作物需水量预报是灌区土壤墒情预报和灌溉预报的基础。通过对关中泾惠、洛惠和交口抽渭灌区气象资料的分析,用彭曼法计算了历史潜在蒸散量ET_0,利用因子分析法建立了灌区作物需水量随气温、天气而变化的ET_0预报模型,对建立的每月六种模型作进一步的相关分析、符合性、显著性检验,进而由综合评判优选出了适合于灌区ET_0预报的数学模型,开发了作物需水量预报模型建立与优化的通用计算机软件。 Crop water requirement forecasting is the basis of soil moisture forecast and irrigation forecast in irrigation area. Based on the analysis of the meteorological data of Guanghui, Luohui and Jiaokou-Wei irrigation districts, the historical potential evapotranspiration ET_0 was calculated by the Penman method, and the ET_0 forecasting model was established by using factor analysis method. Six monthly models were established for further correlation analysis, consistency and significance test, and then the mathematical model suitable for forecast of ET_0 in irrigation area was optimized by comprehensive evaluation. The general computer software for establishing and optimizing crop water requirement forecasting model was developed .