Practise IB ESS SL 2.1.22 by tracing how economic development and altered sediment flow can destabilise forests, wetlands and the ecosystem services they support.
| Years | Average sediment flow / tons yr^{-1} |
|---|---|
| 1921-1960 | 67.5 |
| 1971-1980 | 41.3 |
| 1981-1990 | 29.2 |
Table:Changes to sediment flow into the delta
Table: Changes to sediment flow into the delta: Sediment-flow and Danube-delta maintenance context
Table: Changes to sediment flow into the delta data
• 1921–1960 — average sediment flow: 67.5 tons yr⁻¹.
• 1971–1980 — average sediment flow: 41.3 tons yr⁻¹.
• 1981–1990 — average sediment flow: 29.2 tons yr⁻¹.
The Danube River delta is where the Danube flows into the Black Sea and includes UNESCO Biosphere Reserves and a World Natural Heritage site.
A delta is formed by continuous deposition of sediment carried by the river; sediment adds height and helps it extend into the sea.
The delta is a wetland ecosystem rich in plants, birds and fish, including over 1000 plant species, 300 bird species and endangered sturgeon.
Moldova takes nearly 20% of its water supply requirements from a branch of the Danube.
Suggest what effect this change in the sediment flow would have on the maintenance of the Danube River delta.
reduction in the height of the delta;
decreased expanse of the delta;
the delta cannot be maintained without continuous flow of sediment;
reduction in available minerals/productivity/habitats of the delta;