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In cooperation with the Texas Water Development Board and the
Harris-Galveston Coastal Subsidence District

Hydrogeology and Simulation of Ground-Water Flow and Land-Surface Subsidence in the Northern Part of the Gulf Coast Aquifer System, Texas

By Mark C. Kasmarek and James L. Robinson

U.S. Geological Survey
Scientific Investigations Report 2004–5102


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pdf (29 MB)

appendix pdf (73.3 KB)


Contents

Abstract

Introduction

Purpose and Scope

Previous Studies

Description of Ground-Water Availability Model Area

Acknowledgments

Hydrogeology of the Northern Part of the Gulf Coast Aquifer System

Hydrogeologic Units and Geologic Setting

Hydraulic Properties

Ground-Water-Flow Conditions, Recharge, and Discharge

Ground-Water Development

Potentiometric Surfaces and Land-Surface Subsidence

Simulation of Ground-Water Flow and Land-Surface Subsidence in the Northern Part of the Gulf Coast Aquifer System

Model Description

Mathematical Representation

Grid Design

Boundaries

Lateral and Base of System

Recharge and Discharge

Initial Conditions

Heads

Hydraulic Properties Associated With Ground-Water Flow

Land-Surface Subsidence and Storage in Clays

Withdrawals

Model Calibration

Model Results

Simulated Hydraulic Properties Associated With Ground-Water Flow and Subsidence

Simulated and Measured Potentiometric Surfaces, 1977, 2000; and Simulated Predevelopment Surface

Simulated and Measured Hydrographs

Simulated and Estimated Water-Budget Components

Simulated and Measured Land-Surface Subsidence

Sensitivity Analysis

Model Limitations

Assumptions

Input Data

Scale of Application

Summary

Selected References

Appendix—Sources and Methods for Distributing Withdrawals for the Ground-Water Availability Model

Municipal Withdrawals

Manufacturing, Mining, and Power-Generation Withdrawals

Livestock Withdrawals

Irrigation Withdrawals

County-Other Withdrawals

List of Sources by County

Figures

1–4.  
Maps showing:
1.  
Location of Ground-Water Availability Model (GAM) area
2.  
Location of regional water planning groups in the Ground-Water Availability Model area
3.  
Location of land-surface subsidence and ground-water conservation districts in the Ground-Water Availability Model area
4.  
Location of natural subregions and river basins in the Ground-Water Availability Model area
5.  
Section showing stratigraphic units that crop out and hydrogeologic units in the Grimes-Harris-Galveston Counties area of the Ground-Water Availability Model area
6.  
Map showing surficial geology in the part of the Ground-Water Availability Model area coincident with the aquifer system
7.  
Chart showing correlation of stratigraphic and hydrogeologic units
8–27.  
Maps showing:
 
8.  
Extent and outcrop area of the Chicot aquifer in the Ground-Water Availability Model area
 
9.  
Altitude of the top of the Chicot aquifer in the Ground-Water Availability Model area
 
10.  
Altitude of the base of the Chicot aquifer in the Ground-Water Availability Model area
 
11.  
Thickness of the Chicot aquifer in the Ground-Water Availability Model area
 
12.  
Cumulative clay thickness of the Chicot aquifer in the Ground-Water Availability Model area
 
13.  
Cumulative sand thickness of the Chicot aquifer in the Ground-Water Availability Model area
 
14.  
Extent, outcrop area, and subcrop area of the Evangeline aquifer in the Ground-Water Availability Model area
 
15.  
Altitude of the top of the Evangeline aquifer in the Ground-Water Availability Model area
 
16.  
Altitude of the base of the Evangeline aquifer in the Ground-Water Availability Model area
 
17.  
Thickness of the Evangeline aquifer in the Ground-Water Availability Model area
 
18.  
Cumulative clay thickness of the Evangeline aquifer in the Ground-Water Availability Model area
 
19.  
Cumulative sand thickness of the Evangeline aquifer in the Ground-Water Availability Model area
 
20.  
Extent, outcrop area, and subcrop area of the Burkeville confining unit in the Ground-Water Availability Model area
 
21.  
Extent, outcrop area, and subcrop area of the Jasper aquifer in the Ground-WaterAvailability Model area
 
22.  
Altitude of the top of the Jasper aquifer in the Ground-Water Availability Model area
 
23.  
Altitude of the base of the Jasper aquifer in the Ground-Water Availability Model area
 
24.  
Thickness of the Jasper aquifer in the Ground-Water Availability Model area
 
25.  
Cumulative clay thickness of the Jasper aquifer in the Ground-Water Availability Model area
 
26.  
Cumulative sand thickness of the Jasper aquifer in the Ground-Water Availability Model area
 
27.  
Salt-dome locations in the Ground-Water Availability Model area
28.  
Hydrographs of wells in the Ground-Water Availability Model area screened in the outcrops of (a) the Chicot aquifer in Montgomery County and (b) the Evangeline aquifer in Liberty County
29–32.  
Maps showing:
 
29.  
Measured 2000 potentiometric surface of the Chicot aquifer in the Ground-Water Availability Model area
 
30.  
Measured 2000 potentiometric surface of the Evangeline aquifer in the Ground-Water Availability Model area
 
31.  
Measured 2000 potentiometric surface of the Jasper aquifer in the Ground-Water Availability Model area
 
32.  
Finite-difference grid used for the Ground-Water Availability Model
33.  
Graphs showing total ground-water withdrawals used in transient Ground-Water Availability Model simulations by stress periods, 1891–2000
34–50.  
Maps showing:
 
34.  
Simulated transmissivity of the Chicot aquifer in the Ground-Water Availability Model area
 
35.  
Simulated transmissivity of the Evangeline aquifer in the Ground-Water Availability Model area
 
36.  
Simulated transmissivity of the Burkeville confining unit in the Ground-Water Availability Model area
 
37.  
Simulated transmissivity of the Jasper aquifer in the Ground-Water Availability Model area
 
38.  
Simulated storativity of the Chicot aquifer in the Ground-Water Availability Model area
 
39.  
Simulated storativity of the Evangeline aquifer in the Ground-Water Availability Model area
 
40.  
Simulated storativity of the Burkeville confining unit in the Ground-Water Availability Model area
 
41.  
Simulated storativity of the Jasper aquifer in the Ground-Water Availability Model area
 
42.  
Simulated vertical hydraulic conductance between water table and deeper zones of the hydrogeologic units in the Ground-Water Availability Model area
 
43.  
Simulated leakance between the Chicot and Evangeline aquifers in the Ground-Water Availability Model area
 
44.  
Simulated leakance between the Evangeline aquifer and the Burkeville confining unit in the Ground-Water Availability Model area
 
45.  
Simulated leakance between the Burkeville confining unit and the Jasper aquifer in the Ground-Water Availability Model area
 
46.  
Simulated inelastic clay storativity of the Chicot aquifer in the Ground-WaterAvailability Model area
 
47.  
Simulated inelastic clay storativity of the Evangeline aquifer in the Ground-Water Availability Model area
 
48.  
Simulated and measured 1977 potentiometric surfaces of the Chicot aquifer and 1977 water-level measurements from wells screened in the Chicot aquifer in the Ground-Water Availability Model area
 
49.  
Simulated and measured 1977 potentiometric surfaces of the Evangeline aquifer and 1977 water-level measurements from wells screened in the Evangeline aquifer in the Ground-Water Availability Model area
 
50.  
Simulated 1977 potentiometric surface of the Jasper aquifer and 1977 water-level measurements from wells screened in the Jasper aquifer in the Ground-Water Availability Model area
51.  
Graph showing relations between simulated and measured 1977 heads for the Chicot, Evangeline, and Jasper aquifers in the Ground-Water Availability Model
52–57.  
Maps showing:
 
52.  
Distribution of water-level (head) residuals (measured minus simulated heads) for the Chicot aquifer, 1977, in the Ground-Water Availability Model area
 
53.  
Distribution of water-level (head) residuals (measured minus simulated heads) for the Evangeline aquifer, 1977, in the Ground-Water Availability Model area
 
54.  
Distribution of water-level (head) residuals (measured minus simulated heads) for the Jasper aquifer, 1977, in the Ground-Water Availability Model area
 
55.  
Simulated and measured 2000 potentiometric surfaces of the Chicot aquifer and 2000water-level measurements from wells screened in the Chicot aquifer in the Ground-Water Availability Model area
 
56.  
Simulated and measured 2000 potentiometric surfaces of the Evangeline aquifer and 2000 water-level measurements from wells screened in the Evangeline aquifer in the Ground-Water Availability Model area
 
57.  
Simulated and measured 2000 potentiometric surfaces of the Jasper aquifer and 2000 water-level measurements from wells screened in the Jasper aquifer in the Ground-Water Availability Model area
58.  
Graph showing relations between simulated and measured 2000 heads for the Chicot, Evangeline, and Jasper aquifers in the Ground-Water Availability Model
59–65.  
Maps showing:
 
59.  
Distribution of water-level (head) residuals (measured minus simulated heads) for the Chicot aquifer, 2000, in the Ground-Water Availability Model area
 
60.  
Distribution of water-level (head) residuals (measured minus simulated heads) for the Evangeline aquifer, 2000, in the Ground-Water Availability Model area
 
61.  
Distribution of water-level (head) residuals (measured minus simulated heads) for the Jasper aquifer, 2000, in the Ground-Water Availability Model area
 
62.  
Simulated predevelopment potentiometric surface of the Chicot aquifer in the Ground-Water Availability Model area
 
63.  
Simulated predevelopment potentiometric surface of the Evangeline aquifer in the Ground-Water Availability Model area
 
64.  
Simulated predevelopment potentiometric surface of the Jasper aquifer in the Ground-Water Availability Model area
 
65.  
Locations of wells with hydrographs in the Ground-Water Availability Model area
66–71.  
Hydrographs showing simulated and measured water levels in selected observation wells screened in the:
 
66.  
Chicot aquifer in Galveston and Harris Counties in the Ground-Water Availability Model area
 
67.  
Evangeline aquifer in Harris County in the Ground-Water Availability Model area
 
68.  
Jasper aquifer in Harris and Montgomery Counties in the Ground-Water Availability Model area
 
69.  
Chicot aquifer in Wharton, Matagorda, and Hardin Counties in the Ground-Water Availability Model area
 
70.  
Evangeline aquifer in Jasper and Hardin Counties in the Ground-Water Availability Model area
 
71.  
Jasper aquifer in Tyler, Polk, Grimes, and Colorado Counties in the Ground-Water Availability Model area
72–74.  
Diagrams showing:
 
72.  
Simulated 1977 water-budget components of the hydrogeologic units in the Ground-Water Availability Model area
 
73.  
Simulated 2000 water-budget components of the hydrogeologic units in the Ground-Water Availability Model area
 
74.  
Simulated predevelopment water-budget components of the hydrogeologic units in the Ground-Water Availability Model area
75.  
Map showing simulated and measured 2000 land-surface subsidence in the Ground-Water Availability Model area
76.  
Map showing simulated and measured 2000 land-surface subsidence in the Houston area of the Ground-Water Availability Model area
77.  
Graph showing sensitivity of calibrated-model responses to changes in selected model input data

Tables

1.  
Ground-water withdrawal (stress) periods used in the Ground-Water Availability Model
2.  
Number of water-level (head) measurements and root-mean-square errors of simulated water levels in the Chicot, Evangeline, and Jasper aquifers, 1977 and 2000

Vertical Datum

Vertical coordinate information is referenced to the National Geodetic Vertical Datum of 1929 (NGVD 29).
Horizontal coordinate information is referenced to the North American Datum of 1983 (NAD 83).

Notes on units, hydraulic conductivity and transmissivity:
Hydraulic conductivity: The standard unit for hydraulic conductivity is cubic foot per day per square foot of aquifer cross-sectional area, (ft3/d)/ft2. In this report, the mathematically reduced form, foot per day (ft/d), is used for convenience.

Transmissivity: The standard unit for transmissivity is cubic foot per day per square foot times foot of aquifer thickness, [(ft3/d)/ft2]ft. In this report, the mathematically reduced form, foot squared per day (ft2/d), is used for convenience.




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