Which of the following best defines the term 'surface water'?

The term 'surface water' specifically refers to water that is found on the Earth's surface in bodies such as rivers, lakes, and streams. This type of water is easily accessible and plays a critical role in the ecosystem, providing habitats for aquatic life, serving as a resource for human consumption, and contributing to the hydrological cycle. Surface water is vital for agriculture, recreation, and various industrial uses.

In contrast, the other options describe different types of water sources. Water stored underground refers to groundwater, which resides in aquifers and is accessed through wells. Water vapor in the atmosphere pertains to moisture present in the air, which can contribute to weather phenomena but does not represent liquid water available for direct use in surface ecosystems or human activities. Lastly, water in aquifers, while critical for providing drinking water and irrigation, is located beneath the Earth's surface and is categorized as groundwater rather than surface water. Therefore, the best definition of the term 'surface water' is indeed the water found in rivers, lakes, and streams.