Synergetic efficiency of Lidar and WorldView-2 for 3D urban cartography in Northeast Mexico     

Fabiola D. Yépez Rincón  Diego F. Lozano García 《国际地球制图》2019,34(2):164-178

Three-dimensional urban cartography is needed for city changes’ assessment. The variety of studies using 3D calculations of urban elements grows each year. Building and vegetation volumes are necessary to assess and understand spatio-temporal urban changeable environments. However, there are technical questions as to which method can improve 3D urban cartographic accuracy. The innovative part of this current study is the creation of a six-band hybrid obtained from LIDAR and WorldView2 synergy. Two different enhancement algorithms demonstrated the most important spectral features for the urban development and vegetation classes. Results indicated an improvement in accuracy by up to 21.3%, according to the Kappa coefficient. Both infra-red band and intensity band were the most significant, according to the principal components analysis. The synergy delimited classes and polygons, as well as the direct display of information regarding heights of elements and improving the extraction of roads, buildings and vegetation classes.  相似文献   

The Three American Wests     

Joe Weber 《The Professional geographer》2019,71(2):239-252

In the twenty-first century, there are three American Wests, which cut across cultural, political, physical, and economic boundaries. Parts of the West are booming, building homes, and adding population; others are legally off limits to such development; and much of the West has been bypassed by such development and growth. These are called here the Booming West, Protected West, and Bypassed West. Maps of climate, political boundaries, ethnic and racial identities, or presidential voting patterns do not match these three Wests. Each West has a different relationship to the others and might see them as threats or opportunities, and each West can be expected to grow in different areas at the expense of other Wests. The boundaries between the three Wests could be important locations; sharp transitions can exist between Wests, perhaps nowhere more so than where a fast growing metro area abuts a national park or forest boundary. Finally, the effects of climate change cut across the three Wests and have different implications for their future. Continued population growth will further emphasize the boundaries between each of the three Wests and raise the stakes for their control.  相似文献   

Spatial distribution characteristics of national protected areas in China     

Xu  Baicui  Pan  Jinghu 《地理学报(英文版)》2019,29(12):2047-2068

Journal of Geographical Sciences - This paper investigated spatial structures of 3418 national protected areas (NPAs) grouped into 13 types using GIS and quantitative analysis, including point...  相似文献   

利用水准数据的天津市地面沉降时空特征分析     

常明  尹海权  苏广利  田晓  徐玉健 《测绘通报》2020,(7):88-92

地面不均匀沉降可能对城市的发展与人民的安全造成危害，天津市的地面沉降情况尤为严重。针对该问题，本文收集天津市2005—2012年、2016—2017年水准观测数据，以固定水准点位的沉降量、沉降速率、沉降加速率为状态向量，构建卡尔曼滤波模型，对天津市历年的水准观测数据进行滤波；根据滤波后的结果，本文利用多项式加权内插的方法，以距离、沉降速率、沉降加速率信息确定权值大小，对地面沉降情况进行内插；并以中误差作为精度评定参数，比较多种内插方法的精度。通过对内插结果的试验分析发现，2005—2017年天津市地面累计平均沉降量为394.477 5 mm，最大沉降量为1 143.5 mm；主要沉降区域为北辰、大港、塘沽等地区，且随着时间的增长，这些区域呈现漏斗式下沉。试验证明本文结合卡尔曼滤波与多项式加权内插的方式能够较好地反映地面沉降的时空特征分布情况并对未来一段时间的沉降情况进行预测，对天津市的城市发展及建设有一定的参考意义。  相似文献   

最优权组合预测法在采煤沉陷变形预测中的应用   总被引：1，自引：0，他引：1  

鲁小红 《测绘通报》2020,(4):111-115

煤矿地表沉降变形预测多基于煤矿开采沉陷预计理论展开，基于变形分析理论的变形预测模型目前多集中在单模型预测。本文基于组合预测思想，以非等间隔灰色预测模型与BP神经网络模型为预测单模型，以陕西北部某煤矿采煤工作面上方实测地表沉降值为数据源，以最优加权法对单模型预测结果开展了最优权组合，组合模型中两种单模型的权重分别为0.466 7、0.533 3。选取部分监测点的预测结果进行模型精度评价，结果表明：3种预测模型精度均达到了一级。经对比3种模型预测结果，最优权组合预测的模型精度较单模型明显提升，预测结果较非等间隔灰色预测模型与BP神经网络预测模型有明显增益。  相似文献   

Advances and Practices on the Research, Prevention and Control of Land Subsidence in Coastal Cities     

YAN Xuexin  YANG Tianliang  XU Yan  Luigi TOSI  Esther STOUTHAMER  Heri ANDREAS  Philip MINDERHOUD  Anirut LADAWADEE  Ramon HANSSEN  Gilles ERKENS  Pietro TEATINI  LIN Jinxin  Roberta BONì  Jarinya CHIMPALEE  HUANG Xinlei  Cristina Da LIO  Claudia MEISINA  Francesco ZUCCA 《《地质学报》英文版》2020,94(1):162-175

Land subsidence severely threatens most of the coastal plains around the world where high productive industrial and agricultural activities and urban centers are concentrated. Coastal subsidence damages infrastructures and exacerbates the effect of the sea-level rise at regional scale. Although it is a well-known process, there is still much more to be improved on the monitoring, mapping and modeling of ground movements, as well as the understanding of controlling mechanisms. The International Geoscience Programme recently approved an international project (IGCP 663) aiming to bring together worldwide researchers to share expertise on subsidence processes typically occurring in coastal areas and cities, including basic research, monitoring and observation, modelling and management. In this paper, we provide the research communities and potential stakeholders with the basic information to join the participating teams in developing this project. Specifically, major advances on coastal subsidence studies and information on well-known and new case studies of land subsidence in China, Italy, The Netherlands, Indonesia, Vietnam and Thailand are highlighted and summarized. Meanwhile, the networking, dissemination, annual meeting and field trip are briefly introduced.  相似文献   

全球海潮模型最新进展及在中国沿海精度评估     

范长新 《大地测量与地球动力学》2019,39(5):476-481

介绍TPXO、FES、Chinatide、MIKE Global Tide、Utide等典型海潮模型，总结归纳其同化潮汐数据来源和最新的海洋地形数据，利用我国沿岸长期验潮站以外的26个中短期潮位观测站评估TPXO等海潮模型预报精度。结果表明，全球海潮模型对我国沿海M2分潮的预报精度普遍较低，且主导了几种海潮模型在中国海域的整体预报精度；相比MIKE Global Tide和TPXO7.2,TPXO8、TPXO_Yellow Sea 2010和TPXO_China&Ind模型在我国沿海的预报精度更高。  相似文献   

Inverse modelling using PS‐InSAR data for improved land subsidence simulation in Las Vegas Valley,Nevada          下载免费PDF全文

Meijing Zhang  Thomas J. Burbey 《水文研究》2016,30(24):4494-4516

Las Vegas Valley has had a long history of groundwater development and subsequent surface deformation. InSAR interferograms have revealed detailed and complex spatial patterns of subsidence in the Las Vegas Valley area that do not coincide with major pumping regions. This research represents the first effort to use high spatial and temporal resolution subsidence observations from InSAR and hydraulic head data to inversely calibrate transmissivities (T), elastic and inelastic skeletal storage coefficients (S_ke and S_kv) of the developed‐zone aquifer and conductance (CR) of the basin‐fill faults for the entire Las Vegas basin. The results indicate that the subsidence observations from InSAR are extremely beneficial for accurately quantifying hydraulic parameters, and the model calibration results are far more accurate than when using only groundwater levels as observations, and just a limited number of subsidence observations. The discrepancy between distributions of pumping and greatest levels of subsidence is found to be attributed to spatial variations in clay thickness. The Eglington fault separates thicker interbeds to the northwest from thinner interbeds to the southeast and the fault may act as a groundwater‐flow barrier and/or subsidence boundary, although the influence of the groundwater barrier to this area is found to be insignificant. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   

南水北调地下水回补对潮白河冲洪积扇中上部地表形变响应及控制因素     

田苗壮 《地质论评》2024,70(1):2024010006-2024010006

2014年南水进京后,持续开展地下水回补对于遏制和减缓地面沉降发展起到重要作用,但地下水回升由此带来的不同区域、不同层位的地面沉降与回弹机制及其控制因素尚不明确。深入探讨和研究回补时间、回补量、回补地点与水位及地表形变之间的关系,了解地表形变发生机理和识别主控因素,为后续如何科学回补,发挥最大化水资源回补效益、对地面沉降防治和超采区治理具有极其重要意义。本文以潮白河冲洪积扇中上部区域为例,采用永久散射体差分干涉测量（PS InSAR）技术获取研究区地面沉降形变信息,并结合区域分层地下水位动态变化、分层沉降变化等多手段进行耦合,查明研究区地表形变与多因素之间的响应与控制因素。结果表明:南水持续回补导致区域地面沉降减缓,并在牛栏山地区出现地表抬升,抬升范围也随着水位上升逐渐向中下游扩展,2022年最大回弹速率达46.9 mm/a;地表形变具有明显的受断裂所控制的第四系沉积差异特性,以黄庄—高丽营断裂、顺义断裂和南口—孙河断裂所分割的后沙峪凹陷范围内变化明显大于其他地区;地下水位变幅与富水性差异决定水位上升范围与响应变化,而沉积构造作用所造成第四系沉积差异在地下水流向上具有一定控制作用。结果为地面沉降防控和机理研究提供理论和科学依据,同时也为后续开展地下水科学回补和方案优化提供指导和借鉴。  相似文献   

Trace element and REE geochemistry of fine- and coarse-grained sands in the Ordos deserts and links with sediments in surrounding areas   总被引：1，自引：0，他引：1  

Wenbo Rao  Hongbing Tan  Sanyuan Jiang  Jiansheng Chen 《Chemie der Erde / Geochemistry》2011,(2):155-170

In addition to mineral analyses, REE and trace element geochemical characteristics of fine- and coarse-grained sands in the Ordos deserts and other sediments in surrounding areas are investigated.Commonly the samples consist of quartz, feldspar and muscovite and less clinochlore, dolomite and ankerite. In few samples muscovite is absent.REE and trace compositions are spatially uniform for the same grain-size sands, suggesting that they could have the same sources or/and were well homogenized. However, fine- and coarse-grained sands in the Ordos deserts show different REE and trace element compositions. Fine-grained sands show higher contents of REE and trace elements than those of coarse-grained sands. They differ in Eu anomalies and (La/Yb)_N ratios although both fractions are characterized by the steep LREE and smooth HREE patterns. The fine- and coarse-grained sands are also distinct in some characteristic element ratios (e.g., Th/Co, La/Sc, Th/Sc and Y/Ni).REE and trace element patterns of the two different grain-size fractions are closely associated with geological properties of individual sources rather than the mineralogical differentiation induced by wind sorting. The coarse-grained sands mainly resulted from sandstone weathering in the Ordos deserts and movements of coarse particles by wind. REE and trace element patterns of fine-grained sands in the Ordos deserts differ from those of sandstones in the Ordos deserts, the alluvial sands in the surrounding mountains and the coarse fluvial sands in the Yellow River. They resemble the fine fluvial sands in the Yellow River. In addition, arid areas of Northwest China such as the Tarim Basin and the Alxa Plateau should not be ruled out as the source of the fine-grained sands in the Ordos deserts because these arid areas reserve plenty of fine-grained sediments and also located in the upwind directions of the Ordos deserts.  相似文献