Flood disaster always is one of the severe natural disasters
in Northeast China, and it is juxtaposed with the drought disaster
as two main natural disasters. Flood disaster is caused by the excessive
amount of water and the movement or the form of existence which can do harm to
human's society under some environmental conditions. The flood disasters include
rainstorms, snow-melting flooding, mudslides, storm surges, soil salinization,
and snow disasters, etc., among which the rainstorm disaster is the most frequent
and most serious loss. In the historical document, people used "rain", "heavy rain"
and "lao" to describe flood disasters. By 20th century, meteorological
and hydrological observation had developed, and people started to use "rain condition",
"water condition" and "disaster condition" these 3 quantitative indicators
to describe flood disaster. The flood disaster records in Northeast China
can be divided into two sections, the two periods: before and after
the founding of the People's Republic of China. Generally speaking,
the data record in the previous period is simple, the temporal and spatial
distribution characteristics of the disaster are not prominent,
the disaster situation is not complete, and all types of flood disasters
are simply called floods. The rainfall, flood and disaster datas in the latter
period are relatively sufficient, and it has the basis for compiling flood classification.
The information is provided by Disaster Risk Reduction Knowledge Service.