UP - CONCEPTS

also called throughflow

interflow

precipitation caught and held by vegetation or non-vegetated surfaces

interception

intercepted water that eventually dripped to the ground

throughfall

intercepted water that runs down plant stems

stemflow

radiation that is the primary source for Earth's climate and life processes

solar radiation

heat energy emitted by the earth back to the atmosphere and space

earth radiation

the average amount of solar energy reaching the outer atmosphere at mean Earth-sun distance

solar constant

small droplets collide and merge into larger droplets

coalescence

occurs in clouds where both supercooled water droplets and ice crystals exist together

Bergeron–Findeisen process

tiny solid particle help ice crystals form in clouds at temperature below freezing

sublimation nuclei

large balls of ice formed in thunderstorms with strong updrafts

hail

formed when supercooled water droplets freeze on contact with cold surfaces

rime

snow pellets are aka

graupel

frozen raindrops

sleet

rain that freezes and forms a smooth ice layer

glaze

air lifted by horizontal convergence of inflowing air into a low-pressure area

non-frontal cyclonic precipitation

warm air is forced to rise over colder and denser air along the boundary between air masses with different characteristics

frontal cyclonic precipitation

Tropical Depression Wind Speed

39-61 kph

Tropical Storm Wind Speed

62-88 kph

Severe Tropical Storm Wind Speed

89-117 kph

Typhoon Wind Speed

118-184 kph

Super Typhoon Wind Speed

185 kph or higher

Typhoon Wind Speed (2015)

118-220kph

Super Typhoon Wind Speed (2015)

more than 220 kph

Pag-asa rainfall advisory rainfall advisory is observed for ____ and expected to continue for ____

1 hr; 2 hrs

Yellow Rainfall Warning

7.5 to 15 mm

Orange Rainfall Warning

15 to 30 mm

Red Rainfall Warning

more than 30 mm

It is a computer aided method/GIS where the basin is divided into a grid network. The areal rainfall is obtained by getting the mean of all grid point values

Grid-Point Method

Used for non-uniform gauge distribution and rolling terrain; uses interpolation

Inverse distance Ratio Method

used when normal annual rainfall of the missing station differs significantly (>10%) from surrounding stations

Normal-ratio method

assumes rainfall at the missing station is the average of rainfall at the surrounding stations

arithmetic mean method

used for correcting inconsistent data

double mass analysis

Assumes hydrologic events are governed by physical laws that can be described exactly.

Deterministic Process

Does not involve randomness, which means that same inputs would always have the same output.

Deterministic Process

Recognizes that hydrologic events are influences by many factors and therefore contain randomness

Probabilistic Process

Uses probability theory to estimate the likelihood of events of a given magnitude

Probabilistic Process

A more advances approach where hydrologic data is modeled as a random process varying over time, often using statistics + time series.

Stochastic Process

Accounts for both randomness and temporal dependence

Stochastic Process

With distinct wet and dry seasons: wet during the months of May to October and dry during the months of November to April

Type 1

No dry season with a very pronounced maximum rainfall period from November to January

Type 2

Seasons not very pronounced: relatively dry during the months of November to April and wet during the rest of the year

Type 3

With more or less uniformly distributed rainfall throughout the year

Type 4

Davao Region, Cagayan Valley, Leyte

Type 4

Negros, Northern Mindanao, Cebu

Type 3

Batanes, Eastern Visayas (Samar), Bicol, CARAGA

Type 2

Central Luzon, Palawan, Ilocos

Type 1

The portion of runoff that flows over the ground surface and through drainage channels to reach the basin outlet; Occurs when rainfall intensity exceeds the soil's infiltration capacity.

Surface Runoff

The portion of precipitation that infiltrates the soil and moves laterally through the upper soil layers (perched groundwater) towards streams, occurring above the main groundwater table.

interflow

The runoff contributed by groundwater discharge into streams, resulting from the deep percolation of infiltrated water into aquifers.

Groundwater Runoff

Zone of aeration or the unsaturated zone

vadose zone

zone of saturation

phreatic zone

boundary between the zone of aeration (unsaturated zone) and the zone of saturation (phreatic zone) where the hydrostatic pressure is equal to the atmospheric pressure

water table

localized unconfined aquifer formed above an impermeable layer within the unsaturated zone

perched aquifer

bounded by semi-permeable layer above

leaky aquifer

calm waters

lentic

running waters

lotic

lake aging process

eutrophication

young lake; clear, nutrient poor; high oxygen

oligotrophic

middle-aged lake; nutrients and sediments accumulate gradually; moderate water quality

mesotrophic

old lake; high nutrients; becomes shallower

eutrophic

caused by temperature difference in lakes or reservoirs

stratification

top layer of lake

epilimnion

middle layer of lake

metalimnion

Bottom layer of the lake

hypolimnion

occurs when surface water cools, sinks, and displaces bottom water

turnover

peak photosynthesis

2:00 PM

max respiration

2:00 AM

refers to water clarity and is linked to total suspended solids

turbidity

minimum DO for aquatic life

3 mg/L