基于改进遗传算法的河流水污染源反演方法

针对河流水污染应急响应过程中污染源排放历史迟知、未知的问题,结合多种群遗传算法和自适应遗传算法,利用一维河流水质模型和水质监测数据,研究建立了基于改进遗传算法的河流水污染定量源反演方法,实现了对河流污染源排放历史的识别与重构.将该方法应用于美国特拉基河流的3个不同流量下的示踪剂实验中,对示踪剂排放历史进行定量源反演分析.结果表明：IGA算法对高、中、低不同流量下的3次示踪剂实验均可以很好的重构和识别示踪剂排放历史,对于实际河流水污染源反演分析的误差均在可接受范围内.IGA算法在河流水污染源反演分析中具有一定的可靠性和稳定性,可为河流水污染精准溯源与治理提供科学的技术支撑.     

基于模糊物元模型的西苕溪流域生态系统健康评价

本文借助RS/GIS技术,结合遥感影像数据、环境监测数据和社会经济数据,运用模糊物元模型,从水域、水陆交错带和陆域子系统选取21项评价指标,建立了流域生态系统健康综合评价指标体系,对西苕溪流域生态系统健康状况的空间分布规律和限制性因子进行了探讨.研究结果表明,西苕溪流域生态系统健康整体呈现出优良状态,其中,生态系统健康优秀地区面积占68.2%,良好地区面积占31.8%,能够正常发挥流域服务功能,维持生态系统可持续发展.西苕溪流域生态系统健康在空间分布上呈现出上游好、下游差的局面.在各子系统健康评价中,水域生态系统优于陆域生态系统,水陆交错带生态系统最差.底栖动物完整性遭受破坏、湿地退化、人为干扰活动、水源涵养功能减弱、点源和面源污染负荷较重是限制西苕溪流域部分评价单元生态系统健康的重要因素.     

基于非参数核密度估计模型的尾矿库事故后沉积物中Pb和Hg的水生生物风险评估

汞(Hg)和铅(Pb)是2种典型的重金属污染物,对水生生态系统具有较强的毒害作用,是环境管理的重要指标。2015年11月的陇星锑业尾矿库泄露事件,造成嘉陵江流域约346 km长河段受到重金属污染,尾矿砂中高含量Hg和Pb主要归宿在污染团经过的河道沉积物中,引起的嘉陵江流域生态风险尚未被全面评估。为解决沉积物中污染物对水生生物的毒性效应数据较少的问题,采用相平衡分配法,利用大量的水生生物毒理试验数据,将其转化为相应的沉积物毒性效应数据;采用基于非参数核密度估计的物种敏感度分布(SSD)法,对嘉陵江沉积物中2种重金属(Hg和Pb)进行生态风险评价,并与其他分布模型(Normal、Logistic和Weibull)进行对比。结果表明:Hg的非参数核密度估计模型的K-S检验统计量、均方根误差(RMSE)和误差平方和(SSE)分别为0.111 1、0.025 04和0.000 627,相较其他分布模型为最小;Pb的非参数核密度估计模型的K-S检验统计量为0.125 0,相较其他分布模型为最小,RMSE和SSE分别为0.028 42和0.000 807,为较优。非参数核密度估计模型对2种重金属毒性数据有很好的适应性,可获得较优的模拟效果。嘉陵江流域15个采样点沉积物中Pb浓度显著高于Hg,但沉积物中Hg的生态风险水平远高于Pb。     

Using empirical models of species colonization under multiple threatening processes to identify complementary threat‐mitigation strategies

Approaches to prioritize conservation actions are gaining popularity. However, limited empirical evidence exists on which species might benefit most from threat mitigation and on what combination of threats, if mitigated simultaneously, would result in the best outcomes for biodiversity. We devised a way to prioritize threat mitigation at a regional scale with empirical evidence based on predicted changes to population dynamics—information that is lacking in most threat‐management prioritization frameworks that rely on expert elicitation. We used dynamic occupancy models to investigate the effects of multiple threats (tree cover, grazing, and presence of an hyperaggressive competitor, the Noisy Miner (Manorina melanocephala) on bird‐population dynamics in an endangered woodland community in southeastern Australia. The 3 threatening processes had different effects on different species. We used predicted patch‐colonization probabilities to estimate the benefit to each species of removing one or more threats. We then determined the complementary set of threat‐mitigation strategies that maximized colonization of all species while ensuring that redundant actions with little benefit were avoided. The single action that resulted in the highest colonization was increasing tree cover, which increased patch colonization by 5% and 11% on average across all species and for declining species, respectively. Combining Noisy Miner control with increasing tree cover increased species colonization by 10% and 19% on average for all species and for declining species respectively, and was a higher priority than changing grazing regimes. Guidance for prioritizing threat mitigation is critical in the face of cumulative threatening processes. By incorporating population dynamics in prioritization of threat management, our approach helps ensure funding is not wasted on ineffective management programs that target the wrong threats or species.     

The Value of Using Feasibility Models in Systematic Conservation Planning to Predict Landholder Management Uptake

Understanding the social dimensions of conservation opportunity is crucial for conservation planning in multiple‐use landscapes. However, factors that influence the feasibility of implementing conservation actions, such as the history of landscape management, and landholders’ willingness to engage are often difficult or time consuming to quantify and rarely incorporated into planning. We examined how conservation agencies could reduce costs of acquiring such data by developing predictive models of management feasibility parameterized with social and biophysical factors likely to influence landholders’ decisions to engage in management. To test the utility of our best‐supported model, we developed 4 alternative investment scenarios based on different input data for conservation planning: social data only; biological data only; potential conservation opportunity derived from modeled feasibility that incurs no social data collection costs; and existing conservation opportunity derived from feasibility data that incurred collection costs. Using spatially explicit information on biodiversity values, feasibility, and management costs, we prioritized locations in southwest Australia to control an invasive predator that is detrimental to both agriculture and natural ecosystems: the red fox (Vulpes vulpes). When social data collection costs were moderate to high, the most cost‐effective investment scenario resulted from a predictive model of feasibility. Combining empirical feasibility data with biological data was more cost‐effective for prioritizing management when social data collection costs were low (<4% of the total budget). Calls for more data to inform conservation planning should take into account the costs and benefits of collecting and using social data to ensure that limited funding for conservation is spent in the most cost‐efficient and effective manner.     

我国城镇化进程中碳排放影响因素的实证研究

利用1980—2013年间的城镇人口与碳排放数据,选取城镇化进程中影响碳排放的城镇化水平、城镇建设用地面积、第三产业增加值、人均可支配收入、城镇人均绿化面积等因素,实证分析了城镇化对我国碳排放的影响程度,并利用格兰杰夫因果关系与误差修正模型分析了二者的因果关系与时间效应。最后,从降低工业碳排放、加快低碳城镇化试点建设、推进低碳社区发展,促进新能源发展等方面提出了相关建议。     

兰州市废旧手机产生量预测分析研究

手机普及率日益提高,随之产生的废弃量也日益增多,分别采用时间梯度模型、市场供给A模型、斯坦福(stanford)模型对兰州市2013年-2022年废旧手机的产生量进行了预测.结果显示,不同模型预测结果之间存在较大差异,市场供给A模型和斯坦福(Stanford)模型的预测结果比较接近,均大于时间梯度模型的预测结果,三种模型预测的兰州市2022年废旧手机的产生量分别为40.40万、46.67万和21.04万部.总体上看,兰州市废旧手机的产生量增长趋势较快.     

短波长X射线衍射技术及在环境工程中的应用展望

介绍了短波长特征X射线衍射无损检测分析原理和方法,无损地测定了预拉伸铝板、高强钢孔挤压件、铝合金搅拌摩擦焊接件等材料部件的内部残余应力、内部物相、内部织构及其分布,并分析讨论了测试结果。该仪器具有体积小,投资少、使用维护方便等优势,展望了该无损检测分析技术在装备环境工程中的应用前景。     

ABC算法优化SVR的磨损故障预测模型

目的为了提高故障预测的精度,针对支持向量回归SVR(Support vector machine for regression,SVR)参数选择困难的问题,提出一种采用人工蜂群(artificial bee colony,ABC)算法优化支持向量回归(SVR)的故障预测模型(ABC-SVR)。方法该模型先对样本数据进行重构,然后将故障预测误差(适应度)作为优化目标,通过ABC算法寻优找到最优的SVR参数,建立故障预测模型。最后通过实例仿真验证模型的优越性。结果采用ABC算法优化的SVR故障预测模型进行时间序列预测,能够较好地跟踪发动机滑油金属元素浓度的变化过程,并且能够提前2个取样时间预测异常情况的出现。结论 ABC-SVR模型有效解决了SVR参数选择难题,能够更加准确地表现故障变化规律,提高了故障预测精度。     

厌氧-准好氧联合型生物反应器填埋场产气规律的研究

通过将厌氧型生物反应器填埋场（ANBL）和准好氧矿化垃圾生物反应床（SAARB）串联,组成新型的厌氧-准好氧联合型生物反应器填埋场（AN-SABL）,研究其产气速率、产气量以及产气组分的变化规律,以期为填埋气体的收集、利用和处理提供理论依据.实验表明,AN-SABL中的厌氧填埋单元的产气受到了抑制,其中ANBL2号单元和ANBL3号单元的产气率分别为49 L.kg-1和39 L.kg-1,仅占ANBL1号的94.2%和75.0%,但提高回灌频率,能促进厌氧填埋单元的产气,其甲烷含量最大值可达到62.67%;ANBL夏季产气速率和产气量明显高于冬季,并以12 h为周期交替出现产气高峰;此外,AN-SABL能够促进其厌氧单元的硝化和反硝化作用,N2O的含量受季节和填埋场类型影响显著,其变化范围在0.001 7%～4.017 9%之间.ANBL的累积产气量在初始调整阶段呈对数增长,过渡酸化阶段呈线性增长,酸化产甲烷阶段呈指数增长.