Emergy Based Sustainability Scenario Analysis of Oasis Agricultural Systems: A Case Study from Xinjiang, China
How to coordinate arid eco-environmental protection and oasis agricultural development and avoid desertification is a key problem in achieving the sustainable development of oasis human-earth systems. We analyzed the temporal characteristics and overall tendency of an arid oasis agricultural production system in Yining County, China by means of emergy methods and ternary diagrams theory. From 1989–2008, total emergy input and output of the oasis agricultural system in Yining County had a trend of sustainable development. According to the sustainability analysis with emergy indices, the agricultural production systems in Yining County were still at a sustainable status. However, the emergy-based sustainability index (ESI) followed a decreasing trend. Scenario analysis of the sustainability lines based on ternary diagrams showed that both the F (input from economic component) and N (input from nonrenewable resource) leading modes had limitations in the study case. The agricultural production of Yining County should adopt the R leading mode, in which the percentage of non-renewable resources in the local system will be kept roughly unchanged, while the fraction of purchased inputs and renewable resources will be decreased in synchronism. In this way, the contribution from local renewable resources to agricultural production will be increased, and sustainable development ensured.