Developing a copula-based input-output method for analyzing energy-water nexus of Tajikistan

Energy and water are closely related and restricted, which hinder the socioeconomic sustainable development associated with resources pressure. In this study, a copula-based input-output analysis (CIOA) method is developed for analyzing energy-water nexus (EWN) through incorporating input-output analysis (IOA), ecological network analysis (ENA), and copula within a framework. The CIOA method cannot only identify key consumption sectors and system characteristics but also build a quantitative EWN dependence structure. CIOA is applied to analyzing EWN system of Tajikistan, where 45 scenarios based on different water-saving rates and joint probabilities are examined to unveil interactions of energy and water. Some major findings are: (i) household is the key final demand, in which manufacturing (MAN) is the main embodied energy consumer, and food crop planting (FCP) is the main embodied water consumer; (ii) the utilization efficiencies of energy (35.9 tce/103$) and water (0.92 m3/$) are both low; however, the circulation and stability of water system are better than those of energy system; (iii) energy-water collaborative conservation can be realized in FCP, cash crop planting (CCP) and service (SER) sectors, especially when the energy-saving rate of SER reaches about 50%. The findings suggest Tajikistan should improve the energy-water utilization efficiency and establish a cross-sectoral cooperation management pattern for supporting its economic development and resources conservation sustainbility.