Systemic and explicit approaches to assessing the impact of natural and human drivers on the co-evolution of social-ecological systems in the Heihe River Basin, China

The increasing crossing of critical thresholds of global social-ecological systems (SES) calls for an explicit and systemic assessment of human impact on the ecosystem. This paper aims to integrate multi-disciplinary approaches for a systemic and quantitative representation and measurement of the co-evolution of SES and their responses to both natural and human drivers over a long period. We used the ‘Coupling Coordination Degree’ (CCD) for defining and measuring the co-evolution of socio-ecological systems (SES), the combined text mining technique and content analysis for systemically measuring the human driver, boosted regression tree for analyzing the relative contribution of natural and human factors on SES, and the Wavelet Local Multiple Correlation for analyzing the impact of these factors in different timescales. We applied these approaches to the Heihe River Basin (HRB), an arid inland basin with a 2000-year history in northwest China. The results show that the co-evolution of SES in HRB experienced three phases over the past seventy years, with ecosystem variables exerting a profound influence on regime shifts. Technological progress played a pivotal role in the co-evolution of SES. There is a strong need for early intervention in SES sustainable development, given that human factors influenced evolution over a long time frequency. Our study provides a tool to explicitly direct the co-evolution of SES for more sustainable river basin governance. • Our study quantified the human intervention variables by social science. • We assess the co-evolutionary dynamics of SES and the response to drivers. • Human drivers played a vital role in synergistic development of SES in the long-term frequencies. • Our study provides a tool to explicitly direct the co-evolution of SES for more sustainable river basin governance.