Construction method of regional scale evapotranspiration model synchronously considering dynamic changes of vegetation canopies and root systems

Abstract

The invention provides a construction method of a regional scale evapotranspiration model synchronously considering dynamic changes of a vegetation canopy and a root system. The construction method comprises the following steps: S1, calculating net radiation, net radiation components and influence factors through regional scale data required by a PT-JPL model; s2, estimating the plant effective root depth Zr of the Chinese regional scale based on a Guswa model; and S3, coupling the effective root depth Zr of the plant into the PT-JPL three-source evapotranspiration model to construct a regional scale evapotranspiration model synchronously considering the dynamic change of the vegetation canopy and the root depth. According to the model, the vegetation dynamic change and the plant effective root depth are jointly incorporated into evapotranspiration calculation and analysis, the transverse change (vegetation coverage) of the vegetation dynamic state is considered, meanwhile, the longitudinal change (root depth) of the vegetation change is considered, the multi-scale analysis function is achieved, the requirements for ground data and aerodynamics are low, and the method is easy to implement. And the improvement of the evapotranspiration of the regional scale and the evapotranspiration component estimation accuracy is promoted.

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 evapotranspiration model that simultaneously considers the dynamic changes of vegetation canopy and root system. 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. Evapotranspiration ET not only depends on energy and water volume, but also depends on vegetation physiological processes during vegetation changes. Many factors are closely related, which makes it difficult to accurately estimate regional-scale evapotranspiration. In addition, the response of regional-scale evapotranspiration to vegetation changes is also quite different, and the physiological differences of different species are huge. The estimation of evapotranspiration should...

AI Technical Summary

Problems solved by technology

[0006] In areas with drastic changes in vegetation, the current model has a problem with the inaccuracy of quantifying ET and its subdivision

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