Prioritizing Agricultural Lands for Conservation Buffer Placement Using Multiple Criteria1

Qiu, Zeyuan, 2010. Prioritizing Agricultural Lands for Conservation Buffer Placement Using Multiple Criteria. Journal of the American Water Resources Association (JAWRA) 1-13. DOI: 10.1111/j.1752-1688.2010.00466.x Abstract: Although conservation buffers are multifunctional, the current conservation buffer planning strategies tend to use a single criterion, most frequently a hydrological or soil condition indicator, to guide conservation buffer placement. This study presents a watershed planning approach that prioritizes agricultural lands for conservation buffers based on multiple selection criteria and applies the approach to Raritan Basin in central New Jersey. The multiple selection criteria include soil erodibility, hydrological sensitivity, wildlife habitat, and impervious surface rate. These criteria capture the conservation buffers’ benefits in reducing soil erosion, controlling runoff generation, enhancing wildlife habitat, and mitigating stormwater impacts, respectively. An expert panel was used to identify and define the section criteria, review the measured values of those criteria, and develop the classification scales that assign the class score to each criterion. The prioritization is based on the summation of the criteria class scores. About one-third of agricultural lands are prioritized for conservation buffers in Raritan Basin. The total program cost of converting those prioritized agricultural lands to conservation buffers in Raritan Basin is estimated to be between $54.8 and 102.9 million depending on the composition of installed conservation buffer practices.     

农地资源不同价值属性的产权结构设计实证

农地是农业的基础、国民经济的基础,也是社会稳定的基础。农地资源具有经济价值属性、生态价值属性和社会价值属性,而社会价值属性包括社会保障功能价值、社会稳定功能价值及其他社会功能价值。本文针对农地资源不同的价值属性进行了产权结构设计,经济价值属性对应于农地农用产权,社会保障功能价值对应的是农地发展权,其他的价值属性构成了农地的公共产权。通过建立农地资源不同形态的价值属性与产权、价格之间的关系框架,为农地产权价格的衡量提供了依据。江都市的实证研究表明:农地发展权价格和公共产权价格在农地完全价格中的比重高达81.85%,其中,发展权价格的比重最大,达到63.02%,是农用产权价格的3.47倍;而公共产权价格的比重也达到18.83%,高出农用产权价格4%。在征地过程中如果考虑农地发展权和公共产权,并将其权益分配给农民,那么农民的土地财产权益可以增加4倍多。     

新的污染物环境危害评价指标——超标强度

污染物的危害程度不仅与超标率和超标倍数有关,而且与污染物超标持续时间有关。同样高的污染物浓度,如果其持续时间长短不同,其对环境的生态效应是不同的。为此,在充分分析超标率、超标倍数所存在缺陷的基础上,通过实例分析对比,以直观图解的方式提出了一套新的污染物环境危害评价指标体系——超标强度指标体系。超标强度指标体系中涉及的主要概念和指标有标准面积、超标面积、超标持续时间、超标强度和综合超标强度。在阐述了各指标的概念含义和计算方法后,以同一组监测数据为例,用超标率和超标倍数与超标强度指标进行了对比评价。结果表明,用超标强度及其指标体系可以科学、准确区分和评判超标率、超标倍数指标体系所不能区分和评判的真实存在的客观事实,而且非常精确地给出了污染物超标持续时间。超标强度指标所涵盖的内容比超标率和超标倍数更丰富,评价的结果更准确,所反映的生态环境质量状况更客观准确、科学真实。超标持续时间表明了污染物超标状态的持续时间。     

Do remediation experts have what it takes to explain empirical uncertainty?

Words matter in risk communication, and experts’ choice of words is critical when remediation risks are being explained to nonexperts. In risk communication studies, communication gaps between experts and nonexperts are investigated but there is lack of primary research. An Australian project addresses this shortcoming through research into communication about the risks of contaminated land remediation, and this paper provides some of its findings. Seventeen experts completed a questionnaire about the meaning of some scientific terms, and analysis found that they have capacity to improve communication through their selection and use of language. When experts undertake risk communication, the language they use may increase or reduce communication gaps. When the topic is uncertainty about health risks, communication gaps about the extent of uncertainty may reduce the effectiveness of social engagement, leading to unintended consequences such as cost overruns. This situation makes for a good case study since remediation is about benefit as well as risk, and communication about benefit, while desirable, may not always be achievable. The study suggests how to improve risk communication by exploring the accuracy, clarity, and depth of expert language. It identifies attributes of language that can bridge gaps in knowledge and understanding and characterizes them as integration mechanisms. These are defined as knowledge forms and mental processes that support cooperation between different epistemic communities to achieve mutually agreed outcomes. Two integration mechanisms are suggested. Bridging content addresses communication gaps through the selection of content (what knowledge is selected). Bridging process addresses communication gaps through the use of language (how knowledge is explained). Bridging content and bridging process can be expressed through cognitive and experiential platforms, or a blending of both, so whether words are positioned in the science‐based or mental model of risk communication, a utility value can be found in their quality, whether reflected by accuracy or the power to communicate meaning.     

修复 PAHs 复合污染体系的高效菌群构建及降解特性简

从污染环境分离和筛选得到了9株PAHs降解菌,以其为基本菌种,构建高效修复PAHs复合污染体系的菌群（D）。采用平板稀释涂布计数法对降解体系中菌群（D）的动态结构进行了解析,数据显示菌群内的微生物在降解过程中能相互协作,发挥稳定且高效的降解作用。实验进一步研究了菌群D对单一PAH和混合PAHs的降解特性,结果表明,无论对单一PAH还是混合PAHs,菌群D均具有较强的降解能力。当降解历时6 d,菌群D能使40 mg/L的单一PAH平均降解85.8%,使60 mg/L的混合PAHs平均去除89.4%。菌群D在多环芳烃复合污染体系的生物修复方面具有潜在的应用价值。     

多水源供水管网中铁释放规律

针对水源切换而引起的水质超标现象,开展了多水源联合供水条件下管网中铁释放规律的研究。分析了北方某城市2种水源(滦河水和长江水)的水质特点,利用实验模拟反应器分别研究了水源完全置换和供水分界线处水源混合区域的铁释放规律。结果表明,多水源供水管网的铁释放速率与水源水质密切相关,特别是水中含高浓度SO2-4和氯化物时会加快铁的释放。不同水源之间的频繁切换会破坏管垢表面的钝化层,使铁释放速率迅速变化,随后会有所缓解,但新的平衡的形成需要较长时间。供水分界线处的水源混合区域,由于水质的不断变化造成管垢表面很难形成稳定的钝化层,铁释放速率持续偏高,只有当长江水所占比例高达75%以上时才能得到抑制。     

优化布点的TOPSIS法研究

针对多目标系统的优化布点问题,尝试提出用改进的TOPSIS法研究水质环境监测点位的优化,并建立改进的TOPSIS法优化模型.实例分析表明,该方法充分利用了优化矩阵的信息,优选结果符合客观实际,可用于环境监测点位的优化布点.     

磁铁矿纳米颗粒与Pb~(2+)复合物对大鼠肾细胞的毒性研究

磁铁矿纳米颗粒(magnetite nanoparticles, MNPs)是一种环境友好型吸附剂,广泛应用于废水中Pb~(2+)的处理。目前,有不少关于MNPs毒性的研究,但对MNPs处理Pb~(2+)形成的复合物的毒性却鲜有报道,其复合毒性亟待深入研究。本文以大鼠肾细胞(NRK)作为细胞模型,系统研究不同Pb含量的MNPs-Pb复合物,以及相应浓度的MNPs和Pb~(2+),对大鼠肾细胞活性、细胞形态和密度的影响,考察细胞对纳米颗粒的摄取以及细胞凋亡的作用机制,评估MNPs-Pb的毒性效应。结果表明,在本实验浓度和暴露时间(12 h)条件下,Pb~(2+)能够显著抑制细胞活性,改变细胞形态,促进细胞凋亡,对细胞有显著的毒性效应,并且呈现剂量相关性;利用MNPs吸附水环境中Pb~(2+)形成的复合物MNPs-Pb对大鼠肾细胞没有显著的毒性作用(P<0.05),MNPs对Pb~(2+)的吸附可能是Pb~(2+)的细胞毒性降低的原因。     

Nutrient and Sediment Production,Watershed Characteristics,and Land Use in the Tahoe Basin,California‐Nevada1

Abstract: In efforts to control the degradation of water quality in Lake Tahoe, public agencies have monitored surface water discharge and concentrations of nitrogen, phosphorus, and suspended sediment in two separate sampling programs. The first program focuses on 20 watersheds varying in size from 162 to 14,000 ha, with continuous stream gaging and periodic sampling; the second focuses on small urbanized catchments, with automated sampling during runoff events. Using data from both programs, we addressed the questions (1) what are the fluxes and concentrations of nitrogen and phosphorus entering the lake from surface runoff; (2) how do the fluxes and concentrations vary in space and time; and (3) how are they related to land use and watershed characteristics? To answer these questions, we calculated discharge‐weighted average concentrations and annual fluxes and used multiple regression to relate those variable to a suite of GIS‐derived explanatory variables. The final selected regression models explain 47‐62% of the variance in constituent concentrations in the stormwater monitoring catchments, and 45‐72% of the variance in mean annual yields in the larger watersheds. The results emphasize the importance of impervious surface and residential density as factors in water quality degradation, and well‐developed soil as a factor in water quality maintenance.