Resources policy and mine closure in South Africa: The case of the Free State Goldfields

There is increasing international pressure to ensure that mining development is aligned with local and national development objectives. In South Africa, legislation requires mining companies to produce Social and Labour Plans, which are aimed at addressing local developmental concerns. Against the background of the new mining legislation in South Africa, this paper evaluates attempts to address mine downscaling in the Free State Goldfields over the past two decades. The analysis shows that despite an improved legislative environment, the outcomes in respect of integrated planning are disappointing, owing mainly to a lack of trust and government incapacity to enact the new legislation. It is argued that legislative changes and a national response in respect of mine downscaling are required.     

气孔开闭与锶叶面吸收的相互影响

叶面吸收是核素长距离迁移进入植物的首要方式,研究气孔开闭与核素叶面吸收之间的相关关系具有重要意义。以研究最为广泛的锶(Sr)作为核素代表,以双子叶乔木红叶石楠叶片为研究对象,用脱落酸(ABA)和激动素(KT)调节气孔的开闭,探讨核素离子的气孔吸收作用及叶面核素吸收对气孔开闭的影响。结果表明:Sr对气孔开启有明显的抑制作用,浓度越高抑制效果越明显;在10 mmol/L的Sr溶液中暴露2 h后,气孔开启度仅为-105.18%;气孔开闭对核素吸收存在显著的影响,开启度越高核素叶面吸收越强;72 h时,Sr单位叶面吸收量为9.61μg/cm2,添加20 mg/L ABA后叶面吸收量下降13.1%(8.35μg/cm2),而添加20 mg/L KT后叶面吸收量增加21.6%(11.69μg/cm2)。     

水雾扩散及其对环境影响的模拟研究

利用三维有量方程闭合大气界层模式攻随机游动模式组成一个大气扩散实用模拟系统，模式考虑了测流夹卷，雾漳蒸发，重方学降等物理过程，模拟研究了水电站泄洪产生的水雾的扩散及其对环境相对湿度的影响，模拟结果表明，中性层结条件下，国扩散距离为２５８ｍ，水雾最远影响距离为１ｋｍ左右，使环境相对温度增加１％～３％，大气稳定度对水雾扩散有很大的影响，不稳定情况下，水雾扩散和影响范围较小；但因国蒸发量大，国扩散和影响     

南京北郊云凝结核活化特征观测及闭合研究

采用SMPS-CCNC联用全扫描的方法,于2016年11~12月在南京北郊地区,对8.2~346nm粒径段的气溶胶粒子展开了粒径分辨的云凝结核（CCN）活化特征观测,并利用6种参数化方法对CCN数浓度进行了闭合研究.结果表明本次观测中南京地区的气溶胶CCN活性和吸湿性均较高,其中平均吸湿性参数（k）为0.31.通过污染天和清洁天CCN特征的对比发现,污染天气溶胶和CCN数浓度均较高,但CCN活性和气溶胶吸湿性却较差,可能是由于新鲜排放的黑炭或有机物的影响.对比6种参数化方法的闭合结果,发现利用截断粒径和临界干粒径这两种参数对CCN数浓度进行预报的结果最为理想.此外,探讨了不同时间分辨率的参数对闭合结果的影响,对比发现参数时间分辨率的提高只增加了闭合结果R²的值,对闭合斜率的影响基本可以忽略,因此综合考虑,本研究可直接利用各参数的整体日变化平均来进行CCN数浓度的闭合.     

生活垃圾填埋场封场前后渗滤液环境监测方案的实证分析

分析了生活垃圾填埋场渗滤液产生、污染成分及特点,介绍了监测方案制定的基本原则和工作程序,明确了生活垃圾填埋场封场前后渗滤液环境监测的要求,并实证分析两种监测方案的异同。     

京津冀典型城市大气颗粒物化学成分同步观测研究

为解析京津冀城市群大气颗粒物化学组成,寻求区域大气污染协同防控方法,分别在北京、天津、唐山和保定4个典型城市和兴隆大气本底对照区设置观测站点,使用环境颗粒物在线监测仪和安德森撞击式9级采样器获取不同粒径段大气颗粒物的质量浓度并分析其化学成分.结果表明,上述4个城市站点PM10年均值（2009年6月～2010年5月）分别...     

Evaluating the potential of biodiversity offsets to achieve net gain

Evaluating the outcomes and tracking the trajectory of biodiversity offsets is essential to demonstrating their effectiveness as a mechanism to conciliate development and conservation. We reviewed the literature to determine the principles that should underpin biodiversity offset planning and the criteria for offset evaluation at the project level. According to the literature, the core principles of equivalence, additionality, and permanence are used as criteria to evaluate conservation outcomes of offsets. We applied the criteria to evaluate offsets of a large iron ore mining project in the Atlantic Forest in Brazil. We examined equivalence in terms of the amount of area per biodiversity value affected and fauna and flora similarity, additionality in terms of landscape connectivity, and permanence in terms of guarantees to ensure protection and restoration offsets lasting outcomes. We found an offset ratio (amount of affected area:offset area) of 1:1.8 for forests and 1:2 for grasslands. Ecological equivalence (i.e., similarity between affected and offset areas) was found for forested areas, but not for ferruginous rupestrian grasslands or for fauna. Landscape metrics showed that connectivity improved relative to the preproject situation as a result of locating restoration offsets in the largest and best-connected forest patch. Permanence of offsets was addressed by establishing covenants and management measures, but financial guarantees to cover maintenance costs after mine closure were lacking. Offsets should be equivalent in type and size, provide conservation outcomes that would not be obtained without them (additionality), and be lasting (permanence). To monitor and evaluate offsets, it is necessary to determine how well these 3 principles are applied in the planning, implementation, and maintenance of offsets. Achieving measurable conservation outcomes from offsets is a long-term endeavor that requires sustained management support, and is information intensive. Thus, offsets require ongoing monitoring and evaluation as well as adaptive management.     

Economic and financial aspects of mine closure

Today, mine reclamation is a key component to a successful mine plan. Most of the industrialized nations have recognized the need to make mining activities relatively environmentally friendly, if they want to continue to benefit from the economic gains from mineral resource development. Countries such as the United States, Canada, Australia and South Africa are leaders in the field and have implemented relatively sophisticated legislation to ensure environmentally correct mine closure. These countries rely on a combination of strict control strategies and economic penalties to ensure compliance. Yet, from the firm's perspective, reclamation activities are counterproductive as they cut into profits. In order to attract economic development and earn much needed economic capital, most of the rest of the world, particularly the developing countries, lack effective mine closure legislation. The traditional command and control type of legislation that is sometimes used is either vague and therefore avoided, or not enforced appropriately, resulting in an undesirable level of environmental degradation. With the use of case studies from Brazil, this article shows that direct controls are effective in some instances and not in others. It proposes that economic and financial tools may be more effective than the traditional direct controls in getting firms to comply with environmental standards, particularly in developing countries where environmental compliance is more difficult to achieve. It explains the use of performance bonding as one type of economic incentive that has proven to be an effective environmental policy in mine planning and closure. The authors additionally push beyond the typical style of performance bonds to introduce a flexible bonding and insurance system that allows governments to maintain strict environmental standards but limits firms financial exposure during the mining process. Such a system learns from the successes of the industrialized countries that use performance bonding and is sensitive to the needs of developing nations to attract investment yet maintain environmental integrity.     

北京不同污染地区园林植物对空气颗粒物的滞纳能力

城市园林植物作为城市生态系统的重要组成成分,在滞纳空气颗粒物,净化城市大气环境发挥着重要作用.本文以北京市6种常见园林植物为研究对象,利用气溶胶再发生器(QRJZFSQ-I)测定了不同污染地区叶片对大气颗粒物的滞纳能力,同时利用环境扫描电镜观察了测试树种叶片结构变化.结果表明:1在所测的树种中,针叶树种单位叶面积滞纳空气颗粒物的能力比阔叶树种高,其中油松(Pinus tabuliformis)滞纳量最高,为(3.89±0.026)μg·cm-2,其次是白皮松(Pinus bungeana),为(2.82±0.392)μg·cm-2,毛白杨(Populus tomentosa)最小,为(2.00±0.118)μg·cm-2;2通过观察叶片微观形态结构发现,针叶树种气孔排列紧密,气孔密度比阔叶树种大,表面粗糙度高于阔叶树种,而且能够分泌油脂;3在不同污染区,相同树种叶片滞纳PM10存在显著差异,五环周围的树种叶片单位叶面积滞纳PM10能力要高于植物园的,而相同树种叶片单位叶面积滞纳PM2.5则无明显差异;4在不同污染区下,叶片结构发生了重要的适应性变化,相对于轻污染区,在重污染区植物叶片外表皮细胞收缩,叶片表皮纹理变得更加粗糙,气孔频度和绒毛长度增加.尽管暴露于重污染区植物叶片发生重要变化,但是这些植物仍然能够正常健康地生长.