Study on the evolution of ecological environment and irrigation behavior since mulched drip irrigation in Yanqi Basin, Xinjiang

Abstract Analyzing the ecological and behavioral effects of changes in irrigation practices in oases provides valuable insights for water resource management and the sustainable development of oasis agriculture in arid regions. Taking the Yanqi Basin as a case study, this research draws on long-term empirical data and remote sensing information to evaluate the ecological and irrigation behavior effects resulting from shifts in irrigation methods. And explores the deep societal causes behind these behavioral changes. The findings demonstrate: (1). Between 2000 and 2010, the rapid adoption of groundwater extraction and mulched drip irrigation (MDI) technology temporarily alleviated the water supply-demand contradiction. However, from 2010 to 2020, as the adoption of water-saving practices significantly expanded and agricultural irrigation areas grew substantially, the irrigation paradox emerged, where increased efficiency paradoxically led to greater water consumption. (2). From 2000 to 2020, the groundwater table depth in the irrigation district dropped by 8–16 meters, total soluble salt content decreased by 2–5 g/L, and soil salinity decreased by 4–12 g/kg. The proportion of severely salinized and saline soil areas fell from 21.74% in 1999 to 9.75% in 2020. The longstanding salinization issues that had plagued the irrigation district were effectively mitigated with the widespread adoption of MDI. (3). The irrigation district’s vegetation ecological quality index (VEQI) showed a slow but steady upward trend in cultivated areas over the years. In contrast, natural vegetation areas such as forests and grasslands exhibited an initial increase followed by a decline. The trends in VEQI responded well to changes in irrigation practices. (4). The economic benefits driven by water-saving technologies and the expansion of cultivated land are deep societal factors behind the changes in irrigation behavior. These benefits also fostered improvements in users' understanding and awareness of irrigation practices. The shift in irrigation methods in the Yanqi Basin has led to a decline in groundwater levels, an irrigation paradox, and moderate damage to natural vegetation. However, it has had a significant positive impact on improving regional groundwater quality and mitigating soil salinization. Furthermore, it facilitates the further exploration of regional water conservation potential, enhancing the research on the regional water and soil resource management system.