Regional water resource security evaluation in the loess plateau area based on the emergy ecological footprint: a case study of Zhangjiachuan Hui Autonomous County, China

Water security is a critical global issue, particularly in arid and semi-arid regions like China’s Loess Plateau, where water scarcity threatens sustainable development. To address this issue, this study developed an improved emergy ecological footprint model to systematically evaluate the water resource security of Zhangjiachuan Hui Autonomous County from 2014 to 2023. The model integrated emergy theory and ecological footprint analysis to quantify the water resources emergy ecological carrying capacity (WEEC), emergy ecological footprint (WEEF), and key indicators including ecological surplus/deficit (WEES/WEED), ecological tension index (WETI), and sustainable utilization index (WSUI). The results reveal a concerning transition from ecological surplus (average WEES 0.6 hm2/cap during 2014 − 2022) to deficit (WEED − 0.8 hm2/cap in 2023), with WETI exceeding the insecure threshold (1.5) and WSUI indicating severe unsustainability (0.6) in drought years. These trends are driven by two synergistic mechanisms: (a) ecological constraints, where 85% precipitation concentration (May–October) and loess hydrogeology cause 60% interannual WEEC variability (1.5 − 2.4 hm2/cap), and (b) socioeconomic pressures, with WEEF growing 7.7% annually due to increases of 178% in livestock and of 62% in orchards. Based on these findings, this study proposes an integrated management framework featuring precision agriculture, circular livestock systems, and loess-specific rainwater harvesting. This study provides a novel framework to be used as an evaluation tool and a source of policy insights for the water resource security evaluation and sustainable utilization of regional water resources.