What happened in Belgium in July 2021 ? The dramatic effects of a meteorological cold drop !

July 2021, Western Europe is subjected to heavy rains in different location : an unusual phenomenon cold "the cold droplet" affect East of France, Great-Duchy of Luxembourg East of Belgium and Western Germany. During 2 days, from the 14 of July afternoon to the 16 of July early morning, an area of not less than 100 square kilometers will be showered by nearly 6 times more the normal yearly rain precipitations leading to a massive flooding in East Belgium and Western Germany. Extreme situations will then occur due to this seemingly unpredictable phenomenon : 240 on the 262 counties of the wallon part of Belgium are directly hurt by these massive rains leading to 39 deaths, more than 100000 victims and more than 2,8 bilions euros of damages ! Not less than 8.000 buildings and 45000 private houses are directly hurt, 11000 cars are totally flooded, 559 bridges damaged and 160 sportive halls are under water. On the early morning of 17 of July 15.000 families remain without gas, 66500 others without electricity and 47000 without water. Different dams on the Vesdre and the Ourthe rivers are of concern : will they resist ? The level of the Meuse river is so high that it strongly threatens the strength of the Netherlands dykes 70 kilometers far away. Not far from there in Germany, the soil delaminates itself under the feet of the population ! In EU, the overall damage costs of these 2 days heavy rains are estimated to 48 Billion euros ! This talk intend to review this dramatic event and to emphasize some of the predictable and the unpredictable aspects of natural catastrophes.