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1.
The results of studies of spatial and seasonal variations in hydrocarbon concentrations in hypertrophic Lake Nero are used to discuss the problem of division of hydrocarbons into anthropogenic and natural components. It is shown that the use of bitumoids as a component of oil pollution instead of total organic matter can introduce errors in the results. Seasonal variations in the activity of hydrobionts in an undisturbed area are shown to have a notable effect on the assessment of the proportion of anthropogenic hydrocarbons in their total concentration, that is, on the assessment of the extent of pollution of water bodies. The natural component is found to dominate over the anthropogenic component only in the periods of algae blooming. In spring and autumn, the total concentration of hydrocarbons was found to exceed the MAC and to be due mostly to natural hydrobiological factors.  相似文献   

2.
Otyukova  N. G. 《Water Resources》2021,48(3):449-458
Water Resources - Indirect chemical characteristics of organic matter concentration were determined in small streams in especially protected natural territories, including 15 tributaries of Lake...  相似文献   

3.
武汉东湖水生植被的恢复试验研究   总被引:24,自引:4,他引:24  
本文报道了在武汉东湖所作的水生植被恢复的研究结果,分别在东湖水果湖、汤林湖和后湖等三个湖建立水生植被恢复示范区。  相似文献   

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An azimuthal resistivity survey was conducted at the transition zone between the desert area and the cultivated land near Lake Qaroun, Egypt. This area has been affected by an east-west trending fault system as indicated from the surface geology. Apparent resistivity values were plotted along azimuth on a polar diagram. Resistivity anomalies, for most of the AB/2 values with long axes strike in a direction parallel to the contact between the desert and cultivated lands, indicate the presence of electrical macro-anisotropy, mainly due to the faulting effect, at this area. Vertical electrical soundings (VES) and transient electromagnetic (TEM) measurements were conducted at eight stations along a line that crosses the boundary between the desert and cultivated land. Joint inversion of VES-TEM data was successfully used for identification of the subsurface lithostratigraphic succession and demonstrated the effect of the fault zone on the investigated subsurface medium. Apparent anisotropy coefficients at all current electrode spacings were calculated, plotted against AB/2 values and compared with the geoelectrical cross section. The effect of the fault zone was detected at AB/2 spacings equal to 100 m and extended downward and is largely related to the depth of the fault, as indicated in the constructed cross section.  相似文献   

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The optical properties and spatial distribution of chromophoric dissolved organic matter (CDOM) in Meiliang Bay of Lake Taihu were evaluated and compared to the results in literature. Concentrations of dissolved organic carbon (DOC) ranged from 8.75 to 20.19 mg L?1 with an average of (13.10 ± 3.51) mg L?1. CDOM absorption coefficients a(λ) at 280 nm, 355 nm, and 440 nm were in the range 11.28...33.46 m?1 (average (20.95 ± 5.52) m?1), 2.42...7.90 m?1 (average (4.92 ± 1.29) m?1), and 0.65...2.44 m?1 (average (1.46 ± 0.44) m?1), respectively. In general, CDOM absorption coefficient and DOC concentration were found to decrease away from the river inflow to Meiliang Bay towards the lake center. The values of the DOC‐specific absorption coefficients a*(λ), given as absorption coefficient related to mass concentration of organic carbon (C) ranged from 0.28 to 0.47 L mg?1 m?1 at 355 nm. The determination coefficients between CDOM absorption and DOC concentration decreased with the increase of wavelength from 280 to 550 nm. The linear regression relationship between CDOM absorption at 280 nm and DOC concentration was following: a(280 nm) = 1.507 L mg?1 m?1 · DOC + 1.215 m?1. The spectral slope S values were dependent on the wavelength range used in the regression. The estimated S values decreased with increasing wavelength range used. A significant negative linear relationship was found between CDOM absorption coefficients, DOC‐specific absorption coefficients and estimated S values especially in longer wavelength range. The linear regression relationship between DOC‐specific absorption coefficients at 440 nm and estimated S values during the wavelength range from 280 to 500 nm was following: a*(440 nm) = (–0.021 μm · S + 0.424) L mg?1 m?1.  相似文献   

8.
Lukin  A. A.  Sharova  Yu. N. 《Water Resources》2004,31(4):443-449
Specific hydrological and hydrochemical conditions in Kenozero Lake have led to changes in the morphology of fishes at a cellular level. The abnormalities in the function of the respiratory, digestive, and excretory systems were recorded. The degree of pathology depended on the ecological features of the fish. The pathological changes were most pronounced in the gills of the fish species (orfe, perch, and roach) characterized by active mode of life and sensible to oxygen deficiency. The changes in the epithelium of gill filaments had a compensatory significance and were aimed at increasing the area of the functional surface of the gills under the conditions of hypoxia.  相似文献   

9.
The results of probabilistic analysis of data on setup level variations collected during long-term observations at all gages along the Caspian Sea coast are discussed. A procedure for evaluating low-probability sea level extremes is proposed. Estimates are given for the probabilities of outstanding setups in the Caspian Sea and the Sea of Azov.  相似文献   

10.
Water Resources - The objectives of this study were to predict the water quality index using Support Vector Machine (SVM) model and to identify the most important attributes affecting the...  相似文献   

11.
浙江瓯江开潭水库库区浮游植物与水质的关系   总被引:1,自引:0,他引:1  
朱圣潮  何爱兰 《湖泊科学》2003,15(4):353-358
通过2001年7月-2002年6月对瓯江开潭水库库区水体浮游植物的调查,以及对溶解氧和叶绿素a等理化指标的逐月测定,结果表明:该水域共有浮游植物7门40属82种(包括变种),其中以绿藻门和硅藻门的种类占优势,浮游植物的群落类型为绿藻型和硅藻型为主,种类和数量随季节和水域不同而呈现差异,水体营养特征为浮游植物响应型,水体向中营养化发展趋势明显,部分水体受到不同程度污染.  相似文献   

12.
A large number of ground water samples (360) was collected from 60 stations over six consecutive seasons to study the influence of the main sewerage drain on shallow ground water table beneath the municipal area of Cuttack, India. A majority of the samples collected from stations close to the drain exceeded the maximum permissible limits set by the World Health Organization (WHO). Almost all the samples near the drain exceeded the WHO limit for NO3- and Na+. However, the concentrations decreased as the distance from the drain increased. The winter season registered the maximum concentrations of NH4+, NO3-, and SO42- ions whereas the minimum values always coincided with the rainy season. R-mode factor analysis was conducted to find relationships amongst the 16 chemical parameters studied. Fluoride showed a negative correlation with Cl-, Na+, NO3-, SO42-, and PO43-. The concentration of F- may be lower in raw waste water than naturally occurs in the ground water. Therefore, a decrease in the concentration of F- near the drain may be attributed to dilution by contributions of waste water to the ground water. The rest of the parameters were found to be directly related to the distance of collection points to the sewerage. The distribution of nutrients is strongly affected by leaching of waste water into the ground water.  相似文献   

13.
The spatial and temporal distribution of humic substances in aquatic ecosystems can have important effects on ecosystem productivity, negatively impacting primary productivity while positively impacting secondary productivity. In the present investigation, a large shallow lake ecosystem was studied to determine the spatial and seasonal variation of the composition and concentration of humic substances. Concentrations of total dissolved organic matter, humic acid, and fulvic acid were found to display significant spatial distributions (1.3…13.5 mg/L, DOM; 0.1…5.4 mg/L, HA). The distribution is described by using mapping techniques and the analysis of the spatial distribution of the lake. An analysis of the seasonal variations also indicated the dependence of the occurrence of these compounds on meteorological and hydrological conditions. To identify the potential sources of these organic materials, an analysis was made of the ratio of humic and fulvic acid fractions and total DOM. It was found that areas of high DOM concentration coincided with the areas of highest HA percentage of total DOM. Furthermore using the ratio of the normalised concentrations of HA, FA, and residual DOM (< 5000 g/mol) it was found that areas dominated by each are spatially distinct. This confirms the hypothesis that in these shallow lakes, photodegradation and bacterioplankton activity will create a residence time dependent zonation of each component of the total DOM.  相似文献   

14.
2015年1月9日,云南地区出现大幅度水位同步转折上升现象,而地下流体群体异常的聚集区可能是未来强震的孕育区,及时排除环境等干扰因素,对确定地震危险区很有帮助。本文选取澄江井和建水井的水位观测数据,分析降雨量与水位变化的关系,认为滇南地区的水位年变化与雨季降雨量之间有较好的线性关系。本文对澄江井和建水井2012-2014年的水位异常信息进行提取,对其映震情况进行了总结,研究表明滇南地区降雨量对水位引起的异常,主要表现在变化幅度和变化时间等方面。此次出现的水位同步转折上升现象多为降雨干扰影响。  相似文献   

15.
For regulators to develop risk-based screening levels (RBSLs) for a petroleum constituent, a maximum allowable concentration at an exposure point, such as a drinking water action level, must be established. Of particular interest to regulators of leaking underground storage tank (LUST) sites in Delaware is the development of RBSLs for the oxygenated compounds that are added to gasoline to increase octane rating and promote cleaner burning fuel. Whereas methyl-tertiary butyl ether (MTBE) became the first of the oxygenated compounds to gain regulatory attention in Delaware, tertiary-butyl alcohol (TBA) is not far behind. TBA has been detected at LUST sites throughout Delaware and in some cases has been detected in private water supplies. However, Delaware does not currently have a drinking water action level, or maximum allowable exposure concentration, on which to base regulatory decisions regarding TBA.
Toxicological data is inconclusive in classifying TBA as a carcinogen. However, carcinogenic responses are reported in rat and mice studies at extremely high doses. To address TBA in Delaware's Risk-Based Corrective Action Program, the Delaware Division of Public Health must calculate drinking water action levels based on the results of the toxicological data. However, the establishment of TBA action levels could have a tremendous impact on the costs associated with investigating and remediating a LUST site. TBA may add $2000 to $5000 per year in analytical costs alone for an average LUST site in Delaware.  相似文献   

16.
A retrospective review of the current scientific publications on the problems of water protection zones at water bodies is given. The content of regulations on water protection zone in the RF Water Code 2006 now in force is interpreted. The legislations regarding the establishment of water protection zones and riparian buffer strips at water bodies in Russia and other countries are compared and analyzed. The technologies and specifics of the development of geoinformation system “Water Protection Zone and Riparian Buffer Strip of a Water Body” are demonstrated as applied to determining the boundary of the water protection zone and riparian buffer strip for the Uglich Reservoir. Assessment of the anthropogenic load onto a drainage basin within the water protection zone of the Uglich Reservoir and a method for geoecological zoning of its territory are considered as an example.  相似文献   

17.
浅层人工地震勘探是城市活断层探测工程中的重要部分。浅层地震勘探数据库记录测点位置、测线分布图、断点位置等详细信息。本文以宁夏石嘴山市活动断层探测为例,重点介绍了针对石嘴山市内四条隐伏断裂所布设的33条浅层地震勘探测线数据库建设的数据库模型、技术方法、操作技巧及注意事项,为城市活断层探测中基于 ArcGIS等平台系统建立浅层地震勘探数据库提供借鉴。  相似文献   

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张军  陈宇卫  陶月潮  李军辉 《地震》2009,29(2):98-103
地下水位异常在地震前兆信息中占有重要地位, 但观测资料所受干扰较多, 异常成因较为复杂, 探寻水位异常来源对准确判断震情有重要作用。 该文在对安徽霍山皖33井水位1998年以来的资料进行系统清理总结以及环境干扰进行较为详细的调查分析的基础上, 通过观测系统准确性的对比试验, 得出以下结论: 水位基本不受环境因素干扰, 但观测系统是影响水位突变的一个不可忽视的因素。 在排除干扰异常, 提高水位观测质量, 以获取更为可靠的地震前兆信息方面进行了有益的尝试。  相似文献   

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