Natural disasters related to the excess of the normal level of the river water, occur periodically.In this article, we find out where you can talk about a flood, but when - Flood.We give a definition of each phenomenon and find the causes of their origin.
When and why there is a flood
meaning of the word "flood" as a native Russian, aptly and beautifully interpreted by famous Vladimir Ivanovich Dal with a modern twist is annually recurring seasonal spilling rivers, which is a consequence of the spring melting of ice, snow and rain.This is a fairly long process, causing a significant rise of the river level, it is accompanied by the release of the channel and floodplain inundation.
Research determined that the floods - is the highest in the year, the water content of the river, periodically repeated in the same season.This period usually accounts for a large proportion of annual runoff, sometimes up to 75-80%.Time, opposite the flood, is a low-water period - the period of the lowest level.Throughout the year, the rivers of a certain type, mode, and power, depending on the climatic characteristics of the area derives regular change of periods of high and low water.
Seasonal floods
intensive spring snow and ice melting causes the spring flood, accompanied by rapid and large influx of water.This phenomenon after the winter is typical of many rivers with snow power flowing in the plains.In the life of mountain reservoirs level rise it is more often caused by the summer melting of glaciers and snow in the mountains.
Consider seasonal floods of the rivers flowing on the territory of Russia, determine the nature of their power and the regime.
Rivers, making its way through coniferous, deciduous forests, taiga and forb steppes of the Russian Plain, dominated by snow-fed.Since the most intensive snow melting takes place in March-April, therefore, increase the level comes at the same time. spring flood - a flood that occurs not only in the Russian rivers, but also in Poland, Canada, Alaska and the Scandinavian countries.It began after the establishment of the positive average daily temperatures of air, it slowly at first raises the water level.Then increase the speed increases up to half a day.Soon, the water rises to the medium and small rivers of up to 2-3 meters, large - up to 20 meters.Spill width sometimes reaches 15-30 km.Registered a record rise of the river level corresponds to around 60 meters on the Yangtze River in 1876.
the south of Russia, in the steppes and semi-deserts, we can talk about nutrition rain waters.However, the greatest amount of rainfall in these places as in the spring, and floods occur at the same time.In continental climates of Eastern Siberia are characterized by snow-fed rivers and the spring flood, occurs due to climatic characteristics of the region, a little later - in May.And in the monsoon climate of temperate latitudes of the Far East has always arid winter and humid, rainy summer.Therefore, the rivers in the territories dominated by the power with summer rain water rise.
In other words, high water - is a natural feature of the natural areas in which the rivers flow.
duration flood
on small rivers flood lasts more than 20 days, reaching the highest level for 3-5 day.Its duration on rivers reaches 2-3 months, and the peak rise - 20-30 Day.As a rule, the decline of water lasts 3-5 times longer than its rise.High water on rivers in temperate climates is accompanied by the release of the ice cover.Break-up continues on small ponds up to 5 days, in large - up to 15.
What is a flood?
It is considered to be a very different phenomenon.Since the regularity of natural events can not be foreseen, and the floods resulting therefrom, and which is a short-term rapid rise in water level, irregular and nezakonomeren.In other words, in contrast to the flood, floods can occur at different times of the year.They have nothing to do with the laws of life processes and reservoirs can be caused by rainfall or snowmelt at any time of the year.The monsoon rains that occur, for example, in Southeast Asia, can cause river flooding more than once a year.The duration of flooding is low - from a couple of hours to several days.
Flooding: the effects of flood or flood
Thus, flood - a recurring pattern in the lowland rivers in the spring due to snowmelt and flood is a rapid rise of water in the same waters in the summer after the unexpected heavy rains.
In fact, the rise of water - neither logical nor unexpected - not a flood.The effects that cause floods and flood t. E. The flooding areas, which may occur in connection with the increase in water level in the river, and will be so called.Cause such a phenomenon is the rise of water could be classified differently depending on the laws of chance or expected.
