GB/T 20484-2017Grade of cold air (English PDF)

Foreword

This standard is drafted in accordance with the rules given in GB/T 1.1-2009.

This standard replaces GB/T 20484-2006 "cold air rating". Compared with GB/T 20484-2006, in addition to editorial changes, The main technical changes are.

- modified the definition of all terms (see Chapter 2, Chapter 2 of the 2006 edition);

- combine "medium strong cold air" and "strong cold air" in five cold air grades into a "strong cold air" level (see Table 1, Chapter 3 of the 2006 edition).

Introduction

Cold air, especially strong cold air and cold wave is one of China's major disaster weather, with a wide range of effects, long duration, disaster Heavy and so on. The frequent occurrence of cold air will not only cause the national economy, especially the huge loss of agriculture and animal husbandry, but also the environment and people's health Live, health and cause serious impact and harm. In order to unify and regulate the impact of China's cold air classification standards, so that cold air monitoring, forecasting, Police, assessment, research and prevention work more standardized, the development of this standard.

1 Scope

This standard specifies the cold air rating and grading method.

This standard applies to cold air monitoring, forecasting, early warning, assessment and scientific research.

2 Terms and definitions

The following terms and definitions apply to this document.

2.3 24 hours of temperature reduction rate

The difference between the daily minimum temperature in the 24 hours after 14.00 and the minimum daily temperature.

3 Level division

The use of cold air affected by a certain period of time in the minimum daily temperature drop and the minimum daily temperature of the two indicators, the cold air Divided into weak cold air, strong cold air, strong cold air and cold four levels. The division method is shown in Table 1.

Weak cold air daily minimum temperature within 48 hours temperature range is less than 6 °C

Stronger cold air Day minimum temperature within 48 hours cooling rate greater than or equal to 6 °C but less than 8 °C; or daily minimum temperature within 48 hours of cooling Amplitude greater than or equal to 8 °C, but failed to make the lowest temperature to 8 °C or below

Strong cold air daily minimum temperature within 48 hours cooling rate greater than or equal to 8 °C, and the lowest temperature to the day to 8 °C or below

Cold wave Day minimum temperature within 24 hours cooling rate greater than or equal to 8 °C, or 48 hours temperature range greater than or equal to 10 °C, or 72 hours down the temperature greater than or equal to 12 °C, and the lowest temperature to the ground to 4 °C or below.

48 hours, The minimum daily temperature for cooling within 72 hours should drop continuously […]