TYPES OF HYDROMETEOROLOGICAL HAZARD.pptx

hydrometeorological hazards

1. https://quizizz.com/admin/quiz/60a138cb47f11c001c1d85e1/landslides-and-sinkholes

2. TORNADO

3. FLOOD

4. TYPHOON

5. DROUGHT

6. STORM SURGE

7. THUNDERSTORM

8. What does the acronym PAGASA stand for? Philippine Atmospheric, Geophysical, and Astronomical Services Administration What information can we get from PAGASA? PAGASA is the Philippine national institution dedicated to provide flood and typhoon warnings, public weather forecasts and advisories, meteorological, astronomical, climatological, and other specialized information and services primarily for the protection of life and property and in support of economic, productivity and sustainable development. 

9. Have you experience a similar event? Is your school/home at risk of experiencing similar hydrometeorological hazard?

10. Hydrometeorological phenomena are essential to life on Earth. It can be both beneficial and detrimental. Water is life and it is because of the Earth’s hydrological cycle that we get the water we use in everyday life, however, changes brought about by this cycle can be hazardous as well.

11. Hydrometeorology is the study of the atmospheric and terrestrial phases of the hydrological cycle with emphasis on the interrelationship between them. It deals with the transfer of water and energy between land surface and the lower atmosphere. Because the hydrological cycle is a cycle, it does not necessarily have a starting or ending point .

12. PROCESSES OF THE HYDROLOGIC CYCLE Precipitation A. Cloud formation and type B. Rainfall C. Associated hazards Formation of snow covered mountain tops (not applicable in the Philippines) Melting of snow and ice (not applicable in the Philippines) Interception of precipitation by vegetation cover Storage in land surface depressions Infiltration of water into soil Evapotranspiration Recharge of groundwater River runoff

13. CLOUDS Clouds are so common that most of the time people do not pay attention to it. There are cloud appreciation societies worldwide that encourage people to look at clouds. Cloud spotting is an activity that can be informative to the learners and teachers alike. Clouds are essential in the hydrologic cycle of Earth because their formation and movement initiates the transport of water. A cloud is a visible aggregate of small water droplets and/or ice particles in the atmosphere above earth’s surface and they form in the atmosphere as a result of condensation of water vapor rising from the surface. There are 10 general cloud types and they are classified depending of their height (low, mid and high), appearance and their corresponding precipitation.

14. Nimbus refers to rain producing clouds, hence the two general type of rain producing clouds have the word nimbus in it, namely: Cumulonimbus (thunderstorm clouds) Nimbostratus (continuous rain cloud). Clouds are associated with different types of precipitation and distinguishing between cloud types can give us a glimpse of an impending hydrometeorological hazard.

15. RAINFALL Rain is liquid water in the form of droplets that have condensed from atmospheric water vapor and then become heavy enough to fall under gravity.  Rain is a major component of the water cycle and is responsible for depositing most of the fresh water on the Earth. The types of rainfall based on intensity can be classified as: Light Rain – Rate of rain varies between 0 to 2.5 millimeters Moderate Rain – Rate of rain varies between 2.6 millimeters to 7.6 millimeters Heavy Rain –  Rate of rain is beyond 7.6 millimeters

16. HOW IS RAIN MEASURED? Rainfall is measured using a rain gauge. Rain gauge is thought to be one of the oldest weather instruments. Rain gauges can be as simple as a cylinder that catches rain water. The height of rain water that collects in the cylinder is the measured amount of rainfall, usually expressed in millimeters.

17. TERRESTRIAL PHASE OF WATER CYCLE As water returns to the surface of the Earth from precipitation, it doesn’t just stay in one place, gravity takes it to the ground either as infiltration , or it begins running downhill as surface runoff . Most of this moving water will end up in streams or rivers flowing towards the ocean. Since the Philippines is composed of islands with complex topography and mountainous regions, certain processes happen while water flows through land .

18. PROCESSES THAT GOVERN TERRESTRIAL WATER FLOW 1. Interception of precipitation by vegetation cover Before reaching the land surface, a part of the precipitation may be intercepted by vegetation and/or other types of surface cover. A portion of intercepted rainfall evaporates and the other portion may flow down on vegetation stems. 2. Storage in land surface depressions While most waters flows back to the ocean, some can flow in streams towards closed lake, or purposely diverted for human use, and stored there for a time.

19. PROCESSES THAT GOVERN TERRESTRIAL WATER FLOW 3. Infiltration of water into soil Infiltration is the flow of water through the soil surface. The rate of infiltration depends on certain soil properties like texture, structure and moisture content. Soil profiles, or the vertical organization of the different soil layers and the depth of the soil column, also influence the hydrologic processes as infiltration rates will vary with different soil. 4. Recharge of groundwater 5. River runoff

20. TROPICAL CYCLONES Tropical cyclone is a rotating, organized system of clouds and thunderstorms that originates over the tropical waters. Tropical cyclones rotate in a counterclockwise direction in the northern hemisphere and clockwise in the southern hemisphere. Every year, an average of 19 tropical cyclones enter the Philippines Area of Responsibility (PAR), and about half (9-10) make landfall in the Philippines.

21. TROPICAL CYCLONES A tropical cyclone can be seen in a satellite image due to its characteristic spiral/circular shape. The stronger and more intense a tropical cyclone becomes, the more symmetrical the inner clouds or rain bands are and a distinctive “eye” at the center of circulation becomes visible. This means that a tropical cyclone tends to be more circular and it’s center will have a cloudless region. Weather forecasters use satellite images to track the movement and estimate the intensity of tropical cyclones.

22. TROPICAL CYCLONES Another way weather forecasters track the movement of tropical cyclones is with the use of weather Radars. RADAR is an acronym which stands for RAdio Detection And Ranging . A Radar sends out electromagnetic waves to the atmosphere that is then reflected by hydrometeors (e.g. rain, clouds) present in the sky. An image is created from the received signal and information on rain clouds can be gathered. While radar images give more details of a storm, it is limited to a range of approximately 400 km from the radar site.

23. TROPICAL CYCLONES Once a tropical cyclone enters PAR, a 5-day forecast track (previously 3-day) is issued by PAGASA every 6 hours at 5am, 11am, 5pm and 11pm. A forecast track gives the expected location of a tropical cyclone in the succeeding 24- hour interval for the next 120 hours or 5 days. Together with the forecast track, PAGASA also issues the Public Storm Warning System (PSWS) to warn citizens of impending wind strength.

24. SIGNS OF HYDROMETEOROLOGICAL HAZARDS

25. TROPICAL CYCLONES Tropical cyclones are hydrometeorological hazards characterized by strong winds and heavy rain. Every year, an average of 19 tropical cyclones enter the Philippine Area of Responsibility and approximately 9-10 make landfall in the Philippines. This is because the Philippines is located on the western rim of the Pacific Ocean, where most tropical cyclones pass. Tropical cyclones can have a forecast lead time of 5 days.

26. THUNDERSTORMS Thunderstorms are generally local storms produced by cumulonimbus clouds and are always accompanied by lightning and thunder, usually with strong wind gusts, heavy rain and sometimes with hail and/or tornado. Thunderstorms are typical in warm environments like the tropics and may persist for 1 to 2 hours.

27. FLOOD Flood is the overflowing of the normal confines of a stream or bodies of water, or the accumulation of water over areas that are not normally submerged. While flooding may last days or even weeks, Flash Floods are also caused by heavy precipitation in a short period of time, usually less than 6 hours.

28. STORM SURGE Storm surge is the rise and onshore surge of seawater as the result primarily of the winds of a tropical cyclone, and secondarily of the surface pressure drop near the center of the tropical cyclone. The height of storm surge is dependent on the size, intensity and movement of the tropical cyclone, shape of the coastline as well as nearshore underwater topography and astronomical tides.

29. EL NINO El Niño is a significant increase in ocean temperature over the eastern and central Pacific ocean. It occurs at irregular intervals ranging from 2-7 years usually developing in the early months of the year and decay the following year. In the Philippines, El Niño conditions are often characterized by dry and warm-hot events.