古地貌演化对洛阳盆地新石器中晚期至夏商时期水稻种植的影响

水稻是起源于中国南方长江流域的重要农作物,新石器中期以后传播到北方地区。由于北方较于南方相对干旱,因此对水分条件需求较高的水稻在北方地区的种植往往表现为更强烈的地域选择性。本文选取中原地区地形特征较为复杂的洛阳盆地开展了流域调查和浮选工作,结合前人在本区做的炭化植物遗存研究成果,分析了新石器中晚期至夏商时期洛阳盆地不同地貌部位水稻（Oryza sativa）遗存的分布特征,再根据本区平原区和黄土台塬沟谷区全新世地貌演化的不同特点,探讨了古地貌演化对洛阳盆地史前水稻种植的影响。研究表明,裴李岗文化时期暂未发现水稻遗迹,平原区湖沼遍布,不适宜人类居住,古人可能更倾向于居住在黄土台塬沟谷区的稳定阶地面上;仰韶文化晚期古稻主要分布在黄土台塬沟谷区,与当时沟谷区河流夹积形成的富含粘土的湿润冲积平原有关,而此时平原区距今7000~4000年为稳定干燥的T₁阶地面,更适合发展粟（Setaria italica）作农业;龙山时期没有在沟谷区发现水稻遗存,可能与距今4000年前后沟谷区河流下切侵蚀导致的泛滥平原减少有关,而龙山晚期在伊洛河平原区的遗址发现了古稻遗存,推测与龙山晚期降水增多和洪水频发,出现较多水洼低地有关;二里头时期,古稻在平原区和黄土台塬区都有分布且遗址数量较多,可能与距今4000~3800年龙山晚期古洪水事件后,洪水退去遗留的低洼地有关;二里头和二里岗时期,盆地内古稻遗址普遍增多,平原区古稻遗址可能占更大比重,推测可能与古地貌特征、人类文化自身发展,以及农田管理技术的进步等均有关系。

     

珠江三角洲区域一体化研究综合信息系统的设计与应用

在分析地理信息系统技术发展与应用现状的基础上,设计了珠江三角洲区域一体化研究综合信息系统的结构框架。根据珠江三角洲的实际情况,并在经济地理学,城市地理学,区域科学等理论的指导下,开发了针对该区域一体化研究的模型分析系统。基于元数据库的数据集成与模型管理技术,能对不同数据源,不同数据类型与时空特性的多元数据处理与分析。本综合信息系统在区域产业布局,资源窨组合,城市体系空间结构演化等方面得到应用,将为     

中国省际工业生态效率空间分布及影响因素研究

将中国30省市（不含港、澳、台和西藏地区）作为研究对象,进行省际工业生态效率空间分布及影响因素研究。首先构建中国省际工业生态效率评价指标体系,其次利用DEA-BCC模型结合Malmquist指数对2006~2015年中国30省市在时空两个维度上的工业生态效率进行测算,再次运用Geoda软件分析中国工业生态效率的空间分布特征,最后通过空间误差模型对中国工业生态效率的影响因素进行检验。研究结果表明：① 中国工业生态效率虽呈现小幅度下降趋势,但整体效率水平较高;30省市之间存在明显差异性,呈现出东部>中部>西部的分布格局。② 中国工业生态效率Malmquist指数增长率水平较高;30省市Malmquist指数均为正向增长,呈现出稳定增长趋势;技术进步效率是Malmquist指数的主要推动力。③ 中国30省市工业生态效率呈现正向空间自相关性,且存在明显的集聚状态,近邻效应显著。④ 中国省际工业生态效率的主要影响因素有经济发展水平、产业结构、政府规制、技术进步、外商投资和产业集聚。     

班公湖-怒江带、羌塘地块特提斯演化与成矿地质背景

早古生代—泥盆纪,研究区沉积环境以陆棚碎屑岩相和碳酸盐台地相为主,代表冈瓦纳大陆北缘和特提斯南侧的被动大陆边缘。石炭纪—二叠纪,本区进入特提斯南、北缘弧盆系统演化阶段,龙木错-双湖带北部、金沙江带南部和冈底斯带分别在石炭纪、二叠纪形成岩浆弧。中生代是特提斯南缘弧盆演化阶段,SSZ型蛇绿岩形成岩浆熔离型铬、镍、铂族金属矿床和热液型金矿。班公湖-怒江带特提斯在中侏罗世至早白垩世向南、北两侧俯冲并形成岩浆弧,该岩浆弧是重要的成矿带,形成斑岩铜矿、矽卡岩型磁铁矿和热液型多金属矿床。北羌塘东段侏罗纪弧后前陆盆地有利于形成沉积型、沉积-热液改造型和热液型铁、铜、锑、金矿床。晚白垩世碰撞作用主要与热液型矿床有关,分布范围较大,也可能存在晚白垩世至新生代碰撞阶段的斑岩铜矿。     

青藏高原羌塘地区果干加年山—荣玛乡一带石炭纪—二叠纪古生物研究新进展

在羌塘中部大沙河-果干加年山剖面展金岩群中发现珊瑚化石赫氏鲍斯维耳剌毛虫Chatetes(Boswellia)heritschi Sokolov,说明展金岩群中存在晚石炭世的生物时代证据。但是该化石并不是属于冈瓦纳冷水生物区的,而是来自温水环境的特提斯型生物区。在荣玛乡黑石山剖面中发现大量中二叠世 科化石,既出现典型的冈瓦纳相冷水生物,如Wannerophyllam 、Monodiexodina等,也存在大量暖水型的生物,如田氏朱森 Chusenella tieni Chen、散尔多希瓦格 Schwagerina sanerduoensis Nieet Song、假孙氏假纺锤 Pseudofusulina pseudosuni Sheng等。化石特征属于冈瓦纳相与特提斯相的混合类型。研究表明,羌塘中部的喀喇昆仑—龙木错—双湖一带是石炭纪、二叠纪冈瓦纳和特提斯生物混生区,不存在明显的生物大区界线。推测龙木错-双湖蛇绿岩带所代表的洋盆可能仅为特提斯南缘弧盆系统中的小盆地。     

西安城市扩张及其驱动力分析

随着人口的增长与经济的发展,尤其我国西部城市在西部大开发的背景下,大中城市的扩张十分明显,深刻地影响城市周边的生态环境。如何快速准确地获取城市扩张信息,并分析其驱动力机制,对于指导城市规划,优化西部生态环境与可持续发展都具有十分重要的意义。作者分别采用了监督分类法和归一化裸露指数 (NDBI) 法提取了西安市的城市边界信息,并对二者进行对比分析,认为监督分类法提取的城市边界信息较为准确。在此基础上通过对相关统计资料的分析,认为西安市城区快速扩张与西部大开发以来西安市固定资产投资额的大幅增加以及经济的快速发展有密切的关系,此外人口的增加、交通等基础设施的发展也是重要的驱动因素。     

An enhanced approach for surface flow routing over drainage‐constrained triangulated irregular networks

The accuracy and efficiency of the simulations in distributed hydrological models must depend on the proper estimation of flow directions and paths. Numerous studies have been carried out to delineate the drainage patterns based on gridded digital elevation models (DEMs). The triangulated irregular network (TIN) has been increasingly applied in hydrological applications due to the advantages of high storage efficiency and multi‐scale adaptive performance. Much of the previous literature focuses mainly on filling the depressions on gridded DEMs rather than treating the special cases in TIN structures, which has hampered its applications to hydrological models. This study proposes a triangulation‐based solution for the removal of flat areas and pits to enhance the simulation of flow routing on triangulated facet networks. Based on the drainage‐constrained TIN generated from only a gridded DEM by the compound point extraction (CPE) method, the inconsistent situations including flat triangles, V‐shape flat edges and sink nodes are respectively identified and rectified. The optimization algorithm is an iterative process of TIN reconstruction, in which the flat areas are generalized into their center points and the pits are rectified by embedding break lines. To verify the proposed algorithm and investigate the potential for flow routing, flow paths of steepest descent are derived by the vector‐based tracking algorithm based on the optimized TIN. A case study of TIN optimization and flow path tracking was performed on a real‐world DEM. The outcomes indicate that the proposed approach can effectively solve the problem of inconsistencies without a significant loss in accuracy of the terrain model.     

Mapping hourly dynamics of urban population using trajectories reconstructed from mobile phone records

Understanding the spatiotemporal dynamics of urban population is crucial for addressing a wide range of urban planning and management issues. Aggregated geospatial big data have been widely used to quantitatively estimate population distribution at fine spatial scales over a given time period. However, it is still a challenge to estimate population density at a fine temporal resolution over a large geographical space, mainly due to the temporal asynchrony of population movement and the challenges to acquiring a complete individual movement record. In this article, we propose a method to estimate hourly population density by examining the time‐series individual trajectories, which were reconstructed from call detail records using BP neural networks. We first used BP neural networks to predict the positions of mobile phone users at an hourly interval and then estimated the hourly population density using log‐linear regression at the cell tower level. The estimated population density is linearly correlated with population census data at the sub‐district level. Trajectory clustering results show five distinct diurnal dynamic patterns of population movement in the study area, revealing spatially explicit characteristics of the diurnal commuting flows, though the driving forces of the flows need further investigation.     

Extraction of Alteration Mineral Information from Moderate Remote Sensing Images Using MPS Method

Although alteration minerals related to metallogenesis is very important in mineral exploration, information of alteration mineral is weakly expressed in remote sensing imagery, which is often subject to interfering noise and sometimes limited in spectral and spatial resolutions. Because of easy access, moderate images are the main sources of alteration mineral information. Therefore, it is very important to develop alteration mineral information extraction methods from remote sensing images. In this paper, a combined method based on Mask, principal component analysis (PCA) and support vector machine method (SVM) was used to extract alteration mineral information from Enhanced thematic mapper plus remote sensing data with limited spectral and spatial resolutions. First, a mask image of the remote sensing imagery was created to remove interference information such as vegetation, shadow and water. Then, PCA was employed to collect sample data relating to iron, argillic, and carbonatization alteration. Finally, SVM was used to deal with alteration anomaly and build a feature extraction model of high accuracy. The Mask-PCA-SVM model is used to extract alteration mineral information from remote sensing images of Hatu area, Xinjiang Uygur Autonomous Regions, China. The results show that the new methods proposed in this paper can coincide well with known deposits occurrences, rate reached 86.51%. While, the consistent rate with known deposits of the ratio model, PCA model and Spectral angle mapper model were only 3.37, 65.08 and 69.05% respectively. This suggests that the proposed model can find the actual distribution of mineral deposits more effectively by reducing interference to a greater degree.     

Analysis of the Seasonal Variation of CO<Subscript>2</Subscript> Concentration in China Based on GOSAT Satellite Data

Carbon dioxide (CO₂) is one of the major gases that contribute to the global warming. Therefore, studying the distribution of CO₂ can help people understand the carbon cycle. Based on the GOSAT retrieved CO₂ products, the temporal and spatial distribution and seasonal variation of CO₂ concentration were analyzed from 2011 to 2015. CO₂ concentration has obvious seasonal variation. It was low in summer, and was high in spring, and the annual increase was about 2 ppm. Nevertheless, the annual growth rate of CO₂ concentration in summer was higher than that in spring, it was 0.5425% in summer and was 0.46% in spring. CO₂ concentration was low in the northwest and was high in the southeast. The growth rate of CO₂ was 2.8 ppm in the northwest and was 3.42 ppm in the southeast. More human’s activities made CO₂ concentration higher in the southeast than that in other regions.