江苏省浅水湖泊表层沉积物中重金属污染特征及其风险评价

为揭示江苏省浅水湖泊表层沉积物重金属污染特征,采集江苏省8个浅水湖泊的表层沉积物,测定了8种重金属的含量,并利用地积累指数法和潜在生态风险指数法对沉积物重金属的污染现状以及潜在生态风险程度进行评价。结果表明:江苏省8个浅水湖泊表层沉积物中Mn、Zn、Cr、Ni、Cu、As、Cd、Pb的平均含量分别为634~1 031、66~138、76.0~97.5、39.2~56.3、25.2~50.1、9.9~27.1、0.15~2.98、24.6~51.6mg/kg。地积累指数法评价结果表明,Cd是江苏省8个浅水湖泊表层沉积物中最主要的污染物,Zn、Cu、As、Pb、Ni在一些湖泊为轻度污染,Mn和Cr处于无污染水平。Hkanson潜在生态风险指数法评价结果显示,各湖泊综合潜在生态风险程度的高低顺序为:长荡湖石臼湖白马湖滆湖高邮湖洪泽湖澄湖骆马湖,长荡湖达到严重生态风险水平,石臼湖存在重生态风险,白马湖与滆湖处在中等生态风险水平,而骆马湖、洪泽湖、高邮湖以及澄湖重金属污染则处于低生态风险水平。     

Certainty and uncertainty in understanding global warming

Global warming has greatly concerned the whole world.Owing to the limitation we currently have,it is still difficult to completely understand the mechanism and physical science of climate change.Now both certainty and uncertainty coexist in the understanding of climate warming.This paper aims to summarize certainties and uncertainties in climate-warming studies,which focus on seven key problems related to human activities,namely,global warming,atmospheric concentrations of greenhouse gases,relationship between greenhouse gas emissions and climate warming,climate models,future climate change,2?warming threshold and tipping point in the Earth's system.We should comprehensively take into account the level of certainty and uncertainty in our understanding of climate change while adapting to and mitigating global warming and adjusting our industrial structures accordingly.This would allow us to respond to change with certainty,while avoiding the risks associated with uncertainty.     

自我剥削、禀赋效应与农地流转潜在市场发育——兼论经济欠发达地区小农户生产方式转型

以家庭均包制为主要经营特征的农村土地制度曾一度引致农户农业生产积极性的提高和农业生产效率的快速增长,但由此导致的细碎化小规模的农地经营特征和农业生产成本的上升却造成了农地经营的自我剥削现象普遍存在,加之传统的村庄惯习和土地占有关系诱致的农户对农地的禀赋效应,共同导致农户农地经营的自我剥削属性与土地的市场处置行为呈现出内在运行机制不一致性。为此,本文采用引入交叉项的Probit模型,并利用江西省丰城市和遂川县的706户农户调查数据经验分析了小农户的自我剥削和农地禀赋效应对农地流转潜在市场发育的影响。理论分析表明,农地经营的自我剥削特征与农地市场化具有一致性倾向,但农地的人格化财产属性引致的农户禀赋效应造成了农户农地经营自我剥削感知度的下降,并削弱了要素经营属性与市场配置行为的匹配。经验分析结果发现,小农户低效率农地经营导致的自我剥削与农地禀赋效应分别激励农地流转市场的潜在供给和需求。同时,农地禀赋效应弱化了自我剥削对农地流转潜在需求和供给的诱发作用。为此,本文认为降低农户的土地禀赋效应是欠发达地区小农户转型的总体方向,它为农地由小农户流向生产大户和培育部分小农户成为新型农业经营主体提供保障。文章主要从家庭决策的利益导向化、农地流转市场与劳动力市场发展的不一致性及农村制度供给等维度提出了经济欠发达地区小农户转变农业生产方式,跳出自我剥削陷阱的政策建议。具体措施包括:1切实保障小农户的基本权益,提高他们在家庭资源配置中的预期收益;2在初次规模经营补贴、农业基本补贴机制转变、经营者生产奖励、专业技能培训、市场信息供给等层面加大投入力度,同时完善农村社会保障体系,以降低小农户转型的难度与风险。     

The gap report of global climate change mitigation,finance, and governance after the United States declared its withdrawal from the Paris Agreement

On 1 June 2017, the US President Donald Trump officially announced the withdrawal from the Paris Agreement, thus the study on the reasons of withdrawal, the potential impacts, and coping strategies has become a focus among policy circles and of the international community. Based on the self-developed US Policy Assessment Model, this paper systematically evaluates the three potential “major deficits” in terms of mitigation, climate finance, and global climate governance, as a result of the US withdrawal from the Paris Agreement and puts forward policy suggestions for coping with such transformations accordingly. The study shows that the United States ’withdrawal from the Paris Agreement will affect the existence and implementation of successive climate policies and result in an additional 8.8–13.4% increase in the global emissions reduction deficit. The United States’ withdrawal will also deteriorate the existing climate finance mechanism. The Green Climate Fund (GCF)’s funding gap will increase by US$2 billion, while the gap of long-term climate finance will increase by about US$5 billion a year. Either the China–EU or the “BASIC plus” mechanism could fill the governance deficit caused by the United States and the lack of political momentum may continue for a while in the future.     

Reviews

Alex de Waal Famine Crimes: Politics and the Disaster Relief Industry in Africa Keith Smith Environmental Hazards: Assessing Risk and Reducing Disaster Kenneth Hewitt Regions of Risk: A Geographical Introduction to Disasters John Seaman The Public Health Consequences of Disasters John Prendergast Frontline Diplomacy. Humanitarian Aid and Conflict in Africa John Prendergast Crisis Response. Humanitarian Band-Aids in Sudan and Somalia Christopher Hood and David K.C. Jones Accident and Design: Contemporary Debates on Risk Management D. Hulme and M. Edwards NGOs, States and Donors. Too Close for Comfort? James C. Hathaway Reconceiving International Refugee Law Rhona Flin Sitting in the Hot Seat Donald Meichenbaum On Treating Post-Traumatic Stress Disorder: A Handbook and Practice Manual for Therapy R. Scarpa and R.I. Tilling Monitoring and Mitigation of Volcano Hazards Hanna Schmuck-Widmann Living with Floods: Survival Strategies of Char-dwellers in Bangladesh     

全球气候变化情景下的河北省区域减灾建设

全球气候变化将导致一些地区自然灾害加剧,并将影响到区域的可持续发展.加强区域减灾建设,及早采取相应措施,是适应未来全球气候变化的明智选择.鉴于全球气候变化的影响存在区域差异,不同区域采取的对策也有所区别.本文以河北省为例,分析了该区域自然灾害的类型、历史时期和现在灾害的特点、发生规律及其原因,并根据该区域未来的全球气候变化趋势,提出了一些需要及早实施的战略性减灾对策.     

2003年重大自然灾害回顾

2003年是全球自然灾害重灾年.根据收集到的全球自然灾害记录的数据,客观地对全球主要自然灾害的特征和分布特点进行了分析,并对其成因和发展趋势进行了初步探讨.     

气候变暖对黑龙江省作物生产的影响及其对策

黑龙江省在未来30年和50年内气温分别增高1.9℃和2.4℃的情景下,积温带将向北推移近5个纬距,至2050年,原第一积温带将北移至大兴安岭北部,其余4个积温带将基本消失.模拟结果显示,未来水稻将减产9%,主栽区将北移至黑龙江流域;小麦应压缩耕作面积,未来产量变化不大,应逐步扩大冬小麦试种区域,最后达到规模生产;气候变暖使玉米生育期缩短11.3天,产量减少2.7%,应发展早熟玉米、饲料玉米、经济玉米,提高经济效益;气候变暖对大豆生产极为有利,高产区北移,产量可提高70%～80%,在黑龙江流域松嫩和三江平原北部,特别垦区发展大豆生产优势很大;喜凉经济作物受到一定影响,应向北发展.提出了未来适应性农业的6项对策,特别要安排好主要作物的结构调整及区域分布.     

基于天气分型的北京地区雷电潜势预报预警系统

对1997-2006年457个雷暴过程的环流形势进行对比分析,将北京地区的雷暴天气分为东北低涡低槽、贝蒙低涡低槽、西来槽等11种雷暴天气型;利用南郊观象台(54511站)的探空资料计算对流有效位能、抬升指数和相对风暴螺旋度等33个对流参数,通过与北京地区SAFAIR3000获取的闪电定位资料进行统计分析,提取BCAPE、BLI、MDCI、BIC、KNEW和SWISS等6个对流参数作为北京地区潜势预报参数;采用事件概率回归(REEP)方法,利用获取的6个对流参数作为变量,形成了11种雷暴天气型下的潜势预报方法。利用WRF模式的预报场,建立适用于北京地区3～36 h雷电潜势预报系统。个例实验结果表明其具有较好准确性。由于该系统建立过程中使用了高分辨率探测资料和中尺度模式的输出结果,实现了雷电潜势预报由点到面,由粗到细的突破,对北京地区雷电预警预报具有一定的应用价值。     

泡沼沉积物重金属污染及其潜在生态危害评价——大庆市贴不贴泡案例研究

对贴不贴泡沉积物中的重金属含量进行了分析测定，利用Hakanson潜在生态风险指数方法对其生态危害程度进行了评价。结果表明：贴不贴泡沉积物中Hg，As，Cd，Cu等重金属含量呈现从东南向西北递减的变化特点，而Zn，Cr，Ni，Pb等重金属元素的含量分布则无明显规律。生态风险评价显示，除Cd元素具极强危害外，其余重金属元素均仅具轻微危害。