Back to Home page Arthur online C.V.
After the Disaster, Before the Phenomenon: A Common Mitigation Plan for Goma, D.R Congo and Gisenyi, Rwanda Mount Nyiragongo is a stratovolcano located 18km north of the city of Goma in the Democratic Republic of Congo. On January 17th, 2002, an earthquake opened fractures through which the lava lake contained in the volcano’s crater escaped and flowed towards the city. A four meters thick, five hundred meters wide lava flow advanced on the city destroying every building on its path (see picture upper right). The volcano being still active, volcanologists predict that lava flows could erupt from fractures opening within the city. Natural phenomena will always happen thus cities located within their range of activity should prevent themselves from their harmful consequences: Disasters are generally due to human causes such as inappropriate urban planning (3) or lack of structural resistance for buildings. The inhabitants of Goma moved back to the city within days or weeks after the catastrophe and rebuild it rebuilt without any consideration for next hazardous events. A mitigation plan for the neighboring cities of Goma and Gisenyi was developped. It is composed of three distinct strategies that takes into account the specificity of the urban, economic and political conditions: 1. Individual protection, construction rules and random barriers across the city. To protect a building from lava flow one needs to know everything about next volcanic events but also ways to build secure structures with appropriate materials and the correct orientation. A model will be proposed for a “lava-proof” building specific to the area. Those buildings-barriers, built across the city, are obstacles that accelerate the cooling process thus slowing down the flow. 2. Large barriers to protect entire zones. The simulations of lava flow helped to identify appropriate locations for large barriers that will channel eventual flows towards the lake. (Drawings on page 2) Those “walls” should be made as lively and accessible as possible on a day to day basis when no eruption occurs, they should also be economically viable. Therefore several programs would be included within the structures themselves such as housings, market places and a hotel. 3. Protection of the main evacuation roads, multiplication of exits towards safe zones. The evacuation of the population was a major problem in 2002. The east-west axes that lead to safe zone should be protected by being lifted from the ground at some points. There should also be more cross boundary zone between the cities.
| Lava Path Simulation done at the INGV
“Two main flows destroyed about 13% of the city, 80% of its economic assets , one third of the airport runway, the housing of 120000 people, caused 470 injuries and 70-100 deaths”(1) “While the lava erupting from the fractures located on the upper flank of the volcano was extremely fluid and thin reaching tens of kilometers per hour, the one erupting from fractures closer to Goma was four meters thick and advanced at a speed of a hundred meters per hour.” (2)
|
