基于小型无人机航拍影像的地表房屋建筑提取算法对比——以新疆阿图什市琼哈拉峻村为例

选取新疆阿图什市下辖的琼哈拉峻村为研究区,将小型旋翼无人机拍摄的图像作为数据源,分别采用面向对象以及面向像元2种影像分析方法对研究区的房屋建筑进行提取,并对2种算法的提取结果进行对比,分析了各自的优势。结果表明:面向对象方法可以有效地去除椒盐噪声对分类带来的影响,保证房屋形态的完整性,但影响内部相似的光谱、纹理信息若对应多种物体则会导致影像对象的错分。在面向像元的提取方法中加入了改进的数学形态学算法,可有效的抑制椒盐噪声,保持建筑物边缘的连续性与完整性,较好地解决了面向对象方法中部分农田与房屋出现错分的问题。     

significance of high-resolution loess stratification based on grain size and magnetic susceptibility analysis to paleo-earthquake study: a case study of dongyugou loess section,at hongtong,shanxi province

As an important technology to paleoseismologic research, trenching has been used to identify paleo-earthquakes recorded in strata, combined with dating technology. However, there have been some bigger uncertainties and limitations. For instance, subtle strata in loess sediment cannot be interpreted only by naked-eye, which seriously affects identifying paleo-earthquake horizon and time. Therefore, how to improve the accuracy and reduce the uncertainty of paleo-earthquake identification is the important problem we are currently facing. Dongyugou loess section, located in the northeastern corner of Linfen Basin, Shanxi Province, cuts across the Huoshan piedmont fault. The section exposes not only the well-developed loess sequence, but also several obvious faulting events. Thus, this loess section is a better site to make a high resolution study to improve the accuracy and reduce the uncertainty of paleo-earthquake identification. Based on the high-resolution grain size and magnetic susceptibility analysis, and associated with visual interpretation by naked-eye, we made a high-resolution stratification of Dongyugou loess section, including high-resolution thickness of each stratum and its upper and bottom boundaries. Based on the high-resolution stratification and their comparison between two fault walls, we identified three earthquake events, which occurred after formation of u5-7, u4 and u2, corresponding to their stratification depth of 7.1m, 4.7m and 2.9m in hanging wall. Based on results of OSL dating and average sedimentation rate of hanging wall, we estimated that the three events occurred around 45.8ka(between (48.1±1.5)～(43.2±2.5)ka), 32.8ka(between (35.0±2.4)～(30.6±1.3)ka) and 23.3ka(between (26.4±0.8)～(20.9±0.7)ka). According to the thickness difference of three loess-paleosol sedimentary cycles between two fault walls, we calculated the coseismic vertical displacements of the three events as 0.5m, 0.4 and 1.3m, respectively. Compared with other segments of the Huoshan piedmont fault zone, we found the southernmost segment is the weakest, with longer recurrence interval of about 11ka and lower vertical slip rate of 0.048mm/a. The high-accuracy grain size and magnetic susceptibility analysis offers an effective method for reducing the uncertainties of the paleo-earthquake research in loess area.     

SESAM锁模激光器在卫星激光测距领域应用研究

本文在分析SESAM(Semiconductor Saturable Absorber Mirrors)锁模激光器原理及技术特点、描述其工作流程的基础上,展示了SESAM锁模激光器用于卫星激光测距的实测结果,通过对卫星激光测距数据数量及质量分析,得出了SESAM锁模激光器以窄脉冲宽度、高能量密度、输出稳定等优势首次在国内应用于卫星激光测距系统后,使系统整体性能得到明显提升的结论。     

特殊情况下深基坑围护测斜及变形浅析

结合工程实例具体阐述当测斜管不能正常使用情况下运用全站仪代替测斜仪进行深基坑围护结构的倾斜测量,同时运用岩土工程相关知识对所得监测数据表现的变形及突变原因作了深入分析,获得了预期的安全监测成果,确保了深基坑工程的顺利实施。为今后类似情况的处理提供借鉴。     

松辽盆地开鲁坳陷钱家店地区姚家组砂岩地球化学特征及物源和构造背景分析

为了开展钱家店铀矿床砂岩型铀矿的进一步找矿工作,对采集到的上白垩统姚家组19件砂岩样品进行了主、微量和稀土元素分析,并结合前人成果,对姚家组的沉积物源及源岩构造背景进行了探讨。结果表明,姚家组砂岩主要为长石砂岩,矿物成分主要为石英、钾长石和斜长石等;其轻重稀土比为6.96~14.66,均值为10.17;LaN/YbN为7.58~20.95,均值为11.74,说明轻稀土元素相对重稀土元素明显富集,分馏明显。稀土元素配分模式曲线高度一致,也表明姚家组砂岩具有同源性;其ICV值为0.86~2.78,平均值1.34,大部分大于1,表现为未成熟的性质,为初次旋回的沉积物;修正后的CIA均值62.5,暗示源岩经历中等化学风化作用;砂岩碎屑为近源的第一次旋回沉积物,受沉积分选和再循环作用影响不大;姚家组源岩以火山弧物质和大陆上地壳长英质物质为主,源岩主要形成于大陆边缘和大陆岛弧环境;开鲁坳陷形成于早白垩世随着古太平洋板块向欧亚板块俯冲速度的减小而在东北地区出现的北西-南东向拉张构造环境中,并接受盆地西部大兴安岭南段海西期和燕山期岩浆岩、火山岩沉积。     

中小区域短临泥石流滚动预报系统的研制

将GIS技术与中小区域泥石流短临预报相结合,建立了基于多普勒天气雷达探测技术的中小区域短临泥石流滚动预报业务系统,实现了凉山州泥石流无缝隙的滚动预报,预报间隔为1 h,预报时效为3 h。模拟预报结果表明:系统可应用于预报业务。     

Review on Montane Forest Eco-hydrology in Arid Area

Since the forest eco-hydrology of arid area shows a well sensitivity of the global climate change, the relationship between forest and water and the hydrological function has attracted the attention of academic communites and management departments. This paper expounds the research progress in arid mountain forest eco-hydrology, and analyses the formation and stable mechanism of forest patch pattern, the relationship between forest and water yield and the response of forest eco-hydrology to climate change from three aspects: Forest spatial pattern, hydrological process and its response to climate change. In addition, combined with the current research progress, the research emphases in the future are put forward: Strengthening the research on the coupling of vegetation pattern and hydrological process; solving the scale problem by using remote sensing technique and model; enhancing the understanding towards the hydrological function of forest; determining the suitable forest scale which can balance the relationship of ecology and hydrological effect.     

海南东南部韧性剪切变形带锆石U-Pb年代学特征及其地质意义

海南东南部韧性剪切变形带断续出露于芒三水库—吊罗山林场—兴隆—线,走向北东,岩石有构造片麻岩和糜棱岩化花岗岩,主要矿物组成为长石、石英、黑云母.岩石发育“S-C”组构、“δ”型旋转碎斑系、云母鱼等变形组构,指示具有右行剪切活动的特点.根据矿物组成及变形特征,认为其变形环境相当于低角闪岩相,属于沿剪切带侵位并发生同步变形的产物.在芒三水库、吊罗山林场两地测得岩石锆石激光ICP-MS法年龄分别为284.3±1.3 Ma、265.9±1.3 Ma,属二叠纪形成.剪切变形带的发现及其年代学的厘定,对深入研究海南岛构造-岩浆作用具有重要的地质意义.     

SL3-1雨量传感器在应用中存在问题及解决方法

介绍自动气象雨量站SL3-1雨量传感器在使用中出现故障现象及改进方法,对台站维护起着参考作用。     

基于图分割的可变比例尺地图分幅回溯算法

总结了地图分幅需遵循的原则,并针对地图集中可变比例尺的分幅,将其定义为基于约束条件的图分割问题,用最小生成树(minimum spanning tree,MST)将制图区域关联起来,基于回溯算法对MST裁剪实现地图集的分幅。实验结果表明,所提出的方法能较好顾及地图集分幅的相关原则,满足地图集制作的要求。同时,利用该方法设计的地图集分幅工具已成功应用于《武汉市汉阳地区地名图集》等的制作,有效提高了地图设计人员的工作效率。