This paper shows results related to the monitoring of an extensive green roof (GR), the development of a rainfall-runoff model and the analysis of large-scale impact of GR by modelling different basins. Large-scale modelling (basins ranging from 0.03 ha to several square kilometers) showed that the widespread use of GRs reduced peak flows (volumes) around 57% (48%) at source and 38% (32%) at the basin scale. These findings show that GR is a good option to cope with urbanization impact.

Results showed an intensification of extreme events in recent years in Northeastern (NE) Brazil , especially in shorter duration rainfall (less than 12 h). Hourly rainfall is bigger in almost all the NE region, but especially in littoral and Northern portion, however, 12 and 24h rainfall exhibit increases in the North, but, lower values in the Southern half of the region in concordance with flood changes reported other authors.

Results show the large potential of a simple general IDF equation as Bell’s (1969) equation to describe and understand the spatial and temporal distribution of extreme hydrological events involving heavy rainfall in Southern Brazil, when associated with TRMM estimate. This is important for a region with data scarcity, especially for shorter durations rainfall