| 11. |
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| 12. |
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| 13. |
- Aronsson, Gunnar, et al.
(författare)
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Grand Canyon : a quantitative approach to the erosion and weathering of a stratified bedrock
- 1982
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Ingår i: Earth Surface Processes and Landforms. - : Wiley. - 0197-9337 .- 1096-9837. ; 7:6, s. 589-599
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Tidskriftsartikel (refereegranskat)abstract
- A new method is proposed for solving a differential equation arising from weathering-limited development of a valley. Allowance is made for horizontal stratification and overhang can be allowed to develop. The model is applied to the Grand Canyon and comments are included on its relevance
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| 14. |
- Ashby, M. F., et al.
(författare)
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A first report on diagrams for grain growth in welds
- 1982
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Ingår i: Acta Metallurgica. - : Elsevier BV. - 0001-6160. ; 30:11, s. 1969-1978
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Tidskriftsartikel (refereegranskat)abstract
- Data for carbide dissolution, grain growth and martensite formation in the heat-affected zone of a weld can be assembled into a diagram showing the extent of each, for different weld cycles, and at different points in the zone. The diagrams are based on elementary kinetic models for grain growth and carbide dissolution, integrated over the weld cycle; and on experimental data. The sets of poorly-known kinetic constants which appear in such a treatment are determined by fitting the equations to data from real or simulated welds, at certain fixed points. Diagrams are presented for six steels. As well as summarising much data they allow the effect of change in weld procedure, or of preheat, to be predicted.
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| 15. |
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| 16. |
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| 17. |
- Bengtsson, Lars
(författare)
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Groundwater and meltwater in the snowmelt induced runoff : [Eau souterraine et eau de fusion dans l'écoulement résultant de la fonte de la neige]
- 1982
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Ingår i: Hydrological Sciences Journal. - : Informa UK Limited. - 0262-6667 .- 2150-3435. ; 27:2, s. 147-158
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Tidskriftsartikel (refereegranskat)abstract
- The snowmelt runoff process from small basins is discussed. A differentiation is made between overland flow in the snowpack and groundwater flow induced by infiltrating meltwater. The effect of variations of the snowmelt intensity on streamflow is studied. It is shown that the runoff is high from the first day of snowmelt runoff if the streamflow is caused by overland flow, and that there are pronounced peaks every day, which almost correspond with the snowmelt intensity during daytime. Streamflow originating from groundwater, on the other hand, increases continuously during the snowmelt and shows only small daily peaks in the flow. Simultaneous overland and groundwater flow are also discussed. Observed runoff hydrographs from small basins are analysed in some detail. For the open fields studied the runoff shows the typical character of overland flow. For a rather large forested area the surface runoff also constitutes an important part of the runoff, but the groundwater baseflow is considerable.
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| 18. |
- Bengtsson, Lars
(författare)
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Inverkan av värmeuttag på temperatur- och cirkulationsförhållanden i istäckta sjöar
- 1982
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Ingår i: Vatten. - 0042-2886. ; 38:1, s. 3-16
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Three different circulation mechanisms are analyzed: 1) through-flow of a river; 2) wind generated oscillations; and 3) convective currents induced by heat flow from the bottom sediments. The through-flow takes place between the ice and a depth, which is mainly determined by the conditions at the inlet of the river into the lake. Just below this depth there is a sharp thermocline. The water mass below the thermocline is hardly affected at all by the through-flow. The bottom currents generated by the heat flow from the sediments is found to be of the order up to some tenth of metres per day. The stream velocity is shown to be proportional to the heat flow rate to the power 1/3. In discussing expected effects of withdrawal of heat from ice covered lakes with and without through-flow and heat with drawal with closed and open systems are disinguished. A thermocline is likely to develop also in lakes with no through-flow. The layer close to the ice with a temperature of almost 0 degree C must increase during the course of the winter.
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| 19. |
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| 20. |
- Bengtsson, Lars
(författare)
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Percolation of meltwater through a snowpack
- 1982
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Ingår i: Cold Regions Science and Technology. - 0165-232X .- 1872-7441. ; 6:1, s. 73-81
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Tidskriftsartikel (refereegranskat)abstract
- The hydraulics of meltwater percolation through a snowpack is analyzed in some detail. An implicit numerical model is used for determining the meltwater movement. The effect of freezing fronts of the free liquid water in the snowpack is evaluated. It is shown that even after a moderately cold night, it takes several hours of snowmelt before the snowpack again reaches its irreducible liquid content. The meltwater flux front moves very slowly down through the depth, where the liquid water has been refrozen during a preceding night. The time delay between the initiation of snowmelt at the surface and the start of run-off at the base of the snowpack is shown to be determined from a simple continuity reasoning. Finally, a comparison between theory and field measurements is made.
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