流域型灾害特征信息提取及动态预警算法

针对目前流域型灾害特征信息提取和动态预警方法不能满足实践需要的现实问题,为了提升流域型灾害特征信息提取和灾害动态预警技术水平,以典型流域型灾害为研究对象,剖析了流域型灾害性能参数计算及动态预警实现的核心环节,提出了基于无线传感网络(WSN)的流域型灾害特征信息计算方法,设计了流域型灾害动态预警信息处理算法.以典型流域型灾害的性能参数采样值为数据,运用Matlab仿真平台对其核心性能参数进行了仿真分析.实验结果表明,所提算法能够有效捕捉流域型灾害的核心动态特征信息,提高了流域型灾害动态预警指示的准确度.     

交互式流域算法在医学图像分割中的应用

本文首先介绍了流域算法的基本思想、基本原理以及流域变换过程中所存在的问题,回顾了为加快流域变换的计算而进行的大量研究工作,然后利用区域信息、结合交互式流域变换分割医学图像,实验结果表明该方法能有效地解决流域变换中的过度分割问题。     

基于物联网理念的流域智能调度技术体系刍议

针对流域调度面临着监测信息不全面、传输效率低下、计算速度远远不能满足实际要求等问题,物联网技术的出现改变了这一局面,为流域调度发生突破性进展奠定了坚实基础。以此作为出发点,总结分析了流域调度的特点和要求,以及现有调度系统存在的问题,并探讨了物联网技术与流域调度的联系。以保障防洪、供水、生态、能源、航运和工程等安全为目标,提出了基于物联网技术的流域智能调度技术体系,对流域智能调度中的智能感知、仿真、诊断、预警、调度、处置、控制、综合指挥平台、数据处理和运维等关键技术进行了研究。最后在物联网技术的基础上,结合流域信息化的发展趋势和数字流域的建设,提出了"智慧流域"的概念。     

都江堰市白沙河子流域划分与水系提取研究

文章以四川省都江堰市白沙河流域为研究对象,采用10×10m分辨率的DEM为基本地形数据,应用ArcGIS水文分析模块对该流域进行水系提取与子流域划分工作。率定不同的集水栅格阈值,分别将提取得到的水系与实际水系进行对比,结果表明集水栅格阈值为5000时提取的水系与实际河网最接近,说明0．5km。是该地区形成河网的集水面积阈值。在进行子流域划分汇水阈值取值时,如果仍采用与生成河网相当的阈值,则生成的子流域过多不利于做更深的水文分析。当集水栅格阈值取50000,即子流域面积为5km。时生成的子流域较为合理,以此将研究流域划分为37个子流域,为进一步的水文分析提供了流域基础数据。     

基于 Micaps3.1的暴雨洪涝预报预警模块的研发

文中利用 C#. NET 构建了基于 MICAPS3.1系统应用的暴雨洪涝预报预警系统整体框架,重点介绍了该系统开发的基本情况、系统架构和系统中使用的关键技术和算法.并选取汉江丹江口为试验流域,初步完成了流域基础地理(边界、水系)、气象、水文监测站点的收集以及显示;流域 QPE、QPF、实况监测等气象要素实时产品信息的提取以及气象要素产品与水文模型接口的设计;最后提供了流域实况降水监测场、流域实况降水雷达估算场、流域预报雨量场、流域水文预报信息数据、图形等产品文件.该模块的研发能为流域防洪决策提供支持,并为河流防汛精细化预报服务试点工作的推广提供经验和模式     

可视化仿真关键技术及其在数字流域可视化中的应用

数字流域是数字地球的一个重要区域层次,数字清江是数字流域建设在清江流域的具体实践。本文讨论了多层次细节技术、虚拟纹理技术和大规模数据库管理技术等可视化仿真关键技术及其在隔河岩坝区漫游系统中的实际应用,为搭建数字流域的可视化基础信息平台提供了技术依据和实践经验,对创建面向数字流域的可视化仿真系统进行了有益的探索。     

基于Micaps3.1的暴雨洪涝预报预警模块的研发

文中利用C#.NET构建了基于MICAPS3.1系统应用的暴雨洪涝预报预警系统整体框架,重点介绍了该系统开发的基本情况、系统架构和系统中使用的关键技术和算法。并选取汉江丹江口为试验流域,初步完成了流域基础地理（边界、水系）、气象、水文监测站点的收集以及显示;流域QPE、QPF、实况监测等气象要素实时产品信息的提取以及气象要素产品与水文模型接口的设计;最后提供了流域实况降水监测场、流域实况降水雷达估算场、流域预报雨量场、流域水文预报信息数据、图形等产品文件。该模块的研发能为流域防洪决策提供支持,并为河流防汛精细化预报服务试点工作的推广提供经验和模式。     

应用卫星遥感技术评价流域森林水文效益

本文论述应用卫星遥感技术结合地面人工降雨试验和流域多年水文资料的方法,对流域森林水文效益进行评价。通过研究,弄清了流域下垫面要素的性质和结构,以及流域森林水文效益动态变化规律,提出了研究森林水文效益的实用区划方法,即“土壤景观——森林水文区域研究”,以及流域森林水文效益的数量化评价技术,并对该流域的蓄水能力进行预估,为“八·五”长防林建设研究奠定了基础。     

基于DEM的三维景观在流域模拟中的应用

流域模拟试验区的选取受到诸如地理过程复杂性和数据获取难度大等因素的制约,传统的实地踏勘方法不能满足大尺度流域试验区的选取要求。该文提出基于数字高程模型和遥感影像建立三维景观图的方法,构建了流域三维地表模型,从不同视角、尺度观察整个流域及子流域划分情况,为确定试验区提供了客观、科学的依据。     

GEF海河流域水资源与水环境综合管理知识管理系统

GEF海河流域水资源与水环境综合管理知识管理系统是GEF海河项目的核心内容之一,是海河流域水资源和水环境管理信息的存储、管理和共享交换中心;利用先进的3S(GIS/RS/GPS)和IT技术,建设流域水资源与水环境知识共享平台,实现海河流域水利与环保部门之间的信息交流与共享;以遥感监测ET为管理措施、水功能区为管理单元、水权为管理核心、模型为支撑工具、取水许可与排污许可为控制手段,构建海河流域水资源与水环境综合业务管理系统;该系统的建设为加强海河流域水资源与水环境综合管理,促进各级水行政管理部门间的协调合作,改善海河流域水资源与水环境状况提供了重要的技术手段和成功经验。     

Cover: IRS-1C-PAN depicts Chamoli earthquake induced landslides in Garhwal Himalayas,India

Alluvial geomorphic surfaces in the southern Whipple Mountains (south-eastern California) were mapped using Landsat Thematic Mapper (TM) data. Surfaces can readily be classified as young, intermediate or old in terms of stages of development. Spectral and textural information contained in these data are interpretable in terms of source rock composition, degree of desert pavement formation and drainage patterns, which are among the most important criteria used in field-based classification. Thus, classification and mapping of geomorphic surfaces based on image analysis is directly comparable to maps produced from field-based observations, potentially providing information about climate and neotectonics.     

Extraction of bajadas from digital elevation models and satellite imagery

A methodology was designed for the extraction of bajadas from the 15 min US Geological Survey digital elevation models and Landsat Thematic Mapper imagery. The method was demonstrated for the Death Valley-California where progressive eastward tilting has enabled the west-side fans to coalesce and form bajadas. First, the drainage that crossed the uplands and the bajadas was extracted from the DEM. The drainage pixels were successively grown by checking the surrounding pixels on the basis of their gradient. It was concluded that for gradient in the interval [2°,11°] the upslope bajadas border was segmented. In order to eliminate the drainage pixels that belonged to the uplands, the drainage pixels were subtracted. Then, the isolated small 8-connected foreground pixels were identified and subtracted too. Finally, region growing was performed again to the remaining pixels with the same growing criterion. Isolated 8-connected background pixels, representing almost flat regions inside bajadas, were identified and merged to the segmented pixels. At the end, by taking into account the spectral response in the satellite image, the downslope border of bajadas was segmented. The extracted polygon was in agreement with the information depicted on (a) the US Geological Survey topographic map of scale 1:100,000 and (b) the satellite image and (c) the polygon classified manually by a photo-interpreter.     

Digital terrain analysis using Landsat‐7 ETM+ imagery and SRTM DEM: a case study of Nevsehir province (Cappadocia), Turkey

A three‐dimensional (3D) model of land‐use/land‐cover (LULC) and a digital terrain model of Nevsehir province (Cappadocia), Turkey, were generated and analysed using a Landsat‐7 Enhanced Thematic Mapper Plus (ETM+) multispectral image set and a Shuttle Radar Topographic Mission (SRTM) digital elevation model (DEM). Stream drainage patterns, lineaments and structural‐geological features (landforms) were extracted and analysed. In the process of analysing and interpreting the multispectral images of geological features, criteria such as colour and colour tones, topography and stream drainage patterns were used to acquire information about the geological structures of the land, including as geomorphological, topographic and tectonic structures. Landsat‐7 ETM+ multispectral imagery and an SRTM DEM of the study region were used experimentally for classification and analysis of a digital terrain model. Using the multispectral image data, the LULC types were classified as: settlement (1.2%); agricultural land (70.1%); forest (scrubland, orchard and grassland) (2.9%); bare ground (25.5%); and water bodies (lakes and rivers) (0.3%) of the study area (5434 km²). The results of the DEM classification in the study area were: river flood plain (11.3%); plateau (52.3%); high plateau (28.4%); mountain (7.6%); and high mountain (0.3%). Lineament analysis revealed that the central Kizilirmak River divides the region into two nearly equal parts: the Kirsehir Plateau in the north and the Nevsehir Plateau in the south. In terms of the danger of catastrophe, the settlements of Kozakli, Hacibektas and Acigol were found to be at less risk of earthquake and/or flooding than those of Avanos, Gulsehir, Urgup, Nevsehir, Gumuskent and Derinkuyu, which are located on river flood plains and/or the main stream drainage channels, particularly stream beds, where the lineaments are deep valleys or fracture or fault‐line indicators.     

Film drainage mechanism between two immiscible droplets

The interaction between two deformable droplets consists of unique dynamic characteristics that are not present during the interaction of solid bodies. A thin film of surrounding fluid is entrapped between the droplets and then drains out under the influence of an external force before the droplets can adhere or coalesce. The drainage process during the coalescence of two similar droplets has received significant research interest due to the presence of dynamical interactions between the droplets. Surprisingly, the film drainage process between two partial engulfing immiscible droplets has not been studied yet. Using a numerical study, we investigate the film drainage between two partial engulfing immiscible droplets. We vary the interfacial tensions between the droplets and surrounding fluid in wide ranges to observe the film drainage time between the droplets. Based on our simulations, we identified three regimes of fast, intermediate and delayed drainage. We found that the film drainage of two immiscible droplets exhibits additional flow into or out of the film, which does not exist in the film drainage of identical droplets. This additional flow can either increase or decrease the rate of film drainage between the droplets, depending on the interfacial tension of droplets with the surrounding fluid and the interfacial tension of the two immiscible droplets.     

Radar topography data reveal drainage relics in the eastern Sahara

The Shuttle Radar Topographic Mission (SRTM) elevation data reveal segments of inactive drainage channel systems in the eastern Sahara. Four sites are investigated and their drainage networks are delineated and compared with processed Synthetic Aperture Radar (SAR) and Enhanced Thematic Mapper Plus (ETM+) images. These include parts of the drainage lines that lead to the Kufra Oasis in Libya; the eastern Gilf Kebir drainage system that straddles the border region between Egypt and Sudan; the lower reach of Wadi Howar, the extinct western Nile tributary in Sudan; and a reversed flow channel of Wadi Kubbaniya northwest of Aswan in Egypt. These features are delineated using SRTM data and a Geographic Information System (GIS) hydrologic routine. The results show that the SRTM signals penetrate the desert‐sandy surfaces and map ancient drainage systems in the same way as SAR. The study also demonstrates that SRTM data can be used to confirm or modify pathways of channel courses mapped from radar images alone. Because of this capability, it is also recommended that SRTM data be used in place of GTOPO30 elevation data in hydrologic modelling of sand‐covered deserts.     

采空区瓦斯抽采钻孔参数及注氮防灭火研究

钻孔抽采能够影响采空区内部风流的运动,从而导致采空区流场发生变化,增加工作面向采空区的漏风,同时钻孔周围呈现负压状态,漏风风流也不断向钻孔周围补充,采空区煤体在漏风集中区域呈现氧化升温状态,存在采空区遗煤自燃问题。针对上述问题,研究了钻孔抽采条件下采空区最优注氮防灭火方案。以白龙山煤矿10201工作面为背景,用数值模拟软件对工作面采空区进行仿真,分析了不同抽采参数下的采空区流场和温度场分布,依据合理钻孔参数确定了最优注氮条件。结果表明:抽采负压为30kPa时瓦斯抽采效果良好,氧化升温带增幅相对较低;钻孔间距为6m时抽采效果佳且工程量较小;进风侧注氮口与工作面距离为75m、注氮流量为1 500m^3/h时,可以很好地缩小氧化升温带宽度并节约成本。实际应用结果表明:综放工作面及上隅角瓦斯体积分数得到了有效控制,均低于1%;抽采管路及上隅角CO体积分数分别低于0.040%,0.032%,采空区煤体未发生自燃,采空区瓦斯抽采和注氮取得了良好的应用效果。     

Automatic generation of hypsometric layers for small-scale maps

This paper describes a new method for hypsometric tinting for small-scale maps. The method generalises digital elevation models by removing small unnecessary details and accentuating major valleys and ridgelines. The elevation data are filtered with lower and upper quartile filters that are combined using a drainage network. The lower quartile filter is applied in valleys, delimited by the drainage network, the upper quartile filter is used elsewhere. The level of generalisation is adjusted by simplifying the drainage network with an algorithm that removes the shortest streams. The resulting hypsometric layers match the quality standards of manually generalised reference layers and are appropriate for small-scale mapping.     

排污业务信息系统的设计与实现

绍兴县给排水公司的一项核心业务是各乡镇企业排污资料的汇总和结算.由于排污费用越来越成为乡镇企业的一项重要支出,公司需要建立一个高效的信息系统进行数据收集和处理.要建立这样一个系统,必须对公司目前的业务流程进行必要调整,形成一个高效的污水数据收集、汇总、统计、查询、打印的应用平台.     

杂散电流一体化智能综合监控分析系统的研究

针对杂散电流的泄露对设备及主体结构腐蚀和危害较大,常规检测技术功能单一的问题,提出了融合导通柜、排流柜、钢轨电位限位装置的一体化综合监控分析系统。通过分析钢轨电位与杂散电流的关系,并对导通柜、排流柜、及钢轨电位限制装置作智能化设计,能够进行智能化排流。系统包括参比电极、采集器、监测装置、排流柜、单向导通装置、主站后台等,根据全线杂散电流控制指标,结合不同设备状态及其与杂散电流系统的耦合情况,对多元参数进行分析运算,给出智能导通柜、排流柜、及钢轨电位限制装置一体化最优控制方式,以达到最优化的杂散电流治理效果。试验表明,本文设计的方案最大限度的减少了杂散电流的泄露对设备及主体结构的腐蚀和危害,延长设备及轨道洞体结构的使用寿命。     

煤矿井下排水泵控制系统设计

在煤矿井下的排水系统中,需要多台排水泵协调地工作。文章针对煤矿井下排水泵的特点,通过分析其控制要求,在系统控制的可靠性和控制实现的简洁性、经济性之间寻求最佳化,给出了实现多台排水泵电机均衡运行和自动轮值控制的一种方法。