| 1. |
- Cederwall, klas
(författare)
-
Dams, flood protection, and risk
- 2012
-
Ingår i: Encyclopedia of Earth Sciences Series. - Dordrecht : Springer Netherlands. ; , s. 207-212
-
Bokkapitel (refereegranskat)
|
|
| 2. |
- Shah, T., et al.
(författare)
-
Workshop 7b (synthesis) : sustainable groundwater management in rural areas
- 2005
-
Ingår i: Water Science and Technology. - : IWA Publishing. - 0273-1223 .- 1996-9732. ; 51:8, s. 165-165
-
Tidskriftsartikel (refereegranskat)abstract
- Sustainable groundwater management strategies should be based on adequate assessment of the specific resource characteristics and human reliance on these resources. Disturbed groundwater balance reduces safe yield and degrades groundwater quality.
|
|
| 3. |
- Jonch-Clausen, T, et al.
(författare)
-
Workshop 1 (synthesis) : multipurpose stream management strategies
- 2004
-
Ingår i: Water Science and Technology. - : IWA Publishing. - 0273-1223 .- 1996-9732. ; 49:7, s. 87-88
-
Tidskriftsartikel (refereegranskat)abstract
- For a meaningful dialogue on balancing water uses between stakeholders in a river basin, adequate information and proper understanding, knowledge and access to reliable data are essential for all parties. Technological and economic components in water resources management have limited significance without the social context, and the legal framework plays a key role in the dialogue between stakeholders at all levels. Other aspects that fit into strategic planning and management of water resources projects are risk assessment, ecosystem requirements, credibility and trust building.
|
|
| 4. |
- Yang, James, et al.
(författare)
-
Large-amplitude oscillations in closed surge chamber
- 1992
-
Ingår i: Journal of Hydraulic Research. - 0022-1686 .- 1814-2079. ; 30:3
-
Tidskriftsartikel (refereegranskat)abstract
- The governing equations for surge oscillations in a closed surge chamber yield a second-order nonlinear differential equation for constant power. The surge stability is investigated by the direct method of Liapunov, which introduces the Liapunov function from the energy consideration. The nonlinear terms arising from large surges are included. The resulting stability criterion is demonstrated on a phase plane. For the equilibrium point of practical interest, the stability diagram specifies domains of asymptotic stability as a function of the safety factor of the surge-chamber. The diagram indicates that large-amplitude surges necessitate larger chamber size than that laid down by Svee for damping and the surge stability deteriorates with downward oscillations. By postulating sinusoidal surge motion, the critical chamber area is equal to the product of the critical area in case of small oscillations (Svee's formula) and a factor greater than 1.0. The factor is a function of surge amplitude and air cushion parameters for given turbine head. Stability criteria for open surge tanks can be obtained as special cases of those for closed ones.
|
|
| 5. |
- Larssonz, I., et al.
(författare)
-
Underground storage of water in natural and artificial openings in hard rocks in developing Countries
- 1981
-
Ingår i: Subsurface Space: Environmental Protection Low Cost Storage Energy Savings. - : Elsevier. - 9781483284217 ; , s. 459-466
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Rainfall variability is a major constraint to human life in arid and semi-arid areas. The variations can be seasonal as well as interannual. When the average precipitation is very low, fluctuations in rainfall, both as droughts and as floodings, can have severe consequences for a country. Many developing countries are situated in the arid and semi-arid belt on the Earth, e.g. in the Sahel belt of Africa.The rainfalls in these regions mostly appear as showers. Due to the dry soil most of the rain-water will go into surface run off and evaporate. Lakes and other natural basins for the collection of rainwater are very rare. To overcome this unequal distribution of rain it is necessary to find some kind of storage, natural or artificial, in which the rainwater, infiltrated into the ground, can be stored to be used during the dry season.The usual artificial type of storage is surface dams. However, they are very unfavourable in dry areas due to intensive evaporation and sedimentation. Underground storages in soil or rock do not have these disadvantages, On the other hand it is a problem to find necessary storage capacity in these media for the infiltrating water.Deep layers of alluvials have been used since long as aquifers. The storativity of these deposits is dependent on the extent of the strata and its porosity. Sedimentary rock, e.g. sandstones and limestones, have a natural porosity. They mostly are good aquifers.Hard rocks on the other hand have a secondary porosity, a fracture porosity, which can be waterbearing. Due to the tectonic type of the fractures, shear or tensile, they have quite different storage capacities. The authors show how special tensile fractures systems have a remarkable storativity. A tectonic model of this type of fracture is demonstrated.The rain water, which infiltrates the rock via the soil, is drained downstream the fracture system by gravity. A method is shown how to stop this drainage by means of an underground dam. This is achieved by an injection screen transvers to the main direction of the fractures. The authors show how the ground water storage in the subterranean dam and how the necessary leakage downstream are controlled by a simulation model.In areas, where drinking water is very costly, the storativity of the tensile fracture system can be increased considerably by the construction of an underground rock storage in close connection to the fractures. A preliminary model of this arrangement is discussed.
|
|
| 6. |
|
|
| 7. |
|
|
| 8. |
|
|
| 9. |
|
|
| 10. |
- Bergdahl, Lars, 1943, et al.
(författare)
-
Bevattningsteknik
- 1970
-
Rapport (övrigt vetenskapligt/konstnärligt)
|
|
