三维激光扫描技术在桥梁构件模拟预拼装中的应用     

罗永权  张鸿飞 《测绘与空间地理信息》2017,40(11)

提出了一种以三维激光扫描仪为主要数据获取手段,针对大型桥梁构件的模拟预拼装方法,用于装配化施工生产项目中大型构件的质量控制,并取代传统的、需要在构件加工场内搭建脚手架进行现场立体拼接来检验构件加工质量的方法。项目实践结果表明:该模拟预拼装方法建模方法快捷、有效,模型配准精度较高,建立的三维模型真实,能有效检验构件的质量,指导构件的场内修正,为推动装配化施工的市场进程提供技术支撑。  相似文献   

线性参照系在城市交通事故发布系统中的作用及应用     

罗京 《测绘与空间地理信息》2017,(1)

针对城市交通部门事故管理系统中存在道路数据不独立以及发布的事故信息易读性差导致应急部队无法准确定位事故地点进行救援的问题,基于公路的线性特征,结合GIS对地理数据的多样操作功能,提出路段名+特征参考点的一维定位表达方法。将线性参照系理论应用到以综合车道为公路模型的空间数据管理模式中,建立基于线性参照系的城市公路事故信息发布系统,实现二维坐标向一维坐标转换、降低数据冗余、实现事故地点的快速定位以及对定位的事故信息进行发布。  相似文献   

基于流量监测的西藏东南部然乌湖水量平衡季节变化及其补给过程分析   总被引：1，自引：0，他引：1  

崔颖颖  朱立平  鞠建廷  罗伦  王永杰 《地理学报》2017,72(7):1221-1234

青藏高原分布着亚洲大陆最大的湖泊群,其湖泊变化对气候变化响应敏感。基于遥感数据的湖泊面积变化不足以反映外流湖对气候变化的响应,需借助湖泊水量平衡过程分析来进一步研究各补给要素的变化。本文利用2015年4月-11月然乌湖水文气象监测数据,通过建立流量—水位关系,依据连续的水位数据重建了观测期内然乌湖主要径流的水文过程线,并结合SRM模型分析了然乌湖的水量平衡过程及季节变化。结果表明,观测期内然乌湖入湖水量约为18.49×10⁸ m³,其中冰川融水约为10.06×10⁸ m³,冰川融水占然乌湖补给的54%以上,湖面降水、湖面蒸发对湖泊水量平衡过程影响微弱。流域降水对湖泊的补给具有明显的季节特征。春季受西风南支扰动影响,然乌湖地区降水量大,降水是春季然乌湖的主要补给源。夏季和早秋由于气温升高,冰川消融量大,冰川融水是湖泊补给的主控因素。在未来气候变暖的条件下,冰川融水将会在湖泊补给中占据更大比例,并可能使得流域内的冰湖水量增加,产生潜在灾害风险。  相似文献   

基于冠层温度的作物缺水研究进展   总被引：35，自引：2，他引：35  

袁国富  唐登银  罗毅  于强 《地球科学进展》2001,16(1):49-54

冠导温度信息可以很好地反映作物的水分状况。自20世纪70年代以来，基于冠层温度的作物缺水指标的研究经历了三个阶段，即单纯研究冠层温度本身变化特征的第一阶段、以冠层能量平衡原理为基础的作物水分胁迫指数的第二阶段和考虑冠层和土壤的复合温度的水分亏缺指数的第三阶段。指标的局长也由使用手持式红外辐射仪信息扩大到使用航空和卫星遥感信息。这一类指标在点和区域尺度上均可应用。加强这一类指标的研究对于我国北方地区农作物的有效灌溉和区域水资源的管理都有重要意义。  相似文献   

Elements and Element Components of the Rural Landscape in Linpan of Western Sichuan in Relation to Perception,Preference and Stress Recovery     

LUO Hao  DENG Li  JIANG Songlin  FU Erkang  MA Jun  SUN Lingxia  JIANG Mingyan  CAI Shizhen  JIA Yin  CAI Jun  LI Xi 《资源与生态学报(英文版)》2021,12(3):384-396

Natural environments contribute to people’s perception, preference and health restoration. Many researchers have focused either on the positive effects of overall rural environments on stress recovery or concentrated on the perception and preference aspects of the rural landscape, but few have integrated perception, preference and stress recovery simultaneously. This paper developed a framework which includes 11 elements and 38 element components related to Linpan, China, and distributed it online as part of a survey. As a result, a total of 324 valid questionnaires were collected. The questionnaire included demographic details, perception and preference degree for Linpan, as well as self-estimations of stress recovery. Stepwise multiple linear regression was employed, and revealed 16 significant predictors for the perception, preference and stress recovery in rural environments. In terms of elements, atmosphere and imagery were the two elements that could be best perceived, while woodland, farmland, water, residence and road were the five most important elements for the preference. Moreover, seven elements were also identified as significant predictors for stress recovery. Among the element components, tranquility as well as road and water proximity were the two significant predictors for perception, while wide visibility as well as woodland and residence blending contributed significantly to stress recovery. The five element components of woodland interior, vegetable field, stream, courtyard space and branch road each had a significantly predictive ability for preference and stress recovery. These findings extend the understanding of the perception, preference and restorative properties of rural environments through the combination of elements and element components in Linpan of Western Sichuan, helping to improve the quality and characteristics of rural external and internal environments and create health-promoting environments.  相似文献   

Ecological Footprint Evaluation of Three Types of Wood Flooring in China based on Their Production Data from 2000 to 2018     

LI Jianquan  YUAN Yue  LUO Shuzheng 《资源与生态学报(英文版)》2021,12(3):430-436

To encourage the environmental responsibility of consumers and manufacturers for forest management, it is necessary to evaluate the environmental influences of forest products. Ecological footprint (EF) is an internationally recognized indicator for estimating the natural capital consumption and environmental influences of various forest products. In this study, we developed an accounting model for the EF evaluation of wood flooring, which is a tertiary forest product, by the method of transformation. Next, we used that model to evaluate the EF of three types of wood flooring in China according to their production data from 2000 to 2018. We collected the necessary data by visiting typical enterprises in China and referring to the relevant literature. According to our results, the average EFs of solid wood flooring, engineered solid wood flooring and laminate flooring between 2000 to 2018 were 3.13×10 ⁶, 1.05×10 ⁷ and 5.07×10 ⁶gha, respectively. The total EFs of solid wood flooring, engineered solid wood flooring and laminate flooring from 2000 to 2018 were 5.95×10 ⁷, 1.99×10 ⁸and 9.64×10 ⁷gha, respectively. The coefficients of variation (CV) of the EFs for these three types of wood flooring were 0.45, 0.87 and 0.76, respectively. The average and total EFs of the engineered solid wood flooring were the largest among the three types of wood flooring. The per capita EF and unit EF for the engineered solid wood flooring were also the highest among the three types of wood flooring. The EFs showed an upward trend with irregular fluctuations from 2000 to 2018 for all three types of wood flooring. It is necessary to reduce the EF of the engineered solid wood flooring and use more environmentally friendly products, such as solid wood flooring, for environmental protection.  相似文献   

中国城市地表灰尘中重金属的富集状况及空间分布特征   总被引：1，自引：0，他引：1  

王硕  蔡立梅  王秋爽  罗杰  唐翠华  穆桂珍  蒋慧豪  刘天勇 《地理研究》2018,37(8):1624-1640

在统计中国城市地表灰尘中重金属含量的已有相关文献基础上,探讨了中国地表灰尘中Cr、Cu、Pb、Zn、Cd五种元素的空间分布特征及各省份的富集状况。搜集到的各地区地表灰尘重金属含量的研究数据分别为69、84、86、79、58个。对研究数据剔除异常值后分别进行克里金插值和统计各省份地表灰尘重金属含量的平均值,并与土壤背景值作对比计算出累积指数,得到中国地表灰尘中重金属的空间分布状况和各省份的富集水平。结果表明：中国地表灰尘中重金属含量普遍较高,且各地区重金属含量水平存在不同程度上的差异。就整体而言,Cu、Pb、Zn三种重金属含量的空间分布较为相似,由高到低均大致呈南—北走势,而Cr含量呈中部高两侧低的趋势,Cd并无明显趋势。各省份平均值与土壤背景值相比,除Cr在山东省和贵州省无富集状况以外,各省的地表灰尘中Cu、Pb、Zn、Cd均具有一定的富集。其中,湖南省的Cd和Pb均富集最为严重,分别是土壤背景值的177.95和42.82倍;Cr在福建省富集最为严重,为背景值的7.11倍;广东省的Cu富集水平最高,是背景值的10.35倍,而Zn在江西省的富集水平最高,超出背景值39.13倍。  相似文献   

土地管理三维思维与土地空间资源认知   总被引：1，自引：0，他引：1  

郭仁忠  罗平  罗婷文 《地理研究》2018,37(4):649-658

基于城市发展的三维理念轨迹及土地立体化利用趋势,采用文献检索与综合分析法,剖析土地管理重视三维思维的原因,辨析土地的空间特质,提出土地空间资源的概念内涵,初探土地空间资源管理制度和技术,以促进土地领域实践问题解决。结果显示：① 土地管理三维思维符合社会发展和土地利用趋势,是基于土地管理实践而衍生的创新需求。② 土地作为资源的本质属性之一是空间性,具备三维空间特质;土地空间资源是土地资源概念的外延,是以土地表层为基底或脱离土地表层的可利用的三维空间存在。③ 土地空间资源的提出,能引发土地管理领域在理念、制度和技术上进行三维思维化的重构与创新,具有科学意义和实践价值。  相似文献   

Ecosystem Carbon Allocation of a Temperate Mixed Forest and a Subtropical Evergreen Forest in China     

LUO Yiwei  ZHANG Leiming  GUO Xuebing  DAI Guanhua  WANG Anzhi  ZHOU Guoyi  YU Guirui 《资源与生态学报(英文版)》2018,9(6):642-653

Ecosystem carbon allocation can indicate ecosystem carbon cycling visually through its quantification within different carbon pools and carbon exchange. Using the ecological inventory and eddy covariance measurement applied to both a mature temperate mixed forest in Changbai Mountain (CBM) and a mature subtropical evergreen forest in Dinghu Mountain (DHM), we partitioned the ecosystem carbon pool and carbon exchange into different components, determined the allocation and analyzed relationships within those components. Generally, the total carbon stock of CBM was slightly higher than that of DHM due to a higher carbon stock in the arbor layer at CBM. It was interesting that the proportions of carbon stock in vegetation, soil and litter were similar for the two mature forests. The ratio of vegetation carbon pool to soil carbon stock was 1.5 at CBM and 1.3 at DHM. However, more carbon was allocated to the trunk and root from the vegetation carbon pool at CBM, while more carbon was allocated to foliage and branches at DHM. Moreover, 77% of soil carbon storage was limited to the surface soil layer (0-20 cm), while there was still plentiful carbon stored in the deeper soil layers at DHM. The root/shoot ratios were 0.30 and 0.25 for CBM and DHM, respectively. The rates of net ecosystem productivity (NPP) to gross ecosystem productivity (GPP) were 0.76 and 0.58, and the ratios of ecosystem respiration (Re) to GPP were 0.98 and 0.87 for CBM and DHM, respectively. The net ecosystem carbon exchange/productivity (NEP) was 0.24 t C ha^-1 yr^-1 for CBM and 3.38 t C ha^-1 yr^-1 for DHM. Due to the common seasonal and inter-annual variations of ecosystem carbon exchange resulting from the influence of environmental factors, it was necessary to use the long record dataset to evaluate the ecosystem sink capacity.  相似文献   

Relationships between Genetic Diversity of Vascular Plant Species and Climate Factors     

TAN Jingfang  WAN Jizhong  LUO Fangli  YU Feihai 《资源与生态学报(英文版)》2018,9(6):663-672

Genetic diversity is crucial for plants to respond to global climate change, and exploring relationships between genetic diversity and climatic factors may help predict how global climate change will shape the genetic diversity of plants in the future. So far, however, the extent and magnitude of the impact of climatic factors on the genetic diversity of plants has not been clarified. We collected data from 68 published papers on two widely used measures of genetic diversity of populations (average expected heterozygosity (He) and average observed heterozygosity (Ho)) and on localities of populations of 79 vascular plants, and extracted data on 19 climatic factors from WorldClim. We then explored the relationships between measures of genetic diversity and climatic factors using linear regressions. He of plant populations was significantly correlated with climatic factors in 58.7% (44) of the 75 species that used He as a measure of genetic diversity, and Ho was correlated with climatic factors in 65.1% (41) of the 63 species that used this genetic diversity measure. In general, Mean Temperature of Wettest Quarter, Precipitation Seasonality, Precipitation of Driest Quarter and Temperature Seasonality played a vital role in shaping He, and Ho was mostly correlated with Precipitation of Warmest Quarter, Mean Temperature of Wettest Quarter, Precipitation of Driest Quarter and Precipitation of Driest Month. Also, the proportion of the significant correlations between genetic diversity of populations and climatic factors was higher for woody than for herbaceous species, and different climatic factors played different roles in shaping genetic diversity of these two growth forms. Our results suggest that climate may play an important role in shaping genetic diversity of plant populations, that climatic change in the future may alter genetic diversity of plants, and that genetic diversity of different plant forms may respond to climatic change differently.  相似文献