U.S. Geological Survey

Water-Resources Investigations Report

U.S. Department of the Interior

Comparison of Irrigation Water Use EstimatesCalculated From Remotely Sensed IrrigatedAcres and State Reported Irrigated Acres in theLake Altus Drainage Basin, Oklahoma and Texas,2000 Growing Season

03-4155

Prepared in cooperation with theBUREAU OF RECLAMATION

U.S. Geological Survey

Water-Resources Investigations Report

U.S. Department of the Interior

Comparison of Irrigation Water Use EstimatesCalculated From Remotely Sensed IrrigatedAcres and State Reported Irrigated Acres in theLake Altus Drainage Basin, Oklahoma and Texas,2000 Growing Season

By Jason R. Masoner1, Carol S. Mladinich2, Alexandria M. Konduris2, and S. Jerrod Smith1

03–4155

Prepared in cooperation with theBUREAU OF RECLAMATION

1U.S. Geological Survey–Water Resources Discipline2U.S. Geological Survey–Geography Discipline

Masoner, J.R., and others—

Comparison of Irrigation W

ater Use Estim

ates in the Lake Altus D

rainage Basin, O

klahoma and Texas, 2000 G

rowing Season—

USG

S/W

RIR 03–4155

Printed on recycled paper

U.S. Department of the InteriorGALE A. NORTON, Secretary

U.S. Geological SurveyCHARLES G. GROAT, Director

Any use of trade, product, and firm names in this publication is for descriptive purposes only and does not implyendorsement by the U.S. Government.

For additional information write to: Copies of this publication can be purchased from:

U.S. Geological SurveyInformation ServicesBox 25286Federal CenterDenver, CO 80225

UNITED STATES GOVERNMENT PRINTING OFFICE: OKLAHOMA CITY 2003

Additional information about water resources in Oklahoma is available on the World Wide Web athttp://ok.water.usgs.gov

District ChiefU.S. Geological SurveyWater-Resources Division202 NW 66 St., Bldg. 7Oklahoma City, OK 73116

iii

Contents

Abstract. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Purpose and scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1Description of study area. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3Previous study . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3Historical freshwater withdrawals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4Acknowledgments. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4Determination of land use and irrigated crop acres by remote sensing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7Preprocessing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9Accuracy assessment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10Suggestions to increase accuracy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10Limitations of landsat. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Remotely sensed irrigated crop acres . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11Irrigated crop acres from state water boards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11Irrigation water requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Reference evapotranspiration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14Crop evapotranspiration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16Effective precipitation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17Determination of irrigation water requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Irrigation water use calculated from remotely sensed irrigated crop acres. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18Irrigation water use calculated from state reported irrigated acres. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18Comparison of irrigation water use calculated from remotely sensed irrigated acres

with irrigation water use calculated from state reported irrigated acres. . . . . . . . . . . . . . . . . . . . . . . . . . . . 21Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24Selected references . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25Appendix. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

1. Remote sensing classification categories shown with number of pixels and acres for thepart of Beckham County, Oklahoma, in the Lake Altus drainage basin during the2000 growing season . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

2. Remote sensing classification categories shown with number of pixels and acres for thepart of Carson County, Texas, in the Lake Altus drainage basin during the2000 growing season . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

3. Remote sensing classification categories shown with number of pixels and acres for thepart of Donley County, Texas, in the Lake Altus drainage basin during the2000 growing season . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

4. Remote sensing classification categories shown with number of pixels and acres for thepart of Gray County, Texas, in the Lake Altus drainage basin during the2000 growing season . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

5. Remote sensing classification categories shown with number of pixels and acres for thepart of Greer County, Oklahoma, in the Lake Altus drainage basin during the2000 growing season . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

6. Remote sensing classification categories shown with number of pixels and acres for thepart of Kiowa County, Oklahoma, in the Lake Altus drainage basin during the2000 growing season . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

iv

7. Remote sensing classification categories shown with number of pixels and acres for thepart of Potter County, Texas, in the Lake Altus drainage basin during the2000 growing season . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35

8. Remote sensing classification categories shown with number of pixels and acres for thepart of Roger Mills County, Oklahoma, in the Lake Altus drainage basin during the2000 growing season . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36

9 Remote sensing classification categories shown with number of pixels and acres for thepart of Washita County, Oklahoma, in the Lake Altus drainage basin during the2000 growing season . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37

10. Remote sensing classification categories shown with number of pixels and acres for thepart of Wheeler County, Texas, in the Lake Altus drainage basin during the2000 growing season . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38

Figures

1. Map showing the location of the Lake Altus drainage basin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22.Landsat imageshowinganexampleofaratio-classified image.Thebrightnessofpixels

represents values for the ratio of band 4 to band 3. The brighter the pixel, the higher theratio and the healthier and greener the vegetation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

3.Schematicshowing locationsandnamesofLandsatscenesusedtoacquireLandsat7Enhanced Thematic Mapper Plus imagery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

4.Landsat imageshowingexampleofground-referencedatausedtooverlayandclassify imagery. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

5-10. Graphs showing:5. Irrigatedcropacres in theLakeAltusdrainagebasinduring the2000growingseason,

determined using remote-sensing techniques and Landsat imagery . . . . . . . . . . . . . . . . . . . . . . . . 126. Irrigatedcropacres in theLakeAltusdrainagebasinduring the2000growingseason,

reported from the Oklahoma Water Resources Board and the Texas WaterDevelopment Board. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

7. Irrigation waterusefor crops in theLake Altusdrainagebasin during the2000 growingseason, calculated from remotely sense irrigated acres . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

8. Irrigation waterusefor crops in theLake Altusdrainagebasin during the2000 growingseason, calculated from irrigated acres reported from the Oklahoma WaterResources Board and the Texas Water Development Board. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

9.Comparisonof irrigationwaterusecalculatedfromremotelysensed irrigatedacreswith irrigation water use calculated from irrigated acres reported from the OklahomaWater Resources Board and Texas Water Development Board in the Lake Altusdrainage basin during the 2000 growing season, shown by county. . . . . . . . . . . . . . . . . . . . . . . . . . 22

10.Comparisonof irrigationwaterusecalculatedfromremotelysensed irrigatedcropacreswith irrigation water use calculated from irrigated acres reported from the OklahomaWater Resources Board and Texas Water Development Board in the Lake Altusdrainage basin during the 2000 growing season, shown by crop . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Tables

1.Portionsofcounties inOklahomaandTexas in theLakeAltusdrainagebasin . . . . . . . . . . . . . . . . . . . . . . . . 42.1995estimatedfreshwaterwithdrawals forcatalogingunits11120301and11120302 . . . . . . . . . . . . . . . . . . 5

v

3. Categories of pixel classes used to define land use and irrigated crop acres in the Lake Altusdrainage basin during the 2000 growing season . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7

4. IrrigatedcropacresderivedfromremotesensingtechniquesandLandsat imagery forportionsof counties in the Lake Altus drainage basin during the 2000 growing season . . . . . . . . . . . . . . . . . . . . . 12

5. IrrigatedcropacresreportedfromtheOklahomaWaterResourcesBoardandTexasWater Development Board for portions of Oklahoma and Texas Counties in the LakeAltus drainage basin during the 2000 growing season . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

6.Weatherstationsused instudy,climatedata fromSeptember1999 toOctober2000 . . . . . . . . . . . . . . . . . 157.Referenceevapotranspiration (ETo) forcropgrowingseasons in theLakeAltusdrainage

basin during the 2000 growing season . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 168.Cropevapotranspiration (ETc) formajorcrops in theLakeAltusdrainagebasinduring the

2000 growing season . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179. Irrigation water requirements (U) formajorcrops in theLakeAltus drainagebasinduring the

2000 growing season . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1810. Irrigation water use for portion of counties in the Lake Altus drainage basin during the 2000

growing season, calculated from remotely sensed irrigated acres . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1911. Irrigation water use for portion of counties in the Lake Altus drainage basin during the 2000

growing season, calculated from irrigated acres reported from Oklahoma WaterResources Board and the Texas Water Development Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Conversion Factors and Datum

Multiply By To obtain

Length

inch (in.) 2.54 centimeter (cm)

foot (ft) 0.3048 meter (m)

mile (mi) 1.609 kilometer (km)

Area

acre 4,047 square meter (m2)

acre 0.004047 square kilometer (km2)

square mile (mi2) 2.590 square kilometer (km2)

Volume

gallon (gal) 0.003785 cubic meter (m3)

acre-foot (acre-ft) 43,560 cubic feet (ft3)

acre-foot (acre-ft) 1,233 cubic meter (m3)

Flow rate

cubic foot (ft3) 7.48 gallon (gal)

million gallons per day (Mgal/d) 0.003785 cubic meter per day (m3/d)

Watts

langleys per day (lang/day) 1,004,140.8 watts per meter squared (watts/m2)

vi

Temperature in degrees Celsius (°C) may be converted to degrees Fahrenheit (°F) as follows:

°F = (1.8 × °C) + 32

Temperature in degrees Fahrenheit (°F) may be converted to degrees Celsius (°C) as follows:

°C = (°F - 32) / 1.8

Vertical coordinate information is referenced to the North American Vertical Datum of 1988(NAVD 88).

Horizontal coordinate information is North American Datum of 1983 (NAD 83).

Comparison of Irrigation Water Use Estimates CalculatedFrom Remotely Sensed Irrigated Acres and State ReportedIrrigated Acres in the Lake Altus Drainage Basin,Oklahoma and Texas, 2000 Growing Season

By Jason R. Masoner, Carol S. Mladinich, Alexandria M. Konduris, and S. Jerrod Smith

Abstract

Increased demand for water in the Lake Altus drainagebasin requires more accurate estimates of water use for irriga-tion. The U.S. Geological Survey, in cooperation with the U.S.Bureau of Reclamation, is investigating new techniques toimprove water-use estimates for irrigation purposes in the LakeAltus drainage basin. Empirical estimates of reference evapo-transpiration, crop evapotranspiration, and crop irrigation waterrequirements for nine major crops were calculated from Sep-tember 1999 to October 2000 using a solar radiation-basedevapotranspiration model. Estimates of irrigation water usewere calculated using remotely sensed irrigated crop acresderived from Landsat 7 Enhanced Thematic Mapper Plus imag-ery and were compared with irrigation water-use estimates cal-culated from irrigated crop acres reported by the OklahomaWater Resources Board and the Texas Water DevelopmentBoard for the 2000 growing season. The techniques presentedwill help manage water resources in the Lake Altus drainagebasin and may be transferable to other areas with similar watermanagement needs.

Irrigation water use calculated from the remotely sensedirrigated acres was estimated at 154,920 acre-feet; whereas, irri-gation water use calculated from state reported irrigated cropacres was 196,026 acre-feet, a 23 percent difference. The great-est difference in irrigation water use was in Carson County,Texas. Irrigation water use for Carson County, Texas, calcu-lated from the remotely sensed irrigated acres was 58,555 acre-feet; whereas, irrigation water use calculated from statereported irrigated acres was 138,180 acre-feet, an 81 percentdifference. The second greatest difference in irrigation wateruse occurred in Beckham County, Oklahoma. Differencesbetween the two irrigation water use estimates are due to thedifferences of irrigated crop acres derived from the mappingprocess and those reported by the Oklahoma Water ResourcesBoard and Texas Water Development Board.

Introduction

Increased demand for water in the Lake Altus drainagebasin requires more accurate estimates of water use for irriga-tion. Agriculture is the primary land use in the drainage basin.Ninety-one percent of water use in the drainage basin in 1995was for irrigation purposes (R.L. Tortorelli, USGS, writtencommun., 2001). Lake Altus supplies water to the Lugert-AltusIrrigation District using a 270-mile system of canals down-stream from the dam (Oklahoma Water Resources Board,2000). Lake Altus was built by the Bureau of Reclamation from1941 to 1948 for flood control, water supply for the City ofAltus, and irrigation of about 46,000 acres (A. Ensley, Lugert-Altus Irrigation District, oral commun., 2002). The Lugert-Altus Irrigation District annually supplies more than 85,000acre-feet of water for agricultural purposes (Oklahoma WaterResources Board, 2000).

The U.S. Geological Survey, in cooperation with the U.S.Bureau of Reclamation, investigated new techniques toimprove water-use estimates for irrigation purposes in the LakeAltus drainage basin (fig. 1). Empirical estimates of referenceevapotranspiration, crop evapotranspiration, and crop irrigationwater requirements for alfalfa, corn, cotton, hay, peanuts, sor-ghum, soybeans, sunflowers, and wheat were calculated on amonthly and seasonal basis from September 1999 to October2000 using an evapotranspiration model by Doorenbos andPruitt (1977). The model is commonly referred to as the radia-tion method and is accurate in arid and sub-humid areas and lessaccurate near the ocean in cooler climates (U.S. Department ofAgriculture, 1993). These empirical estimates of irrigationwater use were used with estimated irrigated acres to calculateirrigation water use in the Lake Altus drainage basin in Okla-homa and Texas.

Purpose and Scope

The purpose of this report is to present the techniques andresults of an effort to map irrigated crop acres in the Lake Altusdrainage basin using satellite imagery and remote sensing tech-

2 Comparison of Irrigation Water Use Estimates Calculated From Remotely Sensed Irrigated Acres and State Reported Irri-gated Acres in the Lake Altus Drainage Basin, Oklahoma and Texas, 2000 Growing Season

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Introduction 3

niques, and compare irrigation water use estimates calculatedfrom the remotely sensed irrigated acres with those calculatedfrom state reported irrigated crop acres for the 2000 growingseason. This report presents: (1) mapping of land use and irri-gated crop acres from multiple dates of Landsat 7 EnhancedThematic Mapper Plus (ETM+) imagery; (2) reported irrigatedcrop acres from Oklahoma Water Resources Board (OWRB)and Texas Water Development Board (TWDB); (3) seasonalestimates of reference evapotranspiration, crop evapotranspira-tion, and crop irrigation water requirements; (4) seasonal esti-mates of irrigation water use for alfalfa, corn, cotton, hay,peanuts, sorghum, soybeans, sunflowers, and wheat; and (5) acomparison of irrigation water use estimates calculated fromremotely sensed irrigated acres and irrigation water use esti-mates calculated from the state reported irrigated acres.

Seasonal irrigation water use, referred to in this report asirrigation water use during the 2000 growing season, was calcu-lated for each crop on a countywide basis for major crops bymultiplying seasonal irrigation requirements by the number ofirrigated crop acres in each county. Irrigation water use was cal-culated using two sources of irrigated crop acres: (1) irrigatedcrop acres derived from remote sensing techniques and Landsat7 ETM+ imagery, referred to as remotely sensed irrigated acres;and (2) irrigated acres reported by the OWRB and the TWDB,referred to as state reported irrigated acres. Irrigation water useestimates calculated from remotely sensed irrigated crop acreswere compared with irrigation water use estimates calculatedfrom state reported irrigated acres for the 2000 growing season.

Estimates of water use for irrigation provided in this reportwill facilitate better management of water resources in the LakeAltus drainage basin. Methodologies described in this report tocalculate estimates of reference evapotranspiration, crop evapo-transpiration, crop irrigation water requirements, and irrigationwater use, may be transferable to other areas that may have sim-ilar water management needs. The irrigation water require-ments presented in this report can be used with estimates of irri-gated acres from anywhere in the drainage basin to calculateirrigation water use.

Description of Study Area

The study area consists of the Lake Altus drainage basin(fig.1). Lake Altus is located on the border of Greer and KiowaCounties in southwestern Oklahoma, approximately 20 milesnorth of the town of Altus. The drainage area for Lake Altus isapproximately 2,515 square miles, 399 square miles of whichare non-contributing (Blazs and others, 2001). Most of thedrainage basin, includes parts of Beckham, Carson, Gray, andWheeler Counties (table 1).

The North Fork Red River is the major source of surface-water inflow for Lake Altus. The North Fork Red River is oneof five major tributaries of the Red River. U.S. Geological Sur-vey streamflow-monitoring station 07301500, North Fork RedRiver Near Carter, Oklahoma, recorded a mean annual flow of93,230 acre-feet from 1945 through 2000 (Blazs and others,

2001). Average annual precipitation in the study area rangesfrom about 18 inches in the west at the headwaters to 26 inchesnear Lake Altus in the east (Daly and others, 1994).

Agriculture is the major land use and is mainly supportedby water from the High Plains Aquifer, also referred to as theOgallala Aquifer, and alluvial and terrace deposits along theNorth Fork Red River.

The High Plains Aquifer is an unconsolidated and semi-consolidated aquifer of Tertiary age and associated alluvial andterrace deposits are of Quaternary age (Havens and others,1985, p. 348). The High Plains Aquifer consists mostly of finesand and silts with lesser quantities of clay, gravel, and minorbeds of limestone and caliche (Hart and others, 1976). Wellyields range from 100 to 1,000 gallons per minute; with someyields exceeding 1,500 gallons per minute (Havens and others,1985, p. 347).

The North Fork Red River alluvial and Beckham andTillman terrace deposits consist of silt, clay, and gravel gradingdownward into fine to coarse sand (Havens and others, 1985, p.348). Well yields range from 100 – 200 gallons per minute inthe alluvium and 200 – 500 gallons per minute in the Beckhamand Tillman terrace (Havens and others, 1985, p. 348).

The length of growing season for crops is closely relatedto temperature and has a substantial effect on the amount ofwater used by crops. There are two primary growing seasons inthe Lake Altus drainage basin. Winter wheat is grown in thefirst growing season, which occurs from early October throughearly May (peak greenness), with harvesting in early June(McDaniels, 1960, and U.S. Department of Agriculture, 1998).Corn, cotton, peanuts, sorghum, soybeans, and sunflowers aregrown in the second growing season, which occurs from mid-March through late July to mid-August (peak greenness) withharvesting in September or November (McDaniels, 1960, andU.S. Department of Agriculture, 1998).

Previous Study

Heimes and Luckey (1982) describe a method for estimat-ing historical irrigation water requirements for the High PlainsAquifer from 1949 though 1978. There were two primarycomponents used to estimate irrigation water use; irrigated cropacres and crop irrigation requirements. The report by Heimesand Luckey (1982) acquired estimates of irrigated acres bycounty from the Census of Agriculture (U.S. Department ofCommerce, 1949 to 1978). A modified version of the Blaney-Criddle formula was used to estimate irrigation water require-ments for major crops growing above the High Plains Aquifer(U.S. Department of Agriculture, 1970). The Modified Blaney-Criddle differs from the original Blaney-Criddle in that twoadjustment factors are used to better estimate crop evapotrans-piration. A climate coefficient correlates monthly crop evapo-transpiration with the mean monthly temperature, and a growth-stage coefficient tracks crop growth development throughoutthe growing cycle. The Modified Blaney-Criddle method is

4 Comparison of Irrigation Water Use Estimates Calculated From Remotely Sensed Irrigated Acres and State Reported Irri-gated Acres in the Lake Altus Drainage Basin, Oklahoma and Texas, 2000 Growing Season

Table 1. Portions of counties in Oklahoma and Texas in the Lake Altus drainage basin

Counties State Portion of county indrainage basin (acres)

Portion of county indrainage basin (percent)

Beckham Okla. 365,310 20.4

Greer Okla. 47,686 2.7

Kiowa Okla. 32,384 1.8

Roger Mills Okla. 94,737 5.2

Washita Okla. 2,551 0.1

Carson Tex. 264,860 14.7

Donley Tex. 7,101 0.4

Gray Tex. 471,616 26.3

Randall Tex. 1,227 0.1

Potter Tex. 40,104 2.2

Wheeler Tex. 467,473 26.1

widely used because of the limited climate information neededto calculate crop evapotranspiration and has been widely usedhistorically by federal and state agriculture programs. There aremore accurate methods that use solar radiation, wind speed,temperature, and humidity data to estimate crop evapotranspira-tion (U.S. Department of Agriculture, 1970).

Historical Freshwater Withdrawals

Freshwater withdrawal estimates for 1995 were obtainedfor 8-digit Hydrologic Unit Code (HUC) 11120301 and11120302 (fig. 1) from the U.S. Geological Survey (R.L. Tor-torelli, USGS, written commun., 2001). Total consumptive usefrom the Lake Altus drainage basin was estimated to be 120,983acre-feet or 108.15 million gallons per day. Consumptive usefor irrigation was estimated to be 109,781 acre-feet or 98.24million gallons per day (table 2). Ground water supplies about69 percent of total self-supplied water withdraws in the drain-age basin; whereas, surface water accounts for the remaining 31percent. The western half (11120301) of the study areaaccounted for 61 percent of the total self-supplied withdrawalsin the drainage basin because of greater withdrawals from theHigh Plains Aquifer for irrigation. Withdrawals in the westernhalf (11120301) are predominantly supplied by ground water(94 percent); whereas, withdrawals in the eastern half(11120302) are predominantly supplied by surface water (72percent) (table 2).

Irrigation accounts for 82 percent of total self-suppliedwater withdrawals in the drainage basin. However, the majorityof surface-water withdrawals and irrigated acres in the easternhalf are utilized downstream in the Altus-Lugert Irrigation Dis-trict. The distribution of other less prevalent self-supplied with-drawals included 4.9 percent for public use, 4.5 percent for live-stock use, 4.4 percent for industrial use, 3.6 percent for mininguse, and 0.4 percent for domestic use (calculated from table 2).Detailed explanations of water use terms used in this sectioncan be acquired at URL http://ok.water.usgs.gov/wateruse/def-initions.html

Acknowledgments

The authors wish to express their appreciation to personnelfrom U.S. Department of Agriculture, Natural Resources Con-servation Service (NRCS) and Farm Service Agency (FSA)offices for providing field maps of croplands and informationabout agricultural practices that were used to calibrate remotesensing data when determining irrigated croplands. HowardJohnson, Oklahoma Climatological Survey (OCS) and CleonNapkin, NRCS, provided climate data used in this report. JerryWalker and Tom Spofford, NRCS, provided technical adviceabout the evapotranspiration model used for this report.Michael Sughru, U.S. Geological Survey made several sugges-tions to improve the remote sensing part of this report.

Introduction 5

Table 2. 1995 estimated freshwater withdrawals for cataloging units 11120301 and 11120302 (data source, R.L. Tortorelli, U.S. GeologicalSurvey, written commun., 2001)

[data units in million gallons per day (mgd) unless noted; gal/day, gallon per day]

Public supply category 1120301 1120302 Totalbasin Commercial category 1120301 1120302 Total

basin

Population served byground water, in thou-sands

7.64 20.21 27.85 Total self-supplied with-drawals, ground water

0.07 0.25 0.32

Population served by sur-face water, in thousands

4.64 0.00 4.64 Total self-supplied with-drawals, surface water

0.00 0.00 0.00

Total population served,in thousands

12.28 20.21 32.49 Total self-supplied with-drawals

0.07 0.25 0.32

Total self-supplied with-drawals, ground water

1.25 4.74 5.99 Consumptive use, total 0.04 0.10 0.14

Total self-supplied with-drawals, surface water

0.00 0.00 0.00

Total self-supplied with-drawals, total

1.25 4.74 5.99

Per-capita use, in gal/d 101.79 234.53 184.36

Domestic category 1120301 1120302 Totalbasin Industrial category 1120301 1120302 Total

basin

Self-supplied population,in thousands

1.20 1.85 3.05 Total self-supplied with-drawals, ground water

5.19 0.20 5.39

Total self-supplied with-drawals, ground water

0.26 0.21 0.47 Total self-supplied with-drawals, surface water

0.00 0.00 0.00

Total self-supplied with-drawals, surface water

0.00 0.00 0.00Total self-supplied with-drawals

5.19 0.20 5.39

Total self-supplied with-drawals

0.26 0.21 0.47 Consumptive use, total 0.34 0.04 0.38

Per-capita use, self-sup-plied, in gal/d

216.67 113.51 154.10

Per-capita use, public-sup-plied, in gal/d

194.63 95.99 133.27

Consumptive use, total 1.06 0.73 1.79

Mining category 1120301 1120302 Totalbasin Total livestock category 1120301 1120302 Total

basin

Total self-supplied with-drawals, ground water

3.65 0.73 4.38 Total self-supplied with-drawals, ground water

0.66 0.63 1.29

Total self-supplied with-drawals, surface water

0.00 0.00 0.00 Total self-supplied with-drawals, surface water

1.84 2.25 4.09

6 Comparison of Irrigation Water Use Estimates Calculated From Remotely Sensed Irrigated Acres and State Reported IrrigatedAcres in the Lake Altus Drainage Basin, Oklahoma and Texas, 2000 Growing Season

Miningcategory—Continued 1120301 1120302 Total

basinTotal livestock

category—Continued 1120301 1120302 Totalbasin

Total self-supplied with-drawals

3.65 0.73 4.38 Total self-supplied with-drawals

2.50 2.88 5.38

Consumptive use, total 2.12 0.10 2.22 Consumptive use, total 2.50 2.88 5.38

Irrigation category 1120301 1120302 Totalbasin

Reservoir evaporationcategory 1120301 1120302 Total

basin

Total self-supplied with-drawals, ground water

59.09 6.80 65.89 Reservoir surface area, inthousand acres

0.32 4.74 5.06

Total self-supplied with-drawals, surface water

2.41 31.80 34.21 Reservoir evaporation, inthousand acre-feet peryear

1.59 23.16 24.75

Total self-supplied with-drawals

61.50 38.60 100.10

Consumptive use, total 61.50 36.74 98.24

Conveyance loss 0.00 1.59 1.59Totals, overall category 1120301 1120302 Total

basin

Thousand acres irrigated,sprinkler

22.10 11.35 33.45 Total self-supplied with-drawals, ground water

70.17 13.56 83.73

Thousand acres irrigated,microirrigation

0.01 0.13 0.14 Total self-supplied with-drawals, surface-water

4.25 34.05 38.30

Thousand acres irrigated,surface water

38.06 38.73 76.79 Total self-supplied with-drawals

74.42 47.61 122.03

Thousand acres irrigated 60.17 50.21 110.38 Total consumptive use 67.56 40.59 108.15

Reclaimed wastewater 2.69 0.08 2.77 Total conveyance losses 0.00 1.59 1.59

Table 2. 1995 estimated freshwater withdrawals for cataloging units 11120301 and 11120302 (data source, R.L. Tortorelli, U.S. GeologicalSurvey, written commun., 2001)—Continued.

[data units in million gallons per day (mgd) unless noted; gal/day, gallon per day]