Identification of priority protected areas in Yellow River Basin and detection of key factors for its optimal management based on multi-scenario trade-off of ecosystem services

Identifying priority protected areas based on ecosystem services (ESs) is a key step to realize the integrated allocation and optimal management of ecosystems in Yellow River Basin (YRB). However, balance the trade-offs between ESs is still a challenge in protected area planning. In this study, based on CASA, InVEST, RWEQ, and RUSLE, we quantified the spatial and temporal fluctuations in carbon sequestration, water yield, sandstorm fixation, and soil conservation in the YRB from 2000 to 2018. Then we introduced ordered weighted averaging (OWA) operator to simulate multiple scenarios, and identified priority protected areas at the basis of ESs trade-offs. Finally, the dominant influencing factors in the management of ESs in priority protected areas were identified by the Geo-Detector. Our results indicate that: (1) From 2000 to 2018, carbon sequestration, water yield and soil conservation in the YRB increased by 37.47%, 53.99% and 86.04% respectively, while sandstorm fixation decreased by 9.55%. Carbon sequestration, water yield and soil conservation all present a spatial pattern of “high in the southwest and low in the northwest”, while the high value areas for sandstorm fixation are concentrated in the northwest and east of the YRB. (2) The location and conservation effectiveness of protected areas differ across multiple decision-making scenarios, and S3, with optimal protection effectiveness, is chosen as the priority protection scenario. The selected priority protected areas are primarily located in the Yellow River source region, the Loess Plateau, and portions of the lower reaches of the YRB, covering a total area of 161.747 × 103 km2. Under this scenario, the conservation efficiency of carbon sequestration, water yield, sandstorm fixation and soil conservation are 1.371, 1.455, 1.644 and 2.371, respectively, which can realize the efficient protection of multiple ESs at the same time. (3) In priority protected areas, natural environmental factors explain ES to a greater extent than factors of human activity. NDVI and precipitation are the main factors influencing carbon sequestration, water yield and sandstorm fixation, while slope has the strongest influence on soil conservation. The interaction between the factors will significantly enhance the explanatory power of the driving factors. Our findings can provide theoretical support to the sustainable management of ecosystems and the optimization of the ecological barrier function in the Yellow River Basin.