DRASTIC-Fm: a modified vulnerability mapping method for structurally controlled aquifers in the southern Gulf Islands, British Columbia, Canada

Denny, S; Allen, D. M.; Journeay, J M

doi:10.1007/s10040-006-0102-8

Cited by 117 publications

(48 citation statements)

References 9 publications

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“…Groundwater vulnerability to contamination was evalu-ated using several methods: GOD-S (Foster 1987;Foster and Hirata 1988;Foster et al 2002), Pesticide DRASTIC-Fm (Aller et al 1987;Denny et al 2007), SINTACS (Civita 1994(Civita , 2010Civita and De Maio 2000) and SI (Ribeiro 2000;France´s et al 2001). For DRASTIC-Fm, two updates were done: (1) the assigned weights for DRASTIC were those proposed for Pesticide DRASTIC; (2) the Fm parameter was derived from the tectonic lineaments density map and grouped into five classes (km of lineaments/km 2 ): \4, 4-8, 8-12, 12-16 and [16, with ratings of 2, 4, 6, 8 and 10, respectively.…”

Section: Methodsmentioning

confidence: 99%

Assessment of groundwater contamination in an agricultural peri-urban area (NW Portugal): an integrated approach

et al. 2014

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The excessive use of pesticides and fertilisers in agriculture has generated a decrease in groundwater and surface water quality in many regions of the EU, consti-tuting a hazard for human health and the environment. Besides, on-site sewage disposal is an important source of groundwater contamination in urban and peri-urban areas. The assessment of groundwater vulnerability to contami-nation is an important tool to fulfil the demands of EU Directives. The purpose of this study is to assess the groundwater vulnerability to contamination related mainly to agricultural activities in a peri-urban area (Vila do Conde, NW Portugal). The hydrogeological framework is characterised mainly by fissured granitic basement and sedimentary cover. Water samples were collected and analysed for temperature, pH, electrical conductivity, chloride, phosphate, nitrate and nitrite. An evaluation of groundwater vulnerability to contamination was applied (GOD-S, Pesticide DRASTIC-Fm, SINTACS and SI) and the potential nitrate contamination risk was assessed, both on a hydrogeological GIS-based mapping. A principal component analysis was performed to characterised pat-terns of relationship among groundwater contamination, vulnerability, and the hydrogeological setting assessed. Levels of nitrate above legislation limits were detected in 75 % of the samples analysed. Alluvia units showed the highest nitrate concentrations and also the highest vulner-ability and risk. Nitrate contamination is a serious problem affecting groundwater, particularly shallow aquifers, especially due to agriculture activities, livestock and cesspools. GIS-based cartography provided an accurate way to improve knowledge on water circulation models and global functioning of local aquifer systems. Finally, this study highlights the adequacy of an integrated approach, combining hydrogeochemical data, vulnerability assessments and multivariate analysis, to understand groundwater processes in peri-urban areas.

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Section: Methodsmentioning

confidence: 99%

Assessment of groundwater contamination in an agricultural peri-urban area (NW Portugal): an integrated approach

et al. 2014

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“…Islands and the area as a whole (Foweraker, 1974;Hodge, 1977;Hodge, 1995;Liteanu, 2003;Allen and Liteanu, 2006;Trapp, 2011;Scibek et al, 2013;Appiah-Adjei, 2006;Denny et al, 2007;Larocque, 2014;Burgess, in progress) (Table 2.4). Estimates of mean recharge range from 2.6% to 56% of mean annual precipitation.…”

Section: Numerous Studies Have Attempted To Estimate Recharge On Indimentioning

confidence: 99%

Response of a fractured bedrock aquifer to recharge from heavy rainfall events

Rathay

Allen

Kirste

2018

Journal of Hydrology

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The response of a fractured bedrock aquifer in a temperate region (Gulf Islands, British Columbia) to heavy rainfall events is characterized. Of the 14 provincial observation wells with hourly groundwater level data, wells with shallow water levels showed pronounced responses to heavy rain events, a lag less than 12 hours, and a strong correlation to all rain events. Rises in groundwater level at Well 125 appear to be better related to all rain events than exclusively heavy rain during summer, and decrease as the rainfall intensity increases. Thermal infrared images and δ 18 O and δ 2 H composition for precipitation and seepage indicate an increase in seepage in the late fall and winter.Solution of the Green-Ampt equation for rainfall events of varying magnitude suggest that an increase in winter rainfall intensity leads to more surface ponding and overland flow. The projected occurrence of more heavy rain events in the future may result in lower net recharge.

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“…Specialized methods have been developed for use in areas with specific geological conditions, such as karst environments (Doerfliger et al 1999;Goldscheider et al 2000) and fractured bedrock (Denny et al 2007). Typically the methods involve creating a series of maps or overlays, often within a Geographic Information System (GIS), which define the various intrinsic properties of the aquifer.…”

Section: Aquifer Susceptibilitymentioning

confidence: 99%

“…In an attempt to overcome some of its limitations, for example, the presence of fractures in bedrock, modifications to DRASTIC have been made (Denny et al 2007 (Wei 1998), the Gulf Islands (Denny et al 2007), the Oliver and Vernon areas of the Okanagan (Liggett et al 2006;Liggett 2008), and Vancouver Island (Liggett and Gilchrist 2010).…”

Section: Drasticmentioning

confidence: 99%

“…Some of the more commonly used intrinsic susceptibility mapping methods include GOD (Foster 1987), AVI (Van Stempvoort et al 1993) and DRASTIC (Aller et al 1987). Specialized methods have been developed for use in areas where other methods are inadequate, such as in Karst environments (Doerfliger et al 1999;Goldscheider et al 2000) and fractured bedrock (Denny et al 2007). Input parameters often include soil properties, surficial geology, recharge rates, travel time through the vadose zone, aquifer hydraulic conductivity, depth to water, land use, topography, properties of confining beds, surface water connectivity, and/or aquifer thickness (Gogu and Dassargues 2000).…”

Section: Intrinsic Aquifer Susceptibilitymentioning

confidence: 99%

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Assessing risk to groundwater quality using an integrated risk framework

2013

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Risk to groundwater quality is defined as a function of susceptibility, hazard and consequence. Aquifer susceptibility combines the intrinsic susceptibility of the physical system with potential preferential pathways. Hazard threats are assessed based on the potential impact and probability of release. The consequence is the financial cost of the loss of the resource. The risk assessment methodology is applied to the Township of vi

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DRASTIC-Fm: a modified vulnerability mapping method for structurally controlled aquifers in the southern Gulf Islands, British Columbia, Canada

Cited by 117 publications

References 9 publications

Assessment of groundwater contamination in an agricultural peri-urban area (NW Portugal): an integrated approach

Assessment of groundwater contamination in an agricultural peri-urban area (NW Portugal): an integrated approach

Response of a fractured bedrock aquifer to recharge from heavy rainfall events

Assessing risk to groundwater quality using an integrated risk framework

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