A quantitative estimation method of monthly evapotranspiration

Abstract

The invention discloses a quantitative estimation method of monthly-scale evapotranspiration, which comprises the following steps: collecting hydrometeorological data in a river basin and adjusting all the data to monthly-scale; contructing the multivariate linear equation of land water storage change data, and performing spatial downscaling and filtering on the GRACE gravity satellite retrieved land water storage change data. The monthly series of actual evapotranspiration in each sub-watershed areobtained, and the trend of seasonal hydrological and climatic change and the characteristics ofspatial and temporal evolution in typical watershed are analyzed. The Budyko water-heat coupling equilibrium equation is optimized, and the quantitative estimation model of monthly actual evapotranspiration is established by using the change of land water reserves. The actual evapotranspiration parameters of monthly scale watershed are estimated quantitatively, and the monthly global evapotranspiration series are calculated according to the calibrated model parameters. The invention enriches the estimation method of river basin evapotranspiration, publishes the monthly value sequence of evapotranspiration with high spatial resolution, and provides scientific basis for scientific research and production work such as flood control and drought resistance.

Description

technical field [0001] The invention belongs to the technical field of hydrology and water resources application, and in particular relates to a method for quantitatively estimating monthly evapotranspiration. Background technique [0002] Global climate change has exacerbated the temporal and spatial variability of hydrological extreme events and hydrological processes, which in turn has caused regional and even global uneven distribution of water resources. In addition, high-intensity human activities also affect the hydrological cycle process by changing the characteristics of the underlying surface of the watershed, leading to increased spatiotemporal variability of water resources and seriously threatening the sustainable development of the social economy. As one of the most critical variables in land surface hydrology, evapotranspiration is closely related to climate change and the evolution of underlying surface cover. Evapotranspiration plays a crucial role not only...

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Problems solved by technology

Current studies on terrestrial water storage and its changes are mostly concentrated in the global or larger watersheds. Due to the limitation of coarse spatial resolution in small watersheds, the results of GRACE inversion are quite different from those of hydrological models.

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