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1.
中澳洲Florence剪切带中角闪石晶体优选定向   总被引:1,自引:0,他引:1  
中澳洲Florence剪切带糜棱岩中的角闪石经晶内滑移变形而显示出良好的晶体优选定向,通过对角闪岩石组图的综合分析,并结合前人的实验资料,认识到在高温变形条件下角闪石的滑移系为(100)(001)。该剪切带中角闪石岩组图具不对称型是与角闪石的单一滑移系和该滑移系的初始定向状态有关,是非共轴简单剪切变形的结果,这些不对称的岩组图可用于判断剪切带的运动方向。  相似文献   

2.
The isotopic composition of total dissolved inorganic carbon in seawater was determined as a function of time of day in coral reef environments at Saipan, Abaiang Atoll, Tahiti, Florida and Heron Island on the Great Barrier Reef of Australia. At each locality water collected during the day was enriched in 13C with respect to water collected at night. The form and magnitude of the diurnal cycles is dependent upon the ratio of local biomass to local water mass and on the degree of exchange between local water mass and the open ocean reservoir. Comparison of open and closed system models is made using computer generated δ13C vs. time curves to illustrate modulation by the tidal cycle of the simple diurnal variation in a closed system. The results are of geochemical significance in that the δ13C of CaCO3 precipitated in certain environments is dependent on the time of crystallization. This must be taken into account in isotope ratio studies of both plant and animal secreted carbonates which are preferentially precipitated during certain periods of the day.  相似文献   

3.
黑河中游二白杨叶面积指数动态变化及其与耗水量的关系   总被引:7,自引:0,他引:7  
在黑河中游,利用直接法和热脉冲树干液流仪分别监测了二白杨生长季节的叶面积指数和耗水量动态变化,研究了二白杨叶面积指数动态变化规律及其与耗水量的关系.结果表明:在生长季节,二白杨叶面积指数的增长符合Logistic模型;在树冠结构垂直分布上,1 000~1 400 cm之间二白杨叶面积指数占全树叶面积指数的75.5%;二白杨个体间的叶面积指数与胸径平方和树高乘积呈指数函数关系.当单株叶面积指数从0.44增大到4.94时,二白杨耗水量从42.95 L·d-1增加到140.30 L·d-1.单株二白杨耗水量与叶面积指数之间呈现线性关系.  相似文献   

4.
Documenting whether surface water catchments are in net chemical mass balance is important to understanding hydrological systems. Catchments that export significantly greater volumes of solutes than are delivered via rainfall are not in hydrologic equilibrium and indicate a changing hydrological system. Here an assessment is made of whether a saline catchment in southeast Australia is in chemical mass balance based on Cl. The upper reaches of the Barwon River, southeast Australia, has total dissolved solids, TDS, concentrations of up to 5860 mg/L and Cl concentrations of up to 3370 mg/L. The high river TDS concentrations are due to the influxes of groundwater with TDS concentrations of up to 68,000 mg/L. Between 1989 and 2011, the median annual Cl flux from the upper Barwon catchment was 17.8 × 106 kg (∼140 kg/a/ha). This represents 340–2230% of the annual Cl input by rainfall to the catchment. Major ion and stable isotope geochemistry indicate that the dominant source of solutes in the catchment is evapotranspiration of rainfall, precluding mineral dissolution as a source of excess Cl. The upper Barwon catchment is not in chemical mass balance and is a net exporter of solutes. The chemical imbalance may reflect the transition within the last 100 ka from an endorheic lake system where solutes were recycled producing shallow groundwater with high TDS concentrations to a better drained catchment. Alternatively, a rise in the regional water table following land clearing may have increased the input of groundwater with high TDS concentrations to the river system.  相似文献   

5.
澳大利亚地下水资源管理的法律与政策   总被引:5,自引:2,他引:5  
颜勇 《地下水》2005,27(2):75-77,83
对澳大利亚地下水资源开发利用现状、存在的问题、地下水资源管理与保护方面的立法、管理体制进行了介绍,并对近年来联帮政府在地下水管理方面采取的主要政策进行了重点介绍.  相似文献   

6.
 The mound springs of South Australia are a unique groundwater discharge feature of the Great Artesian Basin (GAB), a deep regional groundwater system that covers 22% of the Australian continent. They are the principal sources of surface water in the arid to semi-arid inland heart of Australia, and have great ecological, scientific, anthropological and economic significance. Excessive development of the Great Artesian Basin over the past century by European activity has seen an overall decline in the flows from the springs. Recent development of the water supply borefields for the Olympic Dam copper-uranium mine in the midst of one the most important spring groups has exacerbated this problem. A review of the history of the Olympic Dam borefields, an analysis of the impacts on the Mound Springs, and future recommendations for the return of environmental flows and protection of the springs is presented. Received: 9 November 1998 · Accepted: 23 February 1999  相似文献   

7.
澳大利亚西北陆架边缘海型被动大陆边缘是目前全球深水区油气勘探的热点地区之一,近年来的一系列深水(>500m)油气重大发现使其备受关注.澳大利亚西北陆架油气分布总体上具有显著的不均一性.平面上呈“内油外气”的分布特征,油气主要分布于富烃凹陷的凹边隆和凹中隆.远岸带深水区发育大型、超大型气田且成群成带分布,近岸带浅水区以发育中、小型油田为主,亦成群成带分布.纵向上呈“上油下气”的分布特征,天然气和凝析油主要富集于上三叠统和中-下侏罗统,石油主要富集于上侏罗统和下白垩统.  相似文献   

8.
Australian government attaches great importance to the management of wetland water environment and the implementation of advanced technology, and has made large processes in the recent decades. Australia is one of the best country in global for wetland management and technology implementation. Based on the analysis of Australian government working method for wetland water environment management, two wetland water environment management and technology dynamic integration cases, and on the comparason ofthe differences of wetland water environment management between the two countries, including Murray-Darling Basin (MDB) and Lake Eyre Basin (LEB), it can be concluded that the success of Australian wetland water environment management is because of the following reasons: the dynamic integration between department establishment and technology, the dynamic integration between public participation and monitoring technology, as well as the dynamic integration between innovation policy and advanced technology. Furthermore, entity management method such as Murray-Darling Basin Authority (MDBA) is more adaptable and has longer lifespan. Such virtual management method as Lake Eyre Basin Intergovernmental Agreement is more flexible and has lower cost. The lessons learned from Australian government can help China manage wetland water environment.  相似文献   

9.
2004年2月、9月、12月和2005年3月,利用澳大利亚产的微侵蚀计(M EM,M icroe-rosion m eter)对湖南郴州礼家洞观测点非岩溶流水中的碳酸盐岩(包括石灰岩和白云岩)试块进行了侵蚀速率的精确测定,共取得数据1550个。用SPSS应用软件对数据进行了处理,发现礼家洞非岩溶流水中的碳酸盐岩的侵蚀速率异常的高,最大的达到了13.6mm/a。在每次测量碳酸盐岩侵蚀速率的同时,使用德国WTW公司生产的MultilineP3多参数自动记录仪,对每个碳酸盐岩试块放置点的水温、pH值、电导率进行了现场监测,并取回水样分析了其中的主要阴阳离子浓度。通过对这些水化学资料的分析,发现礼家洞非岩溶流水的侵蚀能力很强,表现在水的CO2分压很高(可达到12882Pa),而方解石和白云石的饱和指数很低(分别达到-4.78和-10.35)。对比发现,非岩溶流水中碳酸盐岩的侵蚀速率与其方解石和白云石的饱和指数呈负相关关系,即水中方解石和白云石的饱和指数愈低,碳酸盐岩的侵蚀速率就愈高。此外,观察发现,碳酸盐岩试块本身的结构特别是本试验中白云岩的粗晶结构对其侵蚀速率有巨大的影响,反映了机械侵蚀(流水的物理搬运)对侵蚀速率的贡献(可达90%以上),这与传统的将碳酸盐岩试片放入土壤中测得的主要是化学溶蚀速率不同。  相似文献   

10.
Saline seepage zone development and hence dryland salinity is a major environmental problem which many arid to semiarid landscapes in Australia are experiencing. Due to the geological complexity of the regional aquifer system and the heterogeneous nature of the local groundwater system, each groundwater seepage zone in the Spicers Creek catchment, central west, New South Wales, Australia possesses different mechanisms which control its development. Saline seepage zones have formed adjacent to a fault zone, and two experimental sites were established through these groundwater discharge zones to understand geochemical processes which have led to the development of soil sodicity, gully erosion and the flushing of salts into the surface water systems. Seepage zone groundwaters contain a distinctive geochemical signature with elevated concentrations of Na, Cl, HCO3, Ca, Sr, B, As and Li. The mixing of deep saline groundwaters together with ion exchange processes lead to a distinctive seepage zone groundwater chemistry being developed. Altering the landscape features within this rural groundwater system has developed water toxicity for crops, soil sodicity leading to land degradation, and waterlogging problems.  相似文献   

11.
Gamma测井系统在山东莱州海水入侵监测中的应用   总被引:1,自引:0,他引:1  
从澳大利亚引进的AUSLOG测井设备,其Gamma探头具有测量Gamma值、流体电导率、温度等四项功能,精度和分辨率较高,能够实现对井孔岩性和地下水特性的实时测量。采用Gamma测井系统,不仅可以自动采集井孔内垂向分层的定量信息,还可以有效区分低阻岩层和咸水层,在水平剖面的监测中与常规的Cl-浓度监测结果一致,可以直接用于海水入侵的动态监测。Gamma测井系统与其它测井方法联合使用,可以提高海水入侵的动态监测和解译水平。  相似文献   

12.
Petrographic evidence for the hydration reactions: cordierite + water = gedrite + kyanite + quartz, and aluminous hypersthene + water = aluminous anthophyllite, is shown by some granulite facies rocks in the Arunta Complex, near Alice Springs, central Australia. Electron microprobe analyses enable the reactions to be written in some detail. Preliminary thermodynamic and experimental information suggests that the reactions took place at relatively high confining pressures. The reactions may have proceeded more in response to addition of water to the system, rather than a major change in P-T conditions.  相似文献   

13.
Ian Clark  Lynn Brake 《GeoJournal》2009,74(5):441-450
Developing a good working knowledge of water in the landscape and the connectivity between surface and groundwater is germane to a resilient sustainable water supply to sustain human activities and a healthy environment, particularly in the drier parts of Australia. This paper presents a case study in the semi-arid Flinders Ranges of South Australia in which eliciting local knowledge from landholders was a key element in mapping surface and groundwater and investigating the connectivity between water resources. Local landholders provided a vital source of information to augment the limited scientific data initially available on groundwater resources. Groundwater recharge in the region comes from local rainfall onto individual unconnected groundwater catchments. In most of the region water supply seems to have been maintained over the longer term but there are a number of sites where former active springs are now dry or much reduced in size and water supplies from bores have substantially changed in quantity and quality. The involvement of landholders in the investigation of water resources encouraged them to consider the resource context of their stock watering points and incorporate more science into their understanding of the water resources that they rely on. This stimulated interest in investigating more about local water resources and changes in water management practices.  相似文献   

14.
《Engineering Geology》1985,22(1):35-44
Small-boat harbours protected by rubble-mound breakwaters are currently being built along the exposed western and southern coasts of Western Australia. The properties that rocks must have to be suitable for armour blocks on breakwaters are discussed. Particular reference is made to the special problems produced by the remoteness of heavy armour material from the sites of 6796 of breakwaters recently built or being considered in Western Australia. Fuller geotechnical investigations for quarries are warranted in these circumstances.  相似文献   

15.
IGCP448:岩溶生态系统全球对比研究进展   总被引:12,自引:3,他引:9  
章程  袁道先 《中国岩溶》2005,24(1):83-88
综述了IGCP 448项目"全球岩溶地质及有关生态系统对比"(2000-2004)执行四年来所取得的学术成果.其中比较重要的新认识有:(1)岩溶地区的植被,常常是涵养水分,增加含水层的贮水能力,改善水文生态环境的重要因素,但在澳大利亚南部岩溶区广泛分布的桉树,则以其强烈的蒸发作用,而被用于降低地下水位,防治土壤盐碱化;(2)在北方(Boreal) 或温带湿润气候生态区,地下岩溶系统则被用于排除沼泽地区过多积水,偏碱性的碳酸盐岩也有利于中和酸性环境,凡是岩溶发育的地方,都成了主要农业基地;(3)通过洞穴探险发现一类完全不同于靠光合作用产生有机质的生物群--化学自养微生物(甲烷菌);(4)中国西南典型岩溶区的研究表明,表层土壤微生物可以加速碳酸盐岩的溶解作用,并揭示了植物根系与土壤微生物是产生碳酸酐酶(CA)的两个重要供给源.  相似文献   

16.
Lake Urana is a well-preserved relict lake in the semi-arid Riverine Plain of southeastern Australia. A compound lunette at its eastern shoreline consists of a quartz-sand-dominated unit (Bimbadeen Formation), thermoluminescence (TL) dated at 30 ka to 12 ka, and a clay and sand facies unit (Coonong Formation), dated at 55 ka to 35 ka. The intervening period indicates a phase of periodically exposed lake floor and soil formation. The older wet phase conforms well with similar environments recorded from the same period at Lake Mungo. However, the return to high water levels from 30 ka to 12 ka departs sharply from the generally accepted palaeoclimatic model from Australia, which demands severe glacial maximum desiccation and widespread construction of clay lunettes. Although hydrological budgets calculated for Lake Urana and nearby Lake Cullivel require high glacial maximum water levels they do not support higher precipitation.  相似文献   

17.
The response of a multi-layered coastal aquifer in southeast Australia to decades of groundwater pumping, and the groundwater age, flow paths and salinization processes were examined using isotopic tracers. Groundwater radiocarbon and tritium contents decline with distance and depth away from basin margins; however, in the main zone of pumping, radiocarbon activities are generally homogeneous within a given depth horizon. A lack of tritium and low radiocarbon activities (<25 pMC) in groundwater in and around the pumping areas indicate that seasonal recovery of water levels is related to capture of old water with low radioisotope activities, rather than arrival of recently recharged water. Mechanisms facilitating seasonal recovery include release of water from low-permeability layers and horizontal transfer of water from undeveloped parts of the basin. Overall stability in seasonally recovered water levels and salinities for the past three decades indicate that the system has reached a dynamic equilibrium with respect to water balance and salinity, following a major change in flow paths and solute distributions after initial development. Groundwater δ18O, δ2H and chloride contents indicate mixing between fresh meteoric-derived groundwater and marine water at the coast, with the most saline groundwater approximating an 80:20 mixture of fresh to oceanic water.  相似文献   

18.
大地热流对滇池环境的影响与滇池污染治理的新思路   总被引:5,自引:0,他引:5  
滇池经过长达7年、投资40多亿元的治理,在污染源头控制上已经取得了明显成绩,在一定程度上缓解了生态环境的进一步恶化。滇池水体水质至今没有好转的根本原因在于对滇池蓝藻爆发机理的认识没有考虑其所处的特殊地理环境。滇池水体富营养化之后,是由于较高的大地热流背景和四季如春的气候条件使蓝藻得以不停息地繁殖,致使滇池的水生生态系统完全瘫痪,水体完全失去自净能力。“抑制蓝藻的繁殖”和“清除水体中的营养物质”两大问题形成了滇池治理中一个难解的死结。解开死结的有效措施是从抚仙湖调清水给滇池换水,恢复草海,提高湖水自净能力,发展水生生态系统,抑制藻类繁殖。  相似文献   

19.
Information on fatalities from lightning strikes has been extracted from a specially compiled database on natural hazards in Australia. Records dating from 1803–1991 indicate that at least 650 persons have been killed by lightning strikes. Maps and charts show the percentages of victims with respect to age, sex, locality, activity, and other circumstances of the strike. The majority of the 650 fatalities recorded have occurred along the more populous southeastern coast. The overall death rate, from 1910–1989, is 0.08 per 100 000 population. The annual number of lightning fatalities has decreased with time, from a death rate of 0.21 in 1910–1919 to 0.01 in 1980–1989. This trend is more pronounced when population figures are taken into account. The group that has been most at risk in Australia is that of males aged 15–19, followed by males aged 20–34. The male:female ratio of victims has decreased with time but is not approaching equality, being 11.6 in 1910–1919 and 5.3 in 1980–1989. The diurnal and monthly occurrences of lightning fatalities peak at 12.00–18.00 hours and November-February respectively. About 86% of fatalities have occurred outdoors and 14% have occurred indoors. Approximately three-fifths of fatalities have been work-related, and the group of workers that has traditionally been most at risk is that of land-workers. Approximately one-fifth of fatalities have been recreation-related, although this proportion has been increasing with time. The recreational activities of water sports, golf, and cricket have had the greatest number of lightning fatalities. Comparisons are made between these data and the results of other similar studies, both in Australia and overseas.  相似文献   

20.
A conceptual model of the Lake Warden coastal wetlands system, Western Australia, was developed using hydraulic, chemical and stable isotopic data, and formed the basis for a groundwater flow model using the finite element numerical code (FEFLOW). The system to be modeled is complex. The surface water and groundwater within the wetlands system show varying salinity and isotopic composition over short distances and time frames. As a first step, the flow model was calibrated to observed groundwater levels measured since 2001 for both steady state and transient stresses. Particle tracking analysis was conducted to test the source areas of water discharging to the lakes within the wetlands system. The analysis was able to delineate the connectivity between the lakes in the wetland and the flow path. Enrichment of isotopic concentration is evident along a NE–SW transect and the data set provides a means for calibrating a detailed transport model. The study incorporates the varying deuterium composition of the water bodies directly into a transport model and a good match between observed and simulated temporal variations along the transect indicates that the model closely simulated the dynamics of water exchange between the lakes and groundwater within the system.  相似文献   

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