Perceived changes in environmental degradation and loss of ecosystem services,and their implications in human well-being

ABSTRACT

Rural communities worldwide face a decrease of critical ecosystem services caused by replacement of native forests by commercial plantations. Replacement of native forest by commercial plantations decreases water provisioning, with possible negative impacts over well-being. We tested this hypothesis in Central Chile. We assessed subjective well-being (SWB) and local perceptions of changes in forest cover and water provision among 78 rural families. We also assessed if the Shifting Baseline Syndrome (SBS) affects the perceptions of environmental changes and their implications in SWB. Individuals perceived less forest cover than 20 years ago, and this is seen as a factor of decreased livelihood, availability of forest products, and water provisioning for households. People also reported less water available than 20 years ago. The main drivers associated with decreased water provision were the establishment of pine plantations (44% of individuals) and drought (44%). A better-off SWB was associated with perception of lower rate of deforestation. The perceptions of forest degradation and its association to SWB are affected by SBS. Paradoxically, a better-off SWB was also associated with an improvement of water quality, although the quantity and quality of water have decreased according to biophysical data, which ought to decrease the SWB. Impacts of environmental degradation in SWB are masked by factors such as more infrastructure for drinking water, assisted by governments. This masking of environmental degradation reduces the opportunity to avoid negative impacts over well-being among rural communities that are dependent on assistance around the world.     

风电场生命周期CO2排放核算与不确定性分析

提出了风力发电技术生命周期能耗和CO2排放核算的详细方法.应用上海某风电场数据进行核算,结果认为,风机生产阶段能耗和CO2排放占风电场生命周期能耗和CO2排放的比例均为最大,分别为68.23%和67.18%.不确定性分析认为,在所有强度参数中,钢生产综合能耗最为灵敏.风电场能耗强度和CO2强度分别为3.24gce/(kW?h)和9.47g/(kW?h),明显低于300MW火力发电机组的相同指标,分别为330gce/(kW?h)和915g/(kW?h). 20a服役期的50MW风电场满期后,同比300MW火电机组少排放CO2约234万t.     

基于时变可靠度分析的桥梁使用寿命预测

为分析一座桥梁结构寿命,在现有混凝土桥梁抗力和荷载的时变性研究的基础上,建立桥梁时变可靠度计算模型。将结构抗力等效转换为车辆荷载作用下结构所产生的竖向位移限值,预测远景交通量,反映荷载的时变性;运用非线性有限单元增量分析方法,以递增特定荷载的方式,采用响应面法计算时变可靠度指标及累计失效概率。结果表明:桥梁结构初始阶段具有足够大的可靠性,但其会随时间推移迅速衰减,利用韦伯分布函数和最小二乘法计算桥梁累计失效概率,进而推算桥梁使用寿命。根据桥梁寿命可靠度计算结果,制定出桥梁最佳维修养护策略。     

基于差错分类框架辨识人为差错

为解决人因可靠性分析中的人为差错辨识问题,提出新的工作流程。在该流程中,由人为差错引导词引导,以自问自答方式开展差错辨识工作。针对动作和决策2种差错类型,分别设计差错基本分类框架。其中,动作差错基本分类框架包括5个差错大类,10个差错小类;决策差错基本分类框架包括2个差错大类,10个差错小类。这些差错小类可作为差错辨识过程中的引导词。通过2个实例,演示这2个框架在差错辨识过程中的作用。演示结果表明,在人为差错引导词引导下开展差错辨识工作,更容易保证差错辨识结果的全面性和一致性。     

尾矿库运行期DADT循环管控技术

为提高尾矿库这一矿山重大危险源安全监管系统化水平,实现数字化安全监管,提出了全寿命周期DADT循环管控技术理论。这项技术首先需要整合管控对象的三维数字化测控成果与调研资料,建立全寿命周期“健康档案”,其次运用DADT循环管控方法,同时耦合相关专业技术,“诊断、分析、设计、治理”管控对象的安全特征要素,发现并解决安全隐患。结合尾矿库自身特点与测控成果,阐述了尾矿库全寿命周期DADT循环管控技术的运行流程。以白马尾矿库为例,在三维点云数据基础上建立实体模型,运用全寿命周期DADT循环管控技术,耦合调洪演算过程,结果表明,尾矿库在后期堆排过程中,库区会出现“封闭水域”,提前发现并科学解决了尾矿库排洪隐患。全寿命周期DADT循环管控技术的运用,克服了以往安全监管对管控对象安全状况系统性掌控的不足,有利于精确处理安全隐患,为数字化安全监管的实现提供了一种全新思路。     

城镇燃气管道动火作业安全评价

针对城镇燃气管道动火作业的高危险性,为保障生命财产安全,提出一种基于未确知测度的安全评价方法。首先,从动火施工作业的前、中、后3个阶段对整个作业过程进行安全分析,并基于作业的前阶段建立安全评价体系。然后,引入未确知测度模型,将因素的量化值与测度函数结合得出测度评价矩阵,采用变异系数法处理评价矩阵,确定各危害因素的客观权重。最后,根据测度评价矩阵与因素权重得出动火作业的安全等级,并对危害因素进行排序。实例结果表明:应用该方法能有效地确定出城镇燃气管道动火作业的安全等级,对于不安全的施工作业,可根据排序确定高危险因素,并采取措施降低其危险性,提高整个动火作业过程的安全性。     

金属矿山地表沉陷的可拓评价预警

针对金属矿山地表沉陷灾害的预警问题,应用可拓学理论,建立基于物元和关联函数的矿山沉陷评价预警模型。选取沉陷密度、沉陷面积率、断层密度、覆层强度指标、深厚比、下沉系数6个预警指标,划分4级预警模式。根据各指标特征建立关联函数并计算关联度,结合德尔菲-层次分析法确定指标权重。选取我国4个典型金属矿山开展模型验证,获得各矿山地表沉陷的预警等级,与矿山实际情况对比分析认为评价结果具有较好的可信度。该方法操作简单,结果直观,为金属矿山的地表沉陷预警提供了新的思路。     

基于环境风险的危险废物填埋场安全寿命周期评价

通过系统分析危险填埋场的设计功能,结合安全寿命周期的定义,对危险废物填埋场的安全寿命周期进行了定义.在此基础上,通过文献查阅和理论推导确定了描述危险废物填埋场主要单元性能衰减的老化模型,并结合课题组开发的渗漏环境风险分析模型,建立了危险废物填埋场的安全寿命评估模型,并选择中部某危险废物填埋场进行了案例研究.结果表明:随着防渗材料老化以及导排层淤堵,渗滤液渗漏量将逐渐增加,其安全贮存功能将逐渐丧失,并逐渐达到其安全寿命周期.仅就本案例而言,该填埋场的安全寿命周期为385a;对安全寿命周期相关参数的敏感性分析表明,浸出浓度与填埋场安全寿命周期呈负相关,包气带厚度和含水层厚度与安全寿命周期呈正相关,相关系数分别为-0.79、0.99和0.72,这说明包气带厚度对安全寿命周期影响更大,其次为浸出浓度,最后为含水层厚度;应加强填埋场相关单元老化模型研究,开展其他因素对填埋场安全寿命周期的影响,进一步完善危险废物填埋场安全寿命周期评价理论和方法.     

Accident prevention approach throughout process design life cycle

The accident rate in the chemical process industry (CPI) has not been decreasing although majority of accident causes have been identified and could have been prevented by using existing knowledge. These recurring accidents show that the existing knowledge has not been used effectively. In this paper, accident knowledge learned from earlier accident analyses are utilized to predict the common design errors during chemical plant design. An accident prevention approach throughout process design life cycle is proposed for a safer design consideration where designers are guided to identify common design errors, accident contributors and critical points to look for. The accident prevention approach has been applied to analyze the BP Texas City Refinery Explosion and Fire tragedy.     

湖南省绥宁县黄桑坪自然保护区珍稀濒危植物长苞铁杉自然种群年龄结构及生态对策

通过对湖南省绥宁县黄桑坪自然保护区长苞铁杉的种群结构、特定时间生命表、生殖价分析、分布数量与环境因子的关系进行分析.结果表明:(1)种群结构数量具有"中间大,两头小"的特点,为衰退型种群,虽然种群有一定的幼龄个体,但死亡率高,35 a内长苞铁杉的年龄结构模型为:Age(a)=0.002 765(DBH)3-0.128 756(DBH)2+4.120 978(DBH)+13.439 846(R=0.991 2,F=2 654.48);(2)长苞铁杉种群既有r对策特征,又有K对策特征,该种群处于r对策→K对策的过渡阶段;(3)长苞铁杉的累积剩余生殖价(SRRV)和整个生活史的总生殖价(TRV)呈现出逐渐递减的趋势,而生殖投资策略(OREx)在整个生长过程中具有"n"型变化特征,说明长苞铁杉种群有实现生殖与恢复的可能,但能力有限.