Snake Model for the Extraction of Loess Shoulder-line from DEMs   总被引：1，自引：0，他引：1  

YAN Shi-jiang  TANG Guo'an  LI Fa-yuan  ZHANG Lei 《山地科学学报》2014,(6):1552-1559

Shoulder lines are the most important landform demarcations for geographical analysis,soil erosion modeling and land use planning in the Loess Plateau area of China.This paper proposes an automatic,effective and accurate method of determining loess shoulder line from DEMs by integrating a hydrological D8 algorithm and a snake model.The watershed boundary line is adopted as the initial contour which evolves to identify the exact position of loess shoulder-line by the guidance of an external force of snake model from DEMs.Experiments show that the method overcomes the difficulties in both threshold selection for edge detection and the disconnecting issues in former extraction approaches.The accuracy evaluation of shoulder-line maps from the two test sites of the loess plateau area show obvious improvements in the extraction.The average contour matching distance of the new method is 12.0 m on 5 m resolution DEM,and shows improvement in the accuracy and continuity.The comparisons of accuracy evaluations of the two test sites show that the snake model method performs better in the loess plain area than in the area with high gully density.  相似文献   

基于景观格局指数的基本农田保护区集中连片性研究——以济南市历城区为例   总被引：1，自引：0，他引：1       下载免费PDF全文

张保华  王雷  白振华  潘庆龙  汤庆新  肖燕 《山东国土资源》2014,30(2):80-82

耕地与基本农田保护是我国土地管理、土地利用规划的重要内容。新一轮土地利用总体规划修编及数据库建设中要求基本农田调整布局更加集中连片。该文应用景观格局指数,研究了济南市历城区基本农田保护区规划调整中集中连片性的变化。结果表明,除保护区图斑面积标准差外,图斑平均面积、图斑面积变异系数、图斑边界密度、最大斑块指数、平均欧式邻近距离5项指标均表明,规划调整后基本农田保护区布局上更加集中连片。为基本农田保护区布局的集中连片性判断提供了简便易行的方法。  相似文献   

潍坊市土地整治规划环境影响评价          下载免费PDF全文

唐伟  孟艳丽  白杨  丁喜莲 《山东国土资源》2014,30(8)

从选取评价土地整治规划环境影响评价指标体系的原则入手,构建了2大方面、6大因素共计17项具体指标量化环境影响,通过综合分值来确定土地整治规划的实施对环境的具体影响,为整治规划的实施以及环境的保护提供参考。  相似文献   

渤海海峡亚海鲂属鱼类一新记录种——云纹亚海鲂     

朱龙 《广东海洋大学学报》2014,(3):1-4

2012年12月3日,在渤海海峡的蓬莱近海浅水海域捕获雄性成体鱼1尾,该鱼体长34 cm,体高18cm,体长为体高的1.9倍,体宽4.5 cm,头长12.5 cm,体长为头长的2.7倍,尾柄长4.5 cm,体光滑无鳞。管状侧线前半部弧形,后半部平直,行于体中央。棘状骨板沿背鳍基底两侧各12块,臀鳍基底两侧各8块,每一骨板中央具1棘,向后;胸部6块,自第3骨板开始分左右两行;腹部7块,自第2骨板开始分左右两行,胸腹部骨板棘小,形成锯齿缘。背鳍1个,鳍棘部与鳍条部之间有一深缺刻;鳍棘细长,棘间鳍膜延长成丝状,最长超过尾鳍末端。据其形态特征和测量值,鉴定为云纹亚海鲂(Zenopsis nebulosa Temminck et Schlegel,1847),为该海域首次记录。  相似文献   

基于SDCORS的车载RTK高程注记点连续采集精度分析          下载免费PDF全文

凌晓春  刘石栋  刘振军  汤玉兵 《山东国土资源》2014,30(5)

为提高航测法数字线划图(DLG)的生产效率,尽可能减少外业作业时间,基于山东省卫星定位连续运行综合服务系统(SDCORS)的车载RTK技术进行高程注记点采集。采用不同时间(白天、晚上)、不同车速条件进行高程注记点连续采集,并与常规方法(全站仪、单基站RTK)采集高程点进行比较,求取高程中误差,认为在夜间以不大于20 km/h的车速进行采集精度较高。在数字海阳基础地理信息数据采集项目中,利用车载RTK采集346 km2范围内的沿路高程注记点,结果表明能够满足1∶500航测法成图精度要求。  相似文献   

黑龙江老柞山金矿床地质、地球化学特征及其成矿构造背景     

李明飞  叶松青  杨言辰  张国宾  侯晓光  明添学  唐忠 《世界地质(英文版)》2014,(3)

在对老柞山矿床地质特征系统研究的基础上,对与成矿有关的岩石开展了进一步的主、微量元素地球化学测试分析。结果显示与成矿有关的花岗岩具富Sr、低Ti的高钾钙碱性火山弧花岗岩的特征,闪长玢岩具偏铝质钙碱性岩系列特征。岩石样品均呈现出富集轻稀土元素和大离子亲石元素（LILEs）、相对亏损重稀土元素和Nb、 Ta、 Ti等高场强元素（ HFES）的特征,显示了与岛弧或活动大陆边缘岩浆岩相似的属性。流体包裹体特征显示,成矿流体主要来自岩浆水,矿床具中低温（125.6℃～324.5℃）、中浅成（1.0～7.1 km）成矿的特点。与成矿有关岩浆岩显示幔源岩浆特征,可能是地幔交代作用部分熔融所形成的。结合区域上同时期的火成岩时空展布认为,老柞山金矿床成矿可能分别与晚古生代古亚洲洋板块北向俯冲作用和中生代太平洋板块俯冲作用密切相关。  相似文献   

莺歌海盆地前新生代基底特征     

尤龙  王璞珺  吴景富  岳军培  郎元强  沈怀磊 《世界地质(英文版)》2014,(3)

结合盆缘露头、盆地基底钻井及重磁震资料,综合研究莺歌海盆地前新生代基底特征。基于盆地西北缘Song Da带18个剖面点地层序列、166件岩石样品密度和2800套磁化率测量结果,建立密度--磁化率交汇图版,约束盆内地震剖面和重磁异常解释,通过海陆结合的方法填制出盆地基底地质图。其前新生界由前震旦系、寒武系-上三叠统下部、上三叠统上部-白垩系三个构造层构成,它们沿红河断裂呈北西向分布,中间老,为前震旦纪中-高级变质岩;两侧新,向西为中生代沉积岩,向东为古生代浅变质岩、灰岩。  相似文献   

Spatial-temporal patterns of China’s interprovincial migration, 1985-2010     

LI Yang  LIU Hui  TANG Qing  LU Dadao  XIAO Ningchuan 《地理学报》2014,24(5):907-923

Migration plays an increasing role in China's economy since mobility rose and economic restructuring has proceeded during the last three decades. Given the background of most studies focusing on migration in a particular period, there is a critical need to analyze the spatial-temporal patterns of migration. Using bicomponent trend mapping technique and interprovincial migration data during the periods 1985-1990, 1990-1995, 1995-2000, 2000-2005, and 2005-2010 we analyze net-, in-, out-migration intensity, and their changes over time in this study. Strong spatial variations in migration intensity were found in China's interprovincial migration, and substantial increase in migration intensity was also detected in eastern China during 1985-2010. Eight key destinations are mostly located within the three rapidly growing economic zones of eastern China (Pearl River Delta, Yangtze River Delta and Beijing-Tianjin-Hebei Metropolitan Region), and they are classified into three types: mature, emerging, and fluctuant origins, while most key origins are relatively undeveloped central and western provinces, which are exactly in accordance with China's economic development patterns. The results of bicomponent trend mapping indicate that, in a sense, the migration in the south was more active than the north over the last three decades. The result shows the new changing features of spatial-temporal patterns of China's interprovincial migration that Fan and Chen did not find out in their research. A series of social-economic changes including rural transformation, balanced regional development, and labor market changes should be paid more attention to explore China's future interprovincial migration.  相似文献   

Relationship between surface pollen assemblages and vegetation in Luonan Basin,Eastern Qinling Mountains,Central China     

ZHANG Wenchao  LI Chunhai  LU Huayu  TIAN Xianhua  ZHANG Hongyan  LEI Fang  TANG Lingyu 《地理学报》2014,24(3):427-445

The catchment of South Luohe River in Central China is an important region for investigating modern pollen-environment relationship, because it is located in the transitional zone between south and north China, an environment which is sensitive to climate changes. In this study, 40 surface samples under ten vegetation types were collected to reveal the relationship between pollen assemblages and vegetation. The results show that the surface pollen assemblages reflect the vegetation quite well. In forest topsoils, the average of arboreal pollen content is greater than 40%, and the Selaginella sinensis spore is high. As to sparse forest grassland and shrub community, the average arboreal pollen is 13.2% and 16.6% respectively, and the shrub pollen is relatively higher than that of grassland samples. The grassland and farmland are characterized by low percentage of tree and shrub pollen (<10% and <1%), and high percentage of herbs (>80%). Pinus, Quercus and some other arboreal pollen can indicate the regional vegetation because of their dispersal ability. Quercus pollen is under-representative and so is Pinus. Artemisia pollen is significantly over-represented, has poor correlation with the plant coverage, and may reflect human disturbance. Gramineae can indicate plant quite well, but with low representation. High content of Chenopodiaceae probably suggests human impact. Predominant Selaginella sinensis can be used as an indicator of forest environment. Cluster analysis and principal components analysis of pollen assemblages can distinguish forest and non-forest vegetation well. The former method is better at separating pine and mixed forests, while the latter is more stable and could better differentiate farmland and other non-forest area. The first axis of PCA mainly reflects the humidity.  相似文献   

A new geographical language：A perspective of GIS     

HU Zui  TANG Guoan  LU Guonian 《地理学报》2014,24(3):560-576

Language plays a vital role in the communication, sharing and transmission of information among human beings. Geographical languages are essential for understanding, investigating, representing and propagating geo-spatial information. Geographical languages have developed and evolved gradually with improvements in science, technology and cognitive levels. Concerning the theoretical progress from geographical information ontology, epistemology and linguistic theory, this paper firstly puts forward the concept of a GIS language and discusses its basic characteristics according to changes in the structures, functions and characteristics of geographical languages. This GIS language can be regarded as a system of synthetic digital symbols. It is a comprehensive representation of geographical objects, phenomena and their spatial distributions and dynamic processes. This representation helps us generate a universal perception of geographical space using geographical scenarios or symbols with geometry, statuses, processes, spatio-temporal relationships, semantics and attributes. Furthermore, this paper states that the GIS language represents a new generation of geographical language due to its intrinsic characteristics, structures, functions and systematic content. Based on the aforementioned theoretical foundation, this paper illustrates the pivotal status and contributions of the GIS language from the perspective of geographical researchers. The language of GIS is a new geographical language designed for the current era, with features including spatio-temporal multi-dimension representation, interactive visualization, virtual geographical scenarios, multi-sensor perception and expedient broadcasting via the web. The GIS language is the highest-level geographical language developed to date, integrating semantic definitions, feature extraction, geographical dynamic representation and spatio-temporal factors and unifying the computation of geographical phenomena and objects. The GIS language possesses five important characteristics: abstraction, systematicness, strictness, precision and hierarchy. In summary, the GIS language provides a new means for people to recognize, understand and simulate entire geo-environments. Therefore, exploration of the GIS language’s functions in contemporary geographical developments is becoming increasingly important. Similarly, construction of the conceptual model and scientific systems of the GIS language will promote the development of the disciplines of geography and geographical information sciences. Therefore, this paper investigates the prospects of the GIS language from the perspectives of digital technology, geographical norms, geographical modeling and the disciplinary development of geography.  相似文献