Potential evapotranspiration estimation method considering underlying surface condition change

Abstract

The invention discloses a potential evapotranspiration estimation method considering underlying surface condition change. The method comprises the following steps: collecting pixel scale data of a research site or region; calculating the maximum blade stomatal conductance through the atmospheric CO2 concentration; combining the maximum leaf stomatal conductance with the leaf area index to calculate vegetation canopy conductance; calculating aerodynamic conductivity according to the near-surface wind speed and the canopy height; calculating vegetation available energy and bare soil available energy according to the available energy; and adding the vegetation potential transpiration amount and the bare soil potential transpiration amount to calculate the surface evapotranspiration amount. The method gets rid of hypothesis constraints of underlying surface conditions and vegetation canopy stomatal conductance invariance, and overcomes the applicability problem that an existing potential evapotranspiration algorithm is only suitable for limited surface coverage vegetation types; thus, a mathematical relation between the leaf maximum pore conductance and the atmospheric CO2 concentration under different ground cover vegetation types are established, and the process that the dynamic change of the atmospheric CO2 concentration affects the canopy pore conductance and potential evapotranspiration can be described reasonably.

Description

Technical field[0001]The present invention relates to a potential evapoatization estimation method, and more particularly to a potential evapoatization estimation method for considering the change of the lower surface condition. It belongs to the field of satellite remote sensing applications.Background technique[0002]Potential evaporate is referring to an ecosystem or a regional evaporation capability of the region under full water supply conditions. At the scope of meteorology and hydroxation, potentially evaporate is an important research content of surface water balance and energy balance. In practical applications, potentially evaporated estimates have been widely used in farmland irrigation management, crop demand water, drought monitoring, water resources effective development and utilization, etc. For global climate change, water resources evaluation, forest resource management It is of great significance to ecological security. Early potentially evaporated algorithms mainly...

AI Technical Summary

Problems solved by technology

Therefore, the currently most widely used FAO Penman-Monteith algorithm can neither meet the applicability requirements of different vegetation cover types (such as forest ecosystems with large climate spans, high canopy heights, and complex structures), nor can it meet the conditions of the underlying surface. Significant changes (such as the increase of vegetation leaf area index LAI, atmospheric CO 2 Concentration rise, etc.) affect the validity requirements of vegetation transpiration and potential evapotranspiration estimation accuracy

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