The subsurface area where all available spaces are filled with water is known as the saturated zone. This region, located beneath the unsaturated zone, forms the upper limit of groundwater. An example can be found after a significant rainfall event, where water percolates through the soil until it reaches a point where it encounters an impermeable layer, leading to the complete filling of pore spaces with water.
Understanding the fully water-filled subsurface region is crucial for water resource management, as it represents the primary source of groundwater used for drinking, irrigation, and industrial purposes. The size and quality of this region are influenced by factors such as precipitation, geology, and land use practices. Historically, its identification has been fundamental to locating and developing reliable water supplies.
