Transport and Distribution of Nutrients in the Runoff System of Urban Backfilled Soil

Runoff pollution have become a serious issue in terms of water pollution in porous areas, especially in urban backfilled soil. The transport and distribution of runoff water and nutrients in the surface runoff and the subsurface runoff of backfilled soil runoff systems are determined using simulated rainfall and the results indicate that the flow patterns of runoff are different from those of surface runoff and subsurface runoff. The rate of surface runoff flow increases in the beginning and reaches a stable state with a delay of 10 min to rainfall, while the flow rate of subsurface runoff is consistent during the whole runoff period. Most of the pollutants (90% of total suspended solids, 88% of total phosphorus, and 78% of total nitrogen) are carried in the surface runoff, which directly results in polluting the surface‐receiving water. The results of the present study will provide information related to the management of runoff pollution in the backfilled soil runoff system.