Impacts cumulatifs du développement hydro-électrique sur le bilan d'eau douce de la baie d'Hudson

1994 ◽  
Vol 21 (2) ◽  
pp. 297-306 ◽  
Author(s):  
François Anctil ◽  
Richard Couture
Keyword(s):  
Water Balance ◽  
Fresh Water ◽  
Marine Environment ◽  
Mass Exchange ◽  
Spatial Scales ◽  
Ice Cover ◽  
Hudson Bay ◽  
Freezing And Thawing ◽  
Runoff Water ◽  
Hydroelectric Development

This paper discusses the consequences on the marine environment, more specifically on the fresh water balance, of the hydroelectric development of several tributaries of Hudson Bay, including James Bay and Foxe Basin. The fresh water balance is determined by identifying, at different scales, the modifications caused by each complex. The main inputs are the freezing and thawing of the ice cover, runoff water, and mass exchange at the air–water interface. Three spatial scales were used to obtain the resolution required to document the cumulative effects of fresh water balance modifications on the water surface layer: the Hudson Bay, the Hudson Strait, and the Labrador Sea. Finally, the addition of the proposed Grande-Baleine hydroelectric complex is examined from the available information and forecasts. Key words: hydroelectric development, impact, marine environment, fresh water balance, ice cover, runoff water, mass exchange.[Journal translation]

Fresh water balance of the Gulf Stream system in a regional model study

2001 ◽  
Vol 18 (1-2) ◽  
pp. 17-27 ◽  
Author(s):  
R. Gerdes ◽  
A. Biastoch ◽  
R. Redler
Keyword(s):  
Water Balance ◽  
Fresh Water ◽  
Gulf Stream ◽  
Regional Model ◽  
Model Study ◽  
Stream System

scholarly journals The hydrological significance of mountains: from regional to global scale

2004 ◽  
Vol 8 (6) ◽  
pp. 1017-1030 ◽  
Author(s):  
D. Viviroli ◽  
R. Weingartner
Keyword(s):  
Fresh Water ◽  
Significant Proportion ◽  
Arid Zones ◽  
River Rhine ◽  
European Alps ◽  
Rhine River ◽  
Runoff Water ◽  
Mountain Areas ◽  
Discharge Data ◽  
Total Discharge

Abstract. Mountain regions supply a large share of the world’s population with fresh water. Quantification of the hydrological significance of mountains, however, is subject to great uncertainty. Instead of focusing on global averages in advance, the present analysis follows a catchment-based approach using discharge data provided by the Global Runoff Data Centre (GRDC). The River Rhine originating in the European Alps is chosen as a first study area, revealing the hydrological relationship between mountainous and lowland regions in a well-documented area. Following the findings from this analysis, different aspects of runoff characteristics for a total of 22 case-study river basins world-wide have been investigated and compared, for a global view. The view has been extended through aspects of climate and human use of mountain runoff. The particular hydrological characteristics of mountain areas are characterised by disproportionately large discharges. In humid areas, mountains supply up to 20–50% of total discharge while in arid areas, mountains contribute from 50–90% of total discharge, with extremes of over 95%. The overall assessment of the hydrological significance of mountain areas reveals that the world’s major "water towers" are found in arid or semi-arid zones where they provide essential fresh water for a significant proportion of a quickly growing global population. Keywords: mountain hydrology, global comparative assessment, runoff, water resources, sustainability, Rhine River, European Alps

Salt and Water Balance in Salmon Smolts

1970 ◽  
Vol 52 (3) ◽  
pp. 553-564
Author(s):  
W. T. W. POTTS ◽  
MARGARET A. FOSTER ◽  
J. W. STATHER
Keyword(s):  
Water Balance ◽  
Fresh Water ◽  
Sodium Pump ◽  
Sea Water ◽  
High Rate ◽  
Exchange Diffusion ◽  
Rapid Changes ◽  
Alternative Hypotheses ◽  
Salt And Water Balance

1. Salmon smolts adapted to sea water maintain a high rate of turnover of both sodium and chloride, but when adapted to fresh water the rate of turnover is low. 2. Only a small part of the influx takes place through the gut. 3. On immediate transfer from sea water to dilute sea water or to fresh water the influxes decline rapidly, but on transfer from fresh water to sea water the restoration of the fluxes takes place slowly. 4. The alternative hypotheses that the rapid changes are due to exchange diffusion or to rapid adjustments of the sodium pump are discussed.

10. International Watercourses: Environmental Protection and Sustainable Use

2021 ◽  
pp. 571-616
Author(s):  
Alan Boyle ◽  
Catherine Redgwell
Keyword(s):  
Environmental Protection ◽  
Fresh Water ◽  
Marine Environment ◽  
Natural Resource ◽  
Sustainable Use ◽  
Environmental Problems ◽  
Finite Resource ◽  
International Water Law ◽  
International Water ◽  
The Law

This chapter turns to issues related to fresh water. Fresh water is a finite resource and the more we pollute it, the more issues we have with its use. A sustainable supply of fresh water is vital to life. Historically, international water law was not particularly concerned with environmental problems. This chapter talks of ‘international watercourse’ which is a convenient designation for rivers, lakes, or groundwater sources shared by two mor more states. The law of international watercourses has for most of its history been concerned with the allocation and use of a natural resource of international significance, not with its conservation or environmental protection. While it can be asserted with some confidence that states are no longer free to pollute or otherwise destroy the ecology of a shared watercourse to the detriment of their neighbours or of the marine environment, definitive conclusions concerning the law in this area are more difficult to draw.

scholarly journals On the Response of a Sea-Ice Cover to Changes in Surface Temperature

1966 ◽  
Vol 6 (45) ◽  
pp. 439-442 ◽  
Author(s):  
Peter Schwerdtfeger
Keyword(s):  
Growth Rate ◽  
Sea Ice ◽  
Surface Temperature ◽  
Ice Cover ◽  
Hudson Bay ◽  
Time Separation ◽  
The Mean ◽  
Temperature And Growth

The time separation between related extremes in the values of surface temperature and growth rate of a floating ice cover are shown to depend on the mean ice temperature and thickness. A quantity termed the lag coefficient is introduced for which observations from Churchill, Hudson Bay, and Davis, Antarctica, suggest a dependence on temperature but not on geography.

scholarly journals A new approach to estimating Mean Flow in the UK

2002 ◽  
Vol 6 (4) ◽  
pp. 709-720 ◽  
Author(s):  
M. G. R. Holmes ◽  
A. R. Young ◽  
A. Gustard ◽  
R. Grew
Keyword(s):  
Soil Moisture ◽  
Water Balance ◽  
Accurate Estimation ◽  
Mean Flow ◽  
Time Step ◽  
Runoff Water ◽  
Data Set ◽  
Water Balance Models ◽  
The Uk ◽  
Drying Curve

Abstract. Traditionally, the estimation of Mean Flow (MF) in ungauged catchments has been approached using conceptual water balance models or empirical formulae relating climatic inputs to stream flow. In the UK, these types of models have difficulty in predicting MF in low rainfall areas because the conceptualisation of soil moisture behaviour and its relationship with evaporation rates used is rather simplistic. However, it is in these dry regions where the accurate estimation of flows is most critical to effective management of a scarce resource. A novel approach to estimating MF, specifically designed to improve estimation of runoff in dry catchments, has been developed using a regionalisation of the Penman drying curve theory. The dynamic water balance style Daily Soil Moisture Accounting (DSMA) model operates at a daily time step, using inputs of precipitation and potential evaporation and simulates the development of soil moisture deficits explicitly. The model has been calibrated using measured MFs from a large data set of catchments in the United Kingdom. The performance of the DSMA model is superior to existing established steady state and dynamic water-balance models over the entire data set considered and the largest improvement is observed in very low rainfall catchments. It is concluded that the performance of all models in high rainfall areas is likely to be limited by the spatial representation of rainfall. Keywords: hydrological models, regionalisation, water resources, mean flow, runoff, water balance, Penman drying curve, soil moisture model

scholarly journals Water Regulation in Cyanobacterial Biocrusts from Drylands: Negative Impacts of Anthropogenic Disturbance

Water ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 720 ◽  
Author(s):  
Yolanda Cantón ◽  
Sonia Chamizo ◽  
Emilio Rodriguez-Caballero ◽  
Roberto Lázaro ◽  
Beatriz Roncero-Ramos ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Water Balance ◽  
Soil Water ◽  
Water Loss ◽  
Spatial Scales ◽  
Arid Ecosystems ◽  
Rainfall Simulation ◽  
Water Regulation ◽  
Natural Rainfall ◽  
Bare Soils

Arid and semi-arid ecosystems are characterized by patchy vegetation and variable resource availability. The interplant spaces of these ecosystems are very often covered by cyanobacteria-dominated biocrusts, which are the primary colonizers of terrestrial ecosystems and key in facilitating the succession of other biocrust organisms and plants. Cyanobacterial biocrusts regulate the horizontal and vertical fluxes of water, carbon and nutrients into and from the soil and play crucial hydrological, geomorphological and ecological roles in these ecosystems. In this paper, we analyze the influence of cyanobacterial biocrusts on water balance components (infiltration-runoff, evaporation, soil moisture and non-rainfall water inputs (NRWIs)) in representative semiarid ecosystems in southeastern Spain. The influence of cyanobacterial biocrusts, in two stages of their development, on runoff-infiltration was studied by rainfall simulation and in field plots under natural rainfall at different spatial scales. Results showed that cover, exopolysaccharide content, roughness, organic carbon, total nitrogen, available water holding capacity, aggregate stability, and other properties increased with the development of the cyanobacterial biocrust. Due to the effects on these soil properties, runoff generation was lower in well-developed than in incipient-cyanobacterial biocrusts under both simulated and natural rainfall and on different spatial scales. Runoff yield decreased at coarser spatial scales due to re-infiltration along the hillslope, thus decreasing hydrological connectivity. Soil moisture monitoring at 0.03 m depth revealed higher moisture content and slower soil water loss in plots covered by cyanobacterial biocrusts compared to bare soils. Non-rainfall water inputs were also higher under well-developed cyanobacterial biocrusts than in bare soils. Disturbance of cyanobacterial biocrusts seriously affected the water balance by increasing runoff, decreasing soil moisture and accelerating soil water loss, at the same time that led to a very significant increase in sediment yield. The recovery of biocrust cover after disturbance can be relatively fast, but its growth rate is strongly conditioned by microclimate. The results of this paper show the important influence of cyanobacterial biocrust in modulating the different processes supporting the capacity of these ecosystems to provide key services such as water regulation or erosion control, and also the important impacts of their anthropic disturbance.

scholarly journals The Effect of Finite Heat Content and Thermal Diffusion on the Growth of a Sea-Ice Cover

1964 ◽  
Vol 5 (39) ◽  
pp. 315-324 ◽  
Author(s):  
Peter Schwerdtfeger
Keyword(s):  
Thermal Diffusivity ◽  
Sea Ice ◽  
Basic Equation ◽  
Heat Content ◽  
Ice Cover ◽  
Hudson Bay ◽  
Growth Equation ◽  
Ice Growth ◽  
Classical Work ◽  
Practical Analysis

AbstractThe practical analysis of the growth of a sea-ice cover is discussed with initial reference to the classical work of Stefan, whose basic equation connecting surface temperature with the growth of a uniform ice cover of negligible specific heat and hence infinite diffusivity is extended to cover “real” cases. The separate effects of a finite heat content and thermal diffusivity are derived theoretically and semi-empirically respectively, and combined in a more general ice-growth equation which is then tested in the analysis of annual sea-ice growth on Hudson Bay.

BIOLOGICAL AND OCEANOGRAPHIC CONDITIONS IN HUDSON BAY: 6. THE GENERAL HYDROGRAPHY AND HYDRODYNAMICS OF THE WATERS OF THE HUDSON BAY REGION

1932 ◽  
Vol 7 (1) ◽  
pp. 91-118 ◽  
Author(s):  
H. B. HACHEY
Keyword(s):  
Fresh Water ◽  
Water Movement ◽  
Open Ocean ◽  
Hudson Bay ◽  
Water Drainage ◽  
James Bay ◽  
Bay Area ◽  
Hydrographic Conditions ◽  
The Many ◽  
Oceanographic Conditions

The waters of Hudson bay differ markedly from the waters of Hudson strait and the waters of the open ocean. Intense stratification in the upper twenty-five metres, decreasing as the waters of the open ocean are approached, gives Hudson bay the character of a large estuary. Below fifty metres the waters are for all purposes dynamically dead, thus resulting in a cold saline body of water which probably undergoes very little change from season to season. The movements of the waters at various levels are dealt with to show that the inflow of waters from Fox channel and the many fresh-water drainage areas control the hydrographic conditions as found. The main water movement is from the James bay area to Hudson strait and thence to the open ocean.

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