Design measures to mitigate the impact of shallow groundwater on hydrologic performance of permeable pavements

2020 ◽  
Vol 34 (25) ◽  
pp. 5146-5166
Author(s):  
Kun Zhang ◽  
Ting Fong May Chui
2005 ◽  
Vol 42 (5) ◽  
pp. 1377-1390 ◽  
Author(s):  
Matthew D Alexander ◽  
Kerry TB MacQuarrie

Accurate measurements of in situ groundwater temperature are important in many groundwater investigations. Temperature is often measured in the subsurface using an access tube in the form of a piezometer or monitoring well. The impact of standpipe materials on the conduction of heat into the subsurface has not previously been examined. This paper reports on the results of a laboratory experiment and a field experiment designed to determine if different standpipe materials or monitoring instrument configurations preferentially conduct heat into the shallow sub surface. Simulations with a numerical model were also conducted for comparison to the laboratory results. Statistical analysis of the laboratory results demonstrates that common standpipe materials, such as steel and polyvinylchloride (PVC), do not affect temperature in the subsurface. Simulations with a finite element flow and heat transport model also confirm that the presence of access tube materials does not affect shallow groundwater temperature measurements. Field results show that different instrument configurations, such as piezometers and water and air filled and sealed well points, do not affect subsurface temperature measurements.Key words: groundwater temperature, temperature measurement, conduction, piezometers, piezometer standpipes, thermal modelling.


2013 ◽  
Vol 17 (4) ◽  
pp. 1379-1391 ◽  
Author(s):  
A. H. Aubert ◽  
C. Gascuel-Odoux ◽  
G. Gruau ◽  
N. Akkal ◽  
M. Faucheux ◽  
...  

Abstract. High-frequency, long-term and multisolute measurements are required to assess the impact of human pressures on water quality due to (i) the high temporal and spatial variability of climate and human activity and (ii) the fact that chemical solutes combine short- and long-term dynamics. Such data series are scarce. This study, based on an original and unpublished time series from the Kervidy-Naizin headwater catchment (Brittany, France), aims to determine solute transfer processes and dynamics that characterise this strongly human-impacted catchment. The Kervidy-Naizin catchment is a temperate, intensive agricultural catchment, hydrologically controlled by shallow groundwater. Over 10 yr, five solutes (nitrate, sulphate, chloride, and dissolved organic and inorganic carbon) were monitored daily at the catchment outlet and roughly every four months in the shallow groundwater. The concentrations of all five solutes showed seasonal variations but the patterns of the variations differed from one solute to another. Nitrate and chloride exhibit rather smooth variations. In contrast, sulphate as well as organic and inorganic carbon is dominated by flood flushes. The observed nitrate and chloride patterns are typical of an intensive agricultural catchment hydrologically controlled by shallow groundwater. Nitrate and chloride originating mainly from organic fertilisers accumulated over several years in the shallow groundwater. They are seasonally exported when upland groundwater connects with the stream during the wet season. Conversely, sulphate as well as organic and inorganic carbon patterns are not specific to agricultural catchments. These solutes do not come from fertilisers and do not accumulate in soil or shallow groundwater; instead, they are biogeochemically produced in the catchment. The results allowed development of a generic classification system based on the specific temporal patterns and source locations of each solute. It also considers the stocking period and the dominant process that limits transport to the stream, i.e. the connectivity of the stocking compartment. This mechanistic classification can be applied to any chemical solute to help assess its origin, storage or production location and transfer mechanism in similar catchments.


2004 ◽  
Vol 8 (3) ◽  
pp. 503-520 ◽  
Author(s):  
C. Neal ◽  
B. Reynolds ◽  
M. Neal ◽  
H. Wickham ◽  
L. Hill ◽  
...  

Abstract. Results for long term water quality monitoring are described for the headwaters of the principal headwater stream of the River Severn, the Afon Hafren. The results are linked to within-catchment information to describe the influence of conifer harvesting on stream and shallow groundwater quality. A 19-year record of water quality data for the Hafren (a partially spruce forested catchment with podzolic soil) shows the classic patterns of hydrochemical change in relation to concentration and flow responses for upland forested systems. Progressive felling of almost two-thirds of the forest over the period of study resulted in little impact from harvesting and replanting in relation to stream water quality. However, at the local scale, a six years’ study of felling indicated significant release of nitrate into both surface and groundwater; this persisted for two or three years before declining. The study has shown two important features. Firstly, phased felling has led to minimal impacts on stream water. This contrasts with the results of an experimental clear fell for the adjacent catchment of the Afon Hore where a distinct water quality deterioration was observed for a few years. Secondly, there are localised zones with varying hydrology that link to groundwater sources with fracture flow properties. This variability makes extrapolation to the catchment scale difficult without very extensive monitoring. The implications of these findings are discussed in relation to strong support for the use of phased felling-based management of catchments and the complexities of within catchment processes. Keywords: deforestation, water quality, acidification, pH, nitrate, alkalinity, ANC, aluminium, dissolved organic carbon, Plynlimon, forest, spruce, Afon Hafren, podzol


2012 ◽  
Vol 9 (8) ◽  
pp. 9715-9741 ◽  
Author(s):  
A. H. Aubert ◽  
C. Gascuel-Odoux ◽  
G. Gruau ◽  
J. Molénat ◽  
M. Faucheux ◽  
...  

Abstract. Assessing the impact of human pressures on water quality is difficult. First, there is a high temporal and spatial variability of climate and human activity. Second, chemical elements have their own characteristics mixing short and long term dynamics. High frequency, long-term and multi-element measurements are required. But, such data series are scarce. This paper aims at determining what the hydro-chemical particularities of a livestock farming catchment are in a temperate climatic context. It is based on an original and never published time series, from Kervidy-Naizin headwater catchment. Stream chemistry was monitored daily and shallow groundwater roughly every four month, for 10 yr and five elements (nitrate, sulphate, chloride, and dissolved organic and inorganic carbon). The five elements present strong but different seasonal patterns. Nitrate and chloride present a seasonal flush, all along or at the beginning of the wet season, respectively. Sulphate, organic and inorganic carbon present storm flushes, with constant or decreasing peaks throughout the wet season. These depicted nitrate and chloride patterns are typical of a livestock farming catchment. There, nitrate and chloride coming from organic fertilisation have been accumulating over years in the shallow groundwater. They are seasonally flushed when the groundwater connects to the stream. Sulphate, organic and inorganic carbon patterns do not seem specific to agricultural catchments. These elements are produced each year and flushed by storms. Finally, a generic classification of temporal patterns and elements is established for agricultural catchments. It is based on the distance of the source component to the stream and the dominant controlling process (accumulation versus production). This classification could be applied to any chemical element and help assessing the level of water disturbances.


Geofluids ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-21
Author(s):  
Zhaoxu Mi ◽  
Fugang Wang ◽  
Zhijie Yang ◽  
Xufeng Li ◽  
Yujie Diao ◽  
...  

CO2 geological storage in deep saline aquifers is an effective way to reduce CO2 emissions. The injection of CO2 inevitably causes a significant pressure increase in reservoirs. When there exist faults which cut through a deep reservoir and shallow aquifer system, there is a risk of the shallow aquifer being impacted by the changes in reservoir hydrodynamic fields. In this paper, a radial model and a 3D model are established by TOUGH2-ECO2N for the reservoir system in the CO2 geological storage demonstration site in the Junggar Basin to analyze the impact of the CO2 injection on the deep reservoir pressure field and the possible influence on the surrounding shallow groundwater sources. According to the results, the influence of CO2 injection on the reservoir pressure field in different periods and different numbers of well is analyzed. The result shows that the number of injection wells has a significant impact on the reservoir pressure field changes. The greater the number of injection wells is, the greater the pressure field changes. However, after the cessation of CO2 injection, the number of injection wells has little impact on the reservoir pressure recovery time. Under the geological conditions of the site and the constant injection pressure, although the CO2 injection has a significant influence on the pressure field in the deep reservoir, the impact on the shallow groundwater source area is minimal and can be neglected and the existing shallow groundwater sources are safe in the given project scenarios.


2011 ◽  
Vol 91 (2) ◽  
pp. 211-221 ◽  
Author(s):  
Priyantha B. Kulasekera ◽  
Gary W. Parkin

Kulasekera, P. B. and Parkin, G. W. 2011. Influence of the shape of inter-horizon boundary and size of soil tongues on preferential flow under shallow groundwater conditions: A simulation study. Can. J. Soil Sci. 91: 211–221. Detailed studies of the impact of soil tongues at soil horizon interfaces are very important in understanding preferential flow processes through layered soils and in improving the accuracy of models predicting water and solute transport through the vadose zone. The implication of having soil tongues of different shapes and sizes created at the soil horizon interface on solute transport through a layered soil horizon was studied by simulating water and solute transport using the VS2DI model. This 2-D simulation study reconfirmed that soil tongues facilitate preferential flow, and the level of activeness of tongues may depend on the number of soil tongues, their spacing and distribution. Also, the size of the soil tongues (length and diameter at the interface between the soil horizons) and their shape influence the rate of preferential flow. Increasing tongue length consistently resulted in an increase in solute velocity across the entire soil profile regardless of the tongue shape; for example, a soil tongue of 0.25 m length increased solute velocity by about 1.5 times over a soil profile without tongues, but this increase might be different for soil types and groundwater conditions other than those considered in this study. Narrowing of tongues increased solute velocity, whereas increasing the number of tongues in a wider soil profile decreased the solute-front's velocity. As tongue length increased, the area containing solutes at prescribed elapsed times decreased. An implication of this study is that soil horizon tongue shape and spacing reduce pollutant residence times, hence inter-horizon boundary morphology should be considered when modelling transport through the vadose zone. As well, since the solute velocity behaviours of a triangular- and a wider rectangular-shaped tongue were nearly identical, simply measuring solute velocity in the field will reveal little information on the shape of a soil tongue.


2013 ◽  
Vol 68 (9) ◽  
pp. 1950-1958 ◽  
Author(s):  
Jennifer Drake ◽  
Andrea Bradford

Permeable pavements (PPs) have been in use as stormwater management systems in Canada and the United States for over 20 years. After years of exposure to sediment and debris build-up, surface clogging reduces the infiltration of stormwater and inhibits the hydraulic and environmental functions of the pavement. Removal of surface material has been shown to restore infiltration but the majority of studies have been limited to small-scale testing. This paper presents the results of small- and full-sized equipment testing aimed at restoring surface permeability, including the first testing of regenerative-air and vacuum-sweeping streetsweepers in Ontario. Maintenance achieved partial restoration of PP surface permeability. Post-treatment surface infiltration rates displayed large spatial variability, highlighting that localized conditions throughout the pavement have a confounding influence on the overall effectiveness of maintenance. The impact of maintenance may be improved by establishing regular cleaning intervals and developing instructional guidelines for pavement owners and equipment operators.


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