Dieser Beitrag erschien bei Global Water Forum.
More dams are built these days than ever before. Their potential negative impacts are broad-ranging and must be thoroughly understood in order to address them. Yet the academic literature supposed to map these impacts remains limited in scope. This article outlines current biases in the scholarly work on the topic as well as these biases’ implications.
A major boom in dam development is under way with at least 3,700 dams1 either planned or already under construction. These are expected to increase global hydropower production by 73% to 1,700 GW1 in the coming years. 37 GW of capacity was added in 2014 alone2, equivalent to almost three times Africa’s current total installed capacity3. Asia is a particular hotspot of dam construction with capacity additions of almost 29 GW in 20142, more than in any other region of the world.
Yet dams remain extremely controversial due to their myriad environmental and social impacts. Dam-induced displacement is the most emotive issue4: up to 200 million people have been displaced because of infrastructure development in the past century5; possibly 80 million of these were displaced due to dams6. Examples of currently disputed large dam projects are Myanmar’s Myitsone Dam7, Brazil’s Belo Monte Dam8 or Mozambique’s Mphanda Nkuwa Dam9.
Many negative environmental and social impacts of large dams could be significantly mitigated with state-of-the-art knowledge and experience10 on planning and management practices. Yet dams’ negative impacts must be thoroughly understood in order to design tailor-made interventions addressing them. Scholarly work can be instrumental for both conceptualizing and mapping these impacts.
Academics have investigated dams’ impacts since the late 1950s11. Thousands of studies have been published until now on the topic by scholars from a variety of disciplines – both by social scientists (e. g. anthropologists, political scientists, sociologists, geographers and economists) as well as natural scientists (e. g. biologists or engineers). Publications on the topic have surged in the past 25 years12.
However, many significant knowledge gaps remain. This is the key finding of a study my colleagues at the University of Oxford and I have just published12. This study is the very first systematic review ever carried out on dams’ social impacts. For this purpose, we have created a sample of 217 articles on the topic at hand that we have systematically analysed across more than 40 categories.
These are five major insights from our work:
First, we found that scholars study dams that are much larger than the average dams built (Figure 1)13. Two mega-dams (China’s Three Gorges Dam, the world’s largest dam14, and India’s Sardar Sarovar Dam) are particularly well-studied, as our work evidences. This bias is problematic since the impacts of mega-dams may be very different to those of small(er) dams (this statement does not mean to imply that small(er) dams only result in small(er) impacts)15.
Second, we found that most of the literature (almost 90%) focuses only on these mega-dams’ resettlement area impacts. Yet dams’ spatial impacts go far beyond this. For instance, dam development may threaten the food security of 60 million people in the Mekong River Basin16 because of dams’ downstream impacts. In order to assess the viability of a project, dams’ resettlement area impacts as well as dams’ social impacts occurring downstream, upstream as well as for the entire country (and beyond) must be considered.
Third, we found that the vast majority of articles neglect perspectives beyond those of the displaced communities – a direct result from the focus on resettlement area impacts, we assume. For instance, only about 20% of articles present the view of the dam developer or the international donor in a dam project, compared to 80% of articles presenting the views of displaced communities.
Fourth, we found that almost no articles (only 5%) are positive regarding their overall judgement of dams’ social impacts. NGOs may be tempted to infer from this data that (allegedly objective) scientists largely condemn dams. Yet we fear that the identified bias in the unit-of-analysis focus (with an over-emphasis of displaced communities’ views) may have biased the judgement of scholars on the overall project since displaced communities are likely most critical of a dam.
Fifth, we found that most scholars (approximately 70%) only evaluate impacts that occur 5-10 years upon dam completion. Yet impacts can already commence in the planning phase17 (with governments withholding investments for villages to be displaced years prior to the construction start already, for instance) and may last for decades18. Such impacts must be highlighted by scholarly work in order to be addressed by practitioners.
The impact of academic work on practitioners is considered to be limited nowadays19. Yet perceptions of the social impacts of dams are driven in large part by the scholars analysing them. Indeed, this field of study is extremely applied. For instance, Thayer Scudder, arguably the world’s leading authority on the social impacts of dams, is currently consulting within Laos’ Nam Theun 2 Dam project20. Meanwhile, Michael Cernea, also an eminent scholar on the topic, was the World Bank’s senior advisor for sociology and social policy introducing sociological and anthropological approaches to the organization.
Yet our study suggests that practitioners must be extremely cautious when reading scholarly work on the social impacts of dams. Currently, decisions are taken to pursue small dams over large dams without a full understanding of the trade-offs involved because of an incomplete literature on the subject. Academic writings on the topic also do a disservice to the people who experience positive impacts of dam development, and those negatively impacted other than by resettlement from large dams.
The University of Oxford hosted a conference on dams and development in late 2014. All panellists – indeed, those supporting as well as those opposing the construction of large dams – agreed that more evidence is needed on the topic at hand. This is also showcased by the meta-synthesis my colleagues and I have carried out. I very much hope that our new study will stimulate debate among scholars researching dams’ social impacts. Much more research on this timely topic is urgently needed.
- Zarfl, C., Lumsdon, A. E., Berlekamp, J., Tydecks, L., & Tockner, K. (2014). A global boom in hydropower dam construction. Aquatic Sciences, 77(1), 161–170. http://doi.org/10.1007/s00027-014-0377-0
- International Hydropower Association (IHA). (2015). 39 GW of hydropower added in 2014. Retrieved fromhttp://www.hydropower.org/blog/39-gw-ofhydropower added-in-2014
- Tortajada, C. et al (2012) Impacts of Large Dams: A Global Assessment. Water Resources Development and Management. http://www.springer.com/us/book/9783642235702
- Kirchherr, J., Charles, K.J. (2016) The social impact of dams: a new framework for scholarly analysis. Environmental Impact Assessment Review. In Press.
- (2000). Dams and Development – A New Framework for Decision-Making. World Commission on Dams. Retrieved from http://www.internationalrivers.org/files/attachedfiles/world_commission_on_dams_final_report.pdf
- Tortajada, C. (2014). “Dams: An Essential Component of Development.” J. Hydrol. Eng., 10.1061/(ASCE)HE.1943-5584.0000919, A4014005.
- Colson, E. (1967) Social Organization of the Gwembe Tonga. Manchester University Press.
- Kirchherr, J., Pohlner, H., Charles, K.J. (2016) Cleaning up the big muddy: a meta-synthesis of the research on the social impact of dams. Environemental Impact Assessment Review. In Press.
- Kibler, K.M., Tullos, D.D. (2013) Cumulative biophysical impact of small and large hydropower development in Nu River, China. Water Resources Research 49(6), 3104-3118.
- Plummer Braeckman, J., & Guthrie, P. (2015). Loss of value: effects of delay on hydropower stakeholders. Proceedings of the Institution of Civil Engineers -Engineering Sustainability, jensu.15.00027.
- Takesada, N. (2009). Japanese Experience of Involuntary Resettlement: Long-Term Consequences of Resettlement for the Construction of the Ikawa Dam. International Journal of Water Resources Development, 25(3), 419–430.
Julian Kirchherr is a doctoral scholar at the School of Geography and the Environment, University of Oxford. The final version of the University of Oxford study on the literature analysing dams’ social impacts can be accessed here. A free-of-charge pre-print version of the study is available here.