Generation of multi-temporal JERS-1 SAR mosaics over the Manaus-Coari-Urucu Region, Western Amazonia, Brazil

Studies conducted by Petrobras (the Brazilian national oil company) in Western Amazonia indicate a high demand for petroleum in the region. This fact encouraged Petrobras to build a pipeline that transports 60 thousand barrels of oil per day from the Urucu oil and gas province to the Solimoes terminal north of the city of Coari. This oil is then shipped to another terminal in Manaus. The water level changes between dry and wet seasons attain a difference up to 14 meters in the surroundings of Coari city. The strong seasonal character of the Amazonian climate gives rise to four distinct scenarios in the annual hydrological cycle: low water, high water, receding water, and rising water. These scenarios constitute the main reference for the definition of oil spill response planning by Petrobras. The systematic coverage of JERS-1 SAR images obtained in Western and Central Amazonia between October 1995 and November 1996 allowed the construction of mosaics contemplating these four seasonal scenarios, and therefore improving information about oil spill environmental sensitivity. Twenty-two (22) images per seasonal scenario were used to build the mosaics, which were then classified using the unsupervised semivariogram textural classifier (USTC). Cover types identified using USTC included flooded forest, upland forest and water. These four seasonal mosaics were manipulated using GIS technology to: (1) serve as a spatial framework to environmental studies, such as genetics and distribution offish species, malaria, social-economics, macrophyte distribution, water chemistry, among others; (2) design Petrobras´ contingency plans and guide simulated oil spill exercises in the fluvial environment; (3) model water hydrodynamics over the flooded forest; (4) define the route of the Coari-Manaus pipeline avoiding oil sensitive and environmentally protected areas. The information derived from JERS-1 SAR data is straightforward to interpret and constitutes an operational representation in the cartographic space of oil spill sensitivity classes conceived by Petrobras.