滑坡动态综合治理各阶段的监测信息反馈     

尹光志  张卫中  康钦容 《岩土力学》2006,27(Z1):661-664

滑坡监测是滑坡综合治理中一项必不可少的环节,不同阶段发挥着重要的作用。借助监测,能了解滑坡的实际状况,可以判断其稳定性及所处变形阶段,为滑坡治理初步决策提供科学依据。在治理过程中,实时监测反馈又为设计方案的修改和补充以及现场信息化施工提供可靠资料,为工程质量提供保障,施工结束后的监测数据又视为工程治理效果的直接指示 器。以某古滑坡路段高边坡综合治理中各阶段的监测为例,介绍了不同阶段的监测方法以及所获得的数据信息在滑坡治理中的作用。  相似文献   

High resolution WRF climatic simulations for the Iberian Peninsula: Model validation     

《Physics and Chemistry of the Earth》2016

A high resolution atmospheric modelling study was done for a 20-year recent historical period. The dynamic downscaling approach adopted used the Max Planck Institute Earth System Model (MPI-ESM) to drive the WRF running in climate mode. Three online nested domains were used covering part of the North Atlantic and Europe, with a resolution 81 km, and reaching 9 km in the innermost domain which covers the Iberian Peninsula.This paper presents the validation of the WRF configuration, which is based on historic simulations between 1986 and 2005 and observational datasets of near surface temperature and precipitation for the same period. The validation was done in terms of comparison of probability distributions between model results and observations, as daily climatologies, spatially averaged inside subdomains obtained with cluster analysis of the observations, for each of the four seasons. In addition, Taylor diagrams are presented for each of the seasons and subdomains. This validation approach was repeated with the results of a new WRF simulation with the same parameterisations but forced by the ERA-Interim reanalysis. The capacity of the MPI-ESM driven WRF configuration to compare with observations and in a manner similar to the ERA-Interim driven WRF, ensures the capacity of the configuration for climate and climate change studies.Considering the difficulty to simulate extremes in long term simulations, the results showed a comfortable comparison of both models (forced by climate model and reanalysis results) with observations. This provides us confidence on the continuity of using the MPI-ESM driven WRF configuration for climate studies.  相似文献   

不同植被盖度沙质草地生长季土壤水分动态   总被引：1，自引：1，他引：1  

王明明  刘新平  李玉霖  车力木格  罗永清  孙珊珊  魏静 《中国沙漠》2019,39(5):54-61

水分是干旱半干旱沙地生态系统最大的限制因子，研究植被盖度和土壤水分之间的关系有助于沙地生态恢复和保护。基于生长季科尔沁沙质草地不同植被盖度下土壤水分动态和降水的观测试验，分析了沙质草地植被盖度和土壤水分的耦合关系。结果表明：在土壤剖面上土壤水分存在明显的分层结构，依次为水分剧变层（0~40 cm）、缓变层（40~100 cm）和稳定层（100~180 cm）；植被盖度对土壤水分有很大影响，不同植被盖度下土壤含水量存在显著差异，土壤水分与盖度之间呈倒“V”型关系，土壤水分状况在28%的盖度下最优；不同的植被盖度下土壤水分对降水的响应也存在差异，在13%盖度下响应最敏感，28%和46%的盖度下响应微弱，后二者的土壤水分也相对稳定。在沙地生态恢复建设过程中合理的植被盖度配置可提高降水利用效率，并能使土壤水分和植被达到一种良好的平衡状态，从而有利于生态系统的稳定。  相似文献   

低轨卫星初始状态误差对反演地球重力场的影响     

张兴福  沈云中 《测绘科学》2009,34(3)

基于动力学法反演地球重力场的基本理论,研究了卫星初始状态向量误差对应用低轨卫星精密轨道数据反演地球重力场的影响。在仅考虑低轨卫星初始状态误差的情况下进行了模拟计算,结果表明:在利用低轨卫星精密轨道数据反演地球重力场时,卫星初始状态向量误差需要重新进行估计;在目前的轨道精度水平下,若不顾及误差方程二次项的影响,反演弧长不宜过长;卫星初始状态速度误差(约1.5mm/s)的影响要大于位置误差(约10 cm)的影响。  相似文献   

新疆天山北坡一次区域性暴雪形成机制及水汽输送特征分析     

万瑜 《沙漠与绿洲气象(新疆气象)》2024,18(4):9-16

利用高空、地面常规观测资料、NCEP/NCAR再分析资料，诊断分析了2017年2月新疆天山北坡一次区域性暴雪过程的特征及成因，结合GDAS再分析资料并采用HYSPLIT模式，模拟追踪水汽源地、主要水汽输送通道及其对水汽输送的贡献。结果表明：此次天山北坡暴雪是在典型后倾结构的高低空系统配置下产生的，中、高纬地区短波槽在东移过程中同位相叠加，为暴雪长时间维持提供了稳定的天气尺度背景；暴雪发生时位势不稳定性加强，中低层持续冷垫抬升是主要的动力机制，较强垂直风切变是降雪强度较大的重要原因，高低空急流耦合激发中尺度垂直上升支和次级环流圈，地形作用对暴雪有增幅作用；暴雪主要水汽源地位于阿拉伯半岛西侧的红海和伊朗高原西南侧的波斯湾至阿拉伯海北部一带，水汽通道主要集中在500～850 hPa，水汽辐合区位于700～850 hPa，中高层有偏西气流、中层有西南气流、低层有西北急流将水汽接力输送至暴雪区；利用HYSPLIT模式模拟发现，暴雪期间，西、东、南边界水汽输入均起重要作用，主要水汽输送通道分别为偏西路径、偏西南路径、局地水汽路径，1500 m高度的追踪，三者贡献率大致相当，3000 m高度，局地水汽和偏西路径水汽贡献率更大。  相似文献   

Preliminary Studies on Predicting the Tropical Indian Ocean Sea Surface Temperature through Combined Statistical Methods and Dynamic ENSO Prediction          下载免费PDF全文

WANG Li-Wei  ZHENG Fei  ZHU Jiang 《大气和海洋科学快报》2013,6(1):52-59

The sea surface temperature(SST) in the Indian Ocean affects the regional climate over the Asian continent mostly through a modulation of the monsoon system.It is still difficult to provide an a priori indication of the seasonal variability over the Indian Ocean.It is widely recognized that the warm and cold events of SST over the tropical Indian Ocean are strongly linked to those of the equatorial eastern Pacific.In this study,a statistical prediction model has been developed to predict the monthly SST over the tropical Indian Ocean.This model is a linear regression model based on the lag relationship between the SST over the tropical Indian Ocean and the Ni o3.4(5°S-5°N,170°W-120°W) SST Index.The predictor(i.e.,Ni o3.4 SST Index) has been operationally predicted by a large size ensemble El Ni o and the Southern Oscillation(ENSO) forecast system with coupled data assimilation(Leefs_CDA),which achieves a high predictive skill of up to a 24-month lead time for the equatorial eastern Pacific SST.As a result,the prediction skill of the present statistical model over the tropical Indian Ocean is better than that of persistence prediction for January 1982 through December 2009.  相似文献   

Improving Statistical Downscaling of General Circulation Models     

Matthew Lee Titus  Jinyu Sheng  Richard J. Greatbatch  Ian Folkins 《大气与海洋》2013,51(2):213-225

  相似文献   

Recent Near-surface Temperature Trends in the Antarctic Peninsula from Observed,Reanalysis and Regional Climate Model Data     

Deniz BOZKURT  David HBROMWICH  Jorge CARRASCO  Keith MHINES  Juan Carlos MAUREIRA  and Roberto RONDANELLI 《大气科学进展》2020,37(5):477-493

This study investigates the recent near-surface temperature trends over the Antarctic Peninsula.We make use of available surface observations,ECMWF’s ERA5 and its predecessor ERA-Interim,as well as numerical simulations,allowing us to contrast different data sources.We use hindcast simulations performed with Polar-WRF over the Antarctic Peninsula on a nested domain configuration at 45 km(PWRF-45)and 15 km(PWRF-15)spatial resolutions for the period 1991?2015.In addition,we include hindcast simulations of KNMI-RACMO21P obtained from the CORDEX-Antarctica domain(~50 km)for further comparisons.Results show that there is a marked windward warming trend except during summer.This windward warming trend is particularly notable in the autumn season and likely to be associated with the recent deepening of the Amundsen/Bellingshausen Sea low and warm advection towards the Antarctic Peninsula.On the other hand,an overall summer cooling is characterized by the strengthening of the Weddell Sea low as well as an anticyclonic trend over the Amundsen Sea accompanied by northward winds.The persistent cooling trend observed at the Larsen Ice Shelf station is not captured by ERA-Interim,whereas hindcast simulations indicate that there is a clear pattern of windward warming and leeward cooling.Furthermore,larger temporal correlations and lower differences exhibited by PWRF-15 illustrate the existence of the added value in the higher spatial resolution simulation.  相似文献   

基于通量均衡基准的地壳垂直形变场逼近的Fourier分析法   总被引：1，自引：1，他引：0  

赵超英  张勤  范一中 《测绘科学》2005,30(6):25-27

本文根据地壳运动的全球通量均衡假说建立了地壳垂直形变场的分析模型,分析了以往作者所研究的球谐函数和球冠谐函数模型的优缺点,着重推导了在密切平面坐标系下该模型的Fourier级数解,该模型一方面可以简单地应用于地壳垂直形变场的逼近,另一方面为采用谱分析法提取地壳垂直形变场信息提供了理论依据。  相似文献   

A new methodology for building local climate change scenarios: A case study of monthly temperature projections for Mexico City     

《Atmósfera》2014,27(4):429-449

This paper proposes a new methodology for generating climate change scenarios at the local scale based on multivariate time series models and restricted forecasting techniques. This methodology offers considerable advantages over the current statistical downscaling techniques such as: (i) it provides a better representation of climate at the local scale; (ii) it avoids the occurrence of spurious relationships between the large and local scale variables; (iii) it offers a more appropriate representation of variability in the downscaled scenarios; and (iv) it allows for compatibility assessment and combination of the information contained in both observed and simulated climate variables. Furthermore, this methodology is useful for integrating scenarios of local scale factors that affect local climate. As such, the convenience of different public policies regarding, for example, land use change or atmospheric pollution control can be evaluated in terms of their effects for amplifying or reducing climate change impacts.  相似文献