Soluble nitrogen and phosphorus in the River Ythan system, U.K.: Annual and seasonal trends

MacDonald, Alan; Edwards, Anthony C.; Pugh, K.B.; Balls, P.W.

doi:10.1016/0043-1354(94)00210-x

Cited by 45 publications

(25 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…03 kg ha 71 yr 71 ( Figure 2B), and are similar to those recorded in previous UK studies (e.g. Oborne et al, 1980;Webb and Walling, 1985;Johnes and Burt, 1991;MacDonald et al, 1995). TN¯ux was 11±19 times higher than TP transport in the study rivers.…”

Section: Annual Nutrient Loadssupporting

confidence: 88%

See 1 more Smart Citation

The composition of nutrient fluxes from contrasting UK river basins

et al. 1998

View full text Add to dashboard Cite

Abstract:Accurate estimates of N and P loads were obtained for four contrasting UK river basins over a complete annual cycle. The fractionation of these loads into dissolved and particulate, and inorganic and organic components allowed a detailed examination of the nutrient load composition and of the factors in¯uencing both the relative and absolute magnitude of these components. The particulate phosphorus (TPP) loads account for 26±75% of the annual total phosphorus (TP) transport and are predominantly inorganic. The inorganic (PIP) and organic (POP) fractions of the TPP loads represent 20±47% and 6±28% of the annual TP transport, respectively. In contrast, the particulate nitrogen loads (TPN) represent 8% or less of the annual total nitrogen (TN) loads and are predominately organic. For dissolved P transport, the dissolved inorganic fraction (DIP) is more important, representing 15±70% of the TP loads, whereas the dissolved organic fraction (DOP) represents only 3±9% of the TP loads. The TN loads are dominated by the dissolved component and more particularly the total oxidized fraction (TON), which is composed of nitrate and nitrite and represents 76±82% of the annual TN transport. The remaining dissolved N species, ammonium (NH 4 -N) and organic N (DON) account for 0 . 3±1 . 2% and 13±16% of the annual TN transport, respectively. The TPN and TPP¯uxes closely re¯ect the suspended sediment dynamics of the study basins, which are in turn controlled by basin size and morphology. The dissolved inorganic nutrient¯uxes are in¯uenced by point source inputs to the study basins, especially for P, although the TON¯ux is primarily in¯uenced by diuse source contributions and the hydrological connectivity between the river and its catchment area. The dissolved organic fractions are closely related to the dissolved organic carbon (DOC) dynamics, which are in turn in¯uenced by land use and basin size. The magnitude of the NH 4 -N fraction was dependent on the proximity of the monitoring station to point source discharges, because of rapid nitri®cation within the water column. However, during storm events, desorption from suspended sediment may be temporarily important. Both the magnitude and relative contribution of the dierent nutrient fractions exhibit signi®cant seasonal variability in response to the hydrological regime, sediment mobilization, the degree of dilution of point source inputs and biological processes. #

show abstract

Section: Annual Nutrient Loadssupporting

confidence: 88%

“…Edwards, 1973;Oborne et al, 1980) and at quantifying the annual nutrient loads of rivers and streams (e.g. MacDonald et al, 1995;Muscutt and Withers, 1996). These studies have often considered only the dissolved inorganic forms (e.g.…”

Section: Introductionmentioning

confidence: 98%

The composition of nutrient fluxes from contrasting UK river basins

et al. 1998

View full text Add to dashboard Cite

show abstract

“…In previous studies analyzing long-term trends regarding water quality and/or pollutant load in rivers, it has been reported that the progress of wastewater treatments effectively reduced the nitrogen and phosphorus concentrations in rivers (Lehmann and Rode, 2001;Parr and Mason, 2003;Pastres et al, 2004), while the expansion of agricultural practices caused the levels of these components to increase (Macdonald et al, 1995;Fig. 6 -Box plot of three data sets of precipitation and the concentrations of various water quality parameters.…”

Section: Discussionmentioning

confidence: 99%

Long-term trends in water quality in an under-populated watershed and influence of precipitation

Takeda

Fukushima

Somura

2009

J. of Wat. & Envir. Tech.

View full text Add to dashboard Cite

An investigation of the water quality in an under-populated watershed was conducted over a 15-year period in which data was collected at weekly intervals. The purposes of this study were to analyze the long-term trends in water quality and to evaluate the relationship between the water quality and precipitation. Concentrations of total phosphorus (T-P), chemical oxygen demand (COD), and suspended solids (SS) reached remarkably high values under heavy precipitation conditions, and these concentrations increased exponentially with the amount of precipitation. Over the course of this study, the population, number of factories, animals (cow and pig), and area of agricultural land exhibited clearly decreasing trends, while steady progress in domestic wastewater treatment was realized. However, no clear decrease in the parameters of water quality was observed, and some nitrogen, phosphorus, and COD concentrations increased even though no significant change in precipitation occurred. A possible hypothesis explaining this lack of a clear decrease in water quality is that specific pollutant outflows from forests and agricultural lands may have increased in recent years. This is because poorly managed forests and agricultural lands in the under-populated watershed have adversely affected the water quality of the rivers.

show abstract

“…Total N and P concentrations in the River Ythan 8 and its estuary 9 have shown an increase over recent decades, associated with changes in agricultural practice in the area. 8,10 The catchment has therefore been the subject of investigations under the EC Nitrate Directive.…”

Section: Introductionmentioning

confidence: 99%