Earth face evapotranspiration remote sensing inversion method and system based on MODIS data

Abstract

The invention relates to an earth face evapotranspiration remote sensing inversion method and system based on MODIS data. The earth face evapotranspiration remote sensing inversion method comprises the following steps that (1), a research area is confirmed, relative MODIS data porducts in the research area are achieved and pretreated; (2), a scatter diagram of space change information is built by the utilization of the pretreated MODIS data products, a remote sensing inversion of pixel sized surface evaporation ratio EF is conducted; (3), according to the relative MODIS data products, remote sensing inversions of pixel sized surface net radiation Rn and soil heat flux G are conducted; (4), according to the surface evaporation ratio EF, the surface net radiation Rn and the soil heat flux G, a remote sensing inversion of pixel sized earth face evapotranspiration LE is conducted. The earth face evapotranspiration remote sensing inversion method only needs to input the MODIS data, the problem that the current evapotranspiration remote sensing inversion usually needs more ground observation data to assist is solved, and the earth face evapotranspiration remote sensing inversion method can be used for the evapotranspiration remote sensing inversion in the area with no data or with few data.

Description

technical field [0001] The invention relates to a surface evapotranspiration inversion method and system, in particular to a surface evapotranspiration full remote sensing inversion method and system based on MODIS data. Background technique [0002] Land surface evapotranspiration is an important part of the surface energy balance and water balance, and directly affects the water and heat transfer in the soil-vegetation-atmosphere system. In research fields such as agronomy, hydrology, meteorology, etc., such as farmland irrigation and farming system management at the field scale, surface water and groundwater prediction and estimation at the regional scale, atmospheric circulation and climate change simulation at the global scale, etc., evapotranspiration plays an important role. plays an important role. The solution to almost all water problems is inseparable from the study of evapotranspiration. [0003] Traditional evapotranspiration estimation methods are mostly base...

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Problems solved by technology

Clearly, this correction for aerodynamic impedance cannot be performed in all cases, severely limiting the application of the one-source model

In addition, sensor calibration, atmospheric correction, and the determination of surface emissivity will all have a fatal impact on the one-source energy balance estimation method that relies on absolute surface temperature or surface temperature difference

While one-source surface energy balance models can provide reliable estimates of surface sensible and latent heat fluxes, they generally require field corrections, making them difficult to apply to widely varying underlying surface conditions

[0005] Although the two-source energy balance model has certain advantages over the one-source energy model in terms of model structure and model parameterization (such as reducing the sensitivity to input data and considering the influence of satellite observation geometry, etc.), it still requires a large number of close Surface-observed meteorological and vegetation data are used as input, limiting its application to data-free or data-poor regions

[0006] In order to overcome the problem that the conventional surface meteorological and vegetation data are difficult to obtain at the satellite pixel scale encountered by the one-source and two-source energy balance remote sensing evapotranspiration inversion models, we use MODIS remote sensing data to develop a full remote sensing inversion of surface evapotranspiration. play method

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