广西凤凰锰矿区废弃地生态环境问题及恢复治理对策

凤凰锰矿区是我国著名的大型锰矿区之一,历经数十年露天开采,遍布成百上千废弃采矿深坑,地表裸露光秃,重金属元素Mn、Cd、Pb、Cr等已污染土壤,危害植物生长,生态环境破坏严重。针对该矿区的生态环境现状问题,提出生态恢复治理对策和建议,认为生态恢复应从加强矿区土壤性状、有害元素赋存状态研究入手,指导生态恢复,复绿美化山川,营造和谐的生态景观;指出要重视尾矿资源的再开发利用,提高生态治理综合效益;强调重视利用生物治理技术修复重金属元素污染废弃地,恢复土壤的生态功能和永续利用;建议加强管理组织综合研究,建立凤凰矿区废弃地生态恢复创新示范工程,推动广西矿山生态环境治理的发展。     

针对城市河流功能需求的生态修复技术概述

通过分析城市河流功能需求及其演变趋势,介绍了现有各生态修复技术,论述城市河流生态修复的发展趋势,总结针对各种功能的生态修复技术,旨在说明城市河流的修复需考虑到其功能需求的特殊性,针对不同的城市河流,生态修复的侧重点也应有所变化,以起到更好的修复效果。     

基于LUCC的露天矿区景观格局研究一以黑岱沟露天煤矿为例

露天矿区开发活动主要是在景观层次上进行,其直接导致土地利用／覆被变化（LandUse／Cover Change,LUCC）。本文以黑岱沟大型露天煤矿1987年、1990年、2000年及2010年4期遥感影像的土地利用数据为基础,基于GIS空间分析功能,以破碎度、分离度和优势度景观格局指数和景观类型脆弱度为指标,分析景观格局现状。研究显示：开发初期,耕地和草地虽有所减少,但所占面积保持在80％以上;生态恢复开始后,土地类型向林地和草地转移的面积逐渐增多。景观水平上分析显示,景观上破碎化程度加大,煤矿建设用地斑块面积逐年增大。从景观指数看,耕地、草地、未利用地的破碎度、分离度指数变化呈上升或不稳定状态,建设用地的破碎度和分离度指数有所减小;优势景观类型有所改变,建设用地对于区域景观的控制作用逐渐加强。     

Historical and Future Stream Temperature Change Predicted by a Lidar‐Based Assessment of Riparian Condition and Channel Width

Riparian forests attenuate solar radiation, thereby mediating an important component of the thermal budget of streams. Here, we investigate the relationship between riparian degradation, stream temperature, and channel width in the Chehalis River Basin, Washington State. We used lidar data to measure canopy opening angle, the angle formed between the channel center and trees on both banks; we assumed historical tree heights and calculated the change in canopy angle relative to historical conditions. We then developed an empirical relationship between canopy angle and water temperature using existing data, and simulated temperatures between 2002 and 2080 by combining a tree growth model with climate change scenarios from the NorWeST regional prediction. The greatest change between historical and current conditions (~7°C) occurred in developed portions of the river network, with the highest values of change predicted at channel widths less than ~40 m. Tree growth lessened climate change increases in maximum temperature and the length of river exceeding biologically critical thresholds by ~50%–60%. Moreover, the maximum temperature of channels with bankfull widths less than ~50 m remained similar to current conditions, despite climate change increases. Our findings are consistent with a possible role for the riparian landscape in explaining the low sensitivity of stream temperatures to air temperatures observed in some small mountain streams.     

叙永县落卜硫铁矿矿山土壤环境治理效果研究

川南地区广泛分布无序开采的硫铁矿矿山,早期开采方式导致土壤酸化、重金属含量高等环境问题出现,2012年政府集中治理连片矿山地质环境恢复问题.研究了落卜硫铁矿矿区的土壤使用石灰和零散坡耕地整治对土壤酸化、重金属钝化修复效果.通过野外调查、采样分析测试、对比综合评价等方法证明,向土壤中投放石灰可以有效改善土壤酸化.在治理区...     

鸭子河湿地的生态健康评价与恢复研究

从湿地现状、服务功能和外环境影响3方面构建了城镇区域内湿地生态健康评价指标体系,采用层次分析法（AHP）和模糊综合评价法,对广汉鸭子河湿地这一城镇区域内河滩型湿地生态系统健康状况进行评价。结果表明,在广汉市城市化进程中,该湿地的生态系统受到了一定程度的影响,就总体而言,湿地生态系统结构完整,基本功能依然具备,但栖息地功能有一定的退化,在整体上属于亚健康状态。根据评价结果及退化成因分析,提出了相应的恢复措施,对广汉市城市化进程中鸭子河湿地的保护提供了重要的决策依据,对同类型的湿地保护具有指导意义和借鉴价值。     

Rethinking remediation: mine reclamation,environmental justice,and relations of care

ABSTRACT

To date, research on mine remediation in North America has focused primarily on technical management; relatively less is known about the historical, political and social dimensions of remediation. Remediation, as a continuation of the mining process, alters local landscapes and economies and can be both dangerous and beneficial for surrounding communities. Because remediation projects tend to focus on the technical aspects of clean-up, such projects risk overlooking the environmental injustices associated with past development and obscuring blame or responsibility from industry and government for environmental degradation. Insofar as it is understood as cleaning up or repairing environmental damage, remediation is generally seen as “doing the good” and is less amenable to political or ethical challenges based on community concerns or values. This paper argues that greater attention needs to be paid to public participation and justice concerns associated with cleaning up mine sites. Drawing from the literatures on ecological restoration, environmental justice, reconciliation, discard studies, and matters of care, we highlight critical, yet overlooked issues in the remediation of post-mining landscapes. We argue that remediation projects present a unique opportunity for the negotiation and articulation of morals, values, histories, and physical experiences associated with mine sites and we seek to re-frame remediation as an ongoing, creative process of community healing.     

Development of Regional Curves for Hydrologic Landscape Regions (HLR) in the Contiguous United States

Regional curves relate drainage area to the bankfull channel characteristics discharge, cross‐sectional area, width, and mean depth. These curves are used for a variety of purposes, including aiding in the field identification of bankfull elevation and in the natural channel design process. When developing regional curves, the degree to which landform, geology, climate, and vegetation influence stream systems within a single physiographic province may not be fully considered. This study examined the use of the U.S. Geological Survey's Hydrologic Landscape Regions (HLR), as well as data from 2,856 independent sites throughout the contiguous United States (U.S.), to develop a set of regional curves (bankfull discharge, cross‐sectional area, width, and mean depth) for (1) the contiguous U.S., (2) each of the 20 HLRs, (3) each of the eight physiographic divisions, (4) 22 of the 25 physiographic provinces, and (5) individual HLRs within the physiographic provinces. These regional curves were then compared to each other, as well as those from the literature. Regional curves developed for individual HLRs, physiographic divisions, and physiographic provinces tended to outperform the contiguous U.S. indicating increased stratification was beneficial. Further stratifying physiographic provinces by HLR markedly improved regional curve reliability. Use of HLR as a basis of regional curve development, rather than physiographic region alone, may allow for the development of more robust regional curves.     

光催化降解亚甲基蓝的影响因素及动力学研究

进行了亚甲基蓝在硫化镉上的暗吸附反应,并作Langmuir拟合和Freundlich拟合计算其吸附速率常数。通过实验证明硫化镉光催化降解亚甲基蓝符合一级动力学反应。在低光强下,反应速率常数随着光强的增大而增大,两者之间存在显著的线性关系。改变光催化反应温度,计算表观活化能Ea为19.13kJ/mol,证明温度对反应影响较小。     

新污染物多环芳烃衍生物的来源、分布与光化学行为

环境中多环芳烃衍生物(SPAHs)来源广泛,具有“三致”效应,毒性与PAHs母体相当甚至高于母体,是一类具有较高风险的新型有机污染物.大气和表层水体等环境介质中,光化学降解是其重要的消减方式.在梳理文献的基础上,发现SPAHs在来源、分布、行为和风险研究方面与传统污染物PAHs相比有了新的突破.通过总结新污染物SPAHs的环境分布特征与光化学行为研究的最新进展,介绍了3类SPAHs的来源和形成机制,重点评述了不同环境介质中的存在状况与分布特征,讨论了水、冰等介质中SPAHs光化学转化动力学、反应路径以及影响因素,最后对SPAHs的环境行为和风险研究进行了展望.