地球化学方法在麻林桥低温热水勘查中的应用

应用地球化学方法是地热、温泉勘查中广泛采用的有效手段之一。以麻林桥低温热水为例，说明土壤中的汞、砷、硼微量元素的富集规律，这些微量元素对寻找地下导热构造有明显的指示作用。     

半微量凯氏法测定土壤全氮量的不确定度评定

以半微量凯氏法测定土壤中全氮量为例，对测定结果的不确定度来源进行了详细分析，对测定过程中的主要不确定度分量进行了合理评定，包括样品和标准物质硼砂的称量引入的不确定度，硼砂的纯度引入的不确定度，容量瓶、移液管和滴定管的体积引入的不确定度．相关元素的摩尔质量引入的不确定度以及测量的重复性引入的不确定度。最后合成标准不确定度．通过乘以95％置信概率下的扩展因子2获得测量结果的扩展不确定度。     

石墨炉原子吸收光谱法测定农业地质调查土壤样品中镉的不确定度评定

用实例对石墨炉原子吸收光谱法测定土壤样品中镉元素的不确定度进行评定,采用《测量不确定度评定与表示指南》对测量结果进行评估。分析了不确定度的主要来源,包括测量浓度的不确定度、体积的不确定度、称量不确定度及测量重复性引起的不确定度。评估了镉含量的合成标准不确定度和扩展不确定度。对于镉含量为0.42×10-6的土壤样品,其扩展不确定度为0.04×10-6。     

云南省岩溶水地球物理探测实践

由于岩溶发育的不均匀性,决定了岩溶水的埋藏分布也具有不均匀的特征,含水层富水性的空间差异极大。岩溶水的不均匀性给岩溶水勘查和开发工作带来了很大的困难,以至于裸露型岩溶石山区的供水勘探孔成井率仍然很低。要有效地发挥岩溶水资源的优     

Dynamic analysis of eco-environmental changes based on remote sensing and geographic information system: an example in Longdong region of the Chinese Loess Plateau

The Chinese Loess Plateau is suffering from severe soil erosion. The eco-environmental changes of the plateau are believed to have an important influence on global eco-environmental sustainability; hence, this problem has attracted considerable attention from scientists around the world. This study has two purposes; application of remote sensing (RS) and geographic information system (GIS) techniques in the dynamic analysis of eco-environmental changes in the semiarid zone; and using the Longdong region of the Chinese Loess Plateau as an example, to make dynamic analysis of the eco-environmental changes of the region during the 1986–2004 period and identify controlling factors. Landsat Thematic Mapper (TM) data at a spatial resolution of 30 m were used for analysis. Two training areas were selected in Jingning and Qingcheng counties for analysis using 10-m resolution SPOT and Landsat TM data. The satellite RS images were obtained from the Institute of Remote Sensing Application (IRSA), Chinese Academy of Sciences (CAS). Each images was rectified by Albers Equal Area Conic projection based on 1:50,000 scale topographic maps after spectrum preparation of the images. To make the precision within 1 or 2 pixels, the accurate coordinative control points of the two systems were identified. Then the interpretation key was established based on the land use/cover survey in the study area. The images were classified into six primary environmental types (farmland, forest, grassland, water, construction area, and desert) and 25 sub-types using a visual image interactive interpretation method to obtain vector and attribute data. The resultant accuracy of the land use/cover classification reached 95%. Finally, the transformation areas and ratios of various eco-environmental types in the region were calculated to obtain the transition matrixes of eco-environmental types in the two training areas, Jingning and Qingcheng. This study demonstrates that satellite RS and GIS techniques are effective tools to monitor and analyze the eco-environmental changes in the semiarid region. Visual image interactive interpretation based on GIS technique provides comprehensive information on the direction, rate, and location of eco-environmental changes. The transition matrix model can be used to precisely analyze the variation and rates of the eco-environmental types and their spatial distribution. Great land use changes have taken place Longdong during the 1986–2004 period. These eco-environmental changes were driven by natural and human factors. Natural factors influencing the Longdong region of the Chinese Loess Plateau mainly include temperature, water condition, terrain, soil, and erosion; while human activities include over-cultivation, overgrazing, and fuelwood cutting. As viewed from the extent and severity of the influences, human activities play a very important role in altering the eco-environment of the semiarid region. The study results indicate a need for future research and observation in the semiarid region.     

电磁感应仪EM38用于土壤盐渍剖面分类与评价研究

结合电磁感应仪EM38测量与田间采样,文章分析了黄河三角洲典型区域土壤电导率的剖面分布特征,建立了磁感式表观电导率与土壤电导率间的(多元)回归解译模型,探讨了不同分类方法对土壤盐渍剖面分类结果的准确性,并对典型盐渍剖面类型进行了评价。结果表明:研究区土壤盐分具有较强的表聚性与变异强度;土壤电导率与磁感表观电导率EMh、EMv间呈极显著的相关关系,EMh对浅层土壤电导率的解译精度较高,而EMv对深层土壤电导率的解译精度较高;EMv/EMh法和理论函数法对土壤盐渍剖面的分类结果均具有较高的精度,且理论函数法分类结果的准确性明显优于EMv/EMh法;研究区土壤盐渍剖面可划分为表聚型、底聚型与均匀型,在数量上以表聚型及底聚型为主,其中表聚型与均匀型属于积盐型剖面,底聚型属于脱盐型剖面。该结果对研究黄河三角洲地区土壤盐渍化的发生、机理、预测与评估该地区土壤盐渍化的发生、发展具有重要意义。     

中国优质环保型炼焦煤的评价及资源量等级

我国炼焦煤资源丰富，但优质炼焦煤一直处于短缺局面。根据全国已有煤质数据分析，从优质（主要考虑挥发分指标）、环保（主要考虑硫分和灰分指标）两个方面结合有害微量元素含量，将炼焦煤划分为四种类型，确定了优质环保型炼焦煤资源的评价步骤，对全国五个赋煤区优质环保型炼焦煤的资源量等级进行了统计分析。     

Vulnerability assessment in a volcanic risk evaluation in Central Mexico through a multi-criteria-GIS approach

The Valley of Toluca is a major industrial and agricultural area in Central Mexico, especially the City of Toluca, the capital of The State of Mexico. The Nevado de Toluca volcano is located to the southwest of The Toluca Basin. Results obtained from the vulnerability assessment phase of the study area (5,040 km² and 42 municipalities) are presented here as a part of a comprehensive volcanic risk assessment of The Toluca Basin. Information has been gathered and processed at a municipal level including thematic maps at 1:250,000 scale. A database has been built, classified and analyzed within a GIS environment; additionally, a Multi-Criteria Evaluation (MCE) approach was applied as an aid for the decision-making process. Cartographic results were five vulnerability maps: (1) Total Population, (2) Land Use/Cover, (3) Infrastructure, (4) Economic Units and (5) Total Vulnerability. Our main results suggest that the Toluca and Tianguistenco urban and industrial areas, to the north and northeast of The Valley of Toluca, are the most vulnerable areas, for their high concentration of population, infrastructure, economic activity, and exposure to volcanic events.     

气象灾害事件的数学形态学特征及空间表现

几何面特征是气象灾害的主要空间形态表现, 气象要素值的同化结果、下垫面地表类型、人口和财产的聚集特征组合在灾害特征面上的分布情况呈现显著空间差异及分布不均衡。利用空间分析和数学形态学方法, 依据城市地区复杂下垫面所表现的地表土地覆盖类型, 生成数字化动态卷积模板, 对建立在气象要素分布图上的图谱化网格进行动态膨胀和腐蚀操作, 计算结果可图形化表示为气象灾害在城市空间面上的影响图谱, 并以此作为气象灾害在城市地区造成影响的空间评估结果。针对北京1999年7月22日的高温灾害性天气的个例研究结果表明, 靠近或包含“水体”和“绿地”的空间网格区域大多被执行了腐蚀操作, 而建筑用地、道路、水泥地面等分布较集中区域的空间网格, 则被执行了膨胀操作。因此, 采用数学形态学的“面状灾害事件”空间形态特征的演算对表现灾害自然强度及评估多致灾因子下灾害的真实影响情况是非常有效的。     

任意色阶区间精细选区创建方法初探

在通道中利用“阂值”命令创建选择X-255。在通道混合中创建任意色阶区间选择X1～X2。利用通道混合“减去”模式中“缩放”“补偿值”实现深度自由选择。