https zoom us j 92000306539 pwd SHNmQ29aT2NnOVNjbm5JeFZYTTJPUT09 Meeting ID tophat Passcode 628356 Lecture 6 What s your favorite river Here s a story about mine San Francisco CNN Three weeks and about 400 miles ago I started a trip down the most endangered river in the United States California s San Joaquin The underloved river is born in the Sierra Nevada and snakes across one of the most productive agricultural regions in the world California s Central Valley I finished that journey which mostly involved kayaking but also a fair bit of walking since the San Joaquin runs dry for about 40 miles on Friday beneath the Golden Gate Bridge here in San Francisco It was a moment I ll always remember that behemoth cardinal red bridge towering overhead clanging in the wind the distant roar of traffic water rushing through a 1 7 mile channel that drains about 40 of this countrysized state s land area The ocean tossed the kayak around like a piece of doug 2 Videos 10 of Earth s people do not have enough water and nearly 40 must drink and bathe in water that does not meet even the most minimal standards of sanitation Freshwater is a limited resource and we are using it faster than it can be replenished Although methods are available to recover and purify some of the water we use conservation is also seriously needed On the planet covered with water why is its availability becoming a crisis Amount of water in the system is finite Less than 1 100 of this water is usable by humans Freshwater contains few dissolved ions Of this almost 35 million cubic kilometers are held in glaciers with additional water in rivers lakes and other organisms Hydrological Cycle linkage of all marine freshwater aquatic environments process of water travel from atmosphere earth atmosphere We depend on water going through state changes in the hydrological cycle Heat causes evaporation and transpiration Rising gases are cooled to yield another state change back to liquid The liquid water is returned to Earth to fill ground storage underground storage and to become available for uptake by plants through their root systems At each stage within the hydrological cycle bonds are made and broken Toxins may be picked up transported or eliminated Watershed The land area surrounding a body of water over which water such as rain could flow and potentially enter that body of water The World Health Organization estimates that 1 in 3 people more than 2 billion lack access to clean water Even more lack access to sufficient sanitation facilities 265 million gallons of raw sewage enters The Ganges River daily 3 000 people die from water borne illnesses in Africa daily Predictions suggest that 2 out of 3 people will face water shortages by 2025 In many developing nations people use nearby surface waters to meet their basic needs Without improved sanitation this water is contaminated with raw sewage and other forms of Contamination A Few Definitions Aquifer An underground region of soil or porous rock which is saturated with water Infiltration The process of water soaking into the ground Water Table The top of the underground water saturated region Water trickling down into the Earth naturally fills cracks and crevices while maintaining the water table and refilling the aquifer In coastal areas such as on the Georgia coast proximity to seawater and lower water tables have resulted in saltwater intrusion into the freshwater sources Where is much of Georgia getting their water ACT ACF River Basins in Georgia How to solve the water shortage in Georgia Damming rivers and creating reservoirs like Lake Lainer GA Benefits Source of freshwater Flood control Electricity production Boating fishing other recreation But there are also serious downsides An enormous potential for evaporation especially during summer when we need water the most globally more water lost than through industry and domestic The other serious downside is that others live downstream from us Tri State water wars River basins in dispute Metro Atlanta obtains 99 percent of its water water supply from rivers lakes and streams Groundwater cannot be a major source of supply because the bedrock is nonporous hard rock like Stone Mountain granite Rainfall is variable from as low as 30 inches per year to as high as 70 inches per year with an average of 50 inches per year There is no natural lakes in North Georgia Therefore metro Atlanta must use man made reservoirs to store water during rainy periods to use during dry times and drought Buford Dam creating Lake Lanier was constructed in 1957 Currently there are two federal reservoirs that are used for water supply in metro Atlanta Lake Lanier and Lake Allatoona Lake Lanier is located in the Apalachicola Chattahoochee Flint ACF River Basin Lake Allatoona is located in the Alabama Coosa Tallapoosa ACT River Basin Who are the players in the Tri State War Each state has its own concerns about the allocation of water Georgia The upstream user they are concerned that Georgia s increasing need for water will severely limit its own use of water for power generation fisheries among other uses Alabama A downstream user they are concerned that GA s increasing need for water will severely limit its own use of water for power generation fisheries among other uses Florida the other downstream user Florida wants enough freshwater to reach the Apalachicola Bay to support its multi million dollar shellfish industry To date fees in the two decades long tri state water wars negotiating and litigating kien tung to preserve Atlanta s access to drinking water from Lake Lanier the state Georgia have spent close to 20 million in outside legal Water scarcity will be an on on going issue in Georgia in part because of droughts July 2011 January 2012 June 2012 January 2017 August 2017 Solving global water shortages is not easy Much of our water usage can be reduced by using new water efficient technologies and waste water Buying less stuff and using less energy also saves water Three Gorges Dam China is economically strong Three Gorges Dam Video Benefit great economic Downside ability to change the length of day and night That we are not aware of it tho Turning Yangtze to a nightmare people have been forced homeless because the river height rise Phosphorus and Nitrogen are increasing in the water Three Gorges Dam is a massive hydroelectric dam that spans the Yangtze River in China It s the world s largest power station in terms of capacity 22 500 MW The