Based on the data collected in this study, net irrigationwaterrequirement of main crop in china has been gotten.
根据收集到的资料，计算得出全国主要作物的净灌溉需水量。
2
Rainfall frequency analysis is used commonly to determine probability of irrigationwaterrequirement, and to choose typical years for irrigation project design.
灌区灌溉设计中，常用降雨量进行频率分析来选取灌溉设计保证率及其对应典型年。
3
The waterrequirement and growth in paddy rice were studied under four different irrigation methods and different evaporation and seepage with pot culture.