Method for determining water utilization efficiency of vegetation layer and ET-GPP-WUE measuring device

Abstract

The invention discloses a vegetation layer water utilization efficiency determination method and an ET-GPP-WUE measurement device, and belongs to the field of agriculture and forestry water resource protection. The method comprises the steps that WUE is the ratio of GPP to ET, the method comprises the steps that the GPP is calculated through a TG model, the ET is calculated through an improved MEP, and input parameters include the earth surface specific humidity, the earth surface temperature, the vegetation leaf area, the earth surface net radiation, the vegetation net radiation, the air specific humidity and the air temperature; wherein input parameters of the improved MEP model, such as earth surface specific humidity, vegetation leaf area, earth surface net radiation, vegetation net radiation, air specific humidity and air temperature, are obtained by real-time on-site acquisition of a measured area, and an input parameter leaf area index of the TG model is obtained by real-time calculation based on the vegetation leaf area acquired on site; the input parameter earth surface temperature of the improved MEP model and the input parameter land surface temperature of the TG model are obtained by real-time on-site acquisition of a measured area by the same temperature sensor. According to the method, the ET and the GPP are coupled through the surface temperature and the leaf area, and inconsistency between the internal independent ET model and the GPP model is avoided.

Description

technical field [0001] The invention belongs to the field of water resources protection in agriculture and forestry, and more specifically relates to a method for determining water use efficiency of vegetation layers and an ET-GPP-WUE measuring device. Background technique [0002] Evapotranspiration (ET) is the second largest water flux in the terrestrial water cycle, accounting for about 60%-70% of precipitation. In the method of calculating ET, the traditional actual evapotranspiration is mainly obtained from ground observation data. Most of the models are built on the basis of water vapor transport and energy balance constraints, and are calculated by ground weather stations. What is obtained is the reference crop evaporation, while The acquisition of actual evapotranspiration is still insufficient. However, the method for determining the gross primary productivity (GPP) of terrestrial ecosystems can only be estimated by relatively low-resolution satellite remote sensin...

AI Technical Summary

Problems solved by technology

The data sources of the TG model and the MEP model are different, which leads to internal inconsistencies in the data during the WUE calculation process, which in turn affects the calculation accuracy of the WUE

Moreover, most of the existing methods are based on remote sensing data, resulting in low-resolution data, difficult to obtain, and questionable reliability if affected by the weather; Prediction, affecting the timeliness of analysis results

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