Flood is a natural process of natural phenomena

Natural cataclysms associated with excess of the usual level of river water occur periodically. In this article we will find out when it is possible to talk about high water, and when - about high water. Let's define each phenomenon and find out the reasons for their origin.

When and why there is a flood

The meaning of the word "high water" as a native Russian, well-known and beautifully interpreted by the famous Vladimir Ivanovich Dahl in modern interpretation means the annual recurring seasonal flooding of rivers, which is the result of spring melting of ice, snow, rains. This is a fairly long process, causing a significant rise in the level of the river, accompanied by its exit from the river bed and the flooding of the floodplain.

It is scientifically determined that the high water is the highest in the year water content of the river, which periodically recurs in the same seasons. For this period, usually a large proportion of the annual runoff, sometimes up to 75-80%. The time, the opposite of the flood, is the low - level period. Throughout the year, rivers of a certain type, regime and food, depending on the climatic features of the area, regularly change the periods of high and low water.

Seasonal Flood

Intensive spring melting of snows and ice causes a spring high water, accompanied by a rapid and large influx of water. This phenomenon after winter is typical for many rivers with snow feeding, flowing on the plains. In the life of mountain reservoirs, the rise in the level is more often caused by the summer thawing of glaciers and snow in the mountains.

Let us consider the seasonal nature of river flooding occurring on the territory of Russia, determine the nature of their diet and regime.

By rivers that make their way through coniferous, deciduous forests, taiga and mixed herbs along the Russian plain, snow food prevails. Since the most intensive melting of snow takes place in March-April, therefore, the rise in level occurs at the same time. Spring high water is the rise of water, which is observed not only on Russian rivers, but also in Poland, Canada, Alaska and Scandinavian countries. Beginning with the establishment of positive mean daily air temperatures, it first slowly raises the water level. Then the rate of increase increases to half a meter per day. Soon the water rises on medium and small rivers up to 2-3 meters, on large - up to 20 meters. Spread width sometimes reaches 15-30 km. The recorded record of the rise in the river level corresponds to a mark of 60 m on the Yangtze River in 1876.

In the south of Russia, in the steppes and semi-deserts, one can speak of rainwater feeding of reservoirs. However, the greatest amount of precipitation in these places also falls on the spring, and the flood comes at the same time. In the continental climatic zones of Eastern Siberia, the rivers are characterized by snow feeding and spring flood, which, due to the climatic features of the region, comes somewhat later - in May. And in the monsoon climate of the temperate latitudes of the Far East, always dry winter and wet, rainy summer. Therefore, rivers on these territories are dominated by rainwater with a summer rise in water.

In other words, high water is a natural feature of those natural zones in which rivers flow.

Duration of floods

On small rivers the high water does not last more than 20 days, reaching the highest level on the 3-5th day. Its duration on large rivers reaches 2-3 months, and the peak of recovery is on the 20th-30th day. As a rule, the decline of water lasts 3-5 times longer than its increase. Floods on rivers in temperate climates are accompanied by clearing of the ice cover. Ice drift continues on small reservoirs up to 5 days, on large ones - up to 15 days.

What is flood?

It is considered to be a completely different phenomenon. Since the regularity of spontaneous events can not be foreseen, then the flood, which is their consequence and representing a short-term rapid rise in the water level, is irregular and irregular. In other words, in contrast to the flood, floods can occur at different times of the year. They are in no way connected with the regular life processes of water bodies and can be caused by rain or snowmelt at any time of the year. Monsoon showers, arising, for example, in South-East Asia, can cause flooding of rivers more than once a year. The duration of the flood is not great - from a couple of hours to several days.

Flooding: consequences of flood or high water

Thus, high water is an annual regularity on flat rivers in the spring, caused by the melting of snow, and a flood is the rapid rise of water in the same reservoirs during the summer period after unexpected heavy rains.

In fact, the rise of water - whether natural or unforeseen - is not a flood. The consequences caused by high water and flooding, i.e. flooding of the terrain, which can occur due to the rise in the water level in the river, will be so called. The rise of water caused by such a phenomenon can be classified in different ways depending on the degree of regularity, expectancy or chance.