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Peatlands are wetland ecosystems where net primary production exceeds organic matter decomposition. They are characterized by a near-surface water table controlled by a combination of internal and external processes, influenced by short-term meteorological and long-term climate variations among other factors. Site-specific conditions, such as peat hydrodynamic properties, surface vegetation patterns, and hydrogeological setting also substantially influence water table dynamics. The objective of this work was to characterize the influence of hydrogeological setting and meteorological conditions on water table depths (WTD) and on fluctuations therein in seven ombrotrophic peatlands in or near the St. Lawrence Lowlands (southern Quebec, Canada). Up-gradient, mid-gradient, and down-gradient locations were monitored in the seven peatlands, using dipwells with hourly WTD recordings. WTD was also monitored in the marginal minerotrophic zone found in three of the seven peatlands. Additionally, heads in the outflow (i.e., receiving diffused water from the peatland) and inflow (i.e., providing diffused water to the peatland) zones within the adjacent mineral deposits were monitored in seven and three peatlands respectively, using piezometers with hourly hydraulic head recordings. Hydraulic conductivities for the outflow zones ranged between 1.4*10-7 and 8.5*10-3 cm/s, whereas those of the inflow zones ranged between 5.6*10-7 and 3.9*10-6 cm/s. Evapotranspiration was shown to be the dominant factor controlling monthly cumulative water table decreases (MCD), while precipitation dominated the monthly cumulative water table increases (MCI). A strong correlation was found between mean peatland WTD and outflow zone hydraulic conductivity. Peatlands that were identified as being strongly connected with the adjacent mineral deposits in a diffuse underground outflow zone showed the greatest variations in water storage. This study highlights the importance of the connection between pea

This dissertation focused on using multiple water balance recharge methods within rehabilitated opencast mines at the Optimum Coal Mine, Mpumalanga,for the aim that a combination of water balance methods will yield more conclusive recharge from rainfall values within spoil material. It is known that different recharge methods yield very different results concerning recharge. New recharge methods were implemented based on the data received from the mine and compared to the recharge method already developed and proven to work. In the pursuit to solve the complicated issue of calculating recharge from rainfall, four newly formulated methods were produced, called the Rainfall Infiltrated Volume, Stage Curve Volume, Dry and Wet Calculations and Recharge from Stage Curve Volume. These methods were compared to wellknown recharge methods which included the Saturated Volume Fluctuation, Cumulative Rainfall Departure and Water Table Fluctuation methods over a fiveyear period. These methods, combined, narrowed the range between the minimum and maximum recharge values, usually estimated for the study area, and in the process provided a better understanding of the water management systems in this area. Pit Volume Calculations yielded a 25% void space for spoils, which were used in the recharge calculations. Each method yielded a minimum and maximum recharge value from rainfall, but not all of them produced the results expected from the area. The Zevenfontein opencast rehabilitated pit produced very accurate and believable recharge from rainfall at 18–20% for the new recharge methods and 15–17% for the known recharge methods. The Optimus opencast rehabilitated pit had numerous problems, but in the end also produced believable results at 25–30% for the new recharge methods and 15–20% for the known recharge methods. Thus, it was concluded that a combination of recharge methods yielded more conclusive recharge values.

In the eastern Thuringian Basin, the low precipitation rate of 585 mm/y limits the groundwater resources in the sandstone aquifer system. The aim of this study was to develop a groundwater flow model for the region in order to forecast the impacts of different climate scenarios on the groundwater balance. Since recharge is of high relevance for the numerical model, a time series of groundwater levels were investigated to obtain the recharge input function. In the sandstone aquifer it could be shown that groundwater flow is characterised by flow in the fracture network as well as in the matrix. The largest fraction of recharge reaches the water table very quickly via the fracture network. However, both the thickness of the unsaturated zone and the low hydraulic conductivity of the sandstone matrix control the time lag of groundwater recharge. The time lag of the slow component to reach the water table is in the order of several years

Peat specific yield (Sy) is an important parameter involved in many peatland hydrological functions such as flood attenuation, baseflow contribution to rivers, and maintaining groundwater levels in surficial aquifers. However, general knowledge on peatland water storage capacity is still very limited, due in part to the technical difficulties related to in situ measurements. The objectives of this study were to quantify vertical Sy variations of water tables in peatlands using the water table fluctuation (WTF) method and to better understand the factors controlling peatland water storage capacity. The method was tested in five ombrotrophic peatlands located in the St. Lawrence Lowlands (southern Québec, Canada). In each peatland, water table wells were installed at three locations (up-gradient, mid-gradient, and down-gradient). Near each well, a 1-m long peat core (8 cm × 8 cm) was sampled, and subsamples were used to determine SY with standard gravitational drainage method. A larger peat sample (25 cm × 60 cm × 40 cm) was also collected in one peatland to estimate Sy using a laboratory drainage method. In all sites, the mean water table depth ranged from 9 to 49 cm below the peat surface, with annual fluctuations varying between 15 and 29 cm for all locations. The WTF method produced similar results to the gravitational drainage experiments, with values ranging between 0.13 and 0.99 for the WTF method and between 0.01 and 0.95 for the gravitational drainage experiments. Sy was found to rapidly decrease with depth within 20 cm, independently of the within-site location and the mean annual water table depth. Dominant factors explaining Sy variations were identified using analysis of variance. The most important factor was peatland site, followed by peat depth and seasonality. Variations in storage capacity considering site and seasonality followed regional effective growing degree days and evapotranspiration patterns. This work provides new data on spatial variations

Peat specific yield (Sy) is an important parameter involved in many peatland hydrological functions such as flood attenuation, baseflow contribution to rivers, and maintaining groundwater levels in surficial aquifers. However, general knowledge on peatland water storage capacity is still very limited, due in part to the technical difficulties related to in situ measurements. The objectives of this study were to quantify vertical Sy variations of water tables in peatlands using the water table fluctuation (WTF) method and to better understand the factors controlling peatland water storage capacity. The method was tested in five ombrotrophic peatlands located in the St. Lawrence Lowlands (southern Québec, Canada). In each peatland, water table wells were installed at three locations (up-gradient, mid-gradient, and down-gradient). Near each well, a 1-m long peat core (8 cm × 8 cm) was sampled, and subsamples were used to determine SY with standard gravitational drainage method. A larger peat sample (25 cm × 60 cm × 40 cm) was also collected in one peatland to estimate Sy using a laboratory drainage method. In all sites, the mean water table depth ranged from 9 to 49 cm below the peat surface, with annual fluctuations varying between 15 and 29 cm for all locations. The WTF method produced similar results to the gravitational drainage experiments, with values ranging between 0.13 and 0.99 for the WTF method and between 0.01 and 0.95 for the gravitational drainage experiments. Sy was found to rapidly decrease with depth within 20 cm, independently of the within-site location and the mean annual water table depth. Dominant factors explaining Sy variations were identified using analysis of variance. The most important factor was peatland site, followed by peat depth and seasonality. Variations in storage capacity considering site and seasonality followed regional effective growing degree days and evapotranspiration patterns. This work provides new data on spatial variations

Peatlands are wetland ecosystems where net primary production exceeds organic matter decomposition. They are characterized by a near-surface water table controlled by a combination of internal and external processes, influenced by short-term meteorological and long-term climate variations among other factors. Site-specific conditions, such as peat hydrodynamic properties, surface vegetation patterns, and hydrogeological setting also substantially influence water table dynamics. The objective of this work was to characterize the influence of hydrogeological setting and meteorological conditions on water table depths (WTD) and on fluctuations therein in seven ombrotrophic peatlands in or near the St. Lawrence Lowlands (southern Quebec, Canada). Up-gradient, mid-gradient, and down-gradient locations were monitored in the seven peatlands, using dipwells with hourly WTD recordings. WTD was also monitored in the marginal minerotrophic zone found in three of the seven peatlands. Additionally, heads in the outflow (i.e., receiving diffused water from the peatland) and inflow (i.e., providing diffused water to the peatland) zones within the adjacent mineral deposits were monitored in seven and three peatlands respectively, using piezometers with hourly hydraulic head recordings. Hydraulic conductivities for the outflow zones ranged between 1.4*10-7 and 8.5*10-3 cm/s, whereas those of the inflow zones ranged between 5.6*10-7 and 3.9*10-6 cm/s. Evapotranspiration was shown to be the dominant factor controlling monthly cumulative water table decreases (MCD), while precipitation dominated the monthly cumulative water table increases (MCI). A strong correlation was found between mean peatland WTD and outflow zone hydraulic conductivity. Peatlands that were identified as being strongly connected with the adjacent mineral deposits in a diffuse underground outflow zone showed the greatest variations in water storage. This study highlights the importance of the connection between pea

Peat specific yield (Sy) is an important parameter involved in many peatland hydrological functions such as flood attenuation, baseflow contribution to rivers, and maintaining groundwater levels in surficial aquifers. However, general knowledge on peatland water storage capacity is still very limited, due in part to the technical difficulties related to in situ measurements. The objectives of this study were to quantify vertical Sy variations of water tables in peatlands using the water table fluctuation (WTF) method and to better understand the factors controlling peatland water storage capacity. The method was tested in five ombrotrophic peatlands located in the St. Lawrence Lowlands (southern Québec, Canada). In each peatland, water table wells were installed at three locations (up-gradient, mid-gradient, and down-gradient). Near each well, a 1-m long peat core (8 cm × 8 cm) was sampled, and subsamples were used to determine SY with standard gravitational drainage method. A larger peat sample (25 cm × 60 cm × 40 cm) was also collected in one peatland to estimate Sy using a laboratory drainage method. In all sites, the mean water table depth ranged from 9 to 49 cm below the peat surface, with annual fluctuations varying between 15 and 29 cm for all locations. The WTF method produced similar results to the gravitational drainage experiments, with values ranging between 0.13 and 0.99 for the WTF method and between 0.01 and 0.95 for the gravitational drainage experiments. Sy was found to rapidly decrease with depth within 20 cm, independently of the within-site location and the mean annual water table depth. Dominant factors explaining Sy variations were identified using analysis of variance. The most important factor was peatland site, followed by peat depth and seasonality. Variations in storage capacity considering site and seasonality followed regional effective growing degree days and evapotranspiration patterns. This work provides new data on spatial variations

Peat specific yield (Sy) is an important parameter involved in many peatland hydrological functions such as flood attenuation, baseflow contribution to rivers, and maintaining groundwater levels in surficial aquifers. However, general knowledge on peatland water storage capacity is still very limited, due in part to the technical difficulties related to in situ measurements. The objectives of this study were to quantify vertical Sy variations of water tables in peatlands using the water table fluctuation (WTF) method and to better understand the factors controlling peatland water storage capacity. The method was tested in five ombrotrophic peatlands located in the St. Lawrence Lowlands (southern Québec, Canada). In each peatland, water table wells were installed at three locations (up-gradient, mid-gradient, and down-gradient). Near each well, a 1-m long peat core (8 cm × 8 cm) was sampled, and subsamples were used to determine SY with standard gravitational drainage method. A larger peat sample (25 cm × 60 cm × 40 cm) was also collected in one peatland to estimate Sy using a laboratory drainage method. In all sites, the mean water table depth ranged from 9 to 49 cm below the peat surface, with annual fluctuations varying between 15 and 29 cm for all locations. The WTF method produced similar results to the gravitational drainage experiments, with values ranging between 0.13 and 0.99 for the WTF method and between 0.01 and 0.95 for the gravitational drainage experiments. Sy was found to rapidly decrease with depth within 20 cm, independently of the within-site location and the mean annual water table depth. Dominant factors explaining Sy variations were identified using analysis of variance. The most important factor was peatland site, followed by peat depth and seasonality. Variations in storage capacity considering site and seasonality followed regional effective growing degree days and evapotranspiration patterns. This work provides new data on spatial variations