Application of MODFLOW and geographic information system to groundwater flow simulation in North China Plain, China

MODFLOW is a groundwater modeling program. It can be compiled and remedied according to the practical applications. Because of its structure and fixed data format, MODFLOW can be integrated with Geographic Information Systems (GIS) technology for water resource management. The North China Plain (NCP), which is the politic, economic and cultural center of China, is facing with water resources shortage and water pollution. Groundwater is the main water resource for industrial, agricultural and domestic usage. It is necessary to evaluate the groundwater resources of the NCP as an entire aquifer system. With the development of computer and internet information technology it is also necessary to integrate the groundwater model with the GIS technology. Because the geological and hydrogeological data in the NCP was mainly in MAPGIS format, the powerful function of GIS of disposing of and analyzing spatial data and computer languages such as Visual C and Visual Basic were used to define the relationship between the original data and model data. After analyzing the geological and hydrogeological conditions of the NCP, the groundwater flow numerical simulation modeling was constructed with MODFLOW. On the basis of GIS, a dynamic evaluation system for groundwater resources under the internet circumstance was completed. During the process of constructing the groundwater model, a water budget was analyzed, which showed a negative budget in the NCP. The simulation period was from 1 January 2002 to 31 December 2003. During this period, the total recharge of the groundwater system was 49,374 × 10⁶ m³ and the total discharge was 56,530 × 10⁶ m³ the budget deficit was −7,156 × 10⁶ m³. In this integrated system, the original data including graphs and attribution data could be stored in the database. When the process of evaluating and predicting groundwater flow was started, these data were transformed into files that the core program of MODFLOW could read. The calculated water level and drawdown could be displayed and reviewed online.     

基于PDA的测量机器人自动化网观测软件研究

分析了自动化网观测软件的具体开发过程,介绍了软件系统所实现的主要功能,获得了可靠的观测数据.     

数字摄像能见度观测系统中实用黑体技术的应用

在数字摄像能见度观测系统 (DPVS) 中, 目标物的自身亮度难以实时测量, 给观测结果带来的不确定性不可忽略, 采用实用黑体技术可以大大减小乃至消除其造成的误差。作者对非黑体目标引起的测量误差进行了分析, 结果表明相对误差随着目标物反射率的增加和能见度的升高而增大, 为了保证测量精度, 需要采用反射率足够低的目标物。对于长方体结构的实用黑体腔, 采用多次反射法计算了其近轴向的半球-方向反射率与其特性参数之间的关系。在没有观测到侧壁的前提下, 其轴向反射率最大, 随着偏离轴线角度的增加, 反射率逐渐减小。轴向反射率随腔体长度与开口边长比值的增加而迅速减小, 而腔体宽度增加引起的变化不明显。另外, 作者还推导了在考虑弥散成像时对实用黑体开口尺寸最小需求的计算公式, 也给出了符合一定条件的实用黑体轴向反射率的近似计算公式, 从而提供了DPVS中实用黑体参数选择的基本原则。最后, 给出了DPVS采用非黑体和实用黑体目标计算能见度的对比试验结果, 充分说明了在DPVS中采用实用黑体技术的必要性和可行性。     

电视天气预报节目中视频音频同步问题探讨

国家广电总局把2004年定为数字发展年、产业发展年，树立了科学发展观，全面推进我国广播影视向现代化媒体的转变。新世纪、新阶段、新要求、新技术给我们的社会带来了新的变化。随着人民群众生活水平的不断提高，人们对精神文化需求呈现出新的特点：选择的范围大大扩展，消费的能力大大增     

高建筑对周围建筑雷击保护距离的模拟

在已有先导连接参数化方案的基础上,选取近地面层为研究区域,保持方案中其他基本参量不变,通过改变闪电的空间形态,在同一建筑分布的背景下进行多次闪电模拟。研究多个建筑之间的屏蔽作用以及建筑雷击保护距离与建筑相关特征参数之间的关系,结果表明:高建筑对矮建筑具有屏蔽作用,并存在一个临界保护距离,当高、矮建筑高度分别为190 m和165 m,宽度均为20 m时,建筑之间的距离在12 m以内,矮建筑受高建筑完全保护不遭受雷击;建筑之间的距离超过12 m,矮建筑遭雷击次数明显增多。     

胶东型金矿：与壳源重熔层状花岗岩和壳幔混合花岗闪长岩有关的金矿

胶东型金矿是与壳源重熔形成的层状岩浆活动和壳幔混合岩浆活动有关的金矿床,由于成矿时所处构造位置和容矿构造不同而表现为不同的类型,涵盖破碎带蚀变岩型、石英脉型等胶东地区所有金矿床类型。玲珑花岗岩是壳源物质长期处于高温高压下且熔融形成的多物质来源层状岩体,其析出的高温碱性热液溶解金等成矿物质形成初始含矿热液。岩体抬升过程中在其边部往往容易形成拆离带,在岩体中形成脆性断裂构造,均为成矿结构面。后期壳幔混合成因的郭家岭花岗闪长岩,侵入于玲珑层状花岗岩中并一起隆升,使郭家岭花岗闪长岩附近区域的成矿结构面进一步扩大,矿液浓度进一步增大,当上升到特定深度时形成金矿体。玲珑花岗岩和郭家岭花岗闪长岩共同构成成矿地质体,重熔的玲珑层状岩体是成矿基础地质体,郭家岭花岗闪长岩加强了金矿的成矿作用。该认识对开辟胶东新的找矿思路和找矿靶区有很好的指导作用,据此初步预测新的大型拆离带是金矿集中成矿区域,可能成为将来有望取得重大突破的矿集区。     

Early Cretaceous Climate Changes Recorded in Magnetic Susceptibility and Color Index Variations of the Lower Liupanshan Group, Central China

This study carried out comprehensive analysis on sedimentology, magnetic susceptibility(χlf) and color data of the continental sediments of the Liupanshan Group in Central China so as to obtain climatic change information during the 129.14–122.98 Ma interval. Based on the results of the ?lf and of the redness(a*), the section can be divided into two segments:(1) 129.14–126.3 Ma, with the lowest ?lf values and strongly variable relatively high values of redness and(2) 126.3–122.98 Ma, with high ?lf values and relatively low redness. Analysis of the lithology and facies as well as the magnetic minerals and their contents points to a detrital origin of the magnetic minerals and this allow us to interpret the relationship between magnetic susceptibility variations and climate changes. Our study shows that the climate was significantly dry and hot during the whole studied interval although the interval between 126.3 Ma and 122.98 was a little bit cooler with increased humidity.     

A review on missing hydrological data processing

Like almost all fields of science, hydrology has benefited to a large extent from the tremendous improvements in scientific instruments that are able to collect long-time data series and an increase in available computational power and storage capabilities over the last decades. Many model applications and statistical analyses (e.g., extreme value analysis) are based on these time series. Consequently, the quality and the completeness of these time series are essential. Preprocessing of raw data sets by filling data gaps is thus a necessary procedure. Several interpolation techniques with different complexity are available ranging from rather simple to extremely challenging approaches. In this paper, various imputation methods available to the hydrological researchers are reviewed with regard to their suitability for filling gaps in the context of solving hydrological questions. The methodological approaches include arithmetic mean imputation, principal component analysis, regression-based methods and multiple imputation methods. In particular, autoregressive conditional heteroscedasticity (ARCH) models which originate from finance and econometrics will be discussed regarding their applicability to data series characterized by non-constant volatility and heteroscedasticity in hydrological contexts. The review shows that methodological advances driven by other fields of research bear relevance for a more intensive use of these methods in hydrology. Up to now, the hydrological community has paid little attention to the imputation ability of time series models in general and ARCH models in particular.     

生态地质研究进展与展望

生态地质学是研究生态系统与地质环境之间关系的一门交叉学科,对国土空间生态保护修复工作有重要理论支撑作用。我国生态地质研究工作虽然经过了多年的发展与积淀,但时至今日生态地质学仍然处于研究和探索阶段。鉴于此,基于前人的大量研究,总结了国内外生态地质研究进展: 国际上,俄罗斯建立了生态地质学研究体系,美国发起的地球关键带研究是与生态地质研究十分契合的主题; 在国内,生态地质研究主要着眼于”生态-地质”相互作用过程与机理以及地质环境影响下的系统性生态修复研究。在此基础上,提出了生态地质学涵义及其研究内容、方法技术创新及学科体系构建思路,以期为服务山水林田湖草沙整体保护、系统修复、综合治理和生态地质系统深化研究提供借鉴。     

基于ComGIS的校园导航系统

分析了ComGIS的特点,并结合其特点,利用VisualBasic6.0,SuperMap和SQLServer2000等软件实现了校园导航系统的空间数据和属性数据的存储、可视化查询、测量地图等,同时介绍了系统空间数据库和空间地理模型的建立,以及在系统的设计中所涉及到的多媒体等技术。