Long-term dynamics of groundwater levels under rice-based irrigation systems in South-East Kazakhstan

Abstract Kazakhstan, located predominantly in an arid climatic zone, relies heavily on irrigation to sustain paddy farming and ensure food security. However, prolonged irrigation practices have substantially altered the groundwater regime, affecting groundwater levels, recharge-discharge patterns and the water-salt balance of soils. These transformations, often difficult to reverse, impact both irrigated lands and adjacent areas, compromising land productivity and the sustainability of rice farming systems. Groundwater dynamics in these areas result from the interplay between natural factors (such as climatic variability, natural drainage and sediment filtration properties) and anthropogenic drivers, including the types and condition of irrigation systems, crop patterns, irrigation scheduling and water management practices. In recent years, climate change, water scarcity, and the degradation of irrigation infrastructure have intensified these processes. This study, based on long-term hydrogeological monitoring data, analyses groundwater regime changes in rice-based irrigation systems of South-East Kazakhstan and evaluates their implications for soil conditions and agricultural productivity. The results reveal heterogeneous spatial and temporal patterns: declining groundwater levels in some areas have alleviated waterlogging and improved soil conditions, while other zones still suffer from waterlogging and soil salinization, limiting crop yields. The identified patterns provide a robust basis for designing adaptive irrigation and groundwater management strategies to enhance the sustainability and resilience of rice farming systems under increasing climatic and hydrological challenges.