This shows that when the pipeline is half exposed, the clay riverbed is more resistant to the erosion of the river than the riverbed of fine sand and very fine pebbles with a larger particle size.
This shows that in the case of semi-exposed pipes, the sticky riverbed is more resistant to river flushing than the fine sand and very fine pebble riverbeds with larger particle sizes.
This shows that the clay bed is more resistant to river erosion than the fine sand and very fine pebble riverbed with large particle size when the pipeline is semi exposed.