Farmland evapotranspiration short-term prediction method

Abstract

The invention discloses a farmland evapotranspiration short-term prediction method, which relates to the technical field of crop monitoring and comprises the steps of determining a prediction reference date and a short-term prediction date; obtaining a reference crop evapotranspiration ET0 of the prediction reference day by using a PM method; obtaining the actual crop evapotranspiration ETc of thetarget farmland prediction reference date by using a vorticity related system; calculating a crop coefficient Kc of the target farmland for short-term prediction; predicting a reference crop water demand ET '0 of each short-term prediction day by adopting a Hargeavies-Samani model; obtaining evapotranspiration ET'c of each short-term prediction day; calculating a historical experience correctionparameter alpha; and calculating the predicted evapotranspiration ET ''c of each short-term prediction day of the target farmland to complete the short-term prediction of the evapotranspiration of thefarmland. The method is higher in application value, high in prediction precision and good in stability for farmland evapotranspiration short-term prediction, and a scientific basis is provided for farmland moisture management in a plain region in the future.

Description

technical field [0001] The invention relates to the technical field of crop monitoring, in particular to a short-term prediction method for farmland evapotranspiration considering dynamic changes of crop coefficients and historical experience. Background technique [0002] The evapotranspiration process is an important part of the terrestrial hydrological cycle, and the evapotranspiration (Evapotransspiration, ET c ) has important guiding significance for irrigation planning and regional water resource allocation. Accurate prediction of evapotranspiration can save irrigation water to a certain extent, especially in arid and semi-arid areas where agricultural water consumption is large and crop growth is highly dependent on irrigation. Therefore, in order to better manage crop irrigation water consumption and improve crop water use efficiency, there is an urgent need for crop ET c Make accurate predictions. [0003] The commonly used methods for forecasting evapotranspirat...

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Problems solved by technology

[0006](1) Fixed or simple difference Kc recommended by FAO-56, suitable for longer period ET0 prediction, but for the prediction of short-term ET0 the applicability value is low, and the basic crop coefficient curve in the crop coefficient method is only composed of three nodes and then linear difference, which can deal with the crop growth process Simplified, which will cause a large deviation;

[0007](2) The historical empirical laws of ETc are insufficiently considered. If only model estimation is used, it is easy to cause extreme deviations and the stability is relatively low. Difference

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