Abstract:

Sand, gravel, and crushed rock—together referred to as construction aggregates—are the world’s most extracted solid materials by mass. China’s annual consumption of construction aggregates reached over 20 billion tons in 2018, accounting for nearly half of global consumption. This article provides an overview of the use of sand and gravel in China, including current supply and demand conflicts and the impacts of mining, transportation, and use. We highlight that: ① the national demand for sand and gravel has continued to grow in the last two decades; crushed rock has become the main source of construction aggregates, whereas the supply of river sand has significantly declined; and ② there are significant environmental, economic, and social challenges associated with sand and gravel mining, transportation, and use, including the emergence of illicit supply networks. We then discuss opportunities to ensure sand and gravel supply, minimize mining impacts, and promote sustainable trajectories for the Chinese aggregates industry. First, the quantification of the material flows and stocks of construction aggregates that includes geological and anthropogenic stocks is crucial to identify supply bottlenecks and ensure more efficient use of resources. This requires establishing a reliable data monitoring system. Second, the government should increase investment and establish relevant institutions to optimize supply systems and minimize their impacts, strengthen the regulatory framework, promote the uptake of alternative materials, and establish standards and implement best practices in the aggregates industry. Finally, interdisciplinary integrated research is needed to analyze the existing challenges associated with the supply of sand and gravel resources as well as the potential and risks of adaptation strategies.

Key words: construction aggregates, telecoupling, regional scarcity, supply and demand conflict