Total gaseous mercury emissions from mercury-enriched soil in Guizhou, China

Guizhou is located in the Circum-Pacific Global Mercuriferous Belt, and mercury concentrations in soil in this area are enriched. In-situ total gaseous mercury （TGM） exchange fluxes between air and soil surface were intensively measured at four sampling sites in Guiyang from 21 May to 16 June, 2003, and five sites in the Lanmuchang mercury mining area in December 2002 and May 2003, respectively. The in-situ Hg flux measurement was conducted with a dynamic flux chamber （DFC） of quartz. Overall, net emissions were obtained from all sampling sites. Soil mercury concentration and solar radiation have been proved to be the two most important parameters to control mercury emissions from soil. Meanwhile, rain events can enhance mercury emission rate significantly.     

Heavy metals in freshly deposited sediments of the river Subernarekha, India: an example of lithogenic and anthropogenic effects

Heavy metal distribution patterns in river sediments aid in understanding the exogenic cycling of elements as well as in assessing the effect of anthropogenic influences. In India, the Subernarekha river flows over the Precambrian terrain of the Singhbhum craton in eastern India. The rocks are of an iron ore series and the primary rock types are schist and quartzite. One main tributary, the Kharkhai, flows through granite rocks and subsequently flows through the schist and quartzite layers. The Subernarekha flows through the East Singhbhum district, which is one of India’s industrialised areas known for ore mining, steel production, power generation, cement production and other related activities. Freshly deposited river sediments were collected upstream and downstream the industrial zone. Samples were collected from four locations and analysed in <63-μm sediment fraction for heavy metals including Zn, Pb, Cd and Cu by anodic stripping voltammetry. Enrichment of these elements over and above the local natural concentration level has been calculated and reported. Sediments of the present study are classified by Muller’s geo-accumulation index (I _geo) and vary from element to element and with climatic seasons. During pre-monsoon period the maximum I _geo value for Zn is moderately to highly polluted and for Cu and Pb is moderately polluted, respectively, based on the Muller’s standard. Anthropogenic, lithogenic or cumulative effects of both components are the main reasons for such variations in I _geo values. The basic igneous rock layer through which the river flows or a seasonal rivulet that joins with the main river may be the primary source for lithogenic components.     

紫色丘陵区水土保持林低效化的土壤成因

四川盆地紫色丘陵区的水土保持林低效化问题已较严重。研究了其土壤方面的成因。通过对土壤构造、土壤肥力特性、土壤结构性评价等研究，指出该区人工林地的土壤构造发育不正常，土壤腐殖质胶体积累量低。土壤结构质量差等林地土壤退化是土壤水土保持功能降低的主要原因。根据研究的初步结果，提出了相应的对策建议。     

土壤天然热释光测量在寻找滑坡体边界中的应用研究

土壤天然热释光测量方法是一种累积型测氡方法。由于累积测氡时间长,其灵敏度和异常的重现性远比一般累积测氡及其子体方法好,因此,在地质领域得到了广泛的应用。在寻找滑坡体边界的应用中,取得的测量效果明显,表明该方法经济有效。     

我国西部1∶5万地形图空白区地物解译研究——以西藏那曲其香错地区为例

我国西部部分地区1∶5万地形图数据尚未完成,给区域和国家经济发展带来极大不便。空间技术、计算机技术和信息技术的高速发展为遥感技术应用提供了技术支持,高分辨率影像获取能力的提高为大比例尺地物特征的提取提供了数据可能。本文采用SPOT5遥感影像,以1∶5万地形图图式标准为依据,进行青藏高原其香错地区地物判读,结果表明SPOT5能基本满足1∶5万地形图制图要求。为进一步提高判读结果,可采用多时相、多分辨率影像进行1∶5万地形图地物判读。     

Relationship of Uncertainty and Line Segment for Between Polygon Segment Spatial Data in GIS

The mathematic theory for uncertainty model of line segment are summed up to achieve a general conception, and the line error hand model of εσ is a basic uncertainty model that can depict the line accuracy and quality efficiently while the model of εm and error entropy can be regarded as the supplement of it. The error band model will reflect and describe the influence of line uncertainty on polygon uncertainty. Therefore, the statistical characteristic of the line error is studied deeply by analyzing the probability that the line error falls into a certain range. Moreover, the theory accordance is achieved in the selecting the error buffer for line feature and the error indicator. The relationship of the accuracy of area for a polygon with the error loop for a polygon boundary is deduced and computed.     

甜水海微陆块上二叠系地层的厘定及其特征

笔者在《岔路口》等四幅1：25万区域地质调查工作中，在红山湖一带从前人所划的石炭系地层中解体出一套二叠系地层，并对其进行了详细的岩石地层、生物地层和层序地层研究，拟新命名为红山湖组，时代为中二叠世。该地层为甜水海微陆块上稳定型的碳酸盐岩建造，与陆块南北两侧二叠系特征截然不同。该套地层的发现填补了微陆块上二叠系地层的空白，对古特提斯多岛洋研究具有重要意义。     

西北地区的自然环境类型

自然环境区划是国土规划的重要基础，是自然环境综合特征的基本反映.以西北地区的气候分区、地貌分区、植被分区（生态分区）为基础，将西北地区的自然环境类型划分为5个自然分区：阿尔泰-准噶尔区，塔克拉玛干-毛乌素沙漠区，青藏高原东北缘区，黄土高原区，秦巴山地与汉水谷地区.这5个区有完全不同的自然环境特征和资源优势特征，因而开发对策和环境对策是不同的，应予以分别对待.正确认识各区的自然环境特征，才能实现西北地区社会经济及环境的可持续发展。     

湖南及邻区地壳旋转的可能成因、对大地构造演化的影响及其与大规模成矿作用关系初探

在湖南及邻区,无论从地表的地质构造还是地球物理场上,都表现出明显的环状分布特征。这种特征可能是地壳的旋转运动所造成,它对湖南及邻区大地构造的演化、大规模成矿作用等具有重大的影响。本文对这种旋转运动的可能成因,以及所伴随的一系列地质作用、与大规模成矿作用的关系等进行了初步探讨。     

淮河流域土壤湿度异常的时空分布特征及其与气候异常关系的初步研究

利用中国东部1990~2000年旬平均土壤湿度、降水和气温观测资料，通过对0~50 cm层次土壤湿度进行旋转主分量分析 (REOF)，重点分析了淮河流域土壤湿度的时空分布特征, 并初步研究了土壤湿度与前期、同期和后期不同时段降水与气温的关系。发现春季以30 cm为界，30 cm以上各层土壤湿度异常的第一旋转空间模态十分相似, 其大值中心主要位于淮河流域，而30 cm以下 (30~50 cm) 各层的第二旋转空间模态与之亦十分类似, 因此称该模态为“淮河型”，而夏季和秋季虽然该模态也很显著, 但特征不如春季突出。该模态在各层次土壤中具有明显的持续性特征，均存在40旬左右的显著周期；并与前期和同期降水（气温）呈显著正 (负) 相关关系，与约半年后的降水 (气温) 呈负 (正) 相关关系。