Evapotranspiration remote sensing inversion method and application based on two-dimensional space of reflectivity-vegetation coverage

Abstract

The invention belongs to the technical field of the earth surface evapotranspiration remote sensing estimation, and relates to an evapotranspiration remote sensing inversion method and the applicationbased on the two-dimensional space of the reflectivity-vegetation coverage. The method comprises the steps of: obtaining the relevant data of a target area at the pre-set time scale; determining theprinciple and the definition of the evapotranspiration remote sensing inversion method based on the two-dimensional space of the reflectivity-vegetation coverage, and a variation law of the evapotranspiration ratio in the two-dimensional space of the reflectivity-vegetation coverage; according to the long-term sequence remote sensing short-wave infrared reflectance data and the vegetation coveragedata, determining dry and wet edges of the two-dimensional space of the reflectivity-vegetation coverage, and constructing the two-dimensional space of the reflectivity-vegetation coverage; determining a parameter [Phi] related to the evapotranspiration ratio according to an extended P-T equation and a change of evapotranspiration ratio in the two-dimensional space of the constructed reflectivity-vegetation coverage; and calculating the evapotranspiration of the pre-set time scale based on the determined parameter [Phi]. The evapotranspiration remote sensing inversion method and the application based on the two-dimensional space of the reflectivity-vegetation coverage are of great significance to accurately use the remote sensing to obtain the surface evapotranspiration.

Description

technical field [0001] The invention belongs to the technical field of remote sensing estimation of surface evapotranspiration, and in particular relates to an evapotranspiration remote sensing inversion method and application based on a reflectance-vegetation coverage two-dimensional space. Background technique [0002] Evapotranspiration (Evapotransspiration, ET) is an important part of the surface water cycle and energy balance, which determines the water and heat transfer in the soil-vegetation-atmosphere system. , play an important role. Remote sensing technology is considered to be the most effective method to obtain regional scale evapotranspiration distribution on the earth's surface from the aspects of technology, economy and effectiveness. [0003] At present, the developed remote sensing evapotranspiration estimation methods include one-source model, two-source model and surface temperature-vegetation index triangle / trapezoidal model. The surface temperature-veg...

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Problems solved by technology

However, the traditional triangular / trapezoidal model of land surface temperature-vegetation index has the following limitations: (1) It requires matching data of visible light and thermal infrared, which directly excludes the application of satellite remote sensing sensors that do not have thermal infrared bands but only visible light bands; (2) ) Since the surface temperature is not only affected by soil water content, but also affected by meteorological factors such as solar radiation, air temperature, relative humidity, and wind speed, it is impossible to develop a surface temperature-vegetation index triangle using only satellite single transit data or long-term series data. / The dry and wet sides of the trapezoidal model are determined, and it takes time to calculate and calibrate the parameters every day, which limits the application of this method

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