预应力锚索在316国道滑坡整治中的使用及存在问题初探

通过闽北滑坡整治工程监理实践 ,分析预应力锚索施工中存在的问题 ,提出相应的对策 ,探讨以寻求一种更科学的方法来保证预应力锚索工程施工的质量和效益     

Vegetation recovery monitoring and assessment at landslides caused by earthquake in Central Taiwan

Massive landslides, caused by the catastrophic Chi-Chi earthquake in 1999, occurred at the Jou-Jou Mountain area in the Wu-Chi basin, Taiwan. Multi-temporal satellite images and digital elevation models coupled with GIS were used to process the vegetation index analysis for identifying landslide sites and calculating the vegetation recovery rate (VRR). Topographic information for these areas was extracted. Eight hundred twenty-nine hectares of landslide area was extracted from multi-date NDVI images by combining the image differencing method with the change detection threshold. Over 2 years of monitoring and assessing, the vegetation recovery rate reached 58.93% original vegetation regeneration in the landslide areas. Soil moisture is one of the most important environmental factors for vegetation recovery in the landslide sites. The analyzed results provide very useful information for decision making and policy planning in the landslide area.     

地震诱发滑坡的机理研究

在阅读大量相关文献的基础上,归纳了国内外地震诱发滑坡的机理研究现状,分析了毛彦龙等学者提出的累进破坏效应结论,并基于此探讨了地震诱发滑坡的机理研究的发展趋势。     

GPS监测山体滑坡方法的研究

采用GPS相对静态定位技术监测山体滑坡,从滑坡监测网的基准点、监测点设计和观测出发,提出了利用高精度全站仪提供的尺度与方位基准来获得相对稳定不变的基准点坐标数据方法;在监测数据处理中对于不同监测周期的网形、起算点选取等对解算结果产生的影响进行了试验研究,提出适宜的解决方法,为今后的山体滑坡GPS监测提供理论和技术依据。     

瑞丽市滑坡灾害调查

对云南瑞丽市6个乡镇地质灾害进行调查。结果显示:该区滑坡总数为51个,形态以舌形、半圆形为主;滑坡规模以小型居多,占82.35%;滑坡主要发生在岩层倾向与坡向大致斜交的斜向坡部位。同时,对滑坡的危害程度、形成条件、稳定性与发展趋势进行了全面分析。     

水城"7·23"特大山体滑坡气象保障服务案例与启示

2019年7月23日,贵州省六盘水市水城县发生一起特大山体滑坡灾害。以此次特大山体滑坡前期精密监测、精准预报预警服务和中后期精细应急气象保障服务为案例,梳理了六盘水市县两级气象部门在此次突发公共事件服务过程中充分发挥气象防灾减灾第一道防线作用的经验和做法,总结了存在的不足,并思考下一步工作的方向。     

云南瑞丽市灾种统计的防治意义

统计了云南省瑞丽市灾害的类型及6个乡镇灾害的分布情况,同时分析了灾种发生的坡度、岩性组合以及诱发因素的种类。结果表明,云南瑞丽市地质灾害类型有滑坡、崩塌、泥石流和不稳定斜坡。滑坡多发生在第四系成因的含砾粉土中;崩塌多发生在泥岩、片麻岩构成且地质构造发育的陡坎、陡崖部位;降雨是地质灾害最主要的诱发因素,不合理的人类工程活动加剧了地质灾害发生频率;地震也是诱发地质灾害产生的原因之一。     

Multi-temporal modeling of road-induced overland flow alterations in a terraced landscape characterized by shallow landslides

The presence of roads in high steep agricultural systems is often linked with landslides occurrence. This research aims to model multi-temporal overland flow dynamics in a shallow landslides-prone terraced landscape (northern Italy).The combined use of Remotely Piloted Aircraft Systems (RPAS) and photogrammetric techniques (e.g., Structure from Motion-SfM) allowed to elaborate multi-temporal high-resolution Digital Elevation Models (DEMs). Hydrological analyses of water flow's depth alterations due to the road presence were carried out adopting the SIMulated Water Erosion model (SIMWE), focusing on different scenarios considering the presence of the road and assuming its absence through a specific DEM smoothing procedure. The possibility to perform multi-temporal hydrological simulations at a hillslope scale so as to analyse the role played by the road in overland flows alteration is still a challenge to be investigated. Results proved the role played by the road in water flows change above the two observed shallow landslides, with respective maximum water depth values equal to 0.18 m and 0.14 m. On the contrary, no-road simulations not revealed significant water flows deviations towards landslides, with water depth values around 0 m, underlining that the absence of the road would avoid relevant changes in water flow paths toward the collapsed surfaces. This work could be a solid starting point for analyse road impact on runoff dynamics and hillslopes stability also at a wider scale, as well as for planning efficient mitigation intervention so as to reduce the occurrence of similar future scenarios.     

Plant litter decomposition influenced by soil animals and disturbance in a subtropical rainforest of Taiwan

Soil fauna has been postulated as one of the paramount determinants of decomposition in the humid tropics. However, its effect on litter decomposition has only been demonstrated in few forest sites in Central America. In addition, landslide is a common disturbance associated with heavy rainfall brought by tropical cyclones in the tropics and can potentially alter abundance and structure of soil animals and thus affect litter decomposition. In this study, we examined the effect of soil animals on litter decomposition in an Asian subtropical monsoon forest and compared the animal effects in landslide-disturbed (2 years old) and undisturbed sites. Animal exclusion by naphthalene treatment significantly reduced the density and diversity of litterbag animals and slowed down the rate of decomposition in both landslide-disturbed and undisturbed sites. However, density (per unit area) and diversity of the litter animals and litter decomposition rate did not differ between the landslide-disturbed and undisturbed sites for both control and animal-excluded treatments. Our data suggest that the abundance of soil animals is not limited by litter mass. Furthermore, soil fauna recover quickly from landslides, and fauna's facilitative effect on litter decomposition is not altered after their recovery.     

地震滑坡区覆盖生态毯对土壤湿度和养分的影响

为了研究生态毯覆盖对土壤湿度和养分的影响,首次将生态毯应用于地震滑坡区砾石泥沙堆积区和泥沙堆积区。结果表明:铺设生态毯的土壤含水量均高于裸地的;各层的土壤水分含量随干旱日数的增加呈下降的趋势,生态毯的下降趋势较为平稳;保水效果为椰纤维生态毯秸秆+椰纤维生态毯秸秆生态毯裸地。覆盖生态毯可以提高土壤有机质含量和p H值;土壤速效N、P、K和全N、全P、全K的含量也有一定程度的提高。铺设生态毯能有效固定地震滑坡区的砾石泥沙,改善土壤的水热条件,进而增加根系、微生物的活动和植被有机体的积累,促进枯落物的分解,逐步提高土壤中的养分含量。