White water occurs in the upper course of a river when the gradient and obstacles disturb the ow of water, causing it to churn and create bubbles. These bubbles reflect back much of the light that hits them, making the water appear white. Whether a river flows smoothly often depends on its speed, and the steeper the riverbed, the faster the water will ow. The combination of fast- owing water and obstacles like rocks causes the flow?to become turbulent, with unpredictable variation in the speed and direction of the water. This creates a variety of features in the river. Where water doubles back on itself, pockets filled with bubbles open up; these provide much less buoyancy and feel like ‘holes’. Objects lodged in the river can act as strainers, allowing water to pass through, but blocking larger debris. In areas where the water moves rapidly, it wears away at the surface of rocks underneath, creating undercuts. The challenges of navigating the features of white-water rapids – whether jutting rocks or whirlpools – attract kayakers and rafters every year.
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Subrata
White water occurs in the upper course of a river when the gradient and obstacles disturb the ow of water, causing it to churn and create bubbles. These bubbles reflect back much of the light that hits them, making the water appear white. Whether a river flows smoothly often depends on its speed, and the steeper the riverbed, the faster the water will ow. The combination of fast- owing water and obstacles like rocks causes the flow?to become turbulent, with unpredictable variation in the speed and direction of the water. This creates a variety of features in the river. Where water doubles back on itself, pockets filled with bubbles open up; these provide much less buoyancy and feel like ‘holes’. Objects lodged in the river can act as strainers, allowing water to pass through, but blocking larger debris. In areas where the water moves rapidly, it wears away at the surface of rocks underneath, creating undercuts. The challenges of navigating the features of white-water rapids – whether jutting rocks or whirlpools – attract kayakers and rafters every year.