基于改进CM的尾矿坝体变形4级预警阈值确定方法*

为改善我国尾矿库在线监测系统由于重建设、轻利用而导致的事故预警能力被制约的现状,以尾矿坝体变形速率监测指标为研究对象,通过引入改进云模型,根据3E规则确定尾矿坝变形监测的正常运营值边界,建立尾矿库坝体变形速率4级预警阈值确定模型,以湖北省某尾矿库为例进行实例分析。结果表明:通过提出的坝体预警阈值确定方法,可得出尾矿库坝体变形速率黄、橙、红各级预警阀值分别为10.842,16.68,25.02 mm/d;进一步与典型小概率法计算结果对比表明,所提出的尾矿坝变形速率4级预警阈值确定方法更加科学合理,可用于尾矿库重要安全监测指标预警值的确定。     

The perpetual state of emergency that sacrifices protected areas in a changing climate

A modern challenge for conservation biology is to assess the consequences of policies that adhere to assumptions of stationarity (e.g., historic norms) in an era of global environmental change. Such policies may result in unexpected and surprising levels of mitigation given future climate‐change trajectories, especially as agriculture looks to protected areas to buffer against production losses during periods of environmental extremes. We assessed the potential impact of climate‐change scenarios on the rates at which grasslands enrolled in the Conservation Reserve Program (CRP) are authorized for emergency harvesting (i.e., biomass removal) for agricultural use, which can occur when precipitation for the previous 4 months is below 40% of the normal or historical mean precipitation for that 4‐month period. We developed and analyzed scenarios under the condition that policy will continue to operate under assumptions of stationarity, thereby authorizing emergency biomass harvesting solely as a function of precipitation departure from historic norms. Model projections showed the historical likelihood of authorizing emergency biomass harvesting in any given year in the northern Great Plains was 33.28% based on long‐term weather records. Emergency biomass harvesting became the norm (>50% of years) in the scenario that reflected continued increases in emissions and a decrease in growing‐season precipitation, and areas in the Great Plains with higher historical mean annual rainfall were disproportionately affected and were subject to a greater increase in emergency biomass removal. Emergency biomass harvesting decreased only in the scenario with rapid reductions in emissions. Our scenario‐impact analysis indicated that biomass from lands enrolled in the CRP would be used primarily as a buffer for agriculture in an era of climatic change unless policy guidelines are adapted or climate‐change projections significantly depart from the current consensus.     

Setting conservation management thresholds using a novel participatory modeling approach

We devised a participatory modeling approach for setting management thresholds that show when management intervention is required to address undesirable ecosystem changes. This approach was designed to be used when management thresholds: must be set for environmental indicators in the face of multiple competing objectives; need to incorporate scientific understanding and value judgments; and will be set by participants with limited modeling experience. We applied our approach to a case study where management thresholds were set for a mat‐forming brown alga, Hormosira banksii, in a protected area management context. Participants, including management staff and scientists, were involved in a workshop to test the approach, and set management thresholds to address the threat of trampling by visitors to an intertidal rocky reef. The approach involved trading off the environmental objective, to maintain the condition of intertidal reef communities, with social and economic objectives to ensure management intervention was cost‐effective. Ecological scenarios, developed using scenario planning, were a key feature that provided the foundation for where to set management thresholds. The scenarios developed represented declines in percent cover of H. banksii that may occur under increased threatening processes. Participants defined 4 discrete management alternatives to address the threat of trampling and estimated the effect of these alternatives on the objectives under each ecological scenario. A weighted additive model was used to aggregate participants’ consequence estimates. Model outputs (decision scores) clearly expressed uncertainty, which can be considered by decision makers and used to inform where to set management thresholds. This approach encourages a proactive form of conservation, where management thresholds and associated actions are defined a priori for ecological indicators, rather than reacting to unexpected ecosystem changes in the future.     

恶臭污染评估指标体系研究

恶臭属于感觉公害,通常以人的嗅觉和主观感觉加以表征.因此,恶臭的评估指标和评估方法不同于其他环境污染.针对恶臭污染多组分、低浓度、污染源复杂等特点,建立适用于不同区域、不同污染特征的恶臭污染评估指标体系和评估指标分级标准.运用污染等级评估的模糊判别矩阵方法,构建恶臭污染评估模型.并以某工业园区为例进行实例分析,结果表明,该区域恶臭污染的综合评估等级为Ⅳ级(轻度污染),评估结果与实际污染状况相符.     

FY-2静止卫星监测雾的方法研究

云、雾与下垫面在可见光、中红外和长波红外波段的反射及辐射特性存在差异。FY-2静止卫星资料的时间分辨率高,有助于实时监测雾的形成与演变。根据雾在可见光及红外波段的反射和辐射特性,其与云、地表、水体等之间的差异,通过分析对比分别提取了日出前后雾的监测阈值和监测流程,并利用该方法对2007年12月19-20日华东、华北地区的一次大雾天气进行了监测,准确率达到76.6%。     

辽西北玉米不同生长阶段干旱灾害风险阈值的确定

以辽宁省西北6个市为研究区,选取玉米为研究对象,将其划分为播种期、苗期、拔节期、抽穗期和灌浆成熟期几个重要的生长阶段,综合气象与气候学、自然地理学、灾害科学、作物生态学和自然灾害风险科学等多学科的理论和方法,在充分考虑影响玉米干旱灾害动态风险的自然因素和人为因素的基础上,利用AHP、加权综合评价法、自然灾害指数法建立了玉米干旱灾害动态风险评价指标体系及模型;通过选取典型干旱案例年,运用最优分割理论在综合考虑玉米产量损失的基础上确定了玉米不同生长阶段的干旱灾害风险阈值,并用于玉米不同生长阶段干旱灾害风险值与玉米因旱减产损失的相关分析中。结果表明:辽西北地区玉米因旱减产损失与苗期干旱灾害风险值相关系数最大,玉米受苗期干旱灾害影响最严重;在灌浆成熟期相关性也较显著,受其影响也较大,这与辽西北地区春旱发生频率最高,伏旱时常发生的事实相符合。     

多米诺效应阈值研究进展

多米诺效应阈值是表征破坏效应相关物理参数的限值,是判断是否会引发多米诺效应的评判准则,是多米诺效应定量评价的开端。在对国内外多米诺效应研究成果分析的基础上,介绍了多米诺效应及其阈值,综述了引发多米诺事故扩张的三种物理效应阈值（即：热辐射阈值、超压阈值和碎片阈值）的研究现状。     

40种典型恶臭物质嗅阈值测定

结合国内外文献及对各恶臭排放单位的恶臭样品分析测试结果,选取包括硫化物、含氮化合物、苯系物、烯烃及含氧有机物在内的40种典型恶臭物质进行嗅阈值测试.按照我国恶臭污染嗅觉测试的标准方法——三点比较式臭袋法(GB/T 14675-93)对每种物质的嗅阈值进行了测定,得到了我国典型恶臭物质嗅阈值库,并对40种物质的嗅阈值(体积分数)范围进行了高、中、低区间划分,高阈值为10-1×10-6～10×10-6,中阈值为10-3×10-6～ 10-2×10-6,低阈值为10-5 × 10-6～ 10-4×10-6.分别对40种物质进行了气味品质描述,初步分析了恶臭物质分子结构与阈值的关系,不同类物质产生的气味品质有很大差异,苯系物主要呈现芳香气味,硫化物以硫化氢为代表产生臭鸡蛋气味,含氮化合物产生刺激的氨的气味,醛类和酯类以花香型或果香型气味为主,酸类以汗臭味为主.通过实例介绍了嗅阈值在恶臭污染控制中的应用,结果表明,在恶臭污染防治与控制中,选择有效去除阈稀释倍数最大的恶臭物质是一种重要的恶臭防治途径.     

3种烤烟中Cd分配累积规律及土壤Cd安全临界值的研究

为保证烤烟生产的安全,降低重金属对人体的毒害,对植烟土壤重金属安全临界值进行推算.通过土壤盆栽试验,研究了3个烤烟品种翠碧1号、K326和云烟87对Cd的累积和分配规律,土壤中Cd2+添加量分别为0、0.5 mg/kg、1 mg/kg、2 mg/kg、4 mg/kg、8 mg/kg,并采用回归分析方法计算了植烟土壤Cd的安全临界值.结果表明,烤烟Cd质量比受外源Cd添加量影响较大,下部叶Cd质量比总是高于其他部位.随Cd添加量增大,各部位Cd质量比上升且差别逐渐增大.Cd在土壤-根的转移系数较低,地上部各部位对土壤Cd转移系数的平均值表明,翠碧1号对Cd富集能力略强,而K326较弱.外源Cd的添加导致土壤-下部叶Cd的转移系数达最高,Cd在根-下部叶的转移系数明显高于其他部位间的转移系数,并使Cd在烤烟植株各部位间的转移系数呈先增后降的趋势.烤烟地上部的Cd累积量均高于根部,其中中、下部叶Cd累积量最多,而上部叶较少.经推算得出,烤烟叶片Cd的最高允许质量比为5.79 mg/kg,由烤烟中部叶Cd质量比与土壤有效Cd质量比的回归模型得到,3种烤烟的植烟土壤的安全临界值分别为0.17 mg/kg(翠碧1号)、0.19 mg/kg(K326)和0.15 mg/kg(云烟87),云烟87的土壤安全临界值可以作为制定福建烟区土壤Cd的安全临界值依据.     

废旧有机玻璃再生利用行业挥发性有机物(VOCs)排放特征研究

以浙江省湖州某镇的废旧有机玻璃裂解再生行业污染整治为例,通过选取4家具有代表性的废旧有机玻璃裂解再生企业,对其整治后排放的工艺废气和厂界空气中特征污染物浓度进行监测,分析其与国内外现有标准限值的符合性,并评估其厂界特征污染物产生的人体健康风险,为建立该行业地方污染物排放标准提供依据.结果表明,废旧有机玻璃再生行业排放废气成分主要为甲醇和甲基丙烯酸甲酯,且后者存在超标的情况;虽然厂界空气中的臭气浓度基本超过了现行的国家标准,但其特征污染物基本不会对人体健康产生较大的危害.另外,根据现有企业的实际情况,以较先进治理技术为依据,并参考国内外相关标准的基础上,建议该行业地方标准中甲醇、甲基丙烯酸甲酯及臭气浓度指标现有/新建(无组织)限值分别为45/30(0.5)mg·m-3、30/25(0.5)mg·m-3及1 000/800(20).