Students who lived near a desert area in Saudi Arabia, were investigating the effects of river processes in a valley called a wadi. Although there was no river flowing in the valley when the students were doing their fieldwork, they could see some evidence of the work of the river when it had flowed through the valley. The students investigated the following hypotheses: Hypothesis 1: The gradient of the valley floor decreases downstream. Hypothesis 2: The river's bedload becomes smaller and more rounded downstream.