LESSON 3 Flashcards
About ________ of the total precipitation that falls on continental areas is turned to the seas by direct _______________
1/4 ; runoff and underground
The Philippines receives an average of __________ mm of rainfall every year. However, the amount is not __________ distributed over time and space
2,360 mm or 2.360 m ; evenly
The rainfall patter in the Philippines is affected by the major streams by the movement of the ___________ and by the ________________
ITCZ and cyclonic disturbance
The Philippines has a mean annual number of about ______ rainy day
175
What are the 3 requirements for precipitation to occur
- Cooling of the air mas sufficient to bring it to or near saturation
- Presence of condensation or freezing nuclei
- Growth of water droplets
Any product of condensation of atmospheric water vapor in the free air or at the earth’s surface
Hydrometeor
Types of Hydrometeor
Drizzle or mist
Rain
Glaze
Rime
Snow
Hail
Sleet
Consist of liquid water drops mostly larger than 0.5 mm in diameter
Rain
Consist of tiny liquid water droplets
Drizzle or Mist
Ice coating on exposed surface by the freezing of supercooled water ; transparent
Glaze
White, opaque deposit of ice granuled
Rime
Composed of ice crystals ; snowflakes
Snow
Precipitation in the form of balls of ice
Hail
Consist of transparent, globular, solid grains of ice formed by the freezing of rain drops.
Sleet
TYPES OF PRECIPITATION ACCORDING TO LIFTING MECHANISM
Convective
Orographic
Frontal
Cyclonic
It is caused by unequal heating of land masses
Convective
Mechanical lifting over mountain barriers
Orographic
Lifting of warm air on one side of a frontal surface over colder, denser air on the other side (front-bounding surface between two distinct air masses)
Frontal
Lifting of air converging into a low pressure area
Cyclonic
Rainfall Characteristics
Intensity
Duration
Frequency
Expressed in mm/hr
Intensity
Return period or recurrence interval; Period within which magnitude of a hydrological event will be equaled or exceeded once in the average
Frequency
TRUE OR FALSE
Correct interpretation of precipitation data is important to avoid miscalculated conclusions
False, Erroneous conclusions
The quality of precipitation data is affected by change in:
gage location
gage exposure
instrumentation
observational procedure
