| GE |
|
PIX |  |
 |
 |
 |
 |
 |
| Geological photographs from around the world | ||||||||
Not all our water comes from under the ground. Some is derived from streams and rivers and stored in surface reservoirs. These artificial lakes are also used to store water for hydro-electric power stations and for flood control on seasonal rivers. Sites for dams and reservoirs should be carefully chosen, taking into account the rocks and geological structures. Failure to plan may lead to the failure of the dam.
Building a dam and reservoir involves not only geology but physics, meterology, hydrology, geography, politics and environmental issues as well.This Study Topic concentrates on the geological factors:
- dams are heavy and suddenly place a great burden on the underlying rocks;
- reservoirs are heavy and contain water which will leak out, given the opportunity.
|
The rock on which a dam is built should be strong and watertight. It is perhaps easier to list rocks which
are not strong and not impermeable, and to list the geological structures which would weaken the
foundation and allow water to escape!
The photograph shows the Hoover Dam, USA. |
 |
The rock which underlies the reservoir must be impermeable. Which rocks are suitable for this purpose?
On the other hand, which geological structures would allow water to escape?
|
In general terms, there are two types of dam construction - embankment or earth dams and concrete dams. The two
designs are quite different and require different construction materials, which affect the cost. For example, an
earth dam requires a huge amount of material which must therefore be available locally, to reduce transport costs.
The photograph shows the Aswan High Dam, Egypt, an embankment dam. |
 |
|
Dams and reservoirs are constructed for our benefit. But they also bring problems and dangers, ranging from the
loss of villages and farmland to the collapse of the dam.
The photograph shows the Three Gorges Dam, China, a concrete dam (while under construction). |
 |
Geopix Study Topic “Dams and Reservoirs”
- considers a variety of different geological settings, inviting an assessment of the suitability of each;
- considers the best rock types to use for the dam and reservoir;
- describes how unsuitable sites can be improved;
- describes the problems causaed by building dams and reservoirs;
- describes the construction and problems of a number of dams, including the Hoover Dam, Aswan High Dam and the Three Gorges Dam;
- illustrates the classic dam disaster of the Vaiont Dam;
and includes a Case Study: the Aswan High Dam
To order the "Applied Geology" Study Guide on CD, or the "Dams and Reservoirs" Study Topic by
download,
please visit the Geopix on-line store
The "Dams and Reservoirs" Study Topic includes the following pages:
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |