Elsevier

Environmental Science & Policy

Volume 75, September 2017, Pages 111-120
Environmental Science & Policy

Tidal river management in the south west Ganges-Brahmaputra delta in Bangladesh: Moving towards a transdisciplinary approach?

https://doi.org/10.1016/j.envsci.2017.05.020Get rights and content

Highlights

  • Tidal river management (TRM) is practiced in part of Ganges-Brahmaputra Delta.

  • Multiple barriers exist for implementing TRM.

  • A transdisciplinary approach is examined to overcome TRM barriers.

  • The transdisciplinary approach can reshape TRM governing values and actions.

  • The proposed transdisciplinary approach can potentially be applied to TRM projects.

Abstract

Due to both natural and anthropogenic forces, the south west part of the Ganges-Brahmaputra coastal area is facing diverse problems such as waterlogging, salinity, and loss of biodiversity. In order to address these challenges, local people have identified ‘tidal river management (TRM)’ as a comprehensive approach for sustainably managing this part of the Ganges-Brahmaputra Basin. However, due to institutional limitations, mismanagement and social conflicts, application of the TRM approach is not straightforward. In order to identify existing implementation barriers and to effectively apply the TRM approach, a transdisciplinary approach is examined for its potential to inform the re-shaping of TRM governing values and actions. It is argued that a thorough application of a transdisciplinary framework is essential, supported by the active involvement of key agencies and local stakeholders. The proposed transdisciplinary framework can potentially be applied to TRM projects for solving waterlogging and associated problems in order to achieve greater sustainability of the area.

Introduction

The Ganges–Brahmaputra river delta is the home of more than 170 million people within a vast and low-lying coastal plain (Auerbach et al., 2015a). The south west part of the delta (see Fig. 1) in Bangladesh is comprised mainly of the Khulna, Jessore, Satkhira, and Bagerhat districts. The physical geography of the area is highly diverse and dynamic (Brammer, 2014). The history of the delta complex can be understood in terms of geological processes over 125 million years including the Gondwanaland break-up, collision of the Indian plate with the Burmese and Eurasian plate, development of the Himalayas and the evolution of the Ganges-Brahmaputra river system (Lindsay et al., 1991). The Ganges-Brahmaputra river system delivers sediment-laden water to the delta (Allison, 1998, Datta and Subramanian, 1997a) and carries the world’s highest annual sediment load (at least one billion tonnes per year). The delta is covered almost entirely by rich alluvial deposits from these rivers which are constantly shaped and reshaped through processes of river sedimentation and erosion (Datta and Subramanian, 1997b, Goodbred, 2003).

The delta faces multiple physical threats. The geological processes, crustal movements and compaction of the recent sediment have contributed to a broad regional land subsidence at a rate of 2–3 mm/year and more localised hotspots with higher subsidence (Brown and Nicholls, 2015, Nicholls et al., 2016). The eastward migration of the Ganges due to natural processes has also led to the effective cutting off of fluvial sediment and a major share of the freshwater flow in the south west coastal area (Allison et al., 2003, Hore et al., 2013). Considering future change, climate change induced sea level rise and cyclonic extreme events are also dominant physical features in the area. According to Delta Plan of Bangladesh (GoB, 2014), the sea level rise in Bangladesh will be slightly higher than the global average mean of 37–75 cm (Hinkel et al., 2014) by the year 2100. Considering global and regional climate scenarios, the baseline studies of Delta Plan also mention an increased projection of rainfall and temperature, with more intense events.

In addition to the above-mentioned physical processes, various anthropogenic and structural development activities have contributed to accelerated changes in the coastal zone (Hossain et al., 2016, Huq et al., 2015). Land use change through the intensification of shrimp culture has converted agricultural land and mangrove forest to brackish water aquaculture (Khan et al., 2015, Shameem et al., 2014). Although shrimp aquaculture contributes to economic benefits, it hampers environmental sustainability. Upstream water withdrawal since 1975 at the Farakka barrage in India (a barrage across the Ganges River, located in the Indian state of West Bengal, roughly 16.5 km from the border with Bangladesh) contributes to reduced freshwater flow during the dry season (Gain and Giupponi, 2014, Mirza, 1998). In addition, larger irrigation projects such as the Ganges-Kobadak (G-K) project also withdraw a significant portion of freshwater for agricultural purposes. Upstream water withdrawal and the G-K irrigation project have consequently increased water salinity (Gain et al., 2007, Gain et al., 2008) and induced high rates of sediment deposition in the south west coastal region. In parallel, coastal polders (earthen embankments) have been constructed since the 1960s in order to provide protection from floods and to increase agricultural production However, these polders have prevented silt from the rivers from being deposited on flood plains, resulting in high rates of sedimentation on the river bed, congesting both rivers and canals and causing many to dry out over a period of decades (Dewan et al., 2014, Dewan et al., 2015).

Thus, both natural and anthropogenic forces play important roles in the changes in social and ecological systems in the south west part of the Ganges-Brahmaputra coastal area. Such dynamic physical and anthropogenic process (de Die, 2013, van Staveren et al., 2016) are also linked with the historic evolution of water management practices from temporary earthen embankments to depoliticized community-based water management (Dewan et al., 2015). Failure to recognise the complex behaviour of this system and complex inter-dynamics of physical and social processes has had negative implications for managing these vital resources. As a consequence, the south west coastal area is facing diverse problems such as salinity, waterlogging and loss of biodiversity with attendant negative impacts on the local economy and sustainability.

In order to address complex problems such as waterlogging, salinity, siltation of river beds and drainage congestion, tidal river management (TRM) has been considered as an effective approach for sustainably managing the south west coastal area of the Ganges-Brahmaputra Basin (Hossain et al., 2015, Nowreen et al., 2014, van Staveren et al., 2016). Tidal river management involves the periodic cutting and closing of polders to accelerate land accretion (or reclamation). From their own experience and observation, local people have presented their reasoned arguments to water managers for breaching or cutting away polders to allow tidal flows for solving the problems. The TRM approach is capable of elevating the flood plain area by 1–3 m through natural siltation process within 3–5 years and hence, this can potentially solve permanent waterlogging in the floodplain and siltation of riverbeds (Jakarya et al., 2016, Khadim et al., 2013, Paul et al., 2013, Shampa and Pramanik, 2012, Tutu, 2005). Recently, several larger collaborative research projects (such as the Dynamic Deltas, see NWO (2011)) partly consider a TRM approach as an adaptation strategy.

TRM represents a departure from a sole focus on maximising agricultural development through engineered flood protection and land improvement to a more comprehensive approach that recognises the complex interplay of natural and anthropogenic forces and the importance of local knowledge and engagement. However, TRM implementation has proved to be challenging due to institutional limitations, mismanagement and social conflicts (Auerbach et al., 2015b, Rezaie et al., 2013) and has lacked interdisciplinary practice. Addressing waterlogging and flood risks, Auerbach et al. (2015a), for example, recommend a physical-based assessment of the impacts of polder construction on sediment deposition and distribution and suggest that systematically breaching embankment sections can facilitate sediment delivery and elevation recovery. Yet, such simple recommendations are based only on physical assessments and hence cannot realistically provide practical solutions without considering stakeholders’ attitudes. In contrast, Dewan et al., 2014, Dewan et al., 2015 consider public participation for resolving waterlogging issues but without undertaking scientific assessments of the problem.

It is evident that such complex approaches (such as TRM) cannot be understood by disciplinary scientific practices without taking into account an inter- and trans-disciplinary perspective. This paper argues that a transdisciplinary process is required for the successful implementation of a TRM approach and for achieving sustainability through reducing waterlogging, restoring navigability of the river, and increasing agricultural production. A transdisciplinary approach is useful when facts are contested, values in dispute, stakes high, and decisions urgent (Krueger et al., 2016). This study aims to evaluate and synthesise evidence of recently practised tidal river management in the Ganges-Brahmaputra Delta through the lens of a transdisciplinary research approach. Thus, this paper explores how a transdisciplinary approach can help integrate disciplinary paradigms and facilitate the integration of stakeholder and local community knowledge in TRM implementation.

It first discusses the history of the TRM approach, and illustrates it with three case studies of recently practised TRM in the Khulna and Jessore districts of the Ganges-Brahmaputra Delta. It then presents the key features of a transdisciplinary approach, and evaluates how far it can inform better implementation of the three selected case studies. Finally, lessons for future TRM implementation are drawn. The research adopted a mixed method approach primarily involving a qualitative case study design that sought to elicit stakeholder perceptions on the causes of TRM implementation problems, factors determining success and potential policy solutions, using two workshops, stakeholder interviews and site visits, along with quantitative data on sediment deposition, river water levels and socio-economic indicators from secondary sources.

Section snippets

Evolution of the ‘tidal river management’ approach

From the 17th century to 1950, water resources in the south west coastal area were traditionally managed by Zamindars (landlords). They were responsible for the construction of temporary low earthen embankments around tidal flats during eight dry months of the year to prevent tidal intrusion and to protect their agricultural lands. During the monsoon season (after the harvest), the embankments were dismantled to open the periodically flooded land for cattle grazing and open fishing on the tidal

Three recent ‘tidal river management’ projects

In the study area (Khulna-Jessore-Satkhira districts), TRM is operated in only 12 out of 35 beels. Initially, local people implemented TRM in some beels and afterwards government agencies (e.g., BWDB) implemented TRM. In this study, three beels were selected for detailed investigation: one being led by a local community and the other two by national authorities (one of which is currently being implemented). They were selected to present varying leadership approaches to TRM as a basis for

The successes and challenges of ‘tidal river management’

Because of its high potential for removing waterlogging in the beel and restoring navigability in the rivers, TRM has been acknowledged as a new important strategy for Bangladesh water management by policy makers and donor agencies. The scientific effectiveness of TRM is acknowledged by technical authorities on water resources management, with economic and social impact assessment (CEGIS, 1998) and mathematical modelling (IWM, 2008) providing scientific evidence in favour of TRM. In the case of

A transdisciplinary approach to guide TRM implementation

Transdisciplinary approaches have been promoted to address complex issues of socio-ecological systems as they support the establishment of a well-managed collaboration among experts from multiple disciplines, stakeholders and local communities (Krueger et al., 2016, Pohl, 2011). According to Lang et al. (2012), a typical transdisciplinary process can be conceptualised as structured around three building blocks: collaboratively framing the problem and building a collaborative team; co-producing

Tidal River Management through the lens of a transdisciplinary approach

The next three sub-sections explore some key features of TRM projects through the three phases of a transdisciplinary approach that then helps to overcome identified barriers (see Table 5). The following observations do not aim to provide strict guidance, as it is acknowledged that TRM is a dynamic, context-specific process; instead they offer insights and criteria to be considered when designing and implementing TRM, so as to support adequate consideration of the multiple benefits and impacts

Conclusions

The TRM approach has significant potential in generating positive consequences for land development, flood resistance and food security in the south west region of the Ganges-Brahmaputra Delta. In this study, important factors that support or hinder the successful implementation of existing TRM projects in the area have been identified and discussed. In order to address such multi-faceted challenges and conflicts, a transdisciplinary approach is a potentially useful governance device for

Acknowledgements

All authors would like to acknowledge the Leverhulme Trust (Project number IN-2014-014) for funding collaborative international network on IWRM. AK Gain is financially supported by the Alexander von Humboldt Foundation whose support is gratefully acknowledged. The authors also acknowledge Md. Ruhul Amin, Md. Hasan Ali and Kazi Rifat Ahmed for the GIS data. All authors equally contributed to the manuscript: A.K. Gain designed the research approach; D. Benson developed and described the

References (57)

  • M.S.I.I. Amir

    Socio-Technical Assessment of Sediment Management Options in Tidal Basins in Southwestern Bangladesh, Institute of Water and Flood Management

    (2010)
  • L.W. Auerbach et al.

    Flood risk of natural and embanked landscapes on the Ganges–Brahmaputra tidal delta plain

    Nat. Clim. Change

    (2015)
  • L.W. Auerbach et al.

    Reply to ‘Tidal river management in Bangladesh’

    Nat. Clim. Change

    (2015)
  • M.A. Awal

    Water logging in southwestern coastal region of Bangladesh: local adaptation and policy options

    Sci. Postprint

    (2014)
  • M.E. Bates et al.

    Delta subsidence reversal, levee failure, and aquatic habitat—a cautionary tale

    San Franc. Estuary Watershed Sci.

    (2013)
  • CEGIS

    Environmental and Social Impact Assessment of Khulna-Jessore Drainage Rehabilitation Project

    (1998)
  • L. de Die

    Tidal River Management: Temporary Depoldering to Mitigate Drainage Congestion in the Southwest Delta of Bangladesh

    (2013)
  • D.K. Datta et al.

    Texture and mineralogy of sediments from the Ganges-Brahmaputra-Meghna river system in the Bengal Basin, Bangladesh and their environmental implications

    Environ. Geol.

    (1997)
  • C. Dewan et al.

    The imposition of participation? The case of participatory water management in coastal Bangladesh

    Water Altern.

    (2014)
  • C. Dewan et al.

    Evolution of water management in coastal Bangladesh: from temporary earthen embankments to depoliticized community-managed polders

    Water Int.

    (2015)
  • H.A. Fakir

    Tidal River Management (TRM): Khulna-Jessore Drainage Rehabilitation Project (KJDRP) Area

    (2008)
  • A.K. Gain et al.

    Impact of the Farakka Dam on thresholds of the hydrologic flow regime in the Lower Ganges River Basin (Bangladesh)

    Water

    (2014)
  • A.K. Gain et al.

    An assessment of water governance trends: the case of Bangladesh

    Water Policy

    (2012)
  • A.K. Gain et al.

    Effect of river salinity on crop diversity: a case study of South West Coastal Region of Bangladesh

    Nepal Agric. Res. J.

    (2007)
  • A.K. Gain et al.

    Impact of river salinity on fish diversity in the South-West Coastal Region of Bangladesh

    Int. J. Ecol. Environ. Sci.

    (2008)
  • K.A. Gain et al.

    From flood control to water management: a journey of Bangladesh towards Integrated Water Resources Management

    Water

    (2017)
  • GoB

    Bangladesh Delta Plan 2100 Formulation Project, Inception Report

    (2014)
  • K.N.H. Haque et al.

    Participatory environmental governance and climate change adaptation: mainstreaming of tidal river management in South-west Bangladesh

  • Cited by (56)

    • Sustainability of the coastal zone of the Ganges-Brahmaputra-Meghna delta under climatic and anthropogenic stresses

      2022, Science of the Total Environment
      Citation Excerpt :

      Until the 1950s, the tidal floodplain in the GBM delta (in Bangladesh) was strongly connected to the river system, so that it functioned as a natural sedimentation basin. Local communities managed the floodplain through construction of temporary low height earthen embankments during the eight dry months of the year (Gain et al., 2017) to protect crops against salinity intrusion. These temporary embankments were submerged during the monsoon flooding, thus enabling quasi-natural inundation and sedimentation processes on the tidal floodplains.

    View all citing articles on Scopus
    View full text