Web-cam’s potential for collaborative activities in the Earth sciences

We report here our experiences from using easily acquired web-cam components for collaborative ventures in the Earth sciences. We have used a variety of hardware and different software. We demonstrate from various locations in the U.S.A. the feasibility of using web-cam in multitudinous activities, relevant for conducting research and knowledge dissemination. We summarize the quality of the connections from the various combinations of communicating parties. Today, web-cams can be utilized as an economical and viable means of point-to-point communication in the Earth science community. Greater bandwidth is sorely needed for activities such as multi-party conferencing on the present internet network. We propose that web-cam can be readily deployed as a web-service for facilitating collaborative research over the GRID infrastructure, using the middleware Narada-Brokering. Web-cam will play an important role in the emerging field of geoinformatics.     

A microscale model for air pollutant dispersion simulation in urban areas: Presentation of the model and performance over a single building

A microscale air pollutant dispersion model system is developed for emergency response purposes. The model includes a diagnostic wind field model to simulate the wind field and a random-walk air pollutant dispersion model to simulate the pollutant concentration through consideration of the influence of urban buildings. Numerical experiments are designed to evaluate the model's performance, using CEDVAL(Compilation of Experimental Data for Validation of Microscale Dispersion Models) wind tunnel experiment data, including wind fields and air pollutant dispersion around a single building. The results show that the wind model can reproduce the vortexes triggered by urban buildings and the dispersion model simulates the pollutant concentration around buildings well. Typically, the simulation errors come from the determination of the key zones around a building or building cluster. This model has the potential for multiple applications; for example, the prediction of air pollutant dispersion and the evaluation of environmental impacts in emergency situations; urban planning scenarios;and the assessment of microscale air quality in urban areas.     

Impact Assessment of Climate Change and Human Activities on Runoff Variation in Coal Mining Watershed,NW China

Water Resources - The Kuye river watershed is a coal mining watershed in Northwest China. The study analyzed runoff change of year, high flow period and low flow period in the past 60 years based...     

刍议《重庆历史地图集·第一卷古地图》的设计思想

介绍了图集的基本情况及当前编纂出版历史地图集的不足,以此为基础提出了本图集内容选录的特点。重点对《重庆历史地图集·第一卷古地图》中涉及的内容、结构、文字符号化、版式及各元素设计思想作了全面的阐述,并将这些设计思想应用于本图集,取得了较好的效果。最后,总结了图集设计的创新点,为今后其他省市编制相关的图集作参考。     

地理信息系统技术在中小学布局调整中的作用

我国“十五”期间开始中小学布局调整,经过几年的调整,教育条件、教育质量都有所改善,但也带来一些问题,这些问题的根本原因在于缺乏科学预测和规划。地理信息系统技术是利用计算机解决各学科空间问题的学科,它可以在中小学布局中进行科学分析和预测,为中小学布局调整提供决策支持。     

Web-based service of a visualization package “Amira” for the geosciences

Amira is a powerful three-dimensional visualization package that has been employed recently by the science and engineering communities to gain insight into their data. We discuss a new paradigm for the use of Amira in the Earth sciences that relies on the client-server paradigm. We have developed a module called WEB-IS2, which provides web-based access to Amira. This tool allows Earth scientists to manipulate Amira controls remotely and to analyze, render and view large datasets through the Internet without regard for time or location. This could have important ramifications for GRID computing.     

Using hydrological simulation to identify contribution of coal mining to runoff change in the Kuye River Basin,China

Under the influence of all kinds of human activities, runoff decreased significantly in most river basins in China over the past decades. Assessing the effect of specific human activities on runoff is essential not only for understanding the mechanism of hydrological response in the catchment, but also for local water resources management. The Kuye River, the first-order tributary of the middle Yellow River, has experienced significant runoff declines. The coal resources are rich in the Kuye River Basin. In mined out area some cranny changed the hydrogeological conditions of the mining area and the hydrological process of the basin. In this study, the time series of runoff was divided into three periods at two critical years of 1979 and 1999 by precipitation–runoff double accumulation curve. The Yellow River Water Balance Model (YRWBM) is calibrated and verified to a baseline period in 1955–1978. Subsequently, natural runoff for human-induced period (1979 to 1998) and strongly human-induced period (1999 to 2010) is reconstructed using the YRWBM model. The YRWBM model performed well in simulating monthly discharges in the catchment, both Nash Sutcliffe coefficients in calibration and verification were above 70%, while relative errors in both periods were at less than 5%. The percentage of runoff reduction attributing to human activities was from 39.44% in 1979–1998 to 56.50% in 1999–2010. Further the influence of coal mining on river runoff was assessed quantitatively by YRWBM model simulation. The influence of coal mining on runoff reduction was 29.69 mm in 1999–2010 which was about 2.58 × 10⁸ m³/a. It accounted for 71.13% of the runoff reduction during this period. Coal mining became a dominant factor causing the runoff reduction.     

Seismic performance evaluation of typical dampers designed by Chinese building code

Adding dampers is a commonly adopted seismic risk mitigation strategy for modern buildings, and the corresponding design procedure of dampers has been well established by the Chinese Building Code. Even though all types of dampers are designed by the same procedure, actual seismic performance of the building may differ from one to the others. In this study, a nine-story benchmark steel building is established, and three different and typical types of dampers are designed according to the Chinese Building Code to realize structural vibration control under strong earthquake excitation. The seismic response of the prototype building equipped with a viscoelastic damper, viscous damper and buckling-restrained brace(BRB) subjected to 10 earthquake records are calculated, and Incremental Dynamic Analysis(IDA) is performed to describe progressive damage of the structure under increasing earthquake intensity. In the perspective of fragility, it shows that the viscoelastic damper has the highest collapse margin ratio(CMR), and the viscous damper provides the best drift control. Both the BRB and viscoelastic dampers can effectively reduce the floor acceleration responses in the mid-rise building.