计算与预报农田蒸散量的数学模型研究

本文分析了蒸发力、土壤有效含水量和作物叶面积指数对农田蒸散量的影响,分别找出了土壤供水充足和供水受限制时的农田蒸散量及其影响因素之间的关系。以水量平衡方程为基础建立了计算和预报农田实际蒸散量的数学模型。本文还提出了计算蒸发力的半经验公式。最后,分析了农田实际蒸散量对蒸发力、初始土壤含水量和叶面积指数的敏感性。

A Study of the Mathematics Model for the Computation and Prediction of Evapotranspiration form the Farmlands

The effects of evaporation potential,available soil moisture and leaf area indexes on the evapotranspiration from the farmlands was an- alysed.On the basis of which the relationspip between evapotranspira- tion from the farmlands and other factors was found out when soil moisture supplies were available or restricted.Based on water balance equation,the mathematics model for the computation and prediction of evapotranspiration from the farmlands was established.This paper pres- ented a semi-empirical formula for the calculation of evaporation pote- ntial,and at the same time,the sensitivity of actual evapotranspi- ration from the farmlands to evaporation potential,the initial soil moisture content and leaf area index was also analysed.