An evaluation of the hydropower planning alternatives at the upper reaches of Yellow River by considering carbon footprints

As a precautionary tool for decision-makings towards sustainable development, strategic environmental assessment (SEA) is quite promising in coping with climate change by taking the advantage of alternatives evaluation as early intervention and planning optimization. Despite of the acknowledged merits, the current alternatives evaluation has presented a weakness when tackling with the climate factors in practice due to an evident lack of carbon-related indicators. The challenge is even more pronounced in hydropower planning for the most sensitive response to climate, the most complicated impacts to evaluate and the recent doubts about the nature as a clean energy. Considering the assignable carbon emissions from the hydropower engineering including pre-treatment, construction, operation and decommission, six indicators of carbon footprint were selected and integrated with the conventional eco-environment and socio-economic considerations for evaluating four alternatives in the SEA of Upper Yellow River hydropower planning in China. The total 24 indicators were marked by the invited experts, and weighted by employing the BP neural network. The ranked marks from invited experts and improved by BP neural network weighting showed that the alternative II is the best among the four, indicating the slightest environmental impacts, the minimal carbon emissions, and the highest socioeconomic benefits. This study delivered an improved framework based on the conventional rapid impact assessment method (RIAM) and carbon footprint assessment, and provided a practical technical solution for evaluating planning alternatives in the context of green hydropower development.