THE MEGA-DELTAS OF ASIA

Project Title Asian Mega-deltas: Monsoon circulation in relation to deltaic-coastal hazards and future mitigation – millennial to seasonal dimensions

Project Leader: Zhongyuan Chen, Department of Geography, East China Normal University, Shanghai 200062, China

Collaborating Countries: Australia; Bangladesh; China; France; Germany; India; Indonesia; Japan, Korea; Malaysia; Nepal; Pakistan; Sri Lanka; Sudan; Thailand; UK; USA; Vietnam

Non-technical summary
     Starting from March 2007, this APN megadelta project begins its 2-year phases emphasizing on monsoon circulation in relation to deltaic-coastal hazards and future mitigation. Involved deltas are the Huanghe (Yellow), Changjiang (Yangtze), Zhujiang (Pearl), Song Hong (Red), Mekong, Chao Phraya, Ayeyarwady (Irrawaddy), Ganges- Brahmaputra (B-G), and Indus etc. The project has been schemed at quarterly base with designated tasks. A combined pre-meeting and workshop was firstly held under the title of ‘Delta Eve lotion and Deltas at Risk’, July 5-6, 2007, Vietnamese Academy of Science and Technology, Hanoi, Vietnam. Except discussion among project leaders, one-day workshop gathered about 60 local participants to exchange with project leaders in terms of the Yellow River, Yangtze River, Red River, and B-G River delta systems. The workshop result was quite fruitful in respect of knowledge dissemination through communication. Following project plan, the major combined APN-IGCP conference was successfully held in Bangladesh – Dhaka Venue, January 6 – 13, 2008. This provides a unique forum for all participants to demonstrate the results of delta-coast monsoonal processes and environmental hazard assessment. About 100 participants from 18 countries attended the meeting, of which 56 were from outside Bangladesh and rest were from local. Government officers and administrators from Bangladesh government were invited to attend the conference, to actively interact with all participants, and to listen to the comments from scientists. The conference reaches climax warmed by 78 thematic presentations and 25 poster presentations. A field trip to Sunderban wetlands of the B-G delta was followed to view on-site impact Cyclone of Sidr, which devastated the coastal properties with death toll of >3000. Tutorial training to younger scientists were also given in the field. All together, this conference is significantly beneficial for all, in light of the great contribution from Asia Megadelta networks that has been established since 2004.

Project Objectives
     This APN megadelta project is aiming at further strengthening of regional capacity networks to deal with delta-coast environmental constraint in response to global change. This collaboration, following our previous effort, will further strengthen not only scientific observation of regional scale, but, more importantly, communication with local government officer, administrator, and decision-maker. Through this great effort being made by individual delta-coast scientists from each Asia megadeltas (area, the project tends to approach the goal that focuses on monsoonal precipitation and topographical change, which will help assess coastal environmental hazards and future mitigation.

Relevance to the APN’s Science and Policy Agendas
     The proposed project will focus on monsoon circulation in relation to hazard mitigation on deltaic-coastal regions. Specifically, the study will coordinate regional climatological databases with the process-response model developed in our previous APN Asia megadelta project (2003-05). With an established network of participants (>100, mostly from developing countries), the proposed study is in a strong position to integrate current understanding of the Asian monsoon with the resulting morphological modification of regional coastal environments, particularly via controls on precipitation and runoff. We believe that there is a persistent gap between science, assessment, and policy. Therefore, this study is trying to fill in this gap by the planned research developments and regional workshops under CAPaBL, aiming at an effective communication among physical, social scientists, and policy-makers towards policy modification to maintain a sustainable delta-coast system

Work undertaken and results to date
     Up to-date, the project has been carried out successfully as schemed at quarterly base. A pre-meeting and associated workshop (Hanoi venue, and the major conference (combined APN-IGCP475, Dhaka venue) were successfully held. Totally, >160 participants from 18 countries were involved to the meeting. A project website (http://www.megadelta.ecnu.edu.cn) is established to disseminate the project results and on this base, the regional collaboration has been further strengthened. The project leaders will further our great effort to link governmental offices for an effective communication leading to a better policy modification in the future.

Self evaluation against project objectives
     We are satisfactory while assessing our project that was initiated in the early of 2007. The project is soundly progressing on the track aiming at 1) strengthening regional capacity of networks, 2) establishing a regional database of Asia megadelta; 3) strengthening communication with local governmental offices, administrators and decision makers, etc; 4) disseminating knowledge of delta-coast environmental constraint due to global change, via conference, workshop, publication and website that has been established.
(http://www.megadelta.ecnu.edu.cn)

Acknowledgments
     This Asia megadelta project is financially supported by APN (Grant no. ARCP2007-16NMY). Funding from IGCP-475 Project, Japan Geological Survey and East China Normal University is also collected to support the project activity. We are particularly indebted to all participants from different countries, who have been actively involved into this project, in terms of their invaluable knowledge, accessible database and methods applicable to the delta-coast fields.

Publications (to date and/or pending)
Chen, Z.Y,, Watanabe, M., Wolanski, E. (2007) Sedimentological and ecohydrological processes of Asian deltas: The Yangtze and the Mekong. Estuarine, Coastal and Shelf Science, vol. 71, 1-2.
Choi, M.S., Yi, H,I., Yang, S.Y., Lee, C.B., Cha, H.J. (2007) Identification of Pb sources in Yellow Sea sediments using stable Pb isotope ratios. Marine Chemistry, vol. 107, 255-274.
Garcia-Garcia, A., Orange, D.L., Miserocchi, S., Correggiari, A., Langone, L., Lorenson, T.D., Trincardi, F., Nittrouer, C.A. (2007) What controls the distribution of shallow gas in the Western Adriatic Sea? Continental Shelf Research, vol. 27, 359-374.
Hori, K., Saito, Y. (2007) An early Holocene sea-level jump and delta initiation. Geophysical Research Letters, vol. 34, L18401, doi:10.1029/2007GL031029.
Hori, K., Saito, Y. (2007) Classification, architecture, and evolution of large-river deltas. In A. Gupta, ed., Large Rivers: Geomorphology and Management, John Wiley & Sons, 75-96.
Koshikawa, M.K., Takamatsu, T., Takada, J., Zhu, M.Y., Xu, B.H., Chen, Z.Y., Murakami, S., Xu, K.Q., Watanabe, M. (2007) Distributions of dissolved and particulate elements in the Yangtze estuary in 1997-2002: Background data before the closure of the Three Gorges Dam. Estuarine, Coastal and Shelf Science, vol. 71, 26-36.
Li, M.T., Xu, K.Q., Watanabe, M., Chen, Z.Y. (2007) Long-term variations in dissolved silicate, nitrogen, and phosphorus flux from the Yangtze River into the East China Sea and impacts on estuarine ecosystem. Estuarine, Coastal and Shelf Science, vol. 71, 3-12.
Liu, Z.X., Berne, S., Saito, Y., Yu, H., Trentesaux, A., Uehara, K., Yin, P., Liu, J.P., Li, C.X., Hu, G.H., Wang, X.Q. (2007) Internal architecture and mobility of tidal sand ridges in the East China Sea. Continental Shelf Research, vol. 27, 1820-1834.
Liu, J., Saito, Y., Wang, H., Yang, Z.G., Nakashima, R. (2007) Sedimentary evolution of the Holocene subaqueous clinoform off the Shandong Peninsula in the Yellow Sea. Marine Geology, vol. 236, 165-187.
Palinkas, C.M., Nittrouer, C.A. (2007) Modern sediment accumulation on the Po shelf, Adriatic Sea. Continental Shelf Research, vol. 27, 489-505.
Qiao, S.Q., Yang, Z.S., Pan, Y.J., Guo, Z.G. (2007) Metals in suspended sediments from the Changjiang (Yangtze River) and Huanghe (Yellow River) to the sea, and their comparison. Estuarine, Coastal, and Shelf Science, vol. 74, 539-548.
Saito, Y. (2008) Coastal characteristics and changes in coastal features. In Mimura, N. (ed.), Asia-Pacific Coasts and Their Management: The states of Environment. Coastal Systems and Continental Margins, Vol. 11. Springer, in press.
Saito, Y., Chaimanee, N., Jarupongsakul, T., Syvitski, J.P.M. (2007) Shrinking megadeltas in Asia: Sea-level rise and sediment reduction impacts from case study of the Chao Phraya Delta. LOICZ INPRINT, no. 2007/2, p. 3-9.
Syvitski, J.P.M., Saito, Y. (2007) Morphodynamics of deltas under the influence of humans. Global and Planetary Change, vol. 57, 261-282.
Tamura T., Saito Y., Sieng, S., Ben, B., Kong, M., Choup, S., Tsukawaki, S. (2007) Depositional facies and radiocarbon ages of a drill core from the Mekong River lowland near Phnom Penh, Cambodia: evidence for tidal sedimentation at the time of Holocene maximum flooding. Journal of Asian Earth Sciences, vol. 29, 585-592.
Tamura, T., Nanayama, F., Saito, Y., Furakami, F., Nakashima, R., Watanabe, K. (2007) Intra-shoreface erosion in response to rapid sea-level fall: depositional record of a tectonically-uplifted strand plain, Pacific coast of Japan. Sedimentology, vol. 54, 1149-1162.
Tamura, T., Murakami, F., Nanayama, F., Watanabe, K., Saito, Y. (2008) Ground-penetrading radar profiles of Holocene raised-beach deposits in the Kujukuri strand plain, Pacific coast of eastern Japan. Marine Geolog, (in press).
Tamura T., Saito Y. and Masuda F. (2007) Variations in depositional architecture of Holocene to modern prograding shorefaces along the Pacific coast of eastern Japan. SEPM Special Publication, (in press).
Wang, H.J., Yang, Z.S., Saito, Y., Liu, J.P., Sun, X.X., Wang, Y. (2007) Stepwise decrease of the Hunaghe (Yellow River) sediment load (1950-2005): Impacts of climate change and human activities. Global and Planetary Change, vol. 57, 331-354.
Wang, H.J., Yang, Z.S., Li, Y.H., Guo, Z.G., Sun, X.X,. Wang, Y. (2007) Dispersal pattern of suspended sediment in the shear frontal zone off the Huanghe (Yellow River) mouth. Continental Shelf Research, vol. 27, 854-871.
Wang, Z.H., Li, L.Q., Chen, D.C., Xu, K.Q., Wei, T.Y., Gao, J.H., Zhao, Y.W., Chen, Z.Y., Matanate, W. (2007) Plume front and suspended sediment dispersal off the Yangtze (Changjiang) River mouth, China during non-flood season. Estuarine, Coastal and Shelf Science, vol. 71, 60-67.
Wei, T.Y., Chen, Z.Y., Duan, L.Y., Gu, J.W., Saito, Y., Zhang, W.G.,Wang, Y.H., Kanai, Y. (2007) Sedimentation rates in relation to sedimentary processes of the Yangtze Estuary, China. Estuarine, Coastal and Shelf Sciences, vol. 71, 37-46.
Xu, K.Q., Brown, C., Kwon, H.H., Lall, U., Zhang, J.Q., Hayashi, S., Chen, Z.Y. (2007) Climate teleconnections to Yangtze river seasonal streamflow at the Three Gorges Dam, China. International Journal of Climatology, vol. 27, 771-780.
Yang, S., Youn, J.S. (2007) Geochemical compositions and provenance discrimination of the central south Yellow Sea sediments. Marine Geology, vol. 243, 229-241.
Yang, Z.S., Liu, J.P. (2007) A unique Yellow River-derived distal subaqueous delta in the Yellow Sea. Marine Geology, vol. 240, 169-176.
Yang, Z.S., Lei, K., Guo, Z.G., Wang, H.J. (2007) Effect of a winter storm on sediment transport and resuspension in the distal mud area, the East China Sea. Journal of Coastal Research, vol. 23, 310-318.

Zong, Y., Chen, Z., Innes, J.B., Chen, C., Wang, Z., Wang, H. (2007) Fire and flood management of coastal swamp enabled first rice paddy cultivation in east China. Nature, vol. 449, 459-U4.