Oversvømmelser forekommer, når vand oversvømmer mindre eller større landområder, altså når store mængder vand samler sig et sted. De er ofte uventede, og natur skabte. Det kan eksempelvis ske, som følge af kraftig regn (skybrud), smeltning af is/sne eller storme (stormflod). Den mest almindelige form for oversvømmelser er, når en flod går over sine breder eller når der er så kraftig nedbør, at områdets sanitetssystem ikke kan følge med, altså ved skybrud eller større byger. Der er selvfølgelig også nogle få positive egenskaber ved en oversvømmelser, men i det følgende, vil der være fokus på de negative, da det er de dominerende faktorer.

Skybrud – svære at håndtere

I Danmark definerer vi skybrud, som en nedbørintensitet på 15 millimeter eller derover, på 30 minutter eller derunder. Vi havde f. eks sidst kraftig nedbør i Danmark i sommers, mens det var så voldsomt i Københavnsområdet, at det blev varslet som skybrud. Skybrud kommer fra byger, og byger er svære at have kontrol over. Byger er per definition lokale, og det er næsten umuligt at forudsige deres geografiske område. Dette har selvfølgelig en indflydelse på varslingen.

"Byger er en slags vejrets 'trold i æske'. De kan dukke op ud af det blå, levere en måneds nedbør på en time og så forsvinde lige så hurtigt, som de kom", forklarer meteorolog Knud-Jacob Simonsen, der til daglig leder DMI's Sektion for Land og Farvand og dermed har ansvaret for de vagthold, som udarbejder vejrudsigterne for Danmark[1].

Fremtiden – hvad er løsningen?

Oversvømmelser kan altså medføre store skader, enten ved, at store mængder vand strømmer igennem landet og river alting med sig, eller ved at vandet bliver liggende og forårsager vandskader på de omkringliggende bygninger.

Sidste år, gik billeder af oversvømmelserne i Bangkok og Centraleuropa verden rundt. Her stod redningsarbejdere og frivillige på stribe og stablede sandsække. Det billede kan meget vel ændre sig over de næste få år.

Antallet af oversvømmelser er steget de seneste 30 år. Det skyldes blandt andet, at flere og større områder er blevet urbaniseret, hvorfor vand ganske simpelt har vanskeligere ved at komme væk. Desuden får den globale opvarmning skyld for stadig flere skybrud, en stigning i vandstanden i floder og have, flere storme og orkaner og generelt flere ekstreme vejrhændelser.

Det er forskellige måder man kan bekæmpe oversvømmelser på.

Sandsække kræver utallige mandstimer og stor kapital. Denne metode er brugt, med større eller mindre held,
lige siden man agede med heste.

Anvendelse af sandsække kræver meget tid, arbejdskraft, lagerplads, materialer, og  transport . Det er besværligt at håndtere, også efter brug.

Det tyder på, at oversvømmelser vil forekomme mere hyppigt i fremtiden, derfor har der været behov for en bedre og billigere løsning end sandsække.

At bekæmpe vand med vand er en spændende ny tilgang til oversvømmelser, og er uden tvivl fremtiden. Kort fortalt, går det ud på, at man anlægger nogle store rør, som man fylder med luft og herefter opfylder med vand. Det er en billigere, nemmere og mindre krævende løsning til bekæmpelse af oversvømmelser og bliver derfor en mere og mere interessant model.

As soon as nature releases her fury, it really is guaranteed to cause disastrous results. Simply take a quick look at what tsunamis, severe storms, wildfire, and floods has caused humankind. Life is taken away, homes wrecked, future modified, and to some, there is no other way but to start yet againfrom scratch.



Each one of these perhaps have never occurred if, to begin with, everyone has been gentler plus more attuned to the requirements and call for help of the environment. Sadly, that's not the situation.



People seem to be stretching the tolerance of Nature. However, if our family’s lives are essential to us, then it's about time to at last care for the ecosystem. So that as a deterrent on the adverse results of surges, it is advisable to work with nature and come up with natural flood protection solutions.



A long time ago, flood protection initiatives would mean paving streams using cement or sandbags. They have, at some point, proven to be very efficient in controlling floods. Yet in the drawback, they could be an eye sore.



On the other hand, natural flood protection methods are more appealing, maintain natural settings, help the grade of the water and then have much lesser impact on the ecosystem.



One particular natural approach is by applying crib walls. Inactive timber are lined up and buried close to the banks. After a number of years, the buried wood logs will decay and will act as the spine in which foliage is going to bloom. The roots of this plants can then give the defense against land loss.



The other way is by building overflow channels. With this, you are increasing the water source’s capacity to get more flood waters. The overflow channel will be opened should there be a threat associated with a massive overflow. Thus, the initial water bed along with the natural habitat of wildlife are preserved.



In certain places where enormous flood can't be ceased, various bypass channels are designed into place as a possible added flood protection. All these bypass channels are built below the ground. When the water keeps rising, any additional water will flow on culverts that happens to be then diverted to other destinations by way of these channels, therefore, controlling the overflow within the initial area.



If worse reaches worst, concrete channels will be the sole method to forestall considerable flooding mainly because of the proximity of homes on the streams. This nearness is exactly what prevents the renovation of the ponds and also the creation of natural beds.

When a natural calamity attacks a country or even a state, it results in a depressing and saddening aura felt by the disturbed people. Ruined properties and sacrificed lives, these are simply a number of the negative outcomes each time a natural disaster transpires. Of course, no one wants to generally be affected or be in the place wherein a disaster will definitely take place. But in the event that there's hardly any other way, basic safety processes and methods will probably be your key point in living through.

One of the several natural disasters that any country or state could encounter is inundating. Flood takes place when there's a surplus quantity of water moving in a body of water (e.g. river, stream) and the excess water locates another way to pass through and sometimes it means it would flow in encompassing dry land. Every time a flood happens, it is rather quite likely that properties can be damaged and lives will be lost.

These are just examples of the impacts that the flood can do to a country or even simply a state. Though an efficient flood control may be done, the after-effects and impacts it discharges cannot be bearable. First of all, a flood damages the properties where water makes a course. It may possibly bring a home down and knock around a big heap of land. It may well also endanger the lives of untold millions of persons and wildlife residing in the region.

It may also bring problems to the hydroelectric power of a certain country so financial losses can be very substantial whenever a flood happens in one area. Although with negative impacts comes along with great results and this includes land soil is usually more fertile. Far more nourishing substances are brought in whenever a flood occurs and as a consequence causing plant life to grow better than before.

When a flood disaster appears to be out of control, it is just but natural to search for flood control ways. A number of the means we put together in here consists of making sandbags. Sandbags are recognized to be the most efficient of all flood control methods. It's actually a great deal of work actually but it’s cheap and sturdy. Dams however, are exactly what a big metropolis would assemble for the security of the people.

The best thing about dams is it may be managed to what number of water may be released and taken back in. In Europe and America, it is often a consistent predicament that there are no coast protection to avoid thunderstorm surge from flooding the whole area. So seawalls and barrier islands are constructed to be a flood control technique.