试论复垦的概念及其与生态重建的关系

基于国内外大量的文献资料,在剖析国外对“土地复垦”的定义、目标的理解和介绍有关国外复垦法规、复垦研究内容和历史的基础上,从复垦和生态重建的基本概念入手,深入探讨了二者内涵与关系,认为：“复垦”的研究十分重视生态原则,也一直将生态重建作为其研究的焦点。因此,“复垦”一词的实质是既恢复土地资源,又重建生态平衡,即“复垦”包括土地复垦和生态重建两方面。     

黄土露天矿区排土场重构土壤典型物理性质空间差异分析

土壤典型物理性质决定了土壤的肥力状况,同时也影响植物群落的生长。目前矿区复垦方面的研究大多为研究土壤物理性质的空间差异或是植被盖度对表层土壤物理性质的影响,很少有针对不同植被覆盖类型对重构土壤物理性质的影响的研究。运用描述性统计分析法、单因素方差分析法等方法研究平朔矿区重构土壤典型物理性质在水平及垂向方向的差异,并依照研究区植被生长状况进行分组,研究不同植被覆盖类型下的土壤物理性质差异。该研究旨在得到土壤性质及植被间的影响机理,对未来复垦工作的土壤重构及植被重建的提供指导。结果表明,(1)土壤典型物理性质在垂向上均属于弱变异,随着深度增加,复垦效果减弱。土壤容重及孔隙度存在层间显著差异,土壤容重随着土壤深度增加增大,土壤孔隙度随着土壤深度增加减小。(2)研究区重构土壤典型物理性质在水平方向均属于中等变异,随着深度减小,各性质的差异减小。(3)不同植被覆盖类型下的土壤容重和孔隙度在0-10 cm及20-60 cm深度存在显著差异,但在各土壤粒级含量上无显著差异。研究区分布最多的土质类型是壤土。乔木植被生长有助于土壤粒级的减小,草本植被对浅层土壤物理性质改良效果优于深层土壤。未来在进行植被重建工程时应适当根据实地土壤质地情况选择适宜植被。     

伊犁地区历史径流深度场的重建

本文利用伊犁地区的树轮年表，首先进行年轮场与流量场的典型相关计算，揭示出两场间的较好相关性；进而重建伊犁地区流量场，分析其主要空间分布型；最后在绘制伊犁地区１８０年来四个径流丰枯阶段径流深度等值线图的基础上，计算各丰枯期的地表水资源量值，并讨论其历史变化，得出了一些有益的结论。     

‘Here,I'm not at ease’: anthropological perspectives on community resilience

A number of recent studies on disaster reconstruction have focused on the concept of community resilience and its importance in the recovery of communities from collective trauma. This article reviews the contributions the anthropological literature and the ethnographic case studies of two post‐Hurricane Mitch housing reconstruction sites make to the theorising of community and resilience in post‐disaster reconstruction. Specifically, the article demonstrates that communities are not static or neatly bounded entities that remain constant before, during and after a disaster; rather, communities take on shape and qualities depending on the relationships in which they engage with government agencies and aid organisations before and after disasters. Consequently, the article argues that definitions of community resilience and disaster mitigation programmes must take the emergent and relational nature of communities into account in order to address the long‐term causes and impacts of disasters.     

低碳生态视角下的灾后统筹重建模式——以汶川地震为例

在汶川8.0级地震及其次生灾害的共用作用下,地震灾区生态环境变得更加脆弱.灾后3年灾区重建任务主要集中在经济社会方面,对生态环境重建的投入不足,以及灾区高碳化产业结构,造成灾区生态系统功能退化,灾区生态系统出现弱均衡现象,严重影响灾区生态系统的可持续发展.灾区生态弱均衡可防可控,通过在灾区树立低碳均衡发展思想,制定灾区生态低碳发展路径;加大节能减排工作力度,调整灾区产业结构;推行退耕还林政策,发展林木产业,推进生态农业低碳建设;构建森林碳汇示范基地,实施低碳生态战略,推动灾区生态系统全面可持续发展.     

L'Aquila's reconstruction challenges: has Italy learned from its previous earthquake disasters?

Italy is an earthquake‐prone country and its disaster emergency response experiences over the past few decades have varied greatly, with some being much more successful than others. Overall, however, its reconstruction efforts have been criticised for being ad hoc, delayed, ineffective, and untargeted. In addition, while the emergency relief response to the L'Aquila earthquake of 6 April 2009—the primary case study in this evaluation—seems to have been successful, the reconstruction initiative got off to a very problematic start. To explore the root causes of this phenomenon, the paper argues that, owing to the way in which Italian Prime Minister Silvio Berlusconi has politicised the process, the L'Aquila reconstruction endeavour is likely to suffer problems with local ownership, national/regional/municipal coordination, and corruption. It concludes with a set of recommendations aimed at addressing the pitfalls that may confront the L'Aquila reconstruction process over the next few years.     

一种改进的事故再现蒙特卡罗优化算法

为使事故再现结果更符合实际情况,对事故再现中的计算过程进行优化。基于蒙特卡罗方法和随机加权方法,提出一种改进的事故再现蒙特卡罗优化算法。该算法以二维碰撞模型和车辆轨迹模型为计算模型,选择碰撞点位置、碰撞前速度、法向恢复系数为优化参数,以实际车辆碰撞后运动轨迹离差最小为优化目标。分别用所提出的改进算法和Pc-Crash中的优化方法对一算例进行优化。结果表明,改进算法在准确度和稳定性等方面优于Pc-Crash中的方法。利用改进的事故再现蒙特卡罗优化算法,不仅能获得最优的事故再现结果,还能获得再现结果落在任意区间的概率。     

Longitudinal‐Vertical Hydrodynamic and Turbidity Simulations for Prediction of Dam Reconstruction Effects in Asian Monsoon Area1

Abstract: This research investigates possible impacts of enlarged water body according to dam reconstruction on the hydrodynamics and water quality of the reservoir using a laterally averaged, two‐dimensional hydrodynamic and transport model, CE‐QUAL‐W2. The lake was formed by the artificial dam in 1983 for agricultural water supply and is currently under consideration of reconstruction so as to expand the volume of reservoir for flood control as well as water supply in downstream areas. To calibrate and validate the model, field‐collected data were compared with model predictions for water level fluctuations and water temperature during the years of 2001 (from January to December) and 2003 (from March to November). The model results showed a good agreement with field measurements both in calibration and verification. Utilizing the model, impacts of dam reconstruction on the thermal hydrodynamics and turbid current were predicted. From the model results, dam reconstruction limited the depth of thermal stratification below 10 meter and formed steep temperature gradient between epilimnion and hypolimnion. The restricted thermal stratification persisted up to the end of September. This result indicated that thermal stratification would become stronger during summer and stay longer after dam reconstruction. In addition, the restricted thermal stratification caused vertical circulation of water mixing lower than 10 meter and isolated the upper water layer from the lower water layer which increased the volume of hypolimnetic water with low temperature. The vertical circulation near the surface also mitigated propagation of density plume within the depth of 10 m which would remain the hypolimnetic water clean.     

基于相空间重构理论的天津市近海水质混沌特性研究

针对我国近海水质污染呈现的复杂非线性特征,通过对混沌理论中的相空间重构方法进行研究,提出了一种新的完全基于环境监测数据的近海水质分析方法。以天津市近岸海域为例,首先,根据相空间重构理论,对近海各监测点的1维COD时间序列进行多维相空间重构,求得最佳嵌入维数mmin和吸引子关联维数D;然后,采用Wolf方法计算最佳嵌入维数mmin下重构相空间的最大Lyapunov指数λ1。计算结果显示各个监测点的关联维数D均在3.3左右,最大Lyapunov指数λ1均大于0,表明近海水质COD时间序列具有明显的混沌特征,近海水质系统是一个多维系统,貌似随机无规律的近海水质系统具有内在的、固有的规律。应用表明,该方法实用性强,为进一步采用混沌理论对近海水质进行预测提供了理论依据,非常有利于近海水环境的管理。     

地震灾后生态系统重建中的植被恢复初探

本文从地震对震区生态系统的破坏和退化出发,探讨了不同生态系统重建中植被恢复的技术和做法.大地震及其诱发的次生灾害毁坏了植被生存的土壤环境,致使土壤遭受重金属、有机物以及核辐射的污染,而植被可以修复退化的土壤生态系统.对于森林,草地.江河等自然生态系统,植被选择应以原生种类为主,以促进生态系统进行原生演替;而农田、城市绿地生态系统,植被恢复应以生产生活、景观营造、生物修复为目的,宜选择当地主要优势农作物、观赏性好、抗污染的植物,以控制生态系统次生演替的方向和速度.在各类生态系统重建中,应防止外来有害物种的入侵.