A Study of Vulnerability to Flash Flooding in Urban Wadi Hadhramaut, Yemen
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Durham E-Theses From damage to disaster: a study of vulnerability to ash ooding in urban Wadi Hadhramaut, Yemen. Buchanan, Polly Kathleen How to cite: Buchanan, Polly Kathleen (1998) From damage to disaster: a study of vulnerability to ash ooding in urban Wadi Hadhramaut, Yemen., Durham theses, Durham University. Available at Durham E-Theses Online: http://etheses.dur.ac.uk/5025/ Use policy The full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that: • a full bibliographic reference is made to the original source • a link is made to the metadata record in Durham E-Theses • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders. Please consult the full Durham E-Theses policy for further details. Academic Support Oce, Durham University, University Oce, Old Elvet, Durham DH1 3HP e-mail: [email protected] Tel: +44 0191 334 6107 http://etheses.dur.ac.uk 2 From Damage to Disaster: A study of vulnerability to flash flooding in urban Wadi Hadhramaut, Yemen. The copyright of this thesis rests with the author. No quotation from it should be published widiout the written consent of the author and information derived from it should be acknowledged. Polly Kathleen Buchanan MA by Research University of Durham Centre for Middle Eastern and Islamic Studies 1998 = I DEC 1998 Abstract This research is a study of the changing vulnerability of three towns in the Wadi Hadhramaut, Yemen, to flash flooding. The predominant construction material of the towns, Sei5ain, Shibam and Tarim, is the sun-dried mud-brick, a seemingly impractical choice in an area where floods are expected annually. However, until recently, the vulnerabiUty of the towns to flooding has been limited. The majority of the flood events in the Wadi Hadhramaut have caused Uttle destruction within the towns, the damage being manifested in the collapse of a few houses. Reconstruction of damage caused by flooding has remained within the capabiUty of the communities. Until recently, the protection of the towns has been through the practice of building on the raised ground beneath the mountains and on islands of coUuvial material defined by channels on the flood plain. Weirs and channels in the wadi bed guide and disperse the flood waters so that their destructive effect is reduced. Mitigation has been provided by aspects of house construction, and traditions of co-operation within the coromunities. Unfortunately, as a result of the rapid and erratic process of urbanisation, the towns are becoming increasingly vulnerable to flash floods. The town planning principles of building on high groimd and controlling flood waters have been affected by the pressing need to find more land on which to house the growing population. House construction has taken place at the edges of the flood channels. Agricultural lands that once absorbed flood waters have been developed into residential areas. Large suburbs have been developed in areas prone to inundation during major floods. These trends, coupled with the disruption caused by government intervention in community co-operation, have substantially increased the likelihood of a major flash flood causing a disaster in any one of these three towns. Acknowledgements: I would like to dedicate this project to my parents, George and Elizabeth. I also would like to take this opportunity to thank the many people who have given me vEiluable assistance during the course of my research. Many thanks are due to Professor E. Anderson for his patience and criticism. I am also very grateful for the support and practical assistance of Dr. J. Watson, Dr. E. Murphy, Dr. G. Boughton, Professor T. Niblock, Professor T. Burt, and Dr. A. Kirk. I would like to thank Professors luayton and SilUtoe for permission to attend lectures and seminars in tlie Department of Anthropology. I am also thankful for the encouragement of the employees of the Middle East and A&ica Desks, and grateful to the Yemen office of Oxfam for the opportunity to accompany them on a field trip to Shabwa. I have also benefited firom the generosity of Mrs E Welch, Miss L Buchanan, Mrs C. Buchanan, and the Council Fund for Students Travelling Abroad. Thank you all very much. I am extremely grateful to all those in Yemen who provided me with information and their opinions, trusting me to use them well. I have taken what they have given me and formed my own opinion. If there is to be any criticism of this work, it should fall at my feet rather than at theirs. If there be praise, then let it be for them for they sacrificed time, energy and sometimes their reputations to talk with me. I would, in particular, like to thank 'Omar al-'Aamery, Hassan BaaHashwaan, °Ali al-BaHbuuH, 'Abd al-Baary BaaRaJaa', and Atheer Najm. I am also appreciative of the permission given to me to root around in the hbraries of UNDP and The World Bank in SanaV. Finjdly, I would Uke to thank my firiends, in particular all those with whom I have hved. Their kindness, compassion and exceptional generosity have been very much appreciated. Table of Contents: Abstract: i Acknowledgements: ii Table of Contents: iii-iv Table of Tables: v List of Figures: vi List of Plates: vi Glossary: vii-xi Declaration: xii Introduction: 1-5 Methodology: 6-12 Difficulties encountered: 8 Research methods: 10 Chapter 2, Social and Political Backgroimd: 13-24 United Yemen: 17 Hadhramaut: 19 Chapter 3, Flooding in the Wadi Hadhramaut: 24-44 Rainfall: 24 Topography: 27 Flooding: 28 Flood summary: 33 Chapter 4, The Hadhrami house: 45-58 Construction methods: 46 Sun-dried mud bricks: 47 The fovmdations: 48 The walls: 50 Nuura: Ume plaster: 54 Flood protection and mitigation in house construction: 56 Foundations: prevention: 57 dikka-dikkuk: protections: 59 Lime wash protection: 60 Slow to fall: 61 Low cost: 62 Cement houses: 63 Chapter 5, Town planning and Flood Avoidance: 69- 81 Town planning heritage: 69 Avoidance: 71 Flood dispersal networks: 72 The Muuza': 75 Chapter 6, Traditions, Prevention and Mitigation: 82-101 Local Knowledge and Experience: 82 Co-operation and Preparation: 88 Celebration: 89 Of universal benefit: 89 Festivities: 91 Co-operation and mitigation: 93 111 Between communities: 93 Within the town: 93 Quarter relations: 95 Protecting one's own: 96 Remittance Money 97 Chapter 7, Urbanisation: 102-122 Before Independence in 1967: 106 1970s: Housing crisis: 107 Construction curtailed: 108 Late 1970s- 1980s: Rapid expansion: 109 1990 - Today: 111 Exacerbating factors: 113 Expansion and land shortage 115 Chapter 8, The Consequences of Expansion: 123-166 The continued importance of the dispersal systems: 123 Encroachment and development: 125 Policy: 126 Watercourses: 126 Agricultural land: 133 Disrepair of structures within the flood dispersal network: 134 Public opinion: 138 Case studies: 140 Tarim 1989: 140 Shibam 1989 and 1996: 143 Tarim 1997: 145 Watercourse Encroachment in the Suburbs: 147 Jethma, a case study: 150 Settlement: 151 Flood defence plans and confiision: 152 Case study, Seiyun, 1982: 154 The response of the inhabitants of Jethma: 156 The effects of government involvement upon co-operation: 157 The effects of urbanisation upon co-operation: 159 Conclusions: 167-172 Bibliography: 173-190 Interviews: 191-194 Appendices: 195-215 Appendix 1, Floods 1225 -1997: 195 The floods of 1996: 153 Damage to the Wadi Hadhramaut: 159 Appendix 2: Rainfall data firom selected stations in the Wadi Hadhramaut: 214 IV Table of Tables: Table 1. Estimates of mean annual nmoff 31 Table 2. Flood Summary, 1225-1997 35-37 Table 3. Width of walls by storey 50 Table 4. Results of tests performed on blocks of nuura 55 Table 5. Population of Seiyun, 1973-1994 104 Table 6. Population of Shibam, 1973-1994 104 Table 7. Population of Tarim, 1973-1996 105 Table 8. Population of the Govemorate of Hadhramaut, 1973-1996 105 Table 9. "Observed maximum flood peaks firom existing hterature." 1977 198 Table 10. "Observed maximum flood peaks firom existing Hterature." 1978 198 Table 11. "Observed maximum flood peaks firom existing Uterature." 1981 198 Table 12. "Observed maximum flood peaks firom existing hterature." 1987 199 Table 13. "Observed maximum flood peaks firom existing hterature." 1989 200 Table 14. Official estimates of casualties and household losses, July 1996 201 Table 15. Showing wadis and towns in the govemorates affected by the 1996 floods 202 Table 16. Showing estimated maximum flood flows in the Shabwa and Maarib regions, June 1996 203 Table 17. Official estimates of damage to the agricultural sector. July 1996 204 Table 18. Official estimates of Uvestock and beehive losses, July 1996 205 Table 19. Official estimates for infirastructural damage, July 1996 205 Table 20. Rainfall, June 1996 207 Table 21: Agricultural losses in the Wadi Hadhramaut, June 1996 209 Table of Figures: Fig. 1. Map of the Republic of Yemen. 14 Fig. 2. Map of the Wadi Hadhramaut. 20 Fig. 3. Flood Hydrograph, Wadi Surdud. 30 Fig. 4. Sketch of a Seiyuuni house with dikka. 51 Fig. 5. Sketch of house walls and foundations showing the sloped outer walls and straight inner walls. 51 Fig. 6. Methods of laying modar. 53 Fig. 7. Sketch of the layout of Seiyun. 73 Fig. 8. Sketch of Shibam, SaHiil, the watercourse and the Muuza'. 79 Fig. 9. Document of ownership for land in the suburb of Jethma. 114 Fig. 10. Plan of the suburb of Jethma. 118 Fig. 11. Buildings on the edge of a channel, Seiyun. 127 Fig.