To explore the integrated security of water–energy–food systems, 26 indicators were selected from six aspects: water security, energy security, food security, water–energy system security, water–energy system security, and energy–food system security, and frequency analysis method was used to construct the integrated security evaluation index system for water–energy–food systems. The index weights were determined using the entropy weighting method. Then, the matter-element expansion model is refined and used to assess the overall security of the water, energy, and food systems in the Beijing–Tianjin–Hebei region. Evaluation metrics for the overall security of water–energy–food systems have been analyzed and studied in two dimensions, time and space. Empirical studies have shown that this model reflects the overall security of water–energy–food system. The evaluation results of the modified model are compared with those of the conventional matter-element inflationary model, and the feasibility and validity of the modified model are verified. Finally, using the index weight and the obstacle degree model, the main factors affecting the security of the water–energy–food system in the Beijing–Tianjin–Hebei region are discussed, and relevant suggestions are made to improve the security of the water–energy–food system.
This study provides a broad evaluation index system for water–energy–food (WEF) system security evaluation.
The matter-element extension model has been enhanced and applied to assess the WEF system in the Beijing–Tianjin–Hebei region, thereby enhancing the accuracy of the evaluation outcomes.
The security of water resources system, energy system, and energy system is the key to affect the security of the whole system.