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• Flood season and autumn are the leading periods of annual runoff reduction. • The underlying surface change is the dominant factor for annual runoff change. • Climate change dominates runoff changes in flood season, summer and autumn. • Underlying surface dominates runoff changes in non-flood season, spring and winter. Accurately understanding the intra-annual variation in runoff evolution attribution is essential for basin-scale water resources management. In this study, the runoff in the Yellow River source area was divided into two intra-annual time scales: flood season, non-flood season and spring, summer, autumn and winter, and the sensitivity and attribution differences of runoff changes in the Yellow River source area at different intra-annual time scales were quantitatively assessed based on the time-varying Budyko framework. Results show that the runoff in the Yellow River source area decreases during the flood season and spring, summer and autumn, and increases during the non-flood season and winter from 1960 to 2020, with an insignificant decreasing trend in annual runoff. Flood season and autumn runoff changes are the main reasons for the reduction in annual runoff. Runoff in the Yellow River source area is most sensitive to the underlying surface such as vegetation and soil freeze–thaw change, and in terms of climate change, non-flood season and autumn runoff is more sensitive to changes in precipitation, while flood season and summer runoff is more sensitive to changes in potential evaporation. The underlying surface change is the dominant factor for annual runoff change. And for the intra-annual runoff change, the non-flood season, spring and winter runoff in the Yellow River source area is dominated by the underlying surface change, and flood season, summer and autumn runoff is dominated by the climate change. These findings can provide theoretical support for the scientific response to environmental change and the enhancement of water conservation capacity in the Yellow River source area. [ABSTRACT FROM AUTHOR]

The precipitation rate dominates meteoric 10Be in soils rather than soil dynamics, and the relation of the two is indicated in a binomial way with positive correlation in low precipitation regions (<1200 mm per year) and negative in high precipitation regions (>1200 mm per year). • 10Be concentrations in topsoil are influenced by precipitation and soil dynamics. • Precipitation shows more control on 10Be using PCA and correlation analysis. • 10Be concentrations-precipitation shows different trends in dry and humid regions. • Underlying surface affects 10Be without changing 10Be-precipitation relationships. Meteoric beryllium-10 (10Be) is commonly used as a proxy of landscape dynamics (erosion and sedimentation rates) and soil development. Soil represents the first-stage reservoir of meteoric 10Be, and variability in the concentration of the isotope in soils may be affected by soil properties and atmospheric deposition. Although many investigations have targeted this issue, there are still problems in estimating the atmospheric input of the isotope in different soil environments. Here, we used 10Be data measured in soils distributed across China to explore the potential influence of meteorological and pedological conditions on the isotope concentration and related applications. In addition, to determine the mechanisms controlling 10Be concentrations in topsoil on a regional scale, the soil samples were sub-divided into 18 different catchments according to fluvial systems. The results indicated that there were significant negative correlations between precipitation and the soil 10Be concentration in high-precipitation regions (>1200 mm·y−1) and significant positive correlations for soils in low precipitation regions (<1200 mm·y−1). The data also revealed that precipitation is the most important variable controlling the 10Be concentration in soils of China when compared with the effects of soil properties such as grain size, mineralogy, pH, and cation exchange capacity. Land use and soil erosion may have limited impacts on the distribution of 10Be in soils. [ABSTRACT FROM AUTHOR]