This poject deals with the long range propagation of strong blast waves in a real environment resulting from the blasting of an ammunition, from an accident or from a terrorist attack. This project has got applications both in the public domain and in the military perimeter. This is why it is submitted to ASTRID. Although a number of progresses and breakthrough appeared along the last few decades as for the understanding and modelling of the propagation of blast waves, present experience gained from analysis of accidents reveals that the overpressure field might be severely underestimated using today state of art in this domain. Some scarse data suggest that the topography in the vicinity of the explosion, the absorptivity of the ground and the heterogeneities of the atmosphere may explain this. Yet, clear evidence and undisputable data are lacking. The purpose of PROLONGE is to clarify the real incidence of the aforementioned parameters and to be able to model them using available numerical simulation technologies. To this aim, the consortium comprises experts in numerical simulations (CEA), experts in blasts waves and instrumentation (INERIS) and experts in performing "heavy" blasting using large amounts (up to 1000 kg) of explosive in their daily activity (NOBELCLAD Europe SA) in an open and natural environment. The main deliverables are : -physical and numerical models to account for the role of the topography, the absorptivity of the ground and the heterogeneities of the atmosphere -"fast" operating numerical codes and engineering methods incoroporating these models - a database of the tests performed to be delivered to the experts of this scientific area