How to Guarantee the Sustainability of the Wind Prevention and Sand Fixation Service: An Ecosystem Service Flow Perspective

Assessing ecosystem services (ESs) is essential for sustainable development. Ecosystem service flow (ESF) emphasizes the recognition of real ESs beneficiary areas from the perspective of human welfare and establishes a spatiotemporal path between service supply areas (SSAs) and service beneficiary areas (SBAs) to better reflect the relationship between ESs and human welfare, which is conducive to recognize how to guarantee the sustainable supply of ESs. This study simulated the spatiotemporal patterns and flow trajectories of the wind prevention and sand fixation (WPSF) service in Yanchi County based on the Revised Wind Erosion Equation (RWEQ) and the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model, respectively, and constructed an analysis framework for the sustainability of WPSF service from the perspective of ESF. The results indicated that the amount of wind erosion prevented in Yanchi County was 3.71 × 109 kg in 2010 and 0.08 × 109 kg in 2015, with average retention rates of 83.40% and 78.11% and WPSF service values of 479.46 million CNY (Chinese currency; as of 18 July 2018, 6.702 RMB = US $1) and 10.22 million CNY, respectively. The flow trajectories of the WPSF service mostly extended to East Asia, and the densities decreased as the transmission distance increased. The estimated areas of the SBAs of WPSF service in Yanchi County were 1153.2 × 104 km2 in 2010 and 397.2 × 104 km2 in 2015. The grid cells through which many (≥10%) of the trajectories passed were mainly situated in the central part of northern China. The spatiotemporal distribution patterns and flow rates of the physical and value flows of the WPSF service were the same. The SBAs within China accounted for 71.11% in 2010 and 91.32% in 2015, and both maximums occurred in Shaanxi Province. In this research, we identified the actual beneficiaries according to the spatiotemporal distribution of physical and value flows. There were mismatches between the value flow and eco-compensation flow, which was unsustainable. This work can serve as an effective and valid reference for the ecological compensation standard and the formulation of ecological protection measures, which is conducive to regional sustainable development and human welfare