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An important part of successful pipeline route selection includes the identification of geologic hazards and man-made (anthropogenic) features along any proposed route. Fugro William Lettis & Associates, Inc. (Fugro WLA) was contracted to provide a preferred crude oil transmission pipeline route between the Agadem oil field and the Zinder refinery in south-central Niger. The development of the 460-km long, 500-meter wide corridor involved the use of new geologic mapping and a digital elevation model (DEM) derived from Satellite Pour l'Observation de la Terre (SPOT) remotely-sensed imagery and SPOT High Resolution Stereo (HRS), respectively. The base geologic, anthropogenic and DEM data were provided by Fugro NPA Ltd. (Fugro NPA) and augmented with additional mapping by Fugro WLA.

The area of the proposed pipeline route covers varying geologic conditions such as active and relict sand dunes, bedrock outcrops and escarpments, wadis and areas of recent erosion. Anthropogenic features included reservoirs, roads, towns and settlements, agricultural areas and oases. Our study found significant height differences between the dunes and evidence for varying dune activity. Selection of the optimal pipeline route required minimization of total elevation change and exposure to geologic hazards and existing anthropogenic development while obtaining the safest, most direct and economic route between the oil field and refinery. Using a geographic information system (GIS) the digitally-mapped geologic and anthropogenic features and elevation-derived parameters were assigned a relative risk ranking surface. Next, a cumulative cost distance surface and a cost path surface were created between the oil field and the refinery. Lastly, using GIS we developed a least-cost pipeline route option from the cost path surface.