SINTEF Energy Research, Norway.
Swansea University, UK.
Sci Total Environ. 2023 May 1;871:161940. doi: 10.1016/j.scitotenv.2023.161940. Epub 2023 Feb 2.
The Balkan region has some of the best conserved rivers in Europe, but is also the location of ~3000 planned hydropower dams that are expected to help decarbonise energy production. A conflict between policies that promote renewable hydropower and those that prioritise river conservation has ensued, which can only be resolved with the help of reliable information. Using ground-truthed barrier data, we analysed the extent of current longitudinal river fragmentation in the Balkan region and simulated nine dam construction scenarios that varied depending on the number, location and size of the planned dams. Balkan rivers are currently fragmented by 83,017 barriers and have an average barrier density of 0.33 barriers/km after correcting for barrier underreporting; this is 2.2 times lower than the mean barrier density found across Europe and serves to highlight the relatively unfragmented nature of these rivers. However, our analysis shows that all simulated dam construction scenarios would result in a significant loss of connectivity compared to existing conditions. The largest loss of connectivity (-47 %), measured as reduction in barrier-free length, would occur if all planned dams were built, 20 % of which would impact on protected areas. The smallest loss of connectivity (-8 %) would result if only large dams (>10 MW) were built. In contrast, building only small dams (<10 MW) would cause a 45 % loss of connectivity while only contributing 32 % to future hydropower capacity. Hence, the construction of many small hydropower plants will cause a disproportionately large increase in fragmentation that will not be accompanied by a corresponding increase in hydropower. At present, hydropower development in the Balkan rivers does not require Strategic Environmental Assessment, and does not consider cumulative impacts. We encourage planners and policy makers to explicitly consider trade-offs between gains in hydropower and losses in river connectivity at the river basin scale.
巴尔干地区拥有欧洲一些保护最好的河流，但也是预计将有助于实现能源生产脱碳的 3000 多个计划中的水电大坝的所在地。促进可再生水力发电的政策与优先考虑河流保护的政策之间存在冲突，只有在可靠信息的帮助下才能解决这一冲突。我们使用实地核实的障碍物数据，分析了巴尔干地区当前纵向河流破碎化的程度，并模拟了九个大坝建设情景，这些情景根据计划大坝的数量、位置和规模而有所不同。经过对障碍物漏报的校正，巴尔干河流目前被 83017 个障碍物分割，平均障碍物密度为 0.33 个障碍物/公里；这比欧洲平均障碍物密度低 2.2 倍，突显了这些河流相对未破碎的性质。然而，我们的分析表明，与现有情况相比，所有模拟的大坝建设情景都将导致连通性的显著丧失。如果所有计划中的大坝都建成，将导致连通性的最大损失（-47%），以无障碍长度的减少来衡量，其中 20%将影响保护区。如果只建造大型大坝（>10MW），则连通性的损失最小（-8%）。相比之下，如果只建造小水电大坝（<10MW），将导致 45%的连通性损失，而对未来水电容量的贡献仅为 32%。因此，许多小水电站的建设将导致不成比例的破碎化增加，而不会相应增加水电。目前，巴尔干河流的水电开发不需要进行战略环境评估，也不考虑累积影响。我们鼓励规划者和政策制定者在流域尺度上明确考虑在水电收益和河流连通性损失之间的权衡。
