2011年渭河和汉江上游秋汛期环流特征及暴雨致洪成因

2021年汉江秋汛期出现了超20 a一遇的大洪水,其上游累计降雨量和丹江口水库累积来水量均突破其历史极值。如何有针对性做好气象保障服务,对气象部门而言是重大挑战。基于对2021年汉江异常秋汛水雨情特征的总结及其气象保障服务过程的回顾,指出汉江秋汛气象保障服务工作中存在的若干问题,提出不断提高汉江秋汛气象保障服务质量和效率的若干风险管理机制,可为今后做好汉江秋汛气象保障服务提供参考依据。

     

空间信息技术是防洪减灾现代化的基础

我国洪涝灾害频繁,洪灾损失严重,防洪减灾将是一项长期而艰巨的任务。在防洪减灾研究中,必须积极引进当今最新科学技术成果,以高新技术改造水利这一传统产业,以水利信息化推动水利现代化。以遥感、地理信息系统和全球导航定位系统为支撑的空间信息技术可以广泛地应用于防洪减灾中,是防洪减灾现代化的基础。本文分析了空间信息技术在防洪减灾中的作用,并对空间信息技术在防洪减灾中的应用趋势作出展望。     

空间数据挖掘进展

空间数据挖掘是解决海量空间数据利用瓶颈的技术之一。本文综述空间数据挖掘的研究与应用进展。首先,分析空间数据挖掘的缘起。其次,研究空间数据挖掘的本质及其特点。再次,基于理论技术,分类总结空间数据挖掘的研究和应用的成果,并探讨其研究方向。最后,总结全文。     

Modelling road surface sediment production using a vector geographic information system

Field investigations indicate that unpaved roads are the largest sediment source on St John, US Virgin Islands. Cross-sectional measurements of eroded road surfaces were used to establish an empirical relationship to predict annual road surface erosion as a function of road gradient and contributing drainage area. A model (ROADMOD) for estimating and mapping average annual sediment production from a road network was developed by combining this empirical relationship with a series of network algorithms to analyse road data stored in a vector geographic information system. ROADMOD was used to estimate road surface erosion in two St John catchments with very different road densities but similar land cover, topography and soils. Unpaved roads were found to increase sediment production in the more densely roaded catchment by a factor of three to eight, and in the less-roaded catchment by a factor of 1·3–2·0. Turbidity measurements in the receiving bays of these two catchments are consistent with model predictions and observed sediment delivery processes. Although this model was developed specifically for St John, it can easily be adapted to other locations by substituting a locally derived predictive equation for road erosion. Model assumptions, limitations and potential improvements are discussed. © 1998 John Wiley & Sons, Ltd.     

广州市汽车服务业布局实证研究

以广州市为研究区域,在总结汽车服务业发展历程的基础上,通过实证分析,认为经过20多年的发展,目前广州市汽车服务业的空间布局特征明显,在全市不同地域空间分布不均衡,在各个区的分布也存在明显数量差异;集聚趋势显著,大部分沿城市干道分布。影响广州市汽车服务业布局的因素主要有土地成本、市场、历史、关联产业、集聚效益、政府决策6个方面。     

基于遥感影像的地理特征信息的提取与分析

以云南省会泽县为例,基于ETM+、ASTER、DEM等遥感影像数据运用ArcGIS、ERDAS等遥感软件提取研究区的植被、地形、坡度坡向等一系列地理特征信息,并生成相关图件,为本区的农业规划、水土流失、地质灾害、资源开发、土壤侵蚀等相关研究提供多方面的空间信息参考.     

The GeoCitizen-approach: community-based spatial planning – an Ecuadorian case study

Over the last years, geospatial web platforms, social media, and volunteered geographic information (VGI) have opened a window of opportunity for traditional Public Participatory GIS (PPGIS) to usher in a new era. Taking advantage of these technological achievements, this paper presents a new approach for a citizen-orientated framework of spatial planning that aims at integrating participatory community work into existing decision-making structures. One major cornerstone of the presented approach is the application of a social geoweb platform (the GeoCitizen platform) that combines geo-web technologies and social media in one single tool allowing citizens to collaboratively report observations, discuss ideas, solve, and monitor problems in their living environment at a local level. This paper gives an account of an ongoing participatory land-zoning process in the Capital District of Quito, Ecuador, where the GeoCitizen platform is applied in a long-term study.     

Using Web Maps to Analyze the Construction of Global Scale Cognitive Maps

Game-based Web sites and applications are changing the ways in which students learn the world map. In this study, a Web map-based digital learning tool was used as a study aid for a university-level geography course in order to examine the way in which global scale cognitive maps are constructed. A network analysis revealed that clicks were negatively correlated with familiarity, but were positively correlated with area. More significantly, well-known countries did not act as central nodes within network-based mental models, but served a more complex mediating role in structuring the space between subregions.     

Aesthetic evaluation of yardang landforms landscape: the Dunhuang Yardang National Geo-park example

Dunhuang Yardang National Geo-park,situated in the Gansu Province of northwestern China(40o25'36 "N–40o33'10" N,93o00'00 "E–93o13'30" E),was chosen as a research locality of aesthetics evaluation of yardang landforms landscape.The yardang landforms landscape is a composite structural system of patch-corridor-matrix,with four landscape unit elements as dense group,sparse group,single body and remnant.The study of the landscape aesthetics spatial pattern of Dunhuang Yardang National Geo-park shows that yardang dense group,sparse group and single body provide the greatest contribution to the aesthetic value of yardang landforms landscape.Yardang bodies are scarce,unique,irreplaceable,and priceless resources in yardang landforms areas.However,they are easily destroyed under the influence of the natural and artificial factors.Therefore,when the tourism potential of yardang landforms landscape is exploited,the protection should be fully improved.     

Overcoming Trade Impediments: Considering SME Exporters from Nova Scotia

Firms often encounter location-based impediments that hinder them from engaging with international markets. These challenges can be exacerbated for smaller firms, which often have limited resources and exposure to global markets. This article examines successful small and medium-sized exporters from Nova Scotia, a province with decreased export activity in recent years. It explores these firms’ trade-related motivations, their impediments, and the strategies that they have used to address possible location-related problems. Although geographical distance does not appear to be a competitive challenge, other issues emerge, including travel expenditures and the costs of export intelligence gathering. Successful exporters have overcome many potential impediments by using government trade programs, establishing and maintaining face-to-face contacts, and working with international partners.