Modern canals integrate multi-functional needs such as shipping, flood control, water supply, irrigation, ecology, and tourism. There are many challenges in construction and operation, such as out-of-balance water and sediment transport, regional water security, ecological environment protection, long-life safety of structures, and low carbon. The need for China’s modern canal construction is increasingly urgent. However, the relevant fundamental research is relatively weak. The key theories and technologies of green construction and operation have yet to be broken through, and there is an urgent need to build systematic theories for synergistic regulation of safety and low carbon during the whole life of the canal project. Based on the discussion on the 362nd Shuangqing Forum of the National Natural Science Foundation of China (NSFC), this paper reviews the development history of artificial canals and the research status of modern canal engineering, puts forward the core connotation of modern canal engineering, summarizes the key technical problems faced by the green construction and operation for modern canal engineering in China, condenses the major scientific issues that need to be paid attention to and solved in the next 5-10 years for green construction and operation of modern canal engineering, and discusses the frontier research direction and the strategy of science funding in the related fields, which have important guiding significance for enabling the construction of large-scale cross-water canal projects in China.

In the context of China’s ‘carbon peak and carbon neutrality’ strategy, cold energy, as a new type of green energy, has received widespread attention and emphasis. A series of innovative cold energy utilization technologies have emerged in response. However, the cold energy industry currently faces challenges such as low utilization rates, lack of top-level planning, insufficient innovation in key technologies, and limitations on large-scale applications. This article summarizes and forecasts the key technologies related to the comprehensive and efficient use of cold energy, cryogenic materials, and pipeline equipment. As an essential infrastructure of the cold energy industry, the pipeline system is analyzed in terms of its operating conditions, potential risks and failure modes, and key technologies. The article identifies the challenges faced by cold energy industry pipeline technologies and the development trends of cold energy utilization pipeline technology. It proposes recommendations for the efficient use of cold energy and the development of its pipeline systems, aiming to provide robust support for the high-quality development, efficient and stable operation, safety assurance, and energy conservation and emission reduction of the cold energy industry.