Finally, the Supreme consciousness enlightened me in the journey of knowledge and made to complete the work successfully. Gopakumar C.

Transcription

1 ACKNOWLEDGEMENTS I would like to express my immense gratitude to my esteemed research Supervisor Dr.GSLHV Prasada Rao, Associate Director of Research and Professor of Agricultural Meteorology, Kerala Agricultural University, Vellanikkara, Thrissur for his expert guidance, constant encouragement and valuable suggestions for excellence throughout the course of this study. I would like record my sincere gratitude to Dr.H.S.Ram Mohan, my Co-Supervising Guide, Professor of Meteorology and Director, School of Marine Sciences (Retd.), Cochin University of Science and Technology (CUSAT), Kochi for his generous support, constant encouragement, constructive guidance and inspired suggestions throughout the study period, without which the thesis could not have been completed. My sincere thanks go to AICRP on Agrometeorology, Central Research Institute for Dryland Agriculture (CRIDA), Hyderabad for financial support to AICRAM at Thrissur Centre, which made this study possible. I am thankful to the Registrar, Kerala Agricultural University, Vellanikkara, Thrissur for granting me No Objection Certificate for carrying out the research work as a part-time student of CUSAT. Thanks are also due to the Special Officer, Academy of Climate Change Education and Research (ACCER), Kerala Agricultural University, Vellanikkara, Thrissur for providing excellent computing facility and working environment. I express my sincere thanks to Dr.K.R.Santosh, Head of the Department and my Doctoral Committee Member, Department of Atmospheric Sciences (DAS), Cochin University of Science and Technology, for providing me necessary facilities during the course of my doctoral work. I express my gratitude to Dr.A.V.R Keasava Rao, Scientist, International Crops Research Institute for Semi Arid Tropics (ICRISAT), Hyderabad for his various technical help and encouragement during the study period. I am indebted to Dr.C.A.Babu, Professor, and Department of Atmospheric Sciences for inspiration and suggestions during the study period. My sincere thanks are due to Dr.Venu G Nair, Lecturer, DAS, CUSAT for his generous help at all times of need in CUSAT during my doctoral study period. My special thanks go to Sri.KN Krishnakumar, Research Associate and my fellow worker at ACCER for

2 valuable discussions during the course of study. N.Manikandan, Research Associate, Agromet Data Bank, CRIDA, Hyderabad and Sri.N.Manikandan, Research Scholar, Agro Climate Research Centre (ACRC), Tamil Nadu Agricultural University (TNAU), Coimbatore have helped me in various ways during the course of this work. My sincere thanks are due to them. I sincerely acknowledge the services rendered by Sri. Unnikrishnan Thekkepat for statistical analysis of weather crops data. I would like to express my special thanks to Dr. B. Ajith Kumar and Smt.Lincy Davis, Assistant Professors, Dept. of Agricultural Meteorology, College of Horticulture, Vellanikkara for their cooperation and encouragement. My special thanks are due to Sri.P.M.Paulose, Sri.V.N.Gopi, Sri.T.P.Gangadharan, Smt.Mini Sathish, Smt.Leelamani, Sri.T.V.Saju, Sri.Sunil and Sri.A.K.Azad, my colleagues at ACCER, KAU for their constant encouragement and support. The office and the technical staff at the Department of Atmospheric Sciences, CUSAT, and Kochi have always been very helpful during the course of this work. I would like to express my sincere thanks to all of them. The thesis could not have been completed, but for the patience and understanding of my better half Smt.Deepa and my beloved son Navaneeth. I thank them for being with me at all times of need during the course of my study. The encouragement and support from my brothers were immense during the course of work. I am deeply indebted to my beloved mother and mother-in-law for their wholehearted blessings. Finally, the Supreme consciousness enlightened me in the journey of knowledge and made to complete the work successfully. Gopakumar C.S

3 CONTENTS Title Page. Declaration Certificate.. Acknowledgments... Contents List of Figures... List of Plates. List of Tables Chapter 1: Introduction i ii iii iv vi xi xvi xvii 1.1 Global climate change scenario Climate change scenario in India Climate change scenario in Kerala. 8 Chapter 2 : Review of Literature 2.1 Temperature variability Rainfall variability Climate change over Kerala Temperature Rainfall Climate variability and food security Crop weather relationships Tea Coffee Black pepper Cardamom Cocoa Cashew Rubber 51 Chapter 3 : Data and Methodology 3.1 Climatic data over India Climatic data over Kerala Rainfall Potential evapotranspiration (PET) Water balance studies Climate variability and food security.. 60

4 3.7 Climate variability and plantations across the highranges Cocoa Cashew Rubber. 64 Chapter 4 : Regional Climate change 4.1 Temperature trends over India Temperature projections Rainfall trends over India Maximum Temperature trends across Kerala Coastal zone (Lowlands) Midlands Highranges Minimum temperature trends across the State Coastal zones Midlands Highranges Mean temperature trends across the State Coastal zone Midlands Highranges Trend in temperature range across the State Coastal zone Midlands Highranges Onset of monsoon Annual rainfall Southwest monsoon Post monsoon Winter Summer Decadal and tri-decadal trends in rainfall across Kerala Climate shifts over Kerala Occurrence of climatological droughts over Kerala.. 94 Chapter 5: Climate variability and food security 5.1 Impact of drought on Indian foodgrains production.. 98

5 5.2 Climate change impacts on Indian foodgrains production Change in cropping pattern across Kerala Trend in area, production and productivity of paddy in Kerala Impact of heavy rainfall on paddy production in Kerala Effect of unusual summer showers on paddy production in 115 Kerala during Effect of monsoon uncertainties on rice production during Effect of prolonged rains during 2010 on rice production Impact of Climate change on rice production in Kerala Impact of soil degradation on rice productivity Climate variability and food price 130 Chapter 6: Climate variability and plantations across the highranges 6.1 Rainfall distribution Rainfall trends Thermal regime Temperature Trends Moisture regime Trend in climate shifts Trends in area and production of plantations Cardamom Tea Coffee Black pepper Climate variability and plantation crops production Annual rainfall versus plantations Rainfall and tea Rainfall and coffee Effect of blossom and backing showers on coffee production Rainfall and black pepper Effect of rainfall on the pepper production in Wayanad District Rainfall and cardamom Temperature and plantations Temperature and tea Temperature and coffee Temperature and black pepper Temperature and cardamom. 166

6 6.7.5 Heat units and plantations Tea Coffee Black pepper Cardamom Water deficit during summer and plantations Weather abnormalities and yield Rise in maximum temperature during January-March, 2004 in Wayanad and its impact on black pepper Climate variability and climate change impacts. 175 Chapter 7: Climate variability and cocoa production in Kerala 7.1 Trends in area, production and productivity of cocoa in Kerala Trends in decadal area, production and productivity Rainfall regimes over Kerala Rainfall trends Thermal regimes Temperature trends during the study period Rainfall versus cocoa yield Soil moisture versus yield at Vellanikkara Yield variation in good and bad years in different clones of cocoa Annual temperature and cocoa yield in Kerala Summer maximum temperature and yield Heat Unit (GDD) and yield Temperature and cocoa yield at Vellanikkara Effect of high summer maximum temperature on cocoa yield at Vellanikkara Heat Unit (GDD) and cocoa yield at Vellanikkara Water deficit and yield Climate variability and cocoa yield. 200 Chapter 8: Climate variability and cashew production in Kerala 8.1 Area, production and productivity of cashew in India Area, production and productivity of cashew in Kerala Cashew growing environment Rainfall regimes of cashew Thermal regimes of cashew Effect of latitude and altitude on flowering of cashew in Kerala Flowering and latitude.. 214

7 8.7 Rainfall and cashew productivity Temperature and yield in cashew Yield forecasting of cashew Drought and cashew productivity Environmental constraints over Kerala Effect of strong easterly wind on cashew production across the Central Kerala Climate variability and cashew 226 Chapter 9: Climate variability and Rubber production in Kerala 9.1 Trend in area, production and productivity Rainfall regimes of rubber Thermal regime of rubber Climate variability and rubber production Climate change impacts on rubber Chapter 10: Summary and conclusions Conclusions and recommendations 247 References Appendix