Hydrology

Earth2Class Workshops for

Teachers Lamont-Doherty Earth

Observatory



―Hydrology‖

Dr. Michael J. Passow

Guest Scientist: Dr. Upmanu Lall

May 11, 2002

Hydrology involves the study of

water as it moves through the

• Atmospheric system

• Oceanic system

• Freshwater system

• Groundwater system

• Cryosphere (―frozen system‖)

We often summarize the complex

transfer of matter and energy as the

―Water Cycle‖









http://www.chias.org/www/edu/mitc/wkshp/ocean/oceans.html

For obvious reasons, we tend to focus

on the more visible aspects of the

Water Cycle

• Precipitation in all its

various forms: rain,

drizzle, thunderstorm,

mist, snow, blizzard,

etc.

• Also, flooding and

drought focus

attention on

hydrology



http://www.usatoday.com/weather/wtsm5.htm

Occasionally we think about other

aspects of the Water Cycle

• Influence on landscapes, such as stream-

cut canyons, waterfalls, and karst

topopgraphy

• Transpiration from plants

• Groundwater contaminants

• http://www.gsfc.nasa.gov/GSFC/EARTH/at

mos/ozone.htm

ENERGY TRANSFERS ALSO OCCUR WITHIN THE

WATER CYCLE

• EVAPORATION/CONDENSATION–

GL

LATENT HEAT OF VAPORIZATION



• MELTING/FREEZING–

SL

LATENT HEAT OF FUSION



• SUBLIMATION/DEPOSITION—

SG

American Meteorological

Society’s

―Water in the Earth Systems‖









http://www.ametsoc.org/amsedu/WES/home.html

Monitoring stream flow









• http://www.epa.gov/surf3/locate/

Flooding









• http://www.noaa.gov/

Drought









http://enso.unl.edu/monitor/monitor.html

Water quality issues

• www.water.usgs.gov









http://ga.water.usgs.gov/edu/pictureshtml/fishshock.html

Groundwater systems

http://www.groundwater.com/



http://www.groundwater.com/what_is_groundwater.html



http://water.usgs.gov/

Coastal issues

www.nos.noaa.gov









http://www.noaa.gov/coasts.html

Observations from space

• Water vapor images

from weather

satellites









http://www.goes.noaa.gov/

Tropical Rainfall Measuring

Mission (TRMM)

• http://trmm.gsfc.nasa.gov

NASA’S ―Earth Observatory‖







Internet-based images and articles by NASA

scientists intended for the general public

Focus on Earth and environmental change

Sections include: Data & Images, News, Features,

Missions, Experiments, and References

http://www.earthobservatory.nasa.gov/

Climate influences on the

Water Cycle

• El Nino, La Nina, NAO

and other climatic

influences on rainfall,

drought, etc.

• Cyclic, non-cyclic









http://www.noaa.gov/

Examples of Hydrology-Related

LDEO Research

• Hudson River Research

http://www.ldeo.columbia.edu/programs/in

dex.html

• IRI

http://iri.ldeo.columbia.edu/application/sec

tor/water/

Examples of Science Education

Standards

ILS 1.2g Earth has continuously been

recycling water since the outgassing of

water early in its history. This constant

recirculation of water at and near Earth's

surface is described as the hydrologic

(water) cycle.

• PS/ES 2.1u. The natural agents of erosion

include: Streams (running water): Gradient,

discharge, and channel shape influence a

stream's velocity and the erosion and

deposition of sediments. Sediments

transported by streams tend to become

rounded as a result of abrasion. Stream

features include V-shaped valleys, deltas,

flood plains, and meanders. A watershed is

the area drained by a stream and its

tributaries.

Today’s Guest Scientist

• Dr. Upmanu Lall

Senior Research Scientist, IRI

http://iri.ldeo.columbia.edu/

Principal areas of expertise: statistical and

numerical modeling of hydrologic

climatic systems and water resource

systems planning and management.