Epistemic community in transboundary river regime: a case study in the Mekong River Commission regarding mainstream hydropower development.

Despite the importance of transboundary water management, cooperation mechanisms are limited, especially in the case of Mekong River basin where environmental and social aspects are threatened by recent anthropogenic pressures like hydropower development. Existing transboundary mechanism such as the Mekong River Commission (MRC) is challenged to facilitate the cooperation between riparian states. An epistemic community (EC) is considered to effectively influence international governance and is studied as part of transboundary river regimes. The existence of an MRC EC is part of that regime but understanding about its characteristics is yet limited. This research aims to fill in the gap by unraveling the main features of the EC in relation to hydropower development. We analyze shared causal beliefs and policy goals that developed in the EC framework of Haas applying literature review and semi-structured interviews of experts. Results show that the community experts share causal beliefs and policy goals only to a limited extent while disagreeing on many aspects. It resembles a "disciplined" or "professional" group rather than an EC. This suggests that the knowledge factor has not gained proper influence and attention in the region, resulting in incoherent policy advice leading to policymakers developing policies based on incomplete and fragmented knowledge. The role of the MRC in the decision-making process could become more relevant if it would facilitate the development of an EC. Bringing key stakeholders including policymakers and experts into a platform where policy goals and causal beliefs are facilitated to reach possible consensus is recommended. Narrowing the science-policy gap while acknowledging differences in interests and policy objectives is crucial to reach a sustainable transboundary management of the Mekong River given its rapid development, especially on hydropower.

Sand mining in the Mekong Delta revisited - current scales of local sediment deficits.

The delta of the Mekong River in Vietnam has been heavily impacted by anthropogenic stresses in recent years, such as upstream dam construction and sand mining within the main and distributary channels, leading to riverbank and coastal erosion. Intensive bathymetric surveys, conducted within the Tien River branch during the dry and wet season 2018, reveal a high magnitude of sand mining activities. For the year 2018, an analysis of bathymetric maps and the local refilling processes leads to an estimated sand extraction volume of 4.64 [Formula: see text] 0.31 Mm[Formula: see text]/yr in the study area, which covered around 20 km. Reported statistics of sand mining for all of the Mekong's channels within the delta, which have a cumulative length of several hundred kilometres, are 17.77 Mm[Formula: see text]/yr for this period. Results from this study highlight that these statistics are likely too conservative. It is also shown that natural sediment supplies from upper reaches of the Mekong are insufficient to compensate for the loss of extracted bed aggregates, illustrating the non-sustainable nature of the local sand mining practices.