A landscape pattern analysis method based on boundaries and nodes: A case study in upper Minjiang River, China

Traditionally,patch-based analysis at the landscape scale fragmentation has been used in the study of landscape ecology while the study of boundary and node has not been considered as much detail until recently.This study investigated the possibility of applying boundary-and node-based methods in landscape pattern analysis to the upper reaches of the Minjiang River in the southwestern China.Boundary-based and node-based landscape indices were selected to be used in analyzing changes in landscape patterns,and the results were compared with analysis using traditional pattern indices.We compared the responses of patch-area-based,boundary-length-based and node-number-based indices,and concluded that boundary-based and node-based indices are more sensitive to disturbance than patch-based indices with various patterns,and node-based indices are even more sensitive than boundary-based ones.Thus,the results suggest that boundary-based and node-based pattern analysis methods provide helpful supplementary information to traditional patch-based pattern analysis methods.The results about pattern dynamics of landscapes in the upper reaches of the Minjiang River based on boundaries and nodes showed that with human disturbance,the dominance of forest landscape was weakened by other landscape types; thus the landscape pattern of the study area became more homogeneous and the boundary network became more complex.These changes further augmented disturbance interfaces in the landscape and increased the possibilities of further landscape fragmentation.     

Spatial heterogeneity of soil mineral oxide components in depression between karst hills,Southwest China

In karst regions,the spatial heterogeneity of soil mineral oxides and environmental variables is still not clear.We investigated the spatial heterogeneity of SiO2,Al2O3,Fe2O3,CaO,MgO,P2O5,K2O,and MnO contents in the soils of slope land,plantation forest,secondary forest,and primary forest,as well as their relationships with environmental variables in a karst region of Southwest China.Geostatistics,principal component analysis(PCA),and canonical correlation analysis(CCA)were applied to analyze the field data.The results show that SiO2was the predominant mineral in the soils(45.02%–67.33%),followed by Al2O3and Fe2O3.Most soil mineral oxide components had a strong spatial dependence,except for CaO,MgO,and P2O5in the plantation forest,MgO and P2O5in the secondary forest,and CaO in the slope land.Dimensionality reduction in PCA was not appropriate due to the strong spatial heterogeneity in the ecosystems.Soil mineral oxide components,the main factors in all ecosystems,had greater influences on vegetation than those of conventional soil properties.There were close relationships between soil mineral oxide components and vegetation,topography,and conventional soil properties.Mineral oxide components affected species diversity,organic matter and nitrogen levels.     

2012年成都市PM10污染与地面气象条件的相关性分析

为了解2012年成都市PM10浓度分布情况及其与地面气象条件的相关性,通过分析2012年PM10浓度的分布情况,选取了13次污染过程,并对这些过程中的地面气象要素情况进行分析。结果表明,PM10浓度呈波状分布,其中3月和11月分别达到峰值,7月为全年最低;过程期间各变量具有以下特征:PM10浓度与温度呈正相关,与气压呈负相关,当有降温升压时PM10浓度减小;24小时变压变温都较小,表明天气较稳定;地面风速小,普遍小于2m/s,且主要为弱偏西偏北风,而当风速增大时有利于PM10的扩散;低能见度与较大的相对湿度对应较好,二者有明显的负相关。     

济南新火车东站及轨道交通建设对济南白泉泉群的影响分析

近年来,随着经济的快速发展和城市的大规模建设,济南市的泉水保护与经济建设产生了一些矛盾。根据规划,济南市拟在白泉泉域的周边建设济南新火车东站、地下轨道交通等项目,项目建设将会对白泉泉群的喷涌产生影响,根据野外实际调查成果,从白泉泉群的补、径、排角度分析了项目建设对泉群产生的影响,提出在保护泉群的前提下进行新火车站及轨道交通建设的合理化建议。     

特征约束六面体网格生成的改进栅格法

目前,针对地学对象的非结构化六面体网格生成问题仍未得到很好的解决。为满足相关地学研究对六面体网格的需求,促进地学模拟及传统GIS空间分析的进一步发展,本文对传统栅格法进行扩展,提出了一种面向地学研究的六面体网格生成的改进栅格法。通过提取实体模型表面的几何特征,考虑内部孔、洞约束生成骨干网格,在此基础上构建一套特征约束模板来处理复杂的特征约束,使之既能保持地学研究对象的几何形态特征,又能实现加密区域与非加密区域的平滑过渡,从而满足地学分析与模拟的需求。     

广东汛期蒸发皿蒸发量变化趋势及气象影响因子的通径分析

选取广东省86个气象观测站的观测资料,采用气候趋势分析和通径分析方法,对广东省1961～2003年小型蒸发皿蒸发量及其相关气象影响因子进行了分析。结果表明:虽然汛期广东省整体平均蒸发量呈下降趋势,前汛期、后汛期线性倾向率分别为-15.86 mm/10a和-13.79 mm/10a;但变化趋势在广东省内空间分布并不均匀,前汛期、后汛期粤东、中部部分地区分别有16、12个站呈上升趋势;前汛期6种气象因子单独对蒸发的决定程度按大小依次为:日照时数>气温>风速>降水>饱和差>气温日较差,后汛期6种气象因子单独对蒸发的决定程度按大小依次为:日照时数>降水>饱和差>风速>气温>气温日较差,整个汛期日照时数与其它各要素的协同作用对蒸发皿蒸发量的决定作用都很大。日照时数和风速总体上的下降是导致广东省汛期蒸发皿蒸发量逐年减少的重要原因。     

K-means算法复杂度的能量分析方法

传统的算法复杂度分析方法重点对算法的内在流程进行分析,而且对于数据挖掘时具有很大不确定性,执行时间不能准确确定.用物理学原理从能量的角度对数据挖掘中的经典聚类算法K-means进行分析,并从算法的本质上推导出其复杂度下限,推导出该算法能优化到的极限值.     

矿物收藏漫谈(七)矿物收藏者的秘密

<正>通过前面的介绍,现在我们已经了解要在矿物收藏的天地里畅游所需注意的7个方面的问题。下面要谈谈不同类型的矿物收藏者。有一种级别的收藏者和经销商只对高     

关于我省土地整理复垦开发项目数据库建设的设想

一、数据库应用中常用空间分析方法 1．矢量数据空间分析 矢量数据空间分析包括属性量算和分析、空间缓冲区分析、空间叠置分析以及空间格局分析。     

Blasius方程中临界值的分析估计

证明了流体力学边界层理论中著名的Blasius方程的一个新性质,它在二维平板流的研究中具有重要的作用,由此建立它的积分形式,并给出方程中的临界值βc的分析估计。