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81.
82.
Qiao Hu Zhenghong Tang Lei Zhang Yuanyuan Xu Xiaolin Wu Ligang Zhang 《Natural Hazards》2018,92(2):783-804
Climate change brings uncertain risks of climate-related natural hazards. The US Federal Emergency Management Agency (FEMA in Climate change: long-term trends and their implications for emergency management, 2011. https://www.fema.gov/pdf/about/programs/oppa/climate_change_paper.pdf) has issued a policy directive to integrate climate change adaptation actions into hazard mitigation programs, policies, and plans. However, to date there has been no comprehensive empirical study to examine the extent to which climate change issues are integrated into state hazard mitigation plans (SHMPs). This study develops 18 indicators to examine the extent of climate change considerations in the 50 SHMPs. The results demonstrate that these SHMPs treat climate change issues in an uneven fashion, with large variations present among the 50 states. The overall plan quality for climate change considerations was sustained at an intermediate level with regard to climate change-related awareness, analysis, and actions. The findings confirm that climate change concepts and historic extreme events have been well recognized by the majority of SHMPs. Even though they are not specific to climate change, mitigation and adaptation strategies that can help reduce climate change risks have been adopted in these plans. However, the plans still lack a detailed assessment of climate change and more incentives for collaboration strategies beyond working with emergency management agencies. 相似文献
83.
The aim of this paper is to propose a location model of earthquake emergency service depot on the basis of hybrid multi-attribute decision-making method. The advantage of the proposed method is that practical mixed uncertainty of location decision information is considered, and the corresponding factors that affect the location of transfer stations are contained. To solve the location problem, a hybrid multi-attribute decision procedure without information transformation is developed. Besides, a novel weighting method and aggregation process is given. Finally, a numerical example is provided to show the feasibility and validity of the proposed method. 相似文献
84.
A new multipath mitigation method based on adaptive thresholding wavelet denoising and double reference shift strategy 总被引:1,自引:0,他引:1
Multipath disturbance is one of the major error sources in high-accuracy positioning for global navigation satellite system (GNSS). Although various methods based on software and hardware strategies have been developed to mitigate this error, they are still limited by different kinds of factors and the effect is not ideal. After analyzing the existing methods, a new single-difference sidereal filtering method, based on adaptive thresholding wavelet denoising and double reference shift strategy (ATDR), is proposed to mitigate multipath effects for static short-baseline GNSS applications. The key idea of the proposed method is the use of both the adaptive thresholding wavelet denoising to extract an accurate multipath correction model from the reference Day and the double reference shift strategy to mitigate multipath for subsequent Day 2 more accurately and efficiently. By applying the introduced adaptive thresholding method, the average improvement rate of the RMS values of the single-difference residuals can reach about 15.82% compared with the constant thresholding method. Moreover, after applying the proposed ATDR method, the 3D positioning precision is improved by about 37.73% for the single epoch mode with 30 s data sampling rate and about 31.22% for the continuous mode with 1 s high sampling rate compared with the original results. Even compared with the constant thresholding single orbital reference (CTSR) method, the improvement percentage is about 33.94% in single epoch mode and about 25.40% in continuous mode for 3D positioning precision, respectively. In conclusion, the results of the two experiments indicate that the proposed ATDR method performs much better than the CTSR method in mitigating multipath for different sampling rates and different processing modes in the measurement domain for GNSS static short-baseline postprocessing applications. 相似文献
85.
Natural Hazards - In the freeze–thaw zone of the eastern Sichuan–Tibet Mountains, the phases of water in cracks show strong seasonal variations, which significantly affect the stability... 相似文献
86.
Natural Hazards - Frequent occurrences of drought stress caused by dry weather create severe destroy in apple yield and quality in North China. Although appropriate drought stress is beneficial to... 相似文献
87.
Landslides - Landslide-induced tsunamis are common natural hazards that potentially affect the safety and stability of waterfront structures. A numerical tank was constructed using FLOW-3D to... 相似文献
88.
We present an aerosol injection technique (AIT) to accelerate the consolidation of soft soils for ground improvement. We employ high-pressure aerosol injections at different depths to enhance the drainage in soft soils for faster consolidation. The technique is briefly described. A well-instrumented field test is carried out to demonstrate its performance. Compared to the traditional methods, our approach gives rise to faster dissipation of excess pore pressure and larger ground settlement. This method is particularly attractive for the improvement in soft ground in medium depths.
相似文献89.
Ping Wu Yang Guo Dayong Zhu Weiliang Jin Zhenhua Zhang Rongzhu Liang 《Marine Georesources & Geotechnology》2020,38(5):518-526
AbstractThis study developed prestressed high-strength concrete (PHC) piles reinforced with high-strength materials (glass fiber-reinforced polymer (GFRP) bars) for flexural performance enhancement. Flexural strengths and behaviors of PHC piles reinforced with hybrid GFRP and steel bars were experimentally investigated, respectively. Large-scale specimens with total lengths of 12,000?mm and diameters of 600?mm were constructed and tested under bending, accompanied by evaluation of effects of non-prestressed reinforcement type and longitudinal reinforcement ratio. J-factors were calculated to evaluate deformability of all the specimens. PHC piles reinforced with GFRP bars were demonstrated to have much higher flexural capacity than those reinforced with steel bars. Moreover, strains at the midspans of cross sections of all the specimens basically conformed to the assumption of plane section. Failure of PHC piles reinforced with GFRP bars was attributable to gradual concrete crushing, while that of PHC piles reinforced with steel bars resulted from steel yielding. Results of this study were expected to provide theoretical basis for wide engineering applications of PHC piles reinforced with hybrid GFRP bars and steel bars in marine structures. 相似文献
90.
Feiyu Liu Wenqing Wu Jun Wang Jun Hai Yuanqiang Cai 《Marine Georesources & Geotechnology》2020,38(2):164-173
AbstractTo achieve the rapid dewatering of dredged sludge, the flocculation–vacuum-preloading method was tested indoors. In this study, the optimal mixing ratio of six flocculants was determined through the settling column test, and then the proposed method was tested. The water drainage and settlement were monitored during the test, while the soil moisture content and shear strength were measured after the test. The results show that all the flocculants had an optimal mixing ratio, and the addition of 0.8% FeCl3 or 0.08% anionic polyacrylamide (APAM) in the sludge can better accelerate solid–liquid separation of the sludge. After the test, the water content in the sludge decreased from 140% to 60%. Compared with general vacuum preloading, the use of the proposed method increased the water drainage by 46.5% and 56.8% and decreased the soil volumes by 60.5% and 82.4% for FeCl3 and APAM, respectively. Moreover, the corresponding shear strength was increased from 10 to 14 and 17?kPa. In addition, the use of APAM increased the solidification rate of heavy metals in the sludge to more than 80%, effectively inhibiting the migration of heavy metals. 相似文献