ENVIRONMENTAL MANAGEMENT OF WATERLOGGING PROBLEM IN SOUTH-WEST COASTAL REGION OF BANGLADESH SYED MOHAMMED TAREQ MASTER OF SCIENCE IN ENGINEERING (CIVIL & ENVIRONMENTAL) Department of Civil Engineering BANGLADESH UNIVERSITY OF ENGINEERING AND TECHNOLOGY January 2016 i Environmental Management of Waterlogging Problem in South-West Coastal Region of Bangladesh A Thesis Submitted by SYED MOHAMMED TAREQ (Roll No: 1009042104) In partial fulfillment of the requirement for the degree of Master of Science in Engineering (Civil & Environmental) Department of Civil Engineering BANGLADESH UNIVERSITY OF ENGINEERING AND TECHNOLOGY January 2016 ii iii iv Dedicated to To all those vulnerable people of south-west coastal region of Bangladesh, who have been overcoming the environmental challenges with a dream of better tomorrow. v ACKNOWLEDGEMENT At the very beginning, I would like to show my gratitude towards Almighty, who has given me the opportunity to do a research in one of the hardest hit region induced by climate change. I would like to enunciate my heartfelt and intense gratefulness to my supervisor Prof Dr Muhammad Ashraf Ali, Department of Civil Engineering, BUET, whose generous guidance, attention and particularly unwavering encouragement always steered my bewildered thoughts in right direction. The door to Prof. Ashraf office was always open, whenever I ran into a trouble spot or had a question about my research or writing. I would like to thank all local people in the study area who gave me their valuable time and effort during Focus Group Discussion (FGD), Key Informant Interview (KII) and questionnaire survey as well as support in every step in the study area during the field survey. I need to express my sincere appreciation and gratitude to A.Z.M Zahedul Islam, Chief Scientific Officer, Bangladesh Space Research and Remote Sensing Organization (SPARRSO), for his teaching on satellite image as well as guidance to the research paper. I cannot but give special thanks to Uttaran, a Non-Government Organization (NGO) working in the coastal belt for their selfless cooperation. I am grateful to Dr. A.B.M. Badruzzaman, Professor CE Dept., BUET, Dr. Md. Tauhid Ur Rahman, Professor CE Dept., MIST, Khaza Minnatullah, Ex Environment Specialist of World Bank and all other teachers for their cordial encouragement and valuable suggestion at different stages of conducting this study. Many organizations have extended their support, provided encouragement and critical insights that finally lead to the completion of this work. I am personally indebted to all of them. Special thanks would go to SPARRSO, Climate Change Laboratory at MIST (under HEQEP), Center for Environmental and Geographical Information Services (CEGIS), Institute of Water Modelling (IWM), Bangladesh Water Development Board (BWDB), Bangladesh Rural Advancement Committee (BRAC), Department of Agriculture, Department of Fisheries and many others of faces and library for providing valuable information, materials and necessary data. I would like to give special thanks to Md. Ismail, Librarian of IWFM (Institute of Water and Flood Management) library for whole hearted support. Finally, I would like to express my deep appreciation to the permanent inspiration and enthusiasm provided by my wife Dr. (Lt Col) Shamima Yasmin, during the study. vi ABSTRACT The south-west coastal region of Bangladesh has been very fertile and rich in biodiversity, and people had their own indigenous sediment management system. However, construction of polders, which started in early 60’s, led to the present waterlogging crisis. The compartmentalized polder system delinked flood plains from rivers. Sedimentation took place only in river channel, raising river beds; water remains trapped in beels, turning these into water logged area. Waterlogging hazard is a burning issue for Jessore, Khulna and Satkhira, the three coastal districts of the southwest region of Bangladesh. This study presents an assessment of the waterlogging problem and its impact on the coastal region, with a particular focus on Tala Upazila, Satkhira District. In this Upazila, there was no significant waterlogging in the past, as evident from satellite images of 1989. The fertile land started going under water gradually and after the massive rainfall of 2011 as much as 34 % agricultural land of the study area disappeared under waterlogging. There was a reasonable fresh water flow in Kabodak River in the past, as evident from the satellite images of 1999 and 2000. However, due to huge sediment deposition, Kabodak has lost its water carrying capacity. It has significantly affected local biodiversity in the area. Most of the farmers have turned into fisherman. Salinity of both groundwater and surface water in the study area is increasing with time. Many tube wells have become unusable due to high salinity. Local people are fighting the situation through innovative adaptation, particularly in the area of agriculture (e.g., floating agriculture). This problem might be mitigated through implementation of Tidal River Management (TRM), utilizing local knowledge and their involvement. TRM operation should be continuous and a list of successive tidal basins were proposed for future implementation. Excavation of the dead rivers as well as loop cut will drain out logged water to the downstream during rainy season and renew its normal tidal nature. vii LIST OF CONTENTS ACKNOWLEDGEMENT .................................................................................................... vi ABSTRACT ....................................................................................................................... vii LIST OF TABLES ............................................................................................................... xi LIST OF FIGURES ............................................................................................................ xii ACRONYMS AND ABBREVIATIONS ............................................................................ xv CHAPTER 1 ......................................................................................................................... 1 INTRODUCTION ................................................................................................................ 1 1.1 Background ............................................................................................................. 1 1.2 Objectives ............................................................................................................... 2 1.3 Outline of Methodology .......................................................................................... 2 1.4 Organization of the Thesis ...................................................................................... 3 CHAPTER 2 ......................................................................................................................... 4 LITERATURE REVIEW ...................................................................................................... 4 2.1 Introduction ............................................................................................................ 4 2.2 Bangladesh: A Geographical Introduction ............................................................... 4 2.3 Description of the Study Area ................................................................................. 6 2.3.1 Climate of the Area .......................................................................................... 6 2.3.2 Rivers of the Study Area .................................................................................. 7 2.3.3 Geology of the Study Area ............................................................................... 7 2.3.4 Physiography of the Area ................................................................................. 8 2.3.5 Catchment Wise Area ...................................................................................... 9 2.4 Delta Dynamics over Time and Space ................................................................... 12 2.5 History of Water Management .............................................................................. 15 2.5.1 Colonial Period .............................................................................................. 15 2.5.2 Water Management after 1950 ....................................................................... 15 2.5.3 Shift to Small Scale Projects and People’s Participation ................................. 15 2.6 “Dying” Rivers in the Southwest Delta ................................................................. 16 2.7 The Coastal Embankment Project (CEP) ............................................................... 18 2.8 Flood versus Water Logging ................................................................................. 20 2.9 The “discovery” of “Tidal River Management (TRM)” ......................................... 21 2.10 Waterlogging Scenario from Previous Studies ................................................... 22 2.11 Case Studies ...................................................................................................... 25 2.11.1 Khulna-Jessore Drainage Rehabilitation Project ............................................. 25 2.11.2 Beel Dakatia, 1990 ......................................................................................... 25 2.11.3 Beel Bhaina tidal basin, October 1997 – December 2001 ............................... 26 viii 2.11.4 Beel Kedaria, January 2002 – January 2005 ..................................................