Groundwater Explained — Aquifers, Water Table, Contamination & Karst Landscapes | Chapter 19 from Earth: Portrait of a Planet
Groundwater Explained — Aquifers, Water Table, Contamination & Karst Landscapes | Chapter 19 from Earth: Portrait of a Planet What lies beneath our feet, silently shaping landscapes and supplying our daily water? Chapter 19 of Earth: Portrait of a Planet by Stephen Marshak dives into the world of groundwater—the hidden reserve that sustains ecosystems, agriculture, and cities. For a podcast summary, watch the chapter video on YouTube , or read on for a complete breakdown. What is Groundwater and Where Does it Reside? Groundwater is the largest reservoir of liquid freshwater on Earth, filling the pore spaces and fractures in rock and sediment below the surface. It accumulates through infiltration —rain and snowmelt percolating downward until it reaches the water table , the boundary between unsaturated and saturated zones. Porosity, Permeability, Aquifers, and Aquitards Porosity: The percentage of a rock’s volume that is open space—higher porosity means more storag...