Fig. 3: Sensitivities of sediment–cost trade-offs and energy capacity expansion pathways to decarbonization targets and electricity transmission capacities.
From: Strategizing renewable energy transitions to preserve sediment transport integrity
a, Markers from top to bottom denote the optimal sequences of dam construction under 16 plausible futures, each combining varying levels of decarbonization targets and degrees of transboundary cooperation. For clarity, we showcase only one low-impact hydropower portfolio along its optimal sequence. The dashed line separates low-impact vs high-impact hydropower plants with a threshold of 5% reduction in annual sediment supply compared to the status quo. Eight representative scenarios (S0, F0 and L1–L6) are highlighted for detailed analysis of electricity system pathways in b. Scenario S0 represents the status quo of the hydropower portfolio combined with T1.5°C decarbonization target and OPTIMIZED transmission capacity. Scenario F0 has the same decarbonization target and transmission capacity as S0, but for full hydropower development. Scenarios L1–L6 represent the development of only low-impact dams. L1 corresponds to the T1.5°C decarbonization target and OPTIMIZED transmission capacity. Scenarios L2, L3 and L4 reflect changes in transboundary electricity transmission restrictions based on L1, and L5 and L6 reflect changes in decarbonization targets based on L1. b, Temporal evolution of the electricity generation mixes from 2030 to 2050 for the eight highlighted scenarios. Country-specific generation and newly installed capacities in these eight scenarios can be found in Supplementary Figs. 5–9 and Extended Data Fig. 4, respectively. Uncertainty analysis related to Fig. 3 can be found in Extended Data Fig. 2 and Supplementary Figs. 1 and 2.
