NEO has recently won a new assignment to analyse the changes to the ground level above the gas transport pipelines for Gasunie. For this purpose, the latest version of the General Height Database of the Netherlands, the AHN4, is used, among other things. The monitoring of changes in depth is important for monitoring the undisturbed location of the pipelines.
Gasunie transports natural gas, green gas and hydrogen using gas transmission pipelines. One aspect of ensuring safe location and controlling risks is checking the coverage of gas transport pipelines. The cover is the difference between ground level and the depth of the pipeline (which is known) and is an important parameter in the assessment of risks to the pipeline and the surrounding area, such as external safety. Coverage is calculated by comparing the measured depth of the pipelines with recent ground level data.
The value of the ground level is determined by the Algemeen Hoogtebestand Nederland (AHN4), supplemented by Gasunie surveying field measurements. The quality of AHN4 also offers the possibility to determine the profile of dry ditches. This will reduce the amount of additional field measurements.
Monitoring coverage in this way provides quick insight into changes in ground level over time over the long pipeline routes, and enables Gasunie to work in a risk-driven way and shape pipeline management efficiently.
