Environmental Science and Pollution Research - Mercury (Hg) is a great concern for marine environments. Bird feathers have been widely used to assess Hg pollution. In this study, we determine... 相似文献
The sigma (SIG) coordinate system in ocean circulation simulation models results inevitably in horizontal pressure gradient error. This problem also emerges in models of deep lakes or reservoirs with the same characteristics of underwater terrain mutation. SIG coordinates reflect vertical relative stratification but cannot be used to calculate horizontal pressure gradient force in places with drastic topographic changes; this results in vertical water temperature and circulation errors. In deep lakes or reservoirs, differences in water density caused by the temperature difference between upper and lower water bodies is the primary cause of thermal stratification phenomena. Lake Mead was used as a case study on steep topography based on Environmental Fluid Dynamics Code (EFDC) model in this study. SIG coordinates result in close agreement between the calibrated temperature time series at the top and middle water layers, but disparity in the bottom water layer. The error emerges in the horizontal pressure gradient error due to the SIG coordinate transformation. Neither increasing the vertical resolution nor adjusting the horizontal viscosity coefficient resolve this error. We test the sigma-zed (SGZ) coordinate which combines Z coordinate and SIG coordinate as a replacement for the SIG coordinate to find that they effectively reduce the model’s runtime and simulation efficiency. The vertical temperature distribution in SGZ coordinate mode is more accurate than the distribution in SIG coordinate mode. The Navier-Stokes horizontal gradient and advection diffusion equation results under SIG coordinates are very sensitive to the pressure gradient. The replacement also enhances resolution near the thermocline, facilitates reclosing of the water bottom and the equal sigma surface, lends significant advantages in terms of vertical temperature in the simulation for local deep water with steep terrain, and shortens runtime for 0.14 h. SGZ mixed coordinates are recommended in the simulation of deep lakes or reservoirs wherein the underwater topography is large (with abundant continuous deep trenches or reefs).
Environmental Science and Pollution Research - Slope failure is a one of major process that causes severe landform variation and environment variation, and slope failure has become a major hidden... 相似文献
Environmental Science and Pollution Research - Bio-waste materials from aquatic species are alternative sources of chitin and chitosan—high-value natural biodegradable and biocompatible... 相似文献
Environmental Science and Pollution Research - Magnetic nanostructured MnFe2O4 with different morphologies, synthesized via chemical co-precipitation and hydrothermal method, was assayed as... 相似文献
Environmental Science and Pollution Research - A linear algebra theorem like Cramer’s rule was used for the analysis of a system of equations obtained from UV spectroscopy, and results were... 相似文献
Environmental Science and Pollution Research - The accurate prediction of daily reference crop evapotranspiration (ETO) enables effective management decision-making for agricultural water... 相似文献
Environmental Science and Pollution Research - Runoff forecasting is essential for the reasonable use of regional water resources, flood prevention, and mitigation, as well as the development of... 相似文献
Pharmaceuticals are emerging pollutants widely used in everyday urban activities which can be detected in surface, ground,
and drinking waters. Their presence is derived from consumption of medicines, disposal of expired medications, release of
treated and untreated urban effluents, and from the pharmaceutical industry. Their growing use has become an alarming environmental
problem which potentially will become dangerous in the future. However, there is still a lack of knowledge about long-term
effects in non-target organisms as well as for human health. Toxicity testing has indicated a relatively low acute toxicity
to fish species, but no information is available on possible sublethal effects. This study provides data on the physiological
pathways involved in the exposure of Atlantic salmon as representative test species to three pharmaceutical compounds found
in ground, surface, and drinking waters based on the evaluation of the xenobiotic-induced impairment resulting in the activation
and silencing of specific genes. 相似文献
A set of toxic metals, i.e. As, Hg, Pb, Cd, Cu, Zn, Ni and Cr, in urban and suburban SDSs were investigated comparatively in the biggest metropolitan area of China, Shanghai. Results showed that all of the metals except As were accumulated greatly, much higher than background values. Geo-accumulation index indicated that metal contamination in urban SDSs was generally heavier than that in suburban SDSs. Potential ecological risk index demonstrated that overall risks caused by metals were considerable. Cd contributed 52% to the overall risk. Multivariate statistical analysis revealed that in urban SDSs, Zn, Ni, Cd, Pb, Cu and Cr were related to traffic and industry; coal combustion led to elevated levels of Hg; soil parent materials controlled As contents. In suburban SDSs, Pb, Cu, As and Cd largely originated from traffic pollution; Zn, Ni and Cr were associated with industrial contaminants; Hg was mainly from domestic solid waste. 相似文献