Abstract: Study on the mechanism of runoff yield on land surface in the alpine meadow-dominated area is helpful for better understanding hydrological processes and rationally planning water resources and protecting ecological environment in the alpine-cold regions. On the basis of field rainfall-runoff experiments, multi-variable driven modules were established for analyzing the regime of land surface flow generation in the alpine meadow area under the influences of different terrain and land cover factors in two rainfall modes (rainstorm and medium-light rainfall). The modules, calibrated with good accuracy, reflected the general characteristics of alpine meadow runoff under the two rainfall types. Due to the large storage capacity of the soil-planting system, surface runoff in the alpine meadow mainly occurred in the rainstorm mode, whereas in the medium-light rainfall mode, the amount of surface runoff was small in general. The application of the models showed that after the degradation of the meadow, the infiltration during both rainstorm and medium-light rainfall attenuated. Rainfall infiltration in the degraded meadow in rainstorm mode dropped by about 12% compared with that in largely-covered meadow, and the infiltration in medium-light rainfall mode decreased by about 3%.

Key words: alpine meadow, land surface runoff yield, field experiment of rainfall-runoff processes, rainfall mode, rainfall infiltration