ABSTRACT ........................................................ i
ZUSAMMENFASSUNG ................................................ ii
 ......................................................... iii
ACKNOWLEDGMENTS ................................................ iv
LIST OF FIGURES .............................................. viii
LIST OF TABLES ................................................. iv
ABREVIATIONS .................................................... x
1 CHAPTER: INTRODUCTION ........................................ 1
1.1 Motivation .............................................. 1
1.2 The Goal of the Study and Hypotheses .................... 4
2 CHAPTER: STUDY AREA .......................................... 6
2.1 Topography .............................................. 6
2.2 Demography .............................................. 7
2.3 Maps System and Data Source ............................. 7
2.4 Hydrology ............................................... 7
2.4.1 Climate of Dhofar Governorate .................... 7
2.4.2 Climate data source .............................. 8
2.4.3 Temperature ...................................... 9
2.4.4 Evaporation and relative humidity ................ 9
2.4.5 Rainfall ......................................... 9
2.5 Surface Water .......................................... 11
2.5.1 Wadi flow ....................................... 11
2.6 Geological Structure and Units Classifications ......... 13
2.6.1 Geological structure ............................ 14
2.6.2 Geological units classifications ................ 16
2.6.3 Recent alluvium ................................. 17
2.6.4 Fars Group ...................................... 17
2.6.5 Hadhramaut Group ................................ 18
2.6.5.1 The Dammam Formation ................... 19
2.6.5.2 The Rus Formation ...................... 21
2.6.5.3 The Umm er Radhuma Formation ........... 21
2.6.6 Shammar Shale ................................... 24
3 CHAPTER: AQUIFER PROPERTIES AND DEVELOPMENT OF GROUNDWATER
LEVELS ...................................................... 25
3.1 Description of Hydrogeological Units ................... 25
3.2 Aquifers Characteristics ............................... 26
3.2.1 Aquifer A ....................................... 27
3.2.2 Aquifer В ....................................... 29
3.2.3 Aquifer С ....................................... 31
3.2.4 Aquifer D ....................................... 33
3.3 Groundwater Movement ................................... 34
3.4 Indications for Trends of Water Level .................. 37
3.4.1 Aquifer A ....................................... 38
3.4.2 Aquifer В ....................................... 40
3.4.3 Aquifer С ....................................... 41
3.4.4 Aquifer D ....................................... 44
3.5 Recharge Processes ..................................... 46
3.5.1 Evidence of recharge associated with cyclone
events .......................................... 46
3.6 Conclusion ............................................. 54
4 CHAPTER: GROUNDWATER ASSESSMENT AND MECHANISMS OF
RECHARGE WITHIN THE AQUIFERS ................................ 55
4.1 Sampling and Analytical Methods ........................ 55
4.2 Data Choices ........................................... 60
4.3 Correlation Matrix and Factor Analysis ................. 63
4.4 Evaluation of the Groundwater Hydrochemistry ........... 67
4.4.1 Characterisation of water types ................. 67
4.4.2 Hydrochemical signature ......................... 71
4.4.3 Trace Elements .................................. 76
4.4.4 Saturation Index (SI) ........................... 78
4.4.5 Lithology of aquifer matrixes ................... 81
4.5 Environmental Isotopes in Groundwater of the Najd
Aquifers ............................................... 87
4.5.1 Stable isotopes of water and tritium ............ 87
4.5.2 Sulphate and oxygen isotopes of sulphate ........ 93
4.6 Multiple Influences on Groundwater Recharge
Processes ............................................. 102
4.6.1 Groundwater flow dynamic in the upper aquifer
A .............................................. 102
4.6.2 Faults influences in the groundwater flow and
behavior ....................................... 103
4.6.3 Hydrochemistry and isotopes evidences .......... 104
4.6.4 Recharge direction ............................. 111
4.7 Water Quality ......................................... 112
4.7.1 Potable water .................................. 113
4.7.1.1 Fluoride source and distribution ...... 114
4.7.1.2 Nitrate ............................... 119
4.7.1.3 otal Hardness ......................... 119
4.7.2 Irrigation water for agriculture purposes ...... 120
4.7.2.1 Salinity .............................. 120
4.7.2.2 Cl/Br ratio ........................... 122
4.7.2.3 Sodium Adsorption Ratio (SAR) ......... 123
4.8 Conclusion ............................................ 126
5 CHAPTER: EVALUATION OF GROUNDWATER AGE IN ALL
AQUIFERS WITH REGARDS TO PALEO-ENVIRONMENTAL DEVELOPMENT ... 128
5.1 Dating of Groundwater Using 14С ........................ 128
5.1.1 Radiocarbon in groundwater and the problems
of age dating .................................. 128
5.1.2 14C in groundwater of the Najd region - data
and corrections ................................ 130
5.1.3 Interpretation of l4C data in relation to the
carbon sources and the water origin ............ 136
5.1.4 Comparison of l4C data with data from other
sources ........................................ 142
5.2 Estimation of Paleo-Recharge Temperatures by Noble
Gas Thermometry ....................................... 143
5.2.1 Noble gases importance and types of
applications ................................... 143
5.2.2 Noble gases interpretations and evidence of
recharge ....................................... 145
5.3 Conclusion ............................................ 149
6 CHAPTER: NAJD GROUNDWATER SITUATION AND FUTURE
MANAGAMENT ................................................. 150
7 REFERENCES ................................................. 156
8 ANNEX ...................................................... 163
LIST OF FIGURES
1.1 Location of the Study Area in Dhofar with the proposed
agriculture sites (bold black) ............................. 5
2.1 Total rainfalls in Thumrait and Qeroon Hiritti stations
for the period (1977-2009) ................................ 10
2.2 Comparison between different wadis flow in each year ...... 12
2.3 Total monthly cumulative flows from four wadi Gauges
(1985-2008) ............................................... 13
2.4 Distribution of faults in the Study Area .................. 16
2.5 Simplified geological map of the Study Area and cross
sections locations ........................................ 18
2.6 Isopleths for the base of the upper UER in Najd area ...... 23
3.1 Schematic South-North (A-A) and West-East (B-B)
hydro-geological cross sections along the Study Area
(see Figure 2.5, directions) .............................. 29
3.2 Groundwater flow direction (arrows) in aquifer С .......... 35
3.3 Groundwater flow direction (arrows) in aquifer ............ 36
3.4 Variation in water level for aquifer A and В up to 2009 ... 39
3.5 Water level variations in Helat Ar Rakah (aquifer A) for
the period (1991-2008) .................................... 40
3.6 Water level variations in Hanfeet (aquifer B) for the
period (1992-2009) ........................................ 41
3.7 Variation in water level for aquifer С up to 2009 ......... 42
3.8 Water level variations in Helat Ar Rakah (JICA-6) and
Hanfeet (001/016) in aquifer С for the period
(1990-2009) ............................................... 43
3.9 Variation in water level for aquifer D up to 2009 ......... 45
3.10 Water levels variations in Hanfeet (aquifer D) for the
period (1992-2009) ........................................ 46
3.11 Locations of wadi gauges, boreholes responding with
flood events and wadi flow direction (dark arrows) ........ 48
3.12 Comparison between borehole Mathiral water level and
Wadi Ghadun flood event ................................... 49
3.13 Comparison between borehole KHT-A water level and Wadi
Thahboon flood events ..................................... 50
3.14 Monitoring well (001/007) in Shsir with some respond
related to flood events ................................... 51
3.15 Comparison between boreholes RBK-C and Ribkutl water
level and Wadi Thahboon flood events ...................... 53
4.1 Sampling locations from all aquifers ...................... 60
4.2 Overall dominant major ions in Najd groundwater ........... 69
4.3 Dominant major ions in different Najd aquifers ............ 69
4.4 Piper diagram from all groundwater samples of Najd area
including four developed hydrochemical facies ............. 70
4.5 Comparison between major ions in Najd aquifers ............ 71
4.6 Total dissolved solids (TDS) versus Na/Na+Cl .............. 72
4.7 Total dissolved solids (TDS) versus Mg/Mg+Ca .............. 72
4.8 Total dissolved solids (TDS) versus Ca/Ca+SO4 ratio ....... 73
4.9 Total dissolved solids (TDS) versus Cl/sum anions ratio ... 74
4.10 SO4 versus НСО3/sum anions ratio compared with rainfall
and sea water ............................................. 74
4.11 Earth's alkaline-alkaline ratio relative to the salt
forming (Cl/SO4 ratio in the Najd aquifers ................ 75
4.12 Fe versus As for different aquifers of Najd ............... 77
4.13 Fe versus В for aquifers A to D ........................... 77
4.14 As versus Cu for all aquifers ............................. 78
4.15 Saturation index in different aquifers versus Total
dissolved solids (TDS) .................................... 79
4.16 Aquifer matrix compositions in different aquifers ......... 83
4.17 Sulphur in aquifer matrix and sulphate in groundwater in
different aquifers ........................................ 85
4.18 Calcium and magnesium in aquifer matrix of Najd aquifers
based on X-RF analyses .................................... 86
4.19 Comparison of trace element in the matrix of different
aquifers .................................................. 87
4.20 δ2H-δ18O dia gram of groundwater, spring water, and
precipitation from the Dhofar region and the different
Najd aquifers (Najd Groundwater Line [NGL]: black line
bold); further: Northern Oman Meteoric Water Line
(NOMWL: dotted), Southern Meteoric Water Line (SOMWL:
dashed-dotted), Global Meteoric Water Line (GMWL) are
depicted for reference .................................... 89
4.21 Relation of S and О isotopes in groundwater sulphate
from the different aquifers ............................... 96
4.22 δ34Ssulphate VS δ13CDIC in groundwater of Najd aquifers ....... 98
4.23 δ34Ssulphate VS sulphate concentration in groundwater
from all aquifers ......................................... 98
4.24 Distribution of δ34Ssulphate in groundwater
of aquifer С and D ....................................... 102
4.25 Profiles constructed in different aquifers based on the
consistent relationship between hydrochemistry and
isotope data, for an example from each aquifer (see
Figure 4.26) ............................................. 106
4.26 (a-p) Characteristic profiles reporting the
hydrochemical and isotope development of the
groundwater in aquifers A to D. The profiles follow the
main directions of the groundwater flow: in aquifer
A (a, b = A) and aquifer В (с, d = В) south to north,
in aquifer С (e, h = C1, C2) ............................. 109
4.27 δ2H distribution in aquifer D and direction
of the recharge in dot line shows decrease of monsoon
influence along the flow line; high depletion of 2H
could also point to strong pumping activities because
of fossils water with depleted 2H ........................ 111
4.28 CI (mg.L-1) distribution in aquifer D and proposed
recharge direction in dot line ........................... 112
4.29 Sr versus F in aquifer A ................................. 116
4.30 Distribution of fluoride in aquifers С and D ............. 117
4.31 Total dissolved solids (TDS) versus Fluorite (SI) ........ 118
4.32 Electrical conductivity (μS.cm-1)
distributions in aquifers А, С and D ..................... 121
4.33 CI versus Br compared with sea water ..................... 123
4.34 Sodium Adsorption Ratio (SAR) from the different
aquifers ................................................. 126
5.1 Groundwater age in different aquifers .................... 136
5.2 Groundwater age in years BP from all aquifers using
Mod-1 with 13C (AMS) ..................................... 138
5.3 Groundwater age versus 14C concentration ................. 139
5.4 Comparisons between 13C and 14C showing three types of
influences, (14C values were plot in DIC and AMS for
each aquifer) ............................................ 140
5.5 18O of water versus l4C classified the
source of groundwater in Najd to three groups, (14C
values were plot in DIC and AMS for each aquifer) ........ 141
5.6 18O versus l3CDIC for different aquifers in Najd,
reflecting soil organic matter and mixing processes ...... 141
5.7 Ne/He versus 3Не4Не ratio in aquifers A to D as
evidently for influence of different inputs:
atmospheric and radiogenic ............................... 145
5.8 NGT versus 4He in aquifers A to D ........................ 146
5.9 Groundwater age in comparison with NGT for different
aquifers ................................................. 147
5.10 Groundwater age versus NGT in different aquifers ......... 148
LIST OF TABLES
2.1 Meteorological data collected from Thumrait station
during the period from 1986 to 2009 ....................... 11
2.2 Summary of the hydrogeological units in the Study Area
(after GRC, 2008) ......................................... 20
3.1 A summary of hydraulic characteristics from the Najd
aquifers (saturation zone) (modeled after GRC, 2008) ...... 31
3.2 Estimated recharge periods to reach aquifers based on
water level and flood events .............................. 48
4.1 Results of the hydrochemical analyses of groundwater and
precipitation in the Najd region .......................... 61
4.2 Correlation coefficient matrix water parameters for all
Najd aquifers ............................................. 64
4.3 Principle component varimax rotated factor analysis for
Najd water parameters (n=79) .............................. 66
4.4 Range of total dissolved solid (TDS) concentrations in
each aquifer .............................................. 68
4.5 Average of major ions concentration and their percentage
in each aquifer ........................................... 68
4.6 Saturation index (SI) of the groundwater .................. 80
4.7 (a-b) Lithological results for 9 boreholes in Najd
analyzed by using XRF ..................................... 82
4.8 Elements obtained from borehole WWD-25 by using (XRF)
analysis .................................................. 84
4.9 Minimum and maximum concentration of isotopes in each
aquifer ................................................... 88
4.10 Results of isotope analyses of water, sulphate, DIC and
tritium from water, in addition to 13C of lithology ....... 92
4.11 Enrichment factor for sulphate reduction (ε) along
selected directions ....................................... 99
4.12 The FAO standards for the safe upper limits of total
salts in water for stock in arid countries ................ 120
5.1 14C data and age calculations by different models ......... 132
5.2 Comparison between NGT, helium isotopes and groundwater
age ...................................................... 146
ANNEX
A-l Results of chemical data and precipitation collected in
2008 and 2009 (mg.L-1) ..................................... 163
A-2 Results of chemical analyses and precipitation collected
in 2008 and 2009 (meq.L-1) ................................. 167
A-3 Stable isotopes and tritium for groundwater and
precipitation analyses collected during 2008 and 2009 ..... 171
A-4 Results of trace elements and precipitation collected in
2008 ...................................................... 174
A-5 Results of noble gases collected in 2009 .................. 176
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