Terrestrial Water Storage Change Due to

Human Activities

Dork SahagianEnvironmental Initiative

Lehigh University

Who Cares about Sea Level Rise?

Coastal Impacts

Fire Island along the South Shore of Long Island,New York, after the December 10-12, 1992northeaster

(From Leatherman, S. P. Social and economic costs of sea level rise. InSea Level Rise: History and Consequences, Douglas, B. C., M. S.Kearney, S. P. Leatherman, eds. Academic Press, 2001)

Sharp's Island, Maryland, ca. 1950. This photo shows what remained of an island that probably was approximately 700 acres in size at the time of original settlement in the late 17th century, and that still covered almost 600 acres in 1850. Until the first decades of the 20th century, Sharp's Island supported several large farms (at least one of 300 acres) and a hotel until 1910. Today, the island has disappeared, with only the historic Sharp's Island Light marking its former position.

NUMERICAL MODEL DEVELOPMENT

Sparse and Infrequent

Observations

Theoretical Misunderstandi

ng

Oversimplified

Formulation

Code Error

s

Unrealistic Assumptio

nsConfusion

Further Misunderstandi

ng

Further Refinement of Unimportant Details

Coincidental Agreement Between Theory and

Observation

Publication

Policy

Management

Directives

Causes of Sea Level Rise:

#1 uncertainty!

1. Glacial

2. Ocean Temperature

3. Direct Anthropogenic changes in land storage

• Account for past positive and negative anthropogenic contributions

• Determine which will continue into the future

• Normalize tide gauge and satellite records for above

• Then use to assess glacial and thermal contributions

• For future projections, include assessment of human activity

What to people do to cause sea level rise?

• Ground Water Mining

• Deforestation

• Desertification

• Wetland filling or drainage

• Surface Water Diversion

GROUND WATER MINING

Removal of fossil ground water from aquifers that do not appreciably recharge

Subsidence due to withdrawal from confined aquifer

SURFACE WATER DIVERSION

DESERTIFICATION

WETLAND DRAINING

TROPICAL DEFORESTATION

WATER STORED IN FORESTS

Tropical Biomass = 45kg/m2Dry/Fresh ratio = .25 3 parts water to 1 part biomass

135 kg/m2 vascular water= 13.5 cm water

Biomass conversionO2+C6H10O5 5H2O+6CO2

1kg biomass + 0.55kg waterso 45 kg/m2 biomass = 25 kg/m2 water

= 2.5 cm water2.5cm + 13.5cm = 16 cm water in plantsAnother 16 cm water in and around roots, soil moisture, leaves, etc.total 32 cm waterTropical deforestation rate= 15.4x10(6) ha/yr = 15.4x10(10)m2/yrSO- 0.32m x 15.4x10(10)m2/yr = 4.93x10(10)m3/yr

= 0.14mm/yr

ANTHROPOGENIC OCEANWARD WATER FLUX (SEA LEVEL RISE)

Activity PresentContribution(mm/yr)

Aquifer Mining .17

Surface WaterDiversion

.21

Desertification .01

Deforestation .14

Wetland loss .006

TOTAL 0.54

Dam Name Year Country Height Capacity

Owen Falls 1954 Uganda 31 204.80Bratsk 1964 USSR 125 169.00Aswan High 1970 Egypt 111 162.00Kariba 1959 Zambia 128 160.37Akosombo 1981 Ghana 20 147.96Daniel Johnson 1968 Canada 214 141.85Guri (RaulLeoni)

1986 Venezuela 162 135.00

Krasnoyarsk 1967 USSR 124 73.30Bennett,W.A.C 1967 Canada 183 70.31Zeya 1978 USSR 115 68.40Cabora Bassa 1974 Mozambique 171 63.00La Grande 2 1992 Canada 168 61.72La Grande 3 1981 Canada 93 60.02Ust-Ilim 1977 USSR 102 59.30Boguchany USSR 87 58.20Kuibyshev 1955 USSR 45 58.00Serra daMesa 1993 Brazil 150 54.40Caniapiscau 1980 Canada 56 53.79Bukhtarma 1960 USSR 90 49.80Ataturk 1992 Turkey 184 48.70Irkutsk 1956 USSR 44 46.00Tucurui 1984 Brazil 106 45.50Lower Kama 1987 USSR 45.00CerrosColorados

1972 Argentina 35 43.00

Vilyui 1967 USSR 64 35.90Sanmenxia 1960 China 106 35.40Kouilou 1992 Congo 137 35.00Hoover(Boulder)

1936 U.S. 221 34.85

Sobdradinho 1978 Brazil 43 34.10Glen Canyon 1966 U.S. 216 33.30Kemano 1952 Canada 32.70Churchill Falls 1971 Canada 16 32.32Skin Lake No.1

1953 Canada 25 32.20

Dam Name Year Country Height Capacity

Jenpeg 1975 Canada 30 31.79Volgograd 1958 USSR 47 31.50Sayano-Shushensk

9998 USSR 245 31.30

Keban 1974 Turkey 207 30.60Iroquois 1958 U.S. 20 29.96Itaipu 1982 Paraguay 190 29.00Missi FallsControl

1976 Canada 18 28.37

Kapchagay 1970 USSR 52 28.10Loma De La Lata 1977 Argentina 16 28.10Garrison 1956 U.S. 62 27.92Kossou 1972 Ivory Coast 58 27.68Oahe 1958 U.S. 75 27.43Zungoru 1994 Nigeria 27.10Raza Dyke 1970 Iraq 18 26.00Rybinsk 1941 USSR 30 25.40Longyangxia 9998 China 172 24.70Mica 1973 Canada 242 24.70Tsimlyansk 1952 USSR 41 24.00Kenney(Kemano)

1952 Canada 104 23.70

Ust-Khantaika 1970 USSR 65 23.50Shuikou China 101 23.40Furnas 1963 Brazil 127 22.95Fort Peck 1937 U.S. 76 22.12Xinanjiang 1960 China 21.60IlhaSolteira 1973 Brazil 74 21.17Yacyreta 1997 Paraguay 43 21.00Bureya 9998 USSR 139 20.90El Chocon 1973 Argentina 74 20.20Porto Primavera 1998 Brazil 38 20.00Tres Marias 1960 Brazil 75 19.79Toktogul 1978 USSR 215 19.50Kakhovskaya 1955 USSR 37 18.20WhitesandRapids

1942 Canada 12 17.87

Dam Name Year Country Height Capacity

Srinagarind 1981 Thailand 140 17.75Emborcacao 1981 Brazil 158 17.60Balbina 1987 Brazil 33 17.53Verkhne-Svirskaya

1952 USSR 32 17.50

Itumbiara 1980 Brazil 106 17.03Mingechaur 1953 USSR 80 16.00Boruca 1983 Costa Rica 15.00Kainji 1968 Nigeria 66 15.00Shuifeng 1943 China 106 14.70Manicouagan 1975 Canada 14.70Kolyma 9998 USSR 126 14.60Tabqua 1976 Syria 14.00Tres Irmaos 9998 Brazil 67 13.80FlanicieBanderita

1977 Argentina 34 13.80

Nizhne-Kamskaya

9998 USSR 36 13.80

Tarbela 1976 Pakistan 143 13.69Kenyir Dam 1984 Malaysia 150 13.60Kremenchug 1960 USSR 33 13.50Rogun 9998 USSR 335 13.30Alicura 1984 Argentina 13.20Saratov 1967 USSR 40 12.90Cheboksary 9998 USSR 42 12.80Sao Simao 1978 Brazil 120 12.74Loyang 1996 China 12.70Mosul 1983 Iraq 131 12.50Pine Portage 1950 Canada 43 12.36Des Roches 1955 Canada 62 12.33Kama 1954 USSR 37 12.20Bhumibol 1964 Thailand 154 12.20Grand Coulee 1942 U.S. 168 11.80Bersimis #1 1959 Canada 84 11.60NagarjunasagarDam

1974 India 125 11.55

Verkhne-Tulomskaya

1965 USSR 30 11.52

Global area covered by dammed reservoirs is 400,000 km2

75% of the world's dams and reservoirs have been built in the past 35 years, so the global rate of land loss from dam building is 0.75 x 400,000/ 35 = 8580 km2/ year

Why do we care about water impoundment?

1. Impoundment increases local water resource stocks.

2. Dams modify hydrographs- moderate flow variations.

3. Dams trap sediment- fill reservoir, starve coast.

4. Surface reservoirs evaporate- less total flow to coast.

5. Reservoirs support different biota than rivers.

6. Reservoirs add to oxygenation capacity - decompose

wastes.

7. New impoundment ameliorates sea level rise!

0

500

1000

1500

2000

2500

3000

3500

4000

1950 1960 1970 1980 1990 2000

History of Major Dam Construction

Year

(largest 100 dams)

•1 cm

WHAT IF WE STOP BUILDING NEW DAMS?

SEA LEVEL WILL RISE FASTER!

Effect of dams on ground water

Ground water filling = (KBt/n)1/2

Cumulative Reservoir Capacity [km3]

0

1000

2000

3000

4000

5000

6000

1 10 100 1000

FIGURE 1 - Dam Rank

Reservoir Capacity [km3]Res

ervo

ir C

apac

ity

(km

**3)

How to estimate volume impounded in small reservoirs?

1. Devise hydrologic land use classification scheme

2. Determine characteristic water impoundment

3. Measure areal extent of each class from remote sensing

Result- Total amount (rate) of impounded water

Why? We need to know the rate at which we have been impounding water and creating new water resources for:

1. Water resource analysis

2. Sea level projections

Water StorageTotal volume

removableSea level

equivalent20th Century

extraction rateSea level rise

rate(x10 3km3) (cm) (km3/yr) (mm/yr)

High Plains 4.0 1.1 12.0 0.03SW U.S. 3.0 0.83 10.0 0.03California 10.0 2.7 13.0 0.04Sahara 600.0 167.0 10.0 0.03Arabia 500.0 140.0 16.0 0.04Aral (lake) 1960 1.1 0.30 27.0 0.08 1990 0.3 0.08Aral (groundwater) 2.2 0.6 37.0 0.10Caspian (lake) 56.0 15.4 7.7 0.02Caspian (groundwater) 220.0 61.2 4.7 0.01Chad (lake) -0.04 -0.01 -2.5 -0.007Chad (groundwater) -0.08 -0.02 -3.5 -0.01Sahel (soil water) 0.1 0.03 3.4 0.01Wetland reduction 8.6 2.4 2.0 0.006Erosion -NA- -NA- 4.0 0.01Deforestation 3.3 0.9 49.0 0.14Dammed Reservoirs -8.6 -2.4 -172.0 -0.48TOTAL (w/o dams) 1408.2 392.4 189.8 0.53TOTAL (w/ dams) 1399.6 390.0 17.8 0.05

Anthropogenic Influences on Global Hydrology and Sea Level

BUT- Dams total does not include ground water or small dams!

0.5 mm/yr from large reservoirs

Add unknowns…

0.5 mm/yr from small, unregistered reservoirs

1 mm/y from impounded ground water

Sea level is rising!

What to do? - Store more water on land?

Two issues:

1. Continue building dams at 20th century rate? (known social/environmental consequences)

2. Purposefully sequester additional water(Unforeseen consequences!)

Sequester more water on land?

Some outrageous ideas:

• Divert surface water

• Pump water to high elevation dry basins

• Build strategic dams

• Enhance Antarctic precipitation

Basin Area Volume Sea Level Outflow Elevation

(1010m2) (1013m3) (cm) (m)Tarim 87 39 108 1500 (NE rim)Caspian 232 13 36 100 (Don River)East Iran 57* 7* 19* 900 (NW)*Afghan-ZabolBaluchistanChad 67 5.9 16 400 (Benue River)Uvs Nor 22 5.2 14 1600 (Samaltagatay ) QuidamQuidam 16 3.3 9 3500 (Lapiquan)Balkash-Zungar 30 1.9 5.3 400 (Caspian)Esfahan 5.1 5.8 1.6 1800 (NE to E. Iran)

interconnected basin.

Volume of empty Basins on Earth today

*This figure is for East Iran, Afghan- Zabol, and Baluchistan combined, for these are a complex

1000 kmCongo

Volume of “Congo Reservoir”

Basin area below 500 m elevation = 1.1x1012 m2

Volume = 1.0 x 1014 m3

Ocean basin area = 3.6x1014 m2

SO- Flooding Congo lowers sea level by 28 cm!

But don’t do it!

• “Natural” and anthropogenic changes in various reservoirs

• Uncertainties- small reservoirs, impounded ground water, aquifer mining rates, natural changes in ground water…

• Critical gaps- dams inventory, ground water, climate effects

• Recommendations- fill above gaps!

CONCLUSIONS

1. Water storage on land changes due to natural and human factors

2. Anthropogenic influences serve to both raise and lower sea level.(Most direct human activities raise sea level.)

2. Dams may completely counteract other human activities (and then some):• We have been “masking” the actual rate of 20th century sea level rise!• We must account for small impoundments.• We must account for ground water.

3. Several natural depressions could be filled with water:• How to get the water there? How to prevent it from leaving there?

4. There are some locations where large volumes can be stored behind dams.• Major new dams will cause major political and environmental disruption• Sea level amelioration would only be temporary

5. We need more complete inventories of land water storage reservoirs

Suggestions:(a humble opinion)

1. Address causes of sea level rise:ACTUAL mitigation (by new technologies, macroengineering or otherwise) of warming due to greenhouse gas emissions, land use

2. Better predict 21st century sea level rise (with, without mitigation)

3. Adapt strategically to predicted unavoidable sea level rise

4. Do not give the impression that actual climate change mitigation is unnecessary or impossible

BOTTOM LINE- Need a “diversified portfolio” of approaches to mitigation, sequestration and adaptation.

Thank you.

Example of Hydrological Land Use Classification Scheme

1. Moist temperate/boreal agricultural (>100cm/yr precipitation)

2. Moist tropical/subtropical agricultural (>100cm/yr)

3. Intermediate temperate agricultural (40-100 cm/yr)

4. Intermediate tropical/subtropical agricultural (40-100cm/yr)

5. Semi-arid agricultural (<40cm/yr)

6. Pasture/rangeland

7. Urban and other densely populated non-agricultural regions (>100cm/yr)

8. Urban and other densely populated non-agricultural regions (<100m/yr)

MODIS Reflectance Data

Climate data

Moisture anomaly fields

Thematic Irrigation MAP

LANDSAT, Local information, Field studies

Make hydrologic land use class map

Volume of water per area in each class

TOTAL IMPOUNDED WATER VOLUME

Project to 21st century for resource evaluation and sea level impacts

Average rate over 20th century

Rate of sea level influence

Vegetation Indices

Sub-pixel analysis

Map of water area per pixel

Cropland Distribution

Add Ground Water Contribution

Rate of increase of global water resources

Direct extrapolation branch

Unm

ixin

g b

ranch

Logical flowchart

1. Construct a global map of bio-hydro-climatological zones (direct branch)

2. Construct a map of irrigated/non-irrigated agriculture based on time series analysis of precipitation and moisture index, calibrated using field and Landsat data (direct branch)

3. Calculate small impoundment water volume per unit area using Landsat and field studies (direct branch)

4. Estimate small impoundment areas by unmixing MODIS, based on Landsat training data (unmixing branch)

5. Calculate total impounded water volume by multiplying the water volume per area in a zone by the total area of the zone (direct branch) and by transforming the unmixed area maps (unmixing branch) to volumes using field data

Land surface models provide insights, but more data are needed.

Spatial resolution insufficient to address specific anthropogenic influences

MODIS Reflectance Data

Climate data

Moisture anomaly fields

Thematic Irrigation MAP

LANDSAT, Local information, Field studies

Make hydrologic land use class map

Volume of water per area in each class

TOTAL IMPOUNDED WATER VOLUME

Project to 21st century for resource evaluation and sea level impacts

Average rate over 20th century

Rate of sea level influence

Vegetation Indices

Sub-pixel analysis

Map of water area per pixel

Cropland Distribution

Add Ground Water Contribution

Rate of increase of global water resources

Direct extrapolation branch

Unm

ixin

g b

ranch

Logical flowchart

1. Construct a global map of bio-hydro-climatologic zones (direct branch)

2. Construct a map of irrigated/non-irrigated agriculture based on time series analysis of precipitation and moisture index, calibrated using field and Landsat data (direct branch)

3. Calculate small impoundment water volume per unit area using Landsat and field studies (direct branch)

4. Estimate small impoundment areas by unmixing MODIS, based on Landsat training data (unmixing branch)

5. Calculate total impounded water volume by multiplying the water volume per area in a zone by the total area of the zone (direct branch) and by transforming the unmixed area maps (unmixing branch) to volumes using field data