Hydrogeology

The Gran Lima aquifer consists of Quaternary alluvial deposits of Rimac and Chillon  valleys. These deposits are characterized by the presence of boulders, gravel,  sand and clay interspersed in layers and/or mixed. Another aspect is the  presence of groundwater level that changes  during the project area. In particular, the groundwater is located near the  harbor zone in correspondence to the first part of line 2 and to the total of line  4.

Tectonics and Seismicity

Perù is located on the east coast of the Pacific in so-called “Cinturon de  Fuego del Pacifico” area that due to the interaction between the South America  plate and Nazca plate, which generates a subduction zone near the Perù coast,  represents one of the most active  earthquake zones in the world. For this reason, a study of seismic risk of the  project area was carried out in order to evaluate the correct seismic  parameters. This study is based on seismic hazard determination which is  defined as the exceedance probability of a determinate ground motion intensity  value due to an earthquake in a given location and during a defined time  period. According to this study (with deterministic and probabilistic methods)  and taking into account the spatial variability of the seismic action, the  maximum value of the peak ground acceleration equal to 0.40 g has been  obtained. For the evaluation of seismic design parameters five representative  zones, each having different geophysical and geological characteristics, were considered (Table B).