Automatic selection of weights for GIS-based multicriteria decision analysis: site selection of transmission towers as a case study

Transmission line (TL) siting consists of finding suitable land to build transmission towers. This is just one of the numerous complex geographical problems often solved using GIS-based multicriteria decision analysis (MCDA), which is a set of techniques that weight several geographical features to identify suitable locations. This technique is mostly employed using expert knowledge to identify the correct set of weights; thus adding a certain amount of subjectivity to the analysis, meaning that for the same problem if we change the experts involved, we may reach different results.This research is a first attempt to try and solve this issue. We employed a statistical analysis to quantitatively calculate these weights and we tested our method on a case study about transmission line siting in Switzerland. We compared the distances between each sample in our dataset, in this case study these are location of transmission towers, with each geographical feature, e.g. distance from water features. Then we calculate the same distances but for random points, sampled throughout the study area. The reasoning behind this method is that if samples present a distance from a geographic feature statistically different from the random, it means that the feature played an important role in dictating the location of the sample. In this case for instance, high-voltage transmission towers are purposely built as far away as possible from urban areas. Random points are on the contrary by definition sampled without any constraint. Therefore, when comparing the two datasets, we should find that transmission towers have a larger average distance from urban areas than random points. This allows us to determine that this criterion (i.e. distance from urban centers) is important for planning new TL.The results indicate that this method can successfully weight and rank the most important criteria to be considered for an MCDA analysis, in line with weights proposed in the literature. The advantage of the proposed technique is that it completely excludes human factors, thus potentially increasing the social acceptance of the MCDA results.     

基于OWA的大理市土地生态安全评价研究

从自然生态环境角度出发,从自然因子、生态环境因子、景观因子3个层面选取16项评价指标建立大理市土地生态安全评价体系,并运用IDRISI软件中的MCE模块进行有序加权平均算子（OWA）多准则决策评价,得到不同决策风险系数下的大理市土地生态安全评价结果。结果显示,由于决策者风险态度不同,得到土地生态安全评价结果差异较大,在实际应用中,必须结合研究区的实际情况以及规划的目的选择不同的风险系数进行评价,才能得到更加真实有效的结果。     

基于“推拉阻”模型的国内亲子旅游决策研究

亲子旅游是国内近年来迅速升温的旅游形式,但国内对该领域的研究非常匮乏。基于"推拉"动机理论,构建"推拉阻"模型应用于亲子旅游决策研究。采用SPSS 21.0对319份有效问卷进行统计,亲子旅游决策的影响因素按照重要性依次是推力、拉力和阻力。通过因子分析得到2项推力动机("孩子主导型"和"家长主导型")、4项拉力动机("设施完善""环境优良""特色服务"和"主题鲜明")、2项阻力因子("小孩因子"和"时间与费用因子")。其中,"增加亲子感情""旅游行程安排轻松愉快"和"家长没有足够的闲暇时间"分别是最重要的推力、拉力和阻力变量。单因素方差分析显示,小孩数量与阻力的"小孩因子"呈显著正相关,小孩年龄与拉力动机的"环境优良"存在显著的正相关,家长学历对推力动机的"家长主导型"和拉力动机的"环境优良"均产生显著影响。     

中国东中西部城市土地储备决策绩效比较研究

运用数据包络分析(DEA)模型,对2013年中国内地34个大中城市土地储备决策绩效进行总体评价和比较分析。研究结果表明:东部地区城市土地储备决策效率最高,西部次之,中部最低;土地储备决策效率受到纯技术效率和规模效率的共同作用,且规模效率作用较大;影响东中西部城市土地储备决策效率投入产出的主要因素各不相同。基于此,从深化土地及相关制度改革和提升政府管理效率两个层面提出土地储备决策绩效优化策略,从而提高土地资源利用效率、优化城市空间结构。     

湘江新区土地利用结构多目标规划及决策偏好分析

土地利用规划需要综合考虑经济效益和生态效益。构建了经济最大化和生态效益最大化2个目标,并运用基于模糊集理论的最大(小)算子法求得兼顾经济效益和生态效益的土地利用模糊最优规划方案。随后重点探讨了不同决策偏好情景下的土地利用优化方案和综合效益的变化。研究结果表明:(1)对经济效益和生态效益的偏好程度不同,主要会导致林地、城镇建设用地和水域面积发生变化;(2)随着决策者对生态效益偏好程度的增加,城镇建设用地面积逐渐减少,林地和水域面积逐渐增加;(3)当经济效益比生态效益重要时,最优的用地规划方案主要是在城镇用地和水域面积之间进行权衡;当生态效益比经济效益重要时,最优的用地规划方案主要是在林地和城镇建设用地之间进行权衡。研究结果对湘江新区进行"资源节约型和环境友好型社会"建设中的多目标土地利用规划具有一定的决策参考价值。     

Arps递减开发模型

本文在Ａｒｐｓ递减产能预测模型的基础上提出了Ａｒｐｓ递减开发模型,提出了开发速度,采出程度等开发指标的数学关系式,分析了参数Ａｒｐｓ递减开发模型的影响,提出了开发初期Ａｒｐｓ递减开发模型的确定方法,便于开发初期决策,制作了Ａｒｐｓ递减开发模型的ｌｏｇＶｄ－ｌｏｇＲｐ图版,ｌｏｇＶｄ－ｌｏｇ（Ｄｔ）图版,ｌｏｇＲｐ－ｌｏｇ（Ｄｔ）图版,提出了开发中晚期Ａｒｐｓ递减开发模型的判断方法,三点抛物线法和三     

Differences in flood hazard projections in Europe – their causes and consequences for decision making

This paper interprets differences in flood hazard projections over Europe and identifies likely sources of discrepancy. Further, it discusses potential implications of these differences for flood risk reduction and adaptation to climate change. The discrepancy in flood hazard projections raises caution, especially among decision makers in charge of water resources management, flood risk reduction, and climate change adaptation at regional to local scales. Because it is naïve to expect availability of trustworthy quantitative projections of future flood hazard, in order to reduce flood risk one should focus attention on mapping of current and future risks and vulnerability hotspots and improve the situation there. Although an intercomparison of flood hazard projections is done in this paper and differences are identified and interpreted, it does not seems possible to recommend which large-scale studies may be considered most credible in particular areas of Europe.

EDITOR D. Koutsoyiannis

ASSOCIATE EDITOR not assigned     

IM‐based and EDP‐based decision models for the verification of the seismic collapse safety of buildings

Decision models for the verification of seismic collapse safety of buildings are introduced. The derivations are based on the concept of the acceptable (target) annual probability of collapse, whereas the decision making involves comparisons between seismic demand and capacity, which is familiar to engineering practitioners. Seismic demand, which corresponds to the design seismic action associated with a selected return period, can be expressed either in terms of an intensity measure (IM) or an engineering demand parameter (EDP). Seismic capacity, on the other hand, is defined by dividing the near‐collapse limit‐state IM or EDP by an appropriate risk‐targeted safety factor (γ _im or γ _edp ), which is the only safety factor used in the proposed decision model. Consequently, the seismic performance assessment of a building should be based on the best possible estimate. For a case study, it is shown that if the target collapse risk is set to 10^?4 (0.5% over a period of 50 years), and if the seismic demand corresponds to a return period of 475 years (10% over a period of 50 years), then it can be demonstrated that γ _im is approximately equal to 2.5 for very stiff buildings, whereas for buildings with long periods the value of γ _im can increase up to a value of approximately 5. The model using γ _edp is equal to that using γ _im only if it can be assumed that displacements, with consideration of nonlinear behavior, are equal to displacements from linear elastic analysis.     

基于植被物候特征的互花米草提取方法研究——以长三角湿地为例

互花米草自1979年引进我国以来迅速增长,呈现外来物种入侵势态,严重影响了滨海湿地生态系统平衡。通过遥感手段监测可以获取互花米草的时空扩展规律,为互花米草治理提供参考和依据。本文选取长三角地区3个主要湿地区域为研究区,依托Google Earth Engine (GEE)平台选取了2014—2019年Landsat 8 OLI时间序列数据,提出了一种基于物候特征的互花米草提取方法。首先,通过归一化差异湿度指数(NDMI)、归一化差异植被指数(NDVI)和归一化差异水体指数(NDWI)提取互花米草生长的高湿度区域;然后,通过植被指数构建表征植被物候特征的时间序列曲线,确定互花米草与其他植被的物候特征差异时相;最后,基于物候特征差异时相数据构建决策树提取互花米草。通过与现有的互花米草决策树提取方法和支持向量机(SVM)方法对比发现,本文方法在3个研究区的提取结果均为最优提取结果,表明本文的方法对提取互花米草具有较好的适用性。     

防汛决策指挥地理信息系统构建关键问题研究

根据陕西渭河下游流域现有资料、防汛实际应用需求及未来发展趋势,对基础地理、防汛专题等空间静态数据及水雨情等实时信息进行整合处理和有效集成,并基于开放性的面向服务的B/S架构体系理念以及空间和属性数据一体化、多源数据无缝集成的建库思想,开展了融信息实时监测、三维决策支持、地图查询定位、防汛预案展示、信息采编维护等为一体的流域防汛决策指挥地理信息系统的构建以及系统架构设计、数据组织处理、数据建库优化、地图缓存配置、数据共享交换等关键问题研究,可对提高流域防汛决策管理能力、减少洪涝灾害损失及构建人水和谐环境提供有力保障。