ABSTRACT
This paper examines the hydrochemical facies of groundwater present in the shallow marine Plain Sands aquifer of Udi and its immediate environs, maps their areal distribution and attempts to explain the controlling processes responsible for the various facies. 12 water samples were collected from wells tapping the shallow marine Plain Sands aquifer of Udi and environs and analyzed for various parameters including pH, total dissolved solids (TDS), K, Na, Ca, Mg, Cl, NO3, Fe, Pb, TH, Acidity, EC, HCO3 and SO4 after standard procedures. The data obtained were subjected to R-mode factor analysis. Four factors were extracted. Factor 1 includes TDS, Ca, Cl, NO3, HCO3, Fe, TH, and EC reflects the signature of the pollution factor resulting from seepages into the aquifer of water from the tide-influenced Ajali River and Ama Brewery pollution factor. Factor 2 has high loading values of Mg, NO3 and K and represents the processes of natural rainwater recharge and water-soil/rock interaction. Factor 3 includes SO4 and can be related to the dissolution of sulphides from interstratified peat within the geological formation, heavy vehicular activity and the brewery process in the town. A broad zone of groundwater interaction (mixing) between water species represented by factors 1 and 2 is thus created towards the riverbanks. The implication of this is that ionic concentration in the water decreases away from the banks of the river an indication that the quality of groundwater improves away from the river. Factor 3 is enhanced in the southeastern portion of the town where it is deemed to be caused by the dissolution by groundwater of sulphur bearing minerals within the geological Formation, and also in the central and northwestern portions of the town were it could be related to the rain-dissolution of sulphur bearing compounds from gaseous emanations arising from vehicles and the brewery industrial process respectively, which eventually, as acid-rain recharges aquifers in the vicinity. This paper demonstrates the effectiveness of factor analysis in evaluating hydrochemical processes in Swamp and industrial areas
TABLE OF CONTENTS
TITLE PAGEI
APPROVAL PAGEII
DEDICATION III
ACKNOWLEDGEMENT IV
ABSTRACTS V
TABLE OF CONTENTSVII
LIST OF FIGURESX
LIST OF TABLES XI
LIST OF PLATESxii
CHAPTER ONE: INTRODUCTION1
1.1 Locations and extent1
1.2 Geography2
1.2.1 Vegetation2
1.2.2 Mangrove Swamp Forest2
1.2.3 Tropical Rain Forest3
1.2.4 Derived Savanna Woodland3
1.2.5 Soil4
1.3 Literature Review4
1.4 Objectives of the Study8
1.5 Study Methodology8
1.5.1 Preliminary studies8
1.5.2 Field Study9
1.5.3 Laboratory Analysis9
CHAPTER TWO: GEOLOGIC SETTING11
2.1 Regional Geography11
2.1.1 Topography 11
2.1.2 Drainage11
2.1.3 Climate 12
2.1.4 Vegetation14
2.2 Regional Tectonic Setting15
2.3 Regional Stratigraphy16
CHAPTER THREE: LITHOSTRATIGRAPHY22
3.1 Description of Lithologic units22
3.1.1. The Cross-Bedded Sandstone Units24
3.1.2 Laminated/Cross-Bedded Sandstone Unit (Ogba-cave)25
3.1.3 The Sandstone Unit (Ogwogwo Spring)26
3.1.4. The Shale Unit27
3.1.5 Friable Sandstone Units28
3.2 Sedimentary Structure30
3.2.1. Cross-Bedding30
3.2.2 Lamination30
3.2.3 Biogenic Structure31
3.2.4 Gully Erosion31
3.2.5. Waterfall and Cataract
3.2.6. Springs
3.2.7 Stalactite34
3.3 Sand sieve analysis35
3.3.1 Methodology36
3.3.2 Textural parameters37
3.3.2.1 Phi scale:37
3.3.2.2 Mean size (mz)37 37
3.3.2.3 Sorting ()38
3.3.2.4 Skewness (ski) 38
3.3.2.5 Kurtosis (kg)39 39
3.4 Results39
3.4.1 Cumulative curve with a probability ordinate39
3.4.2 Histogram of the Textural Analysis 43
3.5 Interpretation from textural analysis44
CHAPTER FOUR: HYDROGEOLOGY AND HYDROGEOCHEMISTRY46
4.1 Surface water hydrology48
4.1.1 Precipitation48
4.1.2 Runoff/Evapotranspiration49
4.2 Groundwater hydrology and aquifer systems51
4.3 Aquifer parameters52
4.3.1. Hydraulic conductivity (K)52
4.3.2 Transmissivity53
4.4 Hydrogeochemistry 55
4.4.1 Physical Analysis56
4.4.2 Biological Analysis56
4.4.3. Chemical analysis57
4.5 Graphical Methods 57
CHAPTER FIVE: MULTIVARIATE STATISTICS TECHNIQUES65
5.1 Review of multivariate statistical techniques65
5.1.1 Factor analysis65
5.2 Materials and methods67
5.2.1 Sampling and Analytical Procedures67
5.2.2 Data Treatment and Chemometric Analysis68
5.3 Results and Discussion73
5.3.1 Factor analysis73
5.3.2 Water Quality Index (WQI)76
CHAPTER SIX: SUMMARY, CONCLUSION AND RECOMMENDATION79
REFERENCE81
APPENDICES85
LIST OF FIGURES
LIST OF TABLES
LIST OF PLATES