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 62 毫秒
1.
Sea-level rise involves increases in the coastal processes of inundation and erosion which are affected by a complex interplay of physical environmental parameters at the coast. Many assessments of coastal vulnerability to sea-level rise have been detailed and localised in extent. There is a need for regional assessment techniques which identify areas vulnerable to sea-level rise. Four physical environmental parameters – elevation, exposure, aspect and slope, are modeled on a regional scale for the Northern Spencer Gulf (NSG) study area using commonly available low-resolution elevation data of 10 m contour interval and GIS-based spatial modeling techniques. For comparison, the same parameters are modeled on a fine-scale for the False Bay area within the NSG using high-resolution elevation data. Physical environmental parameters on the two scales are statistically compared to coastal vulnerability classes as identified by Harvey et al. [1] using the Spearman rank-correlation test and stepwise linear regression. Coastal vulnerability is strongly correlated with elevation and exposure at both scales and this relationship is only slightly stronger for the high resolution False Bay data. The results of this study suggest that regional scale distributed coastal process modeling may be suitable as a first cut in assessing coastal vulnerability to sea-level rise in tide-dominated, sedimentary coastal regions. Distributed coastal process modeling provides a suitable basis for the assessment of coastal vulnerability to sea-level rise of sufficient accuracy for on-ground management and priority-setting on a regional scale.  相似文献   

2.
Integrated assessments (IAs) and integrated assessment models (IAMs) arerecent responses to the inter-disciplinary challenges provided by complexglobal environmental issues such as atmospheric change. This paper discussesan array of integrated assessments, providing an overview of the role of IAsas bridges or foundations for epistemic communities. Formal as well associal, political, and ethical issues are presented. As well as a definition of anIA and an IAM, different forms and approaches of current or proposed IAsare reviewed. Particular stress is laid on the need to maintain the integrity ofthe diverse components of an IA. Finally, reference is made to the need tounderstand the underlying ethical and normative concerns that have promotedthe current interest in IA.  相似文献   

3.
深入推进新时代生态环境质量综合分析工作   总被引:1,自引:0,他引:1  
生态环境质量综合分析是生态环境监测业务流程的重要环节,直接反映生态环境监测服务支撑能力水平。回顾了生态环境质量综合分析的历史沿革与主要成绩,并分析了新时代面临的新形势,如生态系统理论的引领、生态环境考核的要求、信息公开的深化、信息化与大数据的发展等,提出需要在系统化、精细化、信息化和形象化等方向上不断强化,实现新时代生态环境质量综合分析服务生态环境管理和社会公众能力水平的新飞跃。  相似文献   

4.
The Screening Level Concentration (SLC) approach was used to derive Lowest Effect Level (LEL) and Severe Effect Level (SEL) concentrations for nine metals (As, Cr, Cu, Pb, Mo, Ni, Se, U and V) and three radionuclides (226Ra, 210Pb, and 210Po) released to the aquatic environment during the mining and milling of uranium ore. This method was chosen because it allowed for the best use of the considerable historical and current data collected for diverse purposes in the uranium mining and milling regions of Canada (20,606 data points used in the analysis). Except for Cr, all the LELs derived in this study using the weighted method and published sediment quality guidelines (SQGs) were highly reliable (> 85%) in predicting sites unimpacted by uranium mining/milling defined as sites where reductions in the abundance and species richness of benthic invertebrate communities were < 20%. The derived SEL values and corresponding published SQGs (with the exception of Ni) were not reliable predictors (≤60%) of severe impacts on benthic invertebrate communities when severe impacts are defined as a reduction in abundance and species richness ≥40%. Most of the severely impacted sites had sediment contaminant concentrations well below the SEL values. It is concluded that LELs derived using the weighted method can reliably be used in ecological risk assessments as concentrations below which adverse effects on benthic invertebrate communities are not expected. In contrast, it is recommended that SELs not be used in assessments of uranium mining/milling activities as concentrations above which adverse effects are anticipated.  相似文献   

5.
环境风险地图基于地理信息系统(GIS)对信息和数据的空间分析,通过各种风险评估或预测模型,将评估的结果以空间方式展示出来.由于环境风险地图直观、信息量大的优点,有助于环境风险管理以及突发事件的应急反应和实时决策.对风险地图种类作了概述,总结风险制图中需注意的问题以及国内外风险地图的应用研究以及发展情况.  相似文献   

6.
This paper describes the use of statistical regression models to characterize temporal trends in groundwater monitoring data collected between 1980 and 1990 on 15 wells and 13 parameters (195 cases in all) at the KL Avenue landfill site in Kalamazoo County, Michigan. This site was used as a municipal landfill prior to 1980, then was placed on the Superfund site list in 1982 after ground-water contamination was found.Six temporal regression trend models were defined using linear and quadratic regression models. These trends were used to classify each of the 195 cases as: improving, deteriorating, or stable over the 1980–1990 time period. Using these classifications it was determined that there were more than twice as many improving cases as deteriorating conditions at the KL site during this time period. These models provide a method for visualizing and interpreting trends in ground-water quality at individual well locations within the contaminant plume and for assessing the chemical trend behavior of the overall plume. The improving, deteriorating, and stable trend categories were developed for two purposes. The first purpose is to facilitate comprehension of information contained in large amounts of water quality data. The second is to assist communication among the many different groups of people who recommend actions, including remediation responsibilities at Superfund sites, like the KL site.A normal probability model was used in the trend classifications. This model contained provisions to accommodate nondetect data and other abnormal laboratory determinations which can influence the trend selection process. The robustness of this classification procedure was examined using a lognormal probability model. The overall conclusions about the KL site using the lognormal model were similar to those obtained using the normal model. However, some individual trend indications were different using the lognormal model. The Shapiro-Wilk test was used to check the adequacy of both the normal and lognormal models. The lognormal model was found to be a somewhat more adequate model for fitting the KL site data, but was not found to be superior to the normal model for each case.The normal and lognormal models were both found to be suitable for determining overall trend conditions at this site. Both models are recommended for these purposes assuming an understanding of the statistical constraints and hydrochemical context. However, it is recommended that the search for more adequate trend models continues.  相似文献   

7.
Changes in marine ecosystems can be manifested in many different ways, on different temporal and spatial scales. Seabirds are top consumers in marine foodwebs and offer opportunities to detect and assess the biological effects of changes in physical parameters (sea-surface temperature [SST], salinity, depth of thermocline etc.) of the marine ecosystem. We compare six-eight years' of data on the biology (diet, and breeding success) of four species of seabird (arctic tern Sterna paradisaeaand common tern S. hirundo, which feed at the sea surface; and Atlantic puffin Fratercula arctica and razorbill Alca torda, which dive 30–60 m for their prey) breeding on Machias Seal Island (MSI) in the Bay of Fundy with both our own meteorological and oceanographic measurements, and with standard measurements from conventional sources. These are compared with fisheries data on changes in the main prey of all the seabirds concerned (juvenile or 0-group herring Clupea harengus) which are the most direct link between the seabirds and the physical properties of the marine system. We explore relationships between seabird productivity and diet, and other aspects of both herring biology (larval surveys, and fat content) and oceanography (SST data from the island, and remotely sensed data from the entrance to the Bay of Fundy). Timing of laying by puffins followed SST variation at neither the local (MSI) nor regional scales, but at the scale of the North Atlantic, following the trend of populations breeding off northern Norway. The proportion of herring in the diet of terns over 6 years varied inversely with herring larval abundance the previous fall; this relationship was not statistically significant in the puffin and razorbill. A major new finding is the considerable (50%) inter-annual variation in the energy density (fat content) of juvenile herring that are the main seabird prey; breeding success of both species of tern varied in parallel with the energy density of juvenile herring in the diet until the last two years of the study, when sandlance (Ammodytes sp.) and euphausid shrimp predominated in the diet. Our long-term research approach combines traditional population monitoring (of numbers of breeding birds) with demographic, behavioural and environmental monitoring, to provide new understanding of the marine ecosystem as well as of seabirds.  相似文献   

8.
A variety of decision models have been formulated for the optimal selection of nature reserve sites to represent a diversity of species or other conservation features. Unfortunately, many of these models tend to select scattered sites and do not take into account important spatial attributes such as reserve shape and connectivity. These attributes are likely to affect not only the persistence of species but also the general ecological functioning of reserves and the ability to effectively manage them. In response, researchers have begun formulating reserve design models that improve spatial coherence by controlling spatial attributes. We review the spatial attributes that are thought to be important in reserve design and also review reserve design models that incorporate one or more of these attributes. Spatial modeling issues, computational issues, and the trade-offs among competing optimization objectives are discussed. Directions for future research are identified. Ultimately, an argument is made for the development of models that capture the dynamic interdependencies among sites and species populations and thus incorporate the reasons why spatial attributes are important.  相似文献   

9.
Mathematical models are utilized to approximate various highly complex engineering, physical, environmental, social, and economic phenomena. Model parameters exerting the most influence on model results are identified through a sensitivity analysis. A comprehensive review is presented of more than a dozen sensitivity analysis methods. This review is intended for those not intimately familiar with statistics or the techniques utilized for sensitivity analysis of computer models. The most fundamental of sensitivity techniques utilizes partial differentiation whereas the simplest approach requires varying parameter values one-at-a-time. Correlation analysis is used to determine relationships between independent and dependent variables. Regression analysis provides the most comprehensive sensitivity measure and is commonly utilized to build response surfaces that approximate complex models.  相似文献   

10.
The application of geostatistics to spatial interpolation of time-invariant properties in ground-water studies (such as transmissivity or aquifer thickness) is well documented. The use of geostatistics on time-variant conditions such as ground-water quality is also becoming more commonplace. Unfortunately, the detection of temporal changes in spatial correlation through direct comparison of experimental semivariograms is difficult due to the uncertainty in sample semivariograms constructed from field data. This paper discusses the use of the jackknife approach to estimate confidence limits of semivariograms of trichloroethane (TC) and other volatile organic compounds (VOC) in contaminated ground-water in northern Illinois. Examination of the spread of the confidence limits about the semivariograms created from two types of sampling networks are discussed.  相似文献   

11.
Sulphur dioxide (SO2) is one of the main atmospheric pollutants in central Taiwan. This article analyses the SO2 concentration seasonal variations and spatial distribution using data obtained from ten air quality monitoring stations and the Taiwan Weather Bureau. It reveals that SO2 concentration is high in winter and low in summer and that high concentration centers are located south of the Taichung coal-fired power plant, the main source of SO2 emissions in the region.The location of high concentration centers changeswith different prevailing winds. SO2 variations due towind direction are not unique. During short periods,when meteorological conditions are constant, variationin the pollution sources cause variations in thespatial distribution. This has been deduced byappreciation of Intervention analysis to time seriesof hourly data.  相似文献   

12.
This paper examines air quality changes that can arise from implementing specific traffic management schemes, based on the findings of current and past impact assessments. Air quality changes arising from pedestrianisation, traffic rerouting, traffic calming, and bus priority routes are outlined. Case studies are presented where air quality was measured before and after the implementation of a scheme in order to assess how effective traffic management can be in reducing ambient traffic-related pollutant levels. Limitations of past and current studies are highlighted. The need for more monitoring studies, and the need for data from those studies to be used to test and validate a range of suitable numerical models, is emphasised.  相似文献   

13.
There is increased awareness of the need to balance multiple societal values in land use and development planning. Best practice has promoted the use of landscape-level conservation planning and application of the ‘mitigation hierarchy’, which focuses on avoiding, minimizing or compensating for impacts of development projects. However, environmental impact assessments (EIA) typically focus in a reactive way on single project footprints with an emphasis on environmental values and specifically biodiversity. This separation may miss opportunities to jointly plan for and manage impacts to both environmental and social values. Integrated approaches may have particular benefit in northern Australia, where Indigenous people have native title to as much as 60% of the land area and cultural values are closely linked with natural values. Here, we present a novel framework for integrating biodiversity and cultural values to facilitate use in EIA processes, using the Nyikina Mangala Native Title Determination Area in the Kimberley, Western Australia, as a case study. We demonstrate 1) how social and cultural values can be organized and analyzed spatially to support mitigation planning, 2) how social, cultural, and biodiversity values may reinforce each other to deliver better conservation outcomes and minimize conflict, and 3) how this information, in the hands of Indigenous communities, provides capacity to proactively assess development proposals and negotiate mitigation measures to conserve social, cultural, and biodiversity values following the mitigation hierarchy. Based on values defined through a Healthy Country Planning process, we developed spatial datasets to represent cultural/heritage sites, freshwater features, common native animals and plants represented by biophysical habitat types, and legally-protected threatened and migratory species represented by potential habitat models. Both cultural/heritage sites and threatened species habitat show a strong thematic and spatial link with freshwater features, particularly the Fitzroy River wetlands. We outline some of the challenges and opportunities of this process and its implications for the Northern Australia development agenda.  相似文献   

14.
Three statistical models are used to predict the upper percentiles of the distribution of air pollutant concentrations from restricted data sets recorded over yearly time intervals. The first is an empirical quantile-quantile model. It requires firstly that a more complete date set be available from a base site within the same airshed, and secondly that the base and restricted data sets are drawn from the same distributional form. A two-sided Kolmogorov-Smirnov two-sample test is applied to test the validity of the latter assumption, a test not requiring the assumption of a particular distributional form. The second model represents the a priori selection of a distributional model for the air quality data. To demonstrate this approach the two-parameter lognormal, gamma and Weibull models and the one-parameter exponential model were separately applied to all the restricted data sets. A third model employs a model identification procedure on each data set. It selects the best fit model.  相似文献   

15.
This paper presents a new concept to include uncertainty management in energy and environmental planning models developed in algebraic modeling languages. SETSTOCH is a tool for linking algebraic modeling languages with specialized stochastic programming solvers. Its main role is to retrieve from the modeling language a dynamically ordered core model (baseline scenario) that is sent automatically to the stochastic solver. The case presented herein concerns such a study realized with the IEAMARKAL model used by many research teams around the world.  相似文献   

16.
Air quality modelling is primarily the quantative approach. It is more difficult as it demands input data accuracy, uncertainties and the efficient methodologies to judge the extent of models accuracy. As a result, model validation has to be regarded as an integral part of the modelling process. Furthermore, models are often validated on a limited number of testcases therefore, appropriate evaluation procedure must be implemented to ensure these models will be applicable for various conditions. The study presented here was carried out to evaluate theWinOSPM (Preliminary version of windows based Operational Street Pollution Model) for air pollutants viz. CO, NO, NO2, NOx and C6H6 for three street canyons of Nantes (France) and for the three base years 1999, 2000, and 2001. Each street canyon selected for this study has typical and unidentical features. The rue de Strasbourg and Boulevard Victor Hugo have many building exceptions whereas rue Crébillon has not any. Application of the model above to the three street canyons revealed that WinOSPM could be used in the case when measurements are not available. This was justified from the results at rue Crébillon. The special interest was in the benzene modelled values as its content in fuel has been targeted to reduce to 1% for the years 2000 and onwards (from its 5% until the year 1999). The 50 to 70% reduction in the benzene concentrations is found for both the years i.e. in 2000 and 2001. This has further justified that air quality models are useful and interesting tools in optimising emission reduction strategies. Moreover, it is also the new pollutant added to the measurement campaign of Air Pays de la Loire (APL) for the city of Nantes. For benzene weekly averages are estimated from the hourly-modelled values for all the streets and compared with that of measurements. They are found in excellent agreement with each others. For other pollutants annual means and percentiles were compared. The statistical analysis was done to evaluate the models performance using index of agreement and correlation coefficient. The index of agreement (d) and correlation coefficient (r) for all the streets show that estimated concentration levels are in good agreement with that of measurements. From the index of agreements, it can be inferred that model has very less potential for errors. The models sensitivity to building-exceptions was also tested for the rue de Strasbourg. Results did not reflect this feature very well. It is perceived that the influence of this feature might have been suppressed in averaging the annual hourly values. This influence is apparently seen in hourly average time series variations. Finally, WinOSPM model was found a simple but very useful model. It could very well represent the detailed flow and dispersion conditions in urban streets.  相似文献   

17.
Historical records from Ontario's Provincial Water Quality Monitoring Network (PWQMN) for rivers and streams were analyzed to assess the feasibility of mapping regional water quality patterns in southeastern Ontario which spans two major geologic zones, the Precambrian Shield and the St. Lawrence Lowlands, thus serving as a paradigm for much of Ontario. Despite biases toward the populated Lowlands and associated pollution problems, general spatial trends are evident via the analysis of intervariable relations, individual parameter maps and multivariate analysis. Using a robust algorithm designed to identify outliers and abstract underlying bivariate relations, a linear regional hardness-alkalinity relation was derived, where most anomalies proved to be mine drainage impacted sites. Regionally, multivariate ordination reveals that central tendencies of common indicators of ionic strength and nutrient richness correlate positively and that site clusters broadly reflect the transition from oligotrophic Shield waters to eutrophic conditions of heavily agricultural Lowland streams. Results suggest that on the Shield more precisely delineated aquatic regions may be realized by applying GIS to integrate river and synoptic lake survey data. Further synthesis with bedrock and surficial geology, physiography, pedology and other temporally invariant spatial attributes should yield regional patterns of background quality from which locally attainable water objectives might be defined. Additional synoptic surveys of sedimentary Lowland streams may be required as most available sites relflect anthropogenic pollution.  相似文献   

18.
Non-carbon dioxide greenhouse gases are considered in Canada's National Report on Climate Change: Actions to Meet Commitments Under the United Nations Framework Convention on Climate Change. By including all major greenhouse gases and their anthropogenic sources and sinks using best available science, the Report provides a practical illustration of the comprehensive approach policy to implementing the Convention's requirements. In addition to carbon dioxide emissions from fossil fuel combustion, the Report includes information on other sources and sinks for carbon dioxide, and for methane and nitrous oxide. Other gases considered include polyflourocarbons, hydroflourocarbons, and the primary tropospheric ozone precursors, nitrogen oxides and volatile organic compounds. Current Global Warming Potential indices are used to compare and integrate the best estimates of climate change impacts of the major greenhouse gases. The presentation of emission data is intended to be transparent and comparable. The relative quality of the data for various gases and sources is indicated. The existence of environmental, economic, and other benefits to limiting emissions of all greenhouse gases, in addition to carbon dioxide, should be recognized. Continuing assessments and actions on non-carbon dioxide greenhouse gas emissions, both nationally and internationally, are suggested.  相似文献   

19.
A research strategy based upon models of intermediate complexity addressing crucial aspects of global environmental change is presented. The key idea behind that strategy is to compress system complexity either by formal techniques such that first-order aspects are preserved, or to employ semi-qualitative schemes to describe and simulate the dominant dynamical patterns identified by panoramic inspection.Specific realizations of the overall heuristic philosophy are introduced as elements of a comprehensive research program on global change. Topics encompass global climate modeling, a decision analysis framework for managing the global warming problem by balancing adaptation and mitigation efforts, a generic approach to integrated regional climate impact assessment and its implementation in specific regions, as well as a new technique to link regional and global patterns of environmental change by using advanced modeling tools.  相似文献   

20.
We tested whether the semi-automatic program CROCO can replace visual assessments of slides to detect changes in defoliation assessment methods. We randomly selected a series of slides of 24 Norway spruce trees with 220 field assessments made between 1986 and 1995. The slides had been randomly arranged and assessed by three experts without knowledge of the tree number or the year when the slide was taken. Defoliation scores were computed with CROCO. Each tree had thus three different defoliation scores, field assessments, photo assessments and CROCO scores.CROCO scores were less correlated with the field assessments (Spearmans rank correlation: 0.67) than were the slide assessments with the field assessments (0.79–0.83). However, CROCO was not biased against the field scores, while slide assessments systematically underestimated defoliation.In a multi-variate mixed effect model none of the variables tree overlap, tree visibility and light conditions was significant in explaining differences between slide assessors and CROCO scores. The same model applied for the differences from the field scores yielded significant effects for poor light conditions (CROCO and all assessors), for crown overlap (CROCO and one assessor) and for visibility (one assessor). We conclude, therefore, that CROCO can be used to detect past and future changes in assessment methods without bias if poor quality photographs are avoided.  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