Edward’s Aquifer Ground-water Flow Model Texas Ground Water 2004 November 19, 2004 George B....

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Transcript of Edward’s Aquifer Ground-water Flow Model Texas Ground Water 2004 November 19, 2004 George B....

Edward’s Aquifer Ground-water Flow Model

Texas Ground Water 2004November 19, 2004George B. Ozuna

Edwards Aquifer Model

• In cooperation with: Edwards Aquifer Authority Department of Defense USGS

• Richard Lindgren, USGS• Sue Horvorka and Alan Dutton, BEG• Scott Painter, SwRI• Steve Worthington, Consultant

Edwards Aquifer Model

• Uniform ¼-mi grid • 370 rows; 700 columns; 259,000 cells• One layer• Grid alignment:

Major faults and flow near Comal and San Marcos Springs

Structure

• Aquifer top elevation• Aquifer bottom elevation• Faults

Provided by BEG – Sue Horvorka

Faults

• Simulated using Horizontal Flow Barrier Package

• Model inputs: fault location hydraulic characteristic (C)

o hydraulic conductance termo Assumption: hydraulic characteristic (C) is a

function of fault displacement inversely proportional

Las Moras Springs

Leona Springs

San Antonio & San Pedro Springs

Comal Springs

San Marcos Springs

Fault

Simulated Faults And Springs

General-head boundary

No-flow boundary – saline water line

General-head boundary

No-flow

Colorado River – Head-dependent flux boundary

No- flow

Recharge zone

Model Boundary Conditions

Hydraulic Conductivity

Provided by Southwest Research – Scott Painter

Conduits

Provided by EAA Consultant - Steve Worthington

Hydraulic Properties

Simulated Recharge Zones

Recharge Zone - Stream Channels

Pumpage – by use

Provided by BEG – Alan Dutton

Pumpage – by rate

Provided by BEG – Alan Dutton

Steady-State Calibration

• Calibration period: 1939 – 1946• Pre-1950’s drought, minimal irrigation

development• Near-normal precipitation• San Antonio precipitation: normal 1961-90 30.98 in/yr average 1939-46 30.47 in/yr

Steady-State Target Wells

144 wells

Steady-State Calibration

Transient Calibration

• Calibration period: 1947 – 2000• Calibration targets:

Long-term record wellso County Index wellso match hydrographs

Selected time periodso periods of above- and below-normal precipitationo match hydraulic heads for a set of wells

Transient Calibration

• Selected time periods Below-normal precipitation

o 1952-57 May thru November 1956 175 wells

Above-normal precipitationo 1973-77

November 1974 thru July 1975 172 wells

Transient Target Wells

Drought Conditions, 175 Wells, May – November 1956

Transient Target Wells

Wet Conditions, 172 Wells, November 1974 – July 1975

Transient Target Springs

• 5 springs simulated: San Marcos Comal Leona San Pedro* San Antonio*

*Based on relation with Bexar index well

Uvalde Index Well

Medina Index Well

Comal Well

San Marcos Well

Transient ResultsWater-Level Hydrographs

Bexar Index Well

Transient ResultsWater-Level Hydrographs

Uvalde_index(south-central Uvalde County)

810

820

830

840

850

860

870

880

890

900

910

920

930

1/1/1947

1/1/1949

1/1/1951

1/1/1953

1/1/1955

1/1/1957

1/1/1959

1/1/1961

1/1/1963

1/1/1965

1/1/1967

1/1/1969

1/1/1971

1/1/1973

1/1/1975

1/1/1977

1/1/1979

1/1/1981

1/1/1983

1/1/1985

1/1/1987

1/1/1989

1/1/1991

1/1/1993

1/1/1995

1/1/1997

1/1/1999

1/1/2001

Date

Ele

va

tio

n

Measured

Simulated

Transient ResultsWater-Level Hydrographs

Medina_6841301(east-central Medina County)

600610620630640650660670680690700710720730740750760770780

1/1/1950

1/1/1952

1/1/1954

1/1/1956

1/1/1958

1/1/1960

1/1/1962

1/1/1964

1/1/1966

1/1/1968

1/1/1970

1/1/1972

1/1/1974

1/1/1976

1/1/1978

1/1/1980

1/1/1982

1/1/1984

1/1/1986

1/1/1988

1/1/1990

1/1/1992

1/1/1994

1/1/1996

1/1/1998

1/1/2000

Date

Ele

va

tio

n

Measured

Simulated

Transient ResultsWater-Level Hydrographs

Bexar_index(central Bexar County)

600

610

620

630

640

650

660

670

680

690

700

710

1/1/1947

1/1/1949

1/1/1951

1/1/1953

1/1/1955

1/1/1957

1/1/1959

1/1/1961

1/1/1963

1/1/1965

1/1/1967

1/1/1969

1/1/1971

1/1/1973

1/1/1975

1/1/1977

1/1/1979

1/1/1981

1/1/1983

1/1/1985

1/1/1987

1/1/1989

1/1/1991

1/1/1993

1/1/1995

1/1/1997

1/1/1999

1/1/2001

Date

Ele

va

tio

n

Measured

Simulated

Transient ResultsWater-Level Hydrographs

Comal_6823701(central Comal County)

600

610

620

630

640

650

660

670

680

690

1/1/1947

1/1/1949

1/1/1951

1/1/1953

1/1/1955

1/1/1957

1/1/1959

1/1/1961

1/1/1963

1/1/1965

1/1/1967

1/1/1969

1/1/1971

1/1/1973

1/1/1975

1/1/1977

1/1/1979

1/1/1981

1/1/1983

1/1/1985

1/1/1987

1/1/1989

1/1/1991

1/1/1993

1/1/1995

Date

Ele

va

tio

n

Measured

Simulated

Transient ResultsWater-Level Hydrographs

Hays_5858101(eastern Hays County)

530540550560570580590600610620630640650660670

1/1/1947

1/1/1949

1/1/1951

1/1/1953

1/1/1955

1/1/1957

1/1/1959

1/1/1961

1/1/1963

1/1/1965

1/1/1967

1/1/1969

1/1/1971

1/1/1973

1/1/1975

1/1/1977

1/1/1979

1/1/1981

1/1/1983

1/1/1985

1/1/1987

1/1/1989

1/1/1991

1/1/1993

1/1/1995

1/1/1997

1/1/1999

1/1/2001

Date

Ele

va

tio

n

Measured

Simulated

Leona Springs

Comal Springs

San Marcos Springs

Transient ResultsSpringflow Hydrographs

Transient ResultsSpringflow Hydrographs

Comal Springs

0

5,000,000

10,000,000

15,000,000

20,000,000

25,000,000

30,000,000

35,000,000

40,000,000

45,000,000

50,000,000

1/1/1947

1/1/1949

1/1/1951

1/1/1953

1/1/1955

1/1/1957

1/1/1959

1/1/1961

1/1/1963

1/1/1965

1/1/1967

1/1/1969

1/1/1971

1/1/1973

1/1/1975

1/1/1977

1/1/1979

1/1/1981

1/1/1983

1/1/1985

1/1/1987

1/1/1989

1/1/1991

1/1/1993

1/1/1995

1/1/1997

1/1/1999

1/1/2001

Date

Flo

w in

cu

bic

fe

et

pe

r d

ay

Measured

Simulated

Transient ResultsSpringflow Hydrographs

San Marcos Springs

0

5,000,000

10,000,000

15,000,000

20,000,000

25,000,000

30,000,000

35,000,000

40,000,000

45,000,000

1/1/1947

1/1/1949

1/1/1951

1/1/1953

1/1/1955

1/1/1957

1/1/1959

1/1/1961

1/1/1963

1/1/1965

1/1/1967

1/1/1969

1/1/1971

1/1/1973

1/1/1975

1/1/1977

1/1/1979

1/1/1981

1/1/1983

1/1/1985

1/1/1987

1/1/1989

1/1/1991

1/1/1993

1/1/1995

1/1/1997

1/1/1999

1/1/2001

Date

Flo

w in

cu

bic

fe

et

pe

r d

ay

Measured

Simulated

Transient ResultsSpringflow Hydrographs

Leona Springs

0

2,000,000

4,000,000

6,000,000

8,000,000

10,000,000

12,000,000

1/1/1947

1/1/1949

1/1/1951

1/1/1953

1/1/1955

1/1/1957

1/1/1959

1/1/1961

1/1/1963

1/1/1965

1/1/1967

1/1/1969

1/1/1971

1/1/1973

1/1/1975

1/1/1977

1/1/1979

1/1/1981

1/1/1983

1/1/1985

1/1/1987

1/1/1989

1/1/1991

1/1/1993

1/1/1995

1/1/1997

1/1/1999

1/1/2001

Date

Flo

w in

cu

bic

fe

et

pe

r d

ay

Measured

Simulated

Edwards Aquifer Model

• Model Inputs Structure Boundary Conditions Hydraulic Properties Stresses

• Model Calibration Targets Steady-State Results Transient Results