Research on the relative threshold of sustainable development of the complex system in the Yellow River Basin

Abstract

As a complex system, the sustainability of basins is crucial for the development and stability of human society. This study creatively combined Otsu algorithm with analytic hierarchy process to determine the relative threshold of sustainable development of the Yellow River basin system, aiming to provide a new perspective for the application of threshold theory to the study of sustainable development. The results showed that among the 24 sustainable development evaluation indicators, the Per Capita Cultivated Area (F24) had the greatest impact, while the Ecological Water use (F2) and Agricultural Water use (F19) indicators had the greatest impact range. For different subsystems, the sustainable development indices of the eco-environment subsystem in the upstream of the Yellow River exhibited more significant changes, while that of the socio-economic subsystem exhibited more prominent changes in the midstream. However, the sustainable development indices of the water-sand subsystems in the upstream, midstream, and downstream fluctuated greatly, with a maximum value occurring downstream. The sustainable development threshold was further determined to be 0.408 for the complex system in the Yellow River Basin. The sustainable development thresholds differed in upstream, midstream, and downstream, which ranged from 0.4201 to 0.4524. Based on the sustainable development threshold, the sustainable development status of the Yellow River Basin had continued to improve since 2017, and a high level of sustainability had been maintained. However, the sustainable status is a dynamic process of change, and changes in natural conditions or policies may affect the state of sustainable development.