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991.
992.
This study addressed the identification and monitoring of pollution sources of terrestrial origin in rivers (domestic sewage and industrial effluents) and critical fluvial segments in highly polluted environments under tidal influence (mixing marine and continental sources) from Guanabara Bay Basin, Rio de Janeiro, Brazil. The mass balance of contaminants was determined in conditions of continuous flow (low tide) during dry season (lower dilution capability). The results allowed the evaluation of the potential of contaminant mass generation by the different river segments and the estimation of their natural and anthropogenic components. The water quality of Igua?ú and Sarapuí Rivers were evaluated for metals and biochemical oxygen demand. The method gave an excellent response, including the possibility of sources identification and contaminated river segments ranking. The approach also offers fast execution and data interpretation, being highly efficient.  相似文献   
993.
Long-term data on precipitation and runoff are essential to draw firm conclusions about the behavior and trends of hydrological catchments that may be influenced by land use and climate change. Here the longest continuous runoff records from small catchments (<1 km(2)) in Switzerland (and possibly worldwide) are reported. The history of the hydrological monitoring in the Sperbel- and Rappengraben (Emmental) is summarized, and inherent uncertainties in the data arising from the operation of the gauges are described. The runoff stations operated safely for more than 90% of the summer months when most of the major flood events occurred. Nevertheless, the absolute values of peak runoff during the largest flood events are subject to considerable uncertainty. The observed differences in average, base, and peak runoff can only partly be attributed to the substantial differences in forest coverage. This treasure trove of data can be used in various ways, exemplified here with an analysis of the generalized extreme value distributions of the two catchments. These distributions, and hence flood return periods, have varied greatly in the course of one century, influenced by the occurrence of single extreme events. The data will be made publicly available for the further analysis of the mechanisms governing the runoff behavior of small catchments, as well as for testing stochastic and deterministic models.  相似文献   
994.
The sensitivity of Heterocypris incongruens to selected heavy metal ions is discussed. Although the Ostracodtoxkit ${\textregistered}$ has been present on the market for a few years, data on its selectivity and sensitivity to toxicants is scarce; such data is indispensable when interpreting the results of sediment toxicity. The LC50 and EC50 results with the Ostracodtoxkit ${\textregistered}$ are compared with those obtained with other commercially available ??direct-contact?? tests (utilizing Hyalella azteca and Chironomus riparius) and microbiotests for assessing the toxicity of aqueous samples (Vibrio fischeri, Daphnia magna, and Selenastrum capricornatum). The sensitivity of H. incongruens to metal ions (Cd2?+?>?>Hg2?+?> Cu2?+?>Cr6?+?>Ni2?+???Mn7?+?>Zn2?+?>Pb2?+?>Li1?+?> Fe3?+?) was found to be similar to that of H. azteca and of C. riparius. The Ostracodtoxkit ${\textregistered}$ has shown itself to be an efficient and reliable element of test batteries for toxicity determination.  相似文献   
995.
Solar radiation data are required by solar engineers, architects, agriculturists, and hydrologists for many applications such as solar heating, cooking, drying, and interior illumination of buildings. In order to achieve this, numerous empirical models have been developed all over the world to predict solar radiation. The main objective of this study is to examine and compare 147 solar radiation models available in the literature for the prediction of monthly solar radiation at Ankara (Turkey) based on selected statistical measures such as percentage error, mean percentage error, root mean square error, mean bias error, and correlation coefficient. Our results showed that Ball et al. (Agron J 96:391?C397, 2004) model and Chen et al. (Energy Convers Manag 47:2859?C2866, 2006) model performed best in the estimation of solar radiation on a horizontal surface for Ankara.  相似文献   
996.
Dredging water reservoirs is necessary to maintain accumulation capacity and to prevent floodings. As a first step, the quality of the bed sediments in water reservoirs must be determined before dredging operations. In this study, sediment samples from 34 stations of three selected water reservoirs (Zemplinska Sirava, Velke Kozmalovce, and Ruzin) were collected to investigate concentrations, distributions, and hazards of polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs) and to predict their possible sources. Total PCB concentrations were in the range of 20.4 to 2,325?ng/g. The maximum concentrations of PCBs were found in sediments from Zemplinska Sirava, which is in the vicinity of a former manufacturer of PCBs. The composition of PCBs was characterized by tri- and hexa-CB congeners, indicating the influence of contamination from the use of specific Delor mixtures, formerly produced and massively used on the territory of Slovakia. The data showed that the highest total PAH concentrations were associated with the sediments from the Velke Kozmalovce, ranging from 7,910 to 29,538?ng/g. On the other hand, the lowest total PAH concentrations (84?C631?ng/g of dry weight) were found in the sediments of Zemplinska Sirava, an important recreational area in eastern Slovakia. The distribution of individual PAHs was similar among the three water reservoirs, and this, together with principal component analysis and diagnostic PAH ratios, suggests mainly pyrolytic contamination of the sediments. However, petrogenic inputs appear to be important in the Zemplinska Sirava sediments.  相似文献   
997.
In this work, the heavy metals cadmium and lead in Kepez harbor were studied with regard to the determination of the environmental pollution levels. Seawater samples of the Dardanelles (Canakkale Strait) were collected from the nearest station to Kepez harbor in July 2007. Then, the concentrations of these metals were determined after simple pretreatment of samples by the proposed inductively coupled plasma?Catomic emission spectrometry (ICP-AES) method. The analysis of a given sample is completed in about 15 min by the ICP-AES method, and the concentrations of Cd and Pb were found to be 73.80 mg L???1 (relative standard deviation [RSD], 1.07%) and 9.39 mg L???1 (RSD, 0.70%), respectively. The accuracy of the applied ICP technique was checked by recovery studies, and good recoveries were obtained. The pollution levels of Cd and Pb recorded in this study were compared with those in other studies to analyze the water sample in Kepez harbor.  相似文献   
998.
The study involves the Çe?me?CUrla Peninsula, where habitat fragmentation and loss, which threaten biological diversity, have become an urgent matter of concern in recent decades. The study area has been subjected to anthropogenic pressures and alterations due to ongoing and impending land uses. Therefore, ecological networks, as an appropriate way to deal with habitat fragmentation and loss and to improve ecological quality, were identified in the study area as one of the early attempts in the country to maintain its rich biodiversity. In this sense, core areas and ecological linkages as primary components of ecological networks were established on the basis of sustaining natural habitats. A GIS-based model was created to identify core areas and to facilitate the ecological connectivity. The modeling process for core areas and corridors combined 14 and 21 different variables, respectively. The variables were used as environmental inputs in the model, and all analyses were materialized in ArcGIS 9.2 using grid functions of image analysis and spatial analyst modules. As a result, six core areas and 36 corridor alternatives were materialized. Furthermore, some recommendations for the implementation and management of the proposed ecological networks were revealed and discussed.  相似文献   
999.
Noise mapping has been used as an instrument for assessment of environmental noise, helping to support decision making on urban planning. In Brazil, urban noise is not yet recognized as a major environmental problem by the government. Besides, cities that have databases to drive acoustic simulations, making use of advanced noise mapping systems, are rare. This study sought an alternative method of noise mapping through the use of geoprocessing, which is feasible for the Brazilian reality and for other developing countries. The area chosen for the study was the central zone of the city of Sorocaba, located in São Paulo State, Brazil. The proposed method was effective in the spatial evaluation of equivalent sound pressure level. The results showed an urban area with high noise levels that exceed the legal standard, posing a threat to the welfare of the population.  相似文献   
1000.
The investigation was carried out in 8-year-old Scots pine (Pinus sylvestris L.) and lodgepole pine (Pinus contorta var. latifolia Engelm.) plantations on post-mining area, Northeast Estonia. The aim of the study was to assess the suitability of lodgepole pine for restoration of degraded lands by comparing the growth, biomass, and nutrient concentration of studied species. The height growth of trees was greater in the Scots pine stand, but the tree aboveground biomass was slightly larger in the lodgepole pine stand. The aboveground biomass allocation to the compartments did not differ significantly between species. The vertical distribution of compartments showed that 43.2% of the Scots pine needles were located in the middle layer of the crown, while 58.5% of the lodgepole pine needles were in the lowest layer of the crown. The largest share of the shoots and stem of both species was allocated to the lowest layer of the crown. For both species, the highest NPK concentrations were found in the?needles and the lowest in the stems. On the basis of the present study results, it can be concluded that the early growth of Scots pine and lodgepole pine on oil shale post-mining landscapes is similar.  相似文献   
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