中国法规大气扩散模式及其与其他模式的比较

介绍了中国法规性大气扩散模式(CRADM),分析了CRADM和西方一些模式(如HPDM,AMS)的差别。采用同样条件作为输入,比较并讨论了CRADM,HPDM和AMS在各方面的性能差异。分析了中国大气扩散模式在环境影响评价应用中出现的一些问题,提出了改进建议。特别地,研究表明中性条件下Briggs烟气抬升公式对实际抬升有过高估计,原因是没有考虑环境湍流对烟羽的累积作用      

条形障碍物对瓦斯爆炸特性影响研究

我国煤矿瓦斯爆炸事故不断出现,造成了巨大的人员伤亡和经济损失,在置障条件下研究瓦斯爆炸特性,对预防和减少瓦斯爆炸事故具有重要意义。利用水平管道式爆炸试验装置,研究密闭管道内条形障碍物的数量和阻塞率对管道内瓦斯最大爆炸压力、火焰速度、最大爆炸压力上升速率和爆炸指数的影响以及敞口状态的影响。研究表明:障碍物对瓦斯爆炸具有显著激励作用,管道内瓦斯最大爆炸压力、火焰速度、最大爆炸压力上升速率和爆炸指数均显著增大,随着障碍物数量和阻塞率的增加,激励作用越明显;敞口状态下管道内最大爆炸压力、最大爆炸压力上升速率和爆炸指数均显著减小,火焰持续传播。研究结果对防治煤矿瓦斯爆炸事故提供一定的理论支持。     

基于热风险理论对道化学评价中物质系数的研究

随着本质安全研究的深入,道化学评价方法中物质系数MF的计算已不能准确描述反应物本身的热风险大小。在道化学评价方法中引入热风险概念,比较热危险性评价方法和道化学评价方法间相异点;以六甲基磷酰三胺工艺为研究对象,用DSC量热仪对反应物进行分析得出放热速率q、反应波峰峰值、单位质量的反应焓Hr,对采集的工艺参数用热力学理论外推法、基因贡献法得出活化能E、比热容CP并以此求出最大反应失效时间TMRad、绝热温升Qad、物质系数MF值以及工艺单元中物料量。得出最大反应失效时间与物质系数MF间具有相关性,道化学评价方法对因失效反应引发二次反应的热风险评估也适用。     

Sea level rise and eelgrass (Zostera marina) production: A spatially explicit relative elevation model for Padilla Bay, WA

The dynamics that govern the elevation of a coastal wetland relative to sea level are complex, involving non-linear feedbacks among opposing processes. Changes in the balance between these processes can result in significant alterations to vegetation communities that are adapted to a specific range of water levels. Given that current sedimentation rates in Padilla Bay, Washington are likely less than historical levels and that eustatic sea level rise is accelerating, the extensive Zostera marina (eelgrass) meadows in the bay may be at risk of eventual submergence. We developed a spatially explicit relative elevation model and used it to project changes in the productivity and distribution of eelgrass in Padilla Bay over the next century. The model is mechanistic and incorporates many of the processes and feedbacks that govern coastal wetland elevation change. Accretion estimates made using ²¹⁰Pb dating of sediment cores, sediment characteristics measured within cores, and eelgrass productivity and decomposition data were used to initialize and calibrate the model. Validation was performed using an elevation change rate measured with a network of surface elevation tables. Both the field data and model simulations revealed a net accretion deficit for the bay. Simulations using current rates of sea level rise indicated an overall expansion of eelgrass within Padilla Bay over the next century as it migrates from the center of the bay shoreward.     

珠江三角洲水位演变分析

全球气候变暖导致的海平面加速上升已是不争的事实,其长期累积的结果将给沿海地区造成巨大威胁。利用层次聚类分析法、灰关联法、相关分析法等重点分析了海平面上升对珠江三角洲水位的影响。结果显示：海平面上升对珠江三角洲代表站的年平均水位和年最低水位的影响大于对年最高水位的影响;海平面上升对马口站和三水站水位的影响小于河床下切和径流的影响;海平面上升对珠江河口区水位的影响由三角洲深处向口门区有增强趋势。掌握海平面上升对水位的影响规律,对于河口地区的防灾减灾和水资源的合理开发利用具有重要的指导意义。     

Adaptation in situ or retreat? A multivariate approach to explore the factors that guide the peoples' preference against the impacts of sea level rise in coastal Bangladesh

This paper is aimed to identify the factors that influence peoples' preference for adaptation against the impacts of sea level rise (SLR). A total of 285 respondents from three coastal villages in Bangladesh are randomly interviewed using a semi-structured questionnaire. First, employing the principal component analysis various factors that influence adaptation preferences of people are identified. These factors are related to “demographic and social aspects”, “wealth and economic standing”, “past coping and adaptive behaviour”, “climate knowledge and information” and “spatial aspect” of life. What is common in these factors is their ability to influence peoples' vulnerability. Finally, the binomial logistic regression model is employed to compute the explanatory power of these factors to predict the respondents' preference for adaptation in situ over retreat or vice versa. Model findings are robust for two scenarios of SLR, i.e. 2050–2075 (LR χ ²?=?133.65, pseudo-R ²?=?0.53, p?<?0.001) and 2080–2100 (LR χ ²?=?282.61, pseudo-R ²?=?0.85, p?<?0.001). Therefore, it is concluded that to avoid relocation of substantial number of people initiative for encouraging adaptation in situ must be taken along side establishment of safe shelter, community radio service and campaign for raising climate awareness.     

模拟海平面上升和氮负荷增加对河口感潮沼泽湿地CO2垂直交换的影响

海平面上升和氮负荷增加是入海河流河口面临的两个主要全球性环境问题.揭示河口潮滩沼泽湿地CO₂垂直通量对二者及交互作用的响应,对于科学评估全球变化背景下的河口潮滩沼泽湿地生态系统蓝碳功能具有重要的科学意义.本研究以闽江河口鳝鱼滩中潮滩短叶茳芏湿地为研究对象,在野外原位实施模拟海平面上升、氮负荷增加及二者交互作用的实验处理近1年后,在2019年冬季各月的大潮日白天涨潮前、平潮期及落潮后3个阶段,运用透明静态箱（或遮光布遮光）+Li-6800光合作用仪对短叶茳芏湿地生态系统净CO₂交换（NEE）和生态系统呼吸（ER）进行测定.结果发现,与对照处理相比,冬季尺度3种处理下短叶茳芏湿地生态系统NEE均显著增加;模拟海平面上升影响下短叶茳芏湿地生态系统ER无显著变化;氮负荷增加及二者交互作用下,短叶茳芏湿地ER均显著增加.模拟海平面上升、氮负荷增加及二者交互作用情景下,短叶茳芏湿地生态系统总初级生产力（GPP）均明显增加.研究表明,在未考虑甲烷排放的情景下,即使在冬季,海平面上升、氮负荷增加及二者交互作用将可能增加亚热带河口潮滩半咸水沼泽湿地的碳汇功能.     

江苏沿海地区的相对海平面上升及其灾害性影响研究

江苏海岸是全国潮滩最集中分布区，其面积约占全国的１／４，沿海地区地势低平，相对海平面上升幅度较大，是全国少数几个受海平面上升危害最严重的地区之一。初步估算，２１世纪前半期该地区不同岸段相对海平面上升速率将可能达到４．５～９．５ｍｍ／ａ，约为同期全球平均上升速率的２～３倍。其灾害性影响主要集中在：①造成堤外潮滩湿地资源损失，相对海平面上升５０ｃｍ，因直接淹没、侵蚀加剧和淤涨减缓造成的潮滩损失面积将超过５×１０４ｈｍ２，湿地损失面积达２．４×１０４ｈｍ２；②降低海堤防御标准、危及海堤自身和受保护地区安全，相对海平面上升５０ｃｍ，该地区现有海堤防御标准将由现状５０～１００年一遇降为２０～５０年一遇；遇５０年一遇风暴高潮位，全区受潮水漫溢的海堤长度将比现状增加１７３ｋｍ以上，占海堤总长的１／４；③阻碍低洼地的洪水排泄、加剧洪涝灾害损失，相对海平面上升４０ｃｍ，苏北里下河和苏南太湖湖东两片洼地的自然排水能力将可能分别下降约２５％和２０％，若两洼地分别重现１９９１年型和１９５４年型洪水，则因海平面上升增加的受淹面积将超过４×１０４ｈｍ２     

对高层建筑临时高压消防给水系统若干规定的探讨

高层建筑的消防设计审核是消防执法中的重要环节.以规范为指导,根据我国国情和具体工程设计情况,对高层建筑临时高压消防水系统中有关消防水泵房的出水管的布置、高位消防水箱的容积以及增压设施的设置几方面的规定进行了探讨.     

Nitrogen accumulation and plant species replacement in three salt marsh systems in the Wadden Sea

Salt marsh development on the coastal barrier island of Schiermonnikoog (The Netherlands) was compared with two other salt marsh systems in the Wadden Sea. Accretion rate, nitrogen accumulation and changes in plant species composition were investigated using chronosequences. The age of the marsh was estimated from aerial photographs and old maps. In 7230 plots, the elevation of the marsh surface, the thickness of the sediment layer (clay) and the presence of plant species was recorded. In addition, the nitrogen pool was measured at each successional stage. Accretion rates were similar in the three salt marshes. Higher accretion rates were found at younger marshes. A strong linear relationship between nitrogen pool size and thickness of the clay layer was found for the three marshes. The accumulation rate of nitrogen is therefore strongly related to the accretion rate. Thus, more nitrogen is present in the sediment of later successional stages where more clay has accumulated. On the high salt marsh (55 cm+MHT),Ameria maritima disappeared andArtemisia maritima, Juncus gerardi andElymus athericus established at sites with a thicker clay layer. On the low salt marsh (25 cm+MHT),Plantago maritima, Puccinellia maritima andLimonium vulgare disappeared andAtriplex (Halimione) portulacoides established. Apparently, with the accumulation of clay and therefore of nitrogen, tall growing species take over in salt marshes not grazed by livestock.