基于三维激光扫描的滑坡变形监测与数据处理

地面三维激光扫描技术可以高精度、高密度、高速度地测量物体表面三维空间坐标,从而详细描述表面细部状况。它已经在静态形状测量中获得了成功的应用。目前,滑坡地表变形分析主要是采用GPS或全站仪测量的少量特征点来进行,缺乏整体变形资料。但滑坡变形体的诸多细节变化对正确的变形分析有着重要的作用,将该技术引入到滑坡变形监测与分析中,可充分利用滑坡体上的大量点自然地物作为监测点,来完整监测和分析其变形。作为一项新的研究内容,文章对此进行了相应的理论分析与实际测量,获得了初步满意的结果。     

考虑计算参数不确定性的边坡稳定分析

岩土体当中存在大量的不确定因素,给边坡的稳定性分析判断带来了困难。在分析了计算参数的不确定性是影响分析可靠性的主要原因的基础上,运用模糊集理论考虑计算参数的不确定性,提出了模糊参数的具体构造方法和边坡稳定的不确定性分析思路。该方法可以根据不同隶属度下的参数截集区间,计算出相应隶属度下的安全系数区间,并可由此得到边坡的可靠性指标和安全系数建议值。通过不同算例研究表明,使用此方法能充分考虑计算参数的不确定性,得到的安全系数更加科学可靠。     

多重网格区域分裂分布式计算

对分布式多重网格计算进行了研究.其顺序算法描述的是非递归形式, 算法并行化是基于区域分裂实现的.网状拓扑结构组织在多处理机上, 并行算法映射到多进程上, 在一定程度上显著提高并行化速度和并行化效率      

太原市地面沉降的计算与预测

为分析太原市地面沉降,对太原市区进行了地质模型概化,建立了太原市区大规模开采地下水引起地面沉降的数值计算模型,同时对研究区内的地面沉降进行了预测。分析结果表明,太原市地面沉降主要是由于集中开采深层承压含水层引起的。      

特长跨海大桥安全监测方法的研究

在特长跨海大桥施工定位与安全监测工作中经常遇到难以克服的困难,为此人们不得不借助于RTKGPS技术.当然,跨海大桥的安全监测问题单纯利用RTK GPS技术是远远不够的,因为跨海大桥安全监测的精度要求远远高于施工定位,不采取一定的技术措施很难实现对跨海大桥运营安全的有效监测.为了较好地解决特长跨海大桥的安全监测问题,笔者与科研小组结合实践提出了通过合理布设三维控制基准系统实施跨海大桥运营安全有效监测的想法,三维控制基准系统的构建应综合考虑投影问题、网形结构问题、施测方法问题,结合我国目前在建的几座跨海大桥论述了跨海大桥安全监测三维控制基准系统构建的基本设计思路.     

基于ObjectArx.net的面状符号自动绘制的实现方法

面状符号的绘制是数字化测图软件必不可少的功能,也是基于AutoCAD平台的数字化测图软件开发的重要组成部分.针对AutoCAD用户在面状符号绘制方面存在的问题,通过对传统CAD面状区域填充算法的研究,提出一种用自定义块对象作填充图案并结合传统的图案填充法和插入法来实现面状符号自动绘制的简易方法,并运用C#+ObjectArx.net在AutoCAD 2007中实现了该算法.     

GAT陀螺全站仪在井下控制测量中的应用

为了减小测角误差对导线点位误差的影响,提高井下控制网的精度,运用GAT陀螺全站仪进行井上、井下陀螺定向观测和平差处理,实现了井下导线的精确定位。通过实例分析,GAT陀螺全站仪在井下导线测量中极大地提高了导线的精度和可靠性。     

青岛海区近岸工程波高的数值计算——青岛小麦岛污水处理厂工程应用

根据青岛小麦岛污水处理厂的工程实际,采用波数矢量无旋和能量守恒关系对近岸波高进行数值计算,获得了该地区附近的近岸波高,为工程设计提供了可靠的设计依据。     

Evaluation of the carbon sequestration of Zhalong Wetland under climate change

Wetland ecosystems are crucial to the global carbon cycle.In this study,the Zhalong Wetland was investigated.Based on remote sensing and meteorological observation data from 1975–2018 and the downscaled fifth phase of the coupled model intercomparison project (CMIP5) climate projection dataset from 1961–2100,the parameters of a net primary productivity (NPP) climatic potential productivity model were adjusted,and the simulation ability of the CMIP5 coupled models was evaluated.On this basis,we analysed the spatial and temporal variations of land cover types and landscape transformation processes in the Zhalong Nature Reserve over the past 44 years.We also evaluated the influence of climate change on the NPP of the vegetation,microbial heterotrophic respiration (Rh),and net ecosystem productivity (NEP) of the Zhalong Wetland and predicted the carbon sequestration potential of the Zhalong Wetland from 2019–2029 under the representative concentration pathways (RCP) 4.5 and RCP 8.5 scenarios.Our results indicate the following:(1) Herbaceous bog was the primary land cover type of the Zhalong Nature Reserve,occupying an average area of 1168.02±224.05 km~2,equivalent to 51.84%of the total reserve area.(2)Since 1975,the Zhalong Nature Reserve has undergone a dry–wet–dry transformation process.Excluding several wet periods during the mid-1980s to early 1990s,the reserve has remained a dry habitat,with particularly severe conditions from 2000 onwards.(3) The 1975–2018 mean NPP,Rh,and NEP values of the Zhalong Wetland were 500.21±52.76,337.59±10.80,and 162.62±45.56 g C·m~(-2)·a~(-1),respectively,and an evaluation of the carbon balance indicated that the reserve served as a carbon sink.(4) From 1975–2018,NPP showed a significant linear increase,Rh showed a highly significant linear increase,while the increase in the carbon absorption rate was smaller than the increase in the carbon release rate.(5) Variations in NPP and NEP were precipitation-driven,with the correlations of NPP and NEP with annual precipitation and summer precipitation being highly significantly positive(P0.001);variations in Rh were temperature-driven,with the correlations of Rh with the average annual,summer,and autumn temperatures being highly significantly positive (P0.001).The interaction of precipitation and temperature enhances the impact on NPP,Rh and NEP.(6) Under the RCP 4.5 and RCP 8.5 scenarios,the predicted carbon sequestration by the Zhalong Wetland from 2019–2029 was 2.421 (±0.225)×10~(11) g C·a~(-1) and 2.407 (±0.382)×10~(11) g C·a~(-1),respectively,which were both lower than the mean carbon sequestration during the last 44 years (2.467 (±0.950)×10~(11) g C·a~(-1)).Future climate change may negatively contribute to the carbon sequestration potential of the Zhalong Wetland.The results of the present study are significant for enhancing the abilities of integrated eco-meteorological monitoring,evaluation,and early warning systems for wetlands.     

INCORPORATING RADIATION INPUTS INTO THE SNOWMELT RUNOFF MODEL

Process-based, distributed-area snowmelt runoff models operating at small scales are essential to understand subtle effects of climate change, but require data not commonly available. Temperature index models operating over large areas provide realistic simulations of basin runoff with operationally available data, but lack rigorous physically based algorithms. A compromise between the two types of models is required to provide realistic evaluations of basin response to environmental changes in cold regions. One adaptation that is uniformly required for snowmelt models is the use of remotely sensed data, either as input or in model validation. At a minimum, snowmelt forecasting models need to incorporate snowcover extent information, which is currently obtained operationally. As more remote sensing capabilities come on line, models should accept upgraded information on snow water equivalent; additional remotely sensed information on landcover, frozen soil, soil moisture, cloudiness and albedo would also be useful. Adaptations to the semi-distributed snowmelt runoff model (SRM) are underway to make it more physically based for use in large area studies. A net radiation index has been added to the model, which formerly used only a temperature (degree–day) index to melt snow from a basin's elevation zones. The addition of radiation to the SRM allows the basin to be subdivided into hydrological response units by general aspect (orientation) as well as elevation. Testing of the new radiation-based SRM with measured radiation from a small research basin is the first step towards large scale simulations. Results from the W-3 research basin in Vermont, USA are promising. In the radiation version, the factor that multiplies the degree–day index is estimated independently of model output and is held constant throughout the season, in contrast with the degree–day version, where the corresponding factor is allowed to increase throughout the season. Without calibrating or optimizing on this important parameter, the goodness-of-fit measure R² is improved in two out of six test years when the radiation version of the SRM is used in place of the degree–day version in melt season simulations. When the accumulation of error is eliminated with periodic updating of streamflow, more significant improvement is noted with radiation included.