Flood and Flash Flood

FLOOD AND FLASH FLOOD

Presenters:Leyso, L lycel MayMacaro, RamiahObispado, Djohanna Lene

BAB-3B

SCIENTIFIC DEFINITION

FLOOD FLASH FLOOD

SCIENTIFIC DEFINITION

When water overflows onto dry land.

Flood is…

SCIENTIFIC DEFINITION

A general and temporary condition of partial or complete inundation of normally dry land areas from overflow of inland or tidal waters from the unusual and rapid accumulation or runoff of surface waters from any source.

Flood is…

The covering of normally dry land by water that has escaped or been released from the normal confines of: any lake, or any river, creek or other natural watercourse, whether or not altered or modified; or any reservoir, canal or dam.

SCIENTIFIC DEFINITION

Luzon… Visayas… Mindanao…

FLOOD AND FLASH FLOOD

FLOOD It is an event that occurs

AFTER 6 hours following the end of the causative event which result in fatalities, injuries, and/or significant damage to property.

Flooding events usually take longer to develop and they usually occur along or near larger rivers. The duration of flooding events may extend longer that 24 hours, perhaps several days.

FLASH FLOOD It is an event that occurs

WITHIN 6 hours following the end of the causative event which result in fatalities, injuries, and/or significant damage to property.

Flash flooding events develop rapidly and can occur anywhere water collects, especially areas of steep terrain, and water runoffs. Flash floods rarely last more than 12 hours.

FLOOD AND FLASH FLOOD

FACTS!

The yellow river (Huang He) in China had the four deadliest flood events in world history. The flood of 1931 resulted in 1 to 4 million people being killed.

ELEMENTS/COMPONENTS

Surface Runoff (overland flow)

Subsurface Runoff (inter flow)

Groundwater Flow (base flow)

ELEMENTS/COMPONENTS

• Overland Flow

It is the flow of water that occurs when excess storm water, melt water, or other sources flows over the Earth’s surface. This might occur because soil is saturated to full capacity, because rain arrives more quickly than soil can absorb it.

ELEMENTS/COMPONENTS

• Inter Flow

It is the lateral movement of water in the unsaturated zone that first returns to the surface and enters a stream prior to becoming groundwater. It occurs when water infiltrates into the subsurface, hydraulic conductivity decreases with depth, and lateral flow proceeds down slope.

ELEMENTS/COMPONENTS

• Base Flow

It refers to the surrounding ground water that seeps into the banks of a river or riverbed over time.

ELEMENTS/COMPONENTS

FACTS!

Flood occurs even in the desert.

CAUSES

Heavy Rainfall River Overflow Strong Winds in Coastal Areas Dam Breaking

CAUSES

Heavy RainfallEach time there are more rains than the drainage

system can, there can be floods.

River OverflowIf there is more water upstream than usual, and as it

flows downstream to the adjacent low-lying areas, there is a burst and water gets into the land.

CAUSES

Strong Winds in Coastal AreasSea water can be carried by massive winds and

hurricanes onto dry coastal lands and cause flooding. Water from the sea resulting from a tsunami can flow inland to cause damage.

Dam BreakingToo much water held up in the dam can cause it to

break and overflow the area. Excess water can be also intentionally released from the dam to prevent it from breaking and that can also cause flood.

CAUSES

Other factors:

Volume, spatial distribution, intensity and duration of rainfall over a catchment.

Capacity of the watercourse or stream network to convey runoff.

Catchment and weather conditions prior to a rainfall event.

Ground cover.

Topography.

Tidal Influences.

FACTS!

The Big Thompson Flood in Colorado in 1976, killed 140 people. 95% of those killed in this flash flood tried to outrun the waters along their path rather than climbing rocks or going uphill to higher grounds.

EFFECTS

Economic Environment People and Animals

EFFECTS

Tangible Intangible

Direct

Damage to houses, schools, factories, roads, bridges, furniture, cars, machinery, power plants, water supply.

Loss of life, health effects, loss of ecological value.

IndirectLoss of industrial production, traffic disruption, loss of customers.

Inconveniences of recovery after flood, increased vulnerability of survivors.

EFFECTS

EconomicDuring floods (especially flash floods), roads, bridges, farms, houses and automobiles are destroyed. People become homeless. Additionally, the government deploys firemen, police and other emergency apparatuses to help the affected. All these come at a heavy cost to people and the government. It usually takes years for affected communities to be re-built and business to come back to normalcy. 

EFFECTS

EnvironmentChemicals and other hazardous substances end up in the water and eventually contaminate the water bodies that floods end up in. In 2011, a huge tsunami hit Japan, and sea water flooded a part of the coastline. The flooding caused massive leakage in nuclear plants and has since caused high radiation in that area. Authorities in Japan fear that Fukushima radiation levels are 18 times higher than even thought.

EFFECTS

People and AnimalsMany people and animals have died in flash floods. Many more are injured and others made homeless. Water supply and electricity are disrupted and people struggle and suffer as a result. In addition to this, flooding brings a lot of diseases and infections including military fever, pneumonic plague, dermatopathia and dysentery. Sometimes insects and snakes make their ways to the area and cause a lot of havoc.

EFFECTS

...But... 

There is also something good about floods, especially those that occur in floodplains and farm fields. Floodwaters carry lots of nutrients that are deposited in the plains. Farmers love such soils, as they are perfect for cultivating some kinds of crops.

FACTS!

Just 6 inches of rapidly moving flood water has the strength to knock a person down.

TYPES/KINDS

COASTAL (SURGE FLOOD) FLUVIAL (RIVER FLOOD) PLUVIAL (SURFACE FLOOD)

TYPES/KINDS

COASTAL (SURGE FLOOD)

A coastal flood occurs in areas that lie on the coast of the sea, ocean, or other large body of open water. It is the result of extreme tidal conditions caused by severe rain weather. Storm surge is the leading cause of coastal. In this type of flood, water overwhelms low-lying land and often causes devastating loss of life and property.

TYPES/KINDS

TYPES/KINDS

FLUVIAL (RIVER FLOOD)

Fluvial flood occurs when excessive rainfall over an extended period of time causes a river to exceed its capacity. The damage from a river flood can be widespread as the overflow affects smaller rivers downstream, often causes dams and dikes to break and swamp nearby areas.

TYPES/KINDS

TYPES/KINDS

PLUVIAL (SURFACE FLOOD)

Pluvial flood is caused when heavy rainfall creates a flood independent of an overflowing water body. This happen in any urban area – even higher elevation areas that lie above coastal and river floodplains. It can cause significant property damage.

TYPES/KINDS

FACTS!

In ancient Egypt, people liked the flood along the Nile River because it brought rich soil for farming.

PHILIPPINE SITUATIONER

PHILIPPINE SITUATIONER

The recent flood happened in Philippines is the flood hit in Misamis Oriental last January 17. Heavy rain was a result of the tail-end of a cold front and low pressure area has caused deadly floods have in Eastern Visayas and Northern Mindanao, Philippines. Over 13,000 people have been displaced from their homes. displaced from their homes. Philippines News Agency (PNA) reports that at least 4 people have died in the floods in Cagayan De Oro City, Misamis Oriental,

RECENT HAPPENING

Flooding in Visayas and Mindanao, January 2017

• FloodList reported that, as of 17 January, 4 people had died and over 13,000 people had been displaced from their homes. Cagayan de Oro City, in the province of Misamis Oriental, received at least one month’s worth of rain within 24 hours.

• On 22 January, a second Low Pressure Area (LPA) entered the Philippines. Heavy rain once again resulted in severe flooding to parts of Mindanao, especially the provinces of Agusan del Sur and Compostela Valley.

A third LPA followed on 27 January bringing further heavy rainfall to Mindanao as it interacted with the tail-end of a cold front. The Caraga Region was one of the worst affected areas.

A recent report by the International Federation of Red Cross And Red Crescent Societies (IFRC) says that there were 9 deaths in total. The flooding had damaged more than 1,300 homes and displaced at least 334,000 people. A total of 586 houses in the towns of La Paz and Trento (Agusan del Sur province) were damaged.

MOST PRONE PROVINCES IN THE PHILIPPINES

MOST PRONE PROVINCES IN THE PHILIPPINES

MOST PRONE PROVINCES IN THE PHILIPPINES

MOST PRONE PROVINCES IN THE PHILIPPINES

1. Pampanga2. Nueva Ecija3. Pangasinan4. Tarlac5. Maguindanao6. Bulacan7. Metro Manila8. North Cotabato9. Oriental Mindoro10. Ilocos Norte

IT IS A DISASTER IF WE ARE NOT PREPARED. – Loren Legarda

“Bes, kailangan mo maging preparado sa ano mang pagsubok madadaanan mo. Huwang mong hintayin na magsisi ka sa huli! – Payong kaibigan lang!”

WHAT TO DO

BEFORE DURING AFTER

WHAT TO DO BEFORE, DURING ANG AFTER

BEFORE FLOOD

Assemble disaster supplies.

Be prepared to evacuate.

WHAT TO DO BEFORE, DURING ANG AFTER

BEFORE FLOOD

Review your Family Disaster Plan.

Protect your property.

WHAT TO DO BEFORE, DURING ANG AFTER

DURING FLOOD

Be alert.

Don’t drive unless you have to.

WHAT TO DO BEFORE, DURING ANG AFTER

DURING FLOOD

Get to high ground.

Evacuate immediately if you think you are at risk or are advised to do so.

WHAT TO DO BEFORE, DURING ANG AFTER

DURING FLOOD

Never try to walk or swim through flowing

water.

Shut off the electricity at the circuit breakers.

WHAT TO DO BEFORE, DURING ANG AFTER

AFTER FLOOD

Wait until it is safe to return.

Travel with care.

WHAT TO DO BEFORE, DURING ANG AFTER

AFTER FLOOD

If a building was flooded, check for safety before

entering.

Use extreme caution when entering buildings.

WHAT TO DO BEFORE, DURING ANG AFTER

AFTER FLOOD

Take pictures of the damage.

Get professional help.

WHAT TO DO BEFORE, DURING ANG AFTER

AFTER FLOOD

Your home is no longer a safe place.

When making repairs, protect your property from future flood damage.

SOURCES:

http://www.intermap.com/

http://www.ga.gov.au/

http://kids.britannica.com/

http://www.sulcom.info/

http://daad.wb.tu-harburg.de

http://www.m2comms.com/blog/2016/8/3/10-worst-typhoons-that-went-down-in-philippine-history

www.google.com (for the images)

THANK YOU!