نتایج جستجو برای: river and lake
تعداد نتایج: 16861317 فیلتر نتایج به سال:
—We made estimates of annual production of stream trout in two Lake Superior tributaries in northeastern Minnesota in 1977-1978. The Caribou River (total alkalinity, 34 mg/L as CaCO3) drains pan of the north shore of Lake Superior in an igneous rock geology. The Blackhoof River (total alkalinity, 83 mg/L) drains glacial drift and lake clay at the western end of Lake Superior. Annual production ...
Cichlid fishes have evolved tremendous morphological and behavioral diversity in the waters of East Africa. Within each of the Great Lakes Tanganyika, Malawi, and Victoria, the phenomena of hybridization and retention of ancestral polymorphism explain allele sharing across species. Here, we explore the sharing of single nucleotide polymorphisms (SNPs) between the major East African cichlid asse...
Abstract River–lake transition zones have been identified as major drivers of phytoplankton growth. With climate change reducing the frequency complete lake overturns, it is expected that Rhône River, main tributary to Lake Geneva (France/Switzerland), will become source nutrients for euphotic zone. The river–lake zone was hence examined at mouth River with aim understanding complexities and co...
[1] Ammonium and amino acid fluxes were examined as indicators of N and microbial food web dynamics in southern Lake Michigan during spring. Either NH4 + or a mixture of N-labelled amino acids (both at 4 mM N final concentration) was added to Lake Michigan water. Net fluxes were measured over 24 h under natural light and dark conditions using deck-top incubators and compared to microbial food w...
Low oxygen isotope values (;216‰, relative to Peedee belemnite standard) obtained from microbial carbonates of the Green River Formation have been interpreted as evidence for snowmelt and high elevations surrounding this early Eocene lake basin. However, low values from microbial precipitates could also represent a diagenetic overprint. We investigate these alternate hypotheses by measuring the...
Based on geomorphic observations, we discuss lake-level fluctuations, alluvial deposition and river entrenchment in the Dead Sea–Wadi Araba area. The bulk of alluvium in the northern Wadi Araba was probably deposited before the Lisan period of lake transgression that started at about 70 kyears B.P. The lake reached a maximum elevation about 150 m below sea level (b.s.l.), possibly around 15 cal...
Mining and ore excavation can cause the acidification and heavy metal pollution of downstream water systems. It can be difficult to assess the load contributions from individual mining areas, which is commonly required for environmental impact assessments. In the current study, we quantified the net impact of the unmonitored mining activities in the Zaamar Goldfield (Mongolia) on heavy metal tr...
59 To study the possible impact on the Lake Malawi/Nyasa/Niassa water quality due to actions performed at the watershed level, 61 and WL Delft Hydraulics to integrate physical and biochemical processes models in the lake and its basin which affect lake and 62 river water quality. The purpose of the integration of different models was to provide a set of tools in order to analyze the impact 63 o...
Considering the complexity of hydrological processes, it seems that multivariate methods may enhance the accuracy of time series models and the results obtained from them by taking more influential factors into account. Indeed, the results of multivariate models can improve the results of description, modeling, and prediction of different parameters by involving other influential factors. In th...
Lake Constance is the third largest lake in Central Europe. The river Rhine, which passes the lake, imports a significant amount of mineralic particles. Their transport and sedimentation within the lake is of importance for a number of applications, for example ship traffic, pumping stations for extraction of drinking water, hydraulic engineering, fishery, and ecology. Only satellites offer a c...
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