MM5-SMOKE-CMAQ as a modeling tool for 8-h ozone regulatory enforcement: application to the state of Arizona

The Penn State/NCAR Mesoscale Meteorological Model 5 (MM5), Sparse Matrix Operator Kernal Emissions (SMOKE), and Community Multiscale Air Quality (CMAQ) modeling systems were employed to simulate ozone concentration distribution within the State of Arizona, in particular, Phoenix air basin, as supporting information to designate nonattainment areas of the U.S. Environmental Protection Agency's new 8-h ozone standard. In general, based on statistical comparisons between predictions and available (sparsely distributed) observations, the modeling system performed reasonably well for the Phoenix basin, thus proving it to be a useful tool for both regulatory as well as research applications. Detailed inspection, however, revealed a serious problem with respect to the details of the ozone distribution in that for some days the transition from downslope flow to upslope flow in the Phoenix basin was delayed in the model, causing the ozone distribution to show an unrealistic high-ozone bias toward the west valley. Implementation of a modified subgrid parameterization improved the time of transition, and hence the prediction of ozone and its precursor distributions. This study points to possible inadequacies of commonly used subgrid parameterizations in dealing with rapidly changing flow conditions such as morning (and evening) transitions.     

基于风险熵的化工园区事故风险突变模型研究

为准确判断化工园区事故风险演化进程,基于风险熵理论分析化工园区系统风险状态,从影响园区系统风险熵的不同因素出发,根据化工园区公共区域和企业端的各自特点建立风险熵指标;利用尖点突变理论,用矩阵表征多参数多时刻的风险熵增和熵减值,建立化工园区熵增、熵减计算模型;根据计算结果判断事故风险状态。将所提出的方法应用于某化工园区,结果表明:在该园区某危化品储存企业丁二烯泄漏情况下园区系统风险熵发生突变,由泄漏引发二次事故的风险骤升,需要采取相应安全措施。分析结果与实际情况相符合。     

Using an individual-based model to quantify scale transition in demographic rate functions: Deaths in a coral reef fish

Scientifically informed population management requires quantitatively accurate demographic rate functions that apply at the spatial scale at which populations are actually managed, but practical constraints confine most field measurements of such functions to small study plots. This paper employs an individual-based population growth model to extrapolate the death rate function in a well-studied coral reef fish, the bridled goby Coryphopterus glaucofraenum, from the scale of coral reef “cells” at which it was measured to the larger scale of an entire coral reef. Density dependence in the whole-reef function actually proves stronger than in the local function because high goby density occasionally arises in local patches with few refuges from predators, producing very high mortality there. This IBM-based approach extends the reach of scale transition theory by examining considerably more realistic models than standard analytical methods can presently handle.     

Fragmentation profiles for real and simulated landscapes

When a natural landscape is represented by a series of categorical raster maps of varying resolution, a multiresolution characterization of spatial pattern can be obtained in which entropy is computed at each resolution conditional on the next coarser resolution. The series of entropy values is plotted as a function of resolution, resulting in a multiresolution profile of fragmentation pattern in the landscape. If a categorical raster map is available at a single resolution only, a series of degraded maps at increasingly coarser resolutions is generated and the fragmentation profile is computed for this series. An algorithm has been developed for obtaining the profile directly from the single resolution map without having to generate and store the coarser resolution maps. A hierarchical stochastic model is described for simulating categorical raster maps and the fragmentation profile of the generating process is obtained in terms of the model parameters. These process profiles provide benchmarks for assessing empirical profiles obtained from raster maps of actual landscapes. Methods of the paper are applied to several watersheds of Pennsylvania using landcover maps derived from satellite imagery. These examples indicate that characteristic landscape types induce characteristic features in their fragmentation profiles.     

试论我国生态型城镇的创建

介绍了我国生态型城镇创建的现状及存在问题，从生态经济系统、生态社会系统、生态环境系统、生态基础设施系统方面介绍了生态型城镇创建的重点领域，并从机构保障、法律保障、资金保障、人才保障方面提出了生态城镇创建的保障措施。     

Reactive shock and detonation propagation in U-bend tubes

The objective of the research outlined in this paper was to provide new experimental and computational data on initiation, propagation, and stability of gaseous stoichiometric propane–air detonations in tubes with U-bends. Extensive experimental and computational studies with the tube 51 mm in diameter with U-bends of two curvatures and two different shock-wave generators were performed. Numerical simulations of the process were used to reveal the salient features of the accompanying phenomena.     

生态建设中城镇生活污水集中处理问题探讨——以江苏省南通市为例

城镇生活污水难以集中处理是目前我国各地生态创建过程中的一个瓶颈问题。本文通过对南通市城镇生活污水处理现状和主要存在问题进行详细地分析,提出以生态市创建为依托,市镇村三级政府共同重视,合理规划,采取乡镇自建、以企带镇、以园带镇、镇镇联合等的建设模式,采用BOT、TOT等的新型融资和管理模式,将是解决我国目前城市环境基础设施建设和运营的有效手段,提高城镇生活污水集中处理的最终途径。     

九龙江河口表层水体及沉积物中甲烷的分布和环境控制因素研究

利用静态顶空法在2009年7月测定了九龙江河口表层水体和沉积物孔隙水中甲烷浓度以及相关的环境参数,并对甲烷浓度分布特征和控制因素进行了相关的分析.结果显示56个河口表层水的甲烷浓度在10.7～456.7 nmol.L-1之间,饱和度远超过大气平衡甲烷浓度,由河口上端向中下端逐渐减小.4个站位(B1、B2、B3和B4站位)孔隙水中平均甲烷浓度(分别为2 212、447、28和5μmol.L-1)从河口上端向下端快速减小,与水体甲烷浓度水平变化趋势基本一致.B1～B4站位孔隙水中硫酸盐的浓度依次增大,其平均值分别为0.13、0.64、5.3和16.3 mmol.L-1.九龙江河口表层水和孔隙水中甲烷浓度变化趋势,表明河口上端沉积物中产甲烷菌降解有机质产生甲烷,并以扩散的形式通过沉积物-水界面进入上部水体,导致河口上端甲烷浓度增加;而在河口下端海相区随着孔隙水中硫酸盐浓度增加,沉积物中产甲烷过程逐渐受到硫酸盐还原过程的抑制,河口下端孔隙水和表层水甲烷浓度相应降低.B2和B3站位孔隙水中甲烷浓度随着深度增加分别由43和10μmol.L-1增加至1 051和57μmol.L-1,结合总有机碳(TOC)和硫酸盐在沉积柱剖面上的变化趋势,表明大量甲烷在沉积物硫酸盐-甲烷过渡带中被厌氧氧化,这进一步抑制了沉积物中甲烷的释放强度.九龙江河口沉积物中甲烷的产生过程除有机质以外还受到孔隙水中硫酸盐浓度的控制,而水体甲烷主要来源于河口上端盐度相对较低且富有机质的红树林潮间带湿地的释放.     

加强乡镇生态建设 提升农村生态文明

风景优美、生态资源保护完好的浩饶山镇,自开展创建国家级生态乡镇工作以来,以坚持政府组织、部门配合、全镇上下通力合作的工作态势,促使创建工作有序进行。本文主要对浩绕山镇的自然状况、社会经济、生态环境等方面的现状做了详细的调查与评价,通过对浩扰山镇创建工作的深度剖析,更好的开展国家级生态乡镇创建工作。