Nitrogen and phosphorus concentrations from agricultural catchments—influence of spatial and temporal variables

Arheimer, Berit; Lidén, Rikard

doi:10.1016/s0022-1694(99)00177-8

Cited by 179 publications

(144 citation statements)

References 46 publications

Supporting

Mentioning

121

Contrasting

Unclassified

Order By: Relevance

“…Salinity and phosphate have their origin in soils due to the use of phosphate fertilizers in this region as well as high salt content. Arheimer and Swank (2000) and Hill (1981), in their studies, conclude that agricultural land use strongly influences stream phosphorous. The presence of coliform is due to discharge into the river via surface runoff of domestic waste and fertilizer (animal waste) used in agricultural activities.…”

Section: Lpsmentioning

confidence: 95%

Spatial water quality assessment of Langat River Basin (Malaysia) using environmetric techniques

Juahir

Zain

Yusoff

et al. 2010

Environ Monit Assess

285

196

View full text Add to dashboard Cite

This study investigates the spatial water quality pattern of seven stations located along the main Langat River. Environmetric methods, namely, the hierarchical agglomerative cluster analysis (HACA), the discriminant analysis (DA), the principal component analysis (PCA), and the factor analysis (FA), were used to study the spatial variations of the most significant water quality variables and to determine the origin of pollution sources. Twenty-three water quality parameters were initially selected and analyzed. Three spatial clusters were formed based on HACA. These clusters are designated as downstream of Langat river, middle stream of Langat river, and upstream of Langat River regions. Forward and backward stepwise DA managed to discriminate six and seven water quality variables, respectively, from the original 23 variables. PCA and FA (varimax functionality) were used to investigate the origin of each water quality variable due to land use activities based on the three clustered regions. Seven principal components (PCs) were obtained with 81% total variation for the high-pollution source (HPS) region, while six PCs with 71% and 79% total variances were obtained for the moderatepollution source (MPS) and low-pollution source (LPS) regions, respectively. The pollution sources for the HPS and MPS are of anthropogenic sources (industrial, municipal waste, and agricultural runoff). For the LPS region, the domestic and agricultural runoffs are the main sources of pollution. From this study, we can conclude that the application of environmetric methods can reveal meaningful information on the spatial variability of a large and complex river water quality data.

show abstract

Section: Lpsmentioning

confidence: 95%

Spatial water quality assessment of Langat River Basin (Malaysia) using environmetric techniques

Juahir

Zain

Yusoff

et al. 2010

Environ Monit Assess

285

196

View full text Add to dashboard Cite

show abstract

“…The controls on DON export by rivers are not as clear (Hedin et al 1995;Arheimer and Liden 2000;Lovett et al 2000;McHale et al 2000). The current study illustrates the need to understand both how much DON is exported by different land uses and how much of the DON is biologically available from each source/land use in order to predict the effects of N loading on ecosystem processes.…”

Section: Bioavailability Of Don By Source and Season-mentioning

confidence: 99%

Bioavailability of DON from natural and anthropogenic sources to estuarine plankton

Seitzinger

Sanders

Styles

2002

Limnology & Oceanography

303

188

View full text Add to dashboard Cite

Utilization of dissolved organic nitrogen (DON) from natural (forests) and anthropogenic (animal pastures, urban/ suburban storm water runoff) sources (three sites per source) by estuarine plankton communities was examined in spring, summer, and fall. The proportion of DON utilized ranged from 0 to 73%. Overall, urban/suburban storm water runoff had a higher proportion of bioavailable DON (59% Ϯ 11) compared to agricultural pastures (30% Ϯ 14) and forests (23% Ϯ 19). DON bioavailability varied seasonally; however, the seasonal pattern differed for the three sources. Bacterial production increased linearly with the amount of DON utilized across all sources and seasons; the rate of increase was approximately five times greater per micromole of N as DON used relative to dissolved inorganic N (DIN) used. Although phytoplankton production generally increased with DON addition, the increased production was not correlated with the amount of DON utilized, suggesting that a variable portion of dissolved organic matter (DOM)-N was directly or indirectly available to the phytoplankton. This indicates that phytoplankton production is not a good measure of the amount of bioavailable DON, and measurements of the amount of bioavailable DON based on bacterial responses alone might not reflect N available to phytoplankton. Preliminary seasonal budgets of bioavailable N (DIN plus bioavailable DON) as a function of land use suggest that ϳ80% of the total dissolved N (TDN) from urban/suburban runoff is bioavailable, whereas a lower proportion (20-60%) of TDN is bioavailable from forests and pastures. N budgets for aquatic ecosystems based on only DIN loading underestimate bioavailable N loading, whereas total N or TDN budgets overestimate bioavailable N inputs.

show abstract

“…The major sources of nutrients may be related with watershed characteristics (Jordan et al 1997), land-use patterns of intensive agricultural activities and population-dense urban (Arheimer & Liden 2000), and point sources of industrial complex and wastewater disposal plants (WDPs, Wang et al 2001). High-nutrient loadings and organic matter inputs may decrease the proportions of sensitive species (SS) and increase tolerant species (TS) (Frey et al 2011).…”

Section: Introductionmentioning

confidence: 99%

Modifications of ecological trophic structures on chemical gradients in lotic ecosystems and their relations to stream ecosystem health

Ji-Woong

Lee

2013

Animal Cells and Systems

View full text Add to dashboard Cite

The objectives of this study were to evaluate how chemical gradients and physical habitats influence trophic dynamics and chemical tolerance in relation to ecological health, based on biological integrity model in the absence of cascading pressures (cascading theory) as a control mechanism of aquatic ecosystems. We conducted physical, chemical, and biological surveys from 76 national streams and rivers of four major watersheds during 2004Á2005 along with surveys of 80 reference streams. Maximum species richness lines (MSRLs) in reference sites vs. regular sampling sites indicated that the third-to fifth-order streams were evidently impaired in the metrics of trophic and tolerant components. These trophic modifications were linked with land-use patterns, which resulted in differences of nutrients (N, P), organic matter contents and the N:P ratios on trophic structures. Overall, these trophic factors influenced ecological health, based on multimetric index of biological integrity model in these systems, so that trophic compositions and tolerance were regulated by bottom-up hypothesis.

show abstract

Nitrogen and phosphorus concentrations from agricultural catchments—influence of spatial and temporal variables

Cited by 179 publications

References 46 publications

Spatial water quality assessment of Langat River Basin (Malaysia) using environmetric techniques

Spatial water quality assessment of Langat River Basin (Malaysia) using environmetric techniques

Bioavailability of DON from natural and anthropogenic sources to estuarine plankton

Modifications of ecological trophic structures on chemical gradients in lotic ecosystems and their relations to stream ecosystem health

Contact Info

Product

Resources

About