Flow management to sustain groundwater-dominated stream ecosystems

Petts, Geoffrey E.; Bickerton, Melanie A.; Crawford, Cliff; Lerner, David N.; Evans, David G.

doi:10.1002/(sici)1099-1085(19990228)13:3<497::aid-hyp753>3.0.co;2-s

Cited by 54 publications

(38 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…10), where only 29% of the best fitting models include the IRF (Table 1) and only 12% of the GWL variation is explained by the model. Sites in this cluster, like those in CL7, are widely dispersed and are interpreted as being due to long-term or historic over abstraction from the Chalk, for example as previously documented in Lincolnshire (Whitehead and Lawrence, 2006) and Cambridgeshire (Petts et al, 1999;Acreman et al, 2000) (Fig. 9c).…”

Section: Cluster Analysis Of Sgi Time Seriesmentioning

confidence: 59%

Spatio-temporal modelling of the status of groundwater droughts

Marchant

Bloomfield

2018

Journal of Hydrology

View full text Add to dashboard Cite

An empirical (geo)statistical modelling scheme is developed to address the challenges of modelling the severity and distribution of groundwater droughts given their spatially and temporally heterogeneous nature and given typically highly irregular groundwater level observations in space and time. The scheme is tested using GWL measurements from 948 observation boreholes across the Chalk aquifer (UK) to estimate monthly groundwater drought status from 1960 to 2013. For each borehole, monthly GWLs are simulated using empirical mixed models where the fixed effects are based on applying an impulse response function to the local monthly precipitation. Modelled GWLs are standardised using the Standardised Groundwater Index (SGI) and the monthly SGI values interpolated across the aquifer to produce spatially distributed monthly maps of SGI drought status for 54 years for the Chalk. The mixed models include fewer parameters than comparable lumped parameter groundwater models while explaining a similar proportion (more than 65%) of GWL variation. In addition, the empirical modelling approach enables confidence bounds on the predicted GWLs and SGI values to be estimated without the need for prior information about catchment or aquifer parameters. The results of the modelling scheme are illustrated for three major episodes of multi-annual drought (1975-1976; 1988-1992; 2011-2012). They agree with previous documented analyses of the groundwater droughts while providing for the first time a systematic, spatially coherent characterisation of the events. The scheme is amenable to use in near real time to provide short term forecasts of groundwater drought status if suitable forecasts of the driving meteorology are available.

show abstract

Section: Cluster Analysis Of Sgi Time Seriesmentioning

confidence: 59%

Spatio-temporal modelling of the status of groundwater droughts

Marchant

Bloomfield

2018

Journal of Hydrology

View full text Add to dashboard Cite

show abstract

“…For example, in the UK, the groundwater dominance of many rivers is expressed in terms of the base-flow index, with chalk streams and limestone streams having scores ranging from 0.5 to 0.99, whereas values in clay-bed streams or those with impermeable lithologies range from 0.14 to 0.45 (Newson 1994;Sear et al 1999). Regional assessments of the geomorphology, water quality and ecology of rivers with high base-flow indexes in the UK have revealed sufficient associations to indicate that these groundwater-dominated rivers are distinctive ecosystems and worthy of special management (Sear et al 1999;Petts et al 1999).…”

Section: Catchment-and Regional-scale Dependencymentioning

confidence: 99%

Rivers as groundwater-dependent ecosystems: a review of degrees of dependency, riverine processes and management implications

2006

View full text Add to dashboard Cite

Many rivers are classified as groundwater-dependent ecosystems (GDEs), owing to the contribution of groundwater to their base flow. However, there has been little explicit recognition of the way groundwater influences riverine biota or processes, how degrees of ecological dependency may vary, and the management implications of this dependency. The permeable beds and banks of these GDEs where surface water and groundwater exchange are termed 'hyporheic zones'. They are often inhabited by invertebrates, with varying reliance on groundwater, although the ecological roles of these invertebrates are little known. Upwelling hyporheic water can promote surface primary productivity, influence sediment microbial activity, and affect organic matter decomposition. In many intermittent streams, variable groundwater inputs alter the duration of flow or water permanence, and the duration and timing of these largely govern the biota and rates of many ecosystem processes (e.g. leaf decomposition). Not only is the physical presence of water important, thermal and chemical conditions arising from groundwater inputs also have direct and indirect effects on riverine biota and rates or types of in-stream processes. Differing degrees of dependency of rivers on groundwater mediate all these influences, and may change over time and in response to human activities. Alteration of groundwater inputs through extraction from riparian wells or changes in local water table have an impact on these GDEs, and some current management plans aim to restrict groundwater extraction from near permeable river channels. However, these are often 'blanket' restrictions and the mechanisms of GDE dependency or timing of groundwater requirements are poorly understood, hampering refinement of this management approach. More effective management of these GDEs into the future can result only from a better understanding of the mechanisms of the dependency, how these vary among river types and what in-stream changes might be predicted from alteration of groundwater inputs.

show abstract

“…This metric specifies a portion of surface water flow necessary to sustain desired environmental conditions during low flow periods, using August as an index proxy month for these calculations. This metric was developed as a ratio of streamflow to water withdrawal during the driest time of year (Petts et al 1999), which is also the time of year when human demand for water is highest -typically the month of August. Based on prior assessments, the metric specified that a 50% (i.e., a ratio equal to 0.5) instream flow was the minimum threshold to maintain aquatic health (Hamilton and Seelbach 2010).…”

Section: Great Lakes Energy-water Modelmentioning

confidence: 99%

The Water-Energy-Environment Nexus in the Great Lakes Region: The Case for Integrated Resource Planning

Tidwell¹,

Pebbles²

2015

EER

View full text Add to dashboard Cite

Water is a critical element of electric power production in the U.S., particularly in the Great Lakes Basin region. Thermoelectric power generation accounts for the majority of all water withdrawals in the Basin, in large part due to the comparatively heavy concentrations of coal and nuclear power generation that utilize open-loop cooling. This paper explores how different energy generation portfolios could affect the water resources of the Great Lakes Basin. The suite of power generation scenarios analyzed reflects a range of potential outcomes resulting from the implementation of key national and regional energy and environmental policies for the electric power industry. These policies include U.S. EPA's pending power plant cooling water intake standards, state renewable energy portfolio standards, possible climate change legislation, and the 2005 Great Lakes regional water resource agreement (Great Lakes and St. Lawrence River Basin Water Resources Compact of 2005; Public Law 110-342). Five scenarios were analyzed, resulting in different levels and intensities of total water use (withdrawal and consumption) in hydrologically-sensitive watersheds. These results confirm the close relationship between water and energy in the Great Lakes, and point to the need to take into account water resource impacts in designing future energy and environmental policies.

show abstract

Flow management to sustain groundwater-dominated stream ecosystems

Cited by 54 publications

References 17 publications

Spatio-temporal modelling of the status of groundwater droughts

Spatio-temporal modelling of the status of groundwater droughts

Rivers as groundwater-dependent ecosystems: a review of degrees of dependency, riverine processes and management implications

The Water-Energy-Environment Nexus in the Great Lakes Region: The Case for Integrated Resource Planning

Contact Info

Product

Resources

About