Signal-transfer modeling for regional assessment of forest responses to environmental changes in the southeastern United States

Stochastic transfer of information in a hierarchy of simulators is offered as a conceptual approach for assessing forest responses to changing climate and air quality across 13 southeastern states of the USA. This assessment approach combines geographic information system and Monte Carlo capabilities with several scales of computer modeling for southern pine species and eastern deciduous forests. Outputs, such as forest production, evapotranspiration and carbon pools, may be compared statistically for alternative equilibrium or transient scenarios providing a statistical basis for decision making in regional assessments. This revised version was published online in July 2006 with corrections to the Cover Date.     

基于灰色聚类方法的湖泊营养状态综合评价

将湖泊水体的营养状态看作一个灰色系统,建立用于识别湖泊营养状态属性的灰色聚类综合评价模型,将水质级别作为一个灰类,水质状态作为灰色变量,根据灰色白化权函数聚类方法来确定水体营养状况归类。以太湖为例,基于分布全湖的20个监测点数据,运用灰色聚类法对其进行富营养状态综合评价,结果表明,监测时段太湖大部分水体基本处于中营养水平,局部湖面达到中度富营养状态,客观地反映了太湖湖区水体营养状况。     

Simulation and evaluation on the eco-industrial system of Changchun economic and technological development zone, China

Reasonable structure, adaptive patterns and effective regulation of society, economy and environment subsystems should be taken into account in order to obtain harmonious development of urban eco-industrial system. We simulated and evaluated a redesigned eco-industrial system in Changchun Economic and Technological Development Zone (CCETDZ) in the present work using system dynamics and grey cluster methods. Four typical development strategies were simulated during 2005–2020 via standard system dynamic models. Furthermore, analytic hierarchy process and grey cluster allowed for the eco-industrial system evaluation and scenarios optimizing. Our dynamic simulation and statistical analysis revealed that: (1) CCETDZ would have different development scenarios under different strategies. The total population in scenario 2 grew most rapidly and reached 3.28 × 10⁵ in 2020, exceeding its long-term planning expected population. And the GDP differences among these four scenarios would amount to 6.41 × 10¹⁰ RMB. On the other hand, environmental pollution would become serious along with economy increasing. As a restriction factor, positive or negative increment of water resource will occur according to the selected strategy. (2) The fourth strategy would have the best efficiency, which means that the most efficiently development of CCETDZ required to take science, technology, environment progress and economy increase into account at the same time. (3) Positive environment protection measures, such as cleaner production, green manufacture, production life cycle management and environment friendly industries, should be attached great importance the same as economy development during 2005–2020 in CCETDZ.     

丹江口水库湖北库区水质分区及长期变化趋势

丹江口水库是南水北调中线工程水源地,准确地掌握丹江口水库水环境质量状况变化情况,对保障调水工程顺利进行有着极其重要的意义。基于水质理化指标将丹江口水库湖北库区水域划分为4个区,各分区的主要物理指标存在显著差异,化学指标较为均一;近10年水质历史监测数据显示,湖北库区除总氮指标外,其余监测指标水质类别均达到或优于Ⅱ类,总体水质保持优良;氨氮、总磷、总氮3项指标年均浓度从2007年起呈增加趋势,在2011年后均有所降低并趋于稳定。农业面源污染对丹江口水库水质影响较大。目前采取的各项环保措施对丹江口水库的水质产生了积极的影响,需继续加大各项治理措施的实施力度,完善水质监测系统,保障丹江口水库水质安全。     

Hydrochemical evaluation of the Voltaian system--the Afram Plains area, Ghana

Inverse geochemical modeling from PHREEQC, and multivariate statistical methods were jointly used to define the genetic origin of chemical parameters of groundwater from the Voltaian aquifers in the Afram Plains area. The study finds, from hierarchical cluster analysis that there are two main hydrochemical facies namely the calcium-sodium-chloride-bicarbonate waters and the magnesium-potassium-sulfate-nitrate waters in the northern and southern sections, respectively, of the Afram Plains area. This facies differentiation is confirmed by the distribution of the SO(4)(2-)/Cl(-) ratio, which associates groundwater from the northern and southern sections to areas influenced by contact with evaporites and seawater, respectively. Principal component analysis (PCA) with varimax rotation using the Kaiser criterion identifies four principal sources of variation in the hydrochemistry. Mineral saturation indices calculated from both major ions and trace elements, indicate saturation-supersaturation with respect to calcite, aragonite, k-mica, chlorite, rhodochrosite, kaolinite, sepiolite, and talc, and undersaturation with respect to albite, anorthite, and gypsum in the area. Inverse geochemical modeling along groundwater flowpaths indicates the dissolution of albite, anorthite and gypsum and the precipitation of kaolinite, k-mica, talc, and quartz. Both the PCA and inverse geochemical modeling identify the incongruent weathering of feldspars as the principal factors controlling the hydrochemistry in the Afram Plains area. General phase transfer equations have been developed to characterize the geochemical evolution of groundwater in the area. A very good relationship has been established between calcite and aragonite saturation indices in the Afram Plains area, with R(2)=1.00.     

聚类分析法在建筑施工事故统计数据分析中的应用

采用SPSS多元统计软件中的聚类分析法把我国大陆31个省(市、自治区)按建筑施工事故损失和经济水平划分为3类进行聚类分析,并对聚类结果做相关研究,结果表明:建筑施工事故损失与经济水平呈正相关,由此提出了一些建筑施工事故统计的建议.     

基于TCT的平面交叉口灰色聚类评价方法

交通冲突技术是一种非事故统计评价方法,是以大样本、快速、定量研究评价交通安全现状与改善效果的特点而异于传统的事故统计评价方法.应用交通冲突技术,引入交通冲突与混合当量交通量的比值(TC/MPCU)作为评价指标,提出对以时均交通冲突和交通量数据为依据的交叉口进行安全评价的交通冲突灰色聚类评价法.以某市5个相似交叉口的实测值加以验证.     

卧龙自然保护区土壤中有机氯农药的来源分析

为了判断清洁地区有机氯农药的来源,选择四川西部山区卧龙自然保护区高海拔点位的土壤样品,利用GC-HRMS方法测定有机氯农药的残留量. 卧龙土壤中w(HCHs)和w(DDTs)分别为(0.42±0.23)和(0.51±0.35) ng/g,比典型污染土壤低1～2个数量级. 利用聚类分析方法对浓度归一化数据进行分析,结果表明:卧龙土壤中HCHs的化学组成特征与典型污染土壤不同,而与典型大气样品相似;DDTs的组成特征在典型土壤和大气中没有稳定的显著差异. 结合有机氯农药的浓度水平、空间分布和物理化学性质进行分析,结果表明,大气传输过程的贡献可能是卧龙地区生态系统中HCHs以及其他有机氯农药的主要来源.      

清水河流域水质综合分析与评价

通过2018年4月、7月和11月在清水河流域布设32个采样点,监测F-、TN、TP等6项水质指标,应用单因子评价法、综合污染指数法、灰色关联法、模糊综合评价法对该河水质状况作综合评价,并分析F-是否参与评价时水质的变化情况.结果表明:当F-不参与水质评价时,清水河各月水质污染程度为7月>11月>4月;当F-参与水质评价...     

An improved grey wolf optimizer algorithm for identification and location of gas emission

Identification of the leakage of hazardous gases plays an important role in the environment protection, human health and safety of industry production. However, lots of current optimization algorithms, such as particle swarm optimization (PSO) and Grey Wolf Optimizer (GWO), suffer from poor global optimization capability and estimation accuracy. In this work, a hybrid differential evolutionary and GWO (DE-GWO) algorithm is proposed. Tested by simulation cases and Prairie Grass emission experimental data, DE-GWO shows higher estimation accuracy than GWO. Compared with the other four optimization algorithms, DE-GWO exhibits finer robust stability under different population sizes, fewer iterations, as well as higher estimation accuracy with fewer search agents. Importantly, simulation results demonstrate that DE-GWO is more suitable to apply in the scene with a small number of sensors. Therefore, the proposed in this paper outperforms other optimization algorithms for the gas emission inverse problem. DE-GWO can provide reliable estimation towards gas emission identification and positioning, which shows huge potential as the data analysis module of real-time monitoring and early warning system.