Global Water. Globally, 1.2 billion people live in areas with water supply.source:internationalwater

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1 Water Resources

2 Global Water Globally, 1.2 billion people live in areas with water supply.source:internationalwater inadequate

3 How sustainable are freshwater resources? 80 countries with 40% of world pop. Lack of water is constant threat Demand for water is doubling every 20 years In areas where there is enough water it is being mismanaged or polluted on a grand scale Lack of clean safe water kills 4500 children a day Out of 2.2 million deaths do to unsafe drinking water 90% were children under the age of 5

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7 Importance of Water Water keeps us alive Moderates climate Sculpts the land Removes and dilutes wastes and pollution Moves continually through the hydrologic cycle

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12 Where is the largest store of Earth s fresh water? 70% fresh water in ice caps and glaciers If all land glaciers melted the sea would rise 70 meters

13 Where is the rest of Earth s fresh water? 30% fresh water in groundwater Water is stored underground in aquifers it is able to move through the permeable rocks

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19 Find out the definitions of the following: Precipitation transpiration Infiltration Surface runoff Groundwater Percolation Evaporation condensation

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22 The Closed Global Hydrological System Not captured: 61% evaporates from the ground or transpires from plants-this is called green water What is available? 39% channels into blue water sources lakes, rivers, wetlands, and aquifers that people can tap directly before it evaporates or reaches an ocean.

23 The Closed Global Hydrological System The drainage basin system When precipitation reaches the surface it can flow a number of different pathways Small amount into rivers Vegetation absorbs some Once soil air pockets are full of water the soil is saturated and the water must flow on the surface of the soil- this is surface runoff.

24 The Closed Global Hydrological System The drainage basin system What happens if soil is not saturated? If soil not saturated rainwater soaks down into the soil Once it reaches impermeable rock (rock that does not allow water into it) the underground water level begins to fill up towards the surface. This water is still flowing down slope due to gravity. The upper level of underground water is known as the water table.

25 What could affect these flow rates? Deforestation

26 Agriculture

27 Urbanization

28 Research the 3 major impacts humans have on the hydrological cycle Urbanization Deforestation Agriculture Pen colors: Pink-red Purple-black Blue-blue Green-green As a group use the whiteboard and section it in three sections. Use your textbook page 202 and separate those into the 3 categories. Next go on my website and read about the 3 main impacts Finally do additional research to add to how humans have impacted the hydrological cycle. You are responsible for being able to discuss: How have humans impacted the hydrological cycle?

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30 Ocean Currents and Energy Distribution Using your notebook (2 pages) One page write out how Ocean currents work, and control the climate The other page color the ocean currents to accurately show how they circulate.

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32 The Closed Global Hydrological System Facts: 100,000 cubic kilometers of precipitation falls on Earth s land surface Very adequate for global population needs, HOWEVER much can t be captured and the rest is unevenly distributed. Uneven distribution: 60% of the world lives in areas that receive only 25 % of global annual precipitation Arid regions cover 40% of the world s land area but receive only 2% of global precipitation.

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36 By 2025 severe water stress will occur in Africa, Asia, and Middle East The Colorado river is running dry and groundwater is also being depleted faster than it can be replenished

37 Depleted Aquifers Provide ½ the world s drinking water Falling water tables brings severe consequences Ogallala aquifer has fallen 35 meters in 50 years

38 Depleted Aquifers In areas of Mediterranean the sea water has begun to seep into the aquifers Land subsidence is also a problem when aquifers become depleted Layers of soft underlying soil like clays and silts can not support the over pumping and since areas in the central valley recharge groundwater extremely slowly the water table collapses.

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40 Lab ideas

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