Water-energy nexus based on modified multiregional input-output model within China

Rapid urbanization and sustained population growth have led to shortage of water resources, depletion of fossil energy and negative environmental impacts in China. Water utilization and energy consumption are intertwined in the socio-economic network, and their coupled relationships should be taken into accounts. Taking China's 30 regions in 2012 as the case, better balance management of regional energy and water can be achieved through a unified measurement framework based on exergy. By tracing the sum of energy and water flow in different regions, a modified multi-regional input-output (MRIO) model based on exergy theory is established to expound the water-energy nexus. The results show that Guangdong province held the top value among all the 30 regions, contributing 11.80% in national embodied consumption, followed by Jiangsu, Shandong, Zhejiang and Shanghai. Overall, the economically-developed coastal regions in the east are the top users. Shandong, Hebei, Liaoning, Jiangsu and Henan are the top five exporters of embodied water-energy from other regions. Guangdong, Jiangsu, Zhejiang, Shanghai and Beijing are the major importers of embodied water-energy. The main export import pairs are Shandong-Guangdong, Hebei Beijing, Hebei-Guangdong, and Hunan-Guangdong, indicating that there are strong connections between these pairwise regions. Furthermore, Beijing and Zhejiang demonstrate their higher efficient use of embodied water-energy to generate economic benefits. The proposed nexus approach may help the policymakers to ameliorate the shortage of energy and water and access the sustainable development of national and regional ecosystem. (C) 2019 The Authors. Published by Elsevier Ltd.