Journal #13 What are 4 factors that affect the depth of a water table? What is the recharge zone of an aquifer?

Wells and Springs Groundwater reaches Earth’s surface through wells and springs. A well is a hole that is dug to below the level of the water table and though which groundwater is brought to the surface. A spring is a natural flow of groundwater to Earth’s surface It is found in places where the ground surface dips below the water table

Ordinary Wells There are 2 types of wells and springs: Ordinary Artesian Ordinary wells work only if they penetrate highly permeable sediment or rock below the water table. If the rock is not permeable, groundwater cannot flow into the well quickly. (water can not be replaced quick enough)

Ordinary Wells Pumping water from the well lowers the water table around the well and forms a cone of depression. If too much water is taken from a well, the well will go dry.

Ordinary Springs Ordinary springs are usually found in rugged terrain where the ground surface drops below the water table. These springs may not flow continuously if there is variable rainfall and irregular depths. Springs may go dry during dry seasons or severe droughts.

Artesian Formation The ground water that supplies many wells comes from local precipitation. However, water in some wells come from hundreds of kilometers away. An artesian formation is a sloping layer of permeable rock sandwiched between 2 layers of impermeable rock. The permeable rock is the aquifer. Water enters at the recharge zone and flows downhill through the aquifer.

Artesian Wells and Springs As water flows downhill, it is under pressure. So when a well is drilled through the rock, water flows up through the well. An artesian well is a well through which water flows freely without being pumped. Artesian formations are also the source of water for some springs.

What are the differences between Artesian wells and Ordinary wells?

Hot Springs Groundwater is heated when the rock has been heated by magma. Hot groundwater that rises to the surface is called a hot spring. Mud pots form when weathered rock mixes with hot water to form a sticky, liquid clay that bubbles at the surface.