摘要
根据新疆阿克苏农田生态系统国家野外科学观测研究站1990-1996年裸地潜水蒸发及水面蒸发资料,提出了计算裸地潜水蒸发量的反S型曲线模型,同时采用迭代法对模型进行了非线性拟合,并建立了模型中参数与水面蒸发的定量关系。该模型结构合理,较全面地反映了潜水蒸发的变化规律,克服了当大气蒸发力较大时过高估计潜水蒸发量、潜水蒸发随水面蒸发的增大而线性增加的缺点,计算精度较高,可供相似地区参考使用。
Phreatic evaporation from bare soil is a process that transfers water from phreatic zone to unsaturated zone,and further to air through soil evaporation. It is of great importance in different field studies such as hydrology,meteorology,and agriculture to evaluate the water balance and thermal behavior of the soil. Evaporation from soil surface causes not only the loss of water resources but also soil salinization problem. From 1990 to1996,the experiment of phreatic evaporation from bare soil was carried out at the Aksu National Field Research Station of Agro-ecosystems（ANFRSA）（80o51′E,40°37′N）,Aksu Prefecture,Xinjiang,China,which lies in the new oasis of an alluvial plain where the 3 main headstreams of Tarim River meet. The soil is silty loam. A set of simple and convenient lysimeter with the sectional area of 1 m2 were setup in 1990. In these lysimeters,5 different phreatic depths i.e.,0.25 m,0.75 m,1.25 m,1.75 m,and 2.25 m with 2 duplications were arranged to observe the evaporation from bare soil once every 5 days. Water surface evaporation is measured by a 20-cm evaporimeter at 20∶00 Beijing Time every day. The daily water surface evaporation value is calculated based on the water balance law. Based on observations of phreatic evaporation and Pan-evaporation,monthly phreatic evaporation rate and Pan-evaporation rate of every year were calculated firstly,and then the 7 years averaged monthly phreatic evaporation rate at different phreatic depth and Pan-evaporation rate were calculated. Based on these data,the inverse＂S＂model for calculating the phreatic evaporation on bare land is presented. Iteration method is applied for the nonlinear regression. The relationship between parameters of this model and water surface evaporation is established. The results show that this model can more exactly reflect the change of phreatic evaporation with the reasonable construction,overcome the shortcomings that the phreatic evaporation is overestimated when atmosphere evaporation capacity is higher,and t
出处
《干旱区地理》
CSCD
北大核心
2016年第2期233-239,共7页
Arid Land Geography
基金
国家自然科学基金-新疆联合基金面上项目(U1303181)
关键词
裸地潜水蒸发
反S型曲线模型
非线性拟合
phreatic evaporation from bare soil
inverse＂S＂model
nonlinear regression
