Multivariable Linear Regression Equation for Rice Water Requirement based on Meteorological Influence

The paper firstly analyzed meteorological influences on rice water requirement referring to temperature, wind speed, air saturation deficit and sunshine hours. Then, it analyzed the other meteorological factors’ influences. Through introduction of natural water surface evaporation factor, a multivariable linear equation with five variables was established for rice water requirement. A five variable linear equation model, FAO56 Penman-Monteith formula and a four variable linear equation which don’t have natural water surface evaporation factor were used to calculate rice water requirement in cold areas. It shows that multivariable linear equation with five variables has a more accuracy, compared with Penman-Monteith formula and four variable linear equation. As a regional empirical formula, the five variable linear equation can be applied in cold area.