scholarly journals Modelling the hydrological interactions between a fissured granite aquifer and a valley mire in the Massif Central, France

2020 ◽  
Author(s):  
Arnaud Duranel ◽  
Julian R. Thompson ◽  
Helene Burningham ◽  
Philippe Durepaire ◽  
Stéphane Garambois ◽  
...  
Keyword(s):  
Water Balance ◽  
Variation Partitioning ◽  
Model Performance ◽  
Critical Element ◽  
Seepage Rate ◽  
Massif Central ◽  
Groundwater Seepage ◽  
Groundwater Levels ◽  
Mineral Soils

Abstract. The contribution of groundwater to the hydrology of hard rock regions has long been assumed to be small. This is being progressively challenged and conceptual hydrological models of headwater wetlands in these regions may need to be revised. We developed a high-resolution MIKE SHE/MIKE 11 model of a 231.3 ha headwater catchment in the granitic uplands of the French Massif Central to estimate the contribution of groundwater upwelling to the water balance of the Dauges mire, an acidic valley mire of international importance for nature conservation. We estimated that groundwater upwelling from the underlying granite weathering formations – mostly an approximately 55  m deep fissured zone – provides 27.1 % of total long-term inflows to the mire. This contribution increases to 37.2 % in September when total inflows are small. Overland boundary inflow accounts for an average of 40.2 % of total inflows. However most of this originates from groundwater seepage through mineral soils along the mire margins or in small unchannelized valleys upslope of the mire. A sensitivity analysis showed that model performance in terms of the simulation of mire groundwater levels was most sensitive to parameters describing the mineral soils and granite weathered formations rather than the overlying peat layer. Variation partitioning showed that groundwater upwelling was the most important factor driving simulated monthly groundwater table depth within the mire. Sustained groundwater upwelling maintains the mire water table close to or at ground level for most of the year. As a result, precipitation and overland boundary inflows are mostly evacuated as saturation-excess runoff. There was close agreement between the observed distribution of mire habitats and areas where the simulated long-term groundwater seepage rate was larger than zero in September. Groundwater upwelling from the underlying weathered formations can be a quantitatively important and functionally critical element of the water balance of valley mires in granitic headwater catchments. These results have important legal and management implications.

scholarly journals Modelling the hydrological interactions between a fissured granite aquifer and a valley mire in the Massif Central, France

2021 ◽  
Vol 25 (1) ◽  
pp. 291-319
Author(s):  
Arnaud Duranel ◽  
Julian R. Thompson ◽  
Helene Burningham ◽  
Philippe Durepaire ◽  
Stéphane Garambois ◽  
...  
Keyword(s):  
Water Balance ◽  
Variation Partitioning ◽  
Critical Element ◽  
Small Contribution ◽  
Seepage Rate ◽  
Massif Central ◽  
Groundwater Seepage ◽  
Weathered Granite ◽  
Mineral Soils

Abstract. We developed a high-resolution MIKE SHE/MIKE 11 model of a 231.3 ha headwater catchment in the granitic uplands of the French Massif Central to estimate the contribution of groundwater upwelling to the water balance of the Dauges mire, an acidic valley mire of international importance for nature conservation. We estimated that groundwater upwelling from the underlying weathered granite formations – mostly an approximately 55 m deep fissured zone – provides 27.1 % of total long-term inflows to the mire. This contribution increases to 37.2 % in September when total inflows are small. Overland boundary inflow accounts for an average of 40.2 % of total inflows. However, most of this originates from groundwater seepage through mineral soils along the mire margins or in small non-channelised valleys upslope of the mire. A sensitivity analysis showed that model performance in terms of the simulation of mire groundwater levels was most sensitive to parameters describing the mineral soils and weathered granite formations rather than the overlying peat layer. Variation partitioning demonstrated that groundwater upwelling was the most important factor driving simulated monthly groundwater table depth within the mire. Sustained groundwater upwelling maintains the mire water table close to or at ground level for most of the year. As a result, precipitation and overland boundary inflows quickly leave the wetland as saturation-excess runoff. There was close agreement between the observed distribution of mire habitats and areas where the simulated long-term groundwater seepage rate was larger than zero in September. Our results demonstrate that, contrary to the assumed small contribution of groundwater to the hydrology of hard-rock regions, groundwater upwelling from underlying weathered formations can be a quantitatively important and functionally critical element of the water balance of valley mires in granitic headwater catchments. These results have important legal and management implications.

scholarly journals The feasibility of using soil runoff in calculating the water balance of ameliorated soil

2021 ◽  
Vol 285 ◽  
pp. 06003
Author(s):  
Ivan Levshunov ◽  
Yuri Mazhayskiy ◽  
Olga Chernikova
Keyword(s):  
Water Balance ◽  
Surface Runoff ◽  
Water Regime ◽  
Field Experiments ◽  
Initial Moisture Content ◽  
Field Research ◽  
Groundwater Levels ◽  
Agricultural Use ◽  
Term Field

The water regime on the reclaimed lands changes significantly during the year, and its possible change must be established or predicted in advance at the project stage. From the main characteristics of the water regime of soil, it is possible to reliably predict changes in moisture reserves and, worse, the dynamics of groundwater levels. Prediction of changes in moisture reserves in soil is carried out using “water balance calculations”. The results of long-term field research have shown that the main factors causing surface runoff are: the amount and intensity of precipitation, the initial moisture content of the upper soil layers, the slope and condition (agricultural use) of the site surface. The feasibility of using a variable runoff boundary in calculating the water balance of ameliorated soil is shown. The results of field experiments on the study of surface runoff in conditions of loamy soil are presented. Two-factor dependences of the daily runoff from precipitation and soil moisture have been obtained in case of its various agricultural uses.

scholarly journals Seasonal effects of controlled drainage on field water balance and groundwater levels

2021 ◽  
Author(s):  
Heidi Salo ◽  
Aleksi Salla ◽  
Harri Koivusalo
Keyword(s):  
Water Management ◽  
Water Balance ◽  
Model Performance ◽  
Shallow Groundwater ◽  
Seasonal Effects ◽  
Controlled Drainage ◽  
Management Options ◽  
Data Set ◽  
Groundwater Levels ◽  
Field Water Balance

Abstract Adaptive water management solutions such as controlled drainage have raised interest in Nordic areas due to climate variability. It is not fully known how controlled drainage affects seasonal field water balance or can help in preventing water scarcity during dry growing seasons (GSs). The objective was to simulate the effects of controlled drainage on field hydrology using a well-tested, process-based hydrological model. The FLUSH model was calibrated and validated to an experimental field. The model performance with non-local input data was moderate but acceptable for running the controlled drainage scenarios to test the response of the water management method to meteorological forcing. Simulation results showed that controlled drainage reduced drain discharge while increasing surface layer runoff and shallow groundwater outflow. Groundwater depths from the scenario simulations demonstrated that controlled drainage could keep the depth closer to the soil surface, but the effect diminished during the dry conditions. Controlled drainage can be used to change the water flow pathways but has a secondary effect compared with the primary meteorological drivers. The field data set and FLUSH formed a novel computational platform to study the impacts of different water management options on the whole water balance and spatial variability of groundwater depths.

Evaluating water balance components for forested headwater catchment undergoing environmental changes

2020 ◽  
Author(s):  
Veronika Mikesova ◽  
Michal Dohnal ◽  
Jana Votrubova ◽  
Tomas Vogel
Keyword(s):  
Water Balance ◽  
Environmental Changes ◽  
Water Storage ◽  
Current Status ◽  
Catchment Scale ◽  
Water Balance Components ◽  
Groundwater Levels ◽  
Interception Loss ◽  
Headwater Catchment

<p>Evaluating seasonal and long-term variations in water balance at catchment scale can be useful for assessing the current status and trends in water resources availability. Components of water balance reflect meteorological and climate variability, and vegetation cover development.</p><p>The experimental catchment Uhlířská is a small forested headwater catchment in the Jizera Mountains, Czech Republic. The catchment was extensively deforested in the 80´s. Damaged trees long exposed to the effects of air pollutants were poorly resistant to wind and pests. In the 90´s, new spruce forest was planted. The catchment has been subject to long-term monitoring. The 19-year series of data including air temperature, rain and snow precipitation, discharge, groundwater levels, wind velocity, and air humidity, is examined.</p><p>Our study provides basic analysis of directly measured components of water balance (precipitation and discharge, annual and seasonal runoff coefficients). The study further deals with the evaluation of the unmeasured components of the water balance (evapotranspiration and water storage). An interception model was employed to calculate the interception loss. Potential evaporation and transpiration during vegetation seasons were estimated by Penman and Penman-Monteith methods. Snow sublimation was estimated in the winter seasons. Effect of the forest development during the period of interest was considered.</p><p>The catchment water balance equation suggests significant changes of the water storage over the observation period, implying its decrease in recent years. However, baseflow and deep water storage seem to be unchanged. This discrepancy could be partly attributed to the decrease in shallow water storage and/or more pronounced transpiration reduction in recent vegetation seasons.</p><p>The research is supported by the Czech Science Foundation Project No. 20-00788S.</p>

An Investigation of the Quantity, Quality and Sources of Groundwater Seepage into the St. Clair River near Sarnia, Ontario, Canada

1986 ◽  
Vol 21 (3) ◽  
pp. 351-367 ◽  
Author(s):  
Michael Sklash ◽  
Sharon Mason ◽  
Suzanne Scott ◽  
Chris Pugsley
Keyword(s):  
Electrical Conductivity ◽  
River Water ◽  
Organic Contaminants ◽  
Shallow Groundwater ◽  
Seepage Rate ◽  
Groundwater Seepage ◽  
Seepage Meters ◽  
Groundwater Samples ◽  
Hydraulic Gradients ◽  
Unidentified Source

Abstract We used seepage meters and minipiezometers to survey a 100 m by 7 km band of streambed of the St. Clair River near Sarnia, Ontario, Canada, to determine the quantity, quality, and sources of groundwater seepage into the river. The average observed seepage rate, 1.4 x 10−8 m3/s/m2, suggests higher than expected hydraulic conductivities and/or hydraulic gradients in the streambed. We found detectable levels of some organic contaminants in streambed groundwater samples from 1.0 and 1.5 m depths, however , concentrations did not exceed drinking water guidelines. Our isotopic and electrical conductivity data indicate that: (l) the streambed groundwater is not just river water, (2) groundwater from the “freshwater aquifer” at the base of the overburden Is not a significant component of the streambed groundwater, (3) some of the streambed groundwater is partially derived from a shallow groundwater flow system, and (4) an unidentified source of water with low tritium, river water-like δ18O, and very high electrical conductivity, contributes to the streambed groundwater.

Effect of Long-Term Simulated Weightlessness on Surfactant and Water Balance in Mouse Lungs

2013 ◽  
Vol 155 (3) ◽  
pp. 306-308
Author(s):  
I. G. Bryndina ◽  
N. N. Vasilieva ◽  
Yu. A. Krivonogova ◽  
V. M. Baranov
Keyword(s):  
Water Balance ◽  
Simulated Weightlessness ◽  
Mouse Lungs

scholarly journals Effects of experimental nitrogen deposition on peatland carbon pools and fluxes: a modelling analysis

2015 ◽  
Vol 12 (1) ◽  
pp. 79-101 ◽  
Author(s):  
Y. Wu ◽  
C. Blodau ◽  
T. R. Moore ◽  
J. Bubier ◽  
S. Juutinen ◽  
...  
Keyword(s):  
Ecosystem Respiration ◽  
Model Performance ◽  
Net Ecosystem Exchange ◽  
N Fertilization ◽  
N Deposition ◽  
Competitive Advantages ◽  
Long Term Effects ◽  
N Content ◽  
Modelling Analysis

Abstract. Nitrogen (N) pollution of peatlands alters their carbon (C) balances, yet long-term effects and controls are poorly understood. We applied the model PEATBOG to explore impacts of long-term nitrogen (N) fertilization on C cycling in an ombrotrophic bog. Simulations of summer gross ecosystem production (GEP), ecosystem respiration (ER) and net ecosystem exchange (NEE) were evaluated against 8 years of observations and extrapolated for 80 years to identify potential effects of N fertilization and factors influencing model behaviour. The model successfully simulated moss decline and raised GEP, ER and NEE on fertilized plots. GEP was systematically overestimated in the model compared to the field data due to factors that can be related to differences in vegetation distribution (e.g. shrubs vs. graminoid vegetation) and to high tolerance of vascular plants to N deposition in the model. Model performance regarding the 8-year response of GEP and NEE to N input was improved by introducing an N content threshold shifting the response of photosynthetic capacity (GEPmax) to N content in shrubs and graminoids from positive to negative at high N contents. Such changes also eliminated the competitive advantages of vascular species and led to resilience of mosses in the long-term. Regardless of the large changes of C fluxes over the short-term, the simulated GEP, ER and NEE after 80 years depended on whether a graminoid- or shrub-dominated system evolved. When the peatland remained shrub–Sphagnum-dominated, it shifted to a C source after only 10 years of fertilization at 6.4 g N m−2 yr−1, whereas this was not the case when it became graminoid-dominated. The modelling results thus highlight the importance of ecosystem adaptation and reaction of plant functional types to N deposition, when predicting the future C balance of N-polluted cool temperate bogs.

scholarly journals Variations of global and continental water balance components as impacted by climate forcing uncertainty and human water use

2016 ◽  
Vol 20 (7) ◽  
pp. 2877-2898 ◽  
Author(s):  
Hannes Müller Schmied ◽  
Linda Adam ◽  
Stephanie Eisner ◽  
Gabriel Fink ◽  
Martina Flörke ◽  
...  
Keyword(s):  
Water Resources ◽  
Water Balance ◽  
Water Use ◽  
Climate Forcing ◽  
Land Area ◽  
Water Balance Components ◽  
Climate Forcings ◽  
The Impact ◽  
Global Water

Abstract. When assessing global water resources with hydrological models, it is essential to know about methodological uncertainties. The values of simulated water balance components may vary due to different spatial and temporal aggregations, reference periods, and applied climate forcings, as well as due to the consideration of human water use, or the lack thereof. We analyzed these variations over the period 1901–2010 by forcing the global hydrological model WaterGAP 2.2 (ISIMIP2a) with five state-of-the-art climate data sets, including a homogenized version of the concatenated WFD/WFDEI data set. Absolute values and temporal variations of global water balance components are strongly affected by the uncertainty in the climate forcing, and no temporal trends of the global water balance components are detected for the four homogeneous climate forcings considered (except for human water abstractions). The calibration of WaterGAP against observed long-term average river discharge Q significantly reduces the impact of climate forcing uncertainty on estimated Q and renewable water resources. For the homogeneous forcings, Q of the calibrated and non-calibrated regions of the globe varies by 1.6 and 18.5 %, respectively, for 1971–2000. On the continental scale, most differences for long-term average precipitation P and Q estimates occur in Africa and, due to snow undercatch of rain gauges, also in the data-rich continents Europe and North America. Variations of Q at the grid-cell scale are large, except in a few grid cells upstream and downstream of calibration stations, with an average variation of 37 and 74 % among the four homogeneous forcings in calibrated and non-calibrated regions, respectively. Considering only the forcings GSWP3 and WFDEI_hom, i.e., excluding the forcing without undercatch correction (PGFv2.1) and the one with a much lower shortwave downward radiation SWD than the others (WFD), Q variations are reduced to 16 and 31 % in calibrated and non-calibrated regions, respectively. These simulation results support the need for extended Q measurements and data sharing for better constraining global water balance assessments. Over the 20th century, the human footprint on natural water resources has become larger. For 11–18% of the global land area, the change of Q between 1941–1970 and 1971–2000 was driven more strongly by change of human water use including dam construction than by change in precipitation, while this was true for only 9–13 % of the land area from 1911–1940 to 1941–1970.

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