首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 46 毫秒
1.
万峰湖水环境质量调查及分析   总被引:1,自引:0,他引:1  
通过对万峰湖水环境质量进行的调查和监测,对万峰湖的水质状况、富营养化状态进行了评价。结果表明,万峰湖的5个主要入湖河流和湖区的水质劣于《地表水环境质量标准》GB3838—2002Ⅲ类标准,大部分水域水质类别达劣Ⅴ类,其中主要超标项目为TP、TN;万峰湖83%的区域属于富营养型;为了防止湖泊水质恶化和富营养化的加重,提出了水环境保护的相关措施。  相似文献   

2.
空间插值法在湖泊水污染现状评价中的应用研究   总被引:2,自引:0,他引:2  
"以点代面"在环境现状评价中应用较为普遍,由于点的位置、区域面积大小及形状等原因,(监测)点值很难代表区域平均水平.将地理信息系统(GIS)的空间插值技术应用于评价中,可以改善结果的合理性及可解释性.通过对各插值方法进行选择后选取反距离加权法与Kriging法对长湖的污染现状进行分析,得出大部分水域水质都处于Ⅴ类和劣Ⅴ类,只是在其主要出水口习家口和刘岑闸附近的小部分水域水质可以达到Ⅳ水质标准.同时发现反距离加权法与Kriging法都具有较高的精度,只是Kriging法略优于反距离加权法.图8,表1,参9.  相似文献   

3.
东江流域水质评价   总被引:1,自引:0,他引:1  
通过对东莞段东江流域水样进行采集和检测,选用常规指标TP、BOD、NH,一N、CODcr、铜和铅6项水质参数,采用综合污染指数法对其水质现状和主要污染物进行评价和分析。主要污染物是CODcr和TP,重金属并无超标现象。  相似文献   

4.
2014-2015年对深圳湾福田红树林自然保护区水质进行定期监测, 分析水质状况的空间和季节变化特征。结合2009-2014年福田红树林自然保护区的水质监测结果, 阐明红树林水环境质量的年际变化趋势。结果表明: 1) 保护区内水体溶解氧(DO)普遍较低, 营养盐和有机污染物普遍超标, 其中TN, TP, COD和BOD的平均浓度分别为地表水Ⅴ类水质标准的4, 2.6, 1.3和1.3倍, 富营养化程度严重, 枯水季的污染程度显著高于雨季; 2) 年际变化显示, 2009-2014年, TN和TP呈先下降后上升的趋势, BOD总体上保持上升趋势, COD保持下降趋势; 3) 福田红树林保护区内水质重金属污染已得到改善, 有机污染则有不断加重的趋势, 外源性污染物的输入是主要污染来源, 亟需采取控制措施。  相似文献   

5.
太湖春季水质参数空间格局分布的克里格内插估计   总被引:1,自引:0,他引:1  
为了解湖泊水质参数的空间格局分布,以太湖为试验区,对其2004年4月26个观测点的15项水质参数,如水温、透明度、叶绿素、DO、pH值、BOD5、CODMn、CODcr、NO2-N、NO3-N、NH3-N、CL^-、SO4^2-、TN和TP进行了统计分析.采用克里格内插方法,估计各项水质参数的空间格局分布.结果直观地反映了各项水质参数在空间上的分布,说明了太湖的污染状况.表明这15种水质参数具有一定的空间相关性,太湖以北部的梅梁湾和五里湖污染最为严重.  相似文献   

6.
利用模糊综合评判方法对2009年辽河口湿地的水环境质量进行了综合评判.17个样点的监测结果显示,7月份辽河口湿地水质大多数样点化学需氧量(COD)和全氮(TN)超地表水环境质量IⅤ类标准,全磷(TP)、氨氮(NH3-N)和重金属(Cd、Pb、Cu、Zn)优于III类标准.运用统计学方法从8个监测指标中遴选出了COD、TN、TP、NH3-N、Cd和Pb 6个指标作为参评因子,采用污染贡献率方法确定单因子权重系数,评判结果表明辽河口湿地大多数样点水质级别为Ⅴ,水环境质量较差.  相似文献   

7.
通过对上海市某河道水质的实测调查数据,分析了河水富营养污染因子的时空分布特征,采用综合营养状态指数法对水体富营养污染程度进行了评价,结果表明:河水水质指标Chla,TN,CODMn均呈现夏季高、冬季低的变化规律,而SD冬季高、夏季低,TP随季节变化不显著。7月水体污染最严重,水体的CODMn,TN平均浓度均超Ⅴ类水质标准约2倍,Chla与SD处于劣Ⅴ类水平,TP处于Ⅴ类水平,该河道氮和有机物污染严重。冬季,水体主要为轻度富营养状态,春、秋季,水体主要处于中度富营养状态,夏季6月,在4~6河段出现了重度富营养状态,7~8月水体整体呈现重度富营养状态,河道易暴发水华。控制外源污染物排入,并加强河道水质监测、评价和富营养状态预报,是防治河流黑臭水华,实现城市碧水的关键。  相似文献   

8.
根据2005—2010年对南四湖水体水质监控资料,对N、P的分布现状、季节变化特征、NIP比值、网箱区与网围区N、P分布特征进行比较,分析与评价了湖区渔业养殖对水体TN、TP的影响.结果表明:南四湖水域营养盐多数时间为TN、TP共同限制水体,TN、TP含量有明显的季节变化,5—9月呈上升趋势,10月份明显降低.非养殖区TN、TP含量略大于养殖区,网箱养殖对N、P的影响大于网围养殖.通过水质标识指数法评价南四湖水质为V-劣V类水,明显低于功能目标要求.  相似文献   

9.
陈菡雯  万帆  黄浩  胡辉 《科学技术与工程》2020,20(21):8766-8771
水环境污染是困扰城市发展和影响人居生活的重要因子。为探索研究河湖水环境改善措施,尤其是研究与人居环境密切相关的城市内湖水环境提升,以武汉市南湖为例,开展了典型城市公园型湖泊的水质提升问题。通过对南湖汇水范围内污染物来源的进行精细化定量解析,结果结果表明南湖入湖总氮(TN)和总磷(TP)负荷分别为835.6 t/a和92.56 t/a;污染负荷空间分布有三个典型峰值区域,其面积仅占汇水范围的10.7%,而其TN产污负荷占25.18%,总磷产污负荷占23.97%。采用狄龙模型计算得出南湖水域TN环境容量为315.2 t/a,TP环境容量为21.01 t/a。在完成城镇生活污水和底泥释放中60%TN去除和75%TP去除的基础上,同时地表径流中TN控制率达到67%、TP控制率达到87%,即TN和TP排放量控制在环境容量限值以内,可使TN浓度达到1.5 mg/L,TP浓度达到0.1 mg/L,南湖水质总体达到地表水Ⅳ类要求。基于环境容量分析的入湖污染物来源定量解析,以及进一步对汇水范围内污染负荷的空间分析,可为河湖水环境污染治理措施的合理安排提供科学依据。  相似文献   

10.
武汉市沙湖纳污口水环境研究   总被引:1,自引:0,他引:1  
参照国内外有关湖泊水环境状况的研究,对湖北大学纳污口(排入沙湖)和沙湖水质进行实验监测研究,分析沙湖各水质参数之间的定量关系,并参照《地表水环境质量标准》(GB3838-2002)对湖北大学纳污口所排污水水质作了定量的评价,以及应用综合营养状态指数法对沙湖水体的富营养化程度进行评价.结果表明:(1)湖北大学纳污口所排出废水的各项主要指标均超标,特别是氨氮(NH3-N)、总磷(TP)、化学需氧量(CODcr)指标均严重超标;(2)沙湖水体的化学需氧量、五日生化需氧量(BOD5)、氨氮、总氮(TN)、总磷(TP)等指标严重超标,有的已达Ⅴ类、甚至是劣Ⅴ类水质,这与沙湖的功能区划的Ⅳ类水质不相符合;(3)沙湖中总磷(TP)平均浓度与生物量的代表参数叶绿素a(ch1 a)之间存在明显的正相关关系;(4)沙湖水体已达中度富营养化,水质情况比较差,尤其是枯水期的富营养化程度明显比平水期、丰水期严重.  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

15.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

16.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

17.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

18.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

19.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

20.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号