A Study on the Possible Impacts of Climate Change on Food Security in the Central Coastal Area of Bangladesh Zubyda Siddika University of Wollongong
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University of Wollongong Research Online University of Wollongong Thesis Collection University of Wollongong Thesis Collections 2013 A study on the possible impacts of climate change on food security in the central coastal area of Bangladesh Zubyda Siddika University of Wollongong Recommended Citation Siddika, Zubyda, A study on the possible impacts of climate change on food security in the central coastal area of Bangladesh, Master of Environmental Science - Research thesis, School of Earth and Environmental Sciences, University of Wollongong, 2013. http://ro.uow.edu.au/theses/3966 Research Online is the open access institutional repository for the University of Wollongong. For further information contact the UOW Library: [email protected] A Study on the Possible Impacts of Climate Change on Food Security in the Central Coastal Area of Bangladesh Master’s Thesis Submitted in partial fulfillment of the requirements for the award of the degree of Master of Environmental Science (Research) By Zubyda Siddika School of Earth and Environmental Science University of Wollongong, NSW, Australia February 2013 i CANDIDATE’S DECLARATION I, hereby, certify that the work presented in this entitled “A Study on the Possible Impacts of Climate Change on Food Security in the Central Coastal Area of Bangladesh” for the award of the degree of Masters’ of Environmental Science ( Research), is an authentic record of my work carried out during the period March 2009 to February2013 under the supervision of Professor John Morrison, School of Earth and Environmental Sciences, University of Wollongong, Australia. The material presented in this thesis has not been submitted by me for any other award or degree. By Zubyda Siddika Candidate Signature Date: 25th of March,2013 ii ABSTRACT Global and local climate changes can affect crop yields in the future. Recent increase of weather related stresses and damages are resulting from an increase in the frequency of climate hazards. However, agriculture in both developing and developed countries depends highly on climate factors (temperature, solar radiation and precipitation) that act as a main driver of rice production. Nevertheless, the relationship of climate variability and rice production could vary in different regions across the world. Bangladesh is perhaps one of the most climatic vulnerable countries because of geographical location and large Gnga-Meghna-Brahmuptra river systems. The costal belt of Bangladesh covers 30% of the total agricultural land in Bangladesh, and plays an important role in the country’s GDP. The close dynamic relationship between climate variability and rice yield could be useful to identify yield losses or gains at different spatial scales. This relationship can have differences in their patterns as well as in magnitude at different spatial and temporal scales. This study consisted of a review of climate change issues for Bangladesh, an analysis of crop yield variations over the years 1990-2008 and some preliminary modeling of rice yields with changing climate parameters. Generally, three seasonal rice crops(Aman, Aus and Boro) have been cultivated in the study area. Based on correlation analysis, for the country’s central coastal belt, no or negative relationships have been indentified between climate parameters and yield. Although there are significant uncertainties in the predicted climate parameters, DSSAT 4.5 crop simulation model is an effective tool to show the potential impacts of predicted climate change on yields. For deriving DSSAT4.5 simulation model, climate parameters and management inputs is important to predict yield under the basis of planting period investigation. Model results indicate that as climate parameters like temperature increase, farmers could get lower yields in their cropping systems. Lower yields were estimated for the heavy rainfall period when plants could be washed away plant after planting. A 2˚C rise in minimum temperature will lead to a lowering of yields of around 800 to 1000 Kg/hectare in every seasonal rice crops in the study area. As a result, changing climate parameters in the central coastal belt area of Bangladesh could lead to lower yields in every rice season. Any lowering of yields due to climate change is important for the densely populated coastal belt area in Bangladesh as this could result in food insecurity for the region. iii ACKNOWLEDGEMENTS I would like to express my respect and gratitude to my supervisor Professor John Morrison, Department of Environmental Science, Wollongong University, Australia for his keen interest, guidance, patience and assistance throughout this research work. My special thanks to Kh. Shamsul Hoque SRDI, Dhaka for giving me rice datasets from 1990 to 2008. My special thanks also to Md. Abeed Hossain Chowdhury,Director of Computer & GIS Unit in Bangladesh Agricultural Research Council for providing me weather data. I am also thankful to Fahmida Akhtar, Senior Scientific Officer at WARPO who managed and organized weather datasets from their statistics in WARPO record. I also thankful to Dr. Paul Wilkens ,Scientist, Research and Market Development Division (IFDC), An international Centre for Soil and Agricultural Development for assisting and developing DSSAT weather file and giving me guidance to go up with DSSAT 4.5 modeling system. I am highly thankful to all of my friends and surrounding people who assist and encourage me to complete this research. iv Contents Name of the Contents Page Numbers CANDIDATE’S DECLARATION II ABSTRACT III ACKNOWLEDGEMENTS IV CONTENTS V LIST OF TABLES X LIST OF FIGURES XIII ACRONYMS XVI Chapter 1 – Introduction 1 1.1: Introduction 1 1.2. Background to the study 5 1.2.1 Bangladesh coast: The worst victim to natural disaster 7 1.2.1.1. Salinity & water logging 8 1.2.1.2. Ingress of soil salinity 9 1.2.1.3. Flood & water logging 10 1.2.1.4. Intrusion of saline water 11 1.2.1.5. Cyclones and the Bangladesh coast 12 1.2.1.6. Coastal erosion 14 1.3. Objective of the study 15 v Chapter 2: Literature review 16 2.1. Introduction 16 2.2. Objective of the review 19 2.3. Climate variability and rice production 2.4. The relationship between climate variability and rice production 19 2.4.1. Global changes in climatic parameters 20 2.4.2. Global changes in crop production parameters and their relationships to climatic condition 23 2.5. Projected climate change scenarios over the Indian Subcontinents 27 2.5.1. Projected future climate change scenarios over the Indian Sub-continent 33 2.5.2. Variability of crop production 34 2.6. Severity of Impacts of Climate change in Bangladesh 37 2.6.1. Climate vulnerability in coastal belt area of Bangladesh 39 2.6.2. Cropping pattern in coastal area of Bangladesh 40 2.6.3. Climate change affects the coastal area of Bangladesh 42 2.6.4. Relationship between temperature rise, rainfall, sea level rise and rice production in coastal areas of Bangladesh 48 2.7. Uncertainty of the model results 55 2.8. Discussion & Conclusions 57 Chapter 3: Study Area and Methods 60 3.1. Introduction 60 vi 3.2. Salient feature of the study area 60 3.3. Topography & landscape in the study area 62 3.4. Geology 64 3.5. Hydrology 65 3.6. Factors affecting for choosing the study area 66 3.6.1. Agriculture based Economic condition 66 3.6.1.1 Agriculture & cropping pattern in the study area 67 3.6.2. Climate dependent agriculture system 70 3.6.2.1. Impacts of rainfall on crop production 70 3.6.2.2. Impacts of temperature on crop production 71 3.7. Factors affecting rice production in the study area 72 3.7.1. Climatic factors 72 3.7.2. Water logging & embankment difficulties 73 3.7.3. Salinity intrusion 74 3.7.4. Farmer’s observations 74 3.7.5. Other factors 78 3.7.5.1. Yield gap 78 3.7.5.2. Economic factors 79 3.7.5.3. Opportunities for farmers to access quality seed 79 3.7.6: High risk of natural disaster in the study area 80 3.8. Methods 82 3.8.1. Literature review 82 3.8.2. Data Collection 82 vii 3.8.3. Data analysis 82 3.8.3.1. Statistical analysis 82 3.8.3.2. Synthesis of crop production data 83 3.8.3.3. Description of each seasonal cropping pattern 83 3.8.4. DSSAT 4.5 simulation model 84 3.8.4.1. Collect minimum datasets 84 3.8.4.2. Building the weather mean and running simulation model 84 Chapter 4: Results and Discussions 91 4.1. Introduction 91 4.2. Rice production 91 4.2.1. Seasonal impacts of climate parameters on rice production 92 4.2.1.1. Season 1: Aus rice productions 92 4.2.1.2. Season 2: Aman rice production 97 4.2.1.3. Season 3: Boro rice production 102 4.3.1. Simulation crop growth model 108 4.3.2. Method of simulation 108 4.3.2.1. Selection of rice variety 109 4.3.2.2.Crop Management Data 109 4.3.2.3. Description of soil input 110 4.3.2.4. Weather mean data 110 viii 4.3.2.5. Simulation Runs 111 4.3. 3.Simulation results 111 4.3.3.1. Outcomes based on actual observed data 112 4.3.3.1.1. Potential Aman and Aus rice yields 112 4.3.3.2. Outcomes based on modeling with an increase in minimum temperature of 2°C 113 4.3.3.2.1. Potential Aman and Aus yields under conditions of increased minimum temperature 113 4.3.4. Discussion of the modeling result 115 4.4. General discussion of the results 116 Chapter 5: Conclusions and Recommendations 119 5.1. Conclusions 119 5.2.