hydrologic cycle.ppt

Siklus HidrologiSiklus Hidrologi

HujanHujan

EvaporasiEvaporasi

InfiltrasiInfiltrasi

HidrometriHidrometri

HidrografHidrograf

Hidrograf SatuanHidrograf Satuan

Analisis FrekuensiAnalisis Frekuensi

Penelusuran Penelusuran banjirbanjir

HidrologiHidrologi

PustakaPustaka

Applied Hydrology Chow, et.al., 1988 Applied Hydrology Chow, et.al., 1988

Hidrologi: Teori, Masalah dan Hidrologi: Teori, Masalah dan Penyelesaian (Sri Harto Br., 2000)Penyelesaian (Sri Harto Br., 2000)

Handbook of Hydrology (Maidment, Handbook of Hydrology (Maidment, et al., 1993)et al., 1993)

Engineering Hydrology (Ponce, 1989)Engineering Hydrology (Ponce, 1989)

HEC-HMSHEC-HMS

BanjirBanjirBanjirBanjir

BanjirBanjir

KekeringanKekeringan

BanjirBanjirKebutuhan AirKebutuhan Air

0

10

20

30

40

50in

ten

sita

s h

uja

n (

mm

/jam

)

Jam

Σhujan = 90.48mmΣlimpasan langsung =

29.16mm

Transformasi hujan-aliranTransformasi hujan-aliran

URBANISASI

Pendudukmeningkat

Sarana/prasaranameningkat

Limbahmeningkat

Air baku/DMImeningkat

sistem drainasiberubah

Lap. kedap airmeningkat

MasalahSDA

MasalahSDA

Kualitas airmenurun

Pengisian air tanah menurun

Kecepatan aliranmeningkat

runoff volumemeningkat

Aliran dasarmenurun

Lag time, time base menurun

Debit puncakmeningkat

Masalahpengendalian polusi

Masalahpengendalian polusi

Masalahpengendalian banjir

Masalahpengendalian banjir

Siklus HidrologiSiklus Hidrologi

Hydrologic cycle/water cycle describes the existence and movement of water on, in, and above the Earth

The hydrologic cycle, or water cycle, is the cycling of water through the earth system.

Hydrologic cycle

The ocean as a storehouse of water

Distribution of Earth`s Water

Evaporation: The process by which water is changed from liquid to a gas or vapor

Studies have shown that the oceans, seas, lakes, and rivers provide nearly 90 percent of the moisture in our atmosphere via evaporation, with the remaining 10 percent being contributed by plant transpiration.

Evapotranspiration: The process by which water vapor is discharged to the atmosphere as a result of evaporation from the soil and transpiration by plants.

Transpiration: The release of water from plant leaves

Water storage in the atmosphere: Water stored in the atmosphere as vapor, such as clouds and humidity

Condensation: The process by which water is changed from vapor to liquid

Precipitation is water released from clouds in the form of rain, freezing rain, sleet, snow, or hail.. Most precipitation falls as rain.

Precipitation rates vary geographically and over time

Precipitation rates vary geographically and over time

Surface runoff: Precipitation runoff which travels over the soil surface to the nearest stream channel

Watersheds and rivers

A watershed (catchment area, river basin) is the area of land where all of the water that falls in it and drains off of it goes into the same place (control point at a river).

A catchment boundary can be determined through topography map.

Streamflow is always changing

Streamflow: The movement of water in a natural channel, such as a river

Ground-water discharge: The movement of water out of the ground

Spring: Place where a concentrated discharge of ground water flows at the ground surface

Infiltration: The downward movement of water from the land surface into soil or porous rock

Infiltration is controlled by soil texture, soil structure, vegetation and soil moisture status.

PrecipitationPrecipitation

Channel PrecipitationChannel PrecipitationInterceptionInterception

Depresion storageDepresion storage

Ground water flowGround water flow

InfiltrationInfiltration

InterflowInterflowSoil moistureSoil moisture

Ground waterGround water

Surface runoffSurface runoff

Channel

storage

Channel

storage

Streamflow

Streamflow

EvaporationEvaporationEvaporationEvaporation

Hydrologic cycle components

Transformasi hujan-aliran

HUJAN

Hujan efektif/ excess rainfall

Abstraksi/Loss

Aliran dasar

Hidrograf limpasan langsung

Hidrograf total

Transform method

The Water BalanceThe water balance is an accounting of the inputs and outputs of water.

The water balance of a place, whether it be an

agricultural field, watershed, or continent, can be

determined by calculating the input, output, and

storage changes of water at the Earth's surface.

Simple hydrologic system

I, Input (rainfall)

O, Output (runoff)

I - O = dS/dt

S inflow outflow

land

P E

ocean

SR

GWF

P E

P = rainfall E = evaporation GWF = ground water flow SR = surface runoff

Water balance at land:S = I - O

= P - (E + GWF + SR)P = E + GWF + SR + S

water balance at ocean: S = I - O

= (P + GWF + SR) - E P = E - GWF - SR + S

whereP = rainfallE = evaporationSR = surface runoff

GWF = ground water flow S = change of storage

Water balance at paddy field

http://www.ce.utexas.edu/prof/maidment

SaldoRp

Credit

Debit