Report on Hydrological and Geochemical Processes in Large

0,11

MB

Scale River Basins

27

stron

4790

ID

World Commission on Dams

2000

rok

Contents

1. Introduction .1

2. Hydrology of Large Scale River Basins.2

2.1 Annual Floodplain Inundation 2

2.2 Climate Change and Hydrologic Variability. 3

2.3 Predicting Interannual Climate Cycles 4

2.4 Interdecadal Hydrologic Variability . 5

3. Erosion, Transport and Sedimentation in Large Scale River Basins.6

3.1 Variability in Sediment Supply. 6

3.2 Estimating Suspended Sediment Flux. 7

3.3 Sediment Exchange between Floodplains and River Channels 8

3.4 Climate Change and Sediment Supply 8

4. Geochemistry of Large Scale River Basins .10

4.1 Carbon Cycling in Large Rivers 10

4.2 Geochemical Exchanges between Rivers and Floodplains. 11

5. Ecohydrology of Large Scale River Basins .12

5.1 Dam-Related Case Studies 12

5.1.1 Manantali Dam, Senegal River, Senegal . 12

5.1.2 Al Wahda Dam, Sebou River, Morocco 12

5.1.3 Angosta del Bala Dam (proposed), Beni River, Bolivia 12

5.1.4 Sidi Salem Dam, Medjerdah River, Tunisia 13

5.1.5 Mequinenza-Ribarroja-Flix Dam Complex, Ebro River, Spain 13

5.1.6 Nestos River, Greece . 13

5.1.7 Itaipu and Yacyreta Dams, Parana River, Brazil, Paraguay and Argentina. 13

5.2 Greenhouse Gas Emissions from Reservoirs 14

6. Conclusions 16

6.1 Floodplain Vulnerability. 16

6.2 Quantifying Uncertainty 16

7. References 18