Acta Geophysica最新文献

{"title":"Deep structure of the Tatra Mountains border faults (Western Carpathians): insights from magnetotellurics and gravimetry","authors":"Lenka Ondrášová,&nbsp;Vladimír Bezák,&nbsp;Ján Vozár,&nbsp;Radek Klanica,&nbsp;Svetlana Kováčiková,&nbsp;Pavol Zahorec,&nbsp;Graham Hill","doi":"10.1007/s11600-026-01993-3","DOIUrl":"10.1007/s11600-026-01993-3","url":null,"abstract":"<div><p>The knowledge of geological structures and mainly tectonic dislocations (faults) affects various areas of problems (seismic risks, slope deformations, radon emanation and others) and provides important information about the tectonic development of the studied area. The multidisciplinary research of geophysical and structural parameters has been carried out within the framework of the DISLOCAT project, with a focus on the Western Carpathians. This work focuses on refining the position and deep course morphology of the faults that delineate the Neogene horst of the Tatry Mountains, utilizing the magnetotelluric (MT) method and gravimetric map analysis. MT measurements with subsequent 3D modelling were carried out in three areas to image the faults structures in the western, central, and eastern parts of Tatry Mountains. In all sections through the 3D MT models and in the density models, the principal Tatry Fault, which bounds the Tatry Mountains from the South and SE, was identified in its current form as steep, or gently dipping to the south, suggesting that it is a normal fault. The slight displacement of the fault's position into the Tatry massif in its eastern part, relative to its location on geological maps, is likely caused by inaccuracies due to the overlaying fluvioglacial Quaternary sediments. The NE continuation of this fault appears unclear, and it seems to be truncated by EW trending faults that are indicated in the north part of the Tatry Mountains. These faults emerge between the cover and Mesozoic nappe units. Another parallel EW fault was identified north of the massif in the Paleogene fill.</p></div>","PeriodicalId":6988,"journal":{"name":"Acta Geophysica","volume":"74 5","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148987157","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Deep structure of the Tatra Mountains border faults (Western Carpathians): insights from magnetotellurics and gravimetry","authors":"Lenka Ondrášová,&nbsp;Vladimír Bezák,&nbsp;Ján Vozár,&nbsp;Radek Klanica,&nbsp;Svetlana Kováčiková,&nbsp;Pavol Zahorec,&nbsp;Graham Hill","doi":"10.1007/s11600-026-01993-3","DOIUrl":"10.1007/s11600-026-01993-3","url":null,"abstract":"<div><p>The knowledge of geological structures and mainly tectonic dislocations (faults) affects various areas of problems (seismic risks, slope deformations, radon emanation and others) and provides important information about the tectonic development of the studied area. The multidisciplinary research of geophysical and structural parameters has been carried out within the framework of the DISLOCAT project, with a focus on the Western Carpathians. This work focuses on refining the position and deep course morphology of the faults that delineate the Neogene horst of the Tatry Mountains, utilizing the magnetotelluric (MT) method and gravimetric map analysis. MT measurements with subsequent 3D modelling were carried out in three areas to image the faults structures in the western, central, and eastern parts of Tatry Mountains. In all sections through the 3D MT models and in the density models, the principal Tatry Fault, which bounds the Tatry Mountains from the South and SE, was identified in its current form as steep, or gently dipping to the south, suggesting that it is a normal fault. The slight displacement of the fault's position into the Tatry massif in its eastern part, relative to its location on geological maps, is likely caused by inaccuracies due to the overlaying fluvioglacial Quaternary sediments. The NE continuation of this fault appears unclear, and it seems to be truncated by EW trending faults that are indicated in the north part of the Tatry Mountains. These faults emerge between the cover and Mesozoic nappe units. Another parallel EW fault was identified north of the massif in the Paleogene fill.</p></div>","PeriodicalId":6988,"journal":{"name":"Acta Geophysica","volume":"74 5","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148986525","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geospatial mapping and modeling of groundwater recharge potential zones in elevated drought prone region of Bangladesh using analytical hierarchy process and GIS","authors":"Md. Nahid Hassan,&nbsp;Monirul Islam,&nbsp;Md. Ibrahim Adham,&nbsp;Chowdhury Sarwar Jahan,&nbsp;Quamrul Hasan Mazumder","doi":"10.1007/s11600-026-02026-9","DOIUrl":"10.1007/s11600-026-02026-9","url":null,"abstract":"<div><p>Accelerating groundwater depletion in the drought-prone Barind Tract of northwestern Bangladesh, driven by intensive irrigation demand and limited natural recharge, poses a critical threat to long-term water security. This study delineates groundwater recharge potential zones (GWRPZs) across the elevated Pleistocene terrace region by integrating GIS, remote sensing, and the Analytical Hierarchy Process with 14 hydrogeological and geospatial conditioning parameters, including geomorphology, land use/land cover, surface geology, inundation land type, soil texture, drainage density, slope, rainfall, top clay thickness, lineament density, TWI, TRI, TPI, and curvature. A key data-integration contribution is the explicit incorporation of borehole-derived top clay thickness as an independently weighted thematic layer, supplemented by vertical electrical sounding based resistivity interpretation and hydrostratigraphic profiling. Expert-informed pairwise comparisons (with CR = 0.06) and weighted overlay analysis in ArcGIS 10.8 produced a spatially continuous GWRPZ map classified into five zones: high (0.32%), fair (10.48%), moderate (31.61%), low (44.33%), and very low (13.26%). Low to very low recharge dominates the central uplands, where a thick Pleistocene clay aquitard (from 12.30 to 53.90 m), clay-rich soils, and elevated terrace morphology restrict vertical infiltration. Favorable recharge conditions are confined to northeastern and peripheral floodplain zones. Model validation using linear regression (<i>R</i>² = 0.70), ROC-AUC analysis (AUC = 0.751; 95% of CI: 0.665–0.813), and Monte Carlo simulation against 44 years of groundwater level records from 21 permanent hydrograph stations confirmed reliable predictive performance. The findings provide a scientific basis for targeting managed aquifer recharge interventions and support national water governance aligned with SDG 2, SDG 6, and SDG 13.</p></div>","PeriodicalId":6988,"journal":{"name":"Acta Geophysica","volume":"74 5","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148986162","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geospatial mapping and modeling of groundwater recharge potential zones in elevated drought prone region of Bangladesh using analytical hierarchy process and GIS","authors":"Md. Nahid Hassan,&nbsp;Monirul Islam,&nbsp;Md. Ibrahim Adham,&nbsp;Chowdhury Sarwar Jahan,&nbsp;Quamrul Hasan Mazumder","doi":"10.1007/s11600-026-02026-9","DOIUrl":"10.1007/s11600-026-02026-9","url":null,"abstract":"<div><p>Accelerating groundwater depletion in the drought-prone Barind Tract of northwestern Bangladesh, driven by intensive irrigation demand and limited natural recharge, poses a critical threat to long-term water security. This study delineates groundwater recharge potential zones (GWRPZs) across the elevated Pleistocene terrace region by integrating GIS, remote sensing, and the Analytical Hierarchy Process with 14 hydrogeological and geospatial conditioning parameters, including geomorphology, land use/land cover, surface geology, inundation land type, soil texture, drainage density, slope, rainfall, top clay thickness, lineament density, TWI, TRI, TPI, and curvature. A key data-integration contribution is the explicit incorporation of borehole-derived top clay thickness as an independently weighted thematic layer, supplemented by vertical electrical sounding based resistivity interpretation and hydrostratigraphic profiling. Expert-informed pairwise comparisons (with CR = 0.06) and weighted overlay analysis in ArcGIS 10.8 produced a spatially continuous GWRPZ map classified into five zones: high (0.32%), fair (10.48%), moderate (31.61%), low (44.33%), and very low (13.26%). Low to very low recharge dominates the central uplands, where a thick Pleistocene clay aquitard (from 12.30 to 53.90 m), clay-rich soils, and elevated terrace morphology restrict vertical infiltration. Favorable recharge conditions are confined to northeastern and peripheral floodplain zones. Model validation using linear regression (<i>R</i>² = 0.70), ROC-AUC analysis (AUC = 0.751; 95% of CI: 0.665–0.813), and Monte Carlo simulation against 44 years of groundwater level records from 21 permanent hydrograph stations confirmed reliable predictive performance. The findings provide a scientific basis for targeting managed aquifer recharge interventions and support national water governance aligned with SDG 2, SDG 6, and SDG 13.</p></div>","PeriodicalId":6988,"journal":{"name":"Acta Geophysica","volume":"74 5","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148986159","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spatial distribution law analysis of geological disasters induced by the “25·7” extreme rainfall in the Beijing–Tianjin–Hebei region","authors":"Haoran Dong,&nbsp;Chong Xu,&nbsp;Tao Li,&nbsp;Shuzhong Sheng,&nbsp;Xiaoyi Shao,&nbsp;Huiran Gao,&nbsp;Saier Wu,&nbsp;Su Yuan,&nbsp;Yunfei Tian,&nbsp;Yahao Wang,&nbsp;Jiale Jin","doi":"10.1007/s11600-026-02021-0","DOIUrl":"10.1007/s11600-026-02021-0","url":null,"abstract":"<div><p>In July 2025, the Beijing–Tianjin–Hebei region was hit by an unprecedented extreme torrential rain, which triggered extensive clustered geological disasters. To reveal the spatial distribution pattern and dominant controlling factors of regional landslides induced by this extreme rainfall, this study establishes a landslide inventory database based on remote sensing interpretation and field investigations. On this basis, GIS spatial analysis is integrated with the random forest model to quantitatively assess the contribution of nine predisposing factors to landslide occurrence. The results show that a total of 15,308 landslides were triggered by the extreme rainstorm, exhibiting an obvious spatially clustered distribution pattern. High-landslide-susceptibility areas are mainly concentrated in zones with cumulative rainfall of 250–300 mm, elevation of 400–600 m, slope gradient of 10–15°, concave slope morphology, and areas close to river valleys. Factor importance analysis further indicates that cumulative rainfall acts as the primary dominant factor, while elevation, lithology, and slope gradient serve as critical synergistic controlling factors. This study clarifies the unique formation mechanism of extreme rainfall-induced landslides in the semiarid region of North China and can provide a scientific reference for meteorological early warning of regional geological disasters as well as disaster prevention and mitigation decision-making.</p></div>","PeriodicalId":6988,"journal":{"name":"Acta Geophysica","volume":"74 5","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148986208","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spatial distribution law analysis of geological disasters induced by the “25·7” extreme rainfall in the Beijing–Tianjin–Hebei region","authors":"Haoran Dong,&nbsp;Chong Xu,&nbsp;Tao Li,&nbsp;Shuzhong Sheng,&nbsp;Xiaoyi Shao,&nbsp;Huiran Gao,&nbsp;Saier Wu,&nbsp;Su Yuan,&nbsp;Yunfei Tian,&nbsp;Yahao Wang,&nbsp;Jiale Jin","doi":"10.1007/s11600-026-02021-0","DOIUrl":"10.1007/s11600-026-02021-0","url":null,"abstract":"<div><p>In July 2025, the Beijing–Tianjin–Hebei region was hit by an unprecedented extreme torrential rain, which triggered extensive clustered geological disasters. To reveal the spatial distribution pattern and dominant controlling factors of regional landslides induced by this extreme rainfall, this study establishes a landslide inventory database based on remote sensing interpretation and field investigations. On this basis, GIS spatial analysis is integrated with the random forest model to quantitatively assess the contribution of nine predisposing factors to landslide occurrence. The results show that a total of 15,308 landslides were triggered by the extreme rainstorm, exhibiting an obvious spatially clustered distribution pattern. High-landslide-susceptibility areas are mainly concentrated in zones with cumulative rainfall of 250–300 mm, elevation of 400–600 m, slope gradient of 10–15°, concave slope morphology, and areas close to river valleys. Factor importance analysis further indicates that cumulative rainfall acts as the primary dominant factor, while elevation, lithology, and slope gradient serve as critical synergistic controlling factors. This study clarifies the unique formation mechanism of extreme rainfall-induced landslides in the semiarid region of North China and can provide a scientific reference for meteorological early warning of regional geological disasters as well as disaster prevention and mitigation decision-making.</p></div>","PeriodicalId":6988,"journal":{"name":"Acta Geophysica","volume":"74 5","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148986158","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Urban India’s vulnerability to compound climate extremes: a dependence perspective","authors":"Sourab Desai,&nbsp;Degavath Vinod,&nbsp;Amai Mahesha","doi":"10.1007/s11600-026-02031-y","DOIUrl":"10.1007/s11600-026-02031-y","url":null,"abstract":"<div><p>Understanding compound extremes and their dependence is crucial for developing mitigation and adaptation strategies. Compound events are co-occurring extreme weather events that significantly impact the environment more than isolated events. Urban India is highly vulnerable to these events due to rapid urbanisation, pollution and global warming. Using India Meteorological Department (IMD) gridded precipitation and temperature data spanning 71 years from 1951 to 2021 across 40 urban locations, three combinations of coincident events were identified: compound dry–hot events (CDHEs), compound heat-wet events (CHWEs), and compound cold–wet events (CCWEs). These coincidental events were defined by attributing thresholds to climate variables. A bivariate copula analysis examines the joint probability and dependence structure of these events. The copula analysis shows a significant positive dependence on all three combinations across 40 locations. Hyderabad, Chennai, and Kolkata show significant positive dependence across all three combinations, highlighting the specific vulnerabilities of those locations. Urban areas in Western India, Central India, and Peninsular India show a significant positive dependence of CDHEs at 40% exceedance probability. Cities in North-West India, West Central India, and Eastern India are highly vulnerable to CHWEs with return periods as low as 2 years. North Lakhimpur, Imphal, and other cities in North-East India are significantly affected by CCWEs, although their frequencies are lower, with a mean probability of co-occurrence of 14%. These findings critically impact urban resilience and adaptation strategies in a changing climate. Identifying regional hotspots and the evolving nature of compound extremes underscores the need for tailored approaches to mitigate the risks posed by these events and enhance the resilience of urban communities in India.</p></div>","PeriodicalId":6988,"journal":{"name":"Acta Geophysica","volume":"74 5","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148986422","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Urban India’s vulnerability to compound climate extremes: a dependence perspective","authors":"Sourab Desai,&nbsp;Degavath Vinod,&nbsp;Amai Mahesha","doi":"10.1007/s11600-026-02031-y","DOIUrl":"10.1007/s11600-026-02031-y","url":null,"abstract":"<div><p>Understanding compound extremes and their dependence is crucial for developing mitigation and adaptation strategies. Compound events are co-occurring extreme weather events that significantly impact the environment more than isolated events. Urban India is highly vulnerable to these events due to rapid urbanisation, pollution and global warming. Using India Meteorological Department (IMD) gridded precipitation and temperature data spanning 71 years from 1951 to 2021 across 40 urban locations, three combinations of coincident events were identified: compound dry–hot events (CDHEs), compound heat-wet events (CHWEs), and compound cold–wet events (CCWEs). These coincidental events were defined by attributing thresholds to climate variables. A bivariate copula analysis examines the joint probability and dependence structure of these events. The copula analysis shows a significant positive dependence on all three combinations across 40 locations. Hyderabad, Chennai, and Kolkata show significant positive dependence across all three combinations, highlighting the specific vulnerabilities of those locations. Urban areas in Western India, Central India, and Peninsular India show a significant positive dependence of CDHEs at 40% exceedance probability. Cities in North-West India, West Central India, and Eastern India are highly vulnerable to CHWEs with return periods as low as 2 years. North Lakhimpur, Imphal, and other cities in North-East India are significantly affected by CCWEs, although their frequencies are lower, with a mean probability of co-occurrence of 14%. These findings critically impact urban resilience and adaptation strategies in a changing climate. Identifying regional hotspots and the evolving nature of compound extremes underscores the need for tailored approaches to mitigate the risks posed by these events and enhance the resilience of urban communities in India.</p></div>","PeriodicalId":6988,"journal":{"name":"Acta Geophysica","volume":"74 5","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148986421","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Change-point detection and trend magnitude estimation in long-term streamflow records of a transboundary river basin under climate change","authors":"Gülçin Tanas Savaş,&nbsp;Neşe Ertugay,&nbsp;Okan Mert Katipoğlu","doi":"10.1007/s11600-026-02023-y","DOIUrl":"10.1007/s11600-026-02023-y","url":null,"abstract":"<div><p>Global climate change is reshaping basin hydrology by altering precipitation timing, evaporative demand, runoff generation, and groundwater recharge, which makes long-term streamflow trend detection essential for sustainable water resources management and climate adaptation. In this study, monthly, seasonal, and annual streamflow trends from three gauging stations in the upper Euphrates basin (D21A001, E21A019, and E21A051) were evaluated using an integrated non-parametric framework that combines Mann–Kendall (MK), Spearman’s rank correlation (SRC), Sequential Mann–Kendall (SMK), innovative trend analysis (ITA), and ITA slope (ITAS). This multi-method design allowed consistent identification of trend direction, magnitude, and temporal transition behavior, while also improving interpretive robustness across stations with different streamflow characteristics. The results show a clear common signal: streamflow weakening is most pronounced in the spring to early summer period, although the strength and timing vary by station. E21A019 shows a relatively coherent declining trend across methods, particularly during April–June and at seasonal and annual scales, indicating a stronger tendency toward streamflow reduction compared to the other stations. E21A051 shows a seasonally contrasting regime, with increasing tendencies in winter and late summer/early autumn (notably January–February and August–September), but decreasing trends during spring and early summer, implying intra-annual redistribution rather than uniform change. D21A001 presents weaker trend magnitudes overall, yet decreasing tendencies are still evident in late spring, early summer, and autumn. Across methods, MK and SRC consistently support the trend directions, while ITA/ITAS better highlight magnitude and seasonal contrast. Overall, the findings provide robust evidence of long-term streamflow change and hydrological pressure in the upper Euphrates basin. They can support adaptive and transboundary water management planning, while attribution to specific climatic or anthropogenic drivers requires direct analysis of the relevant forcing variables.</p><h3>Graphical abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":6988,"journal":{"name":"Acta Geophysica","volume":"74 5","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148986276","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Change-point detection and trend magnitude estimation in long-term streamflow records of a transboundary river basin under climate change","authors":"Gülçin Tanas Savaş,&nbsp;Neşe Ertugay,&nbsp;Okan Mert Katipoğlu","doi":"10.1007/s11600-026-02023-y","DOIUrl":"10.1007/s11600-026-02023-y","url":null,"abstract":"<div><p>Global climate change is reshaping basin hydrology by altering precipitation timing, evaporative demand, runoff generation, and groundwater recharge, which makes long-term streamflow trend detection essential for sustainable water resources management and climate adaptation. In this study, monthly, seasonal, and annual streamflow trends from three gauging stations in the upper Euphrates basin (D21A001, E21A019, and E21A051) were evaluated using an integrated non-parametric framework that combines Mann–Kendall (MK), Spearman’s rank correlation (SRC), Sequential Mann–Kendall (SMK), innovative trend analysis (ITA), and ITA slope (ITAS). This multi-method design allowed consistent identification of trend direction, magnitude, and temporal transition behavior, while also improving interpretive robustness across stations with different streamflow characteristics. The results show a clear common signal: streamflow weakening is most pronounced in the spring to early summer period, although the strength and timing vary by station. E21A019 shows a relatively coherent declining trend across methods, particularly during April–June and at seasonal and annual scales, indicating a stronger tendency toward streamflow reduction compared to the other stations. E21A051 shows a seasonally contrasting regime, with increasing tendencies in winter and late summer/early autumn (notably January–February and August–September), but decreasing trends during spring and early summer, implying intra-annual redistribution rather than uniform change. D21A001 presents weaker trend magnitudes overall, yet decreasing tendencies are still evident in late spring, early summer, and autumn. Across methods, MK and SRC consistently support the trend directions, while ITA/ITAS better highlight magnitude and seasonal contrast. Overall, the findings provide robust evidence of long-term streamflow change and hydrological pressure in the upper Euphrates basin. They can support adaptive and transboundary water management planning, while attribution to specific climatic or anthropogenic drivers requires direct analysis of the relevant forcing variables.</p><h3>Graphical abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":6988,"journal":{"name":"Acta Geophysica","volume":"74 5","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148986327","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}