Chapter 7 Water: Hydrologic Cycle and Human Use. Introduction. The Aral Sea. Death of the Aral Sea. Located in present-day Kazakhstan and Uzbekistan. 1930’s it was decided that the area surrounding the sea could be used to grow cotton.
The Hydrologic Cycle:
Natural Cycle, Human Impacts
(amount of water vapor as a %
of what the air can hold at a
•Humidity increases as air warms
decreases as air cools
4 Physical Processes
3 Physical Loops
Evaporates and returns as precipitation
Surface runoff loop
Water runs across the ground surface and becomes part of the surface water system
Ground water loop
Water infiltrates, percolates down to join the ground water traveling through aquifers and then exiting through seeps, springs, or wells
• Microscopic liquid or solid particles originating from land and water surfaces that attract water vapor and promote the formation of droplets of moisture (AKA-condensation nuclei)
May originate naturally through volcanic eruption, wind-stirred dust and soil, and sea salts or may occur anthropogenically through sulfates, carbon, and dust.
• Water that infiltrates the ground has two alternatives.
to the atmosphere through one of the
Rising air over the equator is pushed from beneath by more rising air causing a “spill over” to the North and South. The two halves of the system (rising and falling air) make up the Hadley cell
Water: A Resource to Manage, a Threat to Control
Water is returned to its source
Electric power generation
Domestic use (public and self-supplied)
Saris used to filter cholera in Bangladesh.
Public Policy Challenges
Three Georges Dam