The Historic Sanctuary of Machupicchu was located in the Eastern Cordillera of southern Peru, surrounded to the north by the snow-capped Verónica (5750 masl) and Bonanta (5024 masl) and, to the south, by Salcantay (6264 masl) and Humantay (5459 masl) . The Inca citadel is located at 2450 masl, 500 m above the Urubamba river, which cuts the mountain range and forms a gorge with a jungle-like climate. Geology, with granite outcrops and stacked granite blocks, forms a landscape of granite chaos, on which the Inca citadel of Machupicchu was built.
Throughout these pages, the geodynamic phenomena that affect the Inca citadel of Machupicchu – such as settlements, suffusion, surface erosion, landslides, rock falls, and surface landslides – are painstakingly described. During the Inca occupation, the platforms with drainage systems and the constructions with roofs allowed an effective evacuation of the abundant rainwater; However, this is not the case currently, since the constructions do not have a roof and a large part of the drains do not work, generating infiltrations, superficial erosion, suffusion, settlements, etc. Detailed geological surveys and specific studies in various areas (ensembles) make it possible to make recommendations for the adequate evacuation of rainwater and to avoid infiltration or surface erosion, through drains and waterproof floors.
Following publications and news that generated alarm at the international level by announcing that the Inca citadel of Machupicchu was at risk of collapse due to a major landslide, several international and Peruvian missions conducted investigations to evaluate these claims.
External geodynamic evaluations of the Traditional “Inca Trail” and the “Sacred Path or short path” have revealed landslides, floods, rock falls, landslides, soil creep, settlements, surface erosion, river erosion, as well as sufusion, events that are related to the effects of water and the intervention of man. These phenomena cause the partial or total destruction of some parts of the road. Likewise, the negative environmental impacts that affect the Traditional Inca Trail and the Inca city of Machupicchu have been identified. Then, with the use of cause-effect matrices, the environmental impact assessment of this path has been carried out by sections, with emphasis on geodynamic phenomena and anthropic activities that affect the geo-biophysical and sociocultural environment and, finally, the measures are presented mitigation and prevention to protect this Inca heritage.
