An emergy-based input–output model for reassessing industrial water efficiency in the Loess Plateau, China

Abstract

The industrial added value per unit of water consumption (IAV/IWC) is widely recognized as a crucial metric for assessing the efficiency of industrial water usage in a country or region, reflecting the cost-benefit ratio of water resources in industrial sectors. From the perspective of full resource accounting, it remains ambiguous whether this indicator effectively reflects the input–output performance of water resources, given its rather simplistic and rudimentary calculation. This study introduces the concept of industrial emergy footprint and develops an emergy-based industrial water benefit model to systematically illustrate the transformation pathways of water resources and other resource elements within the industrial system. In addition, two novel indices—the water resource load index and the industrial sustainability development index—are proposed to facilitate the analysis of industrial development and prioritize investment in water resource industries, thereby offering guidance for regional industrial layout strategies, particularly in water-scarce areas. A case study in Yulin City, located in the Loess Plateau of China, illustrated that the emergy approach more effectively and scientifically quantifies the flow and efficiency of water resource utilization in industrial production across different regions. Compared with traditional industrial water use efficiency evaluation methods dominated by economic benefits, the emergy-based approach offers distinct advantages in elucidating the resource input–output process and enhancing resource allocation efficiency. The findings on regional geographical heterogeneity indicate that Dingbian, Suide, and Qingjian counties, characterized by their reliance on agricultural products and cultural tourism, exemplify the most advantageous areas for sustainable industrial growth in terms of resource usage efficiency and green industrial development. Conversely, Hengshan county, which relies primarily on coal mining and related energy industries, demonstrated a low return on industrial benefits per unit of water input and therefore should be excluded from substantial investments in water resources. Overall, this work offers a unique perspective on understanding industrial water efficiency across all resource inputs. It broadens the area of efficiency evaluation and provides vital insights for green development and sustainable resource management.