LI-COR New Product ∥ Evapotranspiration ET Measurement - LI-710 Evapotranspiration Measuring Instrument

Evapotranspiration（Evapotranspiration）Also known as evapotranspiration, it includes two parts: surface water evaporation and plant transpiration water consumption. It is an important component of surface water cycling and energy balance. Evapotranspiration plays a key role in the analysis of climate dryness and wetness, water resource utilization and assessment, water management of agricultural crops, and research on ecological environment changes such as desertification.

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Evapotranspiration graphic source/Wikipedia

At present, there are methods to obtain evapotranspiration dataTwo types:Indirect acquisitionLaw anddirectmeasurequantityThe law.

The indirect method for obtaining evapotranspiration requires obtaining two parameters:The crop coefficient and potential/reference evapotranspiration undoubtedly increase the uncertainty of the data.

Vorticity related flux measurement technology can be used for direct measurement of surface evapotranspiration, but due to the complexity of the method and other reasons, it has not been widely applied.

LI-COR Company has newly developed and releasedLI-710 evapotranspiration measuring instrumentThis instrument is based on the widely recognized vorticity related flux measurement technology, which measures the water vapor exchange flux between the surface and the atmosphere, making it a direct method for measuring the evapotranspiration of a sample plotchoice.

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Main features of LI-710 evapotranspiration measuring instrument

Verifiable accuracy

LI-710 uses vorticity related flux measurement technology to measure wind speed and water vapor concentration in the vertical direction at a frequency of 10Hz. Then, mature vorticity related flux data algorithms are used to obtain water vapor flux data and evapotranspiration every 30 minutes.

Compared with the data collected by traditional vorticity related instruments and the potential evapotranspiration data calculated based on the Penman formula, LI-710(Green line in the picture)Show good consistency.

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Directly output the calculated evapotranspiration data

LI-710 has an embedded calculation module that directly outputs the calculated evapotranspiration data.From instrument installation to data output, usability has been fully demonstrated.

Convenient and efficient installation

Minimalist design, ready to use

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SDI12 data output

A cable that facilitates data collection and integration into existing measurement systems.

1.5W low power consumption

Convenient for deployment in the field.

No calibration required, extremely low maintenance

Convenient for multi-point deployment, without the need for professional data analysis experience related to vorticity.

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Should we choose LI-710 or a traditional vorticity related system?

LI-710 can directly output evapotranspiration data without requiring users to have professional experience in analyzing vorticity related data. But if CO is still needed2For flux data, a more comprehensive vorticity related measurement system is needed. Please refer to the table below to help you make a choice.

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Application Cases

Land IQ scientists use LI-710 to analyze agricultural water demand in California region

Land IQ is a company that provides agricultural science consulting and remote sensing services, headquartered in CaliforniaofSak sliding doorTuo.The Land IQ ET developed by it is a data-driven field water usage model that utilizes ground data from over 80 meteorological stations.

Their clients are mainly local water resources management departments, including nearly 40 groundwater sustainable development agencies (GSAs).These institutions monitor the evapotranspiration of 35-40 different crops, covering a total area of over 3 million acres, mainly involving six agricultural counties: Stanislaus, Madera, Fresno, Tulare, Kings, and Kern.

Frank Anderson, a scientist at Land IQ, collects and analyzes data from meteorological stations every month, and uses this information as the data basis for the evapotranspiration ET model.He said:We strive to collect comprehensive and accurate evapotranspiration data for our customers.

Since November 2022, Land IQ has deployed 5 sets of LI-710 evapotranspiration measurement instruments in its research network, which are installed next to existing weather stations.

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Anderson said:We want to deploy LI-710 on a range of different coverage types, including fallow land, pistachio forests, apricot forests, citrus forests, and alfalfa fields.Alfalfa planting is quite special because it requires periodic cuttings, which can be used to analyze and compare changes in evapotranspiration data.”These crops have different coverage rates, with approximately 25% in the Happy Fruit Forest and nearly 90% in the Apricot Tree Forest.

They installed LI-710 during periods of low evapotranspiration ET throughout the year.Anderson is very satisfied with the data collected by LI-710, saying:The data collected by LI-710 with very low evapotranspiration has high reliability.”

On the alfalfa plot next to a dairy farm, the LI-710 they installed works in a high dust environment.Anderson said, 'This is a challenge because there are ammonia, volatile organic compounds, and dust particles in the sample air.'.”LI-COR has developed a tool to assist users in easily replacing filters.

Anderson believes that the installation and maintenance of LI-710 are very simple.Two people spent less than an hour installing LI-710 into the existing weather station system.

Anderson is very satisfied with the data collected by LI-710.He said:Our entire mathematical model needs to be based on reliable evapotranspiration measurement data, and we hope to deploy more LI-710 in the network.”