Sustainability assessment of the Liaohe Estuary wetland based on emergy analysis
Fangli Su, Haisheng Liu, Dan Zhu, Lifeng Li, Tieliang Wang
Abstract
The sustainability of wetlands, as an ecological system, is a key indicator of its system stability. The sustainability evaluation of wetlands is the basis of management and research. In this study, the ecosystem value and sustainability of the Liaohe Estuary Wetland were evaluated by using emergy analysis and emergy indicators. The results showed that the total input emergy of the Liaohe Estuary Wetland was 307.12 × 1018 sej, included renewable resources 74.83 × 1018 sej, nonrenewable resources 103.02 × 1018 sej and purchased resources 129.27 × 1018 sej. The final emergy value was 332.9 × 1018 sej, and the main part was the outputs of 290.28 × 1018 sej, accounting for 87.19% of the total emergy export. The intermediate service value emergy was 1980.99 × 1018 sej, of which 90.72% was occupied by biodiversity maintenance value. For the sustainability evaluation of the Liaohe Estuary Wetland, the emergy yield ratio (EYR) was 2.38, the environment loading ratio (ELR) was 3.10, and the emergy sustainability indicator (ESI) was 0.77, the development of the study area was in an unsustainable state. A new index of intermediate-final conversion ratio (EIFC) was established to evaluate the conversion proportion from the intermediate value to the final value. EIFC was 1.18%, which showed that the service potential of wetlands was huge.