省尺度森林植被碳储量空间分布模拟不确定性分析——以江西省为例（英文）     

王轶夫  岳天祥  雷渊才  杜正平  赵明伟 《地理学报(英文版)》2016,26(5):568-584

Forest vegetation carbon patterns are significant for evaluating carbon emission and accumulation. Many methods were used to simulate patterns of forest vegetation carbon stock in previous studies, however, uncertainty apparently existed between results of different methods, even estimates of same method in different studies. Three previous methods, including Atmosphere-vegetation interaction model 2(AVIM2), Kriging, Satellite-data Based Approach(SBA), and a new method, High Accuracy Surface Modeling(HASM), were used to simulate forest vegetation carbon stock patterns in Jiangxi Province in China. Cross-validation was used to evaluate methods. The uncertainty and applicability of the four methods on provincial scale were analyzed and discussed. The results showed that HASM had the highest accuracy, which improved by 50.66%, 33.37% and 28.58%, compared with AVIM2, Kriging and SBA, respectively. Uncertainty of simulation of forest biomass carbon stock was mainly derived from modeling error, sampling error and statistical error of forest area. Total forest carbon stock, carbon density and forest area of Jiangxi were 288.62 Tg, 3.06 kg/m~2 and 94.32×109 m~2 simulated by HASM, respectively.  相似文献   

Mosaicing of airborne LiDAR bathymetry strips based on Monte Carlo matching     

Fanlin Yang  Dianpeng Su  Kai Zhang  Yue Ma  Mingwei Wang  Anxiu Yang 《Marine Geophysical Researches》2017,38(3):303-311

This study proposes a new methodology for mosaicing airborne light detection and ranging (LiDAR) bathymetry (ALB) data based on Monte Carlo matching. Various errors occur in ALB data due to imperfect system integration and other interference factors. To account for these errors, a Monte Carlo matching algorithm based on a nonlinear least-squares adjustment model is proposed. First, the raw data of strip overlap areas were filtered according to their relative drift of depths. Second, a Monte Carlo model and nonlinear least-squares adjustment model were combined to obtain seven transformation parameters. Then, the multibeam bathymetric data were used to correct the initial strip during strip mosaicing. Finally, to evaluate the proposed method, the experimental results were compared with the results of the Iterative Closest Points (ICP) and three-dimensional Normal Distributions Transform (3D-NDT) algorithms. The results demonstrate that the algorithm proposed in this study is more robust and effective. When the quality of the raw data is poor, the Monte Carlo matching algorithm can still achieve centimeter-level accuracy for overlapping areas, which meets the accuracy of bathymetry required by IHO Standards for Hydrographic Surveys Special Publication No.44.  相似文献   

多源数据协同的城市道路提取     

邓凯  杨灿灿  尹力  赵明伟  江岭  彭道黎 《测绘通报》2021,(10):60-66,82

城市道路的高精度提取可为城市三维表达、城市地形分析、城市建设规划、交通导航等提供数据基础和支撑。本文以合肥市局部城区为试验区,以开源路网、街景图像和遥感影像为数据源,在利用最大似然法进行初提取的基础上,通过空间分析、统计分析、几何量测、最小二乘拟合等方法进行粘连分割、缺失处理和交叉口细化等关键处理,构建了多源数据协同的城市道路提取方法,并对提取结果进行了精度评价和分析。试验结果表明,本文提出的城市道路提取方法优于最大似然和面向对象方法,提取总体精度为96.65%,Kappa系数为93.71%,道路宽度偏离标准差为0.03m,特别是对同物异谱、同谱异物及遮挡等造成的信息提取不全问题具有良好的改善效果。  相似文献   

Investigation of the 2019 Wenchuan County debris flow disaster suggests nonuniform spatial and temporal post-seismic debris flow evolution patterns     

Zhang  Xianzheng  Tang  Chenxiao  Li  Ning  Xiong  Jiang  Chen  Ming  Li  Mingwei  Tang  Chuan 《Landslides》2022,19(8):1935-1956

Landslides - It is widely recognized that post-seismic mass movements amplify and decay. Previous studies have found that most post-seismic mass movement is concentrated in the first few years...  相似文献   

Spatial and temporal variation process of seabed dynamic response induced by the internal solitary wave     

Zhuangcai Tian  Lei Jia  Naili Hu  Susheng Wang  Mingwei Zhang  Guoqing Zhou 《海洋学报(英文版)》2023,42(2):142-149

Internal solitary wave(ISW) is often accompanied by huge energy transport, which will change the pore water pressure in the seabed. Based on the two-dimensional Biot consolidation theory, the excess pore water pressure in seabed was simulated, and the spatiotemporal distribution characteristics of excess pore water pressure was studied. As the parameters of both ISW and seabed can affect the excess pore water pressure, the distribution of pore water pressure showed both dissipation and phase lag...  相似文献   

The rotated Cartesian coordinate method to remove the axial singularity of cylindrical coordinates in finite‐difference schemes for elastic and viscoelastic waves          下载免费PDF全文

Mingwei Zhuang  Jianyang Zhou  Songlin Wei  Qing Huo Liu 《Geophysical Prospecting》2018,66(Z1):27-39

When modelling the propagation of 3D non‐axisymmetric elastic and viscoelastic waves in cylindrical coordinates using the finite‐difference time‐domain method, a mathematical singularity occurs due to the presence of terms in the elastic and viscoelastic wave equations. For many years, this issue has been impeding the accurate numerical solution near the axis. In this work, we propose a simple but effective method for the treatment of this numerical singularity problem. By rotating the Cartesian coordinate system around the z‐axis in cylindrical coordinates, the numerical singularity problems in both 2D and 3D cylindrical coordinates can be removed. This algorithm has three advantages over the conventional treatment techniques: (i) the excitation source can be directly loaded at , (ii) the central difference scheme with second‐order accuracy is maintained, and (iii) the stability condition at the axis is consistent with the finite‐difference time‐domain in Cartesian coordinates. This method is verified by several 3D numerical examples. Results show that the rotating the Cartesian coordinate method is accurate and stable at the singularity axis. The improved finite‐difference time‐domain algorithm is also applied to sonic logging simulations in non‐axisymmetric formations and sources.  相似文献   

基于OCO-2卫星观测模拟高精度XCO2的空间分布     

张丽丽  赵明伟  赵娜  岳天祥 《地球信息科学学报》2018,20(9):1316-1326

本文首次基于OCO-2卫星观测数据,采用高精度曲面建模（High Accuracy Surface Modeling, HASM）的方法来模拟大范围高精度的二氧化碳柱浓度（XCO₂）的空间分布。首先,探讨分析HASM方法应用于模拟OCO-2卫星观测XCO₂的空间分布的可行性。从2014年9月至2015年8月OCO-2观测的12个月的XCO₂数据中,分别随机选取其各个月90%的XCO₂数据用于空间插值,剩余10%作为精度验证点。自验证结果表明,12个月的平均绝对值误差为0.34 ppm。由此可见,HASM适用于模拟OCO-2卫星观测XCO₂的空间分布。然后,采用HASM对OCO-2在2014年9月至2015年8月的各个月观测数据进行空间插值,获取空间分辨率为0.5°×0.5°的各个月均值XCO₂的空间分布,同时基于地基观测TCCON( Total Carbon Column Observing Network)站的XCO₂数据对HASM模拟结果进行交叉验证。验证结果表明,HASM模拟的XCO₂与TCCON站对应观测数据相比,其平均绝对值误差为0.81 ppm,相关系数为0.88。因此,HASM在模拟OCO-2卫星观测的XCO₂空间分布上具有很大的优势。  相似文献   

鄂尔多斯盆地东南部气田上古生界致密砂岩气藏气源对比          下载免费PDF全文

聂万才  白玉奇  冯敏  张晨  张波  王铭伟 《沉积与特提斯地质》2021,41(1):82-87

本文通过碳同位素数据比对、常规天然气组分分析,结合区域地质背景,对鄂尔多斯盆地东南部气田的气源进行了研究.结果表明:鄂尔多斯盆地东南部气田的主力烃源岩为煤层,含气层位出现碳同位素倒转现象,山西组山2段和本溪组主要为煤型气中混入少量油型气,而山西组山1段和石盒子组盒8段则是成藏期经历了多期充注所导致;CH4、CO2和iC...  相似文献   

北京休闲农业与乡村旅游发展研究   总被引：19，自引：0，他引：19  

郭焕成  孙艺惠  任国柱  吕明伟 《地球信息科学学报》2008,10(4):453-461

休闲农业与乡村旅游在我国已经有20多年的发展历史。北京作为最早开始发展休闲农业与乡村旅游的城市,具备良好的农业资源条件和旅游发展环境。至2007年底,北京全市实际经营的农业观光园达到1302个,观光园总收入13.1亿元,农业观光园和民俗旅游户接待人数达到2614.4万人次,休闲农业与乡村旅游的发展呈现勃勃生机。目前北京休闲农业与乡村旅游发展主要有农业观光休闲、民俗文化休闲、休闲度假三大类型;地域布局呈现近郊、中郊平原区、远郊山区三大圈层结构;与风景旅游区相结合,形成十大发展基地。"十一五"期间,北京市提出重点打造五条农业精品旅游专线,必将进一步推进观光休闲农业与乡村旅游的健康发展。本文从发展条件、发展现状和特点、发展布局、旅游线路组织等几个方面,对北京市休闲农业与乡村旅游的发展进行了全面、系统的分析和总结,并在此基础上提出了北京市休闲农业与乡村旅游发展对策与建议:合理布局、科学管理、加大投入、强化培训、加强法律保障。  相似文献   

机载LIDAR数据的树高识别算法与应用分析   总被引：1，自引：0，他引：1  

王轶夫  岳天祥  赵明伟  杜正平  刘向锋  刘爽  宋二非  孙文正  张彦丽 《地球信息科学学报》2014,16(6):958-964

利用机载激光雷达数据提取天然次生林的树高,旨在探索影响树高提取精度的主要因素。首先,采用高精度曲面建模平差算法(Adjustment Computation of High-accuracy Surface Modeling,HASM-AD)生成研究区不同空间分辨率的数字高程模型(Digital Elevation Model,DEM)、数字地表模型(Digital Surface Model,DSM)和冠层高度模型(Canopy Height Model,CHM);其次,用树顶点识别算法提取林木树高,设置不同树高识别范围,对比分析不同CHM分辨率和不同树高识别范围对树高提取精度的影响;最后,以天涝池流域30个实测样地数据为样本,对提取精度进行检验。结果显示：提取的样地平均树高与实测值具有明显线性相关关系,线性回归系数为0.694;树高识别范围是影响树高提取精度的重要因素,CHM分辨率对其影响较小。研究表明,采用高采样密度的雷达点云数据、正确选择CHM生成方法和改进树顶点识别算法是提高天然次生林树高提取精度的有效途径。  相似文献