Module 2: Water Budget, Pressures and Impacts, Significant Water Management

Issues, Monitoring, Characterization Report

Basics on Water Balance

Senad Ploco

Content

• Hydrology and hydrological cycle;

• River basin water budget;

• World water budget;

• WISE reporting on water balance.

Introduction

• Where water comes from and where it goes?

• Why some of it is salty and some is fresh?

• Why sometimes there is not enough water and

sometimes too much?

Hydrology

• Hydrology = hydro + logos (water + science)• A water science that deals with the occurrence,

circulation and distribution of water of the earth and earth’s atmosphere.

• A good understanding of the hydrologic processes is important for the assessment of the water resources, their management and conservation on global and regional scales.

Hydrologic (Water) cycle

• Evaporation from water bodies

• Water vapor moves upwards

• Cloud formation• Condensation• Precipitation/Snow• Interception• Transpiration• Infiltration• Runoff–streamflow• Infiltration• Deep percolation• Ground water flow

Evaporation and transpiration

• ET = Eg + Ei + Ed + Ew + Es + Et• Eg - evaporation from snow and glacier surface • Ei - evaporation of rainfall quantity intercepted by vegetal covering and also by

constructions• Ed - evaporation of rainfall quantity accumulated in ground depressions without

possibilities of infiltration • Ew - evaporation from water surface • Es - evaporation from soil surface without vegetation• Et - transpiration produced by the vegetation biological process

Key river basin features

• Climate• Shape• Size • Slope• Soil type • Hydrogeology• Storage capacity

Orographical vs topografical watershed

River Basin Water Budget (km3)

Vin – Vout = ΔV (km3)

River Basin Water Balance (mm)

World Water Budget

• Total quantity: 1386.0 million km3

• Saline water (oceans): 1337.5 million km3

• Land water: 48.5 million km3

Land water• 13.8 M km3 is again saline• 34.7 M km3 is fresh water• 10.6 M km3 is both liquid and fresh• 24.1 M km3 is a frozen ice and

glaciers in the polar regions and mountain tops

Estimated World Water Quantitites

96%

1%

1%

2% Ocean-salineLand - salineFresh - LiquidFresh - Frozen

Annual World Water Balanace

Water balance of continents

Area (M km^2)

30.3

8.7 9.8

20.717.8

45

0

10

20

30

40

50

Africa Asia Australia Europe N.America S.America

Precipitation (mm/ yr)

686 736 734 670726

1648

0

500

1000

1500

2000

Africa Asia Australia Europe N.America S.America

Water balance of continentsPrecipitation (mm/ yr)

686 736 734 670726

1648

0

500

1000

1500

2000

Africa Asia Australia Europe N.America S.America

Evaporation (mm/ yr)

547 510415 383

1065

433

0

200

400

600

800

1000

1200

Africa Asia Australia Europe N.America S.America

Total Runoff (mm/ yr)

139226

319 287293

583

0

100

200

300

400

500

600

700

Africa Asia Australia Europe N.America S.America

Water balance of oceans

10712

75167

780

240

1010

1210

1040

120

1380

1140

0

200

400

600

800

1000

1200

1400

1600

Atlantic Arctic Indian Pacific

Area M km^2

Precp (mm/yr)

Evap. (mm/yr)

Water flow in Ocean

200 230

70 60

350

-300

130

-60

-400

-200

0

200

400

Atlantic Arctic Indian Pacific

Continental Inflow (mm/yr)

water exch. with ocean(mm/yr)

Trends in the World

April 2005, Laktasi, B&H

17

No RiverBasin

Countries A[km2]

q[l/s/km2]

1 Danube 18 801,463 8.2

2 Rhine DE, CH, FR, NL 160,000 12.5

3 Elbe PL, AU, CZ, DE 148,500 3.6

4 Scheldt F, B, NL 21,500 6.6

5 Thames UK 9,950 6.1

6 Sava SLO, CRO, BiH, SER, MON

97,200 6.0

Some EU rivers

WISE and Water Balance

Reporting by EU MS on:

• Water availability;

• Water abstraction;

• Water use.

WISE - Water availiabilty

Reporting per RBD on:

WISE and Water Abstraction

WISE and Water Use

Water availability?

Is there enough fresh water on the Earth?

• Current population number: 7.000.000.000

• Specific water consumption: 80 l/d/cap