Rainfall-runoff storage-infiltration effect of LUCC in highly urbanized region on a catchment's scale: Shanghai urban green space system as an example

Land use and cover change (LUCC) caused by rapid urbanization had remarkable influence on urban surface hydrological processes. The urban green space as one main penetrative underlying surface type, presents a strong storage-infiltration effect. According to LUCC, rainfall and runoff data collected from highly urbanized area in central Shanghai in 2000 and 2003, the hydrological processes of LUCC with areas of 2. 60km² and 2.77km² adjacent catchments, respectively were analyzed. The results exhibited the green system, in a highly urbanized region on a small catchment's scale, had obvious storage-infiltration effects to eliminate total amount of rainfall-runoff, and to extend time-lag of runoff flood peak Case study of two urban catchments with a similar boundary condition, 39.13% and 27.36% area of green spaces respectively, showed that 10% area difference between green systems, and the differences among green structure, cover plants and soil types could cause (i) 0.3 difference for annual runoff coefficient between two catchments; (ii) 20min extension for runoff peak in the process of 42.8mm precipitation within 24h; (iii) 0.1 runoff coefficient elimination beyond 270mm storm runoff process within 24 h.