GB/T 36745-2018 in English

1. Background and significance of standard formulation

GB/T 36745-2018 "Typhoon vortex wind measurement data identification specification" is an important standard formulated to meet the needs of meteorological disaster prevention and mitigation and improve the level of typhoon monitoring technology. This standard is managed by the National Meteorological Disaster Prevention and Mitigation Standardization Technical Committee and drafted by the Public Meteorological Service Center of the China Meteorological Administration.

2. Comparison of standard frameworks

3. Technical Details of the Standard

3.1 Zoning Indicators of Typhoon Vortex

Based on the circulation structure characteristics of the typhoon vortex, this standard divides the typhoon wind conditions into three areas:

• Eye area: The central light wind area, with an average wind speed of less than or equal to 10 m/s.
• Eye wall strong wind area: The irregular annular strong wind belt surrounding the eye area, with the maximum wind speed and significantly increased turbulence parameters.
• Outer strong wind area: Characterized by an average wind speed of greater than or equal to 17.2 m/s, including the wind speed change area before and after the typhoon center passes.

3.2 Representativeness of wind data zoning

The representativeness of wind data zoning is determined based on the following indicators:

1. Average wind speed is greater than or equal to 17.2 m/s: Wind direction changes continuously by more than 120 degrees in azimuth.
2. Typhoon process wind speed time curve: Bimodal distribution or unimodal distribution.
3. Bottom average wind speed between the two peaks: Less than or equal to 10 m/s.

4. Implementation suggestions and precautions

4.1 Data collection and processing

In actual applications, the collection and processing of wind data should be carried out in strict accordance with the standard requirements:

• Ensure that the time resolution of wind speed data is not less than once every 3 seconds.
• Use the calculation formula (A.1) of average wind speed and the calculation formula (A.4) of gust coefficient to verify the data.

4.2 Application scenarios and limitations

Although this standard provides a detailed identification method, it is still necessary to pay attention to the following in actual application:

• For typhoon monitoring stations under complex terrain conditions, it may be necessary to make adjustments in combination with the surface roughness and wind profile characteristics.
• It is recommended to combine turbulence intensity and wind profile index for comprehensive identification during data analysis.