Simplified calculating method for cumulative infiltration of furrow irrigation

Key words: 
• two dimensional infiltration /
• cumulative infiltration /
• numerical simulation /
• edge effect

Abstract: Theory analysis and numerical simulation combination method were employed for simplifying numerical calculation process of two-dimensional cumulative infiltration under furrow irrigation. By analyzing the impacting factors of initial water content, water depth, bottom width, slope parameter, soil texture and bulk density effects on edge effect and fitting parameter γ, a relationship between fitting parameter γ and the main influence factors was built and a simplified method for cumulative infiltration of furrow irrigation was proposed. The results show that the initial water content, bottom width and slope parameter have slight influences on the edge effect, however, water depth, soil texture and bulk density have greatly influence on it. Being closely related with water depth, fitting parameter γ decreases with the increase of water depth, but is less sensitive to the initial water content, bottom width, slope parameter, soil texture and bulk density, therefore those impacting factors can be ignored. Based on the references, the reliability of the proposed method in this paper is verified. The results show that the calculated values of the cumulative infiltration agree well with the measured values and simulated values by the HYDRUS. Therefore, it is reliable to estimate the cumulative two-dimensional infiltration with the proposed method under furrow irrigation.