HYDROCHEMICAL CHARACTERIZATION AND NUMERICAL MODELING OF GROUNDWATER FLOW IN A PART OF THE HIMALAYAN FORELAND BASIN A dissertation submitted to Kent State University in partial fulfillment of the requirements for the degree of Doctor of Philosophy By Muhammad Asim December, 2005 Dissertation written by Muhammad Asim B.Sc. (Honors), University of Peshawar, 1992 M. Sc., University of Peshawar, 1993 M. Phil., University of Peshawar, 1997 Ph.D., Kent State University, 2005 Approved by Dr. Peter Dahl, Chair, Doctoral Dissertation Committee Dr. Yoram Eckstein, Member, Doctoral Dissertation Committee Dr. Neil Wells, Member, Doctoral Dissertation Committee Dr. Mandy Munro-Stasiuk, Member, Doctoral Dissertation Committee Dr. Eugene C. Gartland, Member, Doctoral Dissertation Committee Accepted by Dr. Donald F. Palmer, Chair, Department of Geology Dr. Jerry Feezel, Dean, College of Arts and Sciences ii TABLE OF CONTENTS List of Figures ……………………………………………………………………...........vi List of Tables ……………………………………………………………………………xi ACKNOWLEDGEMENTS …………………………………………………………….xii CHAPTER 1 INTRODUCTION………………………………………………………...1 1.1 Objectives of the study…………………………………………….1 1.2 Significance of the research……………………………………….4 1.3 The study area……………………………………………………..5 1.4 The Himalayan Foreland Basin…………………………………...9 1.5 Literature review…………………………………………………11 1.6 Field and analytical procedures………………………………….14 2 TECTONICS AND STRATIGRAPHY…………………………………22 2.1 Tectonic framework……………………………………………...22 2.2 Stratigraphy………………………………………………………26 2.3 The Peshawar intermontane basin……………………………….38 iii 3 HYDROGEOLOGY……………………………………………………..42 3.1 General hydrogeology……………………………………………42 3.2 Groundwater geology in the Peshawar Basin……………………56 3.3 Peshawar Basin aquifers...……………………………………….64 3.3.1 Peshawar piedmont aquifer………………………………64 3.3.2 Peshawar lacustrine aquifer……………………………...65 3.3.3 Peshawar floodplain/stream channel aquifer…………….65 4 HYDROCHEMISTRY…………………………………………………..68 4.1 Physico-chemical parameters…………………………………….68 4.1.1 Water surface temperature……………………………….68 4.1.2 pH distribution…………………………………………...77 4.1.3 Conductivity and Total Dissolved Solids………………..77 4.2 Groundwater classification………………………………………82 4.3 Geothermometry…………………………………………………97 5 NUMERICAL SIMULATIONS………………………………………..105 5.1 Groundwater flow in basins under compressive regimes………105 5.2 Abnormal fluid pressures……………………………………….107 5.3 Groundwater Modeling System………………………………...108 5.4 Formulation of FEMWATER…………………………………..110 5.5 Boundary conditions……………………………………………113 iv 5.6 GMS Modeling approach………………………………………117 5.6.1 The conceptual model approach………………………..118 5.6.2 Initial conditions………………………………………..119 5.6.3 Time control parameters………………………………..120 5.7 Application of the model to the Himalayan foreland…………...121 5.8 Model parameters……………………………………………….124 5.8.1 Running the model……………………………………...127 5.8.2 Computed vs. observed values………………………….128 5.8.3 Error vs. time step……………………………………....128 5.8.4 Parameter sensitivity……………………………………139 5.8.5 Calibration targets………………………………………141 5.9 Modeling results………………………………………………...143 6 DISCUSSION AND CONCLUSIONS………………………………...149 6.1 Discussion………………………………………………………149 6.2 Conclusions……………………………………………………..154 6.3 Future work……………………………………………………..155 REFERENCES…………………………………………………………………………157 APPENDIX A………………………………………………………………………….170 APPENDIX B…………………………………………………………………………..179 v LIST OF FIGURES Figure Page 1.1: Index map of Pakistan showing the location of the study area………………........3 1.2: Map showing location of deep water wells and drainage system in southern part of the study area…………………....……………………………….7 1.3: Map of the major faults and sampling sites in the Peshawar Basin and environs superimposed on shaded relief map of the study area…..……9 1.4: Determination of physico-chemical characteristics of groundwater in the field……………………………………………….……………………….17 1.5: Calibration curves obtained for major ions analyzed in groundwater samples by ICP ………………………………….………………………………18 1.6: Calibration curves obtained for trace elements analyzed in groundwater samples by ICP ………………………………...……………………………......19 1.7: Calibration curve and relevant data for DIONEX Ion Chromatograph………….20 1.8: Calibration curve and relevant data for the TOC Analyzer……………………...21 2.1: Structural map of the study area showing major thrust zones.…………………..24 2.2: Geologic map of the study area showing prominent lithologies…………………28 2.3: Columnar sections of the sedimentary sequences in the Salt Range ……………29 2.4: Dissolved evaporites of Bahadur Khel Salt as seen on this river bed in the vicinity of Kohat, south of Peshawar Basin……..……………………30 2.5: Generalized stratigraphy of the Kohat-Potwar area………..…………………….32 2.6: Red sandstones and clays of the Siwalik Group in the Kohat-Potwar plateau of north Pakistan…………...………………………………..……….. …34 vi 2.7: Precambrian metasedimentary series (Salkhalas) exposed on the northern edge of Peshawar basin…………………………………………………………..35 2.8: The Precambrian metamorphic series intruded by post-collisional granites (Malakand area)…...……………………………………………………………..36 2.9: Late Paleozoic metasedimentary rocks of the Eurasian Mass north of the MKT, showing spectacular minor folding...……………………………………..37 2.10: Late Proterozoic to Early Paleozoic metamorphic sequence exposed on the southern margin of the Peshawar Basin...………………………………………..40 2.11: Cross section A-A', extending from the Peshawar basin to the western Salt Range………………………………. ………………………………………41 3.1: Water table elevation (in meters) varies considerably in the area……………….43 3.2: The only dug well in Chitral area, located at Mastuj Fort…...…………………..44 3.3: Large sediment load, carried by Chitral River because of high discharge and steep gradients……………………………………………..………………...46 3.4: A small spring in the Early Paleozoic rocks (limestone) in the Attock-Cherat Ranges on the southern margin of Peshawar basin………………47 3.5: Seepage appearing in the Khyber Slate series along the eastern margin of Peshawar basin, just south of Pakistan-Afghanistan border…………………..48 3.6: Spring appearing in alluvium along the Main Swat Road, north of Mingora…………………………………………………………………49 3.7: Largest spring in the study area, located just north of Chitral, which provides most of the drinking water to the city…..……………………………...50 3.8: A small spring appearing in alluvium along the Booni-Chitral road……………51 3.9: The surface expression of this spring is in a glacial till in the town of Mastuj….52 3.10: This spring appears in the Permian Slate series of the Eurasian mass along the Chitral-Garam Chashma road……..…………………………………..53 3.11: This spring appears in the Paleogene Garam Chashma granodiorite. …………..54 vii 3.12: Hot springs at Garam Chashma, yielding a surface temperature of 70 °C………55 3.13a: Drilled wells known as tube wells and used extensively for irrigation purposes……………………………………………………………….57 3.13b: An operational tube well in the Tarbela area…………………………………….58 3.14: Dug wells, which are most commonly used for domestic purposes and are very susceptible to contamination..…………………………………………..59 3.15: Topographic map of Peshawar basin showing major localities and rivers (contour values given in meters)……….……………………………..61 3.16: Fence diagram constructed from borehole data in the Peshawar Basin……………………………..……………………………………63 3.17: Confluence of Kabul and Indus Rivers at the eastern margin of Peshawar Basin……………………………………………………………………………..67 4.1: Index map of the sampling sites………………………………………………….69 4.2: Distribution of groundwater temperature recorded at the surface (°C).…………70 4.3: Mean annual air temperature based on data from 19 recording stations (°C)…...71 4.4: Distribution of the difference between water surface temperature and mean annual air temperature (∆T °C)………………………………………………….72 4.5: Distribution of pH values in the study area…...…………………………………74 4.6: Distribution of electrical conductivity (EC) values in the study area (micro S/cm)……………………………………………………………………………..76 4.7: Total Dissolved Solids (TDS) distribution in the area (mg/l)……………………77 4.8: Piper (1944) diagram for spring water samples………...………………………..79 4.9: Piper (1944) diagram for shallow well water samples…………………….….….80 4.10: Piper (1944) diagram for deep well water samples………………… …….…....81 4.11: Hounslow (1995) brine differentiation plot, superimposed by data points for deep well water samples…………………………………………….…….….82 viii 4.12: Hounslow (1995) brine differentiation plot superimposed by data points for shallow well water samples..….............................................................83 4.13: Hounslow (1995) brine differentiation plot superimposed by data points for spring water samples…………………………………………… …….……..84 4.14: Map of SiO2 concentrations (in mg/L)………………...…………………………86 4.15: Map of boron concentrations (in mg/L)……………..…………………………...87 4.16: Map of strontium concentrations (in mg/L)………….…………………………..88 4.17: Source reservoir temperature of groundwater calculated from chalcedony geothermometry……………………………………………………………….....91 4.18: Source reservoir temperature of groundwater calculated from Mg-corrected Na-K-Ca geothermometry……………………………………………………....92 4.19: Relationship between temperature anomaly and silica concentration in spring water……………………………………………………………..…….93 4.20: Relationship between temperature anomaly and boron concentration in spring water……………………………………………………………………93 4.21: Relationship between temperature anomaly and Sr concentration in spring water………………………………………………………………………94 4.22 Relationship between temperature anomaly and Li concentration in spring water………………………………………………………………………94