Hydrological and hydrodynamic modeling for flood damage mitigation in Brahmani–Baitarani River Basin,India

Stream flow forecast and its inundation simulations prior to the event are an effective and non-structural method of flood damage mitigation. In this paper, a continuous simulation hydrological and hydrodynamic model was developed for stream flow forecast and for spatial inundation simulation in Brahmani–Baitarani river basin, India. The hydrologic modelling approach includes rainfall-run-off modelling, flow routing, calibration and validation of the model with the field discharge data. CARTOSAT Digital Elevation Model of 30 m resolution, land use/land cover derived from the Indian Remote Sensing Satellite (IRS-P6) AWiFS and soil textural data of the study area were used in the modelling to compute topographic and hydraulic parameters. The hydrological model was calibrated with the help of field observed discharge data of 2006 and 2009 and validated with the data of 2008 and 2011. From the results, it is found that computed discharges are very well matching well with the observed discharges. The developed model can provide the stream flow forecast with more than 30 h lead time. Possible flood inundations were simulated using hydrodynamic modelling approach. CARTO Digital Elevation Model of 10 m resolution, landuse and the computed flood hydrographs were used in inundation simulations.     

基于代理技术的多源GIS服务访问控制方法设计与实现

GIS门户用于整合各种来源的GIS服务,并为用户提供统一的GIS服务访问入口.访问控制是GIS门户建设的重要技术基础,现有方法是通过授权机制,授予用户相应GIS服务的访问权限.由于不隐藏原始服务地址,即使用户被取消授权,但因其已获取过原始服务地址,依然可绕过GIS门户访问相应的GIS服务,GIS门户无法对已注册GIS服务的访问情况进行控制.通过代理技术可以有效地隐藏原始服务地址,但由于GIS门户的特殊性,使用现有的代理服务器不仅配置复杂,而且要与GIS门户的授权机制相结合,实现难度大.为解决以上问题,本文基于代理技术的思路,自主研发实现了一种多源GIS服务访问控制方法,采用对注册GIS服务的原始服务地址的隐藏机制,以及建立与之对应的代理服务地址的映射关系,使得被授权用户只能访问代理服务地址,进而实现GIS门户中对注册GIS服务的访问控制.基于此设计实现的SuperMap iPortal注册服务访问控制模块,支持对注册的多源GIS服务进行代理,提供统一的代理服务根地址,方便对多源GIS服务进行统一使用、管理和维护.     

大连市沿海丘陵地区地铁精密控制网关键技术研究

介绍了大连市沿海丘陵地区地铁施工控制网布设、观测中关键技术的研究及解决方案,其中利用GPS静态观测与传统精密导线测量相结合组成混合网平差、将精密导线点纳入二等水准网,实现平高复用等技术,可给同类工程实施提供参考。     

基于Android的控制点手持维护系统的设计与实现

针对传统的控制点管理方法无法解决信息量匮乏、信息现势性不足、不便于野外操作等问题,提出了一种新的基于Android的控制点手持管理方法。采用控制点信息建模技术和移动数据库接口技术,实现了对控制点信息的实时更新;采用网络地图服务集成技术,实现了对控制点信息的深度挖掘以及便于野外操作。通过基于Android的控制点手持维护系统的开发表明:结合Android终端与网络地图服务,可以避免传统方法的不足,更加有效的进行控制点的管理与维护。     

航空遥感稳定平台的模型参考自适应控制

针对航空遥感惯性稳定平台中所受到的不平衡力矩等所引起的成像载荷不稳定导致无法获取高分辨率遥感数据的问题,提出了在平台控制系统中应用基于模型参考的自适应比例-积分-微分控制方法。根据需求设计出参考模型,将参考系统输出与实际系统输出之间的误差输入到自适应PID调节器,实时调整PID参数,对误差进行实时校正,以达到抑制不平衡力矩扰动、提高稳定平台稳定精度的目的。对所提出的模型参考自适应控制方法进行了仿真验证,结果表明:相对传统PID方法,模型参考自适应控制器对偏心力矩等主要干扰具有很好的抑制作用,系统输出能够很好地跟踪姿态变化,系统稳定精度得到显著提高。     

谈大数据时代的“云控制”摄影测量

在当今大数据时代,影像数据采集方式的多样化、高效化、便捷化产生的摄影测量影像大数据需要高效、自动与智能的处理。然而,作为传统摄影测量几何定位主要控制数据的外业控制点,其获取的复杂性与低效性仍然是制约摄影测量处理效率的关键因素。针对该问题,本文提出了"云控制"摄影测量的概念,以带有地理空间信息的数据作为几何控制替代外业控制点,通过自动匹配(或配准)获取大量密集的控制信息;并介绍了基于影像、矢量和LiDAR点云的3种"云控制"摄影测量技术;最后对"云控制"摄影测量的应用前景进行了展望并对其问题进行了讨论。     

基于天绘卫星影像的困难地区地形图测制方法

介绍了基于天绘影像的困难地区地形图测制技术,针对困难地区地形图的特点,分析影响地形图测制的因素,总结了提高困难地区地形图成果质量的方法。     

基于华浩超算平台遥感影像几何校正研究——以资源一号02C数据为例

对多源遥感影像进行几何校正是遥感影像应用的重要环节,以往的遥感影像利用人工或半自动的方式进行几何校正时,存在校正结果难以预料,控制点精度不可控,二次校正过程中控制点利用效率较低等问题。本文基于以上问题,利用华浩超算平台,对资源一号02C卫星10 m多光谱影像和2.36 m全色影像进行几何校正。试验证明华浩超算平台的实时几何校正模块,可以对每一个精校正后控制点的精度进行实时控制,并有效地解决了控制点利用效率低的问题。     

不同型号GNSS在同一控制网中的兼容性分析

随着GNSS广泛应用于地籍测量和工程测量、大坝和大型建筑物变形检测以及地壳运动观测等领域。在布设控制网和施工过程中,往往存在同一型号仪器数量不足的问题。为解决这一问题,本文在同一控制网中使用不同型号的仪器同时作业,将不同接收机数据格式进行统一,并处理各种卫星信号,并进行联合基线解算、平差。研究结果表明:不同型号接收机在同一控制网中联合应用精度高于同一型号接收机在同一控制网中联合应用精度。     

INTEGRATED RISK ASSESSMENT OF MAJOR METEOROLOGICAL DISASTERS WITH PAPRIKA PEPPER IN HAINAN PROVINCE

Paprika pepper, as one of the main vegetable crops, is originated in the tropics and now widely planted in the world for its dietary therapy and medicinal functions. For its typical physiological properties referring to low tolerances to flood, drought and cold, paprika pepper often suffers from one or several disasters during its growing period, especially under tropical climate. Paprika pepper in Hainan, as a typical region of tropical climate in China, sustains flood, chilling and drought disaster risks induced by varied weather systems. This study was to develop and employ appropriate indices to assess hazard, sensitivity, vulnerability and prevention capability for major disasters during paprika pepper growth period, using long-term meteorological data from 1998 to 2011, actual disasters record from 1999 to 2011, production and socioeconomic statistics from 2002 to 2011 at 18 weather stations. Based on the Analytic Hierarchy Process and Entropy method, the combined weight was given to each disaster factor, thus an integrated disaster risk assessment model was developed and applied at regional level. High flood hazard mainly occurred in eastern Hainan, high chilling hazard in north and central mountain areas, and high drought hazard in the western part of Hainan. Drought and chilling sensitivity had a similar spatial distribution which decreased from central to coastal regions while flood sensitivity was the opposite. High vulnerability of the disasters mainly occurred in central regions, similar to low prevention capability. Eastern Hainan suffered from high integrated damage risk. The predicted damage occurrence showed a good agreement with the occurrence of actual disasters. We concluded that an integrated damage risk assessment model could provide a new tool to assess major meteorological disasters and help farmers and policy makers to alleviate the risks of major meteorological disasters for paprika pepper, which seems also suitable for other crops.