206 research outputs found
Technology evaluation of heating, ventilation, and air conditioning for MIUS application
Potential ways of providing heating, ventilation, and air conditioning for a building complex serviced by a modular integrated utility system (MIUS) are examined. Literature surveys were conducted to investigate both conventional and unusual systems to serve this purpose. The advantages and disadvantages of the systems most compatible with MIUS are discussed
Thirty four Galloway Lochs: bathymetry, water quality and surface sediment diatom assemblages
Bathymetric descriptions of thirty four Galloway lochs are
given together with water quality data for 1983-85. Results of diatom analysis of surface sediment collected
from each loch are presented in tabular form. Lake water pH is generally lower in November samples than in samples collected in summer months. Cation exchange, following deposition of sea salts on peaty catchments, is suggested as a partial
winter period. cause of pH depression in the winter period. Where lakes are deep enough, summer thermal stratification
usually occurs between 5 and 8 m depth. Floristic diversity of the periphyton component of surface
sediment diatom assemblages is shown to increase generally
with pH
Lake sediment toxicity in the UK: the role of trace metals and persistent organic pollutants
The aim of this project was to determine sediment toxicities to the sediment-dwelling chironomid
Chironomus riparius and the free-swimming cladoceran Daphnia magna using empirical
measurements from ten lakes distributed both geographically across the UK and across a predicted
toxicity quotient gradient
Evaluating macrophytes as indicators of anthropogenic pressures in rivers in Ireland
Publication history: Accepted - 6 January 2021; Published online - 10 February 2021.The ability of macrophytes to indicate
pressures in rivers was assessed by comparing metrics
for nitrate (NO3), ammonia (NH4), soluble reactive
phosphorus (SRP), dissolved oxygen saturation (DO),
pH (PH) and siltation (SUBS) with direct estimates of
the pressures at 810 sites in the Republic of Ireland,
supplemented with General Linear Models (GLMs).
The bivariate and rank correlation coefficients using
the full data range and the first and fourth quartiles of
the river pressures varied between 0.22 and - 0.39 for
NO3 and DO; they were smaller or not significant for
the other four metrics. The GLMs provided evidence
for an independent association between NO3 and the
nitrate concentration and SUBS and ammonia,
indicating some specificity for these metrics. Discriminating
sites in the first and fourth quartiles produced
Type II errors between 37 (PH) and 69% (NH4), with a
mean of 50. As the pressure-impact relationships are
not precise enough (low correlation coefficients) that
evidence from a single macrophyte metric is reliable,
combining the metric with evidence from other
biological groups at one site or from three or more
sites may be the most useful approach.Environmental Protection Agency of Ireland - funding of the DETECT Project
(2015-W-LS-9)
Burnley Borough Council - funding to AB
The long-term response of lake nutrient and chlorophyll concentrations to changes in nutrient loading in Ireland's largest lake, Lough Neagh
The long-term response of chlorophyll-a (chl-a) to changing lake water nutrient concentrations and increasing water temperature was investigated in Lough Neagh, a large, hypereutrophic lake in Northern Ireland. Trends in external and internal nutrient loading and their relation to lake nutrient concentrations were also established. Lake water concentrations of total P (TP) have increased since the 1990s but were not correlated with catchment inputs, which showed no trend. The characteristics of internal loading of P have changed since the mid-1990s, with an earlier and larger mass of P released from the sediments each summer. Catchment inputs of total oxidised N (NOx) decreased from the peak value of 10,186T/yr in 1995 to 5,396T/yr in 2011, coinciding with a reduction in lake water concentrations. External inputs and lake concentrations of NOx were highly correlated (R=0.88). Water temperature increased approximately 1C and was a predictor of variation in chl-a from 1974 to 2012. After the peak chl-a concentration in 1993, dissolved inorganic N (DIN) also became an important predictor, accounting for almost half of the 44% variance explained by a hierarchical partition model. Decreasing log (DIN:TP) ratios suggest that N limitation of chl-a has become more important in the lake recently
Acidification in the Cairngorms and Lochnagar: a palaeoecological assessment
Sensitive lakes in areas of the United Kingdom with moderate to high sulphur
deposition have been acidified since the middle of the nineteenth century- (Battarbee et al.
1988). Regions such as Galloway, south west Scotland (eg. Flower and Battarbee 1983,
Flower et al. 1987), Wales (eg. Battarbee et al. 1988, Fritz et aL 1990), Cumbria (eg.
Battarbee et al 1988, Atkinson and Haworth 1990), and Rannoch Moor in the central
Scottish Highlands (eg. Flower et al 1988) have been affected. This study extends the
geographical survey of lake acidification to the Caimgorm and Lochnagar regions of north
east Scotland (Figure 1). The Caimgorms and Lochnagar are areas of considerable
conservation value, forming the largest single area of land over 1000 m in the UK. The
Caimgorm mountain plateau is a National Nature Reserve, noted for its alpine flora and
fauna, whilst the Lochnagar range is a Scottish Wildlife Trust reserve.
A secondary- aim of the study was to evaluate the 11land-use 11 hypothesis (eg.
Rosenqvist 1977, 1978, 1981) as a mechanism for lake acidification by examining high
altitude sites with no active land-management. Sites selected are all remote, lie above the
tree line and have undisturbed catchments.
Lochnagar and the Caimgorms are situated on sensitive granite geology (Kinniburgh
and Edmunds 1986, Wells et al. 1986) in an area of moderate acid deposition (c. 0.95 g S
yr-1
). It can be predicted that sensitive lakes in this area (those having Ca2
+ values of <60
μeq i-1
) will have acidified (Battarbee 1989)
Palaeoecological evaluation of the recent acidification of Lochnagar, Scotland
Lochnagar, a high altitude, relatively deep, come lake, lies on the Royal Deeside ESUHC of
Balmoral, in an area which experiences moderate levels of acid deposition, The loch catchment
comprises granite bedrock and is dominated by bare rock but overlain in places with blanket peals,
Lochnagar may thus be considered potentially susceptible to acidification, The contemporary pH of
the loch water is c. 5,0
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