The distribution and natural degradation of cyanide in goldmine tailings and polluted soil in arid and semiarid areas   总被引：2，自引：0，他引：2  

Li Shehong  Zheng Baoshan  Zhu Jianming  Yu xiaoying 《Environmental Geology》2005,47(8):1150-1154

Farmlands and rivers have been seriously polluted by cyanide from a goldmine tailings dam that collapsed in early spring of 1995 in Yining County, Xinjiang Autonomous Region of China. The cyanide distribution in the polluted farmland and the abandoned tailings dam was studied, three and 4 years after the accident occurred. The results indicated that natural degradation of cyanide in soils is slower than in natural water bodies. The cyanide transport in the soil section is similar to freely soluble salts. In arid and semiarid areas, cyanide can be highly enriched in the salt crust in which the concentration is even higher than the fresh tailings debris though cyanide has decomposed for 4 years. In the polluted farmland, the sticky layer in the soil section can highly adsorb and enrich cyanide so it can partly prevent cyanide transfer to groundwater. According to the characteristics of cyanide natural degradation in soil, the measures for prevention and cure of soil polluted by goldmine tailing dam collapse have been discussed.  相似文献   

滇黔桂盆地及邻区二叠纪层序地层格架及古地理演化   总被引：6，自引：0，他引：6       下载免费PDF全文

梅冥相  郑宽兵  初汉民  邓军  李浩 《古地理学报》2004,6(4):401-418

滇黔桂盆地及邻区的二叠系包括船山统、阳新统和乐平统。船山统与阳新统之交的黔桂运动主幕不整合面、阳新统和乐平统之交的东吴运动主幕不整合面的不整合特征明显,同时因其代表了研究区沉积盆地性质发生较大变化的界面而成为较为典型的I型层序界面。滇黔桂盆地及邻区的二叠系以其明显的沉积相分异而引人注目：在连陆台地上发育含煤地层,而在连陆台地边缘及孤立台地上发育海绵生物礁,形成一个典型的“台-盆-丘-槽”的古地理格局。伴随着强烈的东吴运动第一幕,研究区西北部发生强烈的火山活动,形成分布范围较广的峨嵋山玄武岩;东南部的“钦防残留海槽”关闭,使研究区的古地理格局发生了较大变化。二叠系与三叠系之交发生的较为典型的台地淹没事件形成了一个较为典型的淹没不整合面。根据沉积物的时间演化序列和沉积相的空间展布形式所指示的规律,研究区的二叠系可以划分为以下三级层序：船山统与下伏石炭系顶部的地层构成一个三级层序(SQ¹⁹),阳新统包含四个三级层序(SQ²⁰到SQ²³),乐平统包括两个三级层序(SQ²⁴和SQ²⁵)。在层序地层框架内,系列古地理图和系列层序地层格架栅状图较为系统地反映了研究区二叠纪复杂而有序的时间和空间相变特征。主要的时间相变面即形成层序界面,具有明显的“跳相”和地层间断现象,由于在不同地点间断的时限不一致而造成“间断面穿时”;沉积环境的空间变化,以及伴随着时间变化中的相带迁移所造成的空间相变,其相应的相变面总是斜交时间面而造成“相变面穿时”;不同沉积阶段的层序具有不同的相序组构,并在空间上形成有序的变化,从而代表了不同的古地理背景。因此,层序地层研究的核心内容是“沉积物的时间演变序列和沉积相的空间展布形式所代表的规律性”,结合生物地层特征,这种规律性本身也可以作为地层划分和对比的标志。  相似文献   

小区域景观的三维可视化     

王猛  田丰 《地理空间信息》2012,(3):94-96

现实世界的复杂性决定了其在计算机中表达的复杂性,三维模型的构建成为3DGIS中亟待解决的一个核心问题。探讨了三维建模思想以及建模方法,并以ArcGIS和SketchUp交互建模方法为例,论述了三维建模流程以及注意事项,通过模型库的构建,提高了该方法在小区域内景观的三维快速构建效率,所得的模型为3DGIS提供了数据源。实践表明,在有限的经济、技术等条件下,该方法具有较强的可行性和实用性。  相似文献   

TIN向规则格网DEM转换的新算法     

张春亢  沙晋明  钟新科 《地理空间信息》2012,(2):122-124

由TIN生成规则格网DEM是基于TIN的离散点数据栅格化的重要一步,在基于一种数学原理的基础上运用逆向思维提出了TIN向规则格网DEM转换的新算法,不用传统的分块和建立索引,而是通过逐个遍历三角形来判断格网节点位于哪一个三角形中并实现格网节点的插值。通过编程实现、测试该算法,证明它具有非常高的插值效率。  相似文献   

京津唐城市群不透水地表增长对水环境的影响(英文)   总被引：5，自引：1，他引：4  

匡文慧 《地理学报(英文版)》2012,22(3):535-547

The impervious surface area (ISA) at the regional scale is one of the important en-vironmental factors for examining the interaction and mechanism of Land Use/Cover Change (LUCC)-ecosystem processes-climate change under the interactions of urbanization and global environmental change. Timely and accurate extraction of ISA from remotely sensed data at the regional scale is challenging. This study explored the ISA extraction based on MODIS and DMSP-OLS data and the incorporation of China’s land use/cover data. ISA datasets in Beijing-Tianjin-Tangshan Metropolitan Area (BTTMA) in 2000 and 2008 at a spa-tial resolution of 250 m were developed, their spatiotemporal changes were analyzed, and their impacts on water quality were then evaluated. The results indicated that ISA in BTTMA increased rapidly along urban fringe, transportation corridors and coastal belt both in intensity and extents from 2000 to 2008. Three cities (Tangshan, Langfang and Qinhuangdao) in Hebei Province had higher ISA growth rates than Beijing due to the pressure of population-re?sour?ces-envi?ronments in the city resulting in increasingly transferring industries to the nearby areas. The dense ISA distribution in BTTMA has serious impacts on water quality in the Haihe River watershed. Meanwhile, the proportion of ISA in sub-watersheds has significantly linear relationships with the densities of river COD and NH3-N.  相似文献   

中国草原牧区和半牧区草畜平衡状况监测与评价   总被引：7，自引：0，他引：7  

徐斌  杨秀春  金云翔  王道龙  杨智  李金亚  刘海启  于海达  马海龙 《地理研究》2012,31(11):1998-2006

草原超载过牧是造成我国草原大面积退化、沙化的主要原因之一,草畜平衡监测、评价和管理是实现我国草原植被恢复和重建的关键,也是研究的热点和难点。本文采用遥感和地面调查相结合的方法从宏观上监测和评价了农业部认定的264个牧区和半牧区县的草畜平衡状况,主要结论如下:(1)2008年监测区平均草畜平衡指数为33.58%,总体处于超载状态;(2)120个牧区县草畜平衡指数为27.37%,144个半牧业县为42.07%,半牧区县是我国实行草畜平衡管理的重点和难点;(3)六大牧区中牧区县2008年超载程度排序为:甘肃>四川>新疆>青海>西藏>内蒙古,半牧区县超载程度排序为青海>西藏>内蒙古>新疆>四川>甘肃。本文所得结论可为我国草原资源管理和保护提供参考价值和借鉴意义。  相似文献   

旅游干扰对五台山植被景观区植物多样性的影响          下载免费PDF全文

程占红  赵蒙 《干旱区地理》2012,35(4):578-586

 物种多样性是衡量景区生态环境质量的重要指标之一。通过计算物种的多样性指数、科属、区系、生活型和生态型特征,利用除趋势对应分析方法对五台山旅游干扰下植物多样性的格局进行了研究,结果表明：在不同地理因子和物种多样性的作用下,各类植被景观区表现出一定的格局规律。在排序图上,以灌木层和草本层植物为主的Ⅲ区、Ⅳ区和Ⅶ区位于左侧,以乔木层、灌木层和草本层植物为主的Ⅰ区、Ⅱ区、Ⅵ区和Ⅴ区位于中间,仅有乔木层的Ⅸ区位于右侧。坡位、海拔和旅游影响系数与DCA第一轴和第二轴的相关性均较大,说明这3个因子对植物多样性的格局有重要影响。研究结果有益于五台山景区的生态管理。  相似文献   

Building a bioregion through transboundary conservation in Central America     

《Norsk geografisk tidsskrift. Norwegian journal of geography》2012,66(5):265-276

Barquet, K. 2015. Building a bioregion through transboundary conservation in Central America. Norsk Geografisk Tidsskrift–Norwegian Journal of Geography. Vol. 69, 265–276. ISSN 0029-1951.

Proponents of transboundary conservation argue for the formation of a bioregional scale of governance. How such rescaling should be done remains an undiscussed issue. Through a study of the Mesoamerican Biological Corridor in Central America and Si-A-Paz, a transboundary protected area in Nicaragua and Costa Rica, the author investigates how a transboundary scale of conservation is enacted. The study shows that in order to meet the conditions of a bioregion, actors involved in transboundary conservation in Central America produced accounts of social and ecological integrity that did not entirely match local narratives. Moreover, transboundary conservation provided actors with increased mobility across governance scales and sources of funding. In turn, this scalar mobility enhanced the power of already powerful actors in the area, helped states to attract international sources of funding, and empowered previously marginalized local groups at the expense of others. The author concludes that actors involved in transboundary conservation attempt to create new meanings of nature and understandings of society in order to produce a new scale of conservation. However, the study highlights the problems of matching discourses of nature to accounts of social unity, and underlines the political nature of scalar projects.  相似文献   

Outside the boundary - Land use changes in the surroundings of urban nature reserves     

S. Borgström  S.A.O. CousinsR. Lindborg 《Applied geography (Sevenoaks, England)》2012,32(2):350-359

The importance of the landscape surrounding a protected area for sustaining its values is frequently discussed in conservation literature. Studies on the interactions of urbanisation and nature conservation at the global scale suggest that protected nature attracts urbanisation, and that this in turn might negatively impact the area. However, studies specifically addressing such land use dynamics at city scale are largely missing. In this study we examine the change in proportion of built up area in two zones (500 m and 1000 m) surrounding 15 urban nature reserves in southern Sweden. By using comprehensive maps from the last 50 years, we compared the zones to the overall urbanisation in the cities to reveal discrepancies in land use surrounding the nature reserves. We found that the amount of built up area in the buffer zones surrounding nature reserves followed the same trend as the corresponding cities and this relation was stable over time, although the positive relationship was not significant. The establishment of nature reserves had no detectable effect on surrounding land use, however two distinguished groups of reserves were identified with either more or less built up area in buffers zones compared to cities. These differences were related to specific local drivers such as land ownership, land use history and nature reserve location. In contrast to earlier studies at global scale, our study did not show that nature reserves attract urbanisation. Instead, we stress that the great variety of contextual factors at the city scale makes quantitative analysis of this kind extremely difficult. However, a general neglect from planning and nature conservation agencies to recognise nature reserves’ dependence on the surrounding landscape configuration could be detrimental to sustain their values in the long-term. Hence we suggest that zones surrounding nature-protected areas should be planned and managed according to local land use history and current landscape conditions to enable and enhance necessary cross-boundary interactions.  相似文献   

中国乡村长寿现象与人居环境研究——以湖北钟祥为例   总被引：2，自引：0，他引：2  

马婧婧  曾菊新 《地理研究》2012,31(3):450-460

乡村长寿现象与人居环境的关系,是地理学与相关学科关注的课题。本文基于人文地理学与人居科学、环境科学和乡村社会等多学科视野,根据世界长寿之乡和中国百岁老人的分布规律,阐述了乡村长寿现象的涵义,分析了客观存在的乡村长寿现象及其成因。同时,以湖北钟祥为案例,运用模糊评价法、综合评价法和比较研究法,系统考究了乡村长寿现象与优越自然生态环境、和谐人文社会环境以及舒适人工居住环境的关系,归纳了乡村长寿现象的客观必然性和成因的综合性、长寿与人居环境的正相关性、山区与平原乡村长寿现象的同质性以及人类诉求健康长寿的永恒性等五个可供思考的重要命题,并对建设有利于"居民健康长寿"的乡村人居环境提出了相关政策建议。  相似文献