Hydrology

Hydrology is the study of water on Earth.

The water cycle describes the movement of water from bodies of water to the air back to land and back again. I've even written a water cycle story. Maybe I should dust it off and finish.

As a rule of thumb, the closer the land is to a large body of water, the more humid the climate is.

Sometimes the moisture laden air must go up in elevation. As the air moves up, it cools and has less energy to hold water and there is heavy rainfall. Then when the air descends in altitude, it warms up and holds what little water it had. Latitudes North and South of 30 degrees have Global Winds called the Prevailing Westerlies. On the West coast of the United States and Canada, there is a rain forest due to these two factors.

Why isn't there a rain forest along Mexico, Peru and Southern California. These areas are under the influence of the global winds called Tradewinds. Tradewinds are located between 30 degrees South and 30 degrees North and blow from the East to the West. They are called Easterlies.  Since they blow from the East to the West, they blow moisture away from the West coasts back to the Pacific Ocean. This causes the land to be dry. Rainfall from moisture is moisture that makes it from the Gulf of Mexico or Atlantic Ocean after traveling over a land mass.

My favorite item to teach was about groundwater. There used to be a lot of artesian wells where my dad grew up. An artesian well is a spring that breaks to the surface. The water spews because of the release of pressure. My dad used to take us to an artesian well they collected water when he was a boy. I remember the strong smell of sulfur. We would take a quick sip of the stinky, cold clear water. Then my dad would stand and drink, savoring the water of his youth.

Many of the artesian wells have disappeared because of development. My favorite story of my dad who was born in 1925 was his digging in the yard and an artesian well springs up. His older brothers said, "Oh no, you're going to flood the Earth. You better cover that up." My dad as a small boy put several feet of dirt to cover the spring.

The diagram below shows how groundwater moves through the Earth. The water table moves up and down depending on how much rainfall replenishes the water lost through surface water evaporation and removal by wells.