An analysis of oasis stability in arid areas:a case study in the northern slope areas of the Tianshan Mountains

This paper discusses oasis stability at regional scale with a case study in the northern slope areas of the Tianshan Mountains (NSTM). The results showed certain significant aspects. (1) As long as water resources in the oasis keep stable and their utilization efficiency can be maintained or gradually increased, the primary productivity could be continuously increased and the natural primary productivity keeped relatively stable. In this case, it is considered that the oasis is stable and its sustainable development can be achieved at regional scale. (2) Considering the availability of water resources in the oases, the oases on the alluvial-diluvial fans are highly stable. In the alluvial plain downstream of the groundwater overflowing zones the oases are moderately stable and in the lacustrine deltas or dry lacustrine deltas the oases are lowly stable. (3) Enlargement of oases and the increase of water resources and vegetation coverage in the oasis will certainly enhance the 'cold-island effect' of the oasis and increase the stability of oases.

Analysis on Variations of the Temperature and Precipitation in North Slope Area of the Western Tianshan in Recent 50 Years

[Objective] The research aimed to analyze variation characteristics of the temperature and precipitation in north slope area of the Western Tianshan in recent 50 years.[Method] According to temperature and rainfall data from 1961 to 2010 at three meteorological stations in north slope area of the Western Tianshan,climate change in the zone in recent 50 years was analyzed by using linear trend analysis method and 5-year sliding average method.[Result] The temperature in north slope area of the Western Tianshan showed significant warming trend.The annual average temperature significantly increased at 0.3 ℃/10 a in recent 50 years.But rise rates of the temperature in different seasons were different:autumn> winter> spring> summer.The annual rainfall in north slope area of the Western Tianshan in recent 50 years overall presented relative increase trend.Seen from annual rainfall,it significantly increased at 16.9 mm/10 a.Seen from seasonal rainfall,except in autumn,rainfalls in other three seasons in the past 50 years all showed significant increase trends,with amplitude of 3.2-11.2 mm/10 a.The largest increase amplitude was in summer.After a small precipitation peak in the 1980s,autumn rainfall slightly declined in the past 20 years.[Conclusion] The climate in north slope area of the Western Tianshan become warm and wet.

Reservoir controlling differences between consequent faults and antithetic faults in slope area outside of source: A case study of the south-central Wenan slope of Jizhong Depression, Bohai Bay Basin, East China

The control effects of different occurrence faults on oil and gas accumulation and distribution in the outer slope area of oil and gas reservoirs were studied taking the south-central Wen’an slope of the Jizhong depression in the Bohai Bay Basin as an example.Based on 3D seismic data and the distribution of oil and water,the controlling differences between consequent fault and antithetic fault were analyzed and compared from the formation and evolution rule of faults and the formation mechanism of fault traps,including development positions of the consequent fault traps and antithetic fault traps,oil and gas distribution horizon adjusted by fault and formation period of fault traps.The differences between consequent faults and antithetic faults in controlling reservoirs have three main aspects:(1)Consequent fault traps and antithetic fault traps are in different positions,the consequent fault traps are at the segmented growing point in the hanging wall of"hard-linkage"faults,while the antithetic fault traps are developed in the position with the largest throw in the footwall because of tilting action;(2)The two kinds of faults result in different oil and gas distribution vertically,oil and gas adjusted by consequent faults is distributed in a single layer or multi-layers,while oil and gas adjusted by antithetic faults occur in single layers;(3)The two kinds of fault traps are formed in different periods,the consequent fault traps are formed at the time when the related faults enter the stage of"hard-linkage",while the antithetic fault traps are formed at the beginning of the fault active period.

Types,Characteristics and Significances of Migrating Pathways of Gas-bearing Fluids in the Shenhu Area,Northern Continental Slope of the South China Sea

The first marine gas hydrate expedition in China has been conducted by Guangzhou Marine Geological Survey in the Shenhu Area, northern continental slope of the South China Sea. Previous study has analyzed the P-T conditions, geophysical anomalies and saturation calculations of these gas hydrates, but has not documented in detail the migration of gas-bearing fluids in the study area. Based on the interpretations of 2D/3D seismic data, this work identified two types of migration pathways for gas-bearing fluids in the Shenhu area, i.e., vertical and lateral pathways. The vertical pathways（largescale faults, gas chimneys and mud diapirs） presented as steep seismic reflection anomalies, which could be traced downward to the Eocene source rocks and may penetrate into the Late Miocene strata. The deeper gases/fluids might be allowed migrating into the shallower strata through these vertical conduits. However, the distributions showed distinct differences between these pathways. Large-scale faults developed only in the north and northeast of the Shenhu area, while in the drilling area gas chimneys were the sole vertical migration pathways. Since the Pliocene, normal faults, detachment faults and favorable sediments have constituted the lateral pathways in the Shenhu gas hydrate drilling area. Although these lateral pathways were connected with gas chimneys, they exerted different effects on hydrate formation and accumulation. Gas-bearing fluids migrated upward along gas chimneys might further migrate laterally because of the normal faults, thereby enlarging the range of the chimneys. Linking gas chimneys with the seafloor, the detachment faults might act as conduits for escaping gases/fluids. Re-deposited sediments developed at the early stage of the Quaternary were located within the gas hydrate stability zone, so hydrates would be enriched in these favorable sediments. Compared with the migration pathways（large-scale faults and mud diapirs） in the LW3-1 deep-sea oil/gas field, the migration efficiency of the vertical pathways（composed of gas chimneys） in the gas hydrate drilling area might be relatively low. Description and qualitative discrimination of migration pathways in the Shenhu gas hydrate drilling area are helpful to further understand the relationship between good-quality deep source rocks and shallow, mainly biogenicallyproduced, hydrates. As the main source rocks of the Baiyun sag, lacustrine mudstones in the Wenchang and Enping Formations may provide thermogenic methane. Gas chimneys with relatively low migration efficiency created the vertical pathways. Caused by the Dongsha tectonic movement, the release of overpressured fluids might reduce the vertical migration rates of the thermogenic methane. The thick bathyal/abyssal fine-grained sediments since the Late Miocene provided migration media with low permeability. These preconditions may cause carbon isotopic fractionation ofthermogenic methane during long-distance vertical migrations. Therefore, although geochemical analyses indicate that the methane forming gas hydrate in the Shenhu area was mainly produced biogenically, or was mixed methane primarily of microbial origin, thermogenic methane still contribute significantly.

The Relationship between Tectonic Subsidence and BSR of Upper Neogene in the Deep-Water Area of the Northern Continental Slope, South China Sea

BSR （Bottom Simulating Reflector） occurs widely in the strata since the late Miocene in the deep-water area of the northern continental slope of South China Sea （SCS）. It is an important seismic reference mark which identifies the gas hydrate and its distribution influenced by the tectonic movements. Single-point basin modeling was conducted using 473 points in the study area. To discuss the relationships between the tectonic subsidence and BSR, the volume and rate of tectonic subsidence in each geological time have been simulated. The results show that there are three tectonic accelerate subsidence processes in the study area since the late Miocene, especially since 1.8Ma the tectonic subsidence accelerates more apparently. Since the Late Miocene to Pleistocene, the rate of tectonic subsidence in deep-water underwent a transformation from weak to strong. The ratio of tectonic subsidence to the total subsidence was relatively high （65-70%）. Through the superposition of the BSR developed areas and the contours of tectonic subsidence in this area, it was discovered that more than 80% of BSR tend to be distributed at the slope break or depression-uplift structural transfer zone and the average tectonic subsidence rate ranges from 70 m/Ma to 125 m/Ma.

玛西斜坡区风城组高含盐致密储集层流体识别

准噶尔盆地玛西斜坡区二叠系风城组发育碱湖沉积的高含盐致密储集层,其油水关系复杂,流体识别难度大。利用岩性扫描测井资料构建饱含盐水地层热中子宏观俘获截面,并利用测井热中子宏观俘获截面与饱含盐水地层热中子宏观俘获截面的差值构建含油性敏感因子,再利用氯元素相对产额与总孔隙度比值构建含盐度敏感因子,将含油性敏感因子与含盐度敏感因子交会形成流体识别图版。实例应用表明,利用该流体识别图版可以对储集层流体性质进行准确判断,为试油选层提供依据。

Quantitative analysis of biotechnical reinforcement for a steep slope consisting of composite coal-gangue-soil medium adjacent to a mined-out area

The engineering and geological characteristics of a steep slope consisting of coal gangue, rock and soil medium in Huating coal mine have been comprehensively investigated. Owing to humid weather, heavy rainfall, vegetation and porous characteristics of the soil and rock mass, the steep slope will be destabilized and induce mud-rock flow or derive hazard easily. Firstly, based on the classical slope reinforcement theory, some regularity between the shear and displacement in the destabilized zone of the slope with or without root strength contribution is presented. Then, based on the experimental and statistical analysis of root strength, hydrological characteristics and stability status, etc., some possible biotechnical techniques for reinforcement of the steep slope have been suggested. These methods are important for quantitative analysis of destabilization of the slope and design of the biotechnical reinforcement.

昆仑山北坡水资源科学考察初报

2021年10月首批启动了第三次新疆科学考察——“昆仑山北坡水资源开发潜力及利用途径科学考察”。结合多源遥感信息和2022—2023年野外科考工作,对昆仑山北坡的水文水资源变化和水资源利用进行了调查研究。结果表明:(1)1990—2020年,昆仑山北坡山区的气温、降水分别以0.14℃·(10a)^(-1)和6.53 mm·(10a)^(-1)幅度增加。(2)冰川变化相对稳定,积雪面积和积雪深度表现为略微增加。(3)永久性水体和季节性水体面积分别显著增加79.89%和144.49%。(4)东昆仑-库木库里盆地的阿牙克库木湖和阿其克库勒湖两大湖泊的水域面积分别增加了68.91%和58.22%,盆地内多条河流具备水资源开发潜力。(5)昆仑山北坡陆地水储量总体呈增加趋势,表现为从西向东增加趋势越加显著。(6)昆仑山北坡的主要河流和田河、克里雅河和车尔臣河年均径流量2010—2023年较1957—2023年分别增加了20.24%、27.85%和45.17%。(7)基于不同气候变化情景模拟预测至21世纪中后叶,主要河流径流量将保持上升态势,区域水资源量总体呈增加趋势。昆仑山北坡的水资源禀赋可为区域绿色高质量发展提供有利的水资源保障条件。

典型黑土区坡耕地表层土壤活性有机碳变化特征

以典型黑土区3种地貌类型区(漫川漫岗区、丘陵漫岗区、平原低地区)坡耕地不同坡位表层土壤为研究对象,通过测定土壤总有机碳、高活性有机碳、中活性有机碳和低活性有机碳等指标,分析黑土区坡耕地不同坡位表层土壤活性有机碳的变化特征,探究不同地貌类型区坡耕地土壤活性有机碳变化特征的差异。结果表明,坡耕地各坡位表层土壤总有机碳含量变化范围为26.57~38.61 g/kg,土壤活性有机碳含量变化范围为1.85~5.67 g/kg。3种地貌类型区坡耕地不同坡位土壤总有机碳和活性有机碳含量变化特征不同。漫川漫岗区总有机碳、中活性有机碳和低活性有机碳含量变化特征均表现为坡上和坡中显著大于坡下、坡上和坡中无显著差异;高活性有机碳含量变化特征则以坡中最高坡下最低,且不同坡位之间高活性有机碳含量差异显著。丘陵漫岗区不同坡位土壤总有机碳和低活性有机碳含量差异显著,并表现为坡下显著大于坡上、坡上显著大于坡中;高活性有机碳和中活性有机碳含量的变化则呈现坡上和坡下显著大于坡中、坡上和坡下无显著差异。平原低地区总有机碳及3种活性有机碳组分的含量在各坡位间的差异均为未达显著水平。不同地貌间典型黑土区坡耕地表层土壤活性有机碳分布规律有所差异,漫川漫岗区和丘陵漫岗区坡耕地土壤有机碳活性最差的坡位分别是坡下和坡中,而平原低地区不同坡位间无显著变化。研究结果为黑土坡耕地生态建设与保护技术的针对性设计奠定了理论基础。

江苏省宜兴地区碎石土滑坡地质灾害特征及防治措施研究

针对江苏省宜兴地区典型碎石土滑坡地质灾害,开展了滑坡地质灾害特征分析和防治措施研究。结果表明,碎石土滑坡主要发育于宜兴南部山区山前缓坡地带,自然边坡坡度不大于15°;滑坡体具有上土下岩的二元结构特征,滑坡破坏模式为后退式渐进整体变形破坏的牵引式滑坡,表现为地形改造+降雨诱发;滑坡体轴向水平距离为改造后边坡前缘高差的10.0~12.0倍。采用坡面修整、抗滑桩、回填压脚、挡土墙和截排水沟等综合防治措施可有效消除滑坡地质灾害隐患,坡体水平位移、垂直位移收敛于定值,坡体稳定。

西湖凹陷木广迎地区断陷层地质结构与油气勘探意义

西湖凹陷是东海陆架盆地内规模最大的富油气凹陷,保俶斜坡带是凹陷内油气勘探的主要地区。近期勘探实践表明,斜坡带深层构造—岩性领域具有良好的勘探前景。开展斜坡带北部木广迎地区深部断陷层地质结构与油气勘探潜力分析,对于明确西湖凹陷构造—岩性领域下步有利突破方向具有重要意义。本文综合利用高精度三维地震和钻井资料,开展木广迎地区精细的构造和层位解释。根据解释结果进行埋藏史—热演化史模拟,并系统分析区内油气地质条件。研究表明,木广迎构造带整体表现为东倾斜坡,北部发育古新统厚度中心;区内发育走向为NE、NNE和NW向的3组断裂,多数断裂的主活动时期为古新世—始新世,活动强度逐渐减弱;木广迎地区现今古新统残留厚度为200~1500 m,暗色泥岩厚度为100~700 m,最厚可达700 m以上,其主体于宝石组沉积时期进入成熟阶段;宝石组内发育大套厚层砂岩,且物性较好,可作为有利储层。研究认为,木广迎地区发育良好的生—储—盖组合和有效的源—储配置,是西湖凹陷斜坡带构造—岩性领域勘探的有利方向。

Tectonic analysis and petroleum significance of Cenozoic faults in Dongping-Niuzhong area in Altyn slope

The evolution process and petroleum significance of two groups of fault structures,the NW-SE trending and near EW trending ones in the Cenozoic of Dongping-Niuzhong area of the Altyn slope,Qaidam Basin,were investigated using high precision 3-D seismic data.The NW-SE faults were generated in Oligocene,causing the formation of a series of folds related to transpression faults in the Niuzhong and Dongping area.After the Miocene,with the continuous extension of the Altyn Tagh strike-slip fault zone,the EW trending faults began to develop massively in Altyn slope.The activity of near EW trending faults and large-scale uplift of the bedrock in the northern Niuzhong area shared most of the compression torsion in Niuzhong and Dongping area,consequently,the activity of NW-SE trending faults weakened significantly after the Miocene.Then good hydrocarbon source rocks developed in the inherited Jurassic sags.The faults were effective pathways for oil and gas migration in Dongping and Niuzhong areas,and the oil and gas charging time matched well with the formation period of the NW-SE trending faults and their related structures,making the fault-related anticlines favorable targets for oil and gas accumulation.The Niuzhong area has been less affected by the Cenozoic movement after the Miocene,and thus has better conditions for gas reservoir preservation.

三峡库区山区乡村功能多元化与坡耕地演变的耦合关系

探究快速城市化、工业化背景下,山区乡村功能多元化与坡耕地演变的耦合关系,对山区耕地保护和乡村可持续发展具有重要意义。从人地关系视角,构建了山区乡村功能多元化与坡耕地演变耦合关系测度模型,并以三峡库区奉节县为例,采用乡村功能评价、耦合协调度模型等方法,揭示其耦合关系及其驱动机制。结果表明:(1)奉节县各乡村功能均呈现发展的趋势,其中社会保障功能的发展最为明显,乡村功能综合指数呈现南北部增加、中部减少的特征,且南部增加幅度大于北部;(2)奉节县坡耕地占比呈现下降趋势,缓坡耕地减少最少,急陡坡耕地减少最多,呈现南部减少幅度小、北部减少幅度大的特征;(3)乡村功能多元化与缓坡耕地演变的耦合协调度呈下降的趋势,与陡坡耕地和急陡坡耕地的耦合协调度呈先降后升的趋势,其耦合响应类型可以归纳为可持续型、转型型、一致型和衰退型4种类型;(4)乡村功能多元化与坡耕地演变耦合变化主要受到自然、社会经济、政策等要素驱动,今后应当从发展生态农业、推行环境治理等方面来提高乡村功能发展与坡耕地利用之间的协调性。研究方法和研究结果可为其他山区坡耕地资源的优化利用、生态保护以及乡村可持续发展提供借鉴价值。

边坡监测与治理技术在高寒矿区露天煤矿生态修复中的应用研究

边坡治理是露天矿山生态修复中的重要内容之一。以青海木里矿区聚乎更区为例,针对高寒矿区露天煤矿的边坡问题识别、监测和治理开展了系统研究,通过遥感、物探、钻探及地表测量等手段研究了矿区内不稳定边坡发育特征及稳定性。研究结果表明:建立了以遥感技术为核心,辅以常规的地表监测、地质调查、物探及钻探等手段的“天空地时”一体化不稳定边坡探查监测体系,确定矿区内不稳定边坡发育特征及稳定性,为矿山修复治理针对性开展边坡治理提供依据;采用高危渣山降高减载和边坡减坡治理技术,对边坡台阶进行清坡处理,消除浮石和崩塌等灾害,对渣山削坡卸载,使采坑边坡和渣山边坡达到稳定状态;并以聚乎更4号井南渣山为例,根据高密度电法探测和钻探验证,识别出了常年冻土上限和渣土层与原采坑基岩界线两个滑移面,确定后缘载荷过大是导致滑坡的主要因素,采取“后缘降高减载+边坡减坡+水系连通+综合监测”的治理方案,治理后既消除了对边坡前缘的载荷,又为后期植被复绿提供了稳定的立地条件。多期次动态监测表明边坡后缘已趋于稳定;边坡监测及治理技术在木里矿区生态修复治理中得到广泛使用,治理后的渣山边坡坡度控制均小于26°,有效消除了不稳定边坡对修复治理的影响,保障了矿山生态修复治理成效。

砒砂岩区坡面产流产沙对土地利用方式的响应

[目的]研究坡面产流产沙过程对不同土地利用方式的响应于砒砂岩区生态保护与高质量发展具有重要意义。[方法]以十大孔兑罕台川流域的合同沟小流域为研究区,选取该区2016—2021年降雨产流产沙监测数据,应用聚类分析、双因素方差分析等,开展连续性动态监测研究,进而揭示砒砂岩区坡面产流产沙与不同土地利用方式的时空动态变化关系。[结果](1)次降雨按历时、雨强和雨量可分为3类,包括A类(历时短、雨量集中、高强度),B类(雨量较多、历时较短、中强度),C类(历时长、小雨强、雨量分散),C类导致水土流失能力最弱;(2)A,B类降雨产流产沙,排列顺序为乔木林地<灌草地<人工草地<天然草地<农作物地<裸地;C类降雨产流,排列顺序为乔木林地<天然草地<灌草地<人工草地<农作物地<裸地,产沙,排列顺序为人工草地<乔木林地<天然草地<灌草地<农作物地<裸地,且相同土地利用方式径流深和土壤流失量排序为C<B<A;(3)不同土地利用方式的径流深或土壤流失量对雨型响应的坡度效应略有差异,主要存在于裸地、农作物地与其他土地利用方式。[结论]砒砂岩区坡面水土流失的治理和生态恢复,应考虑雨型和坡度对不同土地利用方式产生的复合作用。

仪表着陆系统下滑信标运行保护区仿真研究

仪表着陆系统下滑信标运行保护区的科学防护,对于确保民用航空导航空间信号质量、保障航空器进近阶段运行安全、提升机场运行效率均具有重要意义。结合下滑信标运行保护区概念的演进,对民用航空国家标准、行业标准,以及国际民用航空公约附件十第I卷要求的下滑信标运行保护区的划设情况进行了对比分析。以特大型航空器A380-800为例,对特定运行类别的下滑信标运行保护区进行了研究,以期作为国际民用航空公约附件十第I卷关于下滑信标保护区相关数据的补充和实际工程论证的示例。给出了针对特定机场实际运行进行下滑信标场地保护的典型研究方法以及下滑信标运行保护区的保护建议,为机场的建设和运行提供参考。

西北寒旱区高速公路4种边坡防护形式植被恢复效果

在进行高速公路建设时,合理采用边坡防护形式可以很好的提高植被恢复效果。针对寒旱区环境和地质地貌特点,选取三维网植草、蜂巢格室,撒播植草和生态袋植草等4种公路边坡防护形式开展试验研究,通过测量土壤性质变化及植物生长情况探究不同防护形式对土壤环境营造和植物生长的影响。结果表明:4种防护形式都在不同程度上保证了植物生长,但植被恢复效果存在差异。蜂巢格室能够较好的改善土壤条件进而保障植物生长,其次为三维网植草,植被恢复效果较差的为撒播植草和生态袋防护形式。对于寒旱区高速公路边坡植被恢复宜采用蜂巢格室的防护形式,而对于有坡面稳定需求的边坡宜采用生态袋防护形式。

基于InSAR的乌东德水电站库区边坡形变监测及分析

水电站建成投产后,水库水位变化频繁,改变了库岸边坡原有的稳定性,易诱发边坡失稳破坏,从而对水电站的安全运行及周边居民区产生一定安全隐患。为了更好地掌握乌东德水电站蓄水过程中库区边坡的形变情况,通过SBAS-InSAR技术对该区域2020年5月至2022年8月间的升降轨哨兵数据进行解算,获取了研究区的地表形变特征;结合库水位变化情况、SAR数据反演出的边坡土壤含水量后向散射系数,对识别出的5处不稳定区域的形变机理进行分析。结果表明:运用升降轨InSAR可准确识别出库岸边坡的形变情况,研究区最大年平均沉降速率为-92 mm/a;库岸边坡的形变趋势与库水位及土壤含水量后向散射系数变化有着明显的相关性,水库蓄水是致使边坡体加速沉降的主要因素。

新构造运动对渤海凸起区、斜坡—洼陷区浅层油气最终成藏的控制作用

浅层新近系馆陶组—明化镇组为渤海的主力含油气层系。新构造运动是渤海新生代晚期发生的对油气成藏影响最为深刻的构造事件,对浅层油气成藏的影响远大于深层,控制了渤海浅层油气最终成藏。研究表明,新构造运动导致的凹陷晚期快速生排烃、多种类型圈闭发育、油气运移活跃等,整体上调整、控制了浅层油气藏的定型和分布,但对不同构造带浅层油气成藏的控制作用存在差异。根据构造位置和油气成藏特点,可将渤海浅层油气藏归为两大类:凸起区浅层油气藏、斜坡—洼陷区浅层油气藏。通过系统分析两类构造带浅层油气的成藏特点,明确新构造运动对两类构造带油气最终成藏的控制作用与富集模式差异,并构建了相应成藏模式。凸起区的浅层具有“晚期油源断层+浅层稳定储盖组合”的“台阶”型油气成藏模式;斜坡—洼陷区的浅层具有“洼中隆+晚期断层”“深层运移脊+晚期断层”两种“倒漏斗”型油气成藏模式。渤海浅层已进入了以岩性油气藏为主的勘探阶段,应加强新构造运动控制下的“晚期运移断层+岩性圈闭”组合勘探。

径流深和侵蚀量与集水面积、坡度及降雨量关系研究

[目的]分析径流深、侵蚀量与集水面积、坡度等影响因子间定量关系,为土壤侵蚀物理模型构建及参数率定提供参考。[方法]基于不同下垫面措施野外径流小区天然降雨实测资料,构建了年降雨径流深、侵蚀量多参数非线性估算模型。[结果]降雨产流阈值随集水面积、坡度呈先减后增、先增后减的变化趋势。年径流深(Y_(1))和年土壤流失量(Y_(2))随面积呈先增后减变化趋势;Y_(1)随坡度呈先减小后迅速增加变化趋势,Y_(2)随坡度呈持续递增变化规律;Y_(1)和Y_(2)随年降雨量持续增加。当坡面面积为130 m^(2)时,Y_(1)和Y_(2)均达最大值;当坡度为13.5°时,Y_(1)达最小值。Y_(1)多参数非线性回归估算模型精度较好,70%数据点相对误差分布在±30%内。[结论]集水面积、坡度和年降雨量三者交互作用对年降雨径流深和侵蚀量影响作用最大;对于年降雨径流深和侵蚀量而言,均存在临界集水面积和临界坡度值。