Features of Sand-dust Deposits in Harbin City, China

1 Introduction The sand-dust storm weather, induced by special at- mospheric circulation in specifically geologic and geo- graphic environment, is disastrous one with little prob- ability and excessive harm. In China, the sand-dust storm frequency of every 10 years had increased from 4 times in the 1950s to 23 times in the 1990s (Zhuang et al., 2001). The sand-dust weather occurring in a large area of the northern China in the spring of 2002 had attracted much attention. People are gradually…     

Landslide mapping and analysis along the China-Pakistan Karakoram Highway based on SBAS-InSAR detection in 2017

The Karakoram Highway(KKH), a part of the China–Pakistan Economic Corridor(CPEC), is a major highway connecting northern Pakistan to China. The inventorying and analysis of landslides along KKH are challenging because of poor accessibility, vast study area, limited availability of ground-based datasets, and the complexity of landslide processes in the region. In order to preserve life, property, and infrastructure, and to enable the uninterrupted and efficient operation of the KKH, it is essential to strengthen measures for the prevention and control of geological disasters. In the present study, SBASInSAR(Small Baseline Subsets-Interferometric Synthetic Aperture Radar) was used to process 150 scenes of Sentinel 1-A images in the year 2017 along the Karakoram Highway. A total of 762 landslides, including 57 complex landslides, 126 rock falls, 167 debris slides, and 412 unstable slopes, ranging in size between 0.0017 and 10.63 km2 were identified. Moreover, this study also gains an inventory of 40 active glacier movements in this region. Landslide categorization, displacements characteristics, spatial distribution, and their relationship with various contributing factors have been successfully investigated along the entire KKH using image interpretation and frequency-area statistics. The criteria adopted for landslides categorization is presented in the study. The results showed that the 2-D ground deformation derived in Hunza valley echoes well with the general regional landslides characteristics. The spatial distribution analysis revealed that there are clumped distributions of landslides in the Gaizi, Tashkurgan, and Khunjerab in China, as well as in Hunza valley, and north of Chilas city in Pakistan. Statistical results indicated that these landslides mainly occur on south-facing slopes with a slope angle of 20°– 45° and elevation relief of 550 – 2,100 m. Landslide development is also related to low vegetation cover and weathering effects in mountain gullies. Overall, our study provides scientific data support and theoretical references for prevention, control, and mitigation of geological disasters in the Karakoram region.     

Climatology of Wind-Seas and Swells in the China Seas from Wave Hindcast

The wind-sea and swell climates in the China Seas are investigated by using the 27-yr Integrated Ocean Waves for Geophysical and other Applications(IOWAGA)hindcast data.A comparison is made between the significant wave height from the IOWAGA hindcasts and that from a jointly calibrated altimetry dataset,showing the good performance of the IOWAGA hindcasts in the China Seas.A simple but practical method of diagnosing whether the sea state is wind-sea-dominant or swell-dominant is proposed based on spectral partitioning.Different from the characteristics of wind-seas and swells in the open ocean,the wave fields in the enclosed seas such as the China Seas are predominated by wind-sea events in respect of both frequencies of occurrences and energy weights,due to the island sheltering and limited fetches.The energy weights of wind-seas in a given location is usually more significant than the occurrence probability of wind-sea-dominated events,as the wave energy is higher in the wind-sea events than in the swell events on average and extreme wave heights are mostly related to wind-seas.The most energetic swells in the China Seas(and other enclosed seas)are‘local swells’,having just propagated out of their generation areas.However,the swells coming from the West Pacific also play an important role in the wave climate of the China Seas,which can only be revealed by partitioning different swell systems in the wave spectra as the energy of them is significantly less than the‘local swells’.     

A NEW MARINE CILIATE, AMPHILEPTUS LITONOTIFORMIS NOV. SP. (PROTOZOA CILIOPHORA)

The morphology and infraciliature of a marine ciliate Anphi/eptus litonotiformis nov. sp. inhabiting a shrimp farming pond in Sheyang (Jiangsu Province) are described. According to the infraciliature, habitat . and other morphological characters, it can not be congeneric with any other species of the genus . The special features of A. litonotiformis are the Litonotus-like body shape and the arrangement of its extrusomes regularly located along the margin of the cytostome. The most important characters of some related Amphileptus-species from marine water are biometrically tabled and discussed.     

Molecular detection of microbial communities associated with Microcystis vs Synechococcus dominated waters in Tianjin,China

Harmful cyanobacterial blooms cause many ecological disasters worldwide. During the development of cyanobacterial blooms, the diversity and domination of cyanobacterial taxa are of a particular concern. In this study, the microbial community structure within a water system, such as in Yuqiao Reservoir and Haihe River in Tianjin City, China, was compared by using next-generation sequencing. A total of 5 001 operational taxonomic units were obtained and clustered from filtered 16 S rDNA V3–V4 region sequences. The cyanobacterial and microbial structures greatly differed in these two water areas. Microcystis was dominant in Yuqiao, whereas Synechococcus was dominant in Haihe. Proteobacteria species were dominant among all detected samples. The relative abundances of Bacteroidetes and Planctomycetes were higher in Yuqiao Reservoir than in Haihe River, whereas Firmicutes and Verrucomicrobia were relatively abundant in Haihe River. Further analyses indicated that the domination of both cyanobacteria was strongly related to several environmental factors, such as total nitrogen, total phosphorus, and dissolved oxygen, reflecting the role of trophic states in shaping the dominance of cyanobacterial taxa. The present study provided the example for Microcystis and Synechococcus dominance along a cyanobacterial bloom in north China. Applying highthroughput sequencing could offer a wide field of vision in analyzing microbial community structures.     

Risk assessment of secondary geological disasters induced by the Yushu earthquake

The Yushu Ms 7.1 earthquake occurred on April 14,2010 in Qinghai Province,China.It induced a mass of secondary geological disasters,such as collapses,landslides,and debris flows.Risk assessment maps are important for geological disaster prevention and mitigation,and also can serve as a guide for post-earthquake reconstruction.Firstly,a hazard assessment index system of secondary geological disasters in the earthquake region was built in this paper,which was based on detailed analysis of environmental and triggering factors closely related to geological disasters in the study area.GIS technology was utilized to extract and analyze the assessment index.Hazard assessment maps of secondary geological disasters were obtained by spatial modeling and overlaying analysis.Secondly,an analysis of the vulnerability of hazard bearing bodies in the area was conducted,important information,such as, population density,percentage of arable land, industrial and agricultural outputs per unit area were regarded as assessment indices to evaluate socioeconomic vulnerability.Thirdly,the risk level of secondary geological disasters of the area was obtained by the formula:Risk=Hazard×Vulnerability. Risk assessment maps were categorized into four levels,including"low","moderate","high"and"very high".These results show that some urban areas are at very high risk,including Jiegu,Chengwen,Xiaxiula and Sahuteng towns.This research can provide some references and suggestions to improve decisionmaking support for emergency relief and post- earthquake reconstruction in the study area.     

Developing a risk assessment system for gas tunnel disasters in China

Gas disasters always restrict the tunnel constructions in mountain area, which becomes a major geological barrier against the development of underground engineering. China is rich in coal resources and has a large amount of gas with a wide range of distribution. However, China experienced not only adverse effects on coal mining but also gas disasters in underground engineering construction, such as tunnels and chambers. With the increased number of tunnels passing through coal-bearing strata, the incidence of gas accidents is also rising. Therefore, the significance of preventing and mitigating gas disasters should be emphasized, and an effective risk assessment method for gas disasters should be established. On the basis of research on over 100 gas tunnels in China, a relatively ideal gas disaster risk assessment method and system for tunnels are established through the following measures. Firstly, geo-environmental conditions and gas situations were analyzed during construction. Secondly, qualitative analysis was combined with quantitative analysis. Finally, the influencing factors of gas disasters, including geological conditions, gas,and human factors, were investigated. The gas tunnel risk assessment system includes three levels:(1) the grading assessment of a gas tunnel during the planning stage,(2) the risk assessment of gas tunnel construction during the design and construction stages,(3) the gas tunnel outburst risk assessment during the coal uncovering stage. This system was applied to the dynamic assessment of gas disaster during the construction of the Zipingpu tunnel of Dujiangyan–Wenchuan Highway(in Sichuan, Southwest China). The assessment results were consistent with the actual excavation, which verified the rationality and feasibility of the system. The developed system was believed to be back-up and applied for risk assessment of gas disaster in the underground engineering construction.     

Oncholaimus zhangi sp. nov. (Oncholaimidae,Nematoda) from the intertidal zone of the East China Sea

A new species of free-living marine nematode is described from intertidal sediment of the East China Sea.The new species belongs to the Oncholaimidae family.Oncholaimus zhangi sp.nov.is characterized by males having a large ventral swelling situated just posterior to the middle of the tail,no precloacal papilla,and a row of 6–7 ventral genital setae.The tails of both males and females are similar,being conico-cylindrical in shape.The new species is distinguished from other closely related species by the presence of a prominent ventral swelling at the tail of males and a similar tail shape in both sexes.About 110valid species in this genus have been recorded to date.     

Long-term reconstruction of flash floods in the Qilian Mountains,China,based on dendrogeomorphic methods

In China, flash floods are one of the main natural disasters causing loss of life and damage to infrastructure. The threat of flash floods is exacerbated with climate change and increased human activities, such that the number of disasters has shown a clear upward trend in recent years.However, due to the scarcity of instrumental data or overly short timeseries, we are still lacking critical data to understand spatio-temporal patterns and driving factors of extreme flash floods. This missing kno...     

Risk assessment of maize drought disaster in southwest China using the Environmental Policy Integrated Climate model

The East Asian monsoon has a tremendous impact on agricultural production in China. An assessment of the risk of drought disaster in maize-producing regions is therefore important in ensuring a reduction in such disasters and an increase in food security. A risk assessment model, EPIC(Environmental Policy Integrated Climate) model, for maize drought disasters based on the Erosion Productivity Impact Calculator crop model is proposed for areas with the topographic characteristics of the mountainous karst region in southwest China. This region has one of the highest levels of environmental degradation in China. The results showed that the hazard risk level for the maize zone of southwest China is generally high. Most hazard index values were between 0.4 and 0.5,accounting for 47.32% of total study area. However,the risk level for drought loss was low. Most of the loss rate was 0.1, accounting for 96.24% of the total study area. The three high-risk areas were mainlydistributed in the parallel ridge–valley areas in the east of Sichuan Province, the West Mountain area of Guizhou Province, and the south of Yunnan Province.These results provide a scientific basis and support for the reduction of agricultural drought disasters and an increase in food security in the southwest China maize zone.     

广西荔浦石灰岩矿山地质环境保护与恢复治理

目前,矿山地质灾害主要表现在崩塌、滑坡、岩溶地面塌陷、泥石流等方面,对矿区进行地质灾害的预测并根据情况提出相应防治措施,能有效避免和减轻地质灾害造成的损失;同时也维护了矿区的正常作业和人民生命和财产安全。根据广西荔浦石灰岩矿山的地质环境条件,结合矿山地质环境问题的实地调查,在综合分析的基础上进行影响评估,并有针对性地提出了恢复治理措施。     

广西龙胜洪水河水电站地质灾害分析与防治措施

对龙胜县洪水河水电站的地质环境特征进行了调查研究,同时进行了地质灾害现状和预测的评估,在分析各种影响因素的基础上对存在的地质灾害和隐患提出了防治措施和建议,可为水电站建设过程中和建成运营后的地质灾害防治工作提供一定的理论依据。     

广西灌阳方解石矿矿山地质环境影响评估及治理恢复措施

在了解矿山基本情况基础上,结合野外实地调查和地质条件,从采矿活动引发的地质灾害、地下含水层破坏、地形地貌景观和土地资源的破坏等4个方面进行矿山地质环境影响评估。根据综合评估的结果,针对性地提出矿山地质环境治理恢复措施,有效避免和减少因矿山开采产生的地质灾害,恢复开采造成的地质环境破坏,维护矿区的生产生活及人身安全,为促进矿业经济的可持续发展提供科学依据。     

日照市地质灾害现状及防治建议

日照市地质灾害隐患点共计90处,灾害规模以小型为主。利用地质灾害危害程度评价、地质灾害稳定性、危险性评价及地质灾害易发程度综合分区评价,查明了地质灾害点分布位置,将地质灾害点的基本单元格进行现状、潜在地质灾害强度分析,其他基本单元格进行潜在地质灾害强度分析,确定各基本单元格易发程度。通过MapGIS软件,将相同易发程度的基本单元格合并连接成区,将地质灾害易发程度划分为高易发区、中易发区、低易发区,依据地质环境条件、地质灾害发育现状、灾害变化趋势、灾害危害特征,划分为重点、次重点和一般防治区,提出详细的地质灾害防治目标及对策建议,为日照市开展地质灾害预警预报示范区的建设工作提供了技术支撑。     

Risk-based evaluation on geological environment carrying capacity of mountain city - A case study in Suide County,Shaanxi Province,China

With the rapid development and expansion of the cities in China, the carrying capacity of resource and environment has become a huge concern for local governments. From the perspective of geological environment, geological disasters are the main restraining factor of the development in mountain cities. This study was conducted in Suide County of Shaanxi Province with a risk-based approach as followed: a hazard analysis on geological disasters based on a slope geological survey at a scale of 1:10,000; a consequence analysis based on unmanned aerial vehicle (UAV) aerial survey data; integrating the results of hazard analysis and consequence analysis, a risk zonation and analysis of geological disasters in urban areas were completed considering urban planning, land use planning and the safety of infrastructure and major engineering. Subsequently, taking the acceptable levels of human life and property risks incurred by landslides as the criteria of the evaluation of geological environment carrying capacity, a comprehensive assessment of current and future urban carrying capacity was conducted based on the results of the risk analyses. Accordingly, the prior development zone, the restricted development zone and the prohibited zone were delineated, with corresponding suggestions for future urban development. The technological and methodological system used in the study can be applied to geological environment carrying capacity evaluation of other important mountain cities, which can provide scientific basis for the optimization of land and space.     

十堰至天水高速公路磨河村隧道工程地质条件分析

通过对隧址区地形地貌、地层岩性、地质构造、岩土体工程地质特征等的调查,结合工程物探、地质钻探,岩体物理力学试验和地质测绘等勘察成果,分析了隧道洞身及进出口处围岩的稳定性,指出隧道施工过程中可能会遇到的工程地质问题,并提出了超前地质预报、支护、预防地质灾害、保护生态环境等施工措施和建议。     

莱芜市汛期地质灾害防治方案初探

莱芜市是一个矿产资源开采历史比较悠久的城市,也是一个地质灾害多发的地区。莱芜市国土资源局通过加强组织领导,组织专题宣传活动,修复治理损毁山体问题,加大日常监管措施,推进生产矿山的恢复治理等措施,取得良好的治理效果,矿山地质环境恢复治理率达66%,有效保护了当地的地质环境。     

广西龙胜曾家塘滑石矿地质灾害评估与防治

该文介绍了广西龙胜县曾家塘滑石矿地质灾害现状,在分析各种地质灾害形成原因及影响因素的基础上提出了相应的防治措施。为合理开发该滑石矿资源,保护矿山地质环境提供了科学依据。