Coupled 2D Hydrodynamic and Sediment Transport Modeling of Megaflood due to Glacier Dam-break in Altai Mountains,Southern Siberia

One of the largest known megafloods on earth resulted from a glacier dam-break,which occurred during the Late Quaternary in the Altai Mountains in Southern Siberia.Computational modeling is one of the viable approaches to enhancing the understanding of the flood events.The computational domain of this flood is over 9460 km2 and about 3.784 × 106 cells are involved as a 50 m × 50 m mesh is used,which necessitates a computationally efficient model.Here the Open MP(Open Multiprocessing) technique is adopted to parallelize the code of a coupled 2D hydrodynamic and sediment transport model.It is shown that the computational efficiency is enhanced by over 80% due to the parallelization.The floods over both fixed and mobile beds are well reproduced with specified discharge hydrographs at the dam site.Qualitatively,backwater effects during the flood are resolved at the bifurcation between the Chuja and Katun rivers.Quantitatively,the computed maximum stage and thalweg are physically consistent with the field data of the bars and deposits.The effects of sediment transport and morphological evolution on the flood are considerable.Sensitivity analyses indicate that the impact of the peak discharge is significant,whilst those of the Manningroughness,medium sediment size and shape of the inlet discharge hydrograph are marginal.     

地震应急响应系统设计与实现

文章应用开源GIS软件OpenScales、GeoServer、PostGIS/PostgreSQL等,以震区基础地理信息数据和地震基本参数作为数据源,构建了基于开源GIS软件的地震应急响应系统.系统在获得地震基本参数之后快速计算地震烈度分布,通过烈度分布分析地震影响区域的道路损毁情况和防护目标、危险源的分布,同时为决策者提供最佳救援线路,可以对救援物资和救援力量进行态势标绘,为应急指挥决策和救援行动提供有效的支持.     

Towards a National Atlas of the Netherlands as part of the National Spatial Data Infrastructure

Abstract

This paper is about different worlds, and how we try to unite them. One of these worlds is the world of National Atlases: collections of complex, high-quality maps presenting a nation to the geographically interested. The second is the world of National Spatial Infrastructures: highly organized, standardized and institutionalized large collections of spatial data and services. In the paper, we describe the two worlds and their fundamental differences and we present the theoretical framework in which these worlds could be united. We introduce a test bed we are using to try out the theoretical framework in a real-life use case. In the architecture of that test bed, we introduce a National Atlas Services layer and describe how we have created an Atlas Map Viewer component, using the Open Web Platform. We conclude by commenting on the results thus far and taking a look into future developments.     

HydrIS: An open source GIS decision support system for groundwater management (Morocco)

A regional groundwater management system has been elaborated, integrating Relational Database Management System (RDBMS) and various web services. It consists of web geospatial application so-called HydrIS (Hydrogeological Information System) based on Open Source components and technologies, leading to a feasible and low-cost solution. Therefore, HydrIS permits delivery of data from a number of heterogeneous sources to standards supported by the Open Geospatial Consortium (OGC). The protocols used for exchanging data are also derived from OGC standards, i.e., WMS (Web Mapping Service), WFS (Web Feature Service), and WCS (Web Coverage Service). Finally, a geoportal was developed, which consists of client-applications that communicate with different Web Services (WMS, WCS, and WFS) through http-requests.     

On open cluster physical parameters from 2MASS data

The near infrared range has opened a new window to study stellar populations in the Galaxy, in the Local Groud and beyond. Despite the large and growing use of these data, insufficient efforts have been made in the direction to calibrate stellar physical parameters such as age, reddening and distance. This can also be achieved using near infrared and optical data together. Furthermore, the huge amounts of photometric data available now and in the incoming years, demand the development of automated and statistical isochrone fittings to cope with such data. With this in mind, we analyse 2MASS data in order to determine physical parameters for a sample of 9 open clusters. As a first step, we determined the age, reddening and distance values for each cluster applying the classical isochrone fitting (by eye). Subsequently, we employed an automated procedure which compares synthetic colour-magnitude diagrams to observed ones, making use of the likelihood statistics to find the best solution. We also carried out structural analyses of the clusters using stellar radial density profiles. Both classical and statistical isochrone fittings revealed that there can be disagreement between physical parameters obtained from near infrared data analysis and the literature corresponding ones, most based on optical and UV data. Concerning the observed cluster structures, they were studied for the first time. We found evidence of various dynamical stages in the sample.     

Trends in the global market for crews: A case study

The starting point is an analysis of the evolution of recruitment of crews in the maritime traffic on the global and local scale; a case study in a medium-size port of the European Union, the Port of the Bay of Cadiz, is presented. The evolution of the Open Registries and the phenomenon of the globalization of crewing have been studied from the information provided in the databases of consultants and international bodies. For the case study an analysis has been made of 507 vessels that docked in the port of Cadiz between the years 2002 and 2008. From this analysis, it is concluded both globally and locally that market is evolving rapidly. The question of finding suitable crews is not only economic: sometimes the reasons for these “substitutions” are directly related to the demands in terms of working hours or civilized conditions of accommodation and food. Multiculturality is therefore a general feature of crews today; language is a key determinant of this phenomenon. The implication behind this trend is that the profession of ‘seaman’ in the OECD countries is becoming less attractive from the point of view of personal and even professional life. The human decapitalization of maritime personnel is also a strategic problem in the provision of specialized seamen for tasks of the Maritime Administration and PSC Inspection, together with the progressive aging of the existing crews.     

Evaluation and Customization of Different Open Source Desktop GIS Software

This paper gave a general evaluation on existing three popular free and open source desktop GIS projects,according to the selected evaluation criteria.To further the understanding of the open source software,this paper also presented a customization example of QGIS with python and PyQT.     

GIS互操作与OGC规范

不同GIS间的互操作是地理信息共享与服务的一个至关重要的问题,制订地理信息的互操作标准、规范已成为解决问题的关键。本文描述了在分布式计算环境下GIS互操作的含义、面临的问题与标准化需求;简述了开放地理信息系统协会(OGC)的地理信息互操作视点、互操作应用程序接口;着重介绍了互操作规范及其相互关系,已获采纳的实现规范及其制定流程、已进入讨论稿和推荐稿阶段的实现规范。     

A LINEAR THEORY FOR DISTURBANCE OF COHERENT STRUCTURE AND MECHANISM OF SAND WAVES IN OPEN-CHANNEL FLOW

1 INTRODUCTIONT'he early theory for tUrbulent boundare layer assumed that the now adjacent to the wall is a lndnar innature and is named lndnar bottom layer Its thickness is about V/u*, Where V is the ldnehc viscosityand u* is the fuchon velocity. Towmsend (l956) first suggested the concePt of tUrbulent strUctUre andpointod out that there are isotroPic small scale nuctUation and quasi-periodic large scale strUcture in theshear flow Einstein and Li (l956) discovered by the flow moving…     

VELOCITY PROFILES OF TURBULENT OPEN CHANNEL FLOWS

1 INTRODUCTIONThe vertical velocity profile of open channel flows is the most basic infOrmation for the stUdy of flowresistance, channel bed stability, river nuvial process and sediment transport. Although it has been asubject of great interest for many years, there does not exist a consensus on some perPlexing questions,such as the position of the theoretical bed level. In order to investigate the properties of velocity profile,data measured in open channel nows from eight sources were …