WAIT!!! Before we head on to the protective measures, we must also be aware that floods can actually be a good thing also. Flooding provides the soil along river banks with fertile alluvium, making soil suitable for farming. Thats why many people still continue living near floodplains so that they can have nice tall plants on the river banks.

Are there people who still grow crops along river bed in Singapore?

1. Clearing of forests - As you all know in the river chapter (directing to the PG), vegetation intercepts surface runoff and allows it to seep into the ground. But what happens when the vegetation are cleared for houses or other recreational uses? There will be no vegetation to hold the soil together and the bare slopes increases surface runoff. More eroded soil and surface runoff flow into rivers and therefore flooding occurs.
2. Urban Development - Almost the same concept as the first cause. Usually, vegetation are cleared for urban development. The concrete floor does not allow rainwater or surface runoff to seep into the ground but instead allow it to flow into rivers. The river channel may not be able to hold the increased volume of water and therefore flooding occurs.
3. Impacts of enhanced greenhouse effect - I don't know bout you all but when i see the word "greenhouse effect", it'll remind me of global warming. So how does global warming causes floods? Well, climate will change, possibility of more rainfall in wetter regions ( lols not religions - had a friend messed up the 2 words). Ice caps or cover in polar regions will melt, resulting in rising sea levels and possibility of floods for low-lying coastal regions.

There you go... The causes of floods. Let's watch some photos eh?

What are floods anyway? Well, floods are actually an overflow of water that usually submerges DRY LAND. It may result from the volume of water within a body of water like a river or lake. There are several causes for floods to occur. Basically there are human and natural causes. We shall explain more about the causes.

Let's start with the natural causes first...

1. Storm surges - At coastal areas, strong winds raise the waves in the ocean to an exceptionally high level. When they crash onto the coast, they may flood the land.
2. Excessive rain - Places with tropical Monsoon climate like India will have heavy rain seasons a.k.a wet seasons. Flooding will occur when the river channel in these countries are not able to contain or hold the excess rainwater.
3. Melting snow - This factor is easy to understand. When the season change from winter to spring, the snow will melt and releases massive amounts of water into rivers.
4. Global atmospheric processes (El Nino and La Nina) - This factor is difficult to understand. The other PG group doing global warming had a hard time understanding what's this is about. El Nino is the abnormal warming of water surface at the southeastern part(SE) of the Pacific Ocean(PO). What happens? Ocean heats up and cause heavy rain over the SE part of PO. Then how bout La Nina? Well, it usually follows after El Nino.La Nina is almost the opposite of El Nino, heating up the SW part of PO. Same thing follows. Ocean heats up and heavy rain occurs over Australia and Indonesia.
5. Movements of the Earth's surfaces - Remember the Indian Ocean tsunami? What am i thinking? of course you remember! Floods are actually caused by earthquakes too. Soil loosens, make river shallower, and then flood occurs. Earthquake trigger off tsunamis which can flood settlements too.