PurposePurpose

Increase the participants Increase the participants knowledge and understanding of knowledge and understanding of the interaction between the interaction between meteorology and hydrology in meteorology and hydrology in watersheds:watersheds:

Increase participants Increase participants understanding of the functional understanding of the functional aspects of watersheds;aspects of watersheds;

Enhance the participants Enhance the participants knowledge of the capabilities, knowledge of the capabilities, limitations, and applications of limitations, and applications of hydrologic/hydrometeorologic hydrologic/hydrometeorologic forecasting systemsforecasting systems

In the end, it is intended that In the end, it is intended that participants will understand participants will understand the basics of the hydrologic the basics of the hydrologic

forecast process, the forecast process, the assumptions in the process, assumptions in the process,

and the responsibilities and the responsibilities associated with interpreting associated with interpreting

and issuing the forecast.and issuing the forecast.

HydrologyHydrology

• … an earth science. It encompasses the occurrence, distribution, movement, and properties of the waters of the earth and their environmental relationships." (Viessman, Knapp, Lewis, & Harbaugh, 1977 - Introduction to Hydrology, Harper & Row Publishers, New York)

History of HydrologyHistory of Hydrology

Early philosophers speculated on the Early philosophers speculated on the hydrologic cycle:hydrologic cycle:

Homer believed that there existed Homer believed that there existed large subterranean reservoirs that large subterranean reservoirs that fed the rivers, seas, springs, and fed the rivers, seas, springs, and wells - wells - was he wrong?was he wrong?

Homer did understand the Homer did understand the dependence of flow in the Greek dependence of flow in the Greek aqueducts on conveyance and aqueducts on conveyance and velocity!velocity!

History, cont....History, cont....

In the first century B.C., Marcus Vitruvius In the first century B.C., Marcus Vitruvius in the treatise De Architectura Libri in the treatise De Architectura Libri Decem (the engineers chief handbook), Decem (the engineers chief handbook), Vol. 8 Vol. 8 hypothesizedhypothesized that rain and snow that rain and snow falling in the mountains infiltrated into falling in the mountains infiltrated into the earth’s surface and appeared in the the earth’s surface and appeared in the lowlands as springs and streams.....lowlands as springs and streams.....

Early Success.....Early Success.....

4000 B.C. The Egyptians built a dam on 4000 B.C. The Egyptians built a dam on the Nile to allow barren lands to again be the Nile to allow barren lands to again be used for agricultural purposes.used for agricultural purposes.

1000’s of years later, a canal to carry 1000’s of years later, a canal to carry fresh water from Cairo to Suez was built.fresh water from Cairo to Suez was built.

Towns in Mesopotamia were protected by Towns in Mesopotamia were protected by flooding from high earthen walls.flooding from high earthen walls.

Early Disputes and RulesEarly Disputes and Rules The cities of Lagash and Umma of Mesopotamia The cities of Lagash and Umma of Mesopotamia

have documented water disputes.have documented water disputes. The Romans decree:The Romans decree: Ne quis aquam oletato dolo malo ubi publice Ne quis aquam oletato dolo malo ubi publice

saliet si quis oletarit sestertiorum X mila multa saliet si quis oletarit sestertiorum X mila multa estoesto

It is forbidden to pollute the public water supply; It is forbidden to pollute the public water supply; any deliberate offender shall be punished by a any deliberate offender shall be punished by a fine of 10,000 sesterces!fine of 10,000 sesterces!

Qualitative Qualitative UnderstandingUnderstanding

Near end of 15th century, Leonardo da Near end of 15th century, Leonardo da Vinci and Bernard Palissy independently Vinci and Bernard Palissy independently reached conclusions on the hydrologic reached conclusions on the hydrologic cycle - based on a philosophical cycle - based on a philosophical understanding.understanding.

There was still a lack of There was still a lack of quantitativequantitative understanding of the hydrologic cycle.understanding of the hydrologic cycle.

The 17th CenturyThe 17th Century Perrault, Mariotte, and Halley began quantitative Perrault, Mariotte, and Halley began quantitative

measurements and applicationsmeasurements and applications Perrault measured rainfall and runoff over the Seine River Perrault measured rainfall and runoff over the Seine River

drainage basin for ~ 3 years - he illustrated that rainfall drainage basin for ~ 3 years - he illustrated that rainfall WAS adequate in quantity to account for river flowsWAS adequate in quantity to account for river flows

Mariotte gauged the velocity of the flow in the River Seine Mariotte gauged the velocity of the flow in the River Seine and estimated flows by also estimating river cross and estimated flows by also estimating river cross sectional areas.sectional areas.

Halley was an astronomer! He estimated evaporation from Halley was an astronomer! He estimated evaporation from the Mediterranean Sea and correlated it to river flows into the Mediterranean Sea and correlated it to river flows into the Med, concluding that river flows were sufficient the Med, concluding that river flows were sufficient enough to provide that volume of water.enough to provide that volume of water.

The 18th CenturyThe 18th Century

Bernoulli - famous for hydraulics and fluid Bernoulli - famous for hydraulics and fluid mechanics - the piezometer, the pitot mechanics - the piezometer, the pitot tube, and Bernoulli’s theorem.tube, and Bernoulli’s theorem.

The Chezy formula (channel flow)The Chezy formula (channel flow)

The 19th CenturyThe 19th Century

Hagen-Poiseuille - capillary flow equation.Hagen-Poiseuille - capillary flow equation. Darcy’s - flow in porous media.Darcy’s - flow in porous media. Duptuit-Thien well formula.Duptuit-Thien well formula. Manning - Open channel flow.Manning - Open channel flow. Systematic stream gaging.Systematic stream gaging. Mostly empirical in nature.Mostly empirical in nature.

The 20th CenturyThe 20th Century

Government agencies began to develop Government agencies began to develop programs!programs!

Rational analysis beginsRational analysis begins Sherman - Unit hydrograph theorySherman - Unit hydrograph theory Horton - infiltration theoryHorton - infiltration theory Snyder - Unit HydrographSnyder - Unit Hydrograph Clark - Unit HydrographClark - Unit Hydrograph etc...........etc...........

Relatively Speaking….Relatively Speaking….

HydrologyHydrology HydrometeorologyHydrometeorology Forecasting…….Forecasting…….

still relatively young!still relatively young!

Modern dayModern day

Very computer and data intensiveVery computer and data intensive High tech instrumentsHigh tech instruments Scale issuesScale issues Policy issuesPolicy issues Decision SupportDecision Support Forecasting!Forecasting!

Reasons to ForecastReasons to Forecast

Drought PredictionsDrought Predictions AgricultureAgriculture FloodingFlooding WarningsWarnings Decision MakingDecision Making

HydrometeorologyHydrometeorology

•… an interdisciplinary science involving the study and analysis of the interrelationships between the atmospheric and land phases of water as it moves through the hydrologic cycle." (Hydrometeorological Service Operations for the 1990's, Office of Hydrology, National Weather Service, NOAA, 1996).

HydrometeorologyHydrometeorologySimplification of the LinksSimplification of the Links

HydrologyEngineering/Fluid

Mechanics

In-depth hydrologicanalysis

Execution of complexhydrologic models.Adjustment ofmodel parameters, andthe derivation ofhydrologic forecasts forall time scales

Applied hydrologicresearch

Development andcalibration ofhydrologic models

Development ofhydrologic applicationsprocedures.

MeteorologyThermodynamics/atmospheric

physics orientation

In-depth meteorologicalanalysis

Weather forecast andwarning operations

Climatological forecasting Applied meteorological

and climatologicalresearch.

Development and calibrationof meteorological models

Development ofmeteorological applicationsand procedures.

HydrometeorologyInterdisciplinary

Orientation

Assimilation/use ofradar basedprecip. estimates

Production and/oruse of QPF's andother hydromet.forecasts

Use of guidance(e.g. flash flood) inhydrologic warningoperations

Use of soil moisturestates fromhydrologic model inatmospheric model

Appliedhydrometeorologicalresearch.