In water management, which cycle describes the movement of water through the atmosphere, surface, and subsurface?

• A. Hydrological cycle
• B. Oxygen cycle
• C. Carbon cycle
• D. Nitrogen cycle

Answer: (A)

Think of water’s ongoing journey through every part of the landscape. Water evaporates from oceans, lakes, and soil and also exits through plants (transpiration), rising into the atmosphere as vapor. In the sky, that vapor cools and condenses into clouds, leading to precipitation that returns water to the surface. From there, water may run off across the land, flow into rivers and lakes, or infiltrate the soil to recharge groundwater. Groundwater can move slowly through rocks and soils and later feed springs or return to surface water, where the cycle begins again. This describes the movement of water through the atmosphere, surface, and subsurface—the hydrological cycle.

Other cycles involve different elements and processes, such as the oxygen cycle (movement of oxygen between air, water, and living organisms), the carbon cycle (carbon dioxide and related forms cycling through the atmosphere, biosphere, oceans, and rocks), and the nitrogen cycle (nitrogen transformations in soils and organisms). But none focus on the continuous movement of water through those interconnected reservoirs like the hydrological cycle does.