Construction method of regional scale double-source evapotranspiration model considering dynamic vegetation change

Abstract

The invention provides a construction method of a regional scale double-source evapotranspiration model considering dynamic vegetation change. The construction method comprises the following steps: S1, performing regional evapotranspiration estimation of the double-source evapotranspiration model: calculating net radiation data of a required regional scale input by a model; calculating net radiation components Rns and Rnc; calculating each influence factor; performing simulated estimation on evapotranspiration ET; s2, carrying out parameter optimization under different vegetation types; s3, performing simulation effect verification of the regional scale double-source evapotranspiration model considering dynamic vegetation change: performing site scale verification; performing regional scale verification; and performing basin scale verification. According to the model disclosed by the invention, the dynamic change of the vegetation is incorporated into evapotranspiration calculation andanalysis, and meanwhile, the model is expanded to a regional scale, has a multi-scale analysis function and has the advantage of few aerodynamic parameters of the PT-JPL original model, has low requirements on ground data and aerodynamics, and plays a role in promoting the accuracy improvement of regional scale evapotranspiration estimation.

Description

technical field [0001] The invention relates to the technical field of ecological environment monitoring, in particular to a method for constructing a regional-scale dual-source evapotranspiration model considering dynamic changes in vegetation. Background technique [0002] Due to the lack of air resistance data (such as wind speed, surface impedance, and vegetation height) when estimating regional scale ET, the physical mechanism is complex and covers many factors. Evaporation depends not only on energy and water, but also on vegetation physiological processes during vegetation changes These factors are closely related, which makes it difficult to accurately estimate regional-scale evapotranspiration. In addition, the response of evapotranspiration to vegetation changes at the regional scale is also quite different, and the physiological differences of different species are huge. Vegetation types should be introduced into the estimation of evapotranspiration. [0003] Rem...

AI Technical Summary

Problems solved by technology

Especially in areas with drastic vegetation changes, the impact of vegetation dynamic changes on ET cannot be underestimated. Therefore, in the calculation process of evapotranspiration, it is necessary to consider the impact of vegetation dynamic changes on ET, so as to achieve accurate calculation and simulation of ET. However, most of the existing evapotranspiration estimation models do not introduce systematic vegetation physiological factors, resulting in the influence of vegetation dynamic changes on evapotranspiration cannot be clearly defined

Evapotranspiration estimates widely used by the academic community, such as the PT-JPL model, do not take into account the impact of vegetation dynamic changes

In the correction of the three sensitive parameters, a complete parameterization scheme has not been obtained for specific vegetation types

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