This was put together by Rick Allen, of the University of Idaho at the Kimberly Research and Extension Center on Jan 22, 1999, for a hydrology class.
For a more detailed explanation of ET, including a program, please check this web site
There is not a single fantastic ET source page on the web that I know of. Several states have ET data posted. A few universities have the ET algorithms for their models posted. I'll list below the places that I know of.
You know, a great "source" of information on computing ET for both hydrologic and agricultural applications would the Chapter 4 "Evaporation and Transpiration" of the ASCE Hydrology Handbook, published in 1996. Bill Pruitt and I were the main writers on this chapter. It covers application of the Penman-Monteith equation to a wide variety of surfaces and discusses energy balance and evaporation prediction as well.
The chapter is a little long, but I would have no reservations concerning your photocopying the chapter for classroom and student use (I wouldn't think that ASCE would mind either). Someone on campus should have a copy of the handbook. I think that it is a great summary of current approaches.
--------
on the WWW:
Pan evaporation, data sources and current studies by NOAA:
http://www.ncdc.noaa.gov/ogp/papers/peterso2.html
ET for S. Idaho and irrigated areas of the NW:
http://mac1.pn.usbr.gov/agrimet/
and specifically:
http://mac1.pn.usbr.gov/agrimet/etsummary.html
---
Models that "do" ET:
SWAT Model (contains EPIC):
http://www.brc.tamus.edu/swat/
specifically, hydrologic components of SWAT, including surface
runoff and ET, are summarized at:
http://www.brc.tamus.edu/swat/usermanual/modelcomponents.html
Evapotranspiration equations in SWAT are given at:
http://www.brc.tamus.edu/swat/usermanual/evapotranspiration.html
I don't care much for the specific approach that they use and how
they estimate certain parameters. However, I agree with their overall
approach and equations used.
Weather data generation is described at:
http://www.brc.tamus.edu/swat/usermanual/weather.html
---
There is a USDA-ARS model called OPUS that can be downloaded
at:
ftp://129.82.171.11/pub/roger/opus/
This model is purported (by the author) to be the best thing since
sliced bread. It models transport of chemicals in the unsaturated
zone, but also has a detailed evaporation/transpiration component.
---
Dr. Gerald Flerchinger of the USDA-ARS in Boise has a very nice
arid-lands ET/hydrology model (SHAW) that seems to work nicely for
him. The model even does snow melt:
http://ars-boi.ars.pn.usbr.gov/Models/SHAW.html
---
Then there is always the older, but always evolving SPAW model by
Saxton of ARS in Pullman (Myron, you for sure have this).
---
Some soil water content sensors for measuring ET:
A Huge source of web sites on remote sensing applications (some
for ET related information):
http://www.vtt.fi/aut/ava/rs/virtual/other.html#satdat
-----
Another climate generator (Tmax, Tmin, solar radiation, only) is by
Clayton Hansen of the USDA ARS in Boise:
http://ars-boi.ars.pn.usbr.gov/models/usclim.html
-------------
In addition, Myron, by various States, one can chase down some ET value information from the following summary that I happened to put together the other day (mostly for irrigation related ET (SORRY)). I'll attach this file, also in Word'97 entitled IA-ET.doc in case this is more useful. This list is mostly human contacts (Emails, etc.), but occaisionally a web address is given:
Listing of Potential Contacts for State ET information
Compiled by Rick Allen, Jan. 1999
Pacific Northwest
Agrimet: About 50 automated weather stations in Washington, Oregon,
Idaho, W.Montana, N. Calif (1), Wyoming (1). Data are available on 24-
hour summary or each 15 minutes. “Crops” include lawn.
Operator is the US Bureau of Reclamation. Home page for Agrimet is:
{ HYPERLINK http://mac1.pn.usbr.gov/agrimet/ }http://mac1.pn.usbr.gov/agrimet/
Map of Agrimet stations in Washington, Oregon, Idaho, W.Montana, N.
Calif (1), Wyoming (1) is at:
{ HYPERLINK http://mac1.pn.usbr.gov/agrimet/agrimetmap/agrimap.html }http://mac1.pn.usbr.gov/agrimet/agrimetmap/agrimap.html
Data Access is described at:
{ HYPERLINK http://mac1.pn.usbr.gov/agrimet/webarcread.html }http://mac1.pn.usbr.gov/agrimet/webarcread.html?
Utah
Dr. Bob Hill, Utah State University, Biological and Irrigation Engineering,
Logan, UT 435-797-2791, { HYPERLINK mailto:BobH@ext.usu.edu }BobH@ext.usu.edu
Bob has issued an irrigation water requirement bulletin for the state of
Utah that is based on the SCS Blaney-Criddle equation calibrated against
the 1982 Kimberly Penman (alfalfa reference) equation throughout the state.
Dr. Don Jensen, Utah State Climatologist, Utah Climate Center, Utah State
University, Logan, UT.
Utah Climate Center: http://climate.usu.edu/
4825 University Blvd, Logan, Utah 84322-4825, Telephone: 435-797-2190,
Fax: 435-797-2117
Don has published an irrigation water requirement report for the state of
Utah that is based on the 1985 Hargreaves grass reference equation.
The UCC site also provides access to temperature and precipitation data
for the entire globe, for free. The data base includes all 50 states.
Idaho
Dr. Richard G. Allen, University of Idaho Research and Extension Center,
Kimberly, Idaho 83341 208 423 6601 published an irrigation water
requirements report for the state of Idaho in 1983 (Allen, R.G. and C. E.
Brockway. 1983. Estimating Consumptive Irrigation Requirements for
Crops in Idaho, Research Technical Completion Report, Idaho Water and
Energy Resources Research Institute, University Idaho, Moscow, ID 130
pages.) The 1983 report was based on the FAO-Blaney-Criddle equation
that was calibrated against the 1982 Kimberly Penman (alfalfa reference)
equation. Crop coefficients were those of Wright (1982). The 1983 report
is being updated.
{ HYPERLINK mailto:RAllen@Kimberly.UIdaho.edu }RAllen@Kimberly.UIdaho.edu
Idaho is part of the Agrimet system (see above).
Oregon
Dr. Richard Cuenca, Dept. Bioresources Engineering, Oregon State
University, has published a state-wide report on irrigation water
requirements for Oregon. This report was based on the FAO-Blaney-
Criddle equation. { HYPERLINK mailto:Cuenca@engr.orst.edu }Cuenca@engr.orst.edu
Mario Hess, Jason Smesrud, and John Selker of the Department of
Bioresource Engineering at Oregon State University have an on line
Irrigation Guide for Western Oregon at:
{ HYPERLINK http://biosys.bre.orst.edu/bre/docs/IrrigationGuide.html }http://biosys.bre.orst.edu/bre/docs/IrrigationGuide.html
John Selker can be found at 116 Gilmore Hall, Corvallis, OR 97331-3906,
(541) 737-6304
{ HYPERLINK mailto:selkerj@ccmail.orst.edu }selkerj@ccmail.orst.edu
Oregon is also part of the Agrimet system described above.
Washington
Washington is part of the Agrimet system and operates the PAWS
agrimeteorological system as well.
PAWS = Public Agricultural Weather System. It is compsed of 58 real-time
ag. Met stations ansd is located at:
{ HYPERLINK http://frost.prosser.wsu.edu/ }http://frost.prosser.wsu.edu/
A location map for Washington sites is at
{ HYPERLINK http://frost.prosser.wsu.edu/images/locations/pawsmap.gif }http://frost.prosser.wsu.edu/images/locations/pawsmap.gif
Developed by Dr. Tom Ley (former with WSU), PAWS is now directed by
Dr. Mary J. Hattendorf - AG Meteoroligist/PAWS System Coordinator.
{ HYPERLINK mailto:wsupaws@president.prosser.wsu.edu }wsupaws@president.prosser.wsu.edu
WSU PAWS, 24106 N. Bunn Rd., Prosser, WA 99350, VOICE: (509)-786-
9219 FAX: (509)-786-9370
PAWS weather data are available in 15 minute, hourly and 24-hour
summaries. ET is available as alfalfa or grass reference in 24-hour
summaries.
Wyoming
I believe that the most recent irrigation water requirements report for
Wyoming was in the form of a thesis by Travis Teegarten in about 1993.
Travis worked with Dr. Larry Pochop, Professor of Civil Engineering
Room 2098, Engineering Building, University of Wyoming, College of
Engineering, Box 3295,
Laramie, WY 82071-3295, e-mail: pochop@uwyo.edu , Office Phone : (307)
766-3326, Fax Number: (307) 766-4444
Teegarten used the “FAO Penman-Monteith” equation, which is the ASCE
Manual 70 Penman-Monteith equation applied to a 0.12 m tall clipped
grass.
Arizona
I believe that you have Dr. Paul Brown, already, who is the best contact
California
The California Dept. Water Resources operates the CIMIS system that
reports ETo for a large number of stations around the state on an hourly,
real-time basis. The ETo is computed by the hourly CIMIS equation, which
is grass based.
The CIMIS home pages is at:
{ HYPERLINK http://wwwdpla.water.ca.gov/cgi-bin/cimis/cimis/hq/main.pl }http://wwwdpla.water.ca.gov/cgi-bin/cimis/cimis/hq/main.pl
A summary of CIMIS is available at:
{ HYPERLINK http://wwwdpla.water.ca.gov/nd/LandWaterUse/cimisintro.html }http://wwwdpla.water.ca.gov/nd/LandWaterUse/cimisintro.html
For additional information on CIMIS reference ETo calculation or ETo
equation, contact:
1.Richard Snyder
Biometeorologist
University of California, Davis
Department of Land, Air and Water Resources
Davis, CA 95616-8627
rlsnyder@ucdavis.edu
2.Baryohay Davidoff, Chief Agricultural Water Conservation Section
California Department of Water Resources
1020 9th Street
Sacramento, CA 95814
baryohay@water.ca.gov
3.Simon Eching
California Department of Water Resources
seching@water.ca.gov
New Mexico
Dr. Ted Sammis, Professor of Agronomy and Horticulture, MSC 3Q, New
Mexico State University, Las Cruces, NM, tele 646-2104 ,
{ HYPERLINK mailto:tsammis@nmsu.edu }tsammis@nmsu.edu
Ted has done various ET measurement work in New Mexico over the years
and probably knows where to go for ET information.
Texas
The Texas North Plains PET Network , The Official Potential
EvapoTranspiration Website of the Texas North Plains is Designed and
Constructed by Thomas and Gary Marek, T.A.E.S. and A.R.S at
{ HYPERLINK http://amarillo2.tamu.edu/nppet/petnet1.htm }http://amarillo2.tamu.edu/nppet/petnet1.htm
The network uses a modified Penman-Monteith equation for calculating
ETo. The PET system has a network of 10 weather stations located
throughout the The North Plains whereby PET calculations are made and
disseminated in an automated process providing timely, accurate, predicted
evapotranspiration data.
Dr. Terry Howell ({ HYPERLINK mailto:tahowell@ag.gov }tahowell@ag.gov) of ARS in Bushland has a
presentation comparing the ASCE Penman-Monteith for alfalfa reference to
lysimeter measurements at Bushland:
{ HYPERLINK http://www.cprl.ars.usda.gov/wmru/howell/Tipton/ }http://www.cprl.ars.usda.gov/wmru/howell/Tipton/
Other information on the PET site is at:
{ HYPERLINK http://www.cprl.ars.usda.gov/petweb.htm }http://www.cprl.ars.usda.gov/petweb.htm
Dr. Guy Fipps, Texas A&M has worked with Dr. Terry Howell, USDA-ARS
in Bushland. Guy has created a “crop coefficient” page for turf and crops
in Texas at:
{ HYPERLINK http://www.agen.tamu.edu/wqit/petnet/tools/coe-tool.html }http://www.agen.tamu.edu/wqit/petnet/tools/coe-tool.html
Colorado
Mark Crookston at the Northern Colorado Conservancy District
{ HYPERLINK mailto:mcrookston@ncwcd.org }mcrookston@ncwcd.org
And Brent Mecham { HYPERLINK mailto:bmecham@ncwcd.org }bmecham@ncwcd.org
Have weather stations for the NE part of the state.
CSU, via Dr. _______ Garcia, has been developing a GIS type of water
resources management system for the state of Colorado that includes ET
information. Brent may be aware of the details and source.
Nebraska, Kansas
Ken Hubbard of the Nebraska High Plains Climate Center:
{ HYPERLINK http://hpccsun.unl.edu/ }http://hpccsun.unl.edu/
Keeps Ag. Met data for Nebraska, Kansas and parts of Colorado,
Wyoming, S. Dakota and N. Dakota. They routinely compute reference ET.
Oklahoma
Dr. Ron Elliot of Oklahoma State University: { HYPERLINK mailto:relliot@agen.okstate.edu }relliot@agen.okstate.edu
Is involved with the Oklahoma Meso Weather network. They have about
100 electronic weather stations scattered around Oklahoma. They make
routine estimates of ETo.
Iowa
You may try to contact Dr. Robert Horton of the Dept. Agronomy, Iowa
State University: { HYPERLINK mailto:rhorton@iastate.edu }rhorton@iastate.edu
Bob is in the soils area, but is an “ET” kind of guy.
The climatology section of the Agronomy Dept. is chaired by Dr. Richard
Carlson: { HYPERLINK mailto:richard@iastate.edu }richard@iastate.edu
Dr. Carlson is a professor of Ag. Meteorology.
Another contact for Iowa is Dr. Jerry Hatfield, Director of the USDA
National Soil Tilth Lab at Ames: { HYPERLINK mailto:hatfield@iastate.edu }hatfield@iastate.edu
Jerry has been making a number of ET measurements in Iowa and other
places using eddy correlation and Bowen ratio
Minnesota
The Department of Soil, Water and Climate at the Univ. Minnesota:
{ HYPERLINK http://www.soils.agri.umn.edu/links/ }http://www.soils.agri.umn.edu/links/
Has climate information at
{ HYPERLINK http://www.soils.agri.umn.edu/research/climatology/ }http://www.soils.agri.umn.edu/research/climatology/
Jerry Wright West Central Experiment Station, Morris, Minnesota (320) 589-
1711 { HYPERLINK mailto:jwright1@extension.umn.edu }jwright1@extension.umn.edu
and
Mark Seeley Dept. of Soil, Water, and Climate, Univ. of Minnesota (617)
625-4724 { HYPERLINK mailto:mseeley@soils.umn.edu }mseeley@soils.umn.edu
Are probably the best contacts.
Wisconsin
The Univ. Wisconsin keeps various ag. Weather data and ET maps for
various states (during summer) at:
{ HYPERLINK http://bob.soils.wisc.edu/wimnext/sunwater.html }http://bob.soils.wisc.edu/wimnext/sunwater.html
Bill Bland Dept. of Soil Science, Univ. of Wisconsin-Madison
{ HYPERLINK mailto:wlbland@facstaff.wisc.edu }wlbland@facstaff.wisc.edu is probably the best contact.
Ohio
I’ve obtained weather data in the past for the Ohio Ag. Weather network
from Dr. J.R. Holman of the Ohio Agric. Res. And Dev. Ctr., Ohio State
University at Wooster.
Also, the USDA-ARS station at Coshocton, Ohio has been operating
weighing lysimeters for many years on natural grass vegetation. They can
be contacted via the USDA web pages.
North Carolina
Dr. D. C. Sanders, Extension Horticultural Specialist, Department of
Horticultural Science, North Carolina Cooperative
Extension Service, North Carolina State University, has information on
vegetable crop irrigation for North Carolina at:
{ HYPERLINK http://www.ces.ncsu.edu/depts/hort/hil/hil-33-e.html }http://www.ces.ncsu.edu/depts/hort/hil/hil-33-e.html
South Carolina
Dr. Carl Camp of the USDA-AR Coastal Plains Research Center, Florence
SC: { HYPERLINK mailto:Camp@florence.ars.usda.gov }Camp@florence.ars.usda.gov
may be a source of data for S. Carolina. Carl was a coeditor of the
Proceedings of the ASAE Conference on Evapotranspiration and Irrigation
Scheduling, San Antonio, Texas in 1996.
Georgia
I don’t know many people in George, but Dr. Jean Steiner is a research
leader or director at one of the USDA-ARS centers in George. Jean
published extensively on ET during her time at Bushland, Texas.
Florida
Dr. Brian Boman of the Univ. Florida Research Center at Ft. Pierce, Florida would be a good contact for Florida. Brian works with ET from Citrus, but serves on ASAE and ASCE ET committees and he knows Florida. { HYPERLINK "mailto:BJBO@gnv.ifas.ufl.edu" }BJBO@gnv.ifas.ufl.edu
The University of Florida at Gainesville keeps an archive of Ag. Weather data. My experience in using these data have been that they need substantial filtering and other assessment.
Dr. L.H. Allen with the USDA-ARS at Gainesville also does research in ET in Florida and would be a good contact.
--------------------
> Rick,
> I heard by the grapvine that you knew something about ET. That being the
> case, you are sure to know enough to help me in the hydrology class.
>
> I am looking for evaporation or ET links for the class home page. Do you
> have any good places where I can point the students for more info than what
> I give them in class (which is minimal, at best). I have no links
> specifically on ET or evaporation but there must be some out there.
>
> Hope you are enjoying the reintroduction to Idaho. So far it's been a good
> winter and it looks like the water supply is building up very nicely.
>
> Take care and thanks in advance.
>
> Myron
>
> Hydrology page
>
> http://snow.ag.uidaho.edu/classes/hydrology
> or
> http://snow.ag.uidaho.edu
>
> /\ /\
> /\ / \ / \ /\
> /\/\/\/\/\/ \/\/ \/\/ \/\/ \/\/\/\/\/\/\/\/\/\/\/\/\++
> Myron Molnau 208-885-6184 climate@uidaho.edu
> Climate Lab 208-885-7004
> State Climate Services http://www.uidaho.edu/~climate
> Biological & Agricultural Engineering Dept 208-885-7908 fax
> 425 Engineering/Physics Bldg
> University of Idaho
> Moscow,Idaho 83844-0904
> ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
>
=================================================
Dr. Richard G. Allen
Professor of Water Resources Engineering
Dept. Biological and Agricultural Engineering
Dept. Civil Engineering
University of Idaho Research and Extension Center
3793 N. 3600 E.
Kimberly, Idaho 83341
Tel (208)423-6601
Fax (208) 423-6559
RALLEN@Kimberly.UIdaho.edu
=================================================