Lesson 4.pdf

Hydrometeorological and Coastal Processes and Hazards Lesson 4  Hydrometeorological and Coastal hazards is caused by climate processes which include tropical cyclone (typhoon), floods, tsunami, storm surge, and coastal erosion. I. Tropical Cyclones Tropical cyclones or typhoons...

Hydrometeorological and Coastal Processes and Hazards Lesson 4  Hydrometeorological and Coastal hazards is caused by climate processes which include tropical cyclone (typhoon), floods, tsunami, storm surge, and coastal erosion. I. Tropical Cyclones Tropical cyclones or typhoons are violent storms that begin in the tropics. They are the most powerful of all weather systems. In the Western North Pacific around the Philippines, Japan, and China the storms are known as typhoons, while in the North Atlantic Ocean and the Eastern North Pacific they are referred to as hurricanes. In the Indian Ocean, cyclone. I. Tropical Cyclones The Philippine Atmospheric Geophysical and Astronomical Services Administration (PAGASA) tropical cyclone classifications are: a. Tropical Depression b. Tropical Storm c. Severe Tropical Storm d. Typhoon or Hurricane e. Super Typhoon ▪ Monsoons A monsoon is a seasonal wind and rain pattern, and the word “monsoon” is believed to have originated from the Arabic word mawsim (season), via Portuguese and the Dutch monsun. There are two known monsoons in the Philippines that occur every year: Summer Southwest (Habagat) and Winter Northeast Monsoon (Amihan). ▪ Monsoons - Amihan: brings cloudless skies and nippy mornings during the dry season (October to late March) - Habagat: brings heavy rains and some deadly typhoons (June to September) ❑ Tropical Depression. Highest sustained winds up to 61 km/hour; ❑ Tropical Storm. Highest sustained winds of 62 to 88 km/hour; ❑ Severe Tropical Storm. Highest sustained winds of 89 to 117 km/hours; ❑Typhoon or Hurricane. Highest sustained winds of 118 to 220 km/hour. ❑Super Typhoon. Highest sustained winds exceeding 220 km/hour. I. Tropical Cyclones Tropical cyclones are formed over the warm tropical water in ocean and die down when they move overland. Meteorologists try to forecast where and when the center of the storm, the eye, will reach land in order to warn people about the damage caused by the strong winds, heavy rain, and storm surge associated with the storm. ▪ A Tropical Cyclone Wind Signal (TCWS) is a plain text warning to particular land area that may experience winds of at least strong breeze in strength on the Beaufort Scale within at most 36 hours from the time the signal is put into effect during the passage of a tropical cyclone. POTENTIAL IMPACTS: ▪ House of poor construction (e.g., wood frame, bamboo, makeshift), old dilapidated structures, and other structures made of light materials will suffer minimal to minor damage. ▪ Some banana and similar plants are tilted, while twigs of small trees may sway with the wind. ▪ Rice crops, especially those in flowering and ripening stages, may suffer some damage. ▪ Minimal disruption to public transportation. POTENTIAL IMPACTS: ▪ Minor to moderate damage may occur to makeshift or old dilapidated structures, and other structures made of light materials. Houses of poor and average construction (e.g., unreinforced CHB/masonry, mixed timber-CHB) may receive minor roof damage. ▪ Unsecure, exposed lightweight items may become projectiles which may cause additional damage. ▪ Some electrical wires may be blown down, resulting in local power outages. ▪ Minor to moderate disruption to public transportation. ▪ Most banana and similar plants are tilted, with some stooped or downed. Some small trees blow over, with twigs and branches of frail trees broken. Considerable damage is likely to rice and other similar crops, especially those in flowering and ripening stages. ▪ Makeshift or old, dilapidated structures, and other structures made of light materials may suffer substantial damage. Houses of poor or average construction will have considerate roof damage, some blown-out windows, and/or partial wall damage. Well-constructed houses (e.g., reinforced/pre-cast CHB, reinforced concrete moment frame) may suffer minimal to minor roof damage. ▪ Warehouses and other buildings in industrial parks may suffer minor to moderate damage. ▪ Unsecured, exposed outdoor items of light to moderate weight may become projectiles, causing additional damage or injuries. ▪ Many areas may suffer power outages with numerous downed power lines and posts. Minimal to minor disruption in telecommunications and potable water supply. ▪ Moderate to significant disruption to public transportation ▪ Some small trees. most banana and similar plants, and a few large trees are downed or broken. Rice and other similar crops, especially those in flowering and ripening stages may suffer heavy damage. ▪ Severe damage will occur to makeshift or old, dilapidated of light structures, and other structures made of light materials. Houses of poor or average construction may receive major damage, including complete roof failure and possible wall collapse; a few may suffer severe damage. ▪ Most well-constructed houses may suffer minor to moderate roof damage, with some houses experiencing major roof failure; blown out windows are also likely. ▪ Failure of aluminum and steel roofs and coverings may occur in buildings at industrial parks. ▪ Some glass in most high-rise office buildings may be blown out; a few of these buildings may have minor to moderate damage and higher proportion of blown-out windows due to swaying. ▪ Considerable airborne debris will be generated and may cause damage, injury, and possible fatalities. ▪ Near total loss of power supply and telecommunications due to numerous downed power lines, poles, and cellular towers. Diminished availability of potable water supply is also likely. ▪ Significant to severe disruption to public transportation. ▪ Significant damage to banana and similar plants. Most small tress and some large trees will be broken, defoliated, or uprooted. Almost total damage to rice and other crops. ▪ Severe to catastrophic damage is expected to houses of poor or average construction, makeshift or old, dilapidated structures, and other structures made of light materials. Well- constructed houses may suffer substantial roof and wall failure or damage. ▪ Many industrial buildings will be destroyed, with only few receiving partial roof and wall damage. ▪ Most windows will be blown out in high-rise office buildings; Moderate structural damage is possible due to swaying. ▪ Extensive damage will be cause by airborne debris. People, pets, and livestock exposed to the wind are at great risk of injury or death. ▪ Electricity, potable water supply, and telecommunications will be unavailable for prolonged periods due to significant disruption in infrastructure. ▪ Prolonged significant to severe disruption to public transportation. ▪ Vast majority of the trees will be broken, defoliated, or unrooted. Banana and similar plants will be extensively damaged. Few trees, plants, and crops will survive. PAGAASA Rainfall Warning System  Top five destructive typhoons to ever hit the country: ▪ Typhoon Haiphong (1881) ▪ Typhoon Haiyan (Yolanda) (2013) ▪ Tropical storm Thelma (Uring) (1991) ▪ Typhoon Bopha (Pablo) (2012) ▪ Typhoon Angela (1867). Before A Typhoon Hits 1.To begin preparing, you should build an emergency kit and make a family communications plan. 2.Know your surroundings. 3.Learn the elevation level of your property and whether the land is flood-prone. This will help you know how your property will be affected when storm surge or tidal flooding are forecast. 4. Identify levees and dams in your area and determine whether they pose a hazard to you. 5. Learn community Typhoon evacuation routes and how to find higher ground. Determine where you would go and how you would get there if you needed to evacuate. 6. Make plans to secure your property. 7. Cover all your home’s windows. Permanent storm shutters offer the best protection for windows. A second option is to board up windows with 5/8” marine plywood, cut to fit and ready to install. Tape does not prevent windows from breaking. 8. Install straps or additional clips to securely fasten your rood to the frame structure. This will reduce roof damage. 9. Be sure trees and shrubs around your home are well trimmed so they are more wind resistant. 10. Clear loose and clogged rain gutters and downspouts. 11. Reinforce your garage doors; if wind enters a garage it can cause dangerous and expensive structural damage. 12. Plan to bring in all outdoor furniture, decorations, garbage cans, and anything else that is not tied down. 13.In a strong typhoon, a loose object is a missile! 14.Determine how and where to secure your boat. 15.If in ahigh-rise building, be prepared to take shelter on or below 10 floor. th During A Typhoon If a typhoon is likely in your area, you should: 1. Listen to the radio or TV information. 2. Secure your home, close storm shutters and secure outdoor objects or bring them indoors. 3. Turn off utilities if instructed to do so. Otherwise, turn the refrigerator thermostat to its coldest setting and keep its doors closed. 4. Turn off LPG tanks. 5. Avoid using the phone, except for serious emergencies. 6. Moor your boat if times permit. 7. Ensure supply of water for sanitary purpose such as cleaning and flushing toilets. Fill the bathtub and other larger containers with water. 8. Find out how to keep food safe during and after an emergency. You should evacuate under the following conditions: 1. If you are directed by local authorities to do so. Be sure to follow their instructions. 2. If you live in a week home or temporary structure – such shelter are particularly hazardous during typhoon no matter how well fastened to the ground. 3. If you live in a high-rise building – typhoon winds are stronger at higher elevations. 4. If you live on the coast, on a floodplain, near a river, or on an island waterway. If you are unable to evacuate, go to your wind-safe room. If you do not have one, follow these guidelines: 1. Stay indoors during the typhoon and away from windows and glass doors. 2. Close all interior doors – secure and brace external doors. 3. Keep curtains and blinds closed. Do not be fooled if there is a lull; it could be the eye of the storm – winds will pick up again. 4. Take refuge in a small interior room, closet or hallway on the lowest level. 5. Lie on the floor under the table or another sturdy object. 6. Avoid elevators. After A Typhoon 1. Continue listening to radio pr the local news for the latest updates. 2. Stay alert for extended rainfall and subsequent flooding even after the typhoon or tropical storm has ended. 3. If you have become separated from your family, use your family communications plan or check the Emergency Numbers Plan. 4. If you evacuated, return home only when officials sat it is safe. 5. Drive only if necessary and avoid flooded roads and washed-out bridges. 6. Stay off the streets. If you must go out, watch for fallen objects, downed electrical wires, and weakened walls, bridges, roads, and sidewalks. 7. Keep away from loose or dangling power lines and report them immediately to the power company. 8. Walk carefully around the outside your home and check for loose power lines, gas leaks, and structural damage before entering. 9. Stay out of any building if you smell gas, floodwaters remain around the building, or your home was damaged by fire and the authorities have not declared it safe. 10. Inspect your home for damage. If you have any doubts about safety, have your residence inspected by a qualified building inspector or structural engineer before entering. 11. Use battery-powered flashlights in the dark. Do not use candles. 12. Watch your pets closely and keep them under your direct control. Use a stick to poke through debris. 13. Avoid drinking or preparing food with tap water unit you are sure it is not contaminated. 14. Check refrigerated food for spoilage. 15. Wear protective clothing and be cautious when cleaning up to avoid injury. 16. Use the telephone only for emergency calls. 17. Never use a generator inside homes, garages, crawl spaces, sheds, or similar areas, even when using fans or opening doors and windows for ventilation. Top Provinces at Risk to Typhoons: 1. Cagayan 2. Albay 3. Ifugao 4. Sorsogon 5. Ilocos Sur 6. Ilocos Norte 7. Camarines Norte 8. Mountain Province 9. Camarines Sur 10.Northern Samar Top Provinces at Risk to Typhoons: 11.Catanduanes 12.Kalinga Apayao 13.Pampanga 14.La Union 15.Nueva Ecija 16.Pangasinan 17.Masbate 18.Tarlac 19.Western Samar Top 10 Flood Prone Provinces: 1. Pampanga 2. Nueva Ecija 3. Pangasinan 4. Tarlac 5. Maguindanao 6. Bulacan 7. Metro Manila 8. North Cotabato 9. Oriental Mindoro 10. Ilocos Norte Storm Surge II. Storm Surge Storm surge is the abnormal increase in the water level in seashore when a storm nears coastal line. It is caused by strong winds brought about by low pressure at the eye of the storm.  Before A Storm Surge 1. Know if your area is at risk. 2. Know the types of hazards that could affect your home and family. 3. Assess your risks and identify ways to make your home and property ore secure. Make a disaster evacuation plan. 4. If you live close to the floodplain, consider flood insurance. 5. Locate the safest areas in your home, and decide on an escape route should you need to evacuate.  During A Storm Surge 1. Monitor radio and television for the latest news and advisories. 2. If local officials ask you to evacuate, do so immediately. 3. Stay away from floodwaters. If you come upon a flowing stream where water is above your ankles, stop, turn around, and go another way. 4. Keep children out of water. 5. If you come upon a flooded road while driving, do not attempt to cross flowing water. After A Storm Surge 1. Return home only when officials have declared the area safe. 2. During clean-up, wear protective clothing, including gloves and boots. Make sure your food and water are safe. 3. Do not use water that could be contaminated to wash dishes, brush teeth, prepare food, wash hands, make ice or make baby formula. Tsunami III. Tsunamis Tsunamis, also known as seismic sea waves, are series of enormous waves created by an underwater disturbance such as an earthquake, landslides, volcanic eruption, or meteorite. If a major earthquake occurs close to the shore, the first wave in a series could reach the beach in a few minutes, even before a warning issued. Drowning is the most common cause of death associated with a tsunami. A. Tsunami Warning – is issued when a tsunami with the potential to generate widespread inundation is imminent or expected. B. Tsunami Advisory – is issued when a tsunami with the potential to generate strong currents or waves dangerous to those in or very near the water is imminent or expected. C. Tsunami Watch – is issued to alert emergency management officials and the public of an event which may later impact the watch area. Effects Of Marine And Coastal Processes ❖ Oceanography – the scientific field dealing with processes happening in our major oceans and seas. ❖Coastal processes are activities or events happening in the marine environment. These are driven by the different environmental factors such as atmospheric pressure, temperature, movement of the Earth, moon, and other dynamic changes in the ocean. ❖ Coastal processes include waves, tides, sea level change, crustal movement, and storm surge. ❖Waves are caused by the movement of the air masses in the coastal environment. ❖Tides refer to the gravitational pull between the Earth and the moon. ❖Sea level change is a result of the rise of ocean water which can be attributed to the melting of glaciers or iceberg in the polar regions. ❖Storm surge refers to the rising of seawater due to changes in pressure and wind associated with a storm. ❖Crustal movement is caused by the motion of the oceanic and continental crust of the Earth. ❖The different coastal processes may result to coastal hazards. ❖Coastal hazards are physical phenomena that expose the marine environment to risk of property damage, loss of life and ecological degradation. A. Coastal Erosion It is the loss or displacement of land along the coastline due to the action of waves, currents, tides, wind-driven water, or other impacts of storms. Coastal erosion is a type of coastal hazard which is brought about by the different coastal processes. B. Saltwater Intrusion Saltwater intrusion is the induced flow of seawater into freshwater aquifers primarily caused by groundwater development near the coast. C. Submersion It refers to the movement of coastal sediments from the visible portion of a beach to the submerged nearshore region of the coast.