Evaluation of Revetment Works on Middle and Lower Reaches of Changjiang River from Carbon Emission Point of View

This article analyzes the carbon emission research progress of water conservancy industry, establishing the full-process carbon emission calculation list for the bank revetment works based on the life cycle assessment method and setting forth the concept of achieving the carbon source and carbon sink balance year in the life cycle of the bank revetment works, with a view to the characteristics of bank revetment works on the middle and lower reaches of Changjiang River. By using the carbon emission achievements of the materials used for the existing revetment works and selecting the Phragmites as a species for slope surface, analysis is conducted for the same case of three different typical bank revetment schemes in relation to carbon emission. The analysis results of the three revetment schemes indicate that the carbon emission of revetment works in each scheme mainly occurs in its materialization period, with little carbon emission occurred during the years of operation comparatively. Among the slope protection carbon emission parts of the three schemes in their materialization periods, the carbon emission in the concrete scheme is the highest, which is nearly one times as much as the other two, while that of the toe protection part is more than seven times as much as the other two, and it will take a long time for the concrete scheme to achieve the carbon balance year in the in-service stage. Comparing the traditional scheme with biological scheme, their carbon emission in the materialization stage is found basically equivalent, while the time needed by the traditional scheme to achieve the carbon balance year in the in-service stage is comparatively shorter. The carbon emission differences of each scheme in their materialization periods are attributable to the different extent of use of the high-energy consuming products - the cement and reinforcement, while the differences of net carbon sink in the in-service stage are due to the different slope protection structures and the materials used for them.