that part of surface runoff that flows over the surfaces towards stream channel.

same as surface runoff.

same as interflow

same as groundwater runoff

groundwater discharge into a stream due to deep percolation of the infiltrated water into groundwater aquifers.

runoff due to the part of precipitation which infiltrates into the soil surface and moves laterally through the upper soil horizons towards streams as perched groundwater above the major groundwater level.

types of surface runoff

types of surface runoff

that part of runoff which travels over the ground surface and through the channels to reach the basin outlet.

normally applies to flow over a surface

describes the drainage after it reaches a defined channel

events under the same type of conditions or statistical properties are not changing

representative of long term of records for the region under analysis

a hydrologic event is not influenced by another event

a deterministic process is one in which a definite law of certainty exists

this means, the output is predictable for a given input

it is one where the chance element is ignored as in the case of flood routing

is one governed by chance phenomena, that is, there are so many causes at work that the influence of one cannot be readily identified

it is a time dependent. This means that the sequence of occurrence of events or the time series is considered in its analysis

is time series independent

any hydrologic phenomenon which undergoes continuous changes with time.

the probabilistic analysis of hydrologic processes

In very large watersheds it has prominent effects on runoff.

In smaller watershed it is the predominant factor affecting runoff.

is one which is very sensitive to high intensity rainfall of short duration with land area of less than 250 sq. km.

use of orifice, weir, flume and other control structure, staff gage, water level recorder

used to measure the stage or depth of flow above a datum or reference level.

the required time for a water particle to flow hydraulically from the most distant point in the watershed to the outlet.

magnitude of floods, design of structures such as drainage canals, flood spillways and culverts

flood warning time, watershed response, water quality

total water yield from a storm for a given watershed

time for surface flow and interflow to recede, duration of flooding

low flow, dependable flow, groundwater recharge

the pssage of water into the soil surface

the process by which precipitation reaching the earth's surface is returned to the atmosphere a vapor through 1. evaporation from wet surfaces and 2. transpiration by plants

the amount of water that could be evaporated and transpired if there were sufficient water available.

Distribution of Earth’s Water, Freshwater is

Saline (Oceans)

Groundwater

Icecaps and Glaciers

Rivers

Swamps

lakes

Freshwater other

A geologic formation or stratum containing water in its voids or pores that may be extracted economically and used as a source of water supply.

groundwater is confined under pressure greater than atmospheric by overlying impermeable strata. It is also known as artesian or pressure aquifer.

a water table serves as the upper surface of the zone of saturation. It is also known as a free, phreatic or non-artesian aquifer.

exists when the piezometric surface lies above the ground surface.

a geologic formation so impervious that for all practical purposes it completely obstructs the flow of groundwater (although it may itself be saturated with water).

A geologic formation of rather impervious and semi-confined nature which transmits water at a very slow rate compared to an aquifer.

movement of water through the phreatic zone

the ability of the soil to transmit water

velocity through the void spaces obtained by dividing the average velocity by the porosity

the science of water that is concerned with the origin, circulation, distribution and properties of water of the earth.

-basic unit of hydrology -area upstream of a point along a river where all water coming off mainly from precipitation drains towards that point.

Source of rain, Tropical cyclone

Source of rain, ITCZ and easterly waves

source of rain, SW AND NE

Tropical depression-max wind speed

Tropical storm -max wind speed

a westward-moving, wavelike disturbance of low atmospheric pressure embedded in tropical easterly winds. affects the country from April to May

Philippine land area

average rainfall

ph water resources- grounwater

ph water resources- surface water

ph water resources

rivers

lakes

that part of atmospheric moisture that falls on the earti surface.

fusion or coalescence of water droplets as a result of their coming in contact through the action on them of air movement and gravitational pull.

Ice crystals and water droplets are known to co-exist in the atmosphere at sub-freezing temperatures.This difference in pressure serves as the driving force for condensation of moisture over the crystals.