Security assessment and obstacle factors diagnosis of water-energy-food nexus based on pressure-state-response framework in Northwest China

In the context of population growth and increasingly scarce resources, the sustainability of water-energy-food nexus (WEFN) has been considered as a major global challenge. This study presented the evaluation index system of WEFN security based on pressure-state-response framework. Then the set pair analysis and variable fuzzy sets were supplied to evaluate the WEFN security in Northwest China from 2010 to 2019. Finally, obstacle degree model was adopted to diagnose the main factors affecting the WEFN security. The results indicated that over the years, in addition to response-subsystem, the safety level of the Northwest China WEFN had obvious spatio-temporal differentiation, which was always between critically safe and unsafe, but the overall trend was positive. In the pressure-subsystem, the WEFN security only in Gansu and Inner Mongolia was at a safe level; in the state-subsystem, the safe level of Ningxia and Shanxi was the worst; in the response-subsystem, the whole region was almost at an unsafe level. The annual average obstacle degree of three subsystems was compared as follows: pressure-subsystem > state-subsystem > response-subsystem. And, their obstacle factors were almost all related to water. The key to improving WEFN security of Northwest China in the future is to deal with the serious mismatch between water and energy resources.