THE FLOODING

THE FLOODING

The flooding problem has become commonplace in the lives of the populations of some cities. But why floods occur? You can fight them?

There are two main causes: natural and anthropogenic

Natural

In general, intermittent streams - those who have never dries during the year - usually have two types of bed: a lower page and through which the water flows during most of the time, and a larger and complement, which is flooded only during periods of flooding. This manifestation is more common in flat areas, also called flood plains. Note the diagram below:

[pic 1]

In the above representation, we have a cross-section of the course of a river are represented in their higher and lower beds. Eventually, depending on the course of water and weather and local conditions, larger bed is flooded, causing flooding in your area. The period at which this occurs varies from river to river and when it's not very common, the riverbed can be occupied by up to a few houses, villages and even cities that are surprised by any natural floods. In some cases, entire towns are under water.

[pic 2]

anthropogenic

Human interference on the waterways, causing flooding and flooding occurs in many different ways.

One problem that seems to have a quick solution is the high level of pollution caused by both the lack of awareness by the population as inefficient systems for garbage collection or delivery of dumpsters around town. With this, the clogging of culverts that would be responsible for contain of the water that raises the level of rivers occurs.

With irregular or disorderly occupation of geographical space - often caused by lack of proper planning - people are subject to the occurrence of floods.

considered the main cause for the floods is undoubtedly soil sealing. With the paving streets and sidewalks and yards of cement, the greater part of the water, which should infiltrate the soil, flows at the surface, leading to an increased elevation of floods and rivers.

A causa considerada principal para as enchentes é, sem dúvida, a impermeabilização do solo. Com a pavimentação das ruas e a cimentação de quintais e calçadas, a maior parte da água, que deveria infiltrar no solo, escorre na superfície, provocando o aumento das enxurradas e a elevação dos rios.

How to fight the floods?

The best way to deal with this problem, in fact, is to perform a proper prevention, through the construction of efficient drainage systems, the evacuation of risk areas, creation of forest reserves in the banks of rivers, decrease pollution levels and generation garbage, and a more consistent urban planning.

ENCHENTES

O problema das enchentes passou a ser algo comum na vida das populações de algumas cidades. Mas por que as enchentes ocorrem? É possível combatê-las? 

Existem dois tipos de causas principais: as naturais e as antrópicas

Natural

Em geral, os rios intermitentes – isto é, aqueles que nunca secam durante o ano – costumam ter dois tipos de leito: um menor e principal, por onde a água corre durante a maior parte do tempo, e um maior e complementar, que é inundado apenas em períodos de cheias. Essa manifestação é mais comum em áreas planas, também chamadas de planícies de inundação. Observe o esquema a seguir:

[pic 3]

Na representação acima, temos um corte transversal do curso de um rio em que estão representados os seus leitos maior e menor. Eventualmente, dependendo do curso d'água e das condições meteorológicas e locais, o leito maior é inundado, provocando as cheias em sua área. O período em que isso ocorre varia de rio para rio e, quando não é muito comum, o leito do rio pode até ser ocupado por algumas casas, vilas e até cidades, que são surpreendidas pelas cheias naturais eventuais. Em alguns casos, cidades inteiras ficam embaixo d´água.