Part four Resources 地球上的资源 Water as a Resource The Global Water Budget Fluid Storage and Movement: Porosity and Permeability Subsurface waters Aquifer Geometry Confined and Unconfined Aquifers Other Factors in Water Availability Consequences of Groundwater Withdrawal Lowering the Water Table Compaction and Surface Subsidence Saltwater Intrusion Other Impacts of Urbanization on Groundwater Systems L。 ss of Recharge Artificial Recharge Other Features Involving Subsurface Water Sinkholes Karst Water Quality Measures of Water Quality Hard Water Water Use, Water Supply General U.S. Water Use Surface water versus Ground water Supply Regional Variations in Water Use Extending the Water Supply Conservation Interbasin Water Transfer DesalinationPart four Resources 地球上的资源 • Water as a Resource • The Global Water Budget • Fluid Storage and Movement: Porosity • and Permeability • Subsurface Waters • Aquifer Geometry • Confined and Unconfined Aquifers • Other Factors in Water Availability • Consequences of Groundwater Withdrawal • Lowering the Water Table • Compaction and Surface Subsidence • Saltwater Intrusion • Other Impacts of Urbanization • on Groundwater Systems • Loss of Recharge • Artificial Recharge • Other Features Involving Subsurface Water • Sinkholes • Karst • Water Quality • Measures of Water Quality • Hard Water • Water Use, Water Supply • General U.S. Water Use • Surface Water versus Ground Water • as Supply • Regional Variations in Water Use • Extending the Water Supply • Conservation • Interbasin Water Transfer • Desalination • Summary