Physics and Chemistry of the Earth最新文献_第5页

Contamination risk assessment of shallow groundwater in Xi'an City's plain area based on groundwater vulnerability, pollution loading, and groundwater function value 基于地下水脆弱性、污染负荷和地下水功能值的西安市平原区浅层地下水污染风险评价

IF 4.1 3区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Physics and Chemistry of the Earth

Pub Date : 2026-02-01 Epub Date: 2026-01-09 DOI: 10.1016/j.pce.2026.104281

Yan Liu , Jialu Pang , Weiwei Hu , Zhifeng Jia , Jia Chen , Hao Liu , Rui Lei

Groundwater contamination risk assessment is essential for effective groundwater management. This study proposes a framework for quantifying groundwater contamination risk in the Plain of Xi'an, China, integrating pollution loading, vulnerability, and function value. Pollution loading was assessed based on pollutant toxicity, likelihood of release, and potential release quantity. The DRASTIC model was optimized to reflect differences in net recharge between urban impermeable areas and agricultural areas for vulnerability assessment. Function value assessment included both in situ and extractive values. By integrating groundwater vulnerability and pollution loading, the groundwater basic contamination risk was generated, which showed that areas with high basic contamination risk comprise about 2.80 % of the plain, predominantly in overlapping pollution source zones on floodplains and alluvial fans. These zones are characterized by high vulnerability, and the presence of high-load pollution sources exacerbates the risk of contamination. Groundwater quality affirms the reliability of the basic contamination risk assessment. To further assess the consequences of pollution, a value-weighted contamination risk map was generated by introducing groundwater function value. High value-weighted contamination risk areas account for approximately 0.60 % of the plain, concentrated in floodplain zones with both high basic risk and function value. These areas require prioritized pollution prevention and control measures. The findings help identify priority areas for risk management and control, providing critical support for groundwater protection.

地下水污染风险评价是地下水有效管理的基础。基于污染负荷、脆弱性和功能价值，提出了西安平原地下水污染风险量化框架。根据污染物的毒性、释放的可能性和潜在的释放量来评估污染负荷。对DRASTIC模型进行了优化，以反映城市不透水区和农业区的净补给差异，用于脆弱性评价。功能价值评估包括原位价值和提取价值。综合地下水脆弱性和污染负荷，得出地下水基本污染风险值，表明高基本污染风险区约占平原面积的2.80%，主要集中在洪泛平原和冲积扇的污染源叠加区。这些地区的特点是高脆弱性，高负荷污染源的存在加剧了污染的风险。地下水水质验证了基本污染风险评价的可靠性。为了进一步评估污染后果，引入地下水功能值，生成了价值加权污染风险图。高价值加权污染风险区约占平原面积的0.60%，主要集中在基本风险和功能价值均较高的洪泛平原地区。这些地区需要优先采取污染防治措施。研究结果有助于确定风险管理和控制的重点领域，为地下水保护提供关键支持。

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引用次数: 0

Understanding groundwater mineralization and controls source apportioning using multivariate statistics, modeling, and sensitivity analysis in the Eastern parts of Ghana 利用多元统计、建模和敏感性分析了解加纳东部地下水矿化和控制源分配

IF 4.1 3区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Physics and Chemistry of the Earth

Pub Date : 2026-02-01 Epub Date: 2026-01-14 DOI: 10.1016/j.pce.2026.104301

Mahamuda Abu, Musah Saeed Zango, Maxwell Anim-Gyampo

Groundwater chemistry has been continuously modified by natural and human activities, justifying the need for continuous evaluation of groundwater geochemistry. The hydrochemistry of groundwater in the southeastern parts of Ghana suggests highly evolved groundwater. However, the controlling factors of the hydrochemical modifications are not well constrained. Hence, to characterize the mineralization and factor-sensitive processes controlling the hydrochemical changes in the area, the study adopted factor analysis (FA), prediction modeling, sensitivity analysis (for the first time), and spatial mapping. The following: TDS, HCO₃⁻, K⁺, Na⁺, and F⁻ are found to be higher than their respective WHO standards in 81 %, 63 %, 44 %, 46 %, and 11 % of the area, respectively. These have an implication of poor taste, odor, and palatability (TDS), corrosiveness of plumbing materials (HCO₃⁻), hyperkalemia (K⁺), kidney and heart-related problems (Na⁺), and high F⁻ health-related issues. The ratio proxies and discriminant plots reveal dissolution of silicate and carbonate minerals as the main controlling processes of the groundwater mineralization. This was corroborated by 3 principal components (PCs) with 40.8 %, 14.5 %, and 10.4 % of variance for PCs 1, 2, and 3, respectively. The prediction model and sensitivity analysis indicated that SO₄²⁻ has a positive influence on TDS and HCO₃⁻. In contrast, HCO₃⁻ and Mg²⁺ have a reverse influence on TDS and HCO₃⁻, respectively. Also, K⁺ is controlled by Na⁺ and Na⁺ by K⁺ in the groundwater. Hot spots of TDS, HCO₃⁻, K⁺, Na⁺, and F⁻ are observed at Asuotwene, Tabibian, Koforidua, Asokore, Dome, and Amasaman.

由于自然和人类活动不断改变地下水化学性质，因此需要对地下水地球化学进行持续评价。加纳东南部地下水的水化学表明，这是一种高度演化的地下水。然而，水化学改性的控制因素并没有得到很好的约束。为此，采用因子分析（FA）、预测建模、敏感性分析（首次）和空间填图等方法，对控制该区水化学变化的矿化和因子敏感过程进行了表征。TDS、HCO3−、K+、Na+和F−分别有81%、63%、44%、46%和11%的地区高于WHO标准。这些问题包括味道、气味和适口性差（TDS）、管道材料的腐蚀性（HCO3−）、高钾血症（K+）、肾脏和心脏相关问题（Na+）以及高F−与健康相关的问题。比值指标和判别图显示，硅酸盐和碳酸盐矿物的溶蚀作用是地下水成矿作用的主要控制过程。这被3个主成分（PCs）证实，PCs 1、2和3的方差分别为40.8%、14.5%和10.4%。预测模型和敏感性分析表明，SO42−对TDS和HCO3−有正向影响。相反，HCO3−和Mg2+对TDS和HCO3−的影响相反。地下水中K+受Na+控制，Na+受K+控制。在Asuotwene、Tabibian、Koforidua、Asokore、Dome和Amasaman观测到TDS、HCO3−、K+、Na+和F−的热点。

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引用次数: 0

Forecasting the bottom hole closed pressure using time series analysis paradigms. A case study of the Mishrif reservoir at West Qurna oilfield, southern Iraq 利用时间序列分析范式预测井底关闭压力。以伊拉克南部West Qurna油田Mishrif油藏为例

IF 4.1 3区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Physics and Chemistry of the Earth

Pub Date : 2026-02-01 Epub Date: 2026-01-09 DOI: 10.1016/j.pce.2026.104283

Mustafa A. Abdulhasan, Amna M. Handhal, Alaa M. Al-Abadi

This study seeks to establish a reliable forecasting framework for Bottom-Hole Close Pressure (BHCP) in the Mishrif Formation of the West Qurna-1 oilfield, southern Iraq, through a comparative analysis of six time-series and machine learning models evaluated under realistic operational conditions. Monthly BHCP, production, and injection data spanning a 12-year period were analyzed using a combination of classical time-series models-including Autoregressive Integrated Moving Average (ARIMA), Seasonal ARIMA (SARIMA), and Seasonal ARIMA with Exogenous Variables (SARIMAX)–alongside advanced machine learning techniques, specifically Long Short-Term Memory (LSTM) neural networks and Extreme Gradient Boosting (XGBoost). Model performance was assessed using root mean square error (RMSE) and mean absolute error (MAE). The LSTM achieved the best predictive performance, followed closely by Holt–Winters and SARIMA. Although SARIMAX produced slightly higher errors, it offered superior interpretability by explicitly modeling BHCP as a function of injection and production rates. In contrast, XGBoost overfitted severely, producing excellent training accuracy but poor generalization. Using the best-performing models (LSTM and SARIMAX), BHCP forecasts were generated under three different operational conditions. Scenario forecasting from 2022 to 2030 showed that increasing production by 40–80 % leads to a progressive pressure decline, whereas increasing injection by 40–80 % results in measurable pressure recovery. Under constant operational conditions, SARIMAX predicts a stable BHCP trajectory fluctuating around 2700–2800 psi. These findings demonstrate that reservoir pressure in the Mishrif Formation is highly sensitive to the production–injection balance and underscore the effectiveness of SARIMAX as a robust forecasting tool for reservoir-management decision-making.

本研究旨在通过在实际操作条件下评估的六种时间序列和机器学习模型的比较分析，为伊拉克南部西部Qurna-1油田Mishrif地层的井底闭合压力（BHCP）建立可靠的预测框架。利用经典时间序列模型（包括自回归综合移动平均（ARIMA）、季节性ARIMA （SARIMA）和外生变量季节性ARIMA (SARIMAX)），结合先进的机器学习技术，特别是长短期记忆（LSTM）神经网络和极端梯度增强（XGBoost），对12年期间的每月BHCP、产量和注入数据进行了分析。采用均方根误差（RMSE）和平均绝对误差（MAE）对模型性能进行评估。LSTM的预测效果最好，紧随其后的是Holt-Winters和SARIMA。尽管SARIMAX的误差略高，但通过将BHCP明确建模为注入速率和生产速率的函数，提供了更好的可解释性。相比之下，XGBoost过拟合严重，训练精度很好，但泛化能力差。使用性能最好的模型（LSTM和SARIMAX），在三种不同的操作条件下生成了BHCP预测。从2022年到2030年的情景预测显示，产量增加40 - 80%会导致压力逐渐下降，而注入量增加40 - 80%则会带来可测量的压力恢复。在恒定的作业条件下，SARIMAX预测BHCP轨迹稳定在2700-2800 psi左右。这些发现表明，Mishrif地层的油藏压力对生产-注入平衡高度敏感，并强调了SARIMAX作为油藏管理决策的强大预测工具的有效性。

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引用次数: 0

A comparative study of developed rainfall intensity-duration-frequency curves for Ganjam District, Odisha, India 印度奥里萨邦甘贾姆地区降雨强度-持续时间-频率曲线的比较研究

IF 4.1 3区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Physics and Chemistry of the Earth

Pub Date : 2026-02-01 Epub Date: 2026-01-09 DOI: 10.1016/j.pce.2026.104284

Padminee Samal , Sandeep Samantaray , Prakash C. Swain , Hashem Shafik Shakir , Zaher Mundher Yaseen

Inadequate availability of hydrological data, such as rainfall and runoff patterns over regions like Ganjam district in Odisha state, India, makes it challenging for hydrologists to effectively plan, organize, and design water resources projects. Hence, there is need for the development of rainfall Intensity-Duration-Frequency (IDF) curves using specific empirical methods. To develop an empirical relationship for Ganjam, in the state of Odisha, daily rainfall data were collected from 22 raingauge stations for the period from 1995 to 2018. The intensity of rainfall values was designed for shorter durations for various return periods, including 2 years, 5 years, 10 years, 20 years, 50 years, 100 years, and 200 years. The representative IDF curves developed using the least squares method were compared with the IDF curves developed using Kothyari and Garde's method. The findings showed that, the IDF generated on a regional constant basis by Kothyari and Garde's equation underestimates the rainfall intensities for 2-year and 5-year return periods. An application of the findings was made to predict the runoff for a given set of rainfall derived from the IDF curves using SCS-Curve Number method. The graphs were developed using the IDF curves applicable for a region under consideration and using SCS-CN method and known as the Runoff Depth-Rainfall Frequency-Rainfall Duration curves. Hence, in areas, where data availability is limited, the created IDF relationship can be utilized to forecast rainfall and runoff depths for the purpose of planning, design and operation of various water resources projects.

水文数据的可用性不足，例如印度奥里萨邦甘贾姆区等地区的降雨和径流模式，使水文学家难以有效地规划、组织和设计水资源项目。因此，有必要利用具体的经验方法开发降雨强度-持续时间-频率（IDF）曲线。为了建立奥里萨邦甘贾姆的经验关系，从1995年至2018年期间从22个雨台站收集了日降雨量数据。在2年、5年、10年、20年、50年、100年和200年的不同回归期，降雨强度值设计为较短的持续时间。将最小二乘法得到的具有代表性的IDF曲线与Kothyari和Garde方法得到的IDF曲线进行了比较。研究结果表明，Kothyari和Garde公式在区域常数基础上产生的IDF低估了2年和5年回归期的降雨强度。将这些发现应用于利用scs -曲线数方法从IDF曲线中得到的一组给定降雨的径流预测。这些图表是使用适用于所考虑区域的IDF曲线并使用SCS-CN方法绘制的，称为径流深度-降雨频率-降雨持续时间曲线。因此，在数据有限的地区，可以利用所建立的IDF关系来预测降雨量和径流深度，以供各种水资源项目的规划、设计和运行。

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引用次数: 0

Investigating the planform dynamics and LULC changes with predictive insights in a Sub-Himalayan Transboundary River Basin, India 印度亚喜马拉雅跨界河流流域台地动力学和LULC变化的预测研究

IF 4.1 3区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Physics and Chemistry of the Earth

Pub Date : 2026-02-01 Epub Date: 2025-12-18 DOI: 10.1016/j.pce.2025.104261

Jiarul Alam , Deepak Kumar Mandal , Jahurul Mandal , Harekrishna Manna , Sanjoy Barman , Anoop Kumar Shukla

Rapid population growth and human activities have significantly altered planform dynamics in river basins worldwide. Land Use Land Cover (LULC) changes pose significant environmental challenges by impacting hydrological processes and the sustainable management of land and water resources. This study examined the planform and LULC changes in the Raidak River basin using the CA-Markov model and geospatial techniques. The modified normalized difference water index was applied to delineate land-water boundaries, while riverbank migration, accretion, and erosion were assessed from 1930 to 2024. LULC classification for the period 1973–2024 was conducted using supervised classification methods. The results revealed that river erosion-accretion influenced land area and the rapid growth of built-up and croplands with declining vegetation, swamps, and water bodies. During 1930–2024, the most massive area was eroded by 114.91 sq. Km, where the river bank migrated an average of 801.01 m and 936.89 m by Raidak I and Raidak II, respectively. During 1973–2024, areas under different land uses were mostly converted to built-up and agricultural areas. As compared to 2024, the cropland, sandbar, and built-up areas were expected to increase by 0.14, 11.55, and 7.39 %, respectively, while dense vegetation, open vegetation, swamp, and water bodies were predicted to shrink by 5.80, 7.07, 23.56, and 4.91 %, respectively, by 2034. These insights allow regional authorities to develop evidence-based policies for sustainable environmental management. Additionally, the projected LULC patterns can enhance hybrid models, enabling a comprehensive assessment of their impact on natural resources.

人口的快速增长和人类活动显著改变了世界各地河流流域的台地动态。土地利用和土地覆盖变化通过影响水文过程以及土地和水资源的可持续管理，构成了重大的环境挑战。本研究利用CA-Markov模型和地理空间技术研究了来达克河流域的平台和LULC变化。采用修正的归一化水差指数来划定陆地-水边界，并对1930 - 2024年的河岸迁移、加积和侵蚀进行了评估。采用监督分类方法对1973-2024年的LULC进行分类。结果表明，河流侵蚀增积影响了土地面积，影响了植被减少、沼泽和水体减少的建成区和耕地的快速增长。1930-2024年间，最大面积的侵蚀面积为114.91平方公里。Raidak I和Raidak II的平均河岸迁移量分别为801.01 m和936.89 m。在1973-2024年期间，不同土地利用方式下的区域大多转变为建成区和农业区。与2024年相比，到2034年，耕地、沙洲和建成区面积分别增加0.14%、11.55%和7.39%，而茂密植被、开阔植被、沼泽和水体面积分别减少5.80%、7.07、23.56%和4.91%。这些见解使地区当局能够制定以证据为基础的可持续环境管理政策。此外，预估的LULC模式可以增强混合模式，从而能够全面评估其对自然资源的影响。

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引用次数: 0

Robust monthly precipitation forecasts using VMD-decomposed hybrid LSSVM–BiLSTM model optimized by Harris Hawks algorithm 基于Harris Hawks算法优化的vmd分解混合LSSVM-BiLSTM模型的稳健月降水预报

IF 4.1 3区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Physics and Chemistry of the Earth

Pub Date : 2026-02-01 Epub Date: 2025-12-29 DOI: 10.1016/j.pce.2025.104257

Behnoush Farokhzadeh , Sepideh Choobeh , Rasool Imani

Accurate prediction of monthly precipitation is crucial for sustainable water resources management in climate-sensitive regions such as the Urmia Lake Basin, northwestern Iran. This study proposes an optimized hybrid forecasting framework integrating Variational Mode Decomposition (VMD), Least Squares Support Vector Machine (LSSVM), Bidirectional Long Short-Term Memory (BiLSTM) networks, and the Harris Hawks Optimization (HHO) algorithm. The normalized monthly precipitation series (1980–2024) was decomposed into five Intrinsic Mode Functions (IMFs) and a residual component using VMD. LSSVM was applied to model the high- and medium-frequency IMFs, while BiLSTM captured the long-term residual trend. The HHO algorithm was employed to optimize model hyperparameters, minimizing reconstruction and prediction errors. Model evaluation revealed outstanding predictive performance, with Nash–Sutcliffe Efficiency (NSE) exceeding 0.97 and Root Mean Square Error (RMSE) below 1.6 mm across both training and testing phases, and strong correlation between observed and simulated rainfall. Bootstrap-based uncertainty analysis confirmed the model's stability and reliability. The optimized hybrid model was further applied to project monthly precipitation for 2030–2050, indicating an approximate 7 % increase in mean annual rainfall relative to the historical average (1980–2024). These results demonstrate that the VMD–HHO–LSSVM–BiLSTM hybrid framework effectively captures nonlinear, nonstationary rainfall dynamics across multiple temporal scales and provides a robust tool for hydrological forecasting and adaptive water management in the Urmia Lake Basin.

月降水量的准确预测对于气候敏感地区（如伊朗西北部的乌尔米亚湖盆地）的可持续水资源管理至关重要。本文提出了一种结合变分模态分解（VMD）、最小二乘支持向量机（LSSVM）、双向长短期记忆（BiLSTM）网络和哈里斯鹰优化（HHO）算法的优化混合预测框架。将逐月降水序列（1980—2024）归一化，利用VMD分解为5个本征模态函数（IMFs）和1个残差分量。LSSVM用于高频和中频IMFs的建模，而BiLSTM捕获了长期残差趋势。采用HHO算法优化模型超参数，使重建和预测误差最小化。模型的预测效果非常好，在训练和测试阶段，Nash-Sutcliffe效率（NSE）均超过0.97，均方根误差（RMSE）均低于1.6 mm，且观测值与模拟值之间具有很强的相关性。基于bootstrap的不确定性分析验证了模型的稳定性和可靠性。将优化后的混合模型进一步应用于2030-2050年的月降水量预测，结果表明，相对于1980-2024年的历史平均值，年平均降雨量增加了约7%。这些结果表明，VMD-HHO-LSSVM-BiLSTM混合框架可以有效地捕获跨时间尺度的非线性、非平稳降雨动态，为乌尔米亚湖流域的水文预报和适应性水管理提供了强有力的工具。

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引用次数: 0

Integrated source apportionment, risk assessment, and probabilistic modeling of potentially toxic elements in soils from an undeveloped metallogenic region, northwest China 西北欠发达成矿区土壤中潜在有毒元素的综合来源分配、风险评估和概率模型

IF 4.1 3区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Physics and Chemistry of the Earth

Pub Date : 2026-02-01 Epub Date: 2026-01-08 DOI: 10.1016/j.pce.2026.104288

Qiong Han , Wenfeng Wang , Tongyang Zhao , Liuyuan Jin , Yangshuang Wang , Shiming Yang , Yunhui Zhang

While risk zones of potentially toxic elements (PTEs) are generally associated with intensive anthropogenic disturbances, undeveloped metallogenic regions (UMRs) feature naturally high PTE concentrations that have received limited scientific attention. To fill this gap, this study investigated the sources and quantified the contributions of PTEs in the soils of a UMR in Northwest China, while assessing their associated ecological-health risks. A total of 480 soil samples were collected for analysis. A multi-method framework combining geochemical baseline values (GBVs), Positive Matrix Factorization (PMF), integrated pollution indices, and probabilistic health risk modeling was established. The results revealed that Mercury (Hg) exhibited the highest exceedance rate (13.33 %) compared with other PTEs. PTEs were predominantly derived from natural sources: soil parent material (61.91 %), Pb enrichment (22.98 %), Cu mineralization (10.50 %), and hydrothermal processes (4.61 %), suggesting a primarily geogenic origin. Ecological risk assessment identified Hg as the main contributor to ecological risk. Overall, soil quality in the study area ranged from unpolluted to slightly polluted, with localized high-risk zones mainly distributed in the eastern region. Health risk assessment showed that chromium (Cr) and cobalt (Co) were the major contributors to non-carcinogenic risk, while Cr dominated the carcinogenic risk. Notably, 49.32 % of the samples posed unacceptable non-carcinogenic risks to children, 10.01 % and 0.90 % posed unacceptable carcinogenic risks to children and adults, respectively. These results highlighted that natural metallogenic processes alone could generate unacceptable risks to ecological systems and vulnerable populations. Based on these findings, long-term monitoring of Cr, Co, and Hg in soils near PTE-enriched areas is recommended to mitigate potential ecological and health threats. The study results can provide a scientific basis for the management of soil PTEs in high-background metallogenic regions worldwide.

虽然潜在有毒元素（PTE）的危险区通常与强烈的人为干扰有关，但未开发的成矿区（UMRs）具有天然的高PTE浓度，但受到的科学关注有限。为了填补这一空白，本研究调查了中国西北一个UMR土壤中pte的来源并量化了其贡献，同时评估了其相关的生态健康风险。共收集了480份土壤样本进行分析。建立了地球化学基线值（GBVs）、正矩阵分解（PMF）、综合污染指数和概率健康风险建模相结合的多方法框架。结果表明，汞（Hg）的超标率最高，为13.33%。pte主要来源于土壤母质（61.91%）、Pb富集（22.98%）、Cu矿化（10.50%）和热液作用（4.61%），以地成因为主。生态风险评价认为汞是生态风险的主要因素。总体而言，研究区土壤质量从未污染到轻度污染，局部高危区主要分布在东部地区。健康风险评价结果显示，铬（Cr）和钴（Co）是造成非致癌性风险的主要因素，而铬（Cr）是致癌风险的主要因素。值得注意的是，49.32%的样品对儿童具有不可接受的非致癌风险，10.01%和0.90%的样品对儿童和成人具有不可接受的致癌风险。这些结果表明，自然成矿过程本身可能对生态系统和脆弱人群产生不可接受的风险。基于这些发现，建议对pte富集地区附近土壤中的Cr、Co和Hg进行长期监测，以减轻潜在的生态和健康威胁。研究结果可为全球高背景成矿地区土壤pte的管理提供科学依据。

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引用次数: 0

Reconstructing seismic landslide spatial records in data-scarce Indian Himalayas: a polygon-based inventory and susceptibility assessment for the 1999 Chamoli earthquake 在数据稀缺的印度喜马拉雅地区重建地震滑坡空间记录：1999年Chamoli地震的多边形盘存和易感性评估

IF 4.1 3区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Physics and Chemistry of the Earth

Pub Date : 2026-02-01 Epub Date: 2025-12-17 DOI: 10.1016/j.pce.2025.104243

Shivani Joshi , Akshat Vashistha , Srikrishnan Siva Subramanian , Ali P. Yunus

The seismically active Himalayas are highly prone to secondary hazards such as earthquake-induced landslides (EIL), which pose serious risks to local populations and reshape mountainous terrains. However, spatial data on historic EIL events in India remain limited. This study presents the first polygon-based landslide inventory for the 1999 M_w 6.6 Chamoli earthquake in Uttarakhand, improving significantly upon earlier point-based datasets. A total of 73 landslides were identified and mapped across the Chamoli and Rudraprayag districts, with validations through field surveys and archival reports. The study employed the frequency ratio method for landslide susceptibility mapping and evaluated the influence of topographic, geological, land-use, and tectonic factors. Despite the 25-year gap since the event, the landslide inventory aligns well with global trends in landslide size and frequency, confirming its completeness. These findings highlight the significance of historical remote sensing for reconstructing past events, supporting seismic hazard assessment, landscape evolution studies, and disaster risk reduction.

地震活跃的喜马拉雅地区极易发生地震引发的山体滑坡（EIL）等次生灾害，这给当地居民带来了严重的风险，并重塑了山区地形。然而，印度历史上EIL事件的空间数据仍然有限。本研究提出了1999年北阿坎德邦6.6 Mw Chamoli地震的第一个基于多边形的滑坡清单，在早期基于点的数据集的基础上有了显着改进。在Chamoli和Rudraprayag地区共确定和绘制了73个滑坡，并通过实地调查和档案报告进行了验证。采用频率比法进行滑坡易感性填图，评价地形、地质、土地利用、构造等因素对滑坡易感性填图的影响。尽管距离该事件有25年的差距，但滑坡清单与滑坡规模和频率的全球趋势保持一致，证实了其完整性。这些发现强调了历史遥感在重建过去事件、支持地震危害评估、景观演变研究和减少灾害风险方面的重要性。

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引用次数: 0

Experiments and simulations of gas slippage effect on gas permeability and gas production in methane-hydrate-bearing montmorillonite sediments 含甲烷水合物蒙脱石沉积物气滑脱对渗透率和产气量影响的实验与模拟

IF 4.1 3区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Physics and Chemistry of the Earth

Pub Date : 2026-02-01 Epub Date: 2026-01-16 DOI: 10.1016/j.pce.2026.104309

Qingkai Gu , Zhaoran Wu , Guijing Li , Jianhua Geng

Gas flow in deep-sea natural gas hydrate reservoirs is significantly influenced by gas slippage, particularly in montmorillonite-rich clay sediments characterized by high porosity (>0.4), low permeability (<2.3 mD), and micro-nano scale pore spaces. Under these conditions, clay expansion markedly enhances the gas slippage effect. Therefore, this study selects montmorillonite sediments as the representative research medium. Understanding the gas slippage effect on permeability and production rate is crucial for gas hydrate exploitation. By fitting experimental data and eliminating the gas slippage effect on permeability, a relationship was derived between gas permeability and decomposed water content, effective stress, gas slippage effect, and porosity. A gas production model for methane-hydrate-bearing montmorillonite sediments was developed accounting for gas slippage effect. Numerical simulation results indicate that the change in gas permeability is not a linear decline during the depressurization decomposition of methane hydrates. Instead, there are periods where gas permeability increases or the rate of decline slows. The contributions of gas slippage compensation, effective stress, decomposed water, and the reduction in hydrate saturation to the changes in gas permeability were analyzed in details. The average gas production rates for each stage shows that gas slippage compensation enhances permeability and increases gas production.

深海天然气水合物储层中的气体流动受气体滑脱的影响较大，特别是在高孔隙度（0.4）、低渗透率（2.3 mD）、孔隙空间为微纳米尺度的富蒙脱石粘土沉积物中。在此条件下，粘土膨胀显著增强了气滑效应。因此，本研究选择蒙脱石沉积物作为代表性研究介质。了解气滑脱对渗透率和产量的影响对天然气水合物开发至关重要。通过拟合实验数据，剔除气滑脱效应对渗透率的影响，推导出气藏渗透率与分解含水量、有效应力、气滑脱效应、孔隙度之间的关系。建立了考虑气滑效应的含甲烷水合物蒙脱石沉积产气模型。数值模拟结果表明，在甲烷水合物减压分解过程中，渗透率的变化不是线性下降的。相反，有一些时期，气体渗透率增加或下降速度减慢。详细分析了气滑脱补偿、有效应力、分解水和水合物饱和度降低对渗透率变化的贡献。每一级的平均产气量表明，气滑补偿提高了渗透率，增加了产量。

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引用次数: 0

Spatial discrepancy of stable isotopes in river water and groundwater, eastern Qaidam Basin: Controlling factors and implications for hydrological cycle 柴达木盆地东部河流和地下水稳定同位素空间差异：水文循环的控制因素及意义

IF 4.1 3区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Physics and Chemistry of the Earth

Pub Date : 2026-02-01 Epub Date: 2025-12-23 DOI: 10.1016/j.pce.2025.104251

Nuan Yang , Xinming Song , Liang Guo , Shouchuan Zhang , Guangcai Wang

Stable isotope-based hydrological cycle is the most commonly employed approach for water resource management. Qaidam Basin is situated near the summer monsoon boundary and exhibits particular hydrological sensitivity to climate change. Investigating the spatial variations and controlling factors of hydrogen and oxygen isotopes in water bodies in the eastern margin of the Qaidam Basin is conducive to elucidate hydrological processes and response to climate change. Focusing on the Xiangride and Delingha areas, the study combined the stable isotopic analysis (δD, δ¹⁸O, d-excess) in river water and groundwater and water vapor transport trajectories modeling (HYSPLIT model) to identify water sources, river water-groundwater interaction, and moisture sources and transport trajectories. The Xiangride and Delingha areas exist both commonalities and distinctions in the hydrological cycle processes. The relationships among δD, δ¹⁸O, and d-excess suggest that river water and groundwater in two areas derive from atmospheric precipitation generated in the surrounding mountainous areas and experience semblable evaporation intensities. River water-groundwater interaction follow a consistent pattern: river water infiltrates and recharges groundwater in the piedmont zone, followed by groundwater discharges into river water in the fine-soil plain. The combination of d-excess analysis and HYSPLIT modeling reveals that the moisture sources generated precipitation in two regions are controlled by the Westerlies, while the Delingha area is further influenced by local recycled moisture from the plain area. The study results provide a critical scientific basis for managing regional river water and groundwater resources or even entire Qaidam Basin.

基于稳定同位素的水循环是水资源管理中最常用的方法。柴达木盆地位于夏季风边界附近，对气候变化具有特殊的水文敏感性。研究柴达木盆地东缘水体氢、氧同位素的空间变化及其控制因素，有助于阐明水文过程及其对气候变化的响应。以相日勒和德令哈地区为研究对象，采用稳定同位素分析（δD、δ18O、d-excess）和水汽输送轨迹模拟（HYSPLIT模型）相结合的方法，对流域水源、河流-地下水相互作用、水汽来源和输送轨迹进行了识别。相日勒和德令哈地区在水循环过程中既有共性又有差异性。δD、δ18O和d-excess之间的关系表明，两个地区的河流和地下水来源于周边山区的大气降水，蒸发强度相似。河流与地下水的相互作用遵循一致的模式：在山前地区，河流水渗透并补给地下水，然后在细土平原地区，地下水向河流中排放。结合d-excess分析和HYSPLIT模型分析发现，两区降水的水汽来源均受西风带控制，而德令哈地区则进一步受到平原地区局部再循环水汽的影响。研究结果为区域河流和地下水资源乃至整个柴达木盆地的管理提供了重要的科学依据。

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引用次数: 0