Stream water quality in acid sensitive UK upland areas; an example of potential water quality remediation based on groundwater manipulation.

Abstract. The patterns of variation in water quality for an acidic stream draining plantation forest overlying acidic and acid sensitive gley soils with shale and slate bedrock changed following the introduction of a 45 m deep borchole near to the stream. During drilling, air flushing of debris from the borehole cleared fracture routes for groundwater penetration to the stream via the stream bed. Consequently, there were and there remain marked increases in pH, alkalinity and calcium concentrations in the stream water. The extent of this water quality improvement varies according to flow. Under extreme highfiow conditions, most of the stream water is supplied from near surface soil water sources and acidic stream waters (pH about 4.2) result. Under baseflow conditions, the stream water pH is about 7.0 upstream and about 7.5 downstream of the borehole. Under intermediate flow conditions, the improvement in pH is most marked and values increase from around 5 to around 6.3. For acid sensitive 'hard rock' areas such as those studied here, the bedrock has frequently been assumed to be both impermeable and low in base cations. This study illustrates that this view may be incorrect, and that groundwater may provide an important modifier of streamwater quality, at least for slate and shale dominated hard rock areas. Indeed, the work demonstrates clearly the potential for water quality remediation through groundwater manipulation.

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Surface water process and groundwater flow within a hydrologically complex floodplain wetland, Norfolk Broads, U.K.

Hydrology and Earth System Sciences ◽

10.5194/hess-1-115-1997 ◽

1997 ◽

Vol 1 (1) ◽

pp. 115-135 ◽

Cited By ~ 8

Author(s):

D. J. Gilvear ◽

P. J. K. Sadler ◽

J. H. Tellam ◽

J. W. Lloyd

Keyword(s):

Water Quality ◽

Hard Rock ◽

Stream Water ◽

Base Cations ◽

Flow Conditions ◽

Plantation Forest ◽

Near Surface ◽

Water Ph ◽

Norfolk Broads ◽

Stream Waters

Abstract. The patterns of variation in water quality for an acidic stream draining plantation forest overlying acidic and acid sensitive gley soils with shale and slate bedrock changed following the introduction of a 45 m deep borchole near to the stream. During drilling, air flushing of debris from the borehole cleared fracture routes for groundwater penetration to the stream via the stream bed. Consequently, there were and there remain marked increases in pH, alkalinity and calcium concentrations in the stream water. The extent of this water quality improvement varies according to flow. Under extreme highfiow conditions, most of the stream water is supplied from near surface soil water sources and acidic stream waters (pH about 4.2) result. Under baseflow conditions, the stream water pH is about 7.0 upstream and about 7.5 downstream of the borehole. Under intermediate flow conditions, the improvement in pH is most marked and values increase from around 5 to around 6.3. For acid sensitive "hard rock" areas such as those studied here, the bedrock has frequently been assumed to be both impermeable and low in base cations. This study illustrates that this view may be incorrect, and that groundwater may provide an important modifier of streamwater quality, at least for slate and shale dominated hard rock areas. Indeed, the work demonstrates clearly the potential for water quality remediation through groundwater manipulation.

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Classification and Prediction of Fecal Coliform in Stream Waters Using Decision Trees (DTs) for Upper Green River Watershed, Kentucky, USA

Water ◽

10.3390/w13192790 ◽

2021 ◽

Vol 13 (19) ◽

pp. 2790

Author(s):

Abdul Hannan ◽

Jagadeesh Anmala

Keyword(s):

Water Quality ◽

Random Forest ◽

Decision Tree ◽

Stream Water ◽

Fecal Coliforms ◽

Stream Water Quality ◽

Green River ◽

Input Variables ◽

Stream Waters

The classification of stream waters using parameters such as fecal coliforms into the classes of body contact and recreation, fishing and boating, domestic utilization, and danger itself is a significant practical problem of water quality prediction worldwide. Various statistical and causal approaches are used routinely to solve the problem from a causal modeling perspective. However, a transparent process in the form of Decision Trees is used to shed more light on the structure of input variables such as climate and land use in predicting the stream water quality in the current paper. The Decision Tree algorithms such as classification and regression tree (CART), iterative dichotomiser (ID3), random forest (RF), and ensemble methods such as bagging and boosting are applied to predict and classify the unknown stream water quality behavior from the input variables. The variants of bagging and boosting have also been looked at for more effective modeling results. Although the Random Forest, Gradient Boosting, and Extremely Randomized Tree models have been found to yield consistent classification results, DTs with Adaptive Boosting and Bagging gave the best testing accuracies out of all the attempted modeling approaches for the classification of Fecal Coliforms in the Upper Green River watershed, Kentucky, USA. Separately, a discussion of the Decision Support System (DSS) that uses Decision Tree Classifier (DTC) is provided.

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The occurrence of groundwater in the Lower Palaeozoic rocks of upland Central Wales

Hydrology and Earth System Sciences ◽

10.5194/hess-1-3-1997 ◽

1997 ◽

Vol 1 (1) ◽

pp. 3-18 ◽

Cited By ~ 44

Author(s):

C. Neal ◽

A. J. Robson ◽

P. Shand ◽

W. M. Edmunds ◽

A. J. Dixon ◽

...

Keyword(s):

Water Quality ◽

Stream Water ◽

Groundwater Resources ◽

Shallow Groundwater ◽

Base Cations ◽

Water Levels ◽

Stream Water Quality ◽

Groundwater Environment ◽

Catchment Areas ◽

Lower Palaeozoic

Abstract. A series of boreholes of up to 50 m depth, drilled into Lower Palaeozoic mudstone, shale and greywacke bedrock in the headwater catchment areas of the River Severn at Plynlimon in Central Wales, shows an extensive chemically- and hydrologically-active shallow groundwater fracture flow system. Groundwater chemistry varies in space and time with lowest water levels and highest alkalinities occurring during the drier summer months. The groundwaters are enriched in base cations, silica, sulphate and alkalinity relative to surface waters indicating significant silicate weathering sources and sulphide oxidation. These sources provide important contributions to both stream water quality and flow. At one site, the introduction of a borehole near to the main river opened bedrock fractures which increased the amount of groundwater entering the river. This had a profound effect on the river water quality by increasing the pH, alkalinity and calcium concentrations. As well as pointing to the possibility of the wider availability of groundwater resources in upland areas, the results highlight (a) the potential value of groundwater as a acid neutralizing resource, (b) the importance of weathering processes and flow routing within the groundwater environment for stream water chemistry, (c) the potential for altering stream water quality by manipulation of groundwater routing and (d) the need to include groundwater characteristics in hydrochemical management models of surface water acidification.

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Mobilisation of N and P from Agricultural Land and its Impact on Stream Water Quality in Karst Hilly Areas, Southwestern China

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.295-298.2148 ◽

2013 ◽

Vol 295-298 ◽

pp. 2148-2151

Author(s):

Fang Liu ◽

Jian Zhu ◽

Hai Bo Luo ◽

Yuan Sheng Liu

Keyword(s):

Water Quality ◽

Surface Water ◽

Agricultural Land ◽

Stream Water ◽

Surface Water Quality ◽

Guizhou Province ◽

Agricultural Lands ◽

Stream Water Quality ◽

High Concentration ◽

Stream Waters

In order to evaluate the impacts of N and P mobility from agricultural soils on surface water quality, the dissolved N and P concentrations in the runoff, the drainage and stream waters nearby agricultural lands were investigated at the karst hilly regions in central Guizhou Province. The results shown that the concentrations of NO3−, NH4+ and PO43− in the runoff from upland soils were 9.8~22.1 mg L−1, 0.429~0.818 mg L−1 and 0.025~0.052 mg L−1, respectively, and higher concentrations of NO3− (14.5~25.3 mg L−1) in the drainage waters from paddy soils. In karst areas, the concentrations of NO3− in the stream waters nearby agricultural lands was 14.9~28.5 mg L−1, as indicated by high concentration of NO3− compared with the Grade III of Surface Water Quality Standard of China, suggesting a eutrophication problem for surface water nearby agricultural lands with intensive cultivation.

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