Multiple seismic exploration programs have been conducted in the Ecuadorian Amazon since the 1970s without reusing previously cleared areas for heliports and camps, resulting in unnecessary cumulative deforestation impacts. Walsh Environmental Scientists and Engineers (WALSH) and EnCana have developed a remote sensing technique to eliminate these redundant impacts by accurately identifying historic heliports and camps in mature tropical rainforest for reuse in a 3D seismic exploration program.


Modern seismic exploration programs in a mature tropical rainforest typically utilize a combination of road, river and helicopter access.Many remote exploration areas are restricted to river and helicopter access due to a lack of existing road infrastructure and legal requirements by government regulators not willing to open up new roads, which would accelerate secondary impacts associated with legal and illegal settlement (1).In a roadless seismic operation, heliport and camp clearing typically is the most significant deforestation impact.Seismic activities are often repeated in a particular exploration area due to new data requirements as the seismic acquisition technology has become more sophisticated or a new operator requires additional subsurface data.

Helicopter access to the program is required for the movement of laborers, equipment and material.The impact of these operations is dependent upon the usage and type of access.The smallest impacts tend to be ‘drop zones’ where equipment is lowered through the canopy on a long line.The helicopter pilot will search for a natural opening in the canopy as close as possible to his target and mark the location with GPS. In the majority of cases no vegetation clearing of a drop zone is needed.

A heliport is an area of sufficient area for a helicopter to safely approach and land to discharge laborers or equipment. Heliports vary in size depending on the topography, wind patterns, height of canopy and type of helicopter in use. In heliportable operations heliports are strategically located for operational efficiency and safety in the case of a medi-vac.

Camps in heliportable operations usually result in the greatest impact. They contain living areas, room for support material equipment storage, and a heliport, usually in close proximity to one another.

Historically cleared areas for heliports and camps have naturally regrown quickly with low diversity secondary forest. These areas are difficult to locate or have been ignored by subsequent seismic campaigns resulting in multiple deforestation impacts as new heliports and camps are cleared from the high diversity mature tropical rainforest unnecessarily.A remote sensing technique for determining the location of these historically cleared areas and effective reuse in the Ecuadorian Amazon is described, which has eliminated these redundant deforestation impacts.

Measuring Biodiversity

The area of the seismic program is located largely within Yasuni National Park, with very high animal and plant diversity (Fig. 1).Biologists have measured 2,274 species of trees (2), 567 species of birds (3), 173 species of mammals (4), 105 species of amphibians (5), and 83 species of reptiles (6), 382 species of fish (7), and over 100,000 species of insects (8) in the relatively restricted area of 982,000 hectares.

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