| 1. |
- Singh, V.P., et al.
(author)
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Kinematic wave modelling of saturated basal flow in a snowpack
- 1997
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In: Hydrological Processes. - 0885-6087 .- 1099-1085. ; 11:2, s. 177-187
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Journal article (peer-reviewed)abstract
- Movement of snowmelt water through a thin saturated layer at the infiltrating base of a snowpack is modelled by applying the kinematic wave theory. Analytical solutions are obtained for flow depth, velocity and discharge assuming that the rate of input to the saturated layer due to vertical percolation is constant. This assumption results in a linear rise and recession of the snowmelt hydrograph. The solutions are extended to the case of time-varying input. An explicit consideration of infiltration leads to a free boundary problem.
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| 2. |
- Singh, V.P., et al.
(author)
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Kinematic wave modelling of vertical movement of snowmelt water through a snowpack
- 1997
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In: Hydrological Processes. - 0885-6087 .- 1099-1085. ; 11:2, s. 149-167
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Journal article (peer-reviewed)abstract
- Vertical movement of snowmelt water through snowpacks is modelled by applying the kinematic wave theory. Analytical solutions are obtained for moisture flux, particle velocity, time history and velocity of meltwater front and total moisture content for a single melt event assuming that the melt rate is constant. These solutions are extended to the case involving more than one event.
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| 3. |
- Nyberg, Lars, et al.
(author)
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Water transit times and flow paths from two line injections of 3H and 36Cl in a microcatchment at Gårdsjön, Sweden
- 1999
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In: Hydrological Processes. - 0885-6087 .- 1099-1085. ; 13:11, s. 1557-1575
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Journal article (peer-reviewed)abstract
- To investigate groundwater transit times and flow paths in shallow till soil, within an acidification study at Gardsjon, Sweden, two line injections of Cl-36 and H-3 Were made in groundwater during 1992. The first injection in January, when the two tracers were injected at the same depth, gave tracer transit times from injection line to outlet of some hours due to a runoff event on the first day. The subsequent recession period left a considerable amount of tracer in the unsaturated zone, which had transit times that ranged from weeks to months. Tracer recovery at the outlet was 78% for H-3 and 47% for Cl-36. Cl retention was indicated. The second injection in November, when H-3 was injected at 30 cm depth and 36C1 at 60 cm depth, gave recoveries of 96% for H-3 and 83% for Cl-36. Apart from an advective flow-dependent tracer transport, very fast tracer pulses occurred. The velocities for those pulses were of the order of tens of metres per hour. Highest tracer concentrations were observed in the superficial soil layers, which suggest that these layers were the dominant flow paths.
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| 4. |
- Stahli, M, et al.
(author)
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Preferential water flow in a frozen soil - A two-domain model approach
- 1996
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In: Hydrological Processes. - 0885-6087 .- 1099-1085. ; 10:10, s. 1305-1316
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Journal article (peer-reviewed)abstract
- Earlier modelling studies have shown the difficulty of accurately simulating snowmelt infiltration into frozen soil using the hydraulic model approach. Comparison of model outputs and held measurements have inferred the occurrence of rapid flow even during periods when the soil is still partly frozen. A one-dimensional, physically based soil water and heat model (SOIL) has been complemented with a new two-domain approach option to simulate preferential flow through frozen layers. The ice is assumed to be first formed at the largest water filled pore upon freezing. Infiltrating water may be conducted rapidly through previously air-filled pores which are not occupied by ice; A minor fraction of water is slowly transferred within the liquid water domain, which is absorbed by the solid particles. A model validation with field measurements at a location in the middle-east of Sweden indicated that the two-domain approach was suitable for improving the prediction of drainage during snowmelting. In particular, the correlation between simulated and observed onset of drainage in spring was improved. The validation also showed that the effect of the high flow domain was highly sensitive to the degree of saturation in the topsoil during freezing, as well as to the hydraulic properties at the lower frost boundary regulating the upward water flow to the frozen soil and ice formation.
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| 5. |
- Semadeni Davies, Annette, et al.
(author)
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The water balance of a sub-Arctic town
- 1999
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In: Hydrological Processes. - 1099-1085. ; 13:12-13, s. 1871-1885
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Journal article (peer-reviewed)abstract
- Urban water balances differ from their rural counterparts due to extreme spatial heterogeneity, water imported from outside catchment boundaries and changed flow paths (e.g., drainage pipes and impervious surfaces). Urban catchments are characterized by increased peak discharges and fast response times, each contributing to specific environmental problems. The water balances of towns in the northern high latitudes are further complicated by snow which represents an energy dependent seasonal water store. This paper investigates the monthly water balance of Lulea (June 1992 to June 1996), a Swedish town of 71 000 inhabitants 100 km south of the Arctic Circle. The town has snow cover for five to six months of the year and thaw is usually in late April. Data available included daily precipitation, temperature and inflow to the Uddebo waste water treatment plant; and monthly potential evapotranspiration, groundwater levels and water supply statistics. Of interest were the seasonal differences in runoff volumes and flow pathways to the waste water treatment plant and receiving waters. It was found that increased volumes of runoff, reduced concentration times and long duration led to flooding and high waste water loads at the treatment plant. The surface water component of sewage originates from direct flow into pipe inlets and infiltration into sewer pipes. Autumn and spring were found to be the periods of groundwater recharge, although frozen soil can limit water percolation. Copyright (C) 1999 John Wiley & Sons, Ltd.
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| 6. |
- Bobba, A. G., et al.
(author)
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Application of a watershed runoff model to north-east pond river, Newfoundland: To study water balance and hydrological characteristics owing to atmospheric change
- 1997
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In: Hydrological Processes. - 1099-1085. ; 11:12, s. 1573-1593
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Journal article (peer-reviewed)abstract
- The hydrological sensitivities to long-term climate change of a watershed in Eastern Canada were analysed using a deterministic watershed runoff model developed to simulate watershed acidification. This model was modified to study atmospheric change effects in the watershed. Water balance modelling techniques, modified for assessing climate effects, were developed and tested for a watershed using atmospheric change scenarios from both state of the art general circulation models and a series of hypothetical scenarios. The model computed daily surface, inter- and groundwater hows from the watershed. The moisture, infiltration and recharge rate are also computed in the soil reservoirs. The thirty years of simulated data can be used to evaluate the effects of climatic change on soil moisture, recharge rate and surface and subsurface flow systems. The interaction between surface and subsurface water is discussed in relation to climate change. These hydrological results raise the possibility of major environmental and socioeconomic difficulties and have significant implications for future water resource planning and management. (C) 1997 John Wiley & Sons, Ltd.
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| 7. |
- Molder, M, et al.
(author)
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Regional sensible heat flux and thermal roughness length of an inhomogeneous landscape
- 1998
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In: HYDROLOGICAL PROCESSES. - : JOHN WILEY & SONS LTD. - 0885-6087. ; 12:13-14, s. 2115-2131
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Journal article (other academic/artistic)abstract
- Knowledge of regional roughness parameters is needed for remote sensing and large-scale modelling purposes. The presently available estimates of the most problematic parameter, namely the regional thermal roughness length (z(0t)), have mostly been determi
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| 8. |
- Nyberg, L
(author)
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Spatial variability of soil water content in the covered catchment at Gardsjon, Sweden
- 1996
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In: HYDROLOGICAL PROCESSES. - : JOHN WILEY & SONS LTD. - 0885-6087. ; 10:1, s. 89-103
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Journal article (other academic/artistic)abstract
- The spatial variability of soil water content was investigated for a 6300 m(2) covered catchment on the Swedish west coast. The catchment podzol soil is developed in a sandy-silty till with a mean depth of 43 cm and the dominant vegetation is Norway spruc
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| 9. |
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| 10. |
- Seibert, J, et al.
(author)
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A test of TOPMODEL's ability to predict spatially distributed groundwater levels
- 1997
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In: HYDROLOGICAL PROCESSES. - : JOHN WILEY & SONS LTD. - 0885-6087. ; 11:9, s. 1131-1144
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Journal article (other academic/artistic)abstract
- TOPMODEL was calibrated to a small catchment using precipitation and runoff data. Acceptable fits of simulated and observed runoff were obtained during both the calibration and validation periods. Predictions of groundwater levels using this calibration d
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