Perceptual models of uncertainty for socio-hydrological systems: a flood risk change example     

Ida K. Westerberg  Keith J. Beven  Gemma Coxon  Tobias Krueger 《水文科学杂志》2020,65(Z2):1705-1713

ABSTRACT

Characterizing, understanding and better estimating uncertainties are key concerns for drawing robust conclusions when analyzing changing socio-hydrological systems. Here we suggest developing a perceptual model of uncertainty that is complementary to the perceptual model of the socio-hydrological system and we provide an example application to flood risk change analysis. Such a perceptual model aims to make all relevant uncertainty sources – and different perceptions thereof – explicit in a structured way. It is a first step to assessing uncertainty in system outcomes that can help to prioritize research efforts and to structure dialogue and communication about uncertainty in interdisciplinary work.  相似文献   

Catchment properties,function, and conceptual model representation: is there a correspondence?          下载免费PDF全文

Fabrizio Fenicia  Dmitri Kavetski  Hubert H. G. Savenije  Martyn P. Clark  Gerrit Schoups  Laurent Pfister  Jim Freer 《水文研究》2014,28(4):2451-2467

This study investigates the possible correspondence between catchment structure, as represented by perceptual hydrological models developed from fieldwork investigations, and mathematical model structures, selected on the basis of reproducing observed catchment hydrographs. Three Luxembourgish headwater catchments are considered, where previous fieldwork suggested distinct flow‐generating mechanisms and hydrological dynamics. A set of lumped conceptual model structures are hypothesized and implemented using the SUPERFLEX framework. Following parameter calibration, the model performance is examined in terms of predictive accuracy, quantification of uncertainty, and the ability to reproduce the flow–duration curve signature. Our key research question is whether differences in the performance of the conceptual model structures can be interpreted based on the dominant catchment processes suggested from fieldwork investigations. For example, we propose that the permeable bedrock and the presence of multiple aquifers in the Huewelerbach catchment may explain the superior performance of model structures with storage elements connected in parallel. Conversely, model structures with serial connections perform better in the Weierbach and Wollefsbach catchments, which are characterized by impermeable bedrock and dominated by lateral flow. The presence of threshold dynamics in the Weierbach and Wollefsbach catchments may favour nonlinear models, while the smoother dynamics of the larger Huewelerbach catchment were suitably reproduced by linear models. It is also shown how hydrologically distinct processes can be effectively described by the same mathematical model components. Major research questions are reviewed, including the correspondence between hydrological processes at different levels of scale and how best to synthesize the experimentalist's and modeller's perspectives. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

网络大数据下的中国现代食甜习惯空间分布特征及其影响因素研究     

姚可桢  岳书平 《地球信息科学学报》2020,22(6):1202-1215

饮食地理文化作为地域文化中最具地方特色的重要元素,在现代人口大规模流动背景下呈现出全新的多样化局面,而基于传统认知的“南甜北咸”的地域分异已然不能代表中国现代食甜分布的空间特征。因此,本文采用网络爬虫技术,获取我国大陆31个省会城市共计约2000万条美食消费数据,从传统类菜品、主食类菜品、饮料类和甜品类菜品4个方面计算城市食甜度,在ArcGIS、MySQL软件支持下,借助GIS空间分析和数理统计方法探究我国现代食甜习惯的空间分布特征,分析影响食甜分布的因素。研究发现：① 中国食甜在空间分布上存在显著的地域分异特征,聚类分析评价参数R ²高达0.88,现代食甜习惯总体呈现“东高北中,西微内低”的包围式格局;② 从整体抑或局部角度,在1%显著性水平上莫兰指数均为正,中国食甜分布呈现显著的空间正相关关系,形成特色鲜明的3个地理集聚区,即以苏浙沪闽为主的东南沿海高甜集聚区,以渝黔川为主的西南内陆低甜集聚区和以陕宁为主的西北内陆低甜集聚区;③ 构建了中国现代食甜习惯分布影响因素模型,其拟合精度为0.82,分析结果显示降水、湿度、气温等气象要素及地理位置是影响现代我国食甜空间分布的重要因素。  相似文献   

基于平均分组和叠加相关的GPS信号捕获方法     

杨久东  吴风华  王文军 《大地测量与地球动力学》2018,38(8):828-831

针对目前GPS软件接收机C/A码捕获信噪比门限高、捕获速度慢的问题，提出一种基于平均分组和叠加相关的GPS弱信号捕获方法。首先，基于平均相关处理技术降低C/A码捕获过程中的自相关损耗，提高对微弱信号的捕获能力；然后，利用叠加相关提高相干运算的运算效率，并采用线性插值提高自相关函数性能；最后，利用频偏校正和内插进一步提高C/A信号的捕获精度。理论分析和仿真实验均验证，该方法能够在较低的信噪比下实现GPS信号捕获，且精度较高、运算量较低。  相似文献   

运用ULBP的高分辨率遥感影像感知哈希完整性认证算法     

刘明轩  张黎明  王昊  马文骏  李玉 《测绘通报》2021,(12):22-27

针对现有高分辨率遥感影像感知哈希认证算法中特征提取精度和算法稳健性不能兼顾的问题,本文提出一种运用ULBP的高分辨率遥感影像感知哈希完整性的认证算法。首先对遥感影像进行格网划分,将影像划分为多个子块,运用ULBP算法提取子块的纹理特征;然后计算每个子块内纹理特征的直方图分布,将其结果与均值二值化后得到子块的感知哈希序列;最后串联所有子块的感知哈希序列生成整幅影像的感知哈希值。在影像认证时,首先计算原始影像与待检测影像的哈希序列,然后计算两者的感知哈希序列平均汉明距离,完成对高分辨率遥感影像内容的完整性认证与篡改定位。试验表明,该算法能够识别高分辨率遥感影像中地物较为平滑的区域,同时对JPEG压缩、高斯噪声添加、BMP格式转换等操作具有良好的稳健性,为高分辨遥感影像完整性认证提供支持。  相似文献   

Towards more systematic perceptual model development: a case study using 3 Luxembourgish catchments          下载免费PDF全文

Sebastian Wrede  Fabrizio Fenicia  Núria Martínez‐Carreras  Jérôme Juilleret  Christophe Hissler  Andreas Krein  Hubert H. G. Savenije  Stefan Uhlenbrook  Dmitri Kavetski  Laurent Pfister 《水文研究》2015,29(12):2731-2750

The synthesis of experimental understanding of catchment behaviour and its translation into qualitative perceptual models is an important objective of hydrological sciences. We explore this challenge by examining the cumulative understanding of the hydrology of three experimental catchments and how it evolves through the application of different investigation techniques. The case study considers the Huewelerbach, Weierbach and Wollefsbach headwater catchments of the Attert basin in Luxembourg. Subsurface investigations including bore holes and pits, analysis of soil samples and Electrical Resistivity Tomography measurements are presented and discussed. Streamflow and tracer data are used to gain further insights into the streamflow dynamics of the catchments, using end‐member mixing analysis and hydrograph separation based on dissolved silica and electrical conductivity. We show that the streamflow generating processes in all three catchments are controlled primarily by the subsolum and underlying bedrock. In the Huewelerbach, the permeable sandstone formation supports a stable groundwater component with little seasonality, which reaches the stream through a series of sources at the contact zone with the impermeable marls formation. In the Weierbach, the schist formation is relatively impermeable and supports a ‘fill and spill’‐type of flow mechanism; during wet conditions, it produces a delayed response dominated by pre‐event water. In the Wollefsbach, the impermeable marls formation is responsible for a saturation‐excess runoff generating process, producing a fast and highly seasonal response dominated by event water. The distinct streamflow generating processes of the three catchments are represented qualitatively using perceptual models. The perceptual models are in turn translated into quantitative conceptual models, which simulate the hydrological processes using networks of connected reservoirs and transfer functions. More generally, the paper illustrates the evolution of perceptual models based on experimental fieldwork data, the translation of perceptual models into conceptual models and the value of different types of data for processes understanding and model representation. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   

地震应急快速触发响应系统的参数配置与用户分组管理     

冯录刚  高景春  刘胜国  常亮  李永庆  王立军  丁瑞同  边鹏飞  王红蕾 《华北地震科学》2010,28(2):53-57

主要介绍了中国数字地震观测网络项目应急分项软件"地震应急快速触发响应系统"中的参数配置和用户分组管理2项重要的基础功能模块,详细阐述了这2项功能的具体实现方法和原理。  相似文献   

基于N-KD树的空间点数据分组算法     

魏海涛  杜云艳  任浩玮  刘张  易嘉伟  许开辉 《地球信息科学学报》2015,17(1):1-7

随着科学技术的进步,地理空间数据的分析处理面临着数据量膨胀和计算量高速增长的双重挑战,为了解决海量数据处理速度慢的问题,本文针对空间分布不均匀的点数据,从数据并行的角度,以保持数据的空间邻近性及保证数据分组后各组数据量负载均衡为目标,提出基于N-KD树（Number-K Dimension Tree）数据动态分组的方法,其是一种面向实时变化（数据量和数据空间范围变化）的空间数据动态分组方法。该方法借鉴K-D树的创建和最临近点搜索的思想,通过方差判断数据分布稀疏程度,利用最临近点搜索方法处理边界点,实现空间范围的不均等切分,保证数据分组后各组数据量基本均衡。试验表明,该方法具有较好的动态分组效果与较高的计算效率;支持各种分布状态的空间点数据的分组;分组后各组数据量负载均衡;分组算法本身有支持并行、支持分布式协同工作模式的特点。  相似文献   

一种面向遥感影像内容认证的多级权限管理方法     

丁凯孟  朱长青 《地球信息科学学报》2015,17(1):8-14

完整性认证是遥感影像获得有效利用的前提,完整性无法确定的遥感影像,其使用价值将大打折扣。传统认证技术没有顾及遥感影像认证过程中的特殊性,并不是所有用户都有权甄别遥感影像是否经过扰动。而且,传统认证技术对数据进行二进制级别的认证,已不能满足遥感影像的内容认证需求。本文从内容认证的角度研究遥感影像的多级权限管理,提出一种基于感知哈希技术与单向函数的遥感影像多级认证权限的管理方法。感知哈希技术能用很少的信息表征遥感影像的有效内容,并对不改变影像内容的操作保持鲁棒性,与密码学Hash函数有着显著的区别。多级权限的管理则通过建立与权限矢量对应的密钥矢量来实现,权限较高的用户可以通过自己的密钥计算出低权限用户的密钥,反之则不行。本方法首先以单向函数生成不同等级的权限密钥,然后,根据不同区域的地物影像进行敏感等级的划分,最后,计算不同区域影像的感知哈希序列,并通过不同级别的密钥加密生成的感知哈希序列。用户认证影像内容完整性时,根据权限的不同认证不同敏感度的影像。实验与分析表明,该算法能有效实现遥感影像的认证权限管理,并具有较高的实现效率和安全性。  相似文献   

Grouping response method for equivalent static wind loads based on a modified LRC method   总被引：1，自引：0，他引：1  

Xuanyi Zhou  Ming Gu  Gang Li 《地震工程与工程振动(英文版)》2012,11(1):107-119

Wind loading is one of the most important loads for controlling the design of large-span roof structures.Equivalent static wind loads,which can generally aim at determining a specific response,are wid...  相似文献