Problem:

What is the hydrologic cycle? What are the pathways that precipitation falling onto the land surface of the Earth is dispersed to the hydrologic cycle?

Solution:

The hydrologic cycle is a continuous process in which water is evaporated from water surfaces and the oceans, moves inland as moist are masses, and produces precipitation if the correct vertical lifting conditions exist.

A portion of precipitation (rainfall) is retained in the soil near where it falls and returns to the atmosphere via evaporation (the conversion of water vapor from a water surface) and transpiration (the loss of water vapor through plant tissue and leaves). Combined loss is called evapotranspiration and is a maximum value if the water supply in the soil moisture conditions and soil may reenter channels layer as interflow or may percolate to recharge the shallow groundwater. The remaining portion of the precipitation becomes overland flow or direct runoff which flows generally in a downgradient direction to accumulate in local streams that then flow into rivers.