Under climate change, river ecological base flow becomes particularly critical for the health and stability of inland river ecosystems in arid regions. Taking three typical seasonal inland rivers, including the Kriya River, the Niya River, and the Qarqan River, all on the northern slope of the Kunlun Mountains, as research objects, meteorological data from 1958 to 2019 and hydrological data from 1978 to 2014 were selected to analyze the characteristics of ecological base flow under climate change. The results show that in the past 60 years, the temperature in the Kriya River, Niya River, and Qarqan River basins has warmed at rates of 0.235 °C•(10a)⁻¹, 0.223 °C•(10a)⁻¹, and 0.177 °C•(10a)⁻¹, respectively, while the precipitation has increased at the rates of 0.88 mm•(10a)⁻¹, 3.90 mm•(10a)⁻¹, and 7.92 mm•(10a)⁻¹. The Tennant method was determined as the best algorithm for ecological base flow of inland rivers in arid regions. The interannual maximum values of ecological base flow all occurred in 2010, with three rivers increasing by 5.098 m³·s⁻¹, 2.416 m³·s⁻¹, and 11.343 m³·s⁻¹ respectively, and the regional average increasing by 6.286 m³·s⁻¹. The maximum ecological base flow within the year is in July, and the minimum value is in January, with a high proportion of the flood season. The monthly ecological base flow of rivers has a strong correlation with the monthly temperature and precipitation, with the strongest correlation in the Qarqan River basin and the correlation coefficients of 0.876 and 0.917. We propose ecological base flow guarantee objectives for the three rivers during the dry season, and clarify that the flood season is the key point of ecological base flow guarantee. The guarantee objectives are 0.974 m³·s⁻¹, 0.154 m³·s⁻¹, and 2.167 m³·s⁻¹, for the three rivers, respectively. Our research results can provide scientific reference for the management and regulation of water resources and ecological protection of the northern slope of the Kunlun Mountains.

Rain-on-snow (ROS) events profoundly influence mixed rain–snow flooding and the water resource cycle. However, current research regarding ROS events remains predominantly reliant on existing datasets, lacking detailed controlled experiments under variable conditions. This study employed control variables and an orthogonal experimental design to conduct laboratory-controlled experiments simulating ROS events with different temperatures, rainfall intensities, and rainfall durations. Observations and analyses were performed on the snowmelt volumes during and after events. The results indicate that ROS events significantly accelerate snowmelt rates and increase total snowmelt volume. Under low-intensity ROS, snowmelt volume exhibits greater sensitivity to temperature changes. A temperature threshold exists between 2 °C and 6 °C; beyond this threshold, the melting rate accelerates and ablation volume increases. Under high-intensity ROS, rainwater becomes the dominant factor driving snowpack ablation. When rainfall intensity exceeds 60 mm·h⁻¹, it triggers a sharp increase in snowmelt volume. Concurrently, following an ROS event, snowpacks subjected to low-intensity rainfall exhibit a stronger rainwater retention capacity, an effect that becomes more pronounced at lower temperatures. Additionally, snowmelt volume increases with prolonged rainfall duration, with the increment in snowmelt volume attributable to extended rainfall time being greater under weaker rainfall intensities. These findings provide a scientific reference for better understanding ROS-related disasters mechanisms.