A lot of rain

Typhoon

Hyrricane

Strong wind

Large waves

Huge ocean waves

Snowmelt (snow melting from mountains)

Heavy rainfall (too much for the river)

Dam failure (china dam always fails)

Too much

Short period of time

Quick rise in water level

Rate at which rain falls

High rainfall intensity: a lot of rain

Duration of the rain

Probability of occurrence of a certain amount of rain falling within a certain period of time

How the government plans its development of the land

Floodprone areas: reserved for Lowvalue developments like Parks and fields

Fewer casualties and less economic losses

Example: Minnesota, Minnesota river is surrounded by Parks, residential areas are further away

Elevate or raise properties to a certain height

Minimum Platform Level (MPL): minimum ground level for a development

Development is protected against floods because of the elevated flood

But need to add slope and stairs, increased cost of development

Barriers against floods and protect the developments from floodwater

Levees: raised river banks

Floodwalls: manmade structures to keep out the floodwater

Example: floodprone city of Sacramento builds kilometres of levees along the Sacramento River to protect surrounding land from floods

Increase the capacity of a water body to hold water

Canals and river channels can be widened and deepened to carry more water

Or straightened so water can be drained away quickly

Example: expansion of Bukit Timah canal to increase channel capacity, allowing moderate to highvalue developments LIKE NYGH to be built along the Cana

Cities monitor the water levels in water bodies

Detect when the water level is exceeding the water body, about to overflow

Flood warnings will be issued to public in the event of a flood

Weather forecast: look at weather conditions, predict if a flood might occur

Plan to evacuate a large number of people in the shortest time

Purpose: raise awareness among the people, reduce panic during an actual flood as they are more prepared

Hence reduce the number of casualties as people are aware of how to evacuate

What to do in the event of a flood?

Debris and random "things" washedby the fastmoving floodwaters,cause people to be injured

Waterborne diseases eg cholera

Water is contaminated

Puddles of stagnant water, mosquitoes breed dengue :(

Floods cause buildings to collapse, cause casualties

Sewage pipes burst, sewage spills out and contaminates the water

No clean water, people cannot consume the water

No water supply to run the machines

Floodwaters cause damage toproperty, sweep houses away

Evacuate to shelters

Equipment submerged in water; cause damage to motors and electrical components

Factories cannot operate at full capacity; economic losses

Example: 2011 Thailand floods, industrial Parks flooded, factories cannot operate and people lose their jobs extensive damage to manufacturing industry

During a flood: infrastructure submerged or damaged, becomes impassable

A lot of time and money needed to repair the damaged infrastructure

Example: 2014 heavy rain in Bosnia, destroying roads and bridges, slowing down rescue and relief works

Affect distribution of supply of energy

Flooded road conditions trucks cannot transport gasoline from terminals to gas stations

Power lines damaged power outages

Lack of electricity: factories and anything cannot operate

Emotional distress

Example: adults who have experienced floods more likely to suffer from depression and anxiety

Items washed away by floodwatercan be things the people greatlytreasure

Even the house can hold a special meaning, rebuilding cannot bring back the memories of the house

Cost involved

Floodwater washes the soil away,into the water bodies

Leads to potential water pollution