不同灌水定额条件下的覆膜开孔蒸发实验研究

Experimental research on evaporation from perforated plastic mulch with different irrigation quotas

在研制了室内蒸发动态观测实验系统的基础上,分析了土表覆膜开孔率和灌水定额不同条件下,蒸发土壤含水率剖面的动态特征。通过累积蒸发量的计算分析,基于Gardner关于裸土蒸发的累积蒸发量与时间关系成正比的理论关系,建立了不同覆膜开孔率和灌水定额影响下累积蒸发量随时间变化的三因素模型,从而成为传统Gardner关系的进一步扩展。在此基础上,进一步分析了覆膜开孔率和灌水定额对相对累积蒸发量和单位膜孔面积累积蒸发量的影响,并得出了相对累积蒸发量和单位膜孔面积累积蒸发量与覆膜开孔率和灌水定额之间的定量函数关系。

On the basis of the development of laboratory equipment from which soil moisture can be measured automatically, the temporal variations of soil water content distribution during evaporation and post evaporation were analyzed, of which, the film hole ratios and irrigation quotas were different. Then after, through calculation and analysis of the cumulative evaporation, the three-factors empirical function of cumulative evaporation determined by evaporation time, open hole ratio and irrigation quota was developed. The function was based on the theoretical relation of Gardner's equation for bare soil evaporation, it can be considered as an extension of the Gardner's equation. Moreover, the influences of open hole ratio and irrigation quotas on relative cumulative evaporation and cumulative evaporation per unit film hole area were analyzed, and the related estimation functions are also provided.