44%of steep slope cropland in Europe vulnerable to drought

Steep-slope cropland plays a vital role in food production,economic development,ecosystem diversity,and Eu-ropean cultural heritage.However,these systems are susceptible to extreme weather events.The 2022 summer drought significantly impacted European agriculture,but the specific effects on steep-slope crops remain uncer-tain.Clarifying this is essential for comprehending similar future events and for implementing effective water management strategies to ensure the sustainability of steep-slope agriculture and associated ecosystem services.This study quantitatively analyzes the spatial distribution of twelve major European steep-slope(>12%)crops and assesses agricultural drought severity during the 2022 events using open-access spatial data.The satellite-based Vegetation Health Index(VHI)is utilized to identify critical hotspots.Results show that olive grove is the most widespread crop in steep slope agriculture(34%of total area),followed by wheat(24%),maize(16%),and vineyard(11%).Almost half of the steep-slope agriculture in Europe suffered drought during summer 2022.Vineyards were hardest affected at 79%,primarily in northern Portugal,northern Spain,southern France,and central Italy.Sunflowers followed at 62%,mainly in Spain,central Italy,southern France,and northern Roma-nia.Olive groves ranked third at 59%,with the most impact in northern Portugal,southern and central Spain,and southern Italy.Maize was also significantly affected at 54%.In this paper,we therefore highlight the need to increase steep-slope agriculture resilience by improving water management and promoting sustainable land practices.

Exploring mechanism of hidden,steep obliquely inclined bedding landslides using a 3DEC model:A case study of the Shanyang landslide in Shaanxi Province,China

Catastrophic geological disasters frequently occur on slopes with obliquely inclined bedding structures(also referred to as obliquely inclined bedding slopes),where the apparent dip sliding is not readily visible.This phenomenon has become a focal point in landslide research.Yet,there is a lack of studies on the failure modes and mechanisms of hidden,steep obliquely inclined bedding slopes.This study investigated the Shanyang landslide in Shaanxi Province,China.Using field investigations,laboratory tests of geotechnical parameters,and the 3DEC software,this study developed a numerical model of the landslide to analyze the failure process of such slopes.The findings indicate that the Shanyang landslide primarily crept along a weak interlayer under the action of gravity.The landslide,initially following a dip angle with the support of a stable inclined rock mass,shifted direction under the influence of argillization in the weak interlayer,moving towards the apparent dip angle.The slide resistance effect of the karstic dissolution zone was increasingly significant during this process,with lateral friction being the primary resistance force.A reduction in the lateral friction due to karstic dissolution made the apparent dip sliding characteristics of the Shanyang landslide more pronounced.Notably,deformations such as bending and uplift at the slope’s foot suggest that the main slide resistance shifts from lateral friction within the karstic dissolution zone to the slope foot’s resistance force,leading to the eventual buckling failure of the landslide.This study unveils a novel failure mode of apparent dip creep-buckling in the Shanyang landslide,highlighting the critical role of lateral friction from the karstic dissolution zone in its failure mechanism.These insights offer a valuable reference for mitigating risks and preventing disasters related to obliquely inclined bedding landslides.

Application of STEEP and Interpretive Structural Modeling in the Design Imagery of Taiwan Public Ceramic Relief Murals

Ceramic relief mural is a contemporary landscape art that is carefully designed based on human nature,culture,and architectural wall space,combined with social customs,visual sensibility,and art.It may also become the main axis of ceramic art in the future.Taiwan public ceramic relief murals(PCRM)are most distinctive with the PCRM pioneered by Pan-Hsiung Chu of Meinong Kiln in 1987.In addition to breaking through the limitations of traditional public ceramic murals,Chu leveraged local culture and sensibility.The theme of art gives PCRM its unique style and innovative value throughout the Taiwan region.This study mainly analyzes and understands the design image of public ceramic murals,taking Taiwan PCRM’s design and creation as the scope,and applies STEEP analysis,that is,the social,technological,economic,ecological,and political-legal environments are analyzed as core factors;eight main important factors in the artistic design image of ceramic murals are evaluated.Then,interpretive structural modeling(ISM)is used to establish five levels,analyze the four main problems in the main core factor area and the four main target results in the affected factor area;and analyze the problem points and target points as well as their causal relationships.It is expected to sort out the relationship between these factors,obtain the hierarchical relationship of each factor,and provide a reference basis and research methods.

THE EXISTENCE AND CONCENTRATION OF GROUND STATE SIGN-CHANGING SOLUTIONS FOR KIRCHHOFF-TYPE EQUATIONS WITH A STEEP POTENTIAL WELL

In this paper,we consider the nonlinear Kirchhoff type equation with a steep potential well−(a+b∫_(R)^(3)|∇u|^(2 )dx)Δu+λV(x)u=f(u)in R^(3),where a,b>0 are constants,λ is a positive parameter,V∈C(R3,R)is a steep potential well and the nonlinearity f∈C(R,R)satisfies certain assumptions.By applying a signchanging Nehari manifold combined with the method of constructing a sign-changing(PS)C sequence,we obtain the existence of ground state sign-changing solutions with precisely two nodal domains when λ is large enough,and find that its energy is strictly larger than twice that of the ground state solutions.In addition,we also prove the concentration of ground state sign-changing solutions.

LIMIT BEHAVIOR OF GROUND STATES OF 2D BINARY BECS IN STEEP POTENTIAL WELLS

We study the ground states of attractive binary Bose-Einstein condensates with N particles,which are trapped in the steep potential wellsλV(x)inℝ2.We show that there exists a positive number N*such that if N>N*,the system admits no ground state for anyλ>0.Moreover,there exist two positive numbers,M*andλ*(N),such that if N<M*,then for anyλ>λ*(N),the system admits at least one ground state.Asλ→∞,for any fixed N<M*,we give a detailed description for the limit behavior of both positive and semi-trivial ground states.

Field experiments on quantifying the contributions of Coreopsis canopies and roots to controlling runoff and erosion on steep loess slopes

Grass recovery is often implemented in the loess area of China to control erosion.However,the effect mechanisms of grass cover on runoff erosion dynamics on steep loess hillslopes is still not clear.Taking the typical forage species(Coreopsis)in semiarid areas as subject,this study quantified the effects of canopies and roots on controlling slope runoff and erosion.A series of field experiments were conducted in a loess hilly region of China.Field plots(5 m length,2 m width,25°slope gradient)constructed with three ground covers(bare soil;Coreopsis with intact grass;only roots of Coreopsis),were applied with simultaneous simulated rainfall(60mm h^(-1))and upslope inflow(10,30,50,70,90L min^(-1)).The results showed that compared with bare soil,intact grass significantly reduced runoff and soil loss rates by 16.6% and 62.4% on average,and decreased soil erodibility parameter by 66.3%.As inflow rate increased,the reductions in runoff and soil loss rates increased from 2.93 to 14.00 L min^(-1)and 35.11 to 121.96 g m^(-2)min^(-1),respectively.Canopies relatively contributed 66.7% to lowering flow velocity,turbulence,weakening erosive force and increasing hydraulic resistance.Roots played a predominant role in reducing soil loss and enhancing soil antierodibility,with relative contributions of 78.8% and 73.8%.Furthermore,the maximum erosion depth reduced by Coreopsis was at the upper slope section which was previously eroded the most.These results demonstrated the efficiency of Coreopsis cover in controlling runoff and erosion on steep loess slopes,especially under large inflow rates and at upper slope sections.We suggest protecting Coreopsis with intact grass at upper slope sections,while the aboveground grass biomass can be used for grazing or harvesting at middle and lower slope sections,with roots reserved.

浙江建设共同富裕示范区的STEEP模型分析

浙江在共同富裕道路上所做的努力探索与经验积累可从社会、技术、经济、生态、政策五个层面加以提炼概括。浙江成为中国首个共同富裕示范区与居民创业热情、人口流入能力、居民幸福指数、三大科创高地建设、经济能力、自然基础和生态文明建设表现以及社会治理能力等方面均走在全国前列分不开。基于浙江经验分析,可构建以政策力量为保障、以民生福祉为核心、以科学技术为支持、以经济基础为根本、以生态文明为关键的政府主导型“五位一体”共同富裕发展体系,以期为全国系统高效地推进共同富裕提供有益思路和参考。

石灰石露天矿高陡边坡稳定性计算分析

以西南某石灰石矿高陡边坡为研究对象,根据矿山边坡现状、边坡岩体结构和结构面发育特征因素对“现状边坡”和“终了边坡”进行地质分区,通过岩石室内物理力学试验获得坡体岩石物理力学参数,采用GSI法计算边坡岩体内摩擦角、粘聚力、变形模量和泊松比等参数,评估边坡地质强度特性,采用Morgenstern-Price极限平衡法分三种荷载工况分别计算“现状边坡”和“终了边坡”各分区稳定性系数。经分析,该石灰石矿各地质分区“现状边坡”和“终了边坡”稳定性好,采场边坡参数设计合理,可为矿山扩产安全设施设计和安全生产提供参考。

2022年四川省复杂地形下持续性极端高温特征与模式误差分析

2022年8月四川省持续性极端高温天气过程范围广、强度大且持续时间长,全省有74.8%的站点打破近70年历史同期极值。本文选取四川地区2022年8月逐时2 m气温实况站点和历史同期数据,结合EC、CMA-GFS及CMA-MESO模式的2 m气温预报数据,分析了此次极端高温天气特征及预报误差。结果表明:(1)受地形影响,最高气温极值呈东高西低的分布特征;(2)受热岛效应影响,最高气温超历史极值较多的站点主要集中在盆地西部龙泉山脉附近;(3)3个代表站的最高气温平均值高、距平大、高温持续时间长,该时段的累计降水量明显低于历史同期平均值且降水日数显著偏少;(4)3个模式对于最低气温的预报准确率明显高于最高气温,而最优模式的高温预报准确率仅39.1%;(5)EC模式的预报优势主要在盆地低海拔站点,CMA-MESO模式在陡峭地形区域的预报效果要优于EC模式;(6)对于最高气温出现日期预报,EC模式在盆地和攀西地区效果更佳,CMA-GFS和CMA-MESO模式在川西高原效果更优。

米曲霉发酵100%玉米浆的工艺条件优化

为开发玉米浆资源化利用的新途径,该文采用米曲霉(Aspergillus oryzae)对100%玉米浆进行发酵制备食用菌营养剂。首先在100%玉米浆固体培养基中连续驯化米曲霉,获得对100%玉米浆更耐受的米曲霉菌株,然后建立米曲霉发酵100%玉米浆的最佳工艺条件。结果表明,与原始菌株相比,在100%玉米浆固体培养基上连续驯化4次后,米曲霉的菌丝形成和孢子成熟时间分别缩短了40%和30%;将驯化后的米曲霉接种于100%玉米浆中进行发酵,可溶性蛋白和氨基酸态氮含量分别增加了3.38%和3.00%。以驯化米曲霉为发酵菌株,采用单因素试验和正交试验确定米曲霉发酵100%玉米浆的最佳工艺条件为:接菌量1.25×10^(5)孢子/100 mL、装液量90 mL/250 mL、初始pH 5.9,发酵温度25℃,发酵时间8 d。在此条件下,氨基酸态含量和可溶性蛋白含量分别为(21.75±0.12)mg/mL和(18.25±0.08)g/100 mL,分别比未发酵玉米浆提高了71.67%和10.74%。

基于光纤感测的急倾斜煤层采动围岩变形特征研究

将分布式光纤传感技术应用于急倾斜煤层采场围岩变形及应力分布特征物理相似模型试验,通过在模型中沿煤层倾向布置传感光纤与沿煤层底板铺设压力传感器,实时监测模型内部变形场与应力场,并结合数值模拟分析了急倾斜煤层顶板应变分布及演化特征。结果表明:工作面上部区域应力值小于下部和中部区域,中部区域应力值最大;随工作面推进,采空区底板应力逐渐释放,应力值不断降低,采空区两侧边界煤柱下方煤层底板应力逐渐升高,且中、下部采空区底板应力恢复程度显著高于上部底板;沿煤层倾向布置的光纤应变曲线呈三段分布,具有前后2处应变波峰区及采空区对应的中部波谷区,前波峰远高于后波峰;工作面中上部顶板变形程度大于下部顶板;数值模拟与光纤检测结果一致,均表现出中上部顶板变形显著大于下部。研究弥补了物理相似模型试验监测手段短板。

基于离散元方法的急倾斜极薄矿脉机械化开采爆破参数仿真优化

急倾斜极薄矿脉留矿法开采爆破空间规整平齐是实现小型采矿机器人高效通行和稳定作业的关键因素。为了提高狭小空间爆破光面控制效果,采用离散元方法和黏结颗粒模型耦合仿真方法,开展了不同炮孔参数条件下急倾斜极薄矿脉爆破模拟,以爆破空间轮廓规整性系数为评价指标,对急倾斜极薄矿脉炮孔布置方式和参数进行了优化。研究结果表明:同等排距和孔距条件下,矩形方式布孔的爆破规整性系数最高,矩形+间隔空孔布孔方式爆破规整性系数次之,之字形炮孔布置方式爆破效果最差;结合爆破经济性指标和采场断面规整性系数综合考虑,对于急倾斜极薄矿脉机械化开采,推荐采用矩形+间隔空孔装药的爆破方式,炮孔排距0.4 m,孔距0.8 m。

高海拔铁路隧道斜井机械化配套与快速施工

为解决高海拔高寒地区斜井施工存在气压低、含氧量低、温差大、严寒干燥等问题,以某高海拔铁路隧道斜井工程为背景,结合围岩等级、断面大小、海拔高度,根据斜井施工机械化配套原则,提出高海拔陡坡长斜井机械化安全快速进洞施工工法,并选配超前支护、钻爆、装运、喷锚支护、衬砌等机械化作业线的成套设备。基于高度机械化的设备配套,提出“快挖、快运、快支”的高效施工技术以及各工序快速衔接工艺。以控制围岩变形为核心,构建一套积极干预加固围岩、注重早期支护并快速闭合的主动支护体系。结果表明:与普通钻爆法施工相比,采用三臂凿岩台车高度机械化配套施工效率高,月最快进尺为180 m,较人工钻爆法施工月进尺为130 m相比提高了近30%,施工质量稳定,作业人员投入少,且拱顶沉降和周边收敛均小于规范要求值,衬砌强度可靠,可实现高海拔小断面隧道“快挖、快支、主动支、快封闭”。

急倾斜巨厚煤层复杂空间结构区微震时空演化规律及诱冲机理

煤矿冲击地压灾害的发生与空间结构密切相关,尤其在复杂空间结构区灾害发生更频繁。掌握煤层开采复杂空间结构区煤岩灾变规律并揭示其发生机制对于冲击地压防控具有重要意义。以乌东煤矿为研究背景,采用数值模拟、微震监测、理论分析等方法,研究了岩柱应力异常尺寸效应,分析了复杂空间结构区微震时空演化规律,揭示了复杂空间结构下冲击地压发生机理,评估了煤层开采不同区域的冲击危险性。研究结果表明:①急倾斜岩柱厚度更窄、出露高度更大其撬动效应更强,岩厚变异应力异常形成5个分区。②岩柱厚度更窄区域微震频次更多,能量更高,时空活动度更强,离散性更高。高应力区、应力梯度区、应力平稳区依次呈现“低频次-高能量”、“高频次-高能量”、“低频次-低能量”的微震响应特征。③特殊空间结构区域微震事件簇集且能级增大,时空活动度及离散性陡增,尤其在结构边缘该特征更明显,能量积聚及释放速率增大,冲击地压发生的概率及强度更高。位于岩柱更窄区域的特殊空间结构内微震活动更剧烈。④岩柱厚度越窄(煤柱高度越大)则岩柱向深的弯矩及能量增长速率越快,冲击危险性更高。依据结构面强度效应推断出断裂带发生滑移错动,是能量积聚与释放的优势区域。揭示冲击地压发生机理为高静载及低临界载荷共同作用,基于应力集中特征评估煤层开采不同区域的冲击危险性。

露天矿高陡复杂边坡软弱岩层组“坐落-滑移式”破坏模式研究

边坡稳定性问题随露天矿开采的进行不断突出,而边坡软弱岩层严重影响边坡稳定性。大量工程实例显示,露天矿含软弱岩层组的高陡复杂边坡失稳模式通常为“坐落-滑移式”破坏。为明晰露天矿高陡复杂边坡软弱岩层组“坐落-滑移式”破坏模式的破坏机理,以某露天矿为例,提出一种针对露天矿含软弱岩层组高陡复杂边坡的综合分析方法。研究结果表明:采用工程地质分析、传统极限平衡方法和数值模拟分析相结合的综合分析方法,针对该类型复杂边坡可发挥不同分析方法的优势,较全面地从地质自然环境条件、定性定量方面、应力应变角度分析边坡破坏机理及模式,总结归纳出含软弱层组露天矿高陡复杂边坡“坐落-滑移式”破坏的“坐落-滑移-剪出”三段式破坏特征,为其他类似复杂边坡稳定性的分析和防治提供思路和手段。

川东地区高陡构造带寒武系洗象池群天然气成藏条件

利用岩心、测井与地震资料,采用地震解释、平衡剖面以及包裹体检测等技术,恢复了川东地区高陡构造带的构造演化史,并对平桥、建南、梓里场构造的天然气来源、运聚与保存条件进行了分析。研究结果表明:(1)川东地区平桥断背斜圈闭东翼的单条逆断层使得下盘的龙马溪组烃源岩与上盘的洗象池群储层发生了侧向对接,天然气可穿过断裂带向上盘储层运移,具备较好的输导条件,且圈闭盖层未受到断裂作用破坏,保存条件良好,有利于天然气的聚集成藏。(2)建南断背斜圈闭翼部的多条平行的逆断层虽然实现了部分源-储对接,但是多条断层组合降低了其侧向输导能力,天然气未能大规模聚集。(3)梓里场断背斜圈闭的源-储配置与输导条件优良,但盖层的封盖能力较差,大多被断层破坏,钻探显示储层为水层。(4)川东地区高陡构造带寒武系洗象池群天然气聚集成藏的主控因素包括:断层或断层组合控制下的源-储配置、侧向输导条件以及盖层的封盖能力。

渝利铁路绿春坝隧道危岩体整治防护设计

以渝利铁路绿春坝隧道陡坡危岩体为例,通过现场调研得到危岩体发育特征及其稳定性,进行现场滚石试验,然后采用ROCKFALL软件对危岩落石滚落轨迹及能量分布进行数值模拟。根据数值分析结果采取分区清除、分级防护、拦石墙与消能措施相结合的综合处理措施。

陡坡段穿越溶洞桩基竖向承载特性离心试验

为了研究陡坡段桥梁桩基穿越溶洞时的竖向承载特性,利用离心模型试验,研究陡坡坡度一定时,桩顶竖向荷载作用下溶洞高度变化对桩基础荷载-沉降曲线、桩基极限承载力、桩身轴力及桩侧阻力的影响,给出影响桩基竖向承载特性的关键参数.结果表明,在桩长及桩基入岩总深度一定的情况下,桩基竖向极限承载力随溶洞高度的增大而减小,极限承载力减幅随溶洞高度的增大而增大.当洞高小于1.2倍桩径时,极限承载力的减幅不明显.当洞高大于2.4倍桩径时,极限承载力的减幅显著增大.桩身轴力的衰减速度在粉质黏土层内较小,在持力层内较大,在溶洞范围内基本不衰减.当洞高大于2.4倍桩径时,持力层范围内的轴力衰减幅度显著增大.桩侧阻力在持力层内显著大于上部岩土层,在溶洞范围内几乎为零.随着溶洞高度的增大,桩基础竖向极限承载力中桩侧阻力的占比逐渐减小,当洞高大于2.4倍桩径时,桩侧阻力减小了65.5%,桩基由摩擦桩逐渐向端承桩转化.

基于地形因子的震后泥石流降雨阈值分析

为了探索都江堰—汶川G213线宽缓窄陡泥石流的降雨阈值,利用地震前后的遥感影像及地理信息系统(geographic information system,GIS)技术,提取研究区43条沟的地形因子;基于主成分分析法和SPSS软件分析各因子的相关性,建立综合地形因子临界模型;通过引入降雨因素利用支持向量机分类模型得到不同沟道形态的降雨阈值模型。结果表明:综合地形因子以0.51为沟道形态分界线,大于0.51为窄陡型沟道,小于或等于0.51为宽缓型沟道,利用北川部分沟道进行模型验证,准确性达99%;基于综合地形因子所划分的沟道类型,通过研究区降雨数据进行数学分析得到综合地形因子和降雨因素之间的影响系数,利用随机向量机分类模型,对获得宽缓与窄陡沟道的降雨强度I和降雨历时D数据,建立I-D降雨阈值模型,I-D降雨阈值模型表明影响系数越大,地形因子就大,越利于泥石流的发生,激发泥石流所需的降雨阈值就越小,此类泥石流为窄陡型泥石流,反之亦然。研究成果可为不同区域、沟道类型、时间段的震后泥石流降雨阈值提供参考。

基于三维激光扫描的高陡边坡勘查与支护设计

以广东清远银湖城复杂高陡边坡为依托,采用三维激光扫描技术,查明边坡的空间展布形态、优势结构面的空间分布特征,为边坡设计提供依据。基于三维激光扫描调查和边坡稳定性评价结果,对挖方土岩组合高边坡,上部土体采用“放坡+锚杆格构梁”,中下部岩体采用“削坡+马道挡石墙”的治理措施;对填方边坡,采用“强夯加固+扶壁式或重力式挡墙直立式支挡+坡率加筋土+坡面浆砌石格构梁防护相结合”的治理措施。生态修复效果良好,经济效益显著。