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Evaluating coastal lagoon sustainability through the driver-pressure-state-impact-response approach: a study of Khenifiss Lagoon, southern Morocco 通过 "驱动因素-压力-状态-影响-反应 "方法评估沿海泻湖的可持续性:对摩洛哥南部 Khenifiss泻湖的研究
IF 2.9 3区 地球科学 Q3 GEOSCIENCES, MULTIDISCIPLINARY Pub Date : 2024-06-21 DOI: 10.3389/feart.2024.1322749
Hamza El Behja, Abdelmounim El M’rini, Driss Nachite, Mohammed Bouchkara, Khalid El Khalidi, Bendahhou Zourarah, Md Galal Uddin, Mohamed Abioui
Coastal lagoons are valuable ecosystems, providing socioeconomic benefits and supporting human populations and biodiversity. However, these systems face several challenges, making them vulnerable to both natural and human factors. In this study, we apply the Driver-Pressure-State-Impact-Response (DPSIR) Approach to conduct a comprehensive socioeconomic and environmental assessment of the Khenifiss Lagoon to promote sustainable development and support decision-makers. Located on the southern Atlantic coast of Morocco, the lagoon was designated a natural reserve in 1962, a biological reserve in 1983, and a protected wetland under the Ramsar Convention since 1980. This study represents the initial endeavor to conduct a comprehensive global and multidisciplinary environmental assessment of the lagoon by using a wide range of data sources, including relevant publications and reports, satellite images and remote sensing data, field observations, and interviews, all analyzed under the DPSIR framework. Our findings show that both natural and human factors have an impact on the ecosystem. Natural Factors associated with the geomorphological features of the region likely contribute to the silting of the lagoon, possibly intensified by a large shipwreck stuck at its inlet. Meanwhile, human factors encompass population growth (at a rate of 2% per year), tourism, shellfish farming, fishing, shellfish harvesting, and salt extraction. Our results reveal significant changes in the lagoon’s condition in recent years, including a reduction in water body extent, a probable decrease in depth, and an increase in the accumulation of solid waste, plastics, and wastewater in three sectors spanning a total surface area of 464 ha (equivalent to 7% of the lagoon), a substantial expansion of the salt mining area encompassing 368 ha, and a remarkable loss of biodiversity, manifested in declining fish stocks and seabird populations. This study showed that the lagoon is positioned as a potential site for economic growth and serves to alert stakeholders and the local population to the ecosystem’s environmental issues. Based on the findings of this study, we highly recommend regulating human activities within the lagoon, the removal of the wreck at the entrance, proper waste management, community awareness programs, and strict monitoring and enforcement of regulations to protect the environment.
沿海泻湖是宝贵的生态系统,可提供社会经济效益,并为人类和生物多样性提供支持。然而,这些系统面临着一些挑战,使其容易受到自然和人为因素的影响。在本研究中,我们采用 "驱动因素-压力-状态-影响-响应(DPSIR)"方法对 Khenifiss 泻湖进行了全面的社会经济和环境评估,以促进可持续发展并为决策者提供支持。该泻湖位于摩洛哥南部大西洋沿岸,1962 年被指定为自然保护区,1983 年被指定为生物保护区,1980 年被指定为《拉姆萨尔公约》保护湿地。这项研究是对该泻湖进行全面的全球多学科环境评估的首次尝试,它使用了广泛的数据来源,包括相关出版物和报告、卫星图像和遥感数据、实地观察和访谈,所有这些都在 DPSIR 框架下进行了分析。我们的研究结果表明,自然和人为因素都会对生态系统产生影响。与该地区地貌特征相关的自然因素可能是造成泻湖淤塞的原因之一,而泻湖入口处的一艘大型沉船可能加剧了淤塞。与此同时,人为因素包括人口增长(每年 2%)、旅游业、贝类养殖、捕鱼、贝类捕捞和采盐。我们的研究结果表明,近年来泻湖的状况发生了重大变化,包括水体范围缩小,水深可能下降,固体废物、塑料和废水在总面积为 464 公顷(相当于泻湖面积的 7%)的三个区域的积累增加,盐矿开采区面积大幅扩大,达 368 公顷,生物多样性显著丧失,表现为鱼类种群和海鸟数量减少。这项研究表明,泻湖被定位为一个潜在的经济增长点,并提醒利益相关者和当地居民注意生态系统的环境问题。根据这项研究的结果,我们强烈建议对泻湖内的人类活动进行监管,拆除入口处的沉船,进行适当的废物管理,开展社区宣传计划,并严格监督和执行法规,以保护环境。
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引用次数: 0
Experimental and numerical studies on CO2 injectivity in low permeability oil reservoirs 低渗透油藏二氧化碳注入率的实验和数值研究
IF 2.9 3区 地球科学 Q3 GEOSCIENCES, MULTIDISCIPLINARY Pub Date : 2024-06-20 DOI: 10.3389/feart.2024.1418087
Fankun Meng, Lin Cao, Yuhui Zhou, Botao Liu, Chengyue Wen, Jia Liu
Introduction: Contrary to the traditional recognition that CO2 has large injectivity (the ratio of CO2 injection volume to pressure drop) in low permeability oil reservoirs to keep the formation pressure at a high level, the CO2 injection rate usually cannot attain the set value. It is essential to study the factors that influence CO2 injectivity and propose the optimal strategies to improve the CO2 injectivity.Methods: Therefore, in this study, several core samples collected from low permeability oil reservoirs are used to experimentally investigate the influences of CO2 injection rate, formation permeability, pressure and water saturation on CO2 injectivity, and the corresponding pressure drop, oil and gas production are examined. To determine the primary factor that influences the CO2 injectivity, orthogonal experimental design (ODE) and numerical simulations are utilized. In addition, to improve CO2 injectivity, the techniques of mini-fracturing and radial perforation are presented, and the threshold values for these two parameters are determined.Result and discussion: The results demonstrate that according to the magnitude of the extent that influences CO2 injectivity, the rank for the above factors is CO2 injection rate, reservoir pressure, formation water saturation and permeability. The oil recovery is mainly influenced by CO2 injection rate and formation permeability, and the influences of reservoir pressure and water saturation on oil recovery are smaller. The threshold values for radial perforation and fracture half-length are 25 m and 50m, respectively, which can provide some guidance for the strategies that should be taken to improve the CO2 injectivity and recover more oil from low permeability oil reservoirs.
导言:传统认识认为,在低渗透油藏中,二氧化碳具有较大的注入率(二氧化碳注入量与压降之比),可使地层压力保持在较高水平,但与之相反,二氧化碳注入率通常无法达到设定值。研究影响二氧化碳注入率的因素并提出提高二氧化碳注入率的最佳策略至关重要:因此,本研究利用从低渗透油藏采集的几个岩心样本,实验研究了二氧化碳注入率、地层渗透率、压力和水饱和度对二氧化碳注入率的影响,并考察了相应的压降和油气产量。为确定影响二氧化碳注入率的主要因素,采用了正交实验设计(ODE)和数值模拟。此外,还介绍了提高二氧化碳注入率的微型压裂和径向射孔技术,并确定了这两个参数的临界值:结果表明,根据影响二氧化碳注入率的程度大小,上述因素的排序依次为二氧化碳注入率、储层压力、地层水饱和度和渗透率。采油率主要受 CO2 注入率和地层渗透率的影响,储层压力和含水饱和度对采油率的影响较小。径向射孔临界值和裂缝半长临界值分别为 25 米和 50 米,这可以为提高低渗透油藏的二氧化碳注入率和提高采油率提供一定的指导。
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引用次数: 0
Transition of dome formation to sudden explosive eruptions at Popocatépetl, Mexico: magnetic indicators 墨西哥波波卡特佩特尔从圆顶形成到突然爆炸性喷发的过渡:磁性指标
IF 2.9 3区 地球科学 Q3 GEOSCIENCES, MULTIDISCIPLINARY Pub Date : 2024-06-20 DOI: 10.3389/feart.2024.1204859
Ana Lillian Martin-Del-Pozzo, César Alberto Santos Morales
Transitions from effusive to explosive activity can increase hazards making it crucial to define early indicators such as changes in the magnetic signals. After more than 80 cycles of crater-dome extrusion and destruction from 1996 on, Popocatépetl volcano (Mexico) experienced changes in its behavior from March 15 to 18 July 2019, when no lava domes were observed. Some of the domes behaved as contained lava flows within the crater floor (pancakes) while others were more irregular-shaped. Activity decreased considerably over this 2019 interval except for the unexpected explosions in March and June, that produced ash plumes reaching up to 14,000 m a.s.l. In order to investigate the causes of the transition from effusive to explosive behavior in March and June, we analyzed the time series from the magnetic monitoring network at Popocatépetl volcano between October 2018 and December 2019. The raw signals were analyzed by weighted differences (WD) based on the elimination of non-local changes from the total intensity values of the geomagnetic field and the discrete-time continuous wavelet transform was used to evaluate the local variations of energy within the time series. The high energy periods (linked to negative magnetic anomalies) are induced by magma ascent associated with movement within the conduit. They indicate that the sudden explosions were due to the ascent of several magma batches that were slowed during ascent and were not able to reach the surface. Changes in the rheology of the lava are linked to the influx of several batches of magma with different compositions as well as to compaction by gas loss when ascending andesitic magma pushed out overlying more viscous degassed magma clearing the conduit, which can explain why these sudden explosions were more energetic. Several geophysical data sets as well as tephra compositions were integrated to support this conclusion. The correlated multiparameters also confirm that geomagnetic volcano monitoring has been essential in understanding the processes that drive the observed changes in eruptive behavior. We present new evidence for the detection of transient events produced by magma ascent and changes in the feeding system of Popocatépetl volcano with wavelet analysis. Detailed vulcanomagnetic processing, especially when it is correlated with other monitoring parameters, provides information on ascending magma and several conduit processes that would otherwise be camouflaged. Ascending batches may precede an eruption but they can also ascend in several pulses indicating how dome growth occurs.
从喷出活动到爆炸活动的过渡会增加危险,因此确定磁信号变化等早期指标至关重要。自 1996 年以来,波波卡特佩特火山(墨西哥)经历了 80 多个火山口圆顶挤压和破坏周期后,其行为在 2019 年 3 月 15 日至 7 月 18 日期间发生了变化,当时没有观察到熔岩圆顶。一些圆顶表现为火山口底部包含熔岩流(薄饼),而另一些圆顶则呈不规则形状。为了研究 3 月和 6 月从喷出行为向爆炸行为过渡的原因,我们分析了波波卡特佩特火山磁监测网络在 2018 年 10 月至 2019 年 12 月期间的时间序列。根据从地磁场总强度值中剔除非局部变化的方法,对原始信号进行了加权差分(WD)分析,并使用离散-时间连续小波变换来评估时间序列中的局部能量变化。高能量时段(与负磁异常相关)是由与导管内运动相关的岩浆上升引起的。它们表明,突然爆炸是由于几批岩浆在上升过程中速度减慢,无法到达地表。熔岩流变学的变化与几批不同成分的岩浆涌入有关,也与上升的安山岩岩浆挤出上覆的粘度较高的脱气岩浆清理导管时气体流失造成的压实有关,这可以解释为什么这些突然爆炸的能量更大。对几组地球物理数据以及热灰岩成分进行了整合,以支持这一结论。相关的多参数还证实,地磁火山监测对于理解所观察到的火山爆发行为变化的驱动过程至关重要。我们提出了利用小波分析检测波波卡特佩特尔火山岩浆上升和馈源系统变化所产生的瞬态事件的新证据。详细的火山磁处理,尤其是与其他监测参数相关联时,可提供有关岩浆上升和若干导管过程的信息,否则这些信息将被掩盖。岩浆成批上升可能发生在火山爆发之前,但也可能分几次上升,这表明了穹顶的增长过程。
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引用次数: 0
Quantitative analysis of crustal deformation, seismic strain, and stress estimation in Iran via earthquake mechanisms 通过地震机制对伊朗地壳变形、地震应变和应力估算进行定量分析
IF 2.9 3区 地球科学 Q3 GEOSCIENCES, MULTIDISCIPLINARY Pub Date : 2024-06-20 DOI: 10.3389/feart.2024.1408873
Majid Nemati, Ahmad Rashidi, Maryam Ezati, Reza Derakhshani
This study investigates the variations in stress, strain, and deformation of the Earth’s crust in Iran arising from tectonic movements and seismic activities. We employed the Kostrov and Molnar methods to quantify these parameters, focusing on the influence of different zoning techniques on the estimations. Analyzing data from 637 earthquakes (moment magnitudes &gt; 5.5) spanning 1909 to 2016, we determined the directions of maximum pressure, tension, and seismic strain through two primary approaches: comprehensive zoning and individual earthquake analysis. Additionally, we assess horizontal shortening and vertical crustal adjustments. Our methodology involves three distinct strategies: individual earthquake analysis, 1° × 1° zoning, and tectonic zoning. The findings demonstrate that the choice of zoning method significantly affects the direction and magnitude of seismic strain estimations. Although both methods identified significant deformations in the Dasht Bayaz and Qaen regions of Eastern Iran, differences between the Kostrov and Molnar methods in estimating seismic strain are observed. The high Zagros region shows signs of crustal thickening, whereas the Zagros foreland exhibits crustal thinning. Intriguingly, Eastern Alborz indicates uplift, and Western Alborz suggests subsidence, offering an alternative view to the conventional tectonic understanding of the Alborz range. These results highlight the critical role of zoning in stress analyses and the disparities between widely used estimation techniques. They underscore the necessity of careful method selection and interpretation in geodynamic studies, particularly in seismically active regions like Iran.
本研究调查了伊朗地壳因构造运动和地震活动而产生的应力、应变和变形变化。我们采用 Kostrov 和 Molnar 方法对这些参数进行量化,重点关注不同分区技术对估算结果的影响。我们分析了 1909 年至 2016 年期间 637 次地震(震级为 5.5 级)的数据,通过两种主要方法确定了最大压力、拉力和地震应变的方向:综合分区和单个地震分析。此外,我们还评估了水平缩短和垂直地壳调整。我们的方法包括三种不同的策略:单个地震分析、1° × 1°区划和构造区划。研究结果表明,区划方法的选择对地震应变估计的方向和幅度有很大影响。虽然两种方法都确定了伊朗东部 Dasht Bayaz 和 Qaen 地区的重大变形,但 Kostrov 和 Molnar 方法在估算地震应变方面存在差异。高扎格罗斯地区显示出地壳增厚的迹象,而扎格罗斯前陆则显示出地壳变薄的迹象。耐人寻味的是,东阿尔伯兹地区显示出隆起,而西阿尔伯兹地区则显示出下沉,这与阿尔伯兹山脉的传统构造认识不同。这些结果凸显了分区在应力分析中的关键作用,以及广泛使用的估算技术之间的差异。它们强调了在地球动力学研究中,特别是在伊朗这样的地震活跃地区,谨慎选择和解释方法的必要性。
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引用次数: 0
Seismically-induced permanent displacements of slopes using 3D Nested Newmark method 利用三维嵌套纽马克法计算地震诱发的斜坡永久位移
IF 2.9 3区 地球科学 Q3 GEOSCIENCES, MULTIDISCIPLINARY Pub Date : 2024-06-20 DOI: 10.3389/feart.2024.1355767
Qiang Li, Yan-Yang Tong, Jin-Nan Wang, Hui Xu
The Newmark method is a classic method for evaluating the permanent displacements of a slope under seismic loads. This study aims at proposing a three-dimensional nested Newmark method (3D-NNM) in the framework of the kinematic theorem of limit analysis. The classical three-dimensional rotational failure mechanism is discretized into a series of nested rotating wedges, each of which is subjected to a corresponding yield acceleration determined by employing the work rate balance, and each of which produces relative displacements under seismic excitations when it exceeds the yield acceleration. The total permanent displacement profile is further obtained by integration of the relative displacements from the slope toe to the slope crest. The obtained results show that the proposed 3D-NNM can effectively evaluate the permanent displacement profile of slopes under earthquakes, and the proposed 3D-NNM improves the Leshchinsky’s 2D nested Newmark method by 30.7%; the obtained total horizontal displacement at the slope middle height reduces with the number of nested blocks, but increases with the increasing of the slope-width-to-height ratios. Besides, the traditional Newmark method with a single sliding block tends to overestimate the permanent displacements of slope under seismic shakings.
纽马克法是评估地震荷载作用下斜坡永久位移的经典方法。本研究旨在极限分析运动学定理的框架内提出一种三维嵌套纽马克方法(3D-NNM)。经典的三维旋转破坏机制被离散化为一系列嵌套的旋转楔块,每个楔块都受到通过功速率平衡确定的相应屈服加速度的作用,每个楔块在地震激励下超过屈服加速度时都会产生相对位移。通过对从坡脚到坡顶的相对位移进行积分,进一步得到总的永久位移曲线。结果表明,所提出的三维-NNM 可以有效地评估地震作用下斜坡的永久位移剖面,而且所提出的三维-NNM 比 Leshchinsky 的二维嵌套 Newmark 方法提高了 30.7%;所得到的斜坡中间高处的总水平位移随嵌套块数的增加而减小,但随斜坡宽高比的增加而增大。此外,传统的单滑动块 Newmark 方法往往会高估地震震动下边坡的永久位移。
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引用次数: 0
Frontiers | Numerical simulation of groundwater in hyporheic zone with coupled parameter stochastic scheme 前沿 | 利用耦合参数随机方案对透水层地下水进行数值模拟
IF 2.9 3区 地球科学 Q3 GEOSCIENCES, MULTIDISCIPLINARY Pub Date : 2024-06-18 DOI: 10.3389/feart.2024.1426899
Jing Wang, Tianye Wang, Shougang Zhao, Ruidong Sun, Yan Lan, Yibo Zhang, Mengke Du, Taihe Zhang, Jinyu Wu, Quanfu Zhang
Groundwater numerical modeling is a crucial scientific tool for understanding groundwater circulation and supporting regional water resource planning and management. The effectiveness of these models depends largely on the accuracy of hydrogeological parameters within aquifers, which are often spatially heterogeneous and randomly distributed due to complex geological and tectonic factors. Traditional modeling approaches frequently overlook this randomness, compromising the precision and resolution of groundwater simulations. This study focuses on a section of the Qingshui River in the Huaihe River Basin. Using field and laboratory data, probability distribution functions for key parameters like hydraulic conductivity, specific yield, and specific storage were developed. These functions were integrated into the groundwater model to reflect the inherent stochastic nature of aquifer properties. This integration significantly enhanced model accuracy, reducing the root mean square error of simulated water levels from 0.47–1.43 m to 0.13–0.16 m and improving the Nash-Sutcliffe efficiency coefficients (NSE) from −2.96–0.73 to 0.94–0.98. Additionally, the model facilitated analysis of the interactions between river and groundwater, particularly in the hyporheic zone, under various scenarios. It identified spatial and temporal variations in groundwater recharge dynamics and delay effects at different distances from the river channel. For instance, recharge rates at 50 m and 150 m from the river were 0.295 m/day and 0.015 m/day, respectively, indicating stronger recharge closer to the river. The study also assessed the impact of varying river flows, riverbed permeability, and irrigation practices on water exchanges between the river and groundwater. These factors were found to significantly influence the intensity of water exchange, seepage, and groundwater reserves. This research provides valuable insights for managing river-groundwater interactions and analyzing the ecological environment of surrounding groundwater systems, underscoring the importance of incorporating stochastic characteristics into groundwater modeling.
地下水数值模型是了解地下水循环和支持区域水资源规划与管理的重要科学工具。这些模型的有效性在很大程度上取决于含水层内水文地质参数的准确性,而由于复杂的地质和构造因素,含水层内的水文地质参数往往在空间上是异构和随机分布的。传统的建模方法往往忽略了这种随机性,影响了地下水模拟的精度和分辨率。本研究以淮河流域清水河河段为研究对象。利用实地和实验室数据,开发了水力传导率、比产率和比储量等关键参数的概率分布函数。这些函数被集成到地下水模型中,以反映含水层固有的随机性质。这种整合大大提高了模型的精度,将模拟水位的均方根误差从 0.47-1.43 米降低到 0.13-0.16 米,并将纳什-苏特克利夫效率系数(NSE)从-2.96-0.73 提高到 0.94-0.98。此外,该模型还有助于分析在各种情况下河流与地下水之间的相互作用,特别是在地下水层。它确定了距河道不同距离的地下水补给动态和延迟效应的时空变化。例如,距河道 50 米和 150 米处的补给率分别为 0.295 米/天和 0.015 米/天,表明离河道较近的补给较强。研究还评估了不同的河流流量、河床渗透性和灌溉方式对河流与地下水之间水交换的影响。研究发现,这些因素对水量交换强度、渗流和地下水储量有重大影响。这项研究为管理河流与地下水之间的相互作用以及分析周围地下水系统的生态环境提供了宝贵的见解,强调了将随机特征纳入地下水模型的重要性。
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引用次数: 0
Frontiers | Geological and glaciological controls of 21,700 active methane seeps in the northern Norwegian Barents sea 挪威巴伦支海北部 21,700 个活跃甲烷渗漏点的地质和冰川学控制因素
IF 2.9 3区 地球科学 Q3 GEOSCIENCES, MULTIDISCIPLINARY Pub Date : 2024-06-17 DOI: 10.3389/feart.2024.1404027
Pavel Serov, Karin Andreassen, Monica Winsborrow, Rune Mattingsdal, Henry Patton
Due to tectonic uplift in the Cenozoic and numerous shelf-wide glaciations during the Quaternary, ∼1–2.5 km of sedimentary overburden has been eroded from the Barents Sea shelf, leading to the exhumation and partial uncapping of hydrocarbon accumulations. Widespread natural gas and oil leakage from the glacially eroded middle-upper Triassic reservoir directly into the water column has been documented at the Sentralbanken high in the northern Norwegian Barents Sea. However, it remains unclear whether the hydrocarbon leakage occurs only from the middle-upper Triassic reservoir units in geological settings exceptionally conducive to hydrocarbon leakage, or if other reservoir formations contributed to the release of hydrocarbons into the water column. It is also not clear whether complete erosion of the caprock is a prerequisite for widespread liberation of natural gas and oil from glacially eroded reservoirs across Arctic continental shelves. Here we analyze multibeam echosounder data covering ∼5,000 km2 and a suite of high-resolution P-cable seismic lines from a range of geological structures across the northern Norwegian Barents Sea. Our analyses reveal that ∼21,700 natural gas seeps originate from exhumed, faulted and variably eroded structural highs bearing a range of Mesozoic reservoir formations. All investigated structural highs fuel seabed methane release hotspots with no exception. Evident from observations of seismic anomalies, fluid accumulations are pervasive in the subsurface and likely to continue fuelling seabed gas seepage into the future. We also document that gas seepage through faults piercing overburden, caprocks and reaching potential reservoir levels is pervasive at all investigated structural highs. On the Storbanken high and the Kong Karl platform, such fault-controlled seepage is more prevalent than seepage from reservoir formations subcropping below the seafloor. Using a simple parametrization approach, we estimate that seeps identified within our multibeam data coverage produce a seabed methane flux of 61 x 107 mol/yr (9,803 ton/yr), which is one to two orders of magnitude higher than other globally known submarine methane seepage provinces. Fluxes of methane from sea water to the air above the thermogenic gas seep provinces in the northern Norwegian Barents Sea remain to be determined.
由于新生代的构造抬升和第四纪期间多次全陆架冰川作用,巴伦支海陆架上有1~2.5千米的沉积覆盖层被侵蚀,导致油气储层被挖出并部分封顶。据记录,在挪威巴伦支海北部的 Sentralbanken 高地,天然气和石油从冰川侵蚀的三叠纪中上层储层直接广泛渗漏到水体中。然而,目前仍不清楚碳氢化合物泄漏是否仅发生在特别有利于碳氢化合物泄漏的地质环境中的三叠纪中上层储层单元,或者是否其他储层构造也导致碳氢化合物释放到水体中。此外,目前还不清楚盖岩的完全侵蚀是否是整个北极大陆架冰蚀储层天然气和石油广泛释放的先决条件。在此,我们分析了挪威巴伦支海北部一系列地质结构中覆盖面积达 5,000 平方公里的多波束回声测深仪数据和一套高分辨率 P 型电缆地震测线。我们的分析表明,21,700 个天然气渗漏源于出露、断层和不同侵蚀的构造高地,这些构造高地承载着一系列中生代储层。所有被调查的构造高地无一例外都是海底甲烷释放的热点。通过对地震异常现象的观察可以看出,地下普遍存在流体聚集现象,而且很可能在未来继续助长海底天然气的渗出。我们还记录到,在所有调查过的构造高地,天然气通过穿透覆盖层和盖岩的断层渗出并到达潜在储层的现象十分普遍。在斯托尔班根高地和孔卡尔平台上,这种由断层控制的渗流比海底下储层的渗流更为普遍。利用简单的参数化方法,我们估计在多波束数据覆盖范围内发现的渗流产生的海底甲烷通量为 61 x 107 摩尔/年(9,803 吨/年),比全球已知的其他海底甲烷渗流区高出一到两个数量级。挪威巴伦支海北部热成因气体渗漏区上方从海水到空气的甲烷通量仍有待确定。
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引用次数: 0
Frontiers | Landslide susceptibility mapping using multiple combination weighting determination: a case study of collector roads in Pingshan County, Hebei Province, China Frontiers | 使用多重组合加权法测定滑坡易发性:河北省平山县集镇道路案例研究
IF 2.9 3区 地球科学 Q3 GEOSCIENCES, MULTIDISCIPLINARY Pub Date : 2024-06-17 DOI: 10.3389/feart.2024.1403830
Hui Li, Kun Song, Xing Zhai, Mingjia Liang
The landslide susceptibility map estimates the quantitative relationship between known landslides and control factors, and it has been used for site selection of infrastructures and geo-disaster management. As landslides and rockfalls occur frequently in mountainous areas in Hebei Province, China, due to road construction, the managing government needs to evaluate the vulnerability of geo-disasters in the road slopes to avoid unfavorable site selection for subsequent road constructions. Some typical collector road slopes were used as the study area in Pingshan County, Hebei Province. By analyzing the landslide triggering factors, we determined classification criteria and proposed a comprehensive method for determining the weighting. The respective weighting was calculated by the AHP and CRITIC method, and the combination weighting was determined by the game theory method. The landslide susceptibility of collector roads was evaluated and mapped using the ArcGIS platform. The susceptibility map was validated using landslide field investigation. The validation results show the effectiveness of the susceptibility methods, given the good number of correctly classified landslides. The landslide susceptibility map could have a significant impact on reducing the vulnerability of infrastructure to landslides in Hebei Province, China.
滑坡易发性图估算了已知滑坡与控制因素之间的定量关系,已被用于基础设施选址和地质灾害管理。在中国河北省的山区,由于道路建设导致的滑坡和落石频繁发生,因此管理部门需要对道路边坡的地质灾害易发性进行评估,以避免对后续道路建设的选址造成不利影响。河北省平山县一些典型的集镇道路边坡被作为研究区域。通过对滑坡诱发因素的分析,我们确定了分类标准,并提出了确定权重的综合方法。分别采用 AHP 法和 CRITIC 法计算各自权重,采用博弈论方法确定组合权重。利用 ArcGIS 平台对集散道路的滑坡易发性进行了评估和绘图。通过滑坡实地调查对易滑坡地图进行了验证。验证结果表明,由于正确分类的滑坡数量较多,易感性方法非常有效。滑坡易发性地图可对降低中国河北省基础设施易受滑坡影响的程度产生重大影响。
{"title":"Frontiers | Landslide susceptibility mapping using multiple combination weighting determination: a case study of collector roads in Pingshan County, Hebei Province, China","authors":"Hui Li, Kun Song, Xing Zhai, Mingjia Liang","doi":"10.3389/feart.2024.1403830","DOIUrl":"https://doi.org/10.3389/feart.2024.1403830","url":null,"abstract":"The landslide susceptibility map estimates the quantitative relationship between known landslides and control factors, and it has been used for site selection of infrastructures and geo-disaster management. As landslides and rockfalls occur frequently in mountainous areas in Hebei Province, China, due to road construction, the managing government needs to evaluate the vulnerability of geo-disasters in the road slopes to avoid unfavorable site selection for subsequent road constructions. Some typical collector road slopes were used as the study area in Pingshan County, Hebei Province. By analyzing the landslide triggering factors, we determined classification criteria and proposed a comprehensive method for determining the weighting. The respective weighting was calculated by the AHP and CRITIC method, and the combination weighting was determined by the game theory method. The landslide susceptibility of collector roads was evaluated and mapped using the ArcGIS platform. The susceptibility map was validated using landslide field investigation. The validation results show the effectiveness of the susceptibility methods, given the good number of correctly classified landslides. The landslide susceptibility map could have a significant impact on reducing the vulnerability of infrastructure to landslides in Hebei Province, China.","PeriodicalId":12359,"journal":{"name":"Frontiers in Earth Science","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141572228","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Tracking the variability of the western Pacific warm pool heat content over 1980–2020 跟踪 1980-2020 年西太平洋暖池热含量的变化情况
IF 2.9 3区 地球科学 Q2 Earth and Planetary Sciences Pub Date : 2024-06-14 DOI: 10.3389/feart.2024.1377715
Liang Jin, Chunlei Liu, Ning Cao, Xiaoqing Liao, Yufeng Xue, Ruijuan Bao, Lingli Fan, Lingjing Zhu, Qianye Su, Ke Yang, Rong Zheng, Shujie Chang, Mei Liang
The western Pacific warm pool (WPWP) is a major thermal driver of atmospheric deep convection and global atmospheric circulation in the tropics, and changes in its ocean heat content (OHC) affect the local and global climates. Four state-of-the-art ocean reanalyses and one objective analysis were used to study the variations in the WPWP OHC, ocean heat content tendency (OHCT), and ocean heat transport (OHT). The variabilities of both the OHC and OHCT integrated from 0 to 300 m are consistent between the datasets and are closely related to the El-Niño southern oscillation cycle. The integrated OHC from 0 to 2000 m shows an overall increasing trend in the WPWP. The WPWP mainly gains heat from the eastern boundary and loses heat from the northern boundary. The heat transport through the eastern boundary of the WPWP is mainly facilitated by the westward flowing south and north equatorial currents as well as the equatorial countercurrent around the depth of the thermocline, whereas the OHT at the northern boundary is mainly driven by the western boundary current of the Pacific Ocean, which shows complex flow structures.
西太平洋暖池(WPWP)是热带地区大气深层对流和全球大气环流的主要热驱动力,其海洋热含量(OHC)的变化会影响当地和全球气候。我们利用四个最先进的海洋再分析和一个客观分析来研究 WPWP OHC、海洋热含量趋势(OHCT)和海洋热传输(OHT)的变化。数据集之间从 0 米到 300 米的综合 OHC 和 OHCT 变率是一致的,并且与厄尔尼诺南方涛动周期密切相关。从 0 到 2000 米的综合 OHC 显示,WPWP 总体呈上升趋势。WPWP主要从东部边界获得热量,从北部边界失去热量。通过西太平洋暖温带东边界的热量输送主要是由向西流动的南赤道流、北赤道流以及温跃层深度附近的赤道逆流所推动的,而北边界的 OHT 主要是由太平洋西边界流所推动的,其流动结构复杂。
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引用次数: 0
A coal bursting liability evaluation model based on fuzzy set theory and analysis of three influencing factors 基于模糊集理论的煤炭爆破责任评价模型及三个影响因素分析
IF 2.9 3区 地球科学 Q2 Earth and Planetary Sciences Pub Date : 2024-06-14 DOI: 10.3389/feart.2024.1378956
Chao Wang, Zijun Jin, Xiaofei Liu, Tuanhui Wang, Yu Liu, Shaoyuan Zhang, Qiwei Wang
The classification of coal bursting liability is of great significance for the prevention and control of rock burst. To address the shortcomings in existing bursting liability classification methods, a comprehensive evaluation model for bursting liability based on a combination of weighted-fuzzy set theory and three influencing factor analyses is proposed. The model selects four evaluation indicators: dynamic failure time (DT), elastic energy index (WET), bursting energy index (KE), and uniaxial compressive strength (RC). Two types of membership functions, trapezoidal fuzzy numbers (TFN) and Gaussian fuzzy numbers (GFN), are used to quantitatively describe the fuzziness between indicator levels. The Delphi method and a random forest feature identification method are combined to obtain a subjective and objective combined weighting, determining the optimal combination weight of the four indicators. Based on Zadeh operator (ZO), maximum-minimum operator (MMO), weighted-average operator (WAO), and all-around restrictive operator (ARO), calculations are carried out for the synthesis of indicator weights and memberships. Maximal membership principle (MMP) and Credible identification principle (CIP) are utilized as evaluation principle to assess the bursting liability level, constructing 16 fuzzy comprehensive evaluation models. The impact of membership functions, fuzzy operators, and evaluation principle on evaluation results are systematically analyzed based on the discrimination results of 127 sample sets. The results show that the optimal fuzzy comprehensive evaluation model is constructed using the trapezoidal fuzzy numbers, weighted average operator, and maximal membership principle (TFN-WAO-MMP), with a classification accuracy of 97.64%. Finally, the optimal model is applied to 10 engineering instances, and the evaluation results are consistent with the actual situation, verifying the reliability and effectiveness of the model. Overall, these findings contribute to the development of a more sophisticated and accurate method for assessing the rock burst tendency of coal specimens. By leveraging the theory of fuzzy sets, this approach provides a more nuanced and nuanced evaluation of rock burst tendency, and thus offers the potential to improve workplace safety and efficiency in the coal mining industry.
煤炭爆破责任划分对防治岩爆具有重要意义。针对现有爆破责任划分方法的不足,提出了基于加权模糊集理论和三个影响因素分析相结合的爆破责任综合评价模型。该模型选取了四个评价指标:动态破坏时间(DT)、弹性能量指数(WET)、爆破能量指数(KE)和单轴抗压强度(RC)。采用梯形模糊数(TFN)和高斯模糊数(GFN)两种成员函数来定量描述指标等级之间的模糊性。结合德尔菲法和随机森林特征识别法,得出主客观综合权重,确定四个指标的最优组合权重。基于 Zadeh 算子(ZO)、最大最小算子(MMO)、加权平均算子(WAO)和全方位限制算子(ARO),对指标权重和成员资格的合成进行计算。利用最大成员原则(MMP)和可信识别原则(CIP)作为评估爆破责任水平的评价原则,构建了 16 个模糊综合评价模型。根据 127 个样本集的判别结果,系统分析了成员函数、模糊算子和评价原则对评价结果的影响。结果表明,使用梯形模糊数、加权平均算子和最大成员原则(TFN-WAO-MMP)构建了最优模糊综合评价模型,分类准确率达到 97.64%。最后,将优化模型应用于 10 个工程实例,评价结果与实际情况相符,验证了模型的可靠性和有效性。总之,这些研究结果有助于开发一种更复杂、更准确的方法来评估煤炭试样的岩爆倾向。通过利用模糊集理论,该方法提供了一种更加细致入微的岩石爆裂倾向评估方法,从而为提高煤矿行业的工作场所安全和效率提供了可能。
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引用次数: 0
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