Improvement of the sediment ecosystem following diversion of an intertidal sewage outfall at the Fraser river estuary,Canada, with emphasis on Corophium salmonis (Amphipoda)     

Arvai JL  Levings CD  Harrison PJ  Neill WE 《Marine pollution bulletin》2002,44(6):511-519

Primary treated sewage effluent from the city of Vancouver, Canada was deposited directly onto the intertidal ecosystem of Sturgeon bank, Fraser river estuary between 1962 and 1988. In response to the degraded sediment conditions an azoic zone developed near the discharge outfall. Effluent discharges into the intertidal zone were almost completely stopped in 1988 with the construction of a submerged outfall. Our studies, conducted between 1994 and 1996, showed considerable improvement in the environment of the mudflat ecosystem, including increased dissolved oxygen, decreased sediment chlorophyll, decreased organic material in the sediment, reduced heavy metals in surficial sediment and increased grain size. The amphipod Corophium salmonis, important in the food web for juvenile salmon and other fish species, recolonized the previously azoic location. At reference stations, C. salmonis density was similar to that observed in previous surveys two decades earlier. Our data strongly suggest that improvement or sediment conditions near the former sewage outfall was a major factor enabling colonization by C. salmonis.  相似文献   

GPI理论研究及美国应用案例对我国的启示     

张燕锋  林逢春 《世界地理研究》2007,16(1):14-20,7

采用GDP核算体系衡量国家和区域的发展存在明显的缺陷，真实发展指数GPI包括经济、社会和环境三个子帐户，包含了一些被GDP所忽略的成本和价值，构建了可量度的可持续发展指标体系来衡量区域经济健康程度和可持续发展能力。本文介绍了GPI的产生和组成帐户．对GPI核算框架与计算方法进行了研究，评介了美国不同区域尺度上的GPI核算应用案例，总结了GPI核算的优点与实施难点，并对在我国开展GPI核算提出了几点建议。  相似文献   

Using satellite remote sensing to survey transport-related urban sustainability: Part II. Results of a Canadian urban assessment     

《International Journal of Applied Earth Observation and Geoinformation》2007,9(3):276-293

The growing importance of urbanization in Canada highlights the need for nationally consistent information on major cities to support effective policy development. A spatially-explicit database, the Canadian Urban Land-Use Survey (CUrLUS), is described. It is a comprehensive source of integrated contemporary land-cover/land-use, demographic and socio-economic information as well as historic land use characterizations from earlier federal initiatives. Satellite remote sensing plays a key role in the form of provision of Landsat-based thematic classifications. The utilization of CUrLUS is illustrated in the quantification of transportation-related energy sustainability indicators, namely, density, urban compactness and land-use mix. The latter shows the greatest promise, being significantly correlated to both work-related median travel distance and percent private vehicle use. Urban transportation is complex and it is argued that indicators based solely on statistical and spatial analysis methodologies are limited in abilities to directly address specific components of this issue, for example, energy consumption. It is recommended that more sophisticated, model-enhanced indicators be developed. We also demonstrate that the land-use/urban-form information of CUrLUS will be a cornerstone in this endeavour.  相似文献   

油气田上方某些化探新指标与油气埋深的关系之研究（二）   总被引：3，自引：0，他引：3  

贾国相  姚锦琪 《矿产与地质》2001,15(3):185-191

试验研究了油气田上方壤中某些气元素，Ba及铁，铜等元素与油气藏的关系，结果显示这些元素对油气藏有明显的指示作用，可作为指标油气藏的存在及埋深的新指标。  相似文献   

Halogen elements as indicator of deep-seated orebodies in the Chadong As–Ag–Au deposit, western Guangdong, China     

Qian Zhang  Shuxun Shao  Jiayong Pan  Zhihao Liu 《Ore Geology Reviews》2001,18(3-4)

Halogen elements play an important role in the metallogenesis of metallic ore deposits and are involved in the whole process of remobilization, transport and precipitation of metallic elements. However, with the exception of fluorine, which, as a component of fluorite and mica minerals, can be occasionally concentrated in ores, Cl, Br and I are hard to enrich in the ores. Investigations have found that the halogen elements tend to diffuse toward country rocks with the development of hydrothermal alteration in the process of their involvement in metallogenesis, especially during the post-ore stage when extensive halogen diffusion halos over orebodies would be formed. Such halogen element diffusion halos over the Chadong As–Ag–Au deposit extend as widely as 200 m. The largest diffusion extent is for I and the diffusion halos of Br are most noticeable 50–130 m away from the orebodies. In areas of ore exposure and the strongly altered zone, the Cl, Br and I contents are close to those of the strata with a V-shaped distribution pattern in the periphery of the mining district. Comparatively speaking, in going away from the altered zone, the major metallic elements Au and Ag in the deposit tend to decrease suddenly to their normal contents in the strata. This variation feature of halogen elements can be used as geochemical indicators for exploring concealed orebodies at depth. In the Chadong ore deposit, halogen element anomalies can be used to predict concealed orebodies at the depth range of 0–200 m.  相似文献   

Conditional Indicator Simulation: Application to a Saskatchewan uranium deposit   总被引：11，自引：0，他引：11  

A. G. Journel  E. H. Isaaks 《Mathematical Geology》1984,16(7):685-718

Mineral deposits frequently exhibit a mixture of rock types in which each type can be identified by a characteristic metal concentration. Such a mixture can be correctly simulated by first reproducing the spatial and geometric configuration of the various rock types in the deposit. Then the grades for each rock type can be jointly simulated and filled in according to their specific coregionalization characteristics. The method of Conditional Indicator Simulation and an uranium—arsenic joint simulation are presented with a detailed, step-by-step application to the Midwest deposit, a high grade uranium deposit in northern Saskatchewan.  相似文献   

山东省可持续发展指标体系初步研究^*   总被引：152，自引：7，他引：152  

毛汉英 《地理研究》1996,15(4):16-23

山东省作为我国沿海地区经济发展较快的省区之一,无论从自然条件、经济发展的区域差异,还是从当前发展中所面临的人口、资源及环境问题,在全国均具有较强的代表性与典型性,可作为研究中国可持续发展的一个“缩影”.本文探讨了建立可持续发展指标体系的基本原则、山东省实施跨世纪可持续发展战略的主要思路,在此基础上提出了指标体系的基本框架及实际应用。  相似文献   

Exploring the link between urban form and work related transportation using combined satellite image and census information: Case of the Great lakes region     

《International Journal of Applied Earth Observation and Geoinformation》2016

Aspects of urban transportation have significant implications for resource consumption and environmental quality. The level of travel activity, the viability of various modes of transportation and hence the level of transportation-related emissions are influenced by the structure of cities, i.e., their urban forms. While it is widely recognized that satellite remote sensing can provide spatial information on urban land cover and land use, its effective use for understanding impacts of urban form on issues such as transportation requires that this information be integrated with relevant demographic information. A comprehensive bi-national urban database, the Great Lakes Urban Survey (GLUS), comprising all cities with populations in excess of 200,000 has been created from Landsat imagery and national census and transportation survey information from Canada and the United States. A suite of analysis tools are proposed to utilize information sets such as GLUS to investigate the link between urban form and work-related travel. A new indicator, the Employment Deficit Measure (EDM), is proposed to quantify the balance between employment and worker availability at different transit horizons and hence to assess the viability of alternate modes of transportation. It is argued that the high degree of residential and commercial/industrial land uses greatly impact travel to work mode options as well as commute distance. A spatial interaction model is developed and found to accurately predict travel distance aggregated at the census tract level. We argue that this model could also be used to explore the relative levels of travel activity associated with different urban forms.  相似文献   

湘中地区微细粒浸染型金矿的找矿标志   总被引：1，自引：0，他引：1  

陈强春 《湖南地质》1998,17(2):100-104

本文总结了湘中地区微细粒浸染型金矿的地层岩性、构造、岩浆岩、成矿系列与地球化学等方面的找矿标志,这无疑对今后的找矿工作具有指导意义。  相似文献   

Indicator favorability theory for mineral potential mapping     

Guocheng Pan 《Natural Resources Research》1993,2(4):292-311

Favorability methods produce a unique measure for mineral potential mapping and quantitative estimation of mineral resources. Indicator favorability theory is developed in this study to account for spatial (auto and cross) correlations of regionalized geological, geochemical, and geophysical fields based on the indicator concept. Target and explanatory indicators are introduced to describe, respectively, direct and indirect evidence of the mineralization of interest. Mineralization is represented by a combination () of a set of target indicators. Indicator favorability theory estimates a regionalized favorability function in two stages: (1) estimate a linear combination of target indicators by maximizing var() and (2) estimate favorability functionF by minimizing estimation variance var[F–]. The model is established on the basis of a conceptual model of target. The favorability estimates can be justified by correlation analysis and cross validation in control areas. The indicator favorability theory is demonstrated on a case study for gold-silver mineral potential mapping based on geophysical, structural, and geochemical fields.  相似文献