The scientists tested a new method to measure how sediment moves in steep channels with big rocks. They did experiments in a lab with different slopes and sizes of sediment. They found a way to predict how much sediment will move based on the slope. Their results matched some existing models, especially for really steep slopes. This means the new method can be used to study how sediment moves in different types of channels, not just with round rocks of the same size. They also made a simple model to estimate sediment movement on slopes up to 5%.