一种时空数据静态可视化表达方法

本文简要介绍了时空数据可视化的必要性,以及目前人们采用的时空数据可视化方法,并分析了这些方法的局限性,提出了一种将年轮(annual ring)作为时空载体,结合视觉变量对面状地物的属性数据进行静态可视化的方法。该方法将面状地物的同心环按照类似树木年轮的生长特征进行划分,作为空间和时间的载体,不同时期属性数据映射到相应的同心环中,同心环的厚度和色彩的差异揭示了属性数据的变化。最后以武汉市城市管理网格化平台的统计评价数据为例实现了对比率量表数据的时态可视化表达。本文所提出的静态时空可视化方法将面状地物的空间、属性和时间紧密地结合在一起,克服了以往静态可视化方法中时间-空间、时间-属性相分离的不足,试验证明了这种方法在实践中的可行性。     

1∶500,1∶1000,1∶2000系列数字化测绘产品的精度目标与实现

1∶500,1∶1000,1∶2000系列数字化测绘产品按其生产工艺和用途的不同其精度规格也不尽相同,但产品的精度状况始终是测绘生产部门与用户所关心的问题。本文列举了现行有关规范的相关精度指标、规格,并结合产品的用途、特点和测绘生产的实际,简要阐述精度目标的控制与实现过程,对测绘实际工作有一定的参考价值。     

苏北盆地泰州组砂岩成岩序列和储集层质量主控因素分析?

基于53口井310余块储集层砂岩样品的分析研究,指出泰州组储集层存在着压实(压溶)、胶结和溶蚀等成岩作用,但在不同位置成岩作用的表现有所不同。海安凹陷以胶结和溶蚀作用为主,压实与压溶作用不太明显;高邮凹陷的压实程度较海安凹陷强烈。压实作用使得高邮凹陷泰州组储集层孔隙度在2 400～2 800 m处于10%左右,而海安凹陷为10%～20%。海安凹陷和高邮凹陷泰州组储集层目前处于中成岩阶段A期。储集层质量主要受原始沉积环境和成岩作用的综合影响。压实作用和胶结作用均可降低孔隙,但当碳酸盐胶结物含量小于15％时,胶结作用对储集层质量影响较小。碳酸盐胶结物和长石颗粒溶蚀形成了大量的粒间溶孔。海安凹陷有利储集层主要分布在西北部和东部三角洲前缘砂体和滑塌浊积扇砂体中,高邮凹陷有利储集层主要分布在南部扇三角洲前缘砂体中。     

葛店矿双庙扩大区三维地震勘探

葛店煤矿双庙扩大区位于豫、皖两省交界处。勘探区为一轴向北北东向的不对称向斜构造,地层倾角26°～30°,测区深部有岩浆岩侵入体,严重影响煤层赋存形态;地表条件复杂,村庄密集、河流较多,测区东侧塌陷区水塘大面积分布．三维地震勘探野外施工难度大。本区地震勘探观测系统设计为12线18炮制,为避免偏移归位及叠加次数降低等问题,在向斜轴部两侧、村子周边及河岸处适当加密炮点,并在塌陷区利用钢钎插置检波器以保证CDP点完整性。数据处理采取了叠前反褶积、叠前时间偏移等技术,数据处理效果显著。遵循多波组对比、多个数据体综合解释的原则,以纵向、横向和任意时间剖面相结合,充分利用三维可视化技术进行地震资料解释。本次勘探成果查明了主采煤层三2^2、二2煤层的构造形态及埋藏深度;解释落差5m以上断层34条,其中修改原有断层5条;另外新发现小于5m的异常断点22个。经巷道验证煤层底板标高误差0．43％～1．96％,巷道已揭露断层7条,与解释成果基本一致。     

煤层气固井声幅测井方法探讨

影响煤层气固井声幅测井的因素较多,如地层软硬变化大、套管内径或壁厚不均、仪器不居中、发射能量不足、接收灵敏度不够等,这些因素的存在将会导致首波丢失、时差曲线产生周波跳跃或波动现象。为提高煤层气固井声幅测井质量,要尽量保证所用仪器外径接近套管内径,以减少无效传播和能量损失,另外需提高仪器的发射能量及接收灵敏度;在自由套管和声波强吸收地层,必须保证自由套管首波不限幅、声波强吸收地层首波不丢失。在现场解释时,一般以＂自由套管＂处的偏转幅度值A为标准,将固井声幅曲线幅度的20%A和40%A作为分界点,评价固井效果。     

第二次土地调查若干问题探讨

第二次土地调查的目的是全面查清全国土地利用状况,掌握真实的土地基础数据,如何保证调查的质量?文章以江阴市为例进行探讨。     

Influence of karst hydrology on water quality management in southeast South Australia

Southeast South Australia has large reserves of potable groundwater, generally close to the surface. European settlement has had a major impact on groundwater quality due to the presence of extensive karst in the unconfined aquifer. Historically, industries such as cheese factories were often sited close to karst features (e.g. caves and sinkholes) because they provided a convenient means of waste disposal. Although most have long since closed, they have left a legacy of pollution plumes of varying sizes. In Mount Gambier, the main regional centre, the presence of both exposed and subterranean karst features provided a perfect system for the disposal of stormwater. Prior to the provision of a sewerage system within Mount Gambier, all toilet and household wastewaters were disposed to ground. These activities and the subsequent problems that began emerging in the 1960s have led to a concerted effort over the last 20 years to change the philosophy of waste disposal and to generate an understanding and responsibility by those who live in the region and depend on groundwater for the major part of their water supply. Mount Gambier's water supply comes from the Blue Lake. Groundwater inflow from a highly karstic Tertiary limestone aquifer provides 90% of the recharge to the Blue Lake. The lake is a high-value resource in a high-risk environment and in order to minimize this risk, a water-quality management plan for the lake is currently being developed.     

An evaluation of residential air radon concentrations and related variables in southeast Michigan,USA

Analysis of 153 residential air radon (Rn-222) screening measurements from southeast Michigan indicates that basements host Rn levels two to three times higher than upper-level rooms. Compared to unfinished basements, finished (e.g., paneled walls, tiled floors) basements apparently reduce indoor air Rn levels while partially finished basements may not. Factor analysis of residence questionnaire data explains 59 percent of the Rn data variance. The volume of pathways (e.g., foundation cracks/holes, uncapped sumps) allowing Rn seepage into the dwelling controls the largest portion, 23 percent, of the explained data variance. The residence water source explains 11 percent of the Rn data variance. Groundwater Rn levels contribute to the air Rn data variability, but the study data cannot quantitatively assess this contribution. Seven percent of the Rn data variance is likely controlled by house depressurization facilitated by residence structural properties. Residences with foundation cracks or poorly sealed joints and low-volume indoor-outdoor air exchange are more prone to this effect. Eighteen percent of the explained Rn data variance correlates with the residence's primary heat source. Evidently, operating combustion sources also induce house depressurization and allow Rn to be drawn into the house through entry paths. Twenty-four percent of the analyses equal or exceed 4 pCi/1 Rn. In residences occupied 5 years by the same individuals, 17 percent of the Rn data are 4 pCi/l; here the arithmetic mean air Rn level is 8.3 pCi/l and the average occupancy period 17.4 years.     

编译BASIC语言编程质量的控制

本文利用编译BASIC语言具有的某些特殊功能,结合具体课题研究实践,从编程技术的模块化、坚固性和可用性三方面进行了实验,采用覆盖技术、“出误陷阱”等技术,使得在较小的内存中运行较大的程序并捕获可能发生的各种随机事件,达到了控制编程质量的目的。     

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。