基于区间活性数据的定量结构-活性关系

利用贝叶斯统计方法构建了基于区间活性数据的取代苯胺和苯酚类化合物对大型溞(Daphniamagna)24 h急性毒性的定量结构-活性关系模型,并与基于平均数和中位数的点估计活性数据的定量结构-活性关系模型进行了比较.结果表明,前者可以充分利用化合物的活性数据信息,模型具有更好的拟合效果与预测能力以及较宽的应用范围.基于区间活性数据的定量结构-活性关系模型可为生态风险评价等提供更加可靠的预测数据.     

2007-2011年我国烟花爆竹事故统计分析研究

燃放烟花爆竹的习俗由于其在中国民俗中的特殊含义而延续至今,但是,因其自身的易燃、易爆性,烟花爆竹生产具有很高的风险性和危害性,引发的各类安全事故时有发生,不仅对社会财产造成严重损失,更危害到人民的生命安全。依据不同分类方法对2007—2011年间我国烟花爆竹事故进行了综合统计分析,得出了事故总体情况,不同方法统计下的事故比例,以及事故原因分类等,并进一步基于原因分析,从法律法规、技术手段以及安全管理三方面提出了一系列相关措施建议。     

Comparison between linear and non-linear forms of pseudo-first-order and pseudo-second-order adsorption kinetic models for the removal of methylene blue by activated carbon

The best-fit equations of linear and non-linear forms of the two widely used kinetic models, namely pseudo-first-order and pseudo-second-order equations, were compared in this study. The experimental kinetics of methylene blue adsorption on activated carbon was used for this research. Both the correlation coefficient (R ²) and the normalized standard deviation Δq(%) were employed as error analysis methods to determine the best-fitting equations. The results show that the non-linear forms of pseudo-first-order and pseudo-second-order models were more suitable than the linear forms for fitting the experimental data. The experimental kinetics may have been distorted by linearization of the linear kinetic equations, and thus, the non-linear forms of kinetic equations should be primarily used to obtain the adsorption parameters. In addition, the Δq(%) method for error analysis may be better to determine the best-fitting model in this case.     

Nutrient criteria for lakes,ponds, and reservoirs: A Bayesian TREED model approach

We develop regional-scale eutrophication models for lakes, ponds, and reservoirs to investigate the link between nutrients and chlorophyll-a. The Bayesian TREED (BTREED) model approach allows association of multiple environmental stressors with biological responses, and quantification of uncertainty sources in the empirical water quality model. Nutrient data for lakes, ponds, and reservoirs across the United States were obtained from the Environmental Protection Agency (EPA) National Nutrient Criteria Database. The nutrient data consist of measurements for both stressor variables (such as total nitrogen and total phosphorus), and response variables (such as chlorophyll-a), used in the BTREED model. Markov chain Monte Carlo (McMC) posterior exploration guides a stochastic search through a rich suite of candidate trees toward models that better fit the data. The Bayes factor provides a goodness of fit criterion for comparison of resultant models. We randomly split the data into training and test sets; the training data were used in model estimation, and the test data were used to evaluate out-of-sample predictive performance of the model. An average relative efficiency of 1.02 between the training and test data for the four highest log-likelihood models suggests good out-of-sample predictive performance. Reduced model uncertainty relative to over-parameterized alternative models makes the BTREED models useful for nutrient criteria development, providing the link between nutrient stressors and meaningful eutrophication response.     

Quantifying Eradication Success: the Removal of Feral Pigs from Santa Cruz Island, California

Abstract:  A major challenge facing pest-eradication efforts is determining when eradication has been achieved. When the pest can no longer be detected, managers have to decide whether the pest has actually been eliminated and hence to decide when to terminate the eradication program. For most eradication programs, this decision entails considerable risk and is the largest single issue facing managers of such programs. We addressed this issue for an eradication program of feral pigs ( Sus scrofa ) from Santa Cruz Island, California. Using a Bayesian approach, we estimated the degree of confidence in the success of the eradication program at the point when monitoring failed to detect any more pigs. Catch-effort modeling of the hunting effort required to dispatch pigs during the eradication program was used to determine the relationship between detection probability and searching effort for different hunting methods. We then used these relationships to estimate the amount of monitoring effort required to declare eradication successful with criteria that either set a threshold for the probability that pigs remained undetected (type I error) or minimized the net expected costs of the eradication program (cost of type I and II errors). For aerial and ground-based monitoring techniques, the amount of search effort required to declare eradication successful on the basis of either criterion was highly dependent on the prior belief in the success of the program unless monitoring intensities exceeded 30 km of searching effort per square kilometer of search area for aerial monitoring and, equivalently, 38 km for ground monitoring. Calculation of these criteria to gauge the success of eradication should form an essential component of any eradication program as it allows for a transparent assessment of the risks inherent in the decision to terminate the program.     

浅论"三表合一"的设想

对国家环保总局提出的"三表合一"的设想,从三个方面提出自己的观点。第一,应以排污申报登记核定为基础,客观建立污染源动态数据库;第二,"三表合一"应该是环境统计报表、排污收费报表、污染控制报表等各方面污染源的数据统一到排污申报登记报表;第三,"三表合一"首先应建立统一的污染源指标体系,统一的污染测算方法和统一的基础数据库。     

A HYDROCLIMATIC APPLICATION STRATEGY FOR THE POISSON PARTIAL DURATION MODEL1

ABSTRACT: A strategy for formulating and testing the Poisson partial duration extreme value model is presented. The procedure is demonstrated using recorded Streamflow series from a humid subtropical region of the southern United States. The observed data series are partitioned by climatic causes and tested for both the Poisson assumption and the validity of the exponential as marginal distributions. Several statistical tests are utilized in making these determinations. Some important aspects of the model as applied to humid climates are demonstrated. It was found that a majority of Streamflow series could be represented by the model and that significant differences do exist between the arrival structures of floods resulting from different climatic mechanisms. However, these differences generally do not exist in the distribution of the flood magnitudes. In addition, it is possible that model validity is restricted by drainage basin size.     

Estimating net primary production and annual plant carbon inputs, and modelling future changes in soil carbon stocks in arable farmlands of northern Japan

Soil C sequestration in croplands is deemed to be one of the most promising greenhouse gas mitigation options for Japan's agriculture. In this context, changes in soil C stocks in northern Japan's arable farming area over the period of 1971-2010, specifically in the region's typical Andosol (volcanic ash-derived) and non-Andosol soils, were simulated using soil-type-specific versions of the Rothamsted carbon model (RothC). The models were then used to predict the effects, over the period of 2011-2050, of three potential management scenarios: (i) baseline: maintenance of present crop residue returns and green manure crops, as well as composted cattle manure C inputs (24-34 Mg ha⁻¹ yr⁻¹ applied on 3-55% of arable land according to crop), (ii) cattle manure: all arable fields receive 20 Mg ha⁻¹ yr⁻¹ of composted cattle manure, increased C inputs from crop residues and present C inputs from green manure are assumed, and (iii) minimum input: all above-ground crop residues removed, no green manure crop, no cattle manure applied. Above- and below-ground residue biomass C inputs contributed by 8 major crops, and oats employed as a green manure crop, were drawn from yield statistics recorded at the township level and crop-specific allometric relationships (e.g. ratio of above-ground residue biomass to harvested biomass on a dry weight basis). Estimated crop net primary production (NPP) ranged from 1.60 Mg C ha⁻¹ yr⁻¹ for adzuki bean to 8.75 Mg C ha⁻¹ yr⁻¹ for silage corn. For the whole region (143 × 10³ ha), overall NPP was estimated at 952 ± 60 Gg C yr⁻¹ (6.66 ± 0.42 Mg C ha⁻¹ yr⁻¹). Plant C inputs to the soil also varied widely amongst the crops, ranging from 0.50 Mg C ha⁻¹ yr⁻¹ for potato to 3.26 Mg C ha⁻¹ yr⁻¹ for winter wheat. Annual plant C inputs to the soil were estimated at 360 ± 45 Gg C yr⁻¹ (2.52 ± 0.32 Mg C ha⁻¹ yr⁻¹), representing 38% of the cropland NPP. The RothC simulations suggest that the region's soil C stock (0-30 cm horizon), across all soils, has decreased from 13.96 Tg C (107.5 Mg C ha⁻¹ yr⁻¹) in 1970 to 12.46 Tg C (96.0 Mg C ha⁻¹ yr⁻¹) in 2010. For the baseline, cattle manure and minimum input scenarios, soil C stocks of 12.13, 13.27 and 9.82 Tg C, respectively, were projected for 2050. Over the period of 2011-2050, compared to the baseline scenario, soil C was sequestered (+0.219 Mg C ha⁻¹ yr⁻¹) by enhanced cattle manure application, but was lost (−0.445 Mg C ha⁻¹ yr⁻¹) under the minimum input scenario. The effect of variations of input data (monthly mean temperature, monthly precipitation, plant C inputs and cattle manure C inputs) on the uncertainty of model outputs for each scenario was assessed using a Monte Carlo approach. Taking into account the uncertainty (standard deviation as % of the mean) for the model's outputs for 2050 (5.1-6.1%), it is clear that the minimum input scenario would lead to a rapid decrease in soil C stocks for arable farmlands in northern Japan.     

基于ArcGIS区统计的延安市土地生态敏感性评价

在对延安市土地生态环境问题进行调查研究的基础上,采用基于ArcGIS区统计方法进行土地生态敏感性评价,并首次采用了客观确权法--变异系数法确定评价因子权重,与以往叠加评价方法相比,在评价思路、确权方法、评价单元和叠加方法上都有不同程度改进,评价结果更加准确、客观、实用。土地生态敏感性评价结果显示,极敏感和高敏感区占到了全市总面积的40.11%,不敏感和低敏感区占全市总面积的52.06%,地域分异规律上,敏感性程度由北向南逐渐递减,并进行了土地利用生态敏感性评价。最后,针对不同土地生态敏感性分区因地制宜提出用地策略,为本轮土地利用总体规划修编和指导今后土地科学利用服务。     

全国环境统计数据审核软件设计与实现

依托《环境统计数据审核细则》(送审稿)等相关规定,以十一五环境统计软件数据审核功能为基础,设计环境数据访问接口,划分数据审核功能模块,建设环境统计数据审核软件,为确保环境统计数据质量提供信息化手段,减少人工审核的难度,提高工作效率。