Method for monitoring regional evapotranspiration on the basis of remote sensing

Abstract

The invention provides a method for monitoring the regional evapotranspiration on the basis of remote sensing, comprising the following steps of: (1) obtaining the multi-temporal and multi-resolution satellite remote-sensing image data at a specific region; (2) carrying out remote sensing inversion to the key parameters on the ground surface; (3) calculating the impedance of each pixel during the exchanging process of the geogas energy by a remote-sensing geogas exchanging model, calculating the sensible heat flux used for heating the air above each pixel, calculating the latent heat energy by an energy remainder formula and inquiring into effective surface impedance; (4) establishing a surface impedance model in a daily dimension so as to obtain a daily ground surface impedance; and (5) working out the daily evapotranspiration by applying a P-M model repeatedly and carrying out time accumulation and dimension down-scaling, thus finally determining the regional ground surface evapotranspiration. According to the validation of the practical measurement at multi-regions, the method for monitoring the regional evapotranspiration is proved to be effective.

Description

technical field [0001] The present invention relates to a method for monitoring regional evapotranspiration based on remote sensing, in particular to a method of using visible light and thermal infrared information provided by remote sensing images, combined with meteorological information near the ground, to calculate the surface energy balance, and through appropriate time expansion, finally A method for determining regional surface evapotranspiration belongs to the technical field of remote sensing applications. Background technique [0002] At present, 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 b...

AI Technical Summary

Problems solved by technology

However, monitoring surface evapotranspiration through remote sensing data is an indirect method of evapotranspiration measurement after all, involving many links and a large amount of data, and there are still some practical technical problems to be solved, such as how to obtain spatially consistent and temporally continuous remote sensing Data, how to make remote sensing data provide calculation methods and calculation parameters required by the model, how to reduce uncertain errors by monitoring the intermediate process and calibrating the model with ground data, etc.

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