Adaptability zoning method for photovoltaic base construction in Qilian County, Qinghai Province of China based on ecological sensitivity

The ecologically vulnerable regions in Northwest China were identified as key potential areas for renewable energy development. The synergistic advancement between establishing new energy bases and implementing comprehensive land consolidation was considered a crucial strategy for promoting high-quality development in these fragile ecosystems. This study, which took Qilian County in Qinghai Province as the research area, developed an ecological sensitivity assessment model based on topographic, soil, and ecological factors. A suitability evaluation model for photovoltaic (PV) base construction was also established, incorporating energy resources, infrastructure conditions, and landscape structure. A systematic analysis was conducted to assess the regional ecological sensitivity, the suitability for PV base construction, as well as the coordinated development level of the two aspects. Based on the coupling coordination degree model, the photovoltaic base construction type areas were classified to promote the layout of the new energy industry and the comprehensive land consolidation in a coordinated manner. The findings revealed that: 1) The overall ecological sensitivity in Qilian County was relatively high, showing a general pattern of "higher in the west and lower in the east." Townships such as Yanglong and Yeniugou exhibited particularly high sensitivity. Conversely, the suitability for PV base construction demonstrated a "high in the north and south, low in the center" pattern, with higher suitability concentrated in towns like Mole and Ebao. 2) Using the coupling coordination degree model, Qilian County was categorized into four adaptive type areas. The high-quality coordination zone (2734.70 km²), located in areas including Mole Town and Arong Township, was prioritized for PV base development, where the "pastoral-photovoltaic complementary model" could be developed, and ecological protection and restoration work should have been emphasized before and after construction. The good coordination zone (2690.57 km²), found in parts of Yanglong and Yeniugou Townships, where the "pastoral-photovoltaic complementary model" and "photovoltaic + agricultural model" could be developed, and the regional ecological environment was generally in good condition; however, pollution of the water areas within the basin should be prevented and soil and water conservation work should be done well. The moderate coordination zone (1150.54 km²), distributed across parts of Yanglong Township and Mole Town, had high ecological sensitivity and significant constraints for solar energy exploitation, necessitating a priority on ecological protection and only moderate PV development. The barely coordinated zone (374.18 km²), located in areas like Yanglong Township, was strictly limited for development; Priority should be given to natural restoration, supplemented by necessary ecological restoration projects in a timely manner. This study provided a methodological framework for integrating new energy industry development with land restoration efforts in ecologically vulnerable regions.