Agent‐Based Modeling to Simulate Contamination Events and Evaluate Threat Management Strategies in Water Distribution Systems

In the event of contamination of a water distribution system, decisions must be made to mitigate the impact of the contamination and to protect public health. Making threat management decisions while a contaminant spreads through the network is a dynamic and interactive process. Response actions taken by the utility managers and water consumption choices made by the consumers will affect the hydraulics, and thus the spread of the contaminant plume, in the network. A modeling framework that allows the simulation of a contamination event under the effects of actions taken by utility managers and consumers will be a useful tool for the analysis of alternative threat mitigation and management strategies. This article presents a multiagent modeling framework that combines agent‐based, mechanistic, and dynamic methods. Agents select actions based on a set of rules that represent an individual's autonomy, goal‐based desires, and reaction to the environment and the actions of other agents. Consumer behaviors including ingestion, mobility, reduction of water demands, and word‐of‐mouth communication are simulated. Management strategies are evaluated, including opening hydrants to flush the contaminant and broadcasts. As actions taken by consumer agents and utility operators affect demands and flows in the system, the mechanistic model is updated. Management strategies are evaluated based on the exposure of the population to the contaminant. The framework is designed to consider the typical issues involved in water distribution threat management and provides valuable analysis of threat containment strategies for water distribution system contamination events.     

Water Adherence Factors for Human Skin

On incidental dermal exposure to chemicals in water, a key exposure factor is the amount of water adhering to skin. Although soil adherence factors have been developed for risk assessment, measurements of water adherence on human skin have not been described. In the Environmental Protection Agency's (EPA's) dermal risk assessment guidance, dermal dose from environmental exposures is based upon the flux rate across the skin, which assumes that an unlimited amount of chemical is available for absorption. This assumption is applicable to certain exposure scenarios such as swimming and bathing. However, exposures to contaminated water frequently involve scenarios where the available chemical is limited by the amount of water adhering to the skin, for example, during accidental splashes. We conducted studies in human volunteers to investigate water adherence per unit area of skin after brief contact with water. In two sets of experiments, either water was applied with a micropipette to 10‐cm² areas of the lower leg, foot, and hand, or the foot and hand were briefly immersed in water. In males, using a micropipette, water adherence ranged from 1.93 (foot) to 7.13 μL/cm² (lower leg). In females, it ranged from 1.10 (lower leg) to 4.83 μL/cm² (hand). Hand and foot immersion resulted in relatively higher values of 6.89 and 5.17 μL/cm², respectively, in males, and 5.40 and 6.39 μL/cm² in females. Water adherence was affected by amount of body hair and type of exposure. Water adherence factors can be used to calculate the applied dose per unit area for exposures involving intermittent water contact.     

Do Reports on Drinking Water Quality Affect Customers' Concerns? Experiments in Report Content

The Safe Drinking Water Act Amendments of 1996 required U.S. utilities to report on drinking water quality to their customers annually, beginning in fall 1999, on the assumption that such reports would alert them to quality problems and perhaps mobilize pressure for improvement. A random sample of New Jersey customers read alternative versions of a water quality report, in an experiment on reactions to water quality information under U.S. Environmental Protection Agency (USEPA) rules. Experiment design was 2 x 3 + 1: two versions each--one with, one without, a violation of a health standard--of a report that was (1) Qualitative (without water quality numbers, thus not meeting USEPA rules); (2) Basic, with minimal information meeting the rules; or (3) Extended, adding reading aids and utility performance information; plus a control instrument without any hypothetical report. Results of ANOVA suggest the reports will have less effect than hoped or feared. These manipulations were successful: people reading the Qualitative versions were less likely to say that the report gave the amounts of substances found in the water, and those reading Violation versions were more likely to report a violation of a health standard. The main differences in responses to the report involved the judged adequacy of the information, and to a lesser extent responses on a Concern scale (constructed from measures of concern, judged risk, clean-up intentions, distrust of utility information, and doubt that the utility was doing all it could to improve water quality). Overall judgments of water quality and utility performance did not change, either relative to the controls or in before versus after responses. Qualitative reports performed worse than others, confirming the decision to have utilities report actual contaminant levels. Extended reports did only slightly better than the Basic versions on these measures. Many respondents had trouble identifying the presence or absence of substance amounts or violations, despite their seeming obviousness (e.g., in a "bottom line" summary on the front page of each report), suggesting many were not processing this information carefully. However, the pattern of responses for those who accurately identified the presence or absence of substance amounts or violations did not differ substantially from that for the group as a whole. Generic risk beliefs (serious local environmental problems; lack of control over risks to one's health) dominated demographic variables, attitudes toward utility water quality or trustworthiness, and the content and format of water quality reports in influencing concern about drinking water quality. Previous empirical and theoretical evidence for lack of change in public risk attitudes due to one-time or infrequent communications--e.g., role of personal experience, perseverance of prior trust or distrust--seems to be confirmed for annual water quality reports.     

纤维素吸水树脂的合成及应用研究

叙述了以纤维素为原料制备纤维素吸水树脂的方法,并对其在水泥固化过程中的作用和对水泥硬化后的强度的影响进行了探讨,结果是加入纤维素吸水树脂后不仅能增强水泥的保水性而且能提高水泥强度.     

"最严格水资源管理制度"对京津冀地区农业干旱的影响

京津冀地区多年来一直是水资源匮乏的区域，近年来随着"最严格水资源管理制度"的落实，当地的农业生产和社会经济的发展受到了严重制约。因此，系统研究京津冀地区的干旱情况，精确预测和评估旱情发生的规律和危害，可为区域水资源调控和相关部门决策提供科学依据，并对未来农业用水提供合理的解决方案。基于2000-2016年5-10月份MODIS NDVI和LST月数据，利用TVDI模型对京津冀地区进行干旱监测，探讨其干旱的时空分布，在此基础上，结合MCD12Q1 Land cover type2土地覆盖数据的马里兰分类方案，将土地覆盖分类修改合并为两大类：农用地和非农用地，作为提取农用地TVDI的底图，并进一步分析农用地受灾的情况。结果表明：2013年之后，"最严格水资源管理制度"的提出对京津冀农用地影响非常大，在很大程度上导致农用地干旱面积增加。     

少数民族地区水利水电工程移民问题探讨

西部少数民族地区是我国水利水电开发的重点区域。少数民族地区移民的特殊性对移民安置的实施提出了挑战。综合利用文献和田野经验,在梳理少数民族地区移民安置主要研究领域的同时,分析了研究的前沿科学问题。已有研究主要围绕少数民族地区移民的搬迁补偿、移民安置、移民适应、移民融合等问题。后续研究中,需要关注少数民族人地关系与生计、少数民族宗教信仰与文化习俗及其恢复补偿、少数民族移民可持续发展研究等。     

Perception of Ecological Risk to Water Environments

This paper examines lay and expert perceptions of the ecological risks associated with a range of human activities that could adversely affect water resource environments. It employs the psychometric paradigm pioneered in characterizing perceptions of human health risks, which involves surveys to obtain judgments from subjects about risk items in terms of several important characteristics of the risks. The paper builds on a previous study that introduced ecological risk perception. This second study employs a larger, more diverse sample, a more focused topic area, and comparisons between lay and expert judgments. The results confirm that a small set of underlying factors explain a great deal of variability in lay judgments about ecological risks. These have been termed Ecological Impact, Human Benefits, Controllability , and Knowledge. The results are useful in explaining subjects' judgments of the general riskiness of, and need for regulation of, various risk items. The results also indicate several differences and areas of agreement among the lay and expert samples that point to potential key issues in future ecological risk management efforts for water resources.     

丰水地区虚拟水投入产出分析——来自江西的实证

构建了区域水资源投入产出模型,通过对丰水地区的典型代表省份江西的农业、工业及其他产业虚拟水消费量、贸易量的计算,得出了各产业间虚拟水净转移以及区域间虚拟水的输入输出量,建立产业间虚拟水转移矩阵,量化了产业间虚拟水的转移情况。结果认为,农业是虚拟水最大的净转移和输出部门,其所利用的水量实际上向制造业大量转移。该结论从投入产出分析视角为丰水地区水资源管理提供了全新的政策建议。     

Simultaneous semi-sequential testing of dual alternatives for pattern recognition

In this paper, we propose a new nonparametric simultaneous test for dual alternatives. Simultaneous tests for dual alternatives are used for pattern detection of arsenic contamination level in ground water. We consider two possible patterns, namely, monotone shift and an umbrella-type location alternative, as the dual alternatives. Pattern recognition problems of this nature are addressed in Bandyopadhyay et al. [5], stretching the idea of multiple hypotheses tests as in Benjamini and Hochberg [6]. In the present context, we develop an alternative approach based on contrasts that helps us to detect three underlying pattern much more efficiently. We illustrate the new methodology through a motivating example related to highly sensitive issue of arsenic contamination in ground water. We provide some Monte-Carlo studies related to the proposed technique and give a comparative study between different detection procedures. We also obtain some related asymptotic results.     

陈云与新中国的水利建设

陈云高度重视水利建设对于农业发展和国民经济恢复和增长的作用,强调兴修水利以防治水旱灾害、保障人民的生命财产安全,实现水资源的综合利用和开发。他还提出要节约、保护水资源,防止水资源的污染和破坏。陈云关于水利建设的思想,对于我们总结建国后中国共产党水利建设和水利事业发展的历史、更好地建设中国特色现代化水利具有重要意义。