Gale Warning in PDF file 
General Flood Advisories
This advisory is issued for the non- telemetered river basins. It is done as situation warrants (e.g. during inclement weather affecting the river basins in the particular region) . Normally it is issued at 7:00 AM and 7:00 PM.
Contents:
a. Present weather situation – describes the current weather system affecting the country based on the weather advisory issued by the weather forecasting section
b. Forecast 12-hour rainfall - gives the forecast rainfall for the next 12 hours based on all available models (e.g. Light, moderate, heavy)
c. List of watercourses that are likely to be affected – gives the list of all the tributaries that will be affected given the forecast rainfall in the particular region.
d. Public warning – describes the suggested actions as to what the people and (local) disaster risk reduction and management council would do.
Preparation of Flood Forecast
The preparation, issuance and dissemination of an adequate and timely warning is the ultimate purpose of flood forecasting. Timeliness is an essential requirement for a flood warning. A sufficient lead time enables the ultimate user to take the necessary precautionary countermeasures.
The hydrological and meteorological conditions in a river basin and the consequent state of its river system is never constant. The behavior of the river itself is the resultant of the interaction of all hydrological processes and conditions in the river basin.
A flooding situation is not a daily occurrence. However, flood forecasting operations must, of necessity, be a continuous activity. It is carried out from day to day even when the possibility of a flood is highly improbable. This mode of operation enables flood forecasters to pinpoint the beginning of a potential flood-generating situation.
Like storm bulletins which are issued only during the presence of tropical cyclones, flood forecast and warning bulletins are prepared only when a potential flooding situation is definitely present. They are issued regularly at specified hours of the day for the duration of the flooding period until the flood recedes or when all hazards and dangers associated with the phenomenon are no longer present.
The prevailing hydrometeorological situation in a given river basin defines the operational environment under which flood forecasting and warning operations are carried out. Conveniently categorized into
In practice1 flood bulletins are issued as soon as the development of a flooding situation exists. The initial bulletin serves merely to alert the people in the threatened basin to the possibility of a flood. It is never intended to categorically state that there will be flooding but only of the possibility. The initial bulletin is issued as soon as the operational situation passes from the alert to the warning phase. The transition from one operatiohal status to another is based on pre-determined criteria.
Thus, flood forecasting operation needs to be a continuing activity to determine the point in time when the operational situation passes from one phase to another. A flood forecasting operation consists of the following:
Monitoring:
This requires the collection, at regular interval, of the real-time data on rainfall, water level and other information that affect the hydrological condition of the river basin and the state of the river system. This provides a broad picture of the current situation in a river basin.
Analysis:
The data are analysed and related to other available information such as storm data from radar and satellite observation. The general objective here is to deduce the probable development in the hydrological situation in the river basin in the near future. This part of the operation involves a variety of hydrological analyses as well as the use of flood forecasting models to provide an objective estimate of the forecast situation.
Preparation of the forecast and warning:
Flood forecasts are completed in time for release at regular preset time of issuance. Dissemination is made through disseminating agencies such as the OCD1 DSWD, NDCC, and thru the mass media, particularly radio and television.
There are three categories of flood information intended for the general public. All are issued under the general title of "Flood Bulletin". A distinct series of bulletins is issued for each threatened river basin where the forecasting and warning service is already extended and operational. As already stated, bulletins are issued only when conditions,
i.e., there is a potential flooding situation, so warrant their issuance.
When required, flood bulletins are prepared twice daily. They are completed and readied for issuance and dissemination at 5 a.rn. and 5 p.rn., respectively, when it is deemed early enough to provide vital information for concerned users to take necessary countermeasures before they leave for work in the morning or before they retire at night.
A series of bulletins for a given affected river basin is ideally initiated by a Flood Outlook. As the category implies, the bulletin merely states the present hydrological situation and alerts the people in a basin to the possibility of a deteriorating condition, e.g., a gradual and continuous rise in the water level.
Subsequent bulletins could be of any one of the three categories. Normally, for a given affected basin, one bulletin is followed by another of the same in the next higher category depending on the development in the hydrological condition and the forecast situation. Hence, an Outlook is followed by another Outlook or by a Flood Advisory; or by a Flood Warning.
When the situation had clearly reached its worst such that, at most the condition or, at best, improvement can be expected, subsequent bulletins are of the same or by a next lower category than the proceeding.
Upon receipt of the coded messages, they are decoded and each set of observations is plotted in symbols or numbers on weather charts over the respective areas or regions. Observations made over land and sea are plotted on the surface or mean sea level charts which are prepared four times a day. Radiosonde, theodolite, aircraft and satellite wind observations are plotted on upper level charts which are prepared twice daily.
Flood bulletins are specifically directed to the public. They are intended to apprise the people in the threatened area of the present situation and of the expected development. It suggests the appropriate actions the community may have to take to prevent or mitigate the disastrous effects of a flood.
As in any kind of disaster, the best countermeasures for flood damage prevention and mitigation are those which are community efforts.
Floods cannot be prevented. To a large extent, however, they can be controlled effectively. By this is meant keeping the river from overflowing. There are a number of ways of accomplishing this before and during a flood:
Individually and collectively, people in a flood-stricken area must take precautionary measures to ensure personnel safety and health:
Flood Safety Rules
BEFORE THE FLOOD:
THINGS ONE CAN DO TO MITIGATE FLOODS:
This advisory is issued for the non- telemetered river basins. It is done as situation warrants (e.g. during inclement weather affecting the river basins in the particular region) . Normally it is issued at 7:00 AM and 7:00 PM.
Contents:
a. Present weather situation – describes the current weather system affecting the country based on the weather advisory issued by the weather forecasting section
b. Forecast 12-hour rainfall - gives the forecast rainfall for the next 12 hours based on all available models (e.g. Light, moderate, heavy)
c. List of watercourses that are likely to be affected – gives the list of all the tributaries that will be affected given the forecast rainfall in the particular region.
d. Public warning – describes the suggested actions as to what the people and (local) disaster risk reduction and management council would do.
Preparation of Flood Forecast
The preparation, issuance and dissemination of an adequate and timely warning is the ultimate purpose of flood forecasting. Timeliness is an essential requirement for a flood warning. A sufficient lead time enables the ultimate user to take the necessary precautionary countermeasures.
The hydrological and meteorological conditions in a river basin and the consequent state of its river system is never constant. The behavior of the river itself is the resultant of the interaction of all hydrological processes and conditions in the river basin.
A flooding situation is not a daily occurrence. However, flood forecasting operations must, of necessity, be a continuous activity. It is carried out from day to day even when the possibility of a flood is highly improbable. This mode of operation enables flood forecasters to pinpoint the beginning of a potential flood-generating situation.
Like storm bulletins which are issued only during the presence of tropical cyclones, flood forecast and warning bulletins are prepared only when a potential flooding situation is definitely present. They are issued regularly at specified hours of the day for the duration of the flooding period until the flood recedes or when all hazards and dangers associated with the phenomenon are no longer present.
The prevailing hydrometeorological situation in a given river basin defines the operational environment under which flood forecasting and warning operations are carried out. Conveniently categorized into
- normal situation,
- alert phase, and
- warning phase
In practice1 flood bulletins are issued as soon as the development of a flooding situation exists. The initial bulletin serves merely to alert the people in the threatened basin to the possibility of a flood. It is never intended to categorically state that there will be flooding but only of the possibility. The initial bulletin is issued as soon as the operational situation passes from the alert to the warning phase. The transition from one operatiohal status to another is based on pre-determined criteria.
Thus, flood forecasting operation needs to be a continuing activity to determine the point in time when the operational situation passes from one phase to another. A flood forecasting operation consists of the following:
Monitoring:
This requires the collection, at regular interval, of the real-time data on rainfall, water level and other information that affect the hydrological condition of the river basin and the state of the river system. This provides a broad picture of the current situation in a river basin.
Analysis:
The data are analysed and related to other available information such as storm data from radar and satellite observation. The general objective here is to deduce the probable development in the hydrological situation in the river basin in the near future. This part of the operation involves a variety of hydrological analyses as well as the use of flood forecasting models to provide an objective estimate of the forecast situation.
Preparation of the forecast and warning:
Flood forecasts are completed in time for release at regular preset time of issuance. Dissemination is made through disseminating agencies such as the OCD1 DSWD, NDCC, and thru the mass media, particularly radio and television.
There are three categories of flood information intended for the general public. All are issued under the general title of "Flood Bulletin". A distinct series of bulletins is issued for each threatened river basin where the forecasting and warning service is already extended and operational. As already stated, bulletins are issued only when conditions,
i.e., there is a potential flooding situation, so warrant their issuance.
When required, flood bulletins are prepared twice daily. They are completed and readied for issuance and dissemination at 5 a.rn. and 5 p.rn., respectively, when it is deemed early enough to provide vital information for concerned users to take necessary countermeasures before they leave for work in the morning or before they retire at night.
A series of bulletins for a given affected river basin is ideally initiated by a Flood Outlook. As the category implies, the bulletin merely states the present hydrological situation and alerts the people in a basin to the possibility of a deteriorating condition, e.g., a gradual and continuous rise in the water level.
Subsequent bulletins could be of any one of the three categories. Normally, for a given affected basin, one bulletin is followed by another of the same in the next higher category depending on the development in the hydrological condition and the forecast situation. Hence, an Outlook is followed by another Outlook or by a Flood Advisory; or by a Flood Warning.
When the situation had clearly reached its worst such that, at most the condition or, at best, improvement can be expected, subsequent bulletins are of the same or by a next lower category than the proceeding.
Upon receipt of the coded messages, they are decoded and each set of observations is plotted in symbols or numbers on weather charts over the respective areas or regions. Observations made over land and sea are plotted on the surface or mean sea level charts which are prepared four times a day. Radiosonde, theodolite, aircraft and satellite wind observations are plotted on upper level charts which are prepared twice daily.
Flood bulletins are specifically directed to the public. They are intended to apprise the people in the threatened area of the present situation and of the expected development. It suggests the appropriate actions the community may have to take to prevent or mitigate the disastrous effects of a flood.
As in any kind of disaster, the best countermeasures for flood damage prevention and mitigation are those which are community efforts.
Floods cannot be prevented. To a large extent, however, they can be controlled effectively. By this is meant keeping the river from overflowing. There are a number of ways of accomplishing this before and during a flood:
- increasing the flow capacity of a river by cleaning the channel of debris, by dredging, by straightening of channels, etc.;
- construction of dikes and levees; and
- sandbagging during floods.
Individually and collectively, people in a flood-stricken area must take precautionary measures to ensure personnel safety and health:
- People, particularly children, should avoid wading in floodwaters.
- Where houses are expected to be flooded, people should move to higher places.
- Electrically operated appliances should be transferred to upper storeys of buildings.
- When electrical fines and outlets will be submerged in floodwater, power should be switched off.
Flood Safety Rules
BEFORE THE FLOOD:
- Find out how often your location is likely to be flooded.
- Know the flood warning system in your community and be sure your family knows it.
- Keep informed of daily weather condition.
- Designate an evacuation area for the family and livestock.
- Assign family members instructions and responsibilities according to an evacuation plan.
- Keep a stock of food which requires little cooking and refrigeration; electric power may be interrupted.
- Keep a transistorized radio and flashlight with spare batteries, emergency cooking equipment, candies, matches and first aid kit handy in case of emergency.
- Store supplies and other household effects above expected flood water level.
- Securely anchor weak dwellings and items.
- Watch for rapidly rising flood waters.
- Listen to your radio for emergency instructions.
- If you find it necessary to evacuate, move to a safe area before access is cut off by flood waters.
- Store drinking water in containers, water service may be interrupted.
- Move household belongings to upper levels.
- Get livestock to higher ground.
- Turn off electricity at the main switch in the building before evacuating and also lock your house.
- Avoid areas subject to sudden flooding.
- Do not attempt to cross rivers of flowing streams where water is above the knee.
- Beware of water-covered roads and bridges.
- Avoid unnecessary exposure to the elements.
- Do not go swimming or boating in swollen rivers.
- Eat only well-cooked food. Protect leftovers against contamination.
- Drink clean or preferably boiled water ONLY.
- Re-enter the dwellings with caution using flashlights, not lanterns or torchers. Flammables may be inside.
- Be alert for fire hazards like broken wires.
- Do not eat food and drink water until they have been checked for flood water contamination.
- Report broken utility lines (electricity, water, gas and telephone) to appropriate agencies authorities.
- Do not turn on the main switch or use appliances and other equipment until they have been checked by a competent electrician.
- Consult health authorities for immunization requirements.
- Do not go in disaster areas. Your presence might hamper rescue and other emergency operations
THINGS ONE CAN DO TO MITIGATE FLOODS:
- Regulate cutting of trees.
- Report illegal loggers and kaingeros.
- Report illegal construction of fishponds and other establishments in waterways.
- Do not throw garbage in esteros and rivers.
- Help clean the neighborhood.
- Support community activities intended to lessen the occurrence of floods.
- Avoid throwing anything like plastic wrappers anywhere which may clog or block the drainage system.
General Flood Advisories
This advisory is issued for the non- telemetered river basins. It is done as situation warrants (e.g. during inclement weather affecting the river basins in the particular region) . Normally it is issued at 7:00 AM and 7:00 PM.
Contents:
a. Present weather situation – describes the current weather system affecting the country based on the weather advisory issued by the weather forecasting section
b. Forecast 12-hour rainfall - gives the forecast rainfall for the next 12 hours based on all available models (e.g. Light, moderate, heavy)
c. List of watercourses that are likely to be affected – gives the list of all the tributaries that will be affected given the forecast rainfall in the particular region.
d. Public warning – describes the suggested actions as to what the people and (local) disaster risk reduction and management council would do.
Preparation of Flood Forecast
The preparation, issuance and dissemination of an adequate and timely warning is the ultimate purpose of flood forecasting. Timeliness is an essential requirement for a flood warning. A sufficient lead time enables the ultimate user to take the necessary precautionary countermeasures.
The hydrological and meteorological conditions in a river basin and the consequent state of its river system is never constant. The behavior of the river itself is the resultant of the interaction of all hydrological processes and conditions in the river basin.
A flooding situation is not a daily occurrence. However, flood forecasting operations must, of necessity, be a continuous activity. It is carried out from day to day even when the possibility of a flood is highly improbable. This mode of operation enables flood forecasters to pinpoint the beginning of a potential flood-generating situation.
Like storm bulletins which are issued only during the presence of tropical cyclones, flood forecast and warning bulletins are prepared only when a potential flooding situation is definitely present. They are issued regularly at specified hours of the day for the duration of the flooding period until the flood recedes or when all hazards and dangers associated with the phenomenon are no longer present.
The prevailing hydrometeorological situation in a given river basin defines the operational environment under which flood forecasting and warning operations are carried out. Conveniently categorized into
In practice1 flood bulletins are issued as soon as the development of a flooding situation exists. The initial bulletin serves merely to alert the people in the threatened basin to the possibility of a flood. It is never intended to categorically state that there will be flooding but only of the possibility. The initial bulletin is issued as soon as the operational situation passes from the alert to the warning phase. The transition from one operatiohal status to another is based on pre-determined criteria.
Thus, flood forecasting operation needs to be a continuing activity to determine the point in time when the operational situation passes from one phase to another. A flood forecasting operation consists of the following:
Monitoring:
This requires the collection, at regular interval, of the real-time data on rainfall, water level and other information that affect the hydrological condition of the river basin and the state of the river system. This provides a broad picture of the current situation in a river basin.
Analysis:
The data are analysed and related to other available information such as storm data from radar and satellite observation. The general objective here is to deduce the probable development in the hydrological situation in the river basin in the near future. This part of the operation involves a variety of hydrological analyses as well as the use of flood forecasting models to provide an objective estimate of the forecast situation.
Preparation of the forecast and warning:
Flood forecasts are completed in time for release at regular preset time of issuance. Dissemination is made through disseminating agencies such as the OCD1 DSWD, NDCC, and thru the mass media, particularly radio and television.
There are three categories of flood information intended for the general public. All are issued under the general title of "Flood Bulletin". A distinct series of bulletins is issued for each threatened river basin where the forecasting and warning service is already extended and operational. As already stated, bulletins are issued only when conditions,
i.e., there is a potential flooding situation, so warrant their issuance.
When required, flood bulletins are prepared twice daily. They are completed and readied for issuance and dissemination at 5 a.rn. and 5 p.rn., respectively, when it is deemed early enough to provide vital information for concerned users to take necessary countermeasures before they leave for work in the morning or before they retire at night.
A series of bulletins for a given affected river basin is ideally initiated by a Flood Outlook. As the category implies, the bulletin merely states the present hydrological situation and alerts the people in a basin to the possibility of a deteriorating condition, e.g., a gradual and continuous rise in the water level.
Subsequent bulletins could be of any one of the three categories. Normally, for a given affected basin, one bulletin is followed by another of the same in the next higher category depending on the development in the hydrological condition and the forecast situation. Hence, an Outlook is followed by another Outlook or by a Flood Advisory; or by a Flood Warning.
When the situation had clearly reached its worst such that, at most the condition or, at best, improvement can be expected, subsequent bulletins are of the same or by a next lower category than the proceeding.
Upon receipt of the coded messages, they are decoded and each set of observations is plotted in symbols or numbers on weather charts over the respective areas or regions. Observations made over land and sea are plotted on the surface or mean sea level charts which are prepared four times a day. Radiosonde, theodolite, aircraft and satellite wind observations are plotted on upper level charts which are prepared twice daily.
Flood bulletins are specifically directed to the public. They are intended to apprise the people in the threatened area of the present situation and of the expected development. It suggests the appropriate actions the community may have to take to prevent or mitigate the disastrous effects of a flood.
As in any kind of disaster, the best countermeasures for flood damage prevention and mitigation are those which are community efforts.
Floods cannot be prevented. To a large extent, however, they can be controlled effectively. By this is meant keeping the river from overflowing. There are a number of ways of accomplishing this before and during a flood:
Individually and collectively, people in a flood-stricken area must take precautionary measures to ensure personnel safety and health:
Flood Safety Rules
BEFORE THE FLOOD:
THINGS ONE CAN DO TO MITIGATE FLOODS:
This advisory is issued for the non- telemetered river basins. It is done as situation warrants (e.g. during inclement weather affecting the river basins in the particular region) . Normally it is issued at 7:00 AM and 7:00 PM.
Contents:
a. Present weather situation – describes the current weather system affecting the country based on the weather advisory issued by the weather forecasting section
b. Forecast 12-hour rainfall - gives the forecast rainfall for the next 12 hours based on all available models (e.g. Light, moderate, heavy)
c. List of watercourses that are likely to be affected – gives the list of all the tributaries that will be affected given the forecast rainfall in the particular region.
d. Public warning – describes the suggested actions as to what the people and (local) disaster risk reduction and management council would do.
Preparation of Flood Forecast
The preparation, issuance and dissemination of an adequate and timely warning is the ultimate purpose of flood forecasting. Timeliness is an essential requirement for a flood warning. A sufficient lead time enables the ultimate user to take the necessary precautionary countermeasures.
The hydrological and meteorological conditions in a river basin and the consequent state of its river system is never constant. The behavior of the river itself is the resultant of the interaction of all hydrological processes and conditions in the river basin.
A flooding situation is not a daily occurrence. However, flood forecasting operations must, of necessity, be a continuous activity. It is carried out from day to day even when the possibility of a flood is highly improbable. This mode of operation enables flood forecasters to pinpoint the beginning of a potential flood-generating situation.
Like storm bulletins which are issued only during the presence of tropical cyclones, flood forecast and warning bulletins are prepared only when a potential flooding situation is definitely present. They are issued regularly at specified hours of the day for the duration of the flooding period until the flood recedes or when all hazards and dangers associated with the phenomenon are no longer present.
The prevailing hydrometeorological situation in a given river basin defines the operational environment under which flood forecasting and warning operations are carried out. Conveniently categorized into
- normal situation,
- alert phase, and
- warning phase
In practice1 flood bulletins are issued as soon as the development of a flooding situation exists. The initial bulletin serves merely to alert the people in the threatened basin to the possibility of a flood. It is never intended to categorically state that there will be flooding but only of the possibility. The initial bulletin is issued as soon as the operational situation passes from the alert to the warning phase. The transition from one operatiohal status to another is based on pre-determined criteria.
Thus, flood forecasting operation needs to be a continuing activity to determine the point in time when the operational situation passes from one phase to another. A flood forecasting operation consists of the following:
Monitoring:
This requires the collection, at regular interval, of the real-time data on rainfall, water level and other information that affect the hydrological condition of the river basin and the state of the river system. This provides a broad picture of the current situation in a river basin.
Analysis:
The data are analysed and related to other available information such as storm data from radar and satellite observation. The general objective here is to deduce the probable development in the hydrological situation in the river basin in the near future. This part of the operation involves a variety of hydrological analyses as well as the use of flood forecasting models to provide an objective estimate of the forecast situation.
Preparation of the forecast and warning:
Flood forecasts are completed in time for release at regular preset time of issuance. Dissemination is made through disseminating agencies such as the OCD1 DSWD, NDCC, and thru the mass media, particularly radio and television.
There are three categories of flood information intended for the general public. All are issued under the general title of "Flood Bulletin". A distinct series of bulletins is issued for each threatened river basin where the forecasting and warning service is already extended and operational. As already stated, bulletins are issued only when conditions,
i.e., there is a potential flooding situation, so warrant their issuance.
When required, flood bulletins are prepared twice daily. They are completed and readied for issuance and dissemination at 5 a.rn. and 5 p.rn., respectively, when it is deemed early enough to provide vital information for concerned users to take necessary countermeasures before they leave for work in the morning or before they retire at night.
A series of bulletins for a given affected river basin is ideally initiated by a Flood Outlook. As the category implies, the bulletin merely states the present hydrological situation and alerts the people in a basin to the possibility of a deteriorating condition, e.g., a gradual and continuous rise in the water level.
Subsequent bulletins could be of any one of the three categories. Normally, for a given affected basin, one bulletin is followed by another of the same in the next higher category depending on the development in the hydrological condition and the forecast situation. Hence, an Outlook is followed by another Outlook or by a Flood Advisory; or by a Flood Warning.
When the situation had clearly reached its worst such that, at most the condition or, at best, improvement can be expected, subsequent bulletins are of the same or by a next lower category than the proceeding.
Upon receipt of the coded messages, they are decoded and each set of observations is plotted in symbols or numbers on weather charts over the respective areas or regions. Observations made over land and sea are plotted on the surface or mean sea level charts which are prepared four times a day. Radiosonde, theodolite, aircraft and satellite wind observations are plotted on upper level charts which are prepared twice daily.
Flood bulletins are specifically directed to the public. They are intended to apprise the people in the threatened area of the present situation and of the expected development. It suggests the appropriate actions the community may have to take to prevent or mitigate the disastrous effects of a flood.
As in any kind of disaster, the best countermeasures for flood damage prevention and mitigation are those which are community efforts.
Floods cannot be prevented. To a large extent, however, they can be controlled effectively. By this is meant keeping the river from overflowing. There are a number of ways of accomplishing this before and during a flood:
- increasing the flow capacity of a river by cleaning the channel of debris, by dredging, by straightening of channels, etc.;
- construction of dikes and levees; and
- sandbagging during floods.
Individually and collectively, people in a flood-stricken area must take precautionary measures to ensure personnel safety and health:
- People, particularly children, should avoid wading in floodwaters.
- Where houses are expected to be flooded, people should move to higher places.
- Electrically operated appliances should be transferred to upper storeys of buildings.
- When electrical fines and outlets will be submerged in floodwater, power should be switched off.
Flood Safety Rules
BEFORE THE FLOOD:
- Find out how often your location is likely to be flooded.
- Know the flood warning system in your community and be sure your family knows it.
- Keep informed of daily weather condition.
- Designate an evacuation area for the family and livestock.
- Assign family members instructions and responsibilities according to an evacuation plan.
- Keep a stock of food which requires little cooking and refrigeration; electric power may be interrupted.
- Keep a transistorized radio and flashlight with spare batteries, emergency cooking equipment, candies, matches and first aid kit handy in case of emergency.
- Store supplies and other household effects above expected flood water level.
- Securely anchor weak dwellings and items.
- Watch for rapidly rising flood waters.
- Listen to your radio for emergency instructions.
- If you find it necessary to evacuate, move to a safe area before access is cut off by flood waters.
- Store drinking water in containers, water service may be interrupted.
- Move household belongings to upper levels.
- Get livestock to higher ground.
- Turn off electricity at the main switch in the building before evacuating and also lock your house.
- Avoid areas subject to sudden flooding.
- Do not attempt to cross rivers of flowing streams where water is above the knee.
- Beware of water-covered roads and bridges.
- Avoid unnecessary exposure to the elements.
- Do not go swimming or boating in swollen rivers.
- Eat only well-cooked food. Protect leftovers against contamination.
- Drink clean or preferably boiled water ONLY.
- Re-enter the dwellings with caution using flashlights, not lanterns or torchers. Flammables may be inside.
- Be alert for fire hazards like broken wires.
- Do not eat food and drink water until they have been checked for flood water contamination.
- Report broken utility lines (electricity, water, gas and telephone) to appropriate agencies authorities.
- Do not turn on the main switch or use appliances and other equipment until they have been checked by a competent electrician.
- Consult health authorities for immunization requirements.
- Do not go in disaster areas. Your presence might hamper rescue and other emergency operations
THINGS ONE CAN DO TO MITIGATE FLOODS:
- Regulate cutting of trees.
- Report illegal loggers and kaingeros.
- Report illegal construction of fishponds and other establishments in waterways.
- Do not throw garbage in esteros and rivers.
- Help clean the neighborhood.
- Support community activities intended to lessen the occurrence of floods.
- Avoid throwing anything like plastic wrappers anywhere which may clog or block the drainage system.
The PAMPANGA RIVER BASIN
The 4th largest basin in the Philippines and covers an approximate aggregate area of 10,540 sq. km. (includes the allied basin of Guagua River). The basin extends over the southern slopes of the Caraballo Mountains, the western slopes of the Sierra Madre range and the major portions of the Central Plain of Luzon. It encompasses the provinces of Nueva Ecija; part of Bulacan, Tarlac and Quezon; and almost whole of Pampanga. The total length of the main river, the Pampanga River, is about 260 kilometers.
The basin is drained through the Pampanga River and via the Labangan Channel into the Manila Bay. The main river is supported by several tributaries, the principal ones of which are the Penaranda and the Coronel-Santor Rivers on the eastern side of the basin and the Rio Chico River from the northwest side. The Angat River joins the Pampanga River at Calumpit in Bulacan via the Bagbag River. The Labangan channel, on the other hand, acts as a cut-off channel for the Angat River into Manila Bay. Somewhere between the middle and lower portion of the basin stands Mount Arayat, about 1,026 meters in elevation. Adjacent to Mount Arayat, across Pampanga River, just on the eastern side is the Candaba swamp, covering an area of some 250 sq. km. absorbing most of the flood flows coming from the eastern sections of the basin (western slopes of a portion of the Sierra Madre mountain range) and the overflowing of the Pampanga River via the Cabiao Floodway. This area is submerged during the rainy season but is relatively dry during summer. At the lower sections of the basin, where the Pampanga delta lies, the Pampanga River system divide into relatively small branches, crisscrossed with fishponds to form a network of sluggish, tidal flats and canals, which eventually find their way to Manila Bay. The main river has a relatively low-gradient channel particularly at the middle and lower sections. With the anticipated completion of the Pampanga Delta Project (DPWH), it is expected that floodflows at the lower section of the Pampanga River will recede at a much faster rate than before.
The basin experiences, on an average, at least one flooding in a year. The dry season generally occurs from December to May, and wet the rest of the year. The wettest months are from July to September. The frequency of tropical cyclone passage over the basin is about 5 in 3 years. (Click for PRB website)
The AGNO RIVER BASIN
The Agno River, with a drainage area of 5,952 square kilometers is the third largest river in Luzon, fifth in the Philippines, next to the Cagayan and Pampanga Rivers. The length of the river system from its source in the Cordillera Mountains to its mouth in Lingayen Gulf is about 270 kilometers, 90 kilometers of which runs through mountainous terrain and canyons.
The Agno River after passing through mountains at an average elevation of some 2,000 above MSL, forms a vast alluvial fan and delta called the Pangasinan Plain and then flows into the Lingayen Gulf. The Pangasinan plain has long been economically developed and together with the Pampanga Plain constitute the rice granary of Central Luzon. Principal tributaries of the Agno River include the Pila, Camiling, Tarlac and Ambayoan Rivers. The main branch of the Agno River is Tarlac River which has its source at Mt. Pinatubo (elevation 1,745m) in Tarlac and joins the Agno River at Poponto Swamp near Bayambang. The swamp has an area of about 25 square kilometers and temporarily retains flood waters from the Tarlac River. Since the Agno River basin is characterized by mountainous topography, the flood runoff estimated annually at about 6,654 million cubic meters reaches the plain in several hours in the river mouth in about a day. Average annual rainfall varies from 2,000mm in the neighborhood of Tarlac to 4,000mm in the upper reaches of the Agno River. Such great variation in the area distribution of rainfall is attributed to orographic effect coupled with tropical cyclone and south-west monsoon rainfall.
The Pangasinan Plain suffers from recurrent and destructive floods. The catastrophic floods of July-August 1972 and May 1976 inundated the entire Pangasinan Plain including the flood plains of the Tarlac River.
The target areas for this flood forecasting and warning subsystem are:
a) The entire Pangasinan Plain including the major city/municipalities of Dagupan, Lingayen, Bugallon, Sta. Barbara, Bayambang and Rosales
b) The central part of Tarlac province including the municipalities of Gerona, Tarlac, Paniqui and Moncada.
The Agno River, with a drainage area of 5,952 square kilometers is the third largest river in Luzon, fifth in the Philippines, next to the Cagayan and Pampanga Rivers. The length of the river system from its source in the Cordillera Mountains to its mouth in Lingayen Gulf is about 270 kilometers, 90 kilometers of which runs through mountainous terrain and canyons.
The Agno River after passing through mountains at an average elevation of some 2,000 above MSL, forms a vast alluvial fan and delta called the Pangasinan Plain and then flows into the Lingayen Gulf. The Pangasinan plain has long been economically developed and together with the Pampanga Plain constitute the rice granary of Central Luzon. Principal tributaries of the Agno River include the Pila, Camiling, Tarlac and Ambayoan Rivers. The main branch of the Agno River is Tarlac River which has its source at Mt. Pinatubo (elevation 1,745m) in Tarlac and joins the Agno River at Poponto Swamp near Bayambang. The swamp has an area of about 25 square kilometers and temporarily retains flood waters from the Tarlac River. Since the Agno River basin is characterized by mountainous topography, the flood runoff estimated annually at about 6,654 million cubic meters reaches the plain in several hours in the river mouth in about a day. Average annual rainfall varies from 2,000mm in the neighborhood of Tarlac to 4,000mm in the upper reaches of the Agno River. Such great variation in the area distribution of rainfall is attributed to orographic effect coupled with tropical cyclone and south-west monsoon rainfall.The Pangasinan Plain suffers from recurrent and destructive floods. The catastrophic floods of July-August 1972 and May 1976 inundated the entire Pangasinan Plain including the flood plains of the Tarlac River.
The target areas for this flood forecasting and warning subsystem are:
a) The entire Pangasinan Plain including the major city/municipalities of Dagupan, Lingayen, Bugallon, Sta. Barbara, Bayambang and Rosales
b) The central part of Tarlac province including the municipalities of Gerona, Tarlac, Paniqui and Moncada.
The BICOL RIVER BASIN
The Bicol River is a medium-size river in Southern Luzon and drains an area of 3,771 square kilometers. Situated in the Bicol Peninsula, it embraces the central portion of Camarines Sur, the northern portion of Albay, and a portion of Camarines Norte. The basin is oriented in a northwest-southeast direction and bounded on the east by a chain of volcanoes and on the west by highlands and lowhills. The flat alluvial land in the Bicol Plain occupies the area between the Eastern Bicol Cordillera and the Ragay Hills.
The runoff which is estimated annually at 5,100 million cubic meters, starts from the Mayon Volcano with an elevation of 4,421m, and meanders in a generally northwestward direction. After being regulated through lakes Bato, Buhi, and Baao, the streamflow reaches the mainstream of the Bicol River which owing to its very gentle slope, is affected by tides as far as upstream of Naga City.
The Bicol River is a medium-size river in Southern Luzon and drains an area of 3,771 square kilometers. Situated in the Bicol Peninsula, it embraces the central portion of Camarines Sur, the northern portion of Albay, and a portion of Camarines Norte. The basin is oriented in a northwest-southeast direction and bounded on the east by a chain of volcanoes and on the west by highlands and lowhills. The flat alluvial land in the Bicol Plain occupies the area between the Eastern Bicol Cordillera and the Ragay Hills.
The runoff which is estimated annually at 5,100 million cubic meters, starts from the Mayon Volcano with an elevation of 4,421m, and meanders in a generally northwestward direction. After being regulated through lakes Bato, Buhi, and Baao, the streamflow reaches the mainstream of the Bicol River which owing to its very gentle slope, is affected by tides as far as upstream of Naga City.
The Cagayan River Basin
The Cagayan River is the largest river in the Philippines with a drainage area of 27,280 square kilometers at its mouth in Aparri.The basin encompasses parts of Cagayan, Isabela, Mountain Province, Nueva Vizcaya, Quirino and Quezon Provinces. The basin is roughly elliptical in shape with its major axis oriented in a north-south direction. The Cagayan Valley is relatively flat but mountains with elevations up to 2,000m surround the east, south and west of the drainage basin.
The Cagayan River, which is the main drainage channel of the basin, flows in a northerly direction from its head waters in Nueva Vizcaya to its mouth in the Babuyan Channel near Aparri. Its principal tributaries include the Siffu-Malling, Chico, Ilagan and Magat Rivers. The estimated annual discharge is 53,943 million cubic meters.The Magat River is the largest tributary with an estimated annual discharge of 9,808 million cubic meters. It lies in the southwestern portion of the basin, stretching approximately 150 kilometers from Nueva Vizcaya down to its confluence with Cagayan River about 55 kilometers from the river mouth. Both the Magat and the Chico Rivers have extensive drainage areas which comprise about 1/3 of the whole basin. The Ilagan River originates from the western slopes of the Sierra Madre and drains the eastern central portion of the Cagayan River basin with an estimated annual discharge of 9,455 million cubic meters. It flows westward and joins the Cagayan River at Ilagan, Isabela, 200 kilometers from the mouth. The Siffu-Malling River lies on the slope of the Central Cordillera ranges flowing almost parallel to the Magat River. Marshes and swamps are found in some parts of its lower reaches.The average annual rainfall in 1,000mm in the northern part and 3,000mm in the southern mountains. Floods caused by this river flow down very slowly because of surface retention over the extensive flood plain, extremely gentle slope, retardation of flood by several gorges and river meander.The target areas for the flood forecasting and warning system of the Cagayan River Basin are:a)The areas along the lower reaches, from Tuguegarao to Aparrib) The alluvial plain along the river course from Ilagan to Tumauini, Isabela.
General Flood Advisories
This advisory is issued for the non- telemetered river basins. It is done as situation warrants (e.g. during inclement weather affecting the river basins in the particular region) . Normally it is issued at 9:00 in the morning or 6:00 in the afternoon.
Contents:
a. Present weather situation – describes the current weather system affecting the country based on the weather advisory issued by the weather forecasting section
b. Forecast 24-hour rainfall - gives the forecast rainfall for the next 24 hours based on all available models (e.g. Light, moderate, heavy)
c. List of watercourses that are likely to be affected – gives the list of all the tributaries that will be affected given the forecast rainfall in the particular region.
d. Public warning – describes the suggested actions as to what the people and (local) disaster risk reduction and management council would do.
Preparation of Flood Forecast
The preparation, issuance and dissemination of an adequate and timely warning is the ultimate purpose of flood forecasting. Timeliness is an essential requirement for a flood warning. A sufficient lead time enables the ultimate user to take the necessary precautionary countermeasures.
The hydrological and meteorological conditions in a river basin and the consequent state of its river system is never constant. The behavior of the river itself is the resultant of the interaction of all hydrological processes and conditions in the river basin.
A flooding situation is not a daily occurrence. However, flood forecasting operations must, of necessity, be a continuous activity. It is carried out from day to day even when the possibility of a flood is highly improbable. This mode of operation enables flood forecasters to pinpoint the beginning of a potential flood-generating situation.
Like storm bulletins which are issued only during the presence of tropical cyclones, flood forecast and warning bulletins are prepared only when a potential flooding situation is definitely present. They are issued regularly at specified hours of the day for the duration of the flooding period until the flood recedes or when all hazards and dangers associated with the phenomenon are no longer present.
The prevailing hydrometeorological situation in a given river basin defines the operational environment under which flood forecasting and warning operations are carried out. Conveniently categorized into
In practice1 flood bulletins are issued as soon as the development of a flooding situation exists. The initial bulletin serves merely to alert the people in the threatened basin to the possibility of a flood. It is never intended to categorically state that there will be flooding but only of the possibility. The initial bulletin is issued as soon as the operational situation passes from the alert to the warning phase. The transition from one operatiohal status to another is based on pre-determined criteria.
Thus, flood forecasting operation needs to be a continuing activity to determine the point in time when the operational situation passes from one phase to another. A flood forecasting operation consists of the following:
Monitoring:
This requires the collection, at regular interval, of the real-time data on rainfall, water level and other information that affect the hydrological condition of the river basin and the state of the river system. This provides a broad picture of the current situation in a river basin.
Analysis:
The data are analysed and related to other available information such as storm data from radar and satellite observation. The general objective here is to deduce the probable development in the hydrological situation in the river basin in the near future. This part of the operation involves a variety of hydrological analyses as well as the use of flood forecasting models to provide an objective estimate of the forecast situation.
Preparation of the forecast and warning:
Flood forecasts are completed in time for release at regular preset time of issuance. Dissemination is made through disseminating agencies such as the OCD1 DSWD, NDCC, and thru the mass media, particularly radio and television.
There are three categories of flood information intended for the general public. All are issued under the general title of "Flood Bulletin". A distinct series of bulletins is issued for each threatened river basin where the forecasting and warning service is already extended and operational. As already stated, bulletins are issued only when conditions,
i.e., there is a potential flooding situation, so warrant their issuance.
When required, flood bulletins are prepared twice daily. They are completed and readied for issuance and dissemination at 5 a.rn. and 5 p.rn., respectively, when it is deemed early enough to provide vital information for concerned users to take necessary countermeasures before they leave for work in the morning or before they retire at night.
A series of bulletins for a given affected river basin is ideally initiated by a Flood Outlook. As the category implies, the bulletin merely states the present hydrological situation and alerts the people in a basin to the possibility of a deteriorating condition, e.g., a gradual and continuous rise in the water level.
Subsequent bulletins could be of any one of the three categories. Normally, for a given affected basin, one bulletin is followed by another of the same in the next higher category depending on the development in the hydrological condition and the forecast situation. Hence, an Outlook is followed by another Outlook or by a Flood Advisory; or by a Flood Warning.
When the situation had clearly reached its worst such that, at most the condition or, at best, improvement can be expected, subsequent bulletins are of the same or by a next lower category than the proceeding.
Upon receipt of the coded messages, they are decoded and each set of observations is plotted in symbols or numbers on weather charts over the respective areas or regions. Observations made over land and sea are plotted on the surface or mean sea level charts which are prepared four times a day. Radiosonde, theodolite, aircraft and satellite wind observations are plotted on upper level charts which are prepared twice daily.
Flood bulletins are specifically directed to the public. They are intended to apprise the people in the threatened area of the present situation and of the expected development. It suggests the appropriate actions the community may have to take to prevent or mitigate the disastrous effects of a flood.
As in any kind of disaster, the best countermeasures for flood damage prevention and mitigation are those which are community efforts.
Floods cannot be prevented. To a large extent, however, they can be controlled effectively. By this is meant keeping the river from overflowing. There are a number of ways of accomplishing this before and during a flood:
Individually and collectively, people in a flood-stricken area must take precautionary measures to ensure personnel safety and health:
Flood Safety Rules
BEFORE THE FLOOD:
THINGS ONE CAN DO TO MITIGATE FLOODS:
This advisory is issued for the non- telemetered river basins. It is done as situation warrants (e.g. during inclement weather affecting the river basins in the particular region) . Normally it is issued at 9:00 in the morning or 6:00 in the afternoon.
Contents:
a. Present weather situation – describes the current weather system affecting the country based on the weather advisory issued by the weather forecasting section
b. Forecast 24-hour rainfall - gives the forecast rainfall for the next 24 hours based on all available models (e.g. Light, moderate, heavy)
c. List of watercourses that are likely to be affected – gives the list of all the tributaries that will be affected given the forecast rainfall in the particular region.
d. Public warning – describes the suggested actions as to what the people and (local) disaster risk reduction and management council would do.
Preparation of Flood Forecast
The preparation, issuance and dissemination of an adequate and timely warning is the ultimate purpose of flood forecasting. Timeliness is an essential requirement for a flood warning. A sufficient lead time enables the ultimate user to take the necessary precautionary countermeasures.
The hydrological and meteorological conditions in a river basin and the consequent state of its river system is never constant. The behavior of the river itself is the resultant of the interaction of all hydrological processes and conditions in the river basin.
A flooding situation is not a daily occurrence. However, flood forecasting operations must, of necessity, be a continuous activity. It is carried out from day to day even when the possibility of a flood is highly improbable. This mode of operation enables flood forecasters to pinpoint the beginning of a potential flood-generating situation.
Like storm bulletins which are issued only during the presence of tropical cyclones, flood forecast and warning bulletins are prepared only when a potential flooding situation is definitely present. They are issued regularly at specified hours of the day for the duration of the flooding period until the flood recedes or when all hazards and dangers associated with the phenomenon are no longer present.
The prevailing hydrometeorological situation in a given river basin defines the operational environment under which flood forecasting and warning operations are carried out. Conveniently categorized into
- normal situation,
- alert phase, and
- warning phase
In practice1 flood bulletins are issued as soon as the development of a flooding situation exists. The initial bulletin serves merely to alert the people in the threatened basin to the possibility of a flood. It is never intended to categorically state that there will be flooding but only of the possibility. The initial bulletin is issued as soon as the operational situation passes from the alert to the warning phase. The transition from one operatiohal status to another is based on pre-determined criteria.
Thus, flood forecasting operation needs to be a continuing activity to determine the point in time when the operational situation passes from one phase to another. A flood forecasting operation consists of the following:
Monitoring:
This requires the collection, at regular interval, of the real-time data on rainfall, water level and other information that affect the hydrological condition of the river basin and the state of the river system. This provides a broad picture of the current situation in a river basin.
Analysis:
The data are analysed and related to other available information such as storm data from radar and satellite observation. The general objective here is to deduce the probable development in the hydrological situation in the river basin in the near future. This part of the operation involves a variety of hydrological analyses as well as the use of flood forecasting models to provide an objective estimate of the forecast situation.
Preparation of the forecast and warning:
Flood forecasts are completed in time for release at regular preset time of issuance. Dissemination is made through disseminating agencies such as the OCD1 DSWD, NDCC, and thru the mass media, particularly radio and television.
There are three categories of flood information intended for the general public. All are issued under the general title of "Flood Bulletin". A distinct series of bulletins is issued for each threatened river basin where the forecasting and warning service is already extended and operational. As already stated, bulletins are issued only when conditions,
i.e., there is a potential flooding situation, so warrant their issuance.
When required, flood bulletins are prepared twice daily. They are completed and readied for issuance and dissemination at 5 a.rn. and 5 p.rn., respectively, when it is deemed early enough to provide vital information for concerned users to take necessary countermeasures before they leave for work in the morning or before they retire at night.
A series of bulletins for a given affected river basin is ideally initiated by a Flood Outlook. As the category implies, the bulletin merely states the present hydrological situation and alerts the people in a basin to the possibility of a deteriorating condition, e.g., a gradual and continuous rise in the water level.
Subsequent bulletins could be of any one of the three categories. Normally, for a given affected basin, one bulletin is followed by another of the same in the next higher category depending on the development in the hydrological condition and the forecast situation. Hence, an Outlook is followed by another Outlook or by a Flood Advisory; or by a Flood Warning.
When the situation had clearly reached its worst such that, at most the condition or, at best, improvement can be expected, subsequent bulletins are of the same or by a next lower category than the proceeding.
Upon receipt of the coded messages, they are decoded and each set of observations is plotted in symbols or numbers on weather charts over the respective areas or regions. Observations made over land and sea are plotted on the surface or mean sea level charts which are prepared four times a day. Radiosonde, theodolite, aircraft and satellite wind observations are plotted on upper level charts which are prepared twice daily.
Flood bulletins are specifically directed to the public. They are intended to apprise the people in the threatened area of the present situation and of the expected development. It suggests the appropriate actions the community may have to take to prevent or mitigate the disastrous effects of a flood.
As in any kind of disaster, the best countermeasures for flood damage prevention and mitigation are those which are community efforts.
Floods cannot be prevented. To a large extent, however, they can be controlled effectively. By this is meant keeping the river from overflowing. There are a number of ways of accomplishing this before and during a flood:
- increasing the flow capacity of a river by cleaning the channel of debris, by dredging, by straightening of channels, etc.;
- construction of dikes and levees; and
- sandbagging during floods.
Individually and collectively, people in a flood-stricken area must take precautionary measures to ensure personnel safety and health:
- People, particularly children, should avoid wading in floodwaters.
- Where houses are expected to be flooded, people should move to higher places.
- Electrically operated appliances should be transferred to upper storeys of buildings.
- When electrical fines and outlets will be submerged in floodwater, power should be switched off.
Flood Safety Rules
BEFORE THE FLOOD:
- Find out how often your location is likely to be flooded.
- Know the flood warning system in your community and be sure your family knows it.
- Keep informed of daily weather condition.
- Designate an evacuation area for the family and livestock.
- Assign family members instructions and responsibilities according to an evacuation plan.
- Keep a stock of food which requires little cooking and refrigeration; electric power may be interrupted.
- Keep a transistorized radio and flashlight with spare batteries, emergency cooking equipment, candies, matches and first aid kit handy in case of emergency.
- Store supplies and other household effects above expected flood water level.
- Securely anchor weak dwellings and items.
- Watch for rapidly rising flood waters.
- Listen to your radio for emergency instructions.
- If you find it necessary to evacuate, move to a safe area before access is cut off by flood waters.
- Store drinking water in containers, water service may be interrupted.
- Move household belongings to upper levels.
- Get livestock to higher ground.
- Turn off electricity at the main switch in the building before evacuating and also lock your house.
- Avoid areas subject to sudden flooding.
- Do not attempt to cross rivers of flowing streams where water is above the knee.
- Beware of water-covered roads and bridges.
- Avoid unnecessary exposure to the elements.
- Do not go swimming or boating in swollen rivers.
- Eat only well-cooked food. Protect leftovers against contamination.
- Drink clean or preferably boiled water ONLY.
- Re-enter the dwellings with caution using flashlights, not lanterns or torchers. Flammables may be inside.
- Be alert for fire hazards like broken wires.
- Do not eat food and drink water until they have been checked for flood water contamination.
- Report broken utility lines (electricity, water, gas and telephone) to appropriate agencies authorities.
- Do not turn on the main switch or use appliances and other equipment until they have been checked by a competent electrician.
- Consult health authorities for immunization requirements.
- Do not go in disaster areas. Your presence might hamper rescue and other emergency operations
THINGS ONE CAN DO TO MITIGATE FLOODS:
- Regulate cutting of trees.
- Report illegal loggers and kaingeros.
- Report illegal construction of fishponds and other establishments in waterways.
- Do not throw garbage in esteros and rivers.
- Help clean the neighborhood.
- Support community activities intended to lessen the occurrence of floods.
- Avoid throwing anything like plastic wrappers anywhere which may clog or block the drainage system.
AGNO RIVER BASIN
ISSUED AT 25 JULY 2018
VALID UNTIL TOMORROW 9AM
OBSERVED RAINFALL: LIGHT RAINS WAS OBSERVED OVER THE BASIN DURING THE PAST 24 HOURS.
FORECAST RAINFALL: LIGHT RAINS
OBSERVED WATER LEVEL: WATER LEVEL WITHIN THE BASIN IS EXPECTED TO REMAIN NORMAL DURING THE FORECAST PERIOD.
DUTY HYDROLOGISTS: NCN
Updated: 27 August 2018
{/source}
General Flood Advisory issued as of 7 PM, 20 August 2018
