During periods of high-water-level operation in Miyun Reservoir

pollution by surface floating debris along the shoreline becomes severe

posing threats to water quality security and the ecological functions of the reservoir. Focusing on the transport patterns of floating debris

this study improved prevention and control measures for surface debris under highwater-level operating conditions. A multi-factor analysis revealed a pronounced regional differentiation in debris transport jointly controlled by wind-driven currents and river type currents and channelized flow. In the southern reservoir area

wind forcing predominates

driving floating debris toward the northeastern reservoir bays where it accumulates. In the northern reservoir area

terrain sheltering weakens wind effects

and debris transport is dominated by flow conveyance along the ri

ver channels. Based on these transport patterns

a targeted three-level prevention and control system was established. First

for large-volume debris entering from northern inflow tributaries

a primary source-interception system consisting of V-shaped trash-blocking booms and ecological ditches was deployed. Second

along the wind-driven transport pathways and accumulation zones in the southern reservoir area

adaptive double-pontoon floating barriers were arranged to guide and concentrate debris during transport. Third

a fine filtration screen was installed upstream of the water intake to ensure terminal water quality safety. After implementation of these measures

the system achieved remarkable results: the average monthly removal volume increased from 0. 90 million m

3

to 1. 55 million m

3

removal efficiency exceeded 80%

resource recovery benefits were substantial

and effluent COD and ammonia nitrogen consistently met the relevant standards. The results demonstrate that a three-level prevention and control system designed according to floating-debris transport patterns can substantially improve the efficiency and precision of debris management

and provides a pattern-based

hierarchical

and coordinated solution for floating-debris control in similar water bodies.