分布异构空间数据协同编辑关键技术研究

分布式环境下空间数据库的异构、多源、多平台特性,使不同系统之间难以实现协同处理。为实现分布异构空间数据的协同编辑,在研究网络要素服务(Web Feature Service,WFS)规范的基础上,对WFS规范中的锁定、编辑操作进行了改进,同时将发布订阅机制引入到基于WFS的网络空间数据编辑处理中,使其能够适应协同编辑的需求,并以此为基础提出了基于WFS的一致性控制机制、编辑机制和发布订阅机制,最后建立了相应的原型系统以验证其有效性。     

曲靖盆地生物气成藏条件及主控因素分析

曲靖盆地新近系茨营组第三段的晚期生物气藏是新近系沉积之后,喜山运动时期各种成藏条件有效的时空配置的结果.在讨论曲靖盆地构造和沉积演化的基础上,综合分析了生物气源、储集层和盖层、圈闭形成以及天然气输导等成藏条件,阐述了生物气晚期聚集成藏条件的时空匹配关系.指出自第四纪以来,生物气源岩持续高效的产气作用是生物气成藏的物质保障,气藏的形成是生物气连续的补充大于逸散动态平衡的产物;背斜构造、砂岩上倾尖灭和砂岩透镜体圈闭是该区主要的圈闭类型;断裂和不整合面是沟通生物气源岩到圈闭的垂向和侧向输导通道,茨营组的连通砂岩体是生物气近距离运移的输导层.蔡家冲组大套湖相暗色泥岩的生物产气效率、断裂的垂向输导能力和圈闭的保存条件及其在时空上的动态配置是生物气晚期成藏的主控因素.     

滇东南岩溶区地质灾害发育分布规律及其防治对策——以文山县为例

云南省文山县地质灾害类型多样,以滑坡、崩塌为主,不稳定斜坡、泥石流次之,岩溶塌陷零星分布.本文在结合实地调查的基础上,经过分析总结,详细阐述了文山县地质灾害的类型、数目和发育分布特征.最后,针对文山县的具体情况,提出了地质灾害防治的若干建议,为该县的防灾、减灾和促进区域经济社会可持续发展提供科学依据.     

基于MRMRF的多光谱纹理影像分割方法

提出了一种新的基于多分辨率马尔可夫场(multiresolution Markov random field, MRMRF)模型的小波域多光谱纹理影像分割方法.该方法采用可变的权重参数连接小波分解的多尺度特征场和标记场,通过直接映射,将上一尺度的分割结果作为下一尺度的初始结果,最细尺度上的分割结果作为算法的最终分割结果.实验表明,本文算法能够降低多光谱纹理图像分割的错误率.     

太湖秋季光学活性物质空间分布及其遥感估算模型研究

基于2004年秋季在太湖进行的一次大范围水体吸收系数、散射系数、辐照度比等生物光学特性及光学活性物质浓度的测定和计算,分析了秋季太湖光学活性物质浓度的空间分布特征以及水体生物光学特性,并在此基础上发展了内陆浅水湖泊非色素颗粒物、浮游植物色素和有色可溶性有机物(chromophoric dissolved organic matter,CDOM)的半分析模型.     

基于iPhone的WebGIS应用系统的研究与实现

在分析iPhone特性的基础上,结合工程实践,对面向iPhone基于WebGIS应用系统的实现进行研究,主要是对功能设计及布局、Ajax、canvas绘图等一系列关键技术进行研究并形成相关的应用技术和解决方案。该系统满足了大众对于在iPhone上实现WebGIS应用系统的需求,同时,该系统的实现对面向iPhone的Web应用有一定的借鉴作用。     

Automated Image Registration for Hydrologic Change Detection in the Lake-Rich Arctic

Multitemporal remote sensing provides a unique tool to track lake dynamics at the pan-Arctic scale but requires precise registration of thousands of satellite images. This is a challenging task owing to a dearth of stable features to be used as tie points [(TPs), i.e., control points] in the dynamic landscapes. This letter develops an automated method to precisely register images in the lake-rich Arctic. The core premise of the method is that the centers of lakes are generally stable even if their shorelines are not. The proposed procedures first extract lakes in multitemporal satellite images, derive lake centroids and match them between images, and then use the centroids of stable lakes as TPs for image registration. The results show that this approach can achieve subpixel registration accuracy, outcompeting the conventional manual methods in both efficiency and accuracy. The proposed method is fully automated and represents a feasible way to register images for lake change detection at the pan-Arctic scale.      

About the specification of erosion flux for soft stratified cohesive sediments

The present paper deals with the specification of bed erosion flux that accounts for the effects of sediment-induced stratification in the water column. Owing to difficulties in measuring the bed shear stress _b and the erosive shear strength _s, we suggest a series of methods that combine laboratory and numerical experiments. A simplified turbulent transport model that includes these effects helps to quantify _b and _s. Focusing on soft stratified beds, the present study considers erosion rate formulas of the form =_f exp {[T_b-T_s]} where is a model constant (=1 for Gularte's (1978) formula and =1/2 for Parchure's (1984) formula). First, the bed erosive strength profile _s(Z) is adjusted by forcing the turbulent transport model with measured erosion rates. Second, three procedures are suggested to determine the erosion rate formula coefficients _f and : a global procedure and two different layer-by-layer procedures. Each procedure is applied to an erosion experiment conducted in a rotating annular flume by Villaret and Paulic (1986). The use of the layer-by-layer procedure based on a least squares fitting technique provides a closer fit than the global procedure. The present study points out the complementarity of experimental and numerical approaches and also suggests possible improvements in laboratory test procedures.     

基于多源夜间灯光数据的成渝地区近15年城市扩展监测

针对成渝地区双城经济圈建设前期对成渝地区城市扩展监测的需求,本文研究了利用多源夜间灯光数据进行城市扩展监测的方法,并优化了多源夜间灯光数据整合过程中拟合样本选取的方法.本文利用2004—2018年成渝地区多源夜间灯光数据进行示范应用,围绕夜间灯光总量、夜光标准差椭圆和首位度等指标,开展了成渝地区近15年城市扩展监测.研究结果表明:整合后的多源夜间灯光数据一致性明显上升,可提高宏观尺度上长时间序列的城市扩展监测的可靠性;近15年,成渝地区"成都-重庆"双核发展趋势增强,重心逐渐东移,建成区夜间灯光总增长率超过154％.     

土钉墙与预应力锚杆联合支护技术

北京市深基坑工程中土钉墙支护技术应用比较广泛，对于边坡变形要求严格的基坑，采用土钉墙与预应力锚杆联合支护技术可有效控制变形，结合工程实例，介绍了该技术的设计思路及应用过程，说明了该技术的适用性，并就施工中遇到的问题进行分析，给出相应的处理措施。