Monitoring directions and rates of change in trees outside forests through multitemporal analysis of map sequences

This study explores the potential of historical maps to detect, measure and monitor changes of trees outside forests. The main goal is to assess local-level changes of scattered trees and orchards and their land-use determinants in two areas in Southern Germany between 1901/1905 and 2009. Firstly, overall landscape changes are recorded. Secondly, the spatial-temporal trajectories of scattered trees and their land-use determinants are identified. Thirdly, changes in quantity and fragmentation patterns of traditional orchards are analyzed in their relationship to overall land-cover change. The results confirm major losses in scattered trees, mainly due to urbanization, agricultural intensification, and land abandonment. They further reveal that, while orchards have persisted in total area, they have undergone critical changes toward a simplified landscape structure and loss of the traditional land-use mosaic, which is a characterizing feature of high nature value landscapes. Multi-temporal assessment showed that most trends have been continuous and did not change directions over time, but rather accelerated during periods of rapid change (most dramatically in the 1950-1990 period). The case of orchards and scattered trees illustrates a major problem of cultural landscapes in Europe: Semi-natural landscape features of high nature value are threatened by both intensification and abandonment of land uses. This makes their conservation a potentially costly enterprise, as both opportunity costs for lost alternative land uses and for conservation management costs arise.     

An exploratory spatial analysis of western medical services in Republican Beijing

In this paper, we reconstructed the spatial organization of Western medical services in Beijing city during the Republican period using a recently completed Republican Beijing GIS dataset. The primary objective is to explore the utility of spatial analytical methods, such as hotspot analysis and geographically weighted regression (GWR), in studying the spatial patterns of Western medical services. Our study is successful in depicting the spatial structure of Western medical services in the city. In addition, our analysis offers a preliminary but holistic view of the spatial relationships between Western medical services in the city and traditional Chinese medicine, population distribution, temple locations and industry-commerce patterns.     

基于用户偏好的多维地理信息服务质量评价模型

为了解决目前地理信息服务质量量化评价的问题,构建了一种基于用户偏好的多维地理信息服务质量评价模型。扩展通用服务质量属性,构建了多维地理信息服务质量模型;在多维地理信息服务质量模型的基础上加入用户偏好,构建了基于用户偏好的多维地理信息服务质量评价模型;实现了基于用户偏好的QoS权重计算,并给出了服务QoS综合值的计算方法。最后给出了基于用户偏好的多维地理信息服务质量评价实例。     

Conceptualizing food systems for global environmental change research

This paper outlines a framework for studying the multiple interactions of broadly defined food systems with global environmental change and evaluating the major societal outcomes affected by these interactions: food security, ecosystem services and social welfare. In building the framework the paper explores and synthesizes disparate literature on food systems food security and global environmental change, bridging social science and natural science perspectives. This collected evidence justifies a representation of food systems, which can be used to identify key processes and determinants of food security in a given place or time, particularly the impacts of environmental change. It also enables analysis of the feedbacks from food system outcomes to drivers of environmental and social change, as well as tradeoffs among the food system outcomes themselves. In food systems these tradeoffs are often between different scales or levels of decision-making or management, so solutions to manage them must be context-specific. With sufficient empirical evidence, the framework could be used to build a database of typologies of food system interactions useful for different management or analytical purposes.     

Dealing with drought: The challenge of using water system technologies to break dryland poverty traps

We explore strategies among farmers in semi-arid Tanzania to cope with drought, and investigate if access to a local supplemental irrigation system (the Ndiva system) can improve coping capacity. Results show high dependency on local ecosystem services when harvests fail, and indicate that farmers commonly exhaust asset holdings during droughts. Ndiva access did not have any direct effects on coping capacity, but seemed to have some indirect effects. Drawing on our findings we discuss the complexity of escaping persistent dryland poverty, and outline the circumstances under which small-scale water system technologies, such as Ndiva irrigation, may help.     

Scale mismatches and their ecological and economic effects on landscapes: A spatially explicit model

Mismatches between the spatial scales of human decision-making and natural processes contribute to environmental problems such as global warming and biodiversity losses. People damage the environment through local activities like clearing land or burning fossil fuels, but the damages only become manifest at larger regional or global scales where no one pays for them. Payments for ecological services like carbon sequestration can correct for these damages caused by scale mismatches. This paper presents a spatially explicit land-use model to investigate the consequences of scale mismatches for pollination and carbon storage services and examine the effect of payment for only carbon storage services. The model integrates processes in multiple spatial scales ranging from the parcel level used by landowners’ decision about deforestation, to the larger scale used by animals to pollinate plants, and finally to the global scale where carbon storage services are supplied. We show that payment for carbon storage services can become an effective mechanism to protect forests at the same time that it creates inequities among landowners in income level.These findings suggest that market-based approaches that focus on conservation of a single ecosystem service may reproduce unequal power relations among landowners.     

地理本体及其应用初探

将本体论的思想和方法引入到地理信息领域,提出了本体论在地理信息科学中的确切含义,并阐述了建立地理本体的意义。重点研究了基于本体的地理信息服务,并在对各种本体表示语言进行分析比较之后,选择最有发展前景的OWL语言构建了一些简单的地理本体,用实例说明如何将本体应用到地理信息服务中。     

Pedestrian network generation based on crowdsourced tracking data

ABSTRACT

Pedestrian networks play an important role in various applications, such as pedestrian navigation services and mobility modeling. This paper presents a novel method to extract pedestrian networks from crowdsourced tracking data based on a two-layer framework. This framework includes a walking pattern classification layer and a pedestrian network generation layer. In the first layer, we propose a multi-scale fractal dimension (MFD) algorithm in order to recognize the two different types of walking patterns: walking with a clear destination (WCD) or walking without a clear destination (WOCD). In the second layer, we generate the pedestrian network by combining the pedestrian regions and pedestrian paths. The pedestrian regions are extracted based on a modified connected component analysis (CCA) algorithm from the WOCD traces. We generate the pedestrian paths using a kernel density estimation (KDE)-based point clustering algorithm from the WCD traces. The pedestrian network generation results using two actual crowdsourced datasets show that the proposed method has good performance in both geometrical correctness and topological correctness.     

关联视角下兰州市生产性服务业与制造业空间分布及区位选择比较

基于微观企业数据从关联性视角对兰州市生产性服务业与制造业空间分布特征和模式进行分析,进而探讨其区位选择因素的异同。研究表明：① 生产性服务业与制造业的空间布局均呈现出以主城区为主体、外围局部地区为补充的“中心-外围”空间格局,但生产性服务业集聚区主要集中在河谷地带的主城区,制造业集聚区则呈现出明显的郊区化趋势,二者在空间上存在关联的同时又具有一定的可分性。② 生产性服务业形成了以城市中心区和郊区国家级新区及卫星城镇为多元空间载体的“紧凑型-中心性”模式,制造业则形成了以国家级新区和产业园区为空间载体的“离散型-郊区化”模式。③ 生产性服务业与制造业企业的区位选择需在产业环境、要素禀赋以及政策导向方面进行权衡,生产性服务业企业较为关注区域整体发展氛围,制造业企业则更注重自然因素、区位历史和产业政策的影响。④ 传统型生产性服务业企业区位选择受到地方化经济、区位资源禀赋的影响最为显著,现代型和高端型生产性服务业企业则更容易受到政策的导引从而形成空间集聚;劳动密集型制造业企业主要依附在劳动力资源较为丰富且交通便利的地区,资本密集型制造业企业倾向于具有产业政策优势及土地成本优势的开发区和新区布局,技术密集型制造业企业受成本要素的制约较小且更加注重集聚经济的外部效用。     

基于Geoserver和Leaflet的地理信息服务构建与调用

GIS是地理信息服务的有效工具和手段。本文基于开源GIS软件Geoserver和Leaflet,首先,介绍了它们的特点和优势,阐述了地理信息服务的规范;然后,提出了构建与调用地理信息服务的体系框架,研究了服务构建和调用等关键技术;最后,基于烟台市地图数据进行实验,取得了满意的效果。