COMBATING HAIL WORLDWIDE

The damage caused by hailstorms worldwide is very significant. This results in annual losses of around 5 to 6 billion US dollars (USD).

For this reason, many countries have studied the phenomenon of hail production and ways to combat it. At the beginning of this century, hail projects were being implemented in more than 48 countries, protecting more than 88 million hectares of agricultural crops.

Worldwide, several categories of means and/or methods of protection are used to combat hail, such as: means of active intervention in the atmosphere which use certain substances to seed convective clouds:

• rocket method – applied in Russia (2.5 million ha), Bulgaria, Italy, Moldova, Uzbekistan, Serbia, Ukraine, Argentina, Macedonia, Tajikistan, Romania, China (over 40 million ha);
• aviation method – used in the USA, Canada, Austria, Germany, Greece, Argentina; since 2019, local experiments have also started in Romania;
• the method of land-based generators – applied in France, Italy, Hungary, Brazil, Germany, Spain, the Netherlands;
• Artillery method – applied through 18 projects in China, Mongolia;

Passive means of protection against hail fall that do not use active interventions in the atmosphere:

• hail nets method, placed over the area to be protected, on relatively small areas;
• sonic generators (cannons), which are used in many Central and Western European countries; their effectiveness is not recognised by the WMO (World Meteorological Organisation), as it has not been scientifically proven;
• combined method: involves the simultaneous use of two or more of the methods outlined above.

These methods have been studied in depth in certain countries which, over the years, have introduced and perfected certain technologies, thus becoming real schools in the field:

• Russian school – for the missile method;
• American school – for the aviation method;
• French school – for the method of terrestrial generators.

Effectiveness in combating hail differs from one method to another. Based on the calculations made, it appears that the rocket method ensures an effectiveness of at least 75% and can reach up to 92%.