Notes VII

Mendoza, Argentina  ©eop

In our first session we talked about siltation and the failure of dams. Over the past week, a small dam in the Kingstowne section of Fairfax County failed draining small lake and leading to the death of wildlife. Fortunately no human lives or even housing units were damaged by the dam failure, but it left a mess that will require a substantial sum of money to repair. That break was not unexpected, for the dam was in need of rebuilding, and the lake behind it had been fouled by silt. Left behind is a swamp, probably a stinking swamp should warmer weather return in the next week or two. Dams, like all human devices for water control, need constant maintenance if they are to continue in service. Failure to maintain can lead to catastrophic collapse, and a dam failure can lead to loss of property and even loss of human life.

The last half of the session today, 6 October, and a substantial part of the next session on 13 October depend on a Power Point presentation developed by Prof. Arjen Hoekstra at the University of Twente in the Netherlands. To review the materials used today and to preview those to be discussed in the next session, the Power Point or a PDF version of it can be downloaded from the page: http://www.waterfootprint.org/?page=files/Presentations 

Second Class Session 29 September 2010

World Water Supplies: The Coming Crisis

Mendoza, Argentina ©eop

Session II: The Physical Geography of Water Supplies: Some Illustrative Materials

Thanks to a computer glitch, three videos I had wanted to use with the session were unavailable.  Below are those videos and a couple of notices. I shall post the outline of the session in a day or two.

I. World rainfall by Month, 1998-2009

Source: NASA Earth Observatory

II. World Snow Cover

Source: NASA Earth Observatory

3. Great Artesian Basin of Australia

Source: Government of Australia

The following information is thanks to one of our class members:
"Liquid Assets - The Big Business of Water   'The host explores the coing water crisis as fresh water becomes harder to find"  CNBC Thursday 30 October 9-10 pm
According to other class embers CNBC is available at Channel 68 on Cox cable and 102 on Verizon. The CNBC website does not give much additional information, but it sounds as if the broadcast will be worth watching.

Once again, by next session 6 October, please work out your water footprint. Go to the website at http://www.waterfootprint.org/?page=cal/WaterFootprintCalculator

First Class Session 22 September 2010

Mendoza Argentina ©eop

I am using some copyrighted items in the power pointe presentations, and I cannot legally post them without permissions (the fair use doctrine allows their use in class sessions), so instead I shall post outlines of the sessions along with notes where appropriate.

World Water Supplies: The Coming Crisis

Session I:  Introduction - Water in Human Culture

I. Introduction.

A. "Many of the wars of the 20th century were about oil, but the wars of the 21st century will be over water." Serageldin, V.P. World Bank.

B. Huron California and conflict over water in California (see Wikipedia entry on Huron).

II. Course Schedule:

22 September Introduction – Water and Human Civilization

29 September The Physical Geography of Fresh Water Supplies

6 October Human Uses of Fresh Water

13 October The Social Organization of Water Distribution

20 October Water Supply Challenges in Arid Zones

27 October Water Supply Challenges in Humid Zones

3 November Issues for the (Near) Future: Demand Growth, Climate Change, Contamination and the Control of Water Supplies

10 November Fresh Water Supplies – The Coming Crisis

III. Water "Wonderful Stuff."

A. Some characteristics of water.

1. Abundant in universe and on earth.

2. All 3 phases (liquid, solid, gas) found on or near earth's surface.

3. Ice floats!

4. Good reaction and transport medium.

5. "Universal solvent."

B. Water and life.

1. All known forms require water at some stage.

2. Many (most?) forms incorporate water as part of body.

3. Human life and many life forms essential to human survival require fresh water.

C. Fresh water.

1. 2.5 percent of earth's water (graphic)

1. Much in glacial ice (Antarctica, Greenland, sea ice)

2. Much otherwise inaccessible!

2. Characteristics.

Fresh Water	Brackish Water	Saline Water	Brine
<0.5 ppm	0.5-30 ppm	30-50 ppm	>50 ppm

IV. Hydraulics and human civilization.

A. Water Management.

1. The 3 "Ss" of water management.

a. Salt.

b. Silt.

c. (Social) Stability.

2. Water management issues.

a. Flooding and drainage.

b. Seasonal variation.

c. Regional variation.

d. Multi-year variation.

c. Cadaster.

C. Early civilizations and water management (hydraulic civilizations?)

1. Mesopotamia ("Fertile Cescent")

1. Seasonal variation.

2. Regional distribution of water.

2. Indus Valley.

1. Seasonal variation.

2. Regional distribution.

3. Mesoamerican civilizations.

1. Access to water (Mayan in Yucutan to Peten)

2. Control of drainage (Andean)

4. China, the Yangtze and "Tian Ming" the Mandate of Heaven.

D. Water and the fall of civilizations.

1. Salting of water supplies and soil.

2. Silting of water supply conduits.

3. Social upheaval (war, revolution)

4. Environmental change (climatic change).

(sorry for the formatting; I am mixing materials originally composed using Open Office, Microsoft Office, and Google. To no one's surprise, they do not interchange well!)

I forgot to show it in class, but after I had put together the materials for the first session I came across a new book which covers much the same ground and in very much greater detail. I strongly recommend:

Solomon, Steven. 2010, Water: The Epic Struggle for Wealth, Power, and Civilization. New York: Harper. 596 pp. ISBN 978-0-06-054830-8.

Do not forget to calculate your water footprint for our session on 6 October. Go to the website'\:

•http://www.waterfootprint.org/?page=cal/WaterFootprintCalculator

The Occoquan Watershed

George Mason University Campus Fountain, July 2010

©EOP

This morning I was looking for some local materials to include in the water course, and I chanced upon a good (if too small a scale) land-use map for the Occoquan Watershed (I hope to find a similar map at a bigger scale for use in a Power Point). Our Fairfax City house sits just slightly to the Potomac watershed (small streams draining directly into the river) side of the interfluve dividing the watersheds of the Potomac and the Occoquan. The GMU campus sits on the interfluve,and a part of the campus is on the opposite slope with water draining into small streams feeding the Occoquan (which itself eventually, just southeast of its eponymous town, flows into the Potomac).

Bull Run, one of the Occoquan's tributaries is very famous, for its small valley at the edge of Manassas City was the site of two of the more vicious battles of the Civil War. At the time of the Civil War and until quite recently the almost 1550 square kilometer basin of the Occoquan was predominantly rural with farmlands, wooded areas and only a few small towns and the small city of Manassas. Since the 1970s and especially since 1990 the watershed has  been rapidly urbanized with farm fields and pastures converted to townhouse projects and small "estates" along with the usual fast food and strip mall development. That has radically changed the timing and the quality of water run off into the Occoquan, for now much of the watershed is paved and impermeable even as urban uses add contaminants to the water flowing toward the river..

Prior to much urbanization the river became an important drinking water source supplying much of the urban water in Prince William County (including Manassas and Manassas Park cities) and some of the water consumed in Fairfax County, the two largest counties by population in Virginia. Altogether nearly 1,200,000 people are connected to water supply systems which use some Occoquan river water. A substantial dam impounds a tributary of the river and creates Lake Manassas, a water supply reservoir for its namesake city. Downstream another dam impounds the Occoquan Reservoir supplying much of Prince William County and large parts of adjacent Fairfax County. While other sources of water are used by both counties, the Occoquan could in an emergency supply most users. A bit further downstream yet near the town of Occoquan is one of the largest sewage treatment facilities in the Washington, DC metropolitan area, sending treated water into the Occoquan just before that river joins the Potomac.

A crucial element in the urban water supply of Washington, DC's Virginia slurbs, the Occoquan is also a major recreation resource for the area, and the undeveloped lands along its banks provide a substantial amount of open space. Unfortunately the stream is badly polluted in places, and runoff from developed areas makes it an endangered stream. The Prince William Conservation Alliance has an excellent webpage examining the issues of pollution in the Occoquan basin. The quality of water in the river is important for those of us condemned to live in Northern Virginia!

Watershed Map from Prince William Conservation Alliance.

Water and Food I: Coffee (not really food, of course)

La Bolsa de Café, Buenos Aires, Argentina 2008

©EOP

The interconnectedness of water supply, food supply and the human population was the basic idea prompting this set of courses, and I hope at least a few OLLI members will enroll in all three even if each course is designed to stand independently. The topics of three courses are interdependent in many ways, but we are often inclined to ignore those connections. Over the past few days I have been doing some research on the connections between water supply and food production, and I have discovered a true cornucopia of material (pun intended). 

We need water directly for hygiene and sanitation, but by far the largest human use of water is for agriculture and the production and processing of food. Each food unit we consume is composed of various inputs of which water is a crucial one. Even the crops most tolerant of aridity demand at least a little water to grow and produce food. Many foodstuffs are ravenous consumers of water requiring hundreds or even thousands of liters of water for each kilogram or liter of product. That is a subject we shall look at in some detail in the course and perhaps in future blog postings. Today I would like to introduce the water demands just one thing many people consume regularly, coffee.

Coffee is not really food, and with a little pain - a couple of days of caffeine deprivation headaches - most of us could probably stop drinking it (though I really like the taste of good coffee). Coffee is an obvious user of water, for each cup brewed requires us to draw water from the tap. That single cup of coffee requires not just the cup (125 ml) we put in the coffee maker but a total of 140 liters of water! Not so obvious when we brew the pot is the large amount of water needed to grow, process, and transport the beans to us as well as the water needed to produce  the electricity, dispose of the waste, etc. The Dutch, who are known for their fine coffee and their coffee drinking tradition, have studied the issue and in a paper titled "The water needed to have the Dutch drink coffee" two Dutch scholars have outlined the demand for water related to coffee drinking in the Netherlands, the water footprint of Dutch coffee. It makes for fascinating and thought provoking reading!


By comparison to most meat products, our liquid refreshments, including coffee, tea (30 liters per cup) , and beer (75 liters per 250 ml glass) demand fairly modest quantities of water. The Water Footprint Network, operated from the University of Twente in the Netherlands in cooperation with UNESCO,offers a great set of webpages and downloadable publications on the water demands of lots of different foods and other products and the issue of water footprints.

Introduction

Beginning in the Autumn 2010 term, I am leading three related courses at the Tallwood facility of OLLI at George Mason University: Autumn 2010 World Water Supplies -  the Coming Crisis; Spring 2011 World Food Supply - Famine on the Horizon?; and Spring 2012 World Population Dynamics and Growth (that last title may change as the proposed course is rather far into the future). This blog is intended to support those courses with comments on matters related to the courses, responses to questions and comments raised in class sessions, recommended readings, links to useful supplementary materials, and anything else that seems worth pursuing in the informal context of a blog.