Identifying and assessing the residency effect in Pocatello,Idaho, using combined census and parcel data

Human residency is the spatial effect source on ecosystem and thus it should be studied and assessed. Supporting residency effect research, this study developed and applied procedures and a model to combine census and parcel data for the assessment. The case study is in Pocatello, Idaho, where revealing land service associated with flood control and locating/evaluating resident effect are needed. Methods include (1) data mining, (2) land service valuation, (3) data screening, (4) integration of census and parcel data, (5) data screening, and (5) analysis and modeling with R programing language and ArcMap. Results are, for land service assessment, land value per area unit in residence areas (LAND) along the concrete channel (for flood control) was less than that along the Portneuf River. Spatial responses under LAND to a source effect (either the concrete channel or the river) are the same. The applied methods helped locate and assess a variety of residency effects spatio-temporally. Results informed the human preferences under LAND and the effect distribution to support decision-making. Technically, using the parcels as a baseline provided comprehensive results with a fine resolution for the effect study, particularly as combined with the census data. This study suggests using a data screening and validation procedure besides the mining approach to minimize outcome uncertainty.     

基于Oracle拓扑模型的地块建模与变更

拓扑建模是实现地籍地块变更的基础。通过以Oracle10g拓扑数据模型结点创建界址点,弧段创建界址线,多边形创建地块的方法实现了地籍地块的拓扑建模,减化了拓扑规则的设置及拓扑错误的检查,提出了地籍地块的变更方法,给出了其具体的实现过程和关键技术。     

基于空间填充曲线排列码划分的并行缓冲区算法

缓冲区计算是地理信息系统空间分析的基本功能之一。在矢量缓冲区研究方面,以往大多聚焦缓冲区生成算法,这些优化方法在单机计算环境中针对大规模空间数量数据的计算效率提升是有限的,因而需要并行环境下的改进方法来进一步破解计算瓶颈。本文基于Map Reduce计算模型和分布式内存计算框架,提出了一种基于空间填充曲线排列码划分的并行缓冲区分析算法(SPBM),基于空间填充曲线编码进行数据排序和范围划分,对跨越网格的数据采用近似切分方法,在考虑负载均衡的前提下对任务并行分解,之后按照给定深度的"树状"方式进行结果合并。本文在单机和集群两种环境下利用实际道路网等数据进行了实验。同等环境下,相较于目前流行的GIS软件——QGIS和Post GIS计算性能提升明显,相较于现有其他并行优化方法效率提升超过50%。这样的优化分析方法对于GIS中其他矢量分析算法的并行算法也具有一定的借鉴意义。     

Introducing scale parameters for adjusting area objects in GIS based on least squares and variance component estimation

In this paper, a least‐squares based cadastral parcel area adjustment in geographic information systems (GIS) is developed based on (1) both the areas and coordinates being treated as observations with errors; and (2) scale parameters being introduced to take the systematic effect into account in the process of cadastral map digitization. The area condition equation for cadastral parcel considerations of scale parameters and geometric constraints is first constructed. The effects of the scale error on area adjustment results are then derived, and statistical hypothesis testing is presented to determine the significance of the scale error. Afterwards, Helmert's variance component estimation based on least‐squares adjustment using the condition equation with additional parameters is proposed to determine the weight between the coordinate and area measurements of the parcel. Practical tests are conducted to illustrate the implementation of the proposed methods. Four schemes for solving the inconsistencies between the registered areas and the digitized areas of the parcels are studied. The analysis of the results demonstrates that in the case of significant systematic errors in cadastral map digitization, the accuracies of the adjusted coordinates and areas are improved by introducing scale parameters to reduce the systematic error influence in the parcel area adjustment. Meanwhile, Helmert's variance component estimation method determines more accurate weights of the digitized coordinates and parcel areas, and the least‐squares adjustment solves the inconsistencies between the registered areas and the digitized areas of the parcels.     

德州市德城区地籍调查数据整理入库工作探讨

全国第二次土地调查是一项重大的国情国力调查,在此次调查中笔者负责德城区调查成果数据入库。该文基于在第二次土地调查中的工作经验,就扫描档案文件、宗地权属信息和宗地界址信息快速整理入库提出几点方法,供广大一线工作者参考。     

PRB数字地质填图前期数据准备及PRB过程字典库建立

PRB数字地质填图前期数据准备包括软硬件准备、地形图数值化、前人资料的收集和室内录入、多元数据的叠加和整合、PRB过程字典库的编制等方面.PRB过程字典库由结构化字典、填缺式字典和描述性字典3部分组成.结构化字典和填缺式字典可直接查询, 为1~1.5级字典, 描述性字典为2级字典, 需要2级查询.不同的字典类型均以文本文档的形式存在, 文件名后缀为.DIC.      

珠江三角洲城市群污染综合指数预报的模式方法

应用全二阶矩表示的商斯烟团模式,重点引入烟团的合并与分解及各种清除过程,并利用广州热带模式（GZTM）所提供的华南地区细网格的三维数字化流场,来计算污染物浓度的长期变化。具体先模拟计算SO2、NOx、TSP的地面浓度日变化,通过求平均得到每种污染物的日均浓度,并和对应的污染物的日均浓度二级标准比较,得到每种污染物的污染指数Pi,最后求和得出污染综合指数P,从而对珠江三角洲地区的污染综合指数作出预报。     

低压倒槽影响下积层混合云形成过程模拟研究

利用多普勒雷达资料和中尺度天气预报模式wRF（Weather Research and Forecasting）模拟结果,对2009年5月9—10日发生在太原及其周边地区的一次积层混合云降水形成过程进行分析。结果表明,在积层混合云的形成初期,局地对流云得到发展,随着其强度不断增强,与周围云发生并合过程（包括局地单体对流的并合、积云团的并合和积层混合云内强中心的并合）,形成范围较大的积层混合云云系。局地单体对流和积云团的并合可带来云体的爆发性增长,霰含量、雨水含量大幅增加。积层混合云内强中心的并合对降水强度影响不大,但有利于降水面积扩大。低压倒槽和弱冷锋是此次积层混合云形成和维持的主要影响因素。低压倒槽有利于低层大范围不稳定能量的积累,风向切变有利于近距离云团的发展和并合,山地动力和热力作用有利于局地对流单体、积层混合云内强中心的形成和加强。     

Simulating urban land-use changes at a large scale by integrating dynamic land parcel subdivision and vector-based cellular automata

Cellular automata (CA) have been widely used to simulate complex urban development processes. Previous studies indicated that vector-based cellular automata (VCA) could be applied to simulate urban land-use changes at a realistic land parcel level. Because of the complexity of VCA, these studies were conducted at small scales or did not adequately consider the highly fragmented processes of urban development. This study aims to build an effective framework called dynamic land parcel subdivision (DLPS)-VCA to accurately simulate urban land-use change processes at the land parcel level. We introduce this model in urban land-use change simulations to reasonably divide land parcels and introduce a random forest algorithm (RFA) model to explore the transition rules of urban land-use changes. Finally, we simulate the land-use changes in Shenzhen between 2009 and 2014 via the proposed DLPS-VCA model. Compared to the advanced Patch-CA and RFA-VCA models, the DLPS-VCA model achieves the highest simulation accuracy (Figure-of-Merit = 0.232), which is 32.57% and 18.97% higher respectively, and is most similar to the actual land-use scenario (similarity = 94.73%) at the pattern level. These results indicate that the DLPS-VCA model can both accurately split the land during urban land-use changes and significantly simulate urban expansion and urban land-use changes at a fine scale. Furthermore, the land-use change rules that are based on DPLS-VCA mining and the simulation results of several future urban development scenarios can act as guides for future urban planning policy formulation.     

径向行星际磁场下的场向电流的统计学研究

基于CHAMP卫星高精度磁场观测数据,对2001—2009年径向行星际磁场(RIMF, radial interplanetary magnetic fields)条件下的场向电流的分布特征进行了统计学分析, 并与2001—2009年期间场向电流的平均强度进行了对比研究, 结果表明：正午时刻场向电流的平均强度对地偶极子倾角有明显线性依赖, 冬夏季电流强度比值约为3左右, RIMF条件下冬夏季比值降为2;相对年平均值来说, RIMF条件下行星际磁场总幅度、重联电场、太阳风动压均有所减小, AE指数减弱, Dst指数略有降低;在通常情形下重联电场是场向电流很好的控制参数, 但是在RIMF下, 重联电场不再与电流强度相关;北半球电流强度在向地IMF条件下大于向日IMF, 而南半球则相反, 虽然RIMF条件下场向电流的均值小于年平均值, 但是正午时段场向电流强度大于年平均值的概率大约为0.2, RIMF条件下仍然有地磁扰动事件(比如亚暴事件)发生。