Integrated method for the detection and location of underwater pipelines

Five underwater pipelines with various outer diameters off the south-western coast of Taiwan were investigated with an integrated surveying system which included a dual-frequency side-scan sonar, a high resolution sub-bottom profiler, and a magnetometer. The pipelines consist of one water transport pipeline (with outer diameter of 0.2 m), one crude oil transmission pipeline (1.0 m) and three industrial waste water outflow pipelines (1.5 m, 1.7 m and 1.8 m). This study was aimed at discussing the performance of the integrated surveying system in searching for, monitoring and locating underwater proud and buried pipelines. Specific items associated with this research goal include: route of the pipeline, burial depth of the pipeline, composition and structure of surficial sediments, and artificial objects on and around the pipeline. This research demonstrated and confirmed the need for the multiple sensor approach to supplement an engineering evaluation of underwater pipelines.