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191.
Thomas Jenkin 《The Australian geographer》1999,30(3):355-371
The exploitation of natural resources within areas that are valued for their environmental qualities raises competing emotions. This paper considers a proposal to undertake petroleum exploration in an area of recognised environmental value, namely, the Coongie Lakes of far north-east South Australia. In development cases such as this, the level of inquiry needs to address environmental, social, cultural and economic issues from a range of interest groups; therefore, the process of assessment is a crucial factor in minimising conflict and meeting the wishes of the stakeholders. In the example of Coongie Lakes, the chosen method failed. This paper discusses the perspectives of the major stakeholders, the process of assessment undertaken, and the criticisms directed at this process. The apparent inadequacies of the assessment process undertaken are then highlighted, and an alternative assessment procedure suggested. 相似文献
192.
Arto Itkonen Virpi Marttila Jarno Meriläinen Veli-Pekka Salonen 《Journal of Paleolimnology》1999,21(3):271-294
An 8000-year record of palaeoproductivity, based on the chemical and chironomid stratigraphies from Lake Päijänne, S. Finland, was assessed with respect to known morphometric, climatic and anthropogenic events. A gradual trend of dystrophication and an associated decrease in aquatic production was detected during the Holocene, with the following exceptions: (1) high diatom and chironomid production around 8000-6000 cal yr BP, (2) eutrophication around 2000 cal yr BP, and (3) an anthropogenic signal during the last few decades.The changes in chironomid assemblages, before the past few decades, have mainly been shifts in concentration, but not in species composition. Variation in chironomid production was mainly explained by the accumulations of biogenic silicon, carbon and organic matter. Nutrient availability seems to be important in controlling biogenic silicon, which we use to infer past diatom production. The high production ca. 8000-6000 cal yr BP and the fluctuation in chironomid influx after ca. 2000 cal yr BP, however, were probably caused by the proposed warm/dry and cold/wet conditions during these times, respectively. These results highlight the sensitivity of boreal shield lake ecosystems to climatic forcing. In contrast, the pronounced change in the morphometry of the basin around 7000 cal yr BP had little effect on the trophic state of the lake. The human-induced trophic change during the past few decades has affected the Lake Päijänne ecosystem to an extent never experienced before during the last 8000-years. 相似文献
193.
194.
对珠江口盆地两口钻井95个泥质岩样粘土矿物X衍射分析资料的定量研究表明,若反应是以消耗蒙皂石为代价形成伊利石,则反应符合溶解-沉淀机理,但除此以外,蒙皂石还可以净溶解或新增伊利石层的方式加大I/S比。蒙皂石在渐进成岩过程中的框架性行为模式具有三级控制,按顺序分别由温度、基本离子成分和动力学因素控制特定温度段内蒙皂石行为过程的起始和终结、行为过程的方式和行为过程的速率和程度。渐进成岩过程中I/S比的变化主要与第三级控制有关,而游离状蒙皂石和伊-蒙混层粘土的含量变化则是第二三两级共同控制的结果。 相似文献
195.
M. F. Grasso R. Clocchiatti F. Carrot C. Deschamps F. Vurro 《Environmental Geology》1999,37(3):207-217
The aim of this paper is to verify whether lichens have the capacity to accumulate atmospheric contaminators linked to volcanic
activity. About 100 lichens were collected in 1994 and 1995 from two active volcanic areas in Italy: Mount Etna and Vulcano
Island. Twenty-seven elements were analyzed for each individual lichen using Instrumental Neutronic Activation Analysis and
Inductively Coupled Plasma-Mass Spectrometry. Lichen composition reflects the contribution of the volcanic particulate material,
and the two areas investigated can be distinguished on the basis of the concentration of some lithophile elements. Moreover,
the distribution in lichens of the elements (As, Sb, Br, Pb) – derived from gas emissions (plume, fumaroles) – also shows
different geochemical trends on Mt. Etna and Vulcano.
Received: 20 April 1998 · Accepted: 4 July 1998 相似文献
196.
An attempt is made to assess the sensitivity of food production to various aspects of global change and environmental degradation during the next few decades. As a tool for this study a spreadsheet accounting system for food demand and supply is used. Taking into account the uncertainties of the various influencing factors, such as new technologies, improved management, increased fertilizer use, climatic change, expansion of irrigation, soil degradation and loss of agricultural land, the study indicates that one cannot say with any certainty whether or not food supply will meet expected demand in 2025, especially in Less Developed Countries. Bringing into use 10% of available potential cropland will make little difference. 相似文献
197.
南京地下水开采引起的环境地质问题及防治对策 总被引:3,自引:0,他引:3
近些年来,南京市的地下水开采量呈上升趋势,引发了泉水干涸、地面沉降、塌陷、水质恶化等一系列环境地质问题。对此进行了全面细致的分析,并提出了防治这些环境地质问题的措施,对我国城市地下水资源的合理规划和管理具有一定的借鉴意义。 相似文献
198.
下扬子区孤峰组放射虫化石带划分及环境分析 总被引:1,自引:0,他引:1
下扬子区中二叠统孤峰组线硅质岩中的放射虫化石极其丰富,这些化石主要阿尔拜虫类(albaillellids)球形多囊虫类(Sphericalpolycystine)十字多囊虫类(stauraxonpolycystine)组成,其中以Pseudoalbaillellacalprata.P.longtanensi,P.cf.longicornis,HegleriaMammilla,Follicucull 相似文献
199.
Mahmoud S. Alyamani 《GeoJournal》1999,48(4):291-297
In Wadi Tharad the groundwater has been subjected to hydrochemical study to identify the process (s) that led to the formation
of relatively highly saline water in shallow alluvial aquifer. The chemical analyses results show that the groundwater salinity
was highly variable and randomly distributed along the wadi course. This variation could be attributed to intensive evaporation
on effluent prone surface irrigation water that led to precipitation of evaporates (e.g., calcite, dolomite, gypsum and probably
halite). The intensive irrigation practice through mineral dissolution recharged the groundwater with a marked increase in
the salinity. The local hydrogeological condition is also involved in determining the risk of the groundwater salinity as
a consequence of irrigation practice.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
200.
Annie G. BHOWMIK 《国际泥沙研究》1999,(2)
1INTRODUCTIONTheUpperMississippiRiver(U-MR)extendsfromCairo,Illinois,totheheadwaiersoftheMississippiRiver(MR)nearLakeltascainMinnesota.Theentirerivercanbedividedintotwomajorreachesf1)theUpperMississippiRiverfromheadwaierstoCairo,Illinois,totheconfluenceoftheOhioRiverwiththeMississippiRiver,and2)theLowerMississippiRiver(LMR)fromCairo,Illinois,totheGulfofMexico.FigureIshowsthisdivision,includingabreakdownoftheentireriverintofive(5)segmentswhichwillbedescribedinasubsequentsectio… 相似文献