Global integrated land surface evapotranspiration and estimation system and method based on multiple algorithms

Abstract

The invention belongs to the technical field of meteorological and hydrographic measurement and relates to a global integrated land surface evapotranspiration and estimation system based on multiple algorithms and a method thereof. The global integrated land surface evapotranspiration and estimation method based on multiple algorithms comprises the following steps of: utilizing MODIS (Moderate Resolution Imaging Spectroradiometer) remote sensing data and MERRA reanalyzed meteorological data to drive a MODIS evapotranspiration algorithm module, a rectified PM remote sensing evapotranspiration algorithm module, a Priestly-Taylor evapotranspiration algorithm module, an improved Priestly-Taylor evapotranspiration algorithm module, and a evapotranspiration algorithm module based on experience and methods, in order to respectively obtain their evapotranspiration amounts; according to the sample quality of measured data from a station, extracting surface evapotranspiration observed values from observed data in a global flux station by an observed data extracting module; through a Bayesian model, integrating the extracted surface evapotranspiration observed values with the evapotranspiration amounts calculated by all evapotranspiration algorithm modules to form a Bayesian model integration module. In comparison with the existing technology, in the invention, the method and the system have the advantages of stronger stability and wider application range, thus they have a broad application prospect.

Description

technical field [0001] The invention belongs to the technical field of meteorological and hydrological measurement, and in particular relates to a global land surface evapotranspiration estimation system and method based on multi-algorithm integration. Background technique [0002] At present, the global water resources are increasingly scarce. In order to rationally use and allocate water resources, it is urgent to understand the evaporation water consumption under different vegetation cover and land use conditions. Evapotranspiration includes vegetation interception evaporation, vegetation transpiration, soil evaporation and water surface evaporation. It is the main component of regional water balance and energy balance. An important link in hydrological processes. Land surface evapotranspiration is the main process parameter of water and energy exchange between the hydrosphere, atmosphere and biosphere, and a key variable in the energy cycle, water cycle and carbon cycle...

AI Technical Summary

Problems solved by technology

These model methods use the Monin-Obukhov similarity theory to establish the quantitative relationship between surface meteorological elements, key parameters retrieved by remote sensing (surface temperature, vegetation index, etc.) and land surface evapotranspiration to obtain land surface evapotranspiration. The estimated evapotranspiration varies greatly, even the difference is more than 2 times, and the overall accuracy is not high

Moreover, the single evapotranspiration algorithm has great uncertainty, and a few use the simple multi-algorithm average method. The simple average method has a large uncertainty, which seriously affects the calculation accuracy of land surface evapotranspiration.

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