Overcoming challenges for implementing nature-based solutions in deltaic environments: insights from the Ganges-Brahmaputra delta in Bangladesh

Abstract

The Ganges-Brahmaputra (GB) delta is one of the most disaster-prone areas in the world due to a combination of high population density and exposure to tropical cyclones, floods, salinity intrusion and other hazards. Due to the complexity of natural deltaic processes and human influence on these processes, structural solutions like embankments are inadequate on their own for effective hazard mitigation. This article examines nature-based solutions (NbSs) as a complementary or alternative approach to managing hazards in the GB delta. We investigate the potential of NbS as a complementary and sustainable method for mitigating the impacts of coastal disaster risks, mainly cyclones and flooding. Using the emerging framework of NbS principles, we evaluate three existing approaches: tidal river management, mangrove afforestation, and oyster reef cultivation, all of which are actively being used to help reduce the impacts of coastal hazards. We also identify major challenges (socioeconomic, biophysical, governance and policy) that need to be overcome to allow broader application of the existing approaches by incorporating the NbS principles. In addition to addressing GB delta-specific challenges, our findings provide more widely applicable insights into the challenges of implementing NbS in deltaic environments globally.

Greening the dike revetment with historic sod transplantation technique in a living lab

“…Furthermore, our experiment with sod transplantation could inspire future managed realignments. For instance; within the Shoreline Management Plans in the UK (e.g., in Wales, Buser, 2020), as part of the Belgian Sigma Plan (FWA, 2006), or with the tidal river management approach in Bangladesh (e.g., Gain et al, 2022). In double dike managed realignments, the area between the two dikes can serve as a dike vegetation nursery.…”

Sediment delivery to sustain the Ganges-Brahmaputra delta under climate change and anthropogenic impacts

“…These naturalsystem responses to climate variability support conclusions from the modeling of future scenarios 38,100 and modern field-based studies 83,90 that the delta is not inherently doomed to drown. Instead, proper management of sediment resources, particularly within at-risk coastal regions 85,88 , may provide security for coastal populations and livelihoods often presented as unviable under future climate scenarios 6,13,84,101 . However, the persistence of a doomed-to-drown narrative for Bangladesh may perpetuate dystopian views in which particular regions of the delta or livelihoods are considered unsustainable and thus become subject to maladaptive policies 84 and may remove attention from the importance of international agreements to coordinate the transport of sediment across national boundaries.…”

“…12 Bangladesh Open University, Board Bazar, Gazipur, Bangladesh. 13 Department of Earth and Atmospheric Sciences, University of Houston, Houston, TX, USA. 14 Soil Geography and Landscape Group, Wageningen University, Wageningen, Netherlands.…”

“…These recognitions are important because the fate of river deltas and their growing populations are closely tied to riverine sediment supply 10 , which has a direct effect on land reclamation efforts, household migration decisions, and the ability to occupy marginal (vulnerable) lands [13][14][15] . For instance, the relocation of >20,000 Rohingya refugees to a newly emergent tidal island in the Ganges-Brahmaputra river-mouth estuary is a vivid example involving each of these issues 16,17 .…”

Natuur-gebaseerd beheer als grootste gemene deler voor klimaatrobuuste en duurzame rivier- en beeksystemen

“…Op initiatief van de lokale gemeenschap wordt een eeuwenoude techniek in ere hersteld om tijdelijk water toe te laten in omdijkte agrarische percelen langs de rivier. Zo is er meer ruimte voor het water tijdens hoge regenval en wordt een laagje vers sediment op de percelen gebracht (Gain et al, 2022).…”