HYDROGEOCHEMICAL AND ISOTOPIC INVESTIGATIONS ON PHREATIC AQUIFERS OF URBAN AND PERI-URBAN CLUSTERS OF KOZHIKODE DISTRICT, KERALA, SOUTHERN INDIA. Ph.D. Thesis under the Faculty of Environmental Studies Cochin University of Science and Technology Submitted by Jesiya N P Research Scholar Geomatics Division Centre for Water Resources Development and Management Kunnamangalam, Kozhikode - 673571 Supervising Guide Dr. Girish Gopinath Research Supervisor Senior Scientist (On Lien) Geomatics Division Centre for Water Resources Development and Management (CWRDM) Centre for Water Resources Development and Management Kunnamangalam, Kozhikode - 673571 June 2019 DECLARATION I hereby declare that the work presented in the thesis entitled “HYDROGEOCHEMICAL AND ISOTOPIC INVESTIGATIONS ON PHREATIC AQUIFERS OF URBAN AND PERI-URBAN CLUSTERS OF KOZHIKODE DISTRICT, KERALA, SOUTHERN INDIA” has been carried out by me under the supervision of Dr. Girish Gopinath, Senior Scientist, Geomatics Division, Centre for Water Resources Development and Management, and further declare that this has not been submitted earlier in part or in whole to any University or Institute for the award of any degree or diploma. Jesiya N P Place: Kozhikode Date:19-06-209 Dedicated to My Beloved Parents ACKNOWLEDGMENTS Undertaking this PhD has been a truly life-changing experience for me and I take this opportunity to extend my sincere gratitude and appreciation to all those who have been lending their support and guidance all the while during my research period. It is with all sincerity and high regards that I express my heart felt gratitude to Dr. Girish Gopinath, Research Guide, Senior Scientist, Geomatics Division, Centre for Water Resources Development and Management, for his guidance, pertinent encouragement, inspiring discussions and valuable suggestions throughout this investigation. I express my gratefulness and sincere thanks to Dr. Anitha A. B, Executive Director, Centre for Water Resources Development and Management, for providing me the necessary facilities to carry out the research work apart from her inspiration throughout this investigation. I profoundly thank Dr. Dinesan V.P, Head, Geomatics Division, Centre for Water Resources Development and Management, for providing all the necessary facilities to complete the research work. I express my sincere thanks to Dr. Harikumar P S, Senior Principal Scientist & Registrar i/c, Head, Administration and Finance Division , Water Quality Division, CWRDM for providing laboratory facilities to carry out the water quality analyses. I am extremely grateful to Dr. Resmi T R, Scientist & Head i/c, Isotope Hydrology Division, CWRDM for her immense help rendered in data interpretation and guidance during the course of this work. I owe my hearty thanks to Dr. R D Deshpande, Scientist-SG and Chairman, Geosciences Division, Physical Research Laboratory, Ahmedabad, for providing laboratory facilities to carry out the stable isotope analysis. I wish to express my thanks to Ambili G K, Scientist, CWRDM, for her valuable and inspiring suggestions during the course of this work. I place on record my sincere gratitude to Dr. K.Ch.V Naga Kumar, Scientist B, Geomatics Division, CWRDM, for careful reading through the manuscript and inspiring suggestions during entire thesis preparation. I express my sincere thanks to Prof. (Dr.). Thrivikramji. K.P, Center for Environment and Development, Thiruvananthapuram, for his valuable suggestions in the preparation of the research work. I express my sincere thanks to the Regional Director, CGWB, Kerala, and Dr. K.M. Abdul Ashraf, Groundwater Department, Kerala for providing secondary data to carry out the research work. With much gratitude, I acknowledge the sincere co-operation and help rendered by Mrs. Bineesha T M (Technical Officer), Mr. Anil Kumar K S, Mr. Sreesarath K P and other research fellows, Geomatics Division, CWRDM for their invaluable co-operation in the time of need. It is my pleasant duty to express my gratefulness and sincere thanks to UGC-MANF, Gov. of India and Kerala State Council for Science, Technology and Environment (KSCSTE), Kerala, India for providing me the financial support to carried out the research work. Most importantly, I am immensely grateful to my beloved family especially my beloved husband Mr. Abdul Jaleel ,brother Mr. Abdul Jami, sister Mrs. Jahani Shaheer, Amina Nourin and my dearest son Ali Riza who provided me continuous inspiration and endless support for the completion of this task. With big thanks to my lord almighty for all these……….. Jesiya N P PREFACE Groundwater, being the largest freshwater resource to humankind, plays a vital role in sustenance and development of a society. The global dependency on water resources for various purposes like domestic, industrial and irrigational needs is rapidly increasing. The situation is likely to worsen further as demand for freshwater will increase in the future with increase in population. As groundwater forms an important component of the total water supply on earth, the aquifers are often under stress, resulting in lowering of the water table, reduction in well yield, well interference due to close spacing of wells, drying up of springs and wells, severe water quality deterioration and so on. The dynamics of groundwater resources is sensitive to recharge processes from aquifers, hence groundwater problems (qualitative and quantitative) are generally found to be more pronounced in urban environment along with variability in spatio-temporal precipitation patterns and intensification of extreme climate events. The overall objective of the study is hydrogeochemical and isotopic characterization of phreatic aquifers in two different urbanized environments viz. urban and peri-urban zones of Kozhikode District, Kerala. Evaluation of spatio-temporal variation of hydrogeochemical characteristics and inherent hydrogeochemical process of groundwater in phreatic aquifers of the urban and peri- urban clusters of the study area pointed out a distinct spatial variations exist between the groundwater of urban and peri-urban zones. Inter-ionic relationships and multivariate statistical analysis of hydrogeochemical parameters revealed that both urban and peri-urban phreatic aquifer geochemistry was controlled by silicate weathering and ion-exchange processes. The water quality of groundwater in majority of the wells in the urban and peri- urban regions were are within the permissible limits of BIS (2012) and WHO (2011) drinking water standards. A few wells in the urban alluvial phreatic aquifer showed influence of anthropogenic contamination indicated by the elevated concentration of nitrate and faecal contamination. The origin and recharge mechanism of groundwater in the study area were determined using stable isotope techniques. The analysis of the stable isotope ratios of hydrogen and oxygen of the different water bodies and of rainfall in the region showed that the southwest monsoon and northeast monsoon rains contributed significantly to the aquifer recharge. Point recharge estimation of rainwater contribution to the groundwater was done using isotope mass balance method and it was found that monsoon rains contributed 35% in the urban alluvial aquifers, up to 39% in the urban laterite aquifer and 42% in the peri-urban laterite aquifer. Spatio-temporal variation of groundwater quality aspects and Groundwater Quality Index was derived using Geographic Information System (GIS) based Multi Criteria Decision Making (MCDM) technique. Through this technique, the study area could be divided into four groundwater suitability zones for drinking purpose. Of the total urban area, 24%, 42%, 34% were categorized as highly suitable, suitable and moderate to poor groundwater suitable zone respectively, whereas 84%, 11% and 5% of the peri-urban zone were covered under highly suitable, suitable and moderate to poor groundwater suitable zones respectively. Hydrogeologic characteristics of phreatic aquifers, the high population density residing in the coastal plain, improper groundwater use pattern and influence of surface water resources like the Kallayi River and Cannoli canal may together imparted the moderate to poor quality status of the study area. Geospatial analysis endowed an efficient platform for linking different environments (urban and rural continuum), different hydrogeological and environmental factors. Groundwater vulnerability and groundwater potential analysis carried out using customized GIS based Fuzzy-Analytic Hierarchy Process (FAHP) technique and the spatial data thus obtained act as an essential dimensions for monitoring and planning the changing urban and peri-urban spatial environment. The analysis pointed out that majority of the highly potential groundwater zones of the urban cluster were vulnerable to contamination due to intense anthropogenic activities. Validation analysis of groundwater vulnerability and groundwater potential zones revealed that remote sensing and GIS based approach is a powerful decision making tool for sustainable water management in urban and peri-urban environment.. CONTENTS Page No Chapter 1. INTRODUCTION 1 1.1. General introduction 1.2. Review of literature 5 1.3. Environmental settings 25 1.3.1. Regional geology 29 1.3.2. Landuse/landcover statistics 31 1.3.3. Rainfall and other meteorological parameters 33 1.4. Relevance of the study 34 1.5. Objectives 36 Chapter 2. MATERIALS AND METHODS 2.1. Primary data collection 38 2.1.1. Field investigations 38 2.1.1.1. Identification and description