Background Miyun Reservoir is the most important drinking water source in Beijing. It is of great significance to study the characteristics of runoff and sediment yield on slopes and their responses to rainfall for water source protection.

Methods Based on field observations of rainfall, runoff, and sediment yield on 10 runoff plots with different land use types in Shixia Watershed, the upstream of the Miyun Reservoir, during 2014-2019, the characteristics of runoff and sediment yield on slopes and their responses to rainfall of land use types were studied.

Results 1) The engineering measures such as fish-scale pits, horizontal strips and terraces had significant benefits in reducing runoff and sediment yields. The sediment reduction rate by chestnut forests with large horizontal strips was 94.35%. Biological measures had better ability to regulate runoff and sediment, and the peak reduction rates of runoff and sediment reached 100%. The runoff and sediment yield decreased with increasing vegetation coverage. The combination of biological and engineering measures was more effective. 2) Both runoff generation and sediment yield showed positively significant linear relationships with rainfall amount P and maximum 60 minutes rain intensity I₆₀, with correlation coefficients of 0.85 and 0.90. 3) The implemented engineering measures or increased vegetation coverage weakened the impact of I₆₀ on runoff and sediment yields on the slopes. The runoff and sediment yield from these runoff plots were significantly affected by P, while they were not significantly affected by I₆₀. The runoff amounts from the plots with low-coverage corn and from the bare land were significantly affected by P and I₆₀, but there were no significant relations between sediment yield and P and I₆₀. 4) The sediment yield increased with increasing runoff rate, with the correlation coefficient of 0.80. Soil and water conservation measures decreased sediment yield by reducing runoff and sediment concentration. The biological measures have better sediment reduction benefits.

Conculsions Reasonable arrangement of soil and water conservation measures may effectively reduce soil erosion and reduce the impact of rainfall intensity on runoff and sediment yield on slopes in the upstream of the Miyun Reservoir. This study may provide a scientific basis for the treatment of sand production on the slopes of Beijing mountainous areas.