GEOL 291 Lecture Notes - Lecture 16: Hydraulic Head, Aquifer, Dynamic Equilibrium

• School: College of Charleston
• Department: Geology and Environmental Geosciences
• Course: GEOL 291
• Professor: Ali

Document Summary

~160 wells to assess ground-water availability and drought conditions, ground-water management, interactions between ground and surface water, establish long-term data sites for climate change and modeling. Water use, climate and aquifer level trends. 500% increase in water withdrawals between 1960-2000 for agricultural irrigation, public supply, and industrial uses. Increased pumping pressure disrupts the equilibrium between saltwater freshwater interface. Dynamic equilibrium exists and moves in response to forces over differing time scales. Daily fluctuations in tide, seasonal variations and annual variations in aquifer recharge and discharge, long-term changes in sea level. Density difference between saltwater and freshwater causes a wedge of saltwater to extend landward and underlie less dense freshwater. In unconfined coastal aquifers this difference in density estimates 40 ftof freshwater below sea level for every 1 ftof freshwater above sea level (ghyben-herzberg approximation) Epa establishes contaminant levels for tds and chlorides in drinking water.