use of gms environment for numerical modeling of groundwater. modflow and modpath flow and transport models

1. Groundwater Modeling System
Presented by
Chandra Vanshi Thakur(17WM60R07)
Shyam Mohan Chaudhary(17AG62R13)
Visuto Khatso(17AG62R14)
Rajnish Singh(17AG62R18)

2. UTILITY OF THE MODEL
• Comprehensive graphical user environment for
performing groundwater simulations.
• provides tools for every phase of a simulation
– site characterization,
– model development,
– calibration,
– post-processing and
– visualization.

3. GMS CAN BE DOWNLOADED FROM
https://www.aquaveo.com/downloads
co
Contains all core
components, all tools
of site characterization,
additional models and
ARC-GIS extensions

4. MODEL FRAMEWORK
• Several numerical models are currently supported in
GMS.
• MODFLOW
– MODFLOW is a 3D, cell-centered, finite difference,
saturated flow model developed by the USGS.
– The governing equation (partial-differential flow
equation) can be approximated by replacing the
derivatives with finite differences.

5. continued…
Governing Groundwater flow equation
The saturated flow modeling is based transient on the three-
dimensional Darcy equation
where Kxx, Kyy, Kzz are the hydraulic conductivity along the x, y
and z axes ,
h is the hydraulic head,
Q represents the source/sink terms, and
S is the storage coefficient

7. MODPATH

8. OTHER TRANSPORT MODELS
• MT3DMS
• RT3D
• SEAM3D
• MODAEM
• FEMWATER
• SEEP2D

9. INPUT DATA REQUIREMENTS
• Base map.
• Boundary conditions.
• Rainfall and evaporation data for the entire study
area.
• Groundwater level to define the initial and boundary
condition and for calibration and validation.
• Aquifer properties.
• Groundwater abstraction data.

10. INPUT DATA REQUIREMENTS
• The input file formats
– ASCII files (.TXT, .ASC, .DAT),
– MS Access Database files (.MDB),
– MS Excel files (.XLS),
– ESRI Point files (.SHP),
– USGS DEM files (.DEM),
– ESRI grid files (.GRD)
– http://india-wris.nrsc.gov.in/
– https://www.ncdc.noaa.gov/cdo-web/
– http://www.indiawaterportal.org/met_data/

11. OUTPUT DATA
• Hydraulic Heads
• Drawdown
• Flow rates
• Mass Balance
• Iteration information.
• The velocity vectors, path lines, water table contours,
concentration contours can be seen in 2D or 3D
according to the selection.

12. MODEL RUN (step by step)

13. SAMPLE PROBLEM

14. EXTRA AVAILABLE DATA
• Vertical anisotropy (Kh/Kv)
– Layer 1 = 10
– Layer 2 = 5
• Grid size : 22860 m x 22860 m.
• Cell size : 1524 m x 1524 m.
• Grid consists of 15 rows and 15 columns.
• Top layer wells: 12 with discharge 12230 m3/day each
• Middle layer wells: 2 with discharge 12230 m3/day each
• Bottom layer well: 1 with discharge 0.15 m3/day

15. EXTRA AVAILABLE DATA
• LAKE : Constant head
boundary on the left.
(first two layers) (30 cells)
• Starting heads will be set
equal to zero
• Steady state solution will
be computed.
DRAIN

16. MODELING WITH GRID APPROACH
• Units
• Creating the Grid
• Creating the MODFLOW simulation
• Assigning IBOUND values directly to cells
• LPF package
• Recharge Package
• Drain Package
• Well Package
• Checking and saving the simulation
• Running MODFLOW
• Viewing the solution
• Zone Budget
• Conclusion

17. MODEL INTERFACE

18. SETTING UP UNITS

19. SETTING UP UNITS

20. SETTING UP UNITS

21. CREATING THE GRID

22. CREATING THE GRID

23. CREATING THE GRID

24. CREATING THE MODFLOW
SIMULATION

25. CREATING THE MODFLOW
SIMULATION

26. CREATING THE MODFLOW
SIMULATION

27. THE IBOUND ARRAY

28. THE IBOUND ARRAY

29. THE IBOUND ARRAY

30. TOP AND BOTTOM ELEVATIONS

31. TOP AND BOTTOM ELEVATIONS

32. TOP AND BOTTOM ELEVATIONS

33. TOP AND BOTTOM ELEVATIONS

34. TOP AND BOTTOM ELEVATIONS

35. ASSIGNING IBOUND VALUES DIRECTLY
TO CELLS-VIEWING THE LEFT COLUMN

36. SELECTING THE CELLS

37. CHANGING THE IBOUND VALUE

38. CHANGING THE IBOUND VALUE

39. CHANGING THE IBOUND VALUE

40. CHANGING THE IBOUND VALUE

41. THE LPF PACKAGE

42. ENTRIES FOR THE TOP LAYER

43. ENTRIES FOR THE TOP LAYER

44. MIDDLE AND BOTTOM LAYER

45. THE RECHARGE PACKAGE

46. THE RECHARGE PACKAGE

47. THE DRAIN PACKAGE

48. THE DRAIN PACKAGE

49. THE DRAIN PACKAGE

50. THE DRAIN PACKAGE

51. THE DRAIN PACKAGE

52. THE DRAIN PACKAGE

53. THE WELL PACKAGES-TOP LAYER
PACKAGE

54. THE WELL PACKAGES-TOP LAYER
PACKAGE

55. THE WELL PACKAGES-TOP LAYER
PACKAGE

56. MIDDLE LAYER WELLS

57. MIDDLE LAYER WELLS

58. MIDDLE LAYER WELLS

59. CHECKING AND SAVING THE
SIMULATION

60. CHECKING AND SAVING THE
SIMULATION

61. CHECKING AND SAVING THE
SIMULATION

62. CHECKING AND SAVING THE
SIMULATION

63. CHECKING AND SAVING THE
SIMULATION

64. CHECKING AND SAVING THE
SIMULATION

65. RUNNING MODFLOW

66. RUNNING MODFLOW

67. VIEWING THE SOLUTION

68. CHANGING LAYERS

69. CHANGING LAYERS

70. COLOR FILL CONTOURS AND COLOR
LEGEND

71. COLOR FILL CONTOURS AND COLOR
LEGEND

72. COLOR FILL CONTOURS AND COLOR
LEGEND

73. Color Fill Contours and Color Legend

74. COLOR FILL CONTOURS AND COLOR
LEGEND

75. COLOR FILL CONTOURS AND COLOR
LEGEND

76. COLOR FILL CONTOURS AND COLOR
LEGEND

77. COLOR FILL CONTOURS AND COLOR
LEGEND

78. VIEWING THE FLOW BUDGET

79. VIEWING THE FLOW BUDGET

80. VIEWING THE FLOW BUDGET

81. VIEWING THE FLOW BUDGET

82. CASE STUDY
Modelling groundwater flow and advective
contaminant transport in the Bou-Areg
unconfined aquifer (NE Morocco)

83. PROBLEM STATEMENT
• Since the groundwater there has been severely
contaminated by salinization, most water for agricultural
purposes is drawn from the river.
• Effective strategies for both management and protection
of groundwater resources are required to avoid future
irreversible environmental impacts, such as depletion
and deterioration of groundwater quality.

84. OBJECTIVES
• To employ MODFLOW within the framework of the
GMS to study the groundwater processes of the
hydrogeological system of Bou-Areg unconfined
aquifer
• To perform particle tracking in the aquifer using
MODPATH inside GMS framework .

85. METHODOLOGY
STUDY AREA
• The plain of Bou-Areg is located on the Mediterranean coast
of northeastern Morocco.
• The coastal plain of Bou-Areg covers 160 km2.
• The waters of the lagoon are very salty, with average salinity
levels between 37 g/l and 42 g/l during the past thirty years.
• The climate of the study area is semi-arid to humid. Average
annual precipitation is around 346 mm.

87. Data preparation
• Analysis of pumping tests.
– The Neuman and Theis solutions are applied to obtain
 hydraulic conductivity (1.1 × 10−6 to 5 × 10−4 m/s)
 storage coefficient (1.30 × 10−4 and 3 × 10−2)
 Vertical anisotropy (3 to 15)
The water balance technique is used to estimate the recharge
(9.2 × 106 m3/year)
R=P−Q −RET −ΔW
Mod el s etu p
• finite-difference model grid (500 m x 500 m) 28 rows and 53 columns.
• layer one thickness between 5 and 11 m.
• layers two and three, which are each 25 m thick.

88. BOUNDARY CONDITIONS
Grid, model boundary conditions and recharge zones of Bou-Areg aquifer system

89. Outcomes

90. Estimated hydraulic conductivity (in 10−4 m/s) of layer 1 of Bou-Areg aquifer (obtained
from PEST optimization method)

91. Estimated hydraulic conductivity (in 10−4 m/s) of layer 2 of Bou-Areg aquifer (obtained
from PEST optimization method).

92. Scatter plot of observed weighted versus computed weighted values of
head for steady state calibration flow model (1990).

93. WATER BALANCE
The water budget of the entire aquifer obtained from the
groundwater flow model

94. PARTICLE TRACKING SIMULATION

95. CONCLUSIONS
• The results of the model calibration show reasonable
agreement between observed and calculated water
levels for the observation wells.
• The horizontal hydraulic conductivity, obtained from the
model calibration, ranges between 3 × 10−4 and
2 × 10−6 m/s.
• The model aquifer is more sensitive to recharge than to
hydraulic conductivities and storativity.
• The MODPATH results show that migration of pollutants
from the upstream of the aquifer towards the lagoon is
very slow and could attain the Bou-Areg lagoon in 1000
years.

96. FUTURE SCOPE
• Since MODFLOW is based on FORTRAN
programming language which is generally
sophisticated, so attempts should be made to
code the MODFLOW in user friendly language
• Since GMS involves the use of various models
flow, transport and optimization, A DSS should
be generated to assist and help decision makers
in decision making process

97. THANK YOU…