| “CHNC” | Space | Intracoupling | Interaction between subsystems, as well as the elements within the particular areal system. |         | Statistics, coupling degree, coupling coordination degree, etc. | Omitted |
| Telecoupling | Interaction between humans and nature in different remote areal systems, or in different spatial scales. Two categories: Multi- regional telecoupling (MRTC) and multi- scale telecoupling (MSTC). | Multi-region input-output model, spatial Durbin model, hierarchical spatial autoregressive model, network analysis, material flow analysis, energy flow analysis, etc. | MRTC: Water diversion, industry transfer, tourism, international trade, technology transfer, investment; MSTC: Local responses to climate change, global diffusion of local pollution |
| Time | Syncoupling | Interaction effect between humans and nature occurring in a similar time section. | Statistics, coupling degree, coupling coordination degree, time series analysis, etc. | Omitted |
| Lagcoupling | Interaction and feedback between humans and nature in different time periods; the causal chain has relative long time intervals. | Time-delay model, dynamic general equilibrium model, multi-level temporal autoregressive modeling, etc. | The time lag effect of environmental investment on local eco-environment; the 1.5 C global warming target in the Paris Agreement has important effect for current policy. |
| Appear-ance | Apparent coupling | Direct interaction between subsystems; elements within the CHANS and causal chain are A→B | Correlations analysis, linear regression analysis, coupling degree, coupling coordination degree, etc. | Omitted |
| Hidden coupling | Interaction between elements or systems is not direct, but works indirectly through a mediator or through an implied system or element, and the causal chain is A→C→B or A(C)→B. | Mediating effects model, multi-region input-output model, environmental footprint, life cycle assessment, etc. | A→C→B: Urbanization has indirect effects on carbon emissions by influencing the structure and intensity of energy consumption; A(C)→B: Pollutants, carbon emissions, virtual water hidden in international trade. |
| Organization | Intra- organizational coupling | Interaction between humans and nature in a particular organization. | Statistics, game theory, etc. | Omitted |
| Inter-organizational coupling | Complex interest game to tradeoff human development and environment between different organizations and stakeholders. | Game theory, multi-agent modeling, complex adaptive systems theory, multicenter self-organization theory, complex networks, big data analysis, etc. | Stakeholders such as government, farmers, medias and NGOs have different roles and behavioral responses in ecological compensation. |
