"GEOG 1100 Water ResourcesImportance of Water • Water supports all life on Earth • 71% of Earth’s surface is covered by water • 97% of water is in the Earth’s oceans • only 3% is freshwater • Quickly becoming one of the mostvaluable resources on Earth – Expected to overtake oil on a global market injust a few yearsUSGSThe Water Cycle • Water can change states (solid, liquid,gas) – Melting, freezing, evaporation, condensation,sublimation, deposition • Evapotranspiration = evaporation +transpirationThe Water Cycle – Annual Water Budget ChristophersonSoil Water Balance • Precipitation • Evapotranspiration – Potential evapotranspiration (maximum for givenenvironmental conditions) – Actual evapotranspiration • Deficit = potential evapotranspiration – actualevapotranspiration • Soil moisture storage can be positive (recharge)or negative (utilization) – Recharge = precipitation – potentialevapotranspiration, until soil is saturated – Utilization = actual evapotranspiration – precipitation • Surplus =precipitation – potentialevapotranspiration, in excess of rechargeChristophersonChristophersonChristophersonChristophersonSoil Water Balance • Most of the southwestern U.S. (except athigher elevations) seldom reaches asurplus • Exotic streams start in regions orelevations with a surplus, but flow toregions or elevations with a perpetualdeficit – Examples?Climate and Water Resources • Precipitation and temperature play an importantrole in determining soil water balance • Periods of lower than average precipitation(drought) lead to reduced actualevapotranspiration – Increased deficit • Periods of higher than average precipitation canlead to surplus – If runoff exceeds the capacity of streams, flooding canoccurClimate and the Great Salt Lake • We live in an endorheic basin – Runoff flows to an endorheic (terminal) lake,not to the ocean • As a result, the level of the Great SaltLake is determined by regionalprecipitation and evapotranspirationUtah Geological SurveyUniversity of UtahClimate and the Colorado River • The Colorado River system also stronglyresponds to climate because it is an exoticstream • The Colorado River Compact (1922)divided the water rights to Colorado Riverwater based on an average flow of 16.4million acre feet of water per year at LeesFerry, Arizona USGSMeko et al., 2007 (USGS)Christopherson(-118 feet) ChristophersonLake Mead Elevation http://www.arachnoid.com/, based on Bureau of Reclamation data1984 http://earthobservatory.nasa.gov/IOTD/view.php?id=372281989 http://earthobservatory.nasa.gov/IOTD/view.php?id=372281994 http://earthobservatory.nasa.gov/IOTD/view.php?id=372281999 http://earthobservatory.nasa.gov/IOTD/view.php?id=372282004 http://earthobservatory.nasa.gov/IOTD/view.php?id=372282009 http://earthobservatory.nasa.gov/IOTD/view.php?id=372281984 http://earthobservatory.nasa.gov/IOTD/view.php?id=372282009 http://earthobservatory.nasa.gov/IOTD/view.php?id=37228Utah Water Use • Utah uses 5.15 million acre feet of water peryear – Second highest per capita water use in the U.S. (260gallons per person per day)• 82% of water use is for agriculture, 18% is forresidential and industrial uses • 2.67 million acre feet are evaporated, transpired,or incorporated into products (consumptive use)• 65% of residential water use is outdoors, 35% ofresidential water use is indoorsUtah DWReSurface Displacement from groundwater changes InSAR Displacement Map Ground displacement map of a portion of the SaltLake Valley derived from a pair of satellite radarimages (9/19/96 - 1/2/97).4 40 ~3cm max. rebound 3 35 2 30 1 25 0 20 -1 15 GPS -2 10 GPS well inv (cm) -3 5 USGS well -4 0 0 100 200 300 400 500 1997 Day of year Rick Forster, U of U Geography 61 USGS wellwater level USGS well water level (40391611575901 C-2-2 9000-1) 60 59 58 57 Potential structural damage 56 1/4/1991 1/4/1992 1/3/1993 1/3/1994 1/3/1995 1/3/1996 1/2/1997 1/2/1998 1/2/1999 1/2/2000 1/1/2001 1/1/2002 Goundwater level (ft.below surface) GPS change in Hieght (cm) Change in well water level(cm)Utah DWRe from USGS dataWater Grabbing • Seizing control of or re-allocating waterresources from unregistered orunderrepresented local users – Taking the water rights away from local users – Does not have to be the direct water supply of theusers • May be water that is critical to ecosystems upon which thelocal users build their livelihoodsWater Grabbing • Water grabbing is not a new practice – Happened through much of the US Westduring the homesteading period • Typically conducted by agents with adisproportionate support fromgovernments – Wealthy landowners, multinationalcorporations, governments themselvesScale and Methods • Water grabbing has occurred at manyscales – Disputes between two farmers – Disputes between several countries • How it can be done: – Direct conflict – take by force – Legal loopholes – opportunistic circumventionof the spirit of laws, policies – Authority – acquiring, possessing, orinfluencing of bodies that control water – Lawmaking – influencing the water policiesHow? • Water grabbing requires someinvolvement of the governing body thatalready has authority over the water • The in-place government may be a partyto, a victim of, or a perpetrator of any or allof the methods • A changing climate is driving long-termplanning for businesses, governments – Those ahead of the curve, with resources,can exploit those who are trailing behindWhy? • Climate and cultural driven changes infood patterns globally – What people are eating, and where they aregetting it from • Shift away from oil into agrofuels – More agriculture for fuel = more water use • Increased use of water in industrialapplicationsWhy? • Market-based management of water – Water is a tradeable commodity already • Financially-driven conservation – Carbon-offsetting through creation ofprotected areas, including water, critical tofood production and economic stability • Globalized consumerism – Increased demand for: food, products, power,transportation • All require water to produce, transportImpacts • Increased use of an already limited supply • Loss of life and livelihoods – Agricultural yield decline – Limited or lost access to water for daily use • Includes drinking water – Potential for subsidence in ground wateraquifers • Seimic impacts, reduced storage of future water – Potential for land degradation • Some water uses cause environmental damage toecosystems, hydrologic systemsImpacts • Shifting of power between social groups – Conflict between neighbors, tribes, cities,countries, continents • Artificial markets – Water carries high intrinsic value, cancontribute to artificially inflated marketsystems • Cyclical impacts – As water is taken, degraded, other impactsincrease due to reduced supply"