What Is a Loss History?

The average long-term water-logging disaster (average long-term water-logging disaster) is the annual average of the waterlogging losses in a historical period. That is, the sum of the actual flooding losses in each year in a certain period of time divided by the annual average of the total number of years in that period or the annual expected value of flooding losses that may occur in a certain period in the future. Generally, the growth rate of flood losses in the past years should be considered. ^[1]