نتایج جستجو برای: catchments these sub

تعداد نتایج: 3233704  

2014
Dominika Saniewska Magdalena Bełdowska Jacek Bełdowski Michał Saniewski Marta Szubska Andrzej Romanowski Lucyna Falkowska

In Mediterranean seas and coastal zones, rivers can be the main source of mercury (Hg). Catchment management therefore affects the load of Hg reaching the sea with surface runoff. The major freshwater inflows to the Baltic Sea consist of large rivers. However, their systems are complex and identification of factors affecting the outflow of Hg from its catchments is difficult. For this reason, a...

2013
A Argerich S L Johnson S D Sebestyen C C Rhoades E Greathouse J D Knoepp M B Adams G E Likens J L Campbell W H McDowell F N Scatena

To examine whether stream nitrogen concentrations in forested reference catchments have changed over time and if patterns were consistent across the USA, we synthesized up to 44 yr of data collected from 22 catchments at seven USDA Forest Service Experimental Forests. Trends in stream nitrogen presented high spatial variability both among catchments at a site and among sites across the USA. We ...

2003
Carl Stapleton Brian Sanders David Kay Steven Anthony Hester Lyons Joseph Wilson Jon Greaves Ian Dunhill Peter Miles Andrew Wither

The virtual elimination of the principal point sources of human bacterial pollution through advanced treatment systems has not produced 100% compliance with microbial standards at all UK bathing water locations where they have been installed. This is partly explained by the existence of diffuse bacterial pollution derived from agricultural activities within catchments draining to the bathing zo...

2016
Guillaume G. Chevalier

Geomorphometry of headwater catchments has been poorly reported in the Central-Eastern Pyrenees. This study presents a series of parameters obtained for Central-Eastern Pyrenean headwater catchments. The database consists of 3005 1and 655 2-order catchments. These catchments have been digitalised, identified, and attributed a value for each parameter. The parameters investigated are divided int...

Journal: :Environmental pollution 2008
Z Gagkas K V Heal N Stuart T R Nisbet

Streamwater was sampled at high flows from 14 catchments with different (0-78%) percentages of broadleaf woodland cover in acid-sensitive areas in the UK to investigate whether woodland cover affects streamwater acidification. Significant positive correlations were found between broadleaf woodland cover and streamwater NO3 and Al concentrations. Streamwater NO3 concentrations exceeded non-marin...

2004
R. A. SPONSELLER E. F. BENFIELD

1. The structure of lotic macroinvertebrate communities may be strongly influenced by land-use practices within catchments. However, the relative magnitude of influence on the benthos may depend upon the spatial arrangement of different land uses in the catchment. 2. We examined the influence of land-cover patterns on in-stream physico-chemical features and macroinvertebrate assemblages in nine...

2017
Lorenzo Rovelli Karl M Attard Andrew Binley Catherine M Heppell Henrik Stahl Mark Trimmer Ronnie N Glud

We investigated the seasonal dynamics of in-stream metabolism at the reach scale (∼ 150 m) of headwaters across contrasting geological sub-catchments: clay, Greensand, and Chalk of the upper River Avon (UK). Benthic metabolic activity was quantified by aquatic eddy co-variance while water column activity was assessed by bottle incubations. Seasonal dynamics across reaches were specific for the ...

Journal: :Sustainability 2021

There has been renewed interest in the performance, functionality, and sustainability of traditional small-scale storage interventions (check dams, farm bunds tanks) used within semi-arid regions for improvement local water security landscape preservation. The Central Groundwater Board India is encouraging construction such alleviation scarcity to improve groundwater recharge. It important reso...

2016
Rita Ley Hugo Hellebrand Markus C. Casper Fabrizio Fenicia

This study investigates how the performance of a set of models depends on the catchments to which these models are applied. It examines (i) whether it is possible to identify a single best model for each of the catchments, or whether results are dominated by equifinality; and (ii) whether the ranking of model performance can be related to a set of predictors, such as climate and catchment chara...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه شهید چمران اهواز - دانشکده ادبیات و علوم انسانی 1389

this study purported to compare and contrast the use of self-mention and evidentials as two mtadiscourse features in opinion columns of persian and english newspapers. the theoretical basis of this study is the idea that metadiscourse features vary across cultural boundaries. for this purpose, 150 persian and 150 english opinion columns were collected based on three factors of topic, audience a...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید