Geochemistry and environmental effect of cadmium in the super-large Jinding Pb-Zn deposit,Yunnan Province,China

The Jinding Pb-Zn deposit in Yunnan Province is the representative of a Cd-enriched area and mining activities lead to the release of Cd into the hypergenic ecosystem, resulting in Cd pollution. The concentrations of Cd vary greatly from one type to another type of rocks in the mining district. In the host rock, Cd concentrations range from 50×10^-6 to 650×10^-6 with an average of 310×10^-6. In primary ores, Cd concentrations range from 14×10^-6 to 2800×10^-6 with an average of 767×10^-6. However, in oxidized ores, Cd concentrations are highest, varying within the range of 110×10^-6 to 8200×10^-6 , averaging 1661×10^-6. It is shown that the oxidized ores are the main carder and environmental source of Cd. Leaching test showed that Pb/Zn ores are easy to oxidize and thereafter release Cd and other harmful elements. These leached elements in the leachate may be precipitated rapidly in the order of Zn〉Pb〉Cd. As for the concentration distribution of Cd in the Bijiang River, it is estimated to be 15.7 μg/L Cd in water, 49.3 mg/L in suspended substances, and 203.7 mg/L in sediments. The average value of Cd in soil from the polluted area is 83.0 mg/kg. Natural weathering of Cd-rich rocks and minerals imposes a potential environmental risk on the aquatic ecosystem of the Bijiang catchment.     

Environmental Investigation and Evaluation of Land Subsidence in the Datong Coalfield Based on InSAR Technology

Heavy mining of Jurassic and Carboniferous horizontal coal seams in the Datong coalfield has seriously affected the local geological environment, which is mainly manifested by such geohazards as soil avalanches, landslides, mudflows, surface subsidence, surface cracks, surface solid waste accumulation and surface deformation. More seriously, coal mining causes groundwater to leak. Overpumping of groundwater has resulted in substantial land subsidence of the urban area in Datong City. Based on the previous geo-environmental investigation in the work area, the authors used radar remote sensing techniques such as InSAR （synthetic aperture radar interferometry） and D-InSAR （differential synthetic aperture radar interferometry）, supplemented by the optical remote sensing method, for geo-environmental investigation to ascertain the geo-environmental background of the Datong Jurassic and Carboniferous-Permian coalfield and evaluate the effects of the geohazards, thus providing a basis for the geo-environmental protection, geohazard control and prevention, land improvement and optimization of the human environment. In this study 8 cog-nominal ERS-1/2 SAR data frames during 1992 to 2003 were used, but the following processing was made： （1） the multitemporal SAR magnitude images were used to interpret the geological structure, vegetation, microgeomorphology and drainage system; （2） the multi-temporal InSAR coherent images were used to make a classification of surface features and evaluate the coherence change due to coal mining; and （3） the multi-temporal cog-nominal SAR images were used to complete D-InSAR processing to remove the information of differential deformation areas （sites）. In the end, a ten-year time series of differential interferograms were obtained using the multi-temporal cog-nominal SAR images. In the tests, 84 deformed areas （sites） were obtained, belonging to those in 1993-1996, 1996-1997, 1997-1998, 1998-2001, 1998-2002 and 2001-2003 respectively. Of the 84 areas, 44 are m     

合肥市膨胀土试验研究

主要介绍合肥市二环路用生石灰,石膏改良膨胀土的室内试验研究,并根据试验资料说明生石灰、石膏改良膨胀土的效果。同时提出一种用生石灰一石膏改良合肥膨胀土的最佳配方。大量的试验结果表明,用该配方改良后的膨胀土其单轴抗压强度,水中稳定性、耐久性都有显著提高。经十几年来在合肥市二环路上应用效果良好。     

建立现代测绘成果管理机制的探讨

测绘资料和测绘成果的管理,是新时期国家赋予测绘主管部门的重要职责,是我国信息产业的重要组成部分。建立现代测绘成果管理机制,将测绘成果纳入信息化管理系统,最大限度地发挥地理信息资源的潜在价值,将为建设大而强、富而美的新山东提供优质高效的测绘保障服务。     

临港新城地质特征及其对新城规划与建设的影响分析

结合临港新城三维地质调查所取得的成果,分析了该城区地质特征及对新城建设的影响,为新城规划建设提供科学依据和服务。     

江西省九岭区地质灾害危险性区划

对九岭区地质灾害发育的基本特征及其地质环境条件进行了概述,并对其形成条件进行了相关性分析;通过对地质灾害发育的基本规律、控制因素、触发因素与地质灾害关系的分析,采用环境地质学原理,建立区域地质灾害空间预测模型,圈定九岭区地质灾害的危险性分区,为实时地质灾害时间预警预报圈定有效的空间靶区。预测单元采用规则的栅格(500m×500m),共14415个单元;评价指标主要包括地形地貌、工程地质岩类、地质构造、破坏地质环境人类工程活动等四大类26个因子;利用GIS技术,提取出相关的数据信息;信息量预测方程:Ii=-1.164X1-0.999X2-0.681X3 …… 0.203X25-0.135X26(其中X1、X2、X3、…X26取1或0,即某单元中存在某种因素时取1、否则取0),据此计算出各单元格的信息量;根据地质灾害危险性分区临界指标,确定单元格的地质灾害危险性等级;合并同类项,并考虑类似的地质、自然环境具有类似的地质灾害问题的原则,进行归并与单元边界线的修改,得出九岭区地质灾害危险性分区。     

Hierarchical decomposition of variance with applications in environmental mapping based on satellite images

A quadtree-based image segmentation procedure (HQ) is presented to map complex environmental conditions. It applies a hierarchical nested analysis of variance within the framework of multiresolution wavelet approximation. The procedure leads to an optimal solution for determining mapping units based on spatial variability with constraints on the arrangement and shape of the units. Linkages to geostatisiics are pointed out, but the HQ decomposition algorithm does not require any homogeneity criteria. The computer implementation can be parameterized by either the number of required mapping units or the maximum within-unit variance, or it can provide a spectrum of significances of nested ANOVA. The detailed mathematical background and methodology is illustrated by a salt-affected grassland mapping study (Hortobágy, Hungary), where heterogeneous environmental characteristics have been sampled and predicted based on remotely sensed images using these principles.     

南极长城站地区现代环境地球化学特征

本文通过环境背景值、风化壳地球化学、对流层(大气气溶胶)地球化学和人为地球化学异常,初步探讨了南极长城站地区的现代环境地球化学特征。分析表明:环境要素固有的地球化学性质、区域环境条件和自然环境演变之间具有深刻的内在联系。     

岩溶区集中式饮用水源地水质评价与保护——以毕节市倒天河水库和利民水库为例

采用SPSS软件，对2003年01月至2004年12月期间，倒天河水库和利民水库逐月水质监测数据进行数理统计分析，结果表明毕节市饮用水水质污染有较明显的季节变化和空间差异；且不同污染物对水体污染的贡献率各不相同，总磷和粪大肠菌群所占份额最大，方差累积贡献率达77％。在此基础上，利用加权综合污染指数对水体水质污染现状进行综合评价，结果显示倒天河水库和利民水库，水质污染总体较轻．饮用水水质符合《地表水环境质量标准（GB3838—2002）》中Ⅲ类水质标准；最后提出加大水环境保护的建议。