Different urban hydrology studies show that in recent years peri-urban basins have experienced an increase in runoff volumes, in the construction of artificial obstructions, and an increase and overtaking of peak flows due to the decrease in natural areas. This prompted the development of measures such as the hydrological and hydraulic invariance method that allows the operation of the original basins to be recomposed.

In this study, a deterministic, two-dimensional flow precipitation transformation model is applied using PCSWMM Professional 2D to simulate the floodplains using time periods in 2004 and 2020, and then apply the hydrological and hydraulic invariance concept. In addition, four scenarios are proposed to calculate the concentration time to determine its impact on the results of the simulation. To do this, the basin was simulated using four Chicago-type storms with durations equal to the concentration times. The results and conclusions obtained when simulating a basin in the Argentine province of Buenos Aires showed a clear increase in the floodplain was observed associated with the increase in the volume of direct runoff. In addition, this study showed that the drained volumes and reservoirs proposed to apply the invariance increase with the duration of the storm. Finally, the study showed that the anthropic impact not only affects the drained volume, but also modifies the direction and determination of the runoff.

Images of the modeling process

Conduits network

2D Mesh modeling

Reservoir location

Model results