基于ISODATA法的三峡库区生态区划

在可持续发展思想的指导下,以生态学理论为基本依据,探讨了生态区划的原则、指标和方法。采用ISODATA法结合SPSS100中的层次聚类分析软件包,选择生态环境指标、社会发展指标和经济发展指标等20个定性、定量指标,利用数量化评分标准将三峡库区划分为4个生态类型区,并对各生态类型区的主要特征进行分析,应用ArcGIS绘制出三峡库区生态区划图,结果表明第I区生态类型较好。研究指出三峡地区生活在生态安全质量较高的人口约有28万多人,只占库区总人口的17%;此外通过对各区生态经济特征的综合评价结果,可以看出各区主要以山地、丘陵地为主,而且水土流失面积占60%左右,三峡库区生态安全形势十分严峻。旨在为生态分区评价以及三峡库区生态安全建设提供参考,提出加强山地丘陵的综合治理、控制水土流失及降低污染是优化三峡库区生态状况的关键。     

A review of adaptive cluster sampling: 1990–2003

Adaptive cluster sampling (ACS) is an adaptive sampling scheme which operates under the rule that when the observed value of an initially selected sampling unit satisfies some condition of interest, C, other additional units in some pre-defined accompanying neighborhood are also added to the sample. In turn, if any of these additional units satisfy C, then their corresponding unit neighborhoods are added to the sample as well, and so on. This process stops when no additional units satisfying C are encountered. This paper will provide a review of the major developments and issues in ACS since its introduction by Thompson (1990) [Journal of the American Statistical Association, 85, 1050–1059].     

Analytical evaluation of mesoscale fluxes and pressure field

Terrain in natural areas is never homogeneous: there may be a variety of vegetation types and patches of vegetated and unvegetated areas which can modify the mesoscale atmospheric flow. Moreover, horizontal thermal inhomogeneities in the planetary boundary layer are a well known source of mesoscale circulation systems such as land and sea breezes, mountain-valley winds, and urban heat island circulations. Since those phenomena are not resolved in regional scale numerical models, therefore an analytic procedure able to evaluate the relative importance of mesoscale and turbulent heat fluxes associated with surface thermal heterogeneities is of crucial importance in the optic of developing a parameterization of mesoscale effects generated by these heterogeneities for use in larger scale models. In the present paper we analyze how small a horizontal variation in surface heating can be and still produce a significant mesoscale circulation, how the heat and momentum fluxes associated to mesoscale flows can penetrate deeply into the mid-troposphere, and how they modify tropospheric relevant climate parameters, such as the atmospheric static stability. In addition, we evaluate the terms of the pressure gradient force, nonlinear and linear, non-hydrostatic and hydrostatic, as function of time and space scales of the mesoscale flow. The present paper is mainly a review of analytical results, the numerical comparison and verification using RAMS is in progress.     

Ward法在大气监测网络优化设计中的应用

在大气监测统计资料基础上,进行Ward法聚类分析,从而对宁波市的大气监测点进行优化,得到监测点位的最佳位置分布,通过检验,证明其技术路线是可行的.     

Modeling of oak pollen dispersal on the landscape level with a mesoscale atmospheric model

We present the extension and application of the mesoscale atmospheric meteorology model METRAS for dispersion of oak pollen. We incorporated functions for pollen emission, pollen viability and pollen deposition into METRAS and simulated pollen dispersal on a scale of up to 200 km. The basis of the simulations is a real landscape structure that includes topography, land use, and the location and size of oak stands. We simulated the oak pollen dispersion of one single oak stand with an estimated annual pollen production of 1 billion pollen grains/m² forest surface on two exemplary days of the flowering season in 2000. Depending on the meteorological situation of the simulated days, a pollen cloud with about 10 pollen/m³ may extend up to 30 km from the source. Downstream of the oak stand, approximately 1,000 pollen/m² deposited up to a distance of 25 km, and lower amounts of pollen deposited up to 100 km away. These values of pollen concentration and deposition lay within the range of published field studies. Overall, it is shown that mesoscale atmospheric models are applicable to simulate pollen dispersal on the landscape level.     

文山城空气质量监测点位优化研究

用网格实测法对文山城空气质量监测点位进行优化研究,全城共均匀布设12个网格点,2002年4月,连续20d监测了各点大气中SO2、NO2和TSP的浓度,运用模糊聚类法对监测数据进行分析,并综合城市规划、人口分布、污染特征等因素,优选出足以反映文山城空气质量状况的3个最佳监测点.经检验,优选点位的代表性较好,结果满意.     

河台韧性剪切带金矿床三维空间金及伴生微量元素地球化学特征及矿床深部评价

韧性剪切带金矿床不少已由勘探转入开采 ,当前生产上急待解决的问题是矿床深部矿体延深评价。笔者对河台金矿床矿山资料进行第二次开发 ,在矿床三维空间进行系统取样分析 ,以研究河台金矿床Au与伴生微量元素在纵向及横向上的地球化学行为。本文拟运用元素含量、元素比值、元素共生组合相关分析等对河台金矿床矿体延深进行评价     

云下洗脱-Eulerian模式

在Eulerian模式中,在大气氨浓度大于硝酸的条件下,简要讨论了各种污染物对雨水组成的影响.结果表明,在本文考虑的情况下,氨对SO_2气体洗脱和SO~(2-)形成的影响最大,且能抑制雨水的酸化;过氧化氢的作用略小于氨.气溶胶对雨水SO_4~(2-)浓度的贡献小于气体.云下H_2O_2和O_3氧化能力的大小取决于雨水的pH、降落距离和各自的浓度.在雨水pH高,降落距离短和各自浓度小时,O_3的氧化能力大于H_2O_2,反之则H_2O_2大于O_3.对韶关降水酸化的模拟表明,考虑气体污染物补充机制的Eulerian模式可以较好地模拟现场降水酸化过程.     

张家口地区排污工业企业集聚与水污染空间耦合特征

基于排污企业污染源环境统计数据,应用水污染物排放强度和核密度分析等方法,研究张家口地区排污工业企业的空间集聚特征及其与水污染排放空间之间的空间耦合特征,结果显示：（1）张家口地区工业企业空间集聚程度存在一定的空间异质性,崇礼县、赤城县整体上几乎无污染密集型企业分布。污染密集型企业主要沿洋河流域分布。（2）农副食品加工业、黑色金属冶炼及压延加工业、食品制造业、煤炭开采和选洗业这四大行业的COD、NH₃-N、总氮等水体污染物排放量相对最大。（3）工业企业集聚度与水环境污染程度的空间正向耦合效应明显,96.23%的区域呈较强正向耦合特征。高集聚—污染高值区占比0.40%。针对四种空间耦合状态提出未来污染物排放管控方向,以期为政府部门准确锁定治理区提供决策依据。     

绥化市一次空气污染过程及潜在源区分析

本研究以2019年12月21—25日绥化市一次严重的空气污染事件为研究对象,分析了此次污染概况、气象条件、污染成因以及污染的潜在源区.结果表明：此次污染期间,绥化市以PM_2.5污染为主,污染特征由21日10：00及22日11：00的偏燃煤污染型转变为24日15：00的偏二次颗粒物污染型,最终25日12：00污染特征又转变为偏燃煤型,本次污染主要以燃煤、机动车尾气和二次无机源为主;不利的气象条件主要由于弱风、高湿及低温、较差的扩散条件导致污染物局地积累;48 h后向轨迹模拟表明污染期间绥化市受4类气流输送的影响,主要来源于俄罗斯、内蒙古、吉林等方向,其中超标轨迹占97.4%;WPSCF分析发现潜在源区主要集中在绥化本地中部、辽宁省东北部、大庆市中部、齐齐哈尔市东南部、哈尔滨市中部区域;WCWT模拟出的潜在源区域较WPSCF大,模拟发现吉林北部对绥化PM_2.5污染贡献值为60~80 μg·m^-3,黑河东北部的贡献值高达100 μg·m^-3以上,俄罗斯、内蒙古地区对绥化市大气PM_2.5污染水平的影响及贡献较小.