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101.
102.
Abstract: Identifying relationships between landscape hydrogeological setting, riparian hydrological functioning and riparian zone sensitivity to climate and water quality changes is critical in order to best use riparian zones as best management practices in the future. In this study, we investigate water table dynamics, water flow path and the relative importance of precipitation, deep ground water (DG) and seep water as sources of water to a riparian zone in a deeply incised glacial till valley of the Midwest. Data indicate that water table fluctuations are strongly influenced by soil texture and to a lesser extent by upland sediment stratigraphy producing seeps near the slope bottom. The occurrence of till in the upland and at 1.7‐2 m in the riparian zone contributes to maintaining flow parallel to the ground surface at this site. Lateral ground‐water fluxes at this site with a steep topography in the upland (16%) and loam soil near the slope bottom are small (<10 l/d/m stream length) and intermittent. A shift in flow path from a lateral direction to a down valley direction is observed in the summer despite the steep concave topography and the occurrence of seeps at the slope bottom. Principal component and discriminant analysis indicate that riparian water is most similar to seep water throughout the year and that DG originating from imbedded sand and gravel layers in the lower till unit is not a major source of water to riparian zones in this setting. Water quality data and the dependence of the riparian zone for recharge on seep water suggest that sites in this setting may be highly sensitive to changes in precipitation and water quality in the upland in the future. A conceptual framework describing the hydrological functioning of riparian zones on this setting is presented to generalize the finding of this study. 相似文献
103.
Noel D. Uri 《Environmental management》1978,2(5):413-421
A spatial and temporal equilibrium model of production, consumption, prices, and transmission is constructed to determine the efficient pricing and allocation of electrical energy in the United States. Regional coordination is technically feasible and economically attractive. It also maximizes environmental efficiencies. The duplication of electrical generation and transmission facilities yields a misallocation of resources.The utilities put forth specific arguments against coordinated operations. Yet in a fully integrated power system, each region would be expected to maximize the benefits of time diversity by purchasing from outside the region in lieu of the expansion of regional capacity. The Federal Energy Regulatory Commission has not yet made a serious move to encourage regional coordination and planning, but the Commission has the authority to promote such operations if it chooses to do so.The author is an economist with the Department of Energy. The views expressed are those of the author and do not necessarily represent the policies of the Department of Energy or the views of other staff members. 相似文献
104.
Contamination of oxygen-consuming organics (OCOs) was one of the most serious problems in the Yellow River of China. This
study was conducted to analyze monitoring of the data on OCOs contamination for the river in 1980 and during 1992–1999 as
well as examining the effect of suspended solids (SS) on chemical oxygen demand (CODMn) and biochemical oxygen demand (BOD5) of river water. Several significant results have arisen from the study. First, CODMn and BOD5 of the river water showed an increasing trend from the upper to the lower reaches of the mainstream. BOD5 values of river water in 1992 were significantly higher than those in 1980 and showed an increasing trend during 1992–1999.
Second, OCOs in river water of the mainstream was attributed mainly to point sources; the ratio of point to non-point sources
of BOD5 was about 2.81. The load from point sources showed an increasing trend during 1992–1998. In contrast, the load from non-point
sources manifested a decreasing trend during this period; this was caused by the decreasing trend of SS content in river water.
The total load of BOD5 from point and non-point sources displayed an increasing trend during 1992–1998. Third, as the humic substances in SS can
hardly be biologically oxidized in natural conditions but can be oxidized by chemical oxidants such as potassium permanganate,
CODMn was not suitable for being regarded as a parameter reflecting the pollution degree of OCOs in river water with a high SS
content. 相似文献
105.
非点源污染目前已经成为影响水体环境的重要污染。微生物源示踪技术(microbial source tracking,MST)是解决非点源污染的一项新技术,它可以确定污染的宿主来源。肠球菌esp基因和多瘤病毒JCV可以作为检测水体中人源粪便污染的分子标记,其灵敏度和特异性都很高。为分析五大流域水源地是否受到人源粪便的污染,对辽河、海河、淮河、长江和黄河五大流域典型水源地水样进行采集和检测,选取人源粪便特异病原微生物肠球菌的esp基因和多瘤病毒JCV建立了相应的MST分子检测方法。结果表明,五大流域的典型水源地采样点均有可能受到了人源粪便的污染,可为当地相关部门提供技术支持和数据参考。 相似文献
106.
黑河水源地对于保证西安市供水安全具有至关重要的现实意义和长远意义.然而,近年来黑河水库出现水质异常现象,水质有所下降.本文通过对黑河水源地的社会经济和自然环境进行实地调查,分析了水源地的污染源特征,针对性的提出了保护水源地生态环境的对策建议. 相似文献
107.
108.
Kyoo-Man Ha 《Environmental Hazards》2016,15(1):1-15
In the field of disaster management, not many have considered the role and needs of people with disabilities despite their number and condition. The purpose of this paper is to push for specific inclusion of people with disabilities, their needs and participation, into disaster management by studying relevant cases from Indonesia, Korea, and the USA. Qualitative content analysis was used as a major methodology by comparing three factors identified in these nations: government policies, schools and advocacy groups’ efforts, and families and local communities’ awareness. Three models, one from each country, were considered major takeaways from this study: the Indonesian moral inclusion, the Korean medical treatment without exclusion, and the US’ extending social inclusion. In addressing the needs and participation of people with disabilities in disaster management, the following recommendations are put forward: for Indonesia, a move away from olden beliefs and misconceptions on disability (e.g. as a punishment) is imperative. In Korea, relevant fundamental laws (e.g. the Basic Act on Emergency and Safety Management) need to be revised while also studying advanced laws on the subject. For the USA, though the country is already advanced, overall improvement is still needed in terms of association with international non-governmental organizations, increase in the number of (emergency or disaster) response officials, and provision of better medical treatment. 相似文献
109.
A framework for assessing the impact of land use policy on community exposure to air toxics 总被引:1,自引:0,他引:1
Our research focuses on the linkage between land use planning policy and the spatial pattern of exposure to air toxics emissions. Our objective is to develop a modeling framework for assessment of the community health risk implications of land use policy. The modeling framework is not intended to be a regulatory tool for small-scale land use decisions, but a long-range planning tool to assess the community health risk implications of alternative land use scenarios at a regional or subregional scale. This paper describes the development and application of an air toxic source model for generating aggregate emission factors for industrial and commercial zoning districts as a function of permitted uses. To address the uncertainty of estimating air toxics emission rates for planned general land use or zoning districts, the source model uses an emissions probability mass function that weights each incremental permitted land use activity by the likelihood of occurrence. We thus reduce the uncertainty involved in planning for development with no prior knowledge of the specific industries that may locate within the land use district. These air toxics emission factors can then be used to estimate pollutant atmospheric mass flux from land use zoning districts, which can then be input to air dispersion and human health risk assessment models to simulate the spatial pattern of air toxics exposure risk. The model database was constructed using the California Air Toxics Inventory, 1997 US Economic Census, and land assessment records from several California counties. The database contains information on more than 200 air toxics at the 2-digit Standard Industrial Classification (SIC) level. We present a case study to illustrate application of the model. LUAIRTOX, the interactive spreadsheet model that applies our methodology to the California data, is available at http://www2.bren.ucsb.edu/~mwillis/LUAIRTOX.htm. 相似文献
110.
Reed MG 《Environmental management》2007,39(1):30-49
Advocates of community-based approaches to environmental management argue that by respecting local circumstances, skills,
and concerns we may improve the prospects of achieving environmental sustainability; yet, within nation states such as Canada,
environmental conditions, management and enforcement costs and capabilities, and power differentials within and among civic
and public sectors may result in a highly differentiated capacity for environmental management across different localities
and regions. This article draws on insights of political ecology to 1) create a conceptual framework that identifies key elements
shaping regional environmental management regimes and to 2) undertake a comparative analysis to assess how elements interact
to generate uneven management outcomes. I compare experiences of two Canadian biosphere reserves designated in 2000: Clayoquot
Sound, BC; and Redberry Lake, SK. Analysis reveals that differences in governance and institutional capacities in the biosphere
reserves are key to explaining uneven local outcomes. Where the public and civic sectors are strong, a robust and publicly
vetted form of management will emerge. Where these sectors are weak and land is held as private property, environmental nongovernmental
organizations can set the type and level of management, to the exclusion of effective civic and state involvement. This result
may improve environmental sustainability but hinder social sustainability of a management regime and raises questions about
the efficacy of community-based management. 相似文献