Laboratory longitudinal diffusion tests: 1. Dimensionless formulations and validity of simplified solutions

To obtain reliable diffusion parameters for diffusion testing, multiple experiments should not only be cross-checked but the internal consistency of each experiment should also be verified. In the through- and in-diffusion tests with solution reservoirs, test interpretation of different phases often makes use of simplified analytical solutions. This study explores the feasibility of steady, quasi-steady, equilibrium and transient-state analyses using simplified analytical solutions with respect to (i) valid conditions for each analytical solution, (ii) potential error, and (iii) experimental time. For increased generality, a series of numerical analyses are performed using unified dimensionless parameters and the results are all related to dimensionless reservoir volume (DRV) which includes only the sorptive parameter as an unknown. This means the above factors can be investigated on the basis of the sorption properties of the testing material and/or tracer. The main findings are that steady, quasi-steady and equilibrium-state analyses are applicable when the tracer is not highly sorptive. However, quasi-steady and equilibrium-state analyses become inefficient or impractical compared to steady state analysis when the tracer is non-sorbing and material porosity is significantly low. Systematic and comprehensive reformulation of analytical models enables the comparison of experimental times between different test methods. The applicability and potential error of each test interpretation can also be studied. These can be applied in designing, performing, and interpreting diffusion experiments by deducing DRV from the available information for the target material and tracer, combined with the results of this study.     

Sustainable Health Risk Management and the Role of Cross-Disciplinary Professionals in Developing Countries: Mexican Experience

The paper argues health risk management in Developing Countries cannot be sustainable unless it is conceived, planned, implemented and maintained by community-led multi-stakeholder groups using an integrated capacity building process with five components: (1) education and awareness raising; (2) strengthening information resources and decision making; (3) strengthening regulations and compliance; (4) improving basic sanitation infrastructure; and (5) stimulating the market for support products and services for health and environment sectors. Occupational and environmental health professionals with cross-disciplinary understanding are uniquely qualified to build much-needed bridges between stakeholders, risk science and policy. They should adopt a cost-effective mentality, adapting models/methods used in developed countries to developing country contexts, negotiating political obstacles and understanding cultural differences in risk sources, exposures and perceptions. Stakeholders – health professionals, community representatives, officials, NGOs/advocacy groups, industries, and providers of products/services – collaborate to detect needs, mobilize resources, design, develop, implement, consolidate and maintain interventions to priority problems. Field experience in Mexico supports the argument. This sustainability process is adaptable to other keystone development sectors like soil and water resources stewardship, biodiversity conservation, agriculture and energy.     

Sustainable tourism management and development of a Greek coastal municipality

A process is presented to facilitate the sustainable management and development of tourist destinations. Based on a specific reforming of the Limits of Acceptable Change planning system and combined with the Tourism Carrying Capacity concept into a common framework, specific steps are described to integrate environmental, social and economic information of a tourist destination into indicators, which are afterwards compared with reference conditions. The Leopold matrix is applied to identify and classify restrictions of development and provide the basis for negotiations between managers, stakeholders and local communities. Through a feedback process of continuous monitoring and adjustment, the aim is to focus developmental activities on restricting factors until all indicators upgrade to reference. A case study at a Greek coastal municipality (Ilida – western Greece) is applied to demonstrate the process. Activity zones are identified and 18 indicators are selected. Results suggest high potential for tourism development of the area. However, low scores are assigned to 8/18 indicators, reflecting restrictions, requiring priority under a sustainable development plan. The proposed process offers managers and stakeholders the ability to easily visualize/identify restrictions and assign developmental priorities within a step-by-step upgrading process, toward the sustainable management and development of tourist destinations.     

西北地区水资源承载力弹性区间综合分析

阐述了水资源承载力的内涵,通过分析弹簧的弹性形变引出了水资源承栽力的弹性区间,并根据西北地区的实际情况得出生态水的用量决定水资源承载力弹性区间的范围。定量分析了节水系数与污水处理率对生态用水量的影响,最后提出了增加西北地区水资源承栽力弹性区间的对策。     

昆明市环境承载力空间管治研究

根据环境承载力的现状及其分布,为昆明市的城市可持续发展合理利用环境承载力,制订差别化产业发展和环境保护政策,提出了昆明市环境承载力空间管治分区及管治策略,为形成合理的空间开发结构提供科学依据和技术支撑.     

长白山旅游景区生态环境状况评价

采用生态环境状况指数(EI)对旅游景区生态环境状况进行评价.结果表明:1960年、2005年和2009年旅游景区EI值均大于75,生态环境为优;与1960年比,2005年和2009年EI值分别减小0.99和1.50,生态环境逐年变差,并呈加剧之势;Ibio、Iveg、Iero和Ienv值均分别减小1.43、0.87、1...     

廊坊市大气环境质量与环境容量研究

根据廊坊市2003～2008年空气监测数据,采用灰色模型GM(1,1)对该市大气环境质量主导因子PM10、SO2和NO2进行模拟预测,采用宏观总量控制A值法对理想大气容量进行计算分析,最终建议在工业污染源、生活污染源、交通污染源和建筑扬尘污染源4个方面采取必要措施保护廊坊市的大气环境。     

长江,嘉陵江重庆段水环境容量研究

根据特定的水环境容量定义，推导出计算长江嘉陵江重庆干流段和城区段水任人唯贤容量的数学模型，并对计算条件进行了叙述，同时对计算出的水环境容量对空分布也作了较详细的分析。     

西安广运潭生态景区旅游环境容量研究

建立了一套旅游环境容量指标体系,给出了各指标的含义和计算公式,并据此对西安广运潭生态景区旅游环境容量进行了定量分析,计算出了其值,计算结果较为科学,具有一定的可操作性,对广运潭的规划管理有一定的指导意义。     

区域水环境自净能力的定量评价

根据地震等级和风力等级的计算原理 ,提出了区域水环境自净能力等级的概念。它是描述一个地区水环境自净能力大小的定量指标。自净能力等级越高 ,区域水环境的自净能力越强。该指标从理论和应用方面来说都具有许多优点 ,概念明确 ,简单易行 ,具有重要的现实意义