Understanding and modeling basin hydrology: interpreting the hydrogeological signature

Basin landscapes possess an identifiable spatial structure, fashioned by climate, geology and land use, that affects their hydrologic response. This structure defines a basin's hydrogeological signature and corresponding patterns of runoff and stream chemistry. Interpreting this signature expresses a fundamental understanding of basin hydrology in terms of the dominant hydrologic components: surface, interflow and groundwater runoff. Using spatial analysis techniques, spatially distributed watershed characteristics and measurements of rainfall and runoff, we present an approach for modelling basin hydrology that integrates hydrogeological interpretation and hydrologic response unit concepts, applicable to both new and existing rainfall‐runoff models. The benefits of our modelling approach are a clearly defined distribution of dominant runoff form and behaviour, which is useful for interpreting functions of runoff in the recruitment and transport of sediment and other contaminants, and limited over‐parameterization. Our methods are illustrated in a case study focused on four watersheds (24 to 50 km²) draining the southern coast of California for the period October 1988 though to September 2002. Based on our hydrogeological interpretation, we present a new rainfall‐runoff model developed to simulate both surface and subsurface runoff, where surface runoff is from either urban or rural surfaces and subsurface runoff is either interflow from steep shallow soils or groundwater from bedrock and coarse‐textured fan deposits. Our assertions and model results are supported using streamflow data from seven US Geological Survey stream gauges and measured stream silica concentrations from two Santa Barbara Channel–Long Term Ecological Research Project sampling sites. Copyright © 2004 John Wiley & Sons, Ltd.     

信息产业发展对宁波城市内部结构的影响

该文从信息产业的概念和分类人手，着重分析信息产业发展对城市产业结构、社会结构和空间结构的影响。对宁波市信息产业与城市产业结构的内在关系进行了量化研究；探讨信息产业对城市内部社会结构分异的变化趋势；提出了信息产业对城市内部空间结构功能置换的两种模式和地域扩张的促动机制。     

知识经济条件下的高校图书馆文献信息服务

知识经济时代文献信息资源是知识创新的源泉，信息服务业成为知识经济的先导产业。以高校高科技产业为例，说明了高校图书馆要立足于知识经济社会，只有拓宽文献信息服务的内容，同时为教学、科研服务，发展高科技产业。并对知识经济时代的高校图书馆文献信息服务提出了一些建议。     

ADAPT数字遥测地震台网中传递函数的辨识

Adapt系统可以利用脉冲标定波形得到系统的传递函数,它将复杂的传递函数计算过程简化了,用户可以将传递函数的测定作为一种日常工作来做。     

航空重力数据谐波小波滤波中卷积运算的处理

数据的滤波提取是航空重力测量数据处理的一个重要环节。谐波小波滤波器在频域具有良好的盒形谱特征,可以较好地实现信号的滤波。但谐波小波滤波器是一个连续函数,航空重力测量采集的信号是离散的,无法直接进行卷积运算。讨论了谐波小波用于航空重力数据滤波处理时的卷积运算处理方法,给出了谐波小波频域卷积的算法实现过程和仿真算例。     

Semantic segmentation of high spatial resolution images with deep neural networks

Availability of reliable delineation of urban lands is fundamental to applications such as infrastructure management and urban planning. An accurate semantic segmentation approach can assign each pixel of remotely sensed imagery a reliable ground object class. In this paper, we propose an end-to-end deep learning architecture to perform the pixel-level understanding of high spatial resolution remote sensing images. Both local and global contextual information are considered. The local contexts are learned by the deep residual net, and the multi-scale global contexts are extracted by a pyramid pooling module. These contextual features are concatenated to predict labels for each pixel. In addition, multiple additional losses are proposed to enhance our deep learning network to optimize multi-level features from different resolution images simultaneously. Two public datasets, including Vaihingen and Potsdam datasets, are used to assess the performance of the proposed deep neural network. Comparison with the results from the published state-of-the-art algorithms demonstrates the effectiveness of our approach.     

水资源约束下西北干旱区河西走廊城市化发展模式

西北干旱区城市化进程受到水资源短缺及其用水结构不合理的双重约束。本文以甘肃河西走廊为例 ,针对河西走廊未来 30年总需水量阈值、经济总量阈值、总人口阈值和城市化水平阈值 ,认为最经济、最节水的城市化发展方针为禁止发展特大城市 ,有选择地培育一个大城市 ,积极发展中小城市 ,科学发展小城镇。据此提出了与水资源约束相适应的西北干旱区河西走廊城市化发展的 6种模式。即 :推行“产业移人”和“环境移民”为主、“人移产业”为辅的城市扩展模式 ;推行“分步到位”为主 ,“一步到位”为辅的城市生态移民模式 ;推行“退一进二”、“退乡进城”的城市用水转换模式 ;推行“节水量城”为主 ,“借水养市”为辅的节水型城市化模式 ;推行“稳粮兴草” ,“稳农强工” ,“活商旺城”的城市产业转换模式 ;推行“一核四极” ,“一轴三带”、“乡镇同兴”的“卅”字型城市空间推进模式     

防汛信息共享与元数据应用研究

分析了FGDC、CEN／TC287等元数据标准，讨论了基于GIS的防汛信息共享与元数据的应用，设计了防汛信息元数据库，实现了元数据支持下的防汛信息共享。     

城市地理信息系统建设中的若干问题及解决思路探讨

分析了城市地理信息系统(UGIS)建设与发展中存在的标准化、信息安全、运营机制等问题,并给出了相应的解决思路;阐述了相关行业部门协作与产业化发展的方向。     

中小城市基础地理信息建设中的问题与建议

空间基础地理信息是城市信息基础设施建设的重要组成部分,中小城市地理信息系统建设的核心是空间基础数据。本文对我国中小城市空间基础地理信息建设现状和存在的问题进行了分析,认为目前中小城市的规划和勘测部门在空间基础地理建设中主要存在数据形式多样、标准不统一和更新不力等问题,对此提出了一些关于数据库建设和数据更新的建议。