used to calculate crop water consumption coefficient, to verify the diversion and drainage method.The results showed that crop water consumption coefficient calculated by diversion and drainage method and the biggest evaporation method were 0.48 and 0.49 respectively. The results were so closely, which indicated that the biggest evaporation method could lead better validation to diversion and drainage method for crop water consumption coefficient calculation in the scope of the study area.