矿区地表移动监测方法探讨     

胡海斌  郭新慧  阎跃观 《测绘与空间地理信息》2017,(10):21-23

针对因矿区地表地形复杂而导致的传统测量施测有困难的问题,探讨了三角高程测量对向观测法和RTK在此种情况下的适用性。结果表明:三角高程对向观测方法能满足四等水准测量限差要求,可以替代四等水准测量,适用于复杂矿区地表沉降变形监测的日常观测;RTK实时动态测量技术精度符合平面测量要求。  相似文献   

Elephants move faster in small fragments of low productivity in Amboseli ecosystems: Kenya     

Tawanda W. Gara  Tiejun Wang  Andrew K. Skidmore  Shadrack M. Ngene  Timothy Dube  Mbulisi Sibanda 《国际地球制图》2017,32(11):1243-1253

Understanding factors affecting the behaviour and movement patterns of the African elephant is important for wildlife conservation, especially in increasingly human-dominated savanna landscapes. Currently, knowledge on how landscape fragmentation and vegetation productivity affect elephant speed of movement remains poorly understood. In this study, we tested whether landscape fragmentation and vegetation productivity explains elephant speed of movement in the Amboseli ecosystem in Kenya. We used GPS collar data from five elephants to quantify elephant speed of movement for three seasons (wet, dry and transitional). We then used multiple regression to model the relationship between speed of movement and landscape fragmentation, as well as vegetation productivity for each season. Results of this study demonstrate that landscape fragmentation and vegetation productivity predicted elephant speed of movement poorly (R² < 0.4) when used as solitary covariates. However, a combination of the covariates significantly (p < 0.05) explained variance in elephant speed of movement with improved R² values of 0.69, 0.45, 0.47 for wet, transition and dry seasons, respectively.  相似文献   

Regional　characteristics　of　stress　field　in　the　southern　part　of　the　north－south　seismic　belt　in　China　and　its　relation　with　plate　movement     

徐纪人  尾池和夫 《地震学报(英文版)》1995,8(1):39-49

Ｒｅｇｉｏｎａｌｃｈａｒａｃｔｅｒｉｓｔｉｃｓｏｆｓｔｒｅｓｓｆｉｅｌｄｉｎｔｈｅｓｏｕｔｈｅｒｎｐａｒｔｏｆｔｈｅｎｏｒｔｈ－ｓｏｕｔｈｓｅｉｓｍｉｃｂｅｌｔｉｎＣｈｉｎａａｎｄｉｔｓｒｅｌａｔｉｏｎｗｉｔｈｐｌａｔｅ　ｍｏｖｅｍｅｎｔＪｉ－Ｒｅｎ...  相似文献   

Surface hydrology and soil movement in an arid karst: the Nullarbor Plain,Australia     

D. S. Gillieson  J. A. Cochrane  A. Murray 《Environmental Geology》1994,23(2):125-133

The Nullarbor Plain is the largest karst area in Australia (220,000 km²) and one of the largest in the world. Its climate is arid (Köppen BWk and BWh), and the surface relief is less than 10m. The landscape is divided into extensive closed karstic depressions separated by low rocky ridges, and the dominant vegetation is chenopod shrubland. The extent and severity of soil degradation has been assessed using remote sensing. GPS rectified images from 1972–1973, 1979, 1983, 1988, and 1991 have been compared for two sites on the Nullarbor. Over the 19 years the total extent of bare soil has reduced significantly, but some areas around water points have degraded and there is some disturbance due to fossorial wombats. Sheet-flow processes occur during intense rainfall events, which happen two or three times per decade. Runoff only occurs after the 10– or 50– year return frequency events, and at these times turbid water ponds in depressions and enters caves. Surface soil sorptivity and hydraulic conductivity differ markedly between ridges and depressions; the ridges are clearly zones of groundwater recharge, while ponding is evident in most depressions. Sorptivity is influenced by the extent and nature of ground cover and cryptogam crusts on the soil. The landscape has been divided into classes on the basis of vegetation type and percentage of foliage cover. In each class the activities of fallout radionuclides will be determined by high resolution spectroscopy. Preliminary results suggest that in undisturbed sites little sediment movement has occurred over the time scale of cesium-137 (the last 35 years) but that the landscape has been well sorted over a much longer time scale. Future work will investigate disturbed sites to estimate relative soil loss during the pastoral period.  相似文献   

长江河口底沙运动规律   总被引：11，自引：0，他引：11  

李九发  沈焕庭  徐海根 《海洋与湖沼》1995,26(2):138-145

于１９８１－１９８８年以浅地层剖面仪和回声测探仪取得沙波观测资料，运用这些资料以及河床表层沉积物和历年河口水文、地形资料，采用水文学、沉积学与泥水沙运动力学相结合的研究方法，分析长江河口底沙的运规律。结果表明：长江河口底沙运动非常频敏，一般有单颗粒滚动、跳跃，沙波及沙体推移等形式；在沙质床面上沙波发育良好，其形成、发展和消失和潮差落潮流速有一定的相关性，因受涨，落潮流改造，沙波难于得到充分发展；沙  相似文献   

风暴潮沿珠江河道上溯运动的数值模拟   总被引：4，自引：1，他引：4  

于斌  林少奕  王永信  史键辉  夏综万 《海洋学报》2001,23(4):17-24

采用动力学数值模式对风暴潮沿珠江河道上溯的个例进行了模拟,并就有关机制进行讨论.结果显示,风暴潮位是否沿珠江河道向北逐渐递增,和风暴强度有很大的关系,也和风暴登陆的路径有关;南海的热带气旋多数是西行的,这样就使本文研究的对象像是“过路”的风暴,伶仃洋的聚水面积不算大,加上蛛网般河网的分散作用,都使珠江一线的风暴增水很少超过2.5m.但即使这样规模的增水,也对河口平坦地区造成很大威胁.由于天文潮的耦合,以及浅水效应,风暴潮常有不同程度的变形.本文的模拟中,模式、参数和计算对象等早已选好,计算时只作了少许调整,就能得到较好的结果,说明模式是合理和可靠的.  相似文献   

Towards a process-based biogeography of reindeer—scaling space,time, and organizational levels of space use     

Roland Pape 《Norsk geografisk tidsskrift. Norwegian journal of geography》2016,70(4):230-246

Due to increasing anthropogenic habitat alteration, fragmentation, and loss, the analysis of how, when, and why animals select particular habitats has become a central issue in ecology and biogeography. Animals adapt to spatiotemporal variability in resources either by tracking these resources or by plasticity in behavior to cover their needs, leading to three important implications: movement, temporal variation, and individual trade-offs leading to intra-species variability, all of which are directly linked to the use of space by animals. Based on GPS-tracking of domesticated reindeer in southern Norway, the authors addressed these issues by analyzing movement patterns and space use simultaneously across different temporal and organizational scales. Emerging information about the space use by reindeer was found explicitly linked to scaling relations, reflecting the matter of scale as having important functional implications rather than solely being a technical question of extent and resolution. Adding movement into the analysis of space use further advances the necessary functional perspective on space use. The authors conclude that scaling not only space but also time and the organizational level, in combination with accounting for different behavioral states, brings biogeography closer to a process-based view, rather than solely pattern-based view.  相似文献   

基于高速摄像技术的推移质运动特征试验          下载免费PDF全文

王浩  袁强  孟震  龚家国 《水科学进展》2016,27(6):849-857

在明渠中开展不同水流条件下低强度均匀沙平衡输沙试验,基于灰度相减方法分析整个床面推移质运动特征,以探寻紊流结构与推移质运动之间的作用机理。结果表明:①受水槽横向方向水流强度分布特征影响,推移质运动概率从水槽中线到两侧壁逐渐变小,且基本呈对称分布;②在紊流相干结构作用下,推移质床面在紊流低速条带区形成凸槽,高速条带区形成凹槽,推移质运动概率沿水槽横向方向存在高低相间的带状分区;③随摩阻雷诺数增大,相邻两推移质运动高概率区域的间距值变化范围为0.13~0.24倍水槽宽度,其值随摩阻雷诺数增大而增大;④不同水流条件下,推移质运动高概率区域间距值约为水深的2倍,这与流向涡模型吻合,表明流向涡是诱导床面出现凹凸相间形态的重要因素。  相似文献   

江苏盐城大丰港西洋深槽冲淤变化特征     

张刚  杨轮凯  闫玉茹 《江苏地质》2016,40(4):683-689

西洋深槽是大丰港赖以生存的重要航道。在野外地质调查实测资料的基础上,结合以往的地形资料,从典型断面、等深线、区域等不同角度综合分析了近年来西洋深槽的地形冲淤变化特征,发现西洋深槽近期整体处于基本稳定状态。调查成果已转化应用,为大丰港区港航规划和可持续开发建设提供了基础数据。  相似文献   

基于数字剖面的河流阶地与新构造运动研究——以内蒙古西拉木伦河河流阶地为例     

周文孝  ;葛梦春  ;于庆文  ;李超岭  ;赵温霞  ;谢德凡 《中国区域地质》2008,(7):995-1001

野外调查发现在内蒙古东部西拉木伦河流域存在12级阶地序列。利用数字剖面野外系统对该河流阶地剖面的记录完成全程数字化采集,并进行数字剖面桌面系统厚度自动计算和剖面图、柱状图自动生成,发现该阶地序列中T7、T8、T9保存完好,而时代最为古老的T12 根据基座玄武岩形成于上新世—早更新世的年龄,其形成时代应为上新世—早更新世。通过计算新构造运动抬升速率,将其形成、演化过程划分为6个阶段。数据表明,自中新世以来,该地区新构造运动存在一定的周期性,在总体上新构造运动的强度逐渐趋于缓和。  相似文献