Temporal and spatial responses of ecological resilience to climate change and human activities in the economic belt on the northern slope of the Tianshan Mountains, China

In the Anthropocene era,human activities have become increasingly complex and diversified.The natural ecosystems need higher ecological resilience to ensure regional sustainable development due to rapid urbanization and industrialization as well as other intensified human activities,especially in arid and semi-arid areas.In the study,we chose the economic belt on the northern slope of the Tianshan Mountains(EBNSTM)in Xinjiang Uygur Autonomous Region of China as a case study.By collecting geographic data and statistical data from 2010 and 2020,we constructed an ecological resilience assessment model based on the ecosystem habitat quality(EHQ),ecosystem landscape stability(ELS),and ecosystem service value(ESV).Further,we analyzed the temporal and spatial variation characteristics of ecological resilience in the EBNSTM from 2010 to 2020 by spatial autocorrelation analysis,and explored its responses to climate change and human activities using the geographically weighted regression(GWR)model.The results showed that the ecological resilience of the EBNSTM was at a low level and increased from 0.2732 to 0.2773 during 2010–2020.The spatial autocorrelation analysis of ecological resilience exhibited a spatial heterogeneity characteristic of"high in the western region and low in the eastern region",and the spatial clustering trend was enhanced during the study period.Desert,Gobi and rapidly urbanized areas showed low level of ecological resilience,and oasis and mountain areas exhibited high level of ecological resilience.Climate factors had an important impact on ecological resilience.Specifically,average annual temperature and annual precipitation were the key climate factors that improved ecological resilience,while average annual evapotranspiration was the main factor that blocked ecological resilience.Among the human activity factors,the distance from the main road showed a negative correlation with ecological resilience.Both night light index and PM2.5 concentration were negatively correlated with ecological resilience in the areas with better ecological conditions,whereas in the areas with poorer ecological conditions,the correlations were positive.The research findings could provide a scientific reference for protecting the ecological environment and promoting the harmony and stability of the human-land relationship in arid and semi-arid areas.

Stability of bedded rock slopes subjected to hydro-fluctuation and associated strength deterioration

Reservoir-induced earthquakes(RIEs)occur frequently in the Three Gorges Reservoir Area(TGRA)and the rock mass strength of the hydro-fluctuation belt(HFB)deteriorates severely due to the reservoirinduced seismic loads.Three models of typical bedded rock slopes(BRSs),i.e.gently(GIS),moderately(MIS),and steeply(SIS)inclined slopes,were proposed according to field investigations.The dynamic response mechanism and stability of the BRSs,affected by the rock mass deterioration of the HFB,were investigated by the shaking table test and the universal distinct element code(UDEC)simulation.Specifically,the amplification coefficient of the peak ground acceleration(PGA)of the slope was gradually attenuated under multiple seismic loads,and the acceleration response showed obvious“surface effect”and“elevation effect”in the horizontal and vertical directions,respectively.The“S-type”cubic function and“steep-rise type”exponential function were used to characterize the cumulative damage evolution of the slope caused by microseismic waves(low seismic waves)and high seismic waves,respectively.According to the dynamic responses of the acceleration,cumulative displacement,rock pressure,pore water pressure,damping ratio,natural frequency,stability coefficient,and sliding velocity of the slope,the typical evolution processes of the dynamic cumulative damage and instability failure of the slope were generalized,and the numerical and experimental results were compared.Considering the dynamic effects of the slope height(SH),slope angle(SA),bedding plane thickness(BPT),dip angle of the bedding plane(DABP),dynamic load amplitude(DLA),dynamic load frequency(DLF),height of water level of the hydro-fluctuation belt(HWLHFB),degradation range of the hydro-fluctuation belt(DRHFB),and degradation shape of the hydro-fluctuation belt(DSHFB),the sensitivity of factors influencing the slope dynamic stability using the orthogonal analysis method(OAM)was DLA>DRHFB>SA>SH>DLF>HWLHFB>DSHFB>DABP>BPT.

Response of ecosystem service value to land use/cover change in the northern slope economic belt of the Tianshan Mountains, Xinjiang, China

Land use/cover change(LUCC)is becoming more and more frequent and extensive as a result of human activities,and is expected to have a major impact on human welfare by altering ecosystem service value(ESV).In this study,we utilized remote sensing images and statistical data to explore the spatial-temporal changes of land use/cover types and ESV in the northern slope economic belt of the Tianshan Mountains in Xinjiang Uygur Autonomous Region,China from 1975 to 2018.During the study period,LUCC in the study region varied significantly.Except grassland and unused land,all the other land use/cover types(cultivated land,forestland,waterbody,and construction land)increased in areas.From 1975 to 2018,the spatial-temporal variations in ESV were also pronounced.The total ESV decreased by 4.00×10^(8) CNY,which was primarily due to the reductions in the areas of grassland and unused land.Waterbody had a much higher ESV than the other land use/cover types.Ultimately,understanding the impact of LUCC on ESV and the interactions among ESV of different land use/cover types will help improve existing land use policies and provide scientific basis for developing new conservation strategies for ecologically fragile areas.

Construction of Forest and Grass Industry Economic Belt Using Land Resources in Road Side Slope

The construction of expressway and high-speed rail is at the sacrifice of the soil ecological environment. It brings about much damaged land and bare slope. It is necessary to restore vegetation and rebuild landscape. In the design of target plant community and configuration plants,it is required to select as far as possible plants that can blossom and bear fruit or pods. Then seeds of these plants can be harvested,processed and sold,and applied for other projects,so as to develop into a complete forest and grass seed industry chain. This not only reasonably utilizes land resources,but also provides a new approach to the problem of insufficient fine forest seed sources in China. This paper discussed the use of land resources in road side slope and forest and grass seed selection and breeding technology,and elaborated the industrialized development paths for forest and grass seed industries in road side slope. Finally,it arrived at following recommendations.( i) The construction of forest and grass industry economic belt using land resources in road side slope can realize maximum land value. Building a road can help people there get rich,and the type of land and water cultivates its type of forest and grass.( ii) It can make up for the losses incurred from construction of expressway and high-speed rail or destroying forest land,and it can increase farmers' income.( iii) It can increase the supply of domestic seeds,reduce seed import,save foreign exchange,and partly solve the problem of insufficient supply of forest and grass seeds.( iv) It is able to form a complete forest and grass seed industry economic cycle chain,increase employment,and provide new approaches for enriching and benefiting farmers.

Genetic Types and Exploration Significance of Slope Break Belt in Paleogene in Qikou Sag,Huanghua Depression,Bohai Bay Basin,Eastern China

Enrichment of hydrocarbon reservoir relates to the slope break types in continental basin(sag)in China. Division and analysis of genetic types of slope break will help to study the enrichment regularity of hydrocarbon reservoir and is conducive to the guiding of future development in exploration and enhancing prediction accuracy.This paper,guided by the theory of sequence stratigraphy and using high-resolution three-dimensional seismic data,drilling and other information,takes into account the characteristics

Dynamic damage evolution of bank slopes with serrated structural planes considering the deteriorated rock mass and frequent reservoirinduced earthquakes

To investigate the dynamic damage evolution characteristics of bank slopes with serrated structural planes,the shaking table model test and the numerical simulation were utilized.The main findings indicate that under continuous seismic loads,the deformation of the bank slope increased,particularly around the hydro-fluctuation belt,accompanying by the pore water pressure rising.The soil pressure increased and then decreased showed dynamic variation characteristics.As the undulation angle of the serrated structural planes increased(30°, 45°, and 60°),the failure modes were climbing,climbinggnawing,and gnawing respectively.The first-order natural frequency was used to calculate the damage degree(Dd)of the bank slope.During microseisms and small earthquakes,it was discovered that the evolution of Dd followed the“S”shape,which was fitted by a logic function.Additionally,the quadratic function was used to fit the Dd during moderately strong earthquakes.Through the numerical simulation,the variation characteristics of safety factors(Sf)for slopes with serrated structural planes and slopes with straight structural planes were compared.Under continuous seismic loads,the Sf of slopes with straight structural planes reduce stalely,whereas the Sf for slopes with serrated structural planes was greater than the former and the reduction rate was increasing.

Evolution of economic linkage network of the cities and counties on the northern slope of the Tianshan Mountains,China

The exchanges between cities and counties in the northern slope economic belt of Tianshan Mountains(NSEBTM)are increasingly frequent and the economic linkages are increasingly close,but the spatial distribution of economic development and linkages among the cities and counties within NSEBTM is uneven.Therefore,it is of great significance to study the evolution of spatial-temporal pattern of the economic linkage network of cities and counties on NSEBTM to promote the coordinated and integrated development of the regional economy on NSEBTM.In this study,we used the modified gravity model and social network analysis method to analyze the spatio-temporal evolution characteristics of the economic linkage network structure of cities and counties on NSEBTM in 2000,2010,and 2020.The results showed that the comprehensive development quality level of cities and counties on NSEBTM increased from 2000 to 2020,its growth rate also increased,and its gap between cities and counties continued expanding.Both the spatial distribution patterns of the comprehensive development quality level of cities and counties on NSEBTM in 2000 and 2010 were presented as“high in the middle and low at both ends”,while the spatial distribution pattern of 2020 was exhibited as“high value and low value staggered”.The total amount of external economic linkages of cities and counties on NSEBTM showed an obvious upward trend,and its gap between cities and counties continued expanding,presenting a pattern of“a strong middle section and weak ends”.The direction of economic linkages of NSEBTM existed obvious central orientation and geographical proximity.The density of economic linkage network of NSEBTM increased from 2000 to 2020,and the structure of economic linkage network changed from single-core structure centered with Urumqi City to multicore structure centered with Urumqi City,Karamay City,Shihezi City,and Changji City,shifting from unbalanced development to balanced development.In the future,we should accelerate the construction of urban agglomeration on NSEBTM,cultivate a modern Urumqi metropolitan area,improve comprehensive development quality of the cities and counties at the eastern and western ends,strengthen the intensity of economic linkages between cities and counties,optimize the economic linkage network,and promote the coordinated and integrated development of regional economy.

海拉尔盆地中部断陷带下白垩统南屯组致密储层特征及有利区预测

综合运用岩心分析、铸体薄片、高压压汞等资料,对海拉尔盆地中部断陷带下白垩统南屯组储层特征及其主控因素开展了详细研究,并对有利区进行了定量综合评价。研究结果表明:(1)海拉尔盆地中部断陷带南屯组岩石类型主要为岩屑砂岩和长石岩屑砂岩,储层孔隙度小于12%的样品数占总样品数的70.2%,渗透率小于1 mD的样品数占总样品数的66.3%,属于致密砂岩储层,储层储集空间主要为少量原生孔隙和大量次生溶蚀孔隙。(2)沉积相控制了研究区储层物性在空间上的总体分布规律,南屯组最有利的沉积相带是辫状河三角洲前缘和扇三角洲前缘亚相;压实作用对储层具有减孔效应,溶蚀作用普遍发育,形成了大量粒间和粒内溶孔,对储集性具有一定改善作用。(3)盆地中部断陷带发育缓坡断阶构造带、陡坡断阶构造带和洼槽带3种构造带,其中缓坡断阶构造带和陡坡断阶构造带为主要的油气聚集区带,其断裂的大量发育均早于或同期于烃源岩大量排烃阶段,为油气运移提供了通道。(4)将“沉积相-孔隙度-储层厚度-砂地比-埋藏深度”五要素进行叠合,定量评价有利储层发育区,其中Ⅰ类、Ⅱ类优质储层主要分布在盆地中部断陷带的缓坡断阶构造带和陡坡断阶构造带。

考虑消落带岩体劣化影响的典型危岩岸坡稳定性研究

三峡库区周期性水位升降引起的消落带岩体劣化对典型危岩岸坡稳定性具有重大影响。基于野外调研及地勘资料,采用通用离散单元法程序(universal distinct element code,简称UDEC)研究了消落带劣化区形态对近水平层状高陡危岩岸坡的稳定性影响。研究表明:目前三峡库区巫山段的近水平层状危岩岸坡消落带岩体劣化严重,在不同消落带劣化区存在紧密层状、松散碎裂状、溶蚀凹腔状、含挤压碎裂带等典型消落带劣化区形态;含有第1种消落带劣化区形态的危岩岸坡稳定性较好,危岩体位移较小,失稳模式为滑移破坏;含有第2种消落带劣化区形态的危岩岸坡危岩体先向坡内偏移,其后随着消落带岩体支撑强度弱化向坡外倾倒破坏;含有第3种消落带劣化区形态的危岩岸坡危岩体向坡外位移较大,失稳模式为倾倒破坏;含有第4种消落带劣化区形态的危岩岸坡稳定性主要受挤压破碎带的力学性质控制,易产生沿破碎带切割面的旋转滑移破坏;通过对以上4种劣化区形态的危岩岸坡增加防治加固措施,危岩体的变形位移得到了不同程度的有效控制。

天山北坡经济带城乡聚落格局变化与影响因素分析

以天山北坡经济带城乡聚落为研究对象,采用景观格局指数、地理信息系统(GIS)空间分析、位序-规模法等分析1980-2020年间城乡聚落格局的变化,结合地理探测器从自然、区位及社会经济因素探究城乡聚落格局的影响因素。结果表明:1980-2020年间,城乡聚落数量、规模持续扩张且趋于集聚,前20 a扩张以耕地、草地为主,后20 a以未利用地为主;城乡聚落密度变化显著,高密度区主要集中在各绿洲呈现“多核集中分布”特征,中密度区沿高密度区周围扩张,低密度区沿绿洲边缘分布并在非绿洲区有扩张;首位聚落规模发展较好,趋于位序-规模曲线,中型聚落略微发育,小型聚落数量持续减少;交通等区位因素是天山北坡城乡聚落格局的首位影响因素,社会经济因素次之,自然地理因素影响较小,各影响因素差异显著。

超大规模硬岩矿山源头推动TBM应用的设计创新与思考

西鞍山铁矿是一座超大规模开采矿山,采用TBM施工胶带斜井、斜坡道是该技术在国内地下铁矿山首次应用。TBM施工与钻爆法施工在勘察、设计和施工等方面均有较大差异,本文基于应TBM施工铁矿井巷工程,结合设备性能与开拓系统工艺需求,在斜井线路规划、曲线半径选择、始发场地设计、始发段与接收段支护、正常段支护选型、巷道底板处理、硐门设计形式等开展了应用创新。同时结合项目设计、施工中遇到的问题,对适用于矿山工程的TBM施工勘察技术要求、施工方案的选择及提高TBM施工断面利用率进行了分析与探讨。

三峡库区碳酸岩岸坡消落带岩体劣化特性

岸坡消落带是库水位升降形成的干湿交替作用区域。与岸坡其他地段相比,岸坡消落带水岩作用强烈,不断改造库岸的形貌特征,影响岸坡的整体或局部稳定性。消落带岩体劣化研究在劣化特征、劣化分类,以及劣化评价方法、指标研究方面存在不足。本文以三峡库区秭归和巴东干(支)流碳酸岩岸坡消落带岩体为研究对象,采取调(勘)查与试验、“比拟法”等综合分析方法,对碳酸岩消落区岩体劣化特征、过程及机制进行了系统研究,得到以下结论。(1)基于岸坡消落区岩体劣化的宏观效应,可划分为4种劣化类型;库水和地下水联动作用影响消落区岩体劣化的范围,沿深度方向呈现逐渐减弱的趋势,根据岩体劣化程度,可划分为3个区。(2)岩体各类结构面劣化最为严重,尤其是裂隙结构面,控制着岩体劣化的主要特征和类型。(3)库水作用方式和水的溶蚀性强弱影响岩体劣化的进展和演化发展模式。(4)根据库水与岸坡地下水联动程度,结合工程应用,提出了碳酸岩岸坡消落带岩体劣化的评价指标和评价方法。研究成果对消落带岩体劣化评价及岸坡稳定性演化评价具有一定的参考意义。

超压盆地水力破裂与天然气成藏的关系——以莺歌海盆地乐东斜坡区LD-A气田为例

莺歌海盆地乐东斜坡区LD-A气田的发现进一步证实了高温高压岩性圈闭领域的巨大资源潜力。该气田储层压力系数最高可达2.3,流体超压诱发的水力破裂对天然气的运聚起到重要的控制作用,明确超压条件下地层是否发生水力破裂及其演化过程是深入研究莺歌海盆地天然气成藏的关键。为此,在明确天然气垂向输导体系的基础上,以岩石破裂准则为理论依据,利用地应力及岩石抗张强度确定水力破裂模式,厘定了地层水力破裂条件;最终结合超压演化,分析了水力破裂动态演化过程对天然气成藏过程的控制作用。研究结果表明:(1)断裂、亚地震断裂和裂缝共同构成了LD-A气田天然气垂向输导体系,超压诱发的水力破裂控制了输导体系的启闭性和有效性,决定了天然气能否规模富集。(2)LD-A气田的中深层发育张性水力破裂,其中LD-A1气区现今黄流组顶部处于水力封闭状态,梅山组顶部处于水力渗漏状态;LD-A2气区和LD-A3气区上中新统黄流组顶部和中中新统梅山组顶部现今均处于水力封闭状态。(3)LD-A气田的水力破裂演化存在封闭—破裂—封闭型(LD-A1气区与LD-A2气区)和持续封闭型(LD-A3气区)2种类型,不同的水力破裂演化过程导致了天然气在不同层位砂体差异性充注和富集。结论认为,LD-A1气区与LD-A2气区浅层上新统莺歌海组二段和上中新统黄流组优质砂体是天然气有利富集对象,LD-A3气区应在埋藏更深的梅山组砂岩中寻找突破。

西湖凹陷平湖斜坡带物源-坡折耦合控砂模式

平湖斜坡带为西湖凹陷岩性油气藏勘探的重要区域之一。勘探开发实践证实,平湖斜坡带平湖组砂体展布复杂,控砂模式指导下的砂体刻画已成为岩性油气藏勘探突破的关键。从物源体系研究出发,结合坡折带特征分析,梳理了研究区物源坡折耦合控制下的砂体展布特征。沟谷及重矿物特征表明,研究区存在海礁隆起西部、西南部稳定物源及宝云亭凸起动态物源三大物源体系,控制了研究区储层沉积物来源;受隆起、断裂差异活动及沉积作用控制,研究区发育的断裂坡折、挠曲坡折和沉积坡折共同控制了研究区地形特征。物源体系与坡折耦合控制了沉积物从源到汇的动态过程:平湖组下段由西南物源及宝云亭凸起动态物源共同控制,发育混源堆积型控砂模式;平湖组中段由西部海礁隆起物源主控,以挠曲坡折限制的单源改造型控砂模式为主;平湖组上段由沉积坡折主控,发育缓坡过渡型控砂模式。

山地城市盾构连续皮带机力学分析及应用

针对山地城市轨道交通大纵坡渣土运输速度慢和易出现有轨运输溜车的难题,笔者采用有限元软件对隧道渣土连续皮带机进行了静力学分析,研究其应力、应变和位移分布规律,并对连续皮带机的现场应用效果进行总结。结果表明:输送带两端和中部位置处的应力、应变和位移较大,支架与托辊连接处易出现应力集中现象;支架可以有效为输送带提供支撑,减小输送带自身应力,限制输送带位移;采用连续皮带机出渣方式时的日平均进尺和日最高进尺相比渣土车出渣方式均有较大提高,盾构掘进效率得到明显提示。

西湖凹陷平北斜坡带平湖组层序构型差异及控砂模式

平北斜坡带是西湖凹陷岩性油气藏勘探的重点区带之一,但实际勘探过程中存在岩性砂体厚度小、横向变化大等问题,亟需开展不同构造单元内地层发育样式、沉积中心变迁、砂体发育机制等构造-沉积响应研究。基于最新钻井、测井及覆盖全区的高精度三维地震资料,开展了平北斜坡带平湖组三级层序-体系域高精度层序地层研究。基于古地貌、断裂体系的差异,划分了平北斜坡带构造-沉积单元,分析了不同单元内层序构型下断裂组合样式、地层接触关系、沉积充填样式的差异,探讨了不同层序构型差异的控制因素和控砂模式。研究表明,平北斜坡带可以划分为断裂陡坡型、对向断阶型、反向断阶型、顺向断阶型4种层序构型,层序构型差异受物源供给强弱变化、断裂体系活动差异、微古地貌转换调节、基准旋回迁移变化等控制,形成了4种砂体发育模式。通过不同构造单元层序构型差异和控砂机制研究,对于推动西湖凹陷平北斜坡带岩性油气藏领域勘探进程意义重大。

带式输送机防飘带技术应用研究

高曲矿18406底抽巷带式输送机设计时坡度较大,通常发生变坡点突然抬升22°,这会导致变坡点中间位置发生抬高。受地质构造的影响巷道坡度较大,皮带输送机在启动或空载运行过程中经常会产生“飘带”现象,基于此,对18406底抽巷大倾角带式输送机初始设计方案进行优化设计,并投入实践应用。当前,优化后的防飘带技术已运行近1年时间,变坡段未发生输送带飘带、跑偏、撕裂等安全事故发生,安全经济效益显著。

长距离螺旋斜坡连续皮带机控制系统设计

文章对某工程隧道连续皮带机控制系统设计方案进行了探讨。该工程具有大坡度、长距离、螺旋斜坡向下的特点,通过多点驱动实现了功率平衡以及长距离隧道急停的目的。

Physical Modeling of Landslide Mechanism in Oblique Thick-Bedded Rock Slope: A Case Study

The Jiweishan landslide illustrates the failure pattern of an apparent dip slide of an oblique thick-bedded rockslide. Centrifugal modeling was performed using a model slope consisting of four sets of joints to investigate the landslide initiation mechanism. Crack strain gauges pasted between the slide blocks and the base failed in sequence from the rear to the front as the centrifugal acceleration increased. When the acceleration reached 16.3g, the instantaneous failure of the key block in the front triggered the apparent dip slide of all blocks. The physical modeling results and previous studies suggest that the strength reduction in the weak layer and the failure of the key block are the main reasons for the Jiweishan landslide. The centrifuge experiment validated the previously proposed driving-blocks-key-block model of apparent dip slide in oblique with inclined bedding rock slopes. In addition, the results from limit equilibrium method and centrifuge test suggest that even though the failure of the key block in the front is instantaneous, a progressive stable-unstable transition exists.

A modified Hoek-Brown failure criterion considering the damage to reservoir bank slope rocks under water saturation-dehydration circulation

After water is impounded in a reservoir,rock mass in the hydro-fluctuation belt of the reservoir bank slope is subject to water saturationdehydration circulation(WSDC). To quantify the rate of change of rock mechanical properties, samples from the Longtan dam area were measured with uniaxial compression tests after different numbers(1,5, 10, 15, and 20) of simulated WSDC cycles. Based on the curves derived from these tests, a modified HoekBrown failure criterion was proposed, in which a new parameter was introduced to model the cumulative damage to rocks after WSDC. A case of an engineering application was analyzed, and the results showed that the modified Hoek-Brown failure criterion is useful.Under similar WSDC-influenced engineering and geological conditions, rock mass strength parameters required for analysis and evaluation of rock slope stability can be estimated according to this modified Hoek-Brown failure criterion.