Geomorphology最新文献

{"title":"Step-pool morphology in ephemeral gullies on steep slopes of the Loess Plateau: comparisons with other linear erosion features","authors":"Wenqian Liang ,&nbsp;Ximeng Xu ,&nbsp;Fenli Zheng","doi":"10.1016/j.geomorph.2025.110007","DOIUrl":"10.1016/j.geomorph.2025.110007","url":null,"abstract":"<div><div>Step-pool morphology has a great impact on hydraulic resistance and energy dissipation, closely associated with channel stability. The occurrence of the maximum flow resistance condition suggests maximum channel stability, which has been widely found in linear erosion features including streams and rills. However, step-pool morphology in ephemeral gullies (EGs) on steep slopes remains unclear, compared with other linear erosion features. Thus, field investigation was conducted in the two EGs on steep slopes of the Chinese Loess Plateau. The <em>H</em>/<em>L</em> and (<em>H</em>/<em>L</em>)/<em>S</em> of 171 step-pools in the two EGs (64 % and 58 % slope gradients) were analyzed and compared with eight sets of literature data in other linear erosion features, where <em>H</em>, <em>L</em>, and <em>S</em> represent step height, step spacing, and channel slope gradient, respectively. The results demonstrated that the step-pool morphology in EG channels of the study area was controlled by <em>S</em>. Steeper channel slope led to larger step-pool instability. <em>H</em>/<em>L</em> increased with the <em>S</em>, ranging from 0.11 to 1.00. In the two EGs, the maximum flow resistance condition occurred in half of step-pools with (<em>H</em>/<em>L</em>)/<em>S</em> ranging from 1 to 2, while another half of step-pools had (<em>H</em>/<em>L</em>)/<em>S</em> below 1, indicating fewer stable arrangements, and were predominantly found at <em>S</em> larger than 0.4. By incorporating monitored data from EGs and literature data from other linear erosion features, the relationship between step-pool morphology and channel slope gradient was also identified. <em>H</em>/<em>L</em> increased linearly with <em>S</em>, while (<em>H</em>/<em>L</em>)/<em>S</em> decreased as <em>S</em> increased, following a power function. When <em>S</em> was between 0.068 and 0.448, the (<em>H</em>/<em>L</em>)/<em>S</em> fell into the range of 1 to 2, representing the occurrence of the maximum flow resistance condition. This study fills a gap in understanding step-pool morphology in EGs on steep slopes by comparing with other linear erosion features and underscores the critical role of channel slope gradient.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":"489 ","pages":"Article 110007"},"PeriodicalIF":3.1,"publicationDate":"2025-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145027065","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Torta domes as part of a new morphological and rheological classification based on the distribution of Quaternary domes in the Central Volcanic Zone of the Andes, northern Chile","authors":"Alexander Scheinost ,&nbsp;Gabriel Ureta ,&nbsp;Felipe Aguilera","doi":"10.1016/j.geomorph.2025.109997","DOIUrl":"10.1016/j.geomorph.2025.109997","url":null,"abstract":"<div><div>Northern Chile has numerous effusive monogenetic events, among those domes without a morphological or rheological classification. This study analyzes 44 Quaternary domes (0–2.58 Ma) in the Central Volcanic Zone of the Andes (CVZA) using 57 radioisotopic ages (K<img>Ar and Ar<img>Ar) and geochemical data to define their distribution and establish a morphological-rheological classification focusing on torta-type domes. We employed i) compilation of published data, ii) k-means multivariable analysis to identify distribution patterns, and iii) morphometric calculations using MORVOLC to obtain physical parameters. We identified three geographical clusters (GC1, GC2, GC3) and four age clusters (AC1, AC2, AC3, AC4). The first one, GC1 (18.07°-19.79°S) comprises 11 domes, predominantly andesitic, with their activity in the last 700 ka; GC2 (21.21°-23.83°S) includes 25 domes, mainly dacitic, across the entire Quaternary. Finally, GC3 (25.99°-27.11°S) contains eight domes with dacitic and rhyolitic compositions, across the entire Quaternary. The morphological analysis contrasted two classifications: i) based only on morphology, and ii) based on rheology and morphology. In this way, we obtained 27 low lava domes, 10 coulées, and 7 “tortas,” a subtype of low lava dome. Torta domes in northern Chile are restricted to 19.5°-22.5°S and the last ∼400 ka, exhibit specific morphometric characteristics (circular and flat-topped): yield strength (τ₀) between 2.1E+05 and 7.5E+05 Pa, height/radius (H/R) ratio of 0.14–0.27, a mean flank slope of 16.78 to 25.93°, and a pre-eruptive angle surface between 2.96 and 6.72°. The spatial distribution and composition of these domes are related to the geological setting in the area, such as the Altiplano-Puna Volcanic Complex (APVC), the Altiplano-Puna Magma Body (APMB), and local/regional fault systems. This detailed analysis enhances our understanding of Quaternary monogenetic volcanism in the CVZA, providing valuable insights into magmatic evolution, eruption dynamics, morphological structures, and potential volcanic hazards associated in the region. The proposed classification scheme for torta-type domes may be applicable to similar volcanic features worldwide with defined rheological and morphological parameters.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":"489 ","pages":"Article 109997"},"PeriodicalIF":3.1,"publicationDate":"2025-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145019637","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sand provenance boundary in the Mu Us Sandy Land of northern China","authors":"Maotong Li ,&nbsp;Junsheng Nie ,&nbsp;Haobo Zhang ,&nbsp;Katharina Pfaff ,&nbsp;Zengjie Zhang","doi":"10.1016/j.geomorph.2025.110005","DOIUrl":"10.1016/j.geomorph.2025.110005","url":null,"abstract":"<div><div>Desert dunes are often assumed to have uniform mineral compositions due to extensive mixing during lateral transport, which complicates provenance studies. The Mu Us Sandy Land in north-central China, near the East Asian summer monsoon precipitation boundary, experiences a wetter climate than most deserts. Climate wetting as a result of a warming climate, and the ‘Sand Control Project’ implemented by the Chinese government to decrease the lateral movement of sand dunes in this area provide an opportunity to study surface processes of sand production and transport. Previous studies using zircon U<img>Pb geochronology and heavy mineral composition indicate distinct sand sources for the Mu Us Sandy Land: local basement-derived middle Yellow River sediments and recycled dried-up lacustrine sediments for the eastern part, and northeastern Tibetan Plateau-derived upper Yellow River sediments for the western part. However, zircons and heavy minerals only represent trace amounts of the bulk mineralogy within a sand dune, so broader provenance analysis targeting common minerals is essential. We focus on the area near the proposed provenance difference boundary between the western and eastern Mu Us Sandy Land, using comprehensive sampling and provenance techniques to confirm distinct provenance characteristics and delineate the provenance boundary. Our findings reveal that sand from most of the Mu Us Sandy Land originated from the erosion of local basement by the middle Yellow River and recycled local dried-up lacustrine sediments, whereas the southwestern corner and the neighboring western-central Chinese Loess Plateau received sediments from the distal northeastern Tibetan Plateau.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":"490 ","pages":"Article 110005"},"PeriodicalIF":3.1,"publicationDate":"2025-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145097762","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Detection of cryptotephra in sedimentary profiles using reflectance spectroscopy","authors":"Henry T. Crawford ,&nbsp;Morris C.S. Chan ,&nbsp;Mitch K. D'Arcy ,&nbsp;Sam Woor ,&nbsp;Olav B. Lian","doi":"10.1016/j.geomorph.2025.110003","DOIUrl":"10.1016/j.geomorph.2025.110003","url":null,"abstract":"<div><div>Explosive volcanic eruptions often blanket landscapes with tephra deposits that, if found, serve as valuable geochronological markers for landforms and sedimentary archives. However, fine-grained tephra (ash) layers are commonly obscured and go undetected, especially when ash fallout from smaller or more distant eruptions is thin, or where tephra has been mixed into host sediments by post-depositional reworking. Detecting these invisible trace tephras, termed ‘cryptotephra’, can greatly expand the scope of tephrochronology in geomorphological and stratigraphic investigations. Here, we use reflectance spectroscopy to detect cryptotephra within sedimentary landforms in western Canada. We first experimentally determine the visible to short-wave infrared (VSWIR) reflectance patterns of field-derived tephra and host sediments from alluvial, glacial, paleosol, and aeolian deposits. These data are used to build a tephra-detection model based on key absorption features principally arising from hydrated, Fe-bearing glass shards in tephra. Sensitivity analyses indicate that cryptotephra concentrations as low as 16 wt% can be confidently distinguished from host sediments characteristic of many post-glacial landforms in western Canada. Tephra concentration profiles from two field outcrops at Abraham Lake, Alberta, reveal an otherwise-indistinguishable cryptotephra (17 wt%) from the Mount St. Helens Yn eruption, along with evidence of <em>syn</em>- and post-depositional mixing. To test reproducibility, we apply the model to a tephra-bearing alluvial fan in northwest Argentina, where we again detect reworked cryptotephra within an incised fan section. Our findings demonstrate that field-based reflectance spectroscopy can (i) rapidly screen for cryptotephra in sediments and landforms; (ii) quantify tephra abundance in mixed or reworked deposits; and (iii) facilitate more-detailed terrestrial tephrochronology than traditional approaches.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":"489 ","pages":"Article 110003"},"PeriodicalIF":3.1,"publicationDate":"2025-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145004870","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quantifying five decades of shoreline change in relation to river sediment supply along the Phu Yen Coast, Central Vietnam","authors":"Quang Hao Nguyen ,&nbsp;Le Thi Que ,&nbsp;Tran Quoc Viet ,&nbsp;Tien Dat Pham ,&nbsp;Vinh Ngoc Tran ,&nbsp;Nguyen Tien Giang ,&nbsp;Phong Nguyen Thanh ,&nbsp;Duong Tran Anh","doi":"10.1016/j.geomorph.2025.110004","DOIUrl":"10.1016/j.geomorph.2025.110004","url":null,"abstract":"<div><div>We examined the relationship between shoreline dynamics and significant changes in river sediment supply along the Phu Yen Coast, a typical coastal area in central Vietnam, over a 53-year period (1972–2024). Empirical Orthogonal Functions (EOFs) were applied to a demeaned dataset to identify significant modes of shoreline position changes extracted from high-quality Landsat satellite data. Overall, we identified two distinct phases of coastal evolution: (i) a relatively stable period (1972–2012) characterized by modest accretion (+1 m/yr); (ii) followed by a period of shoreline retreat (2012–2024) at a rate of −1 m/yr. Notably, areas within 3 km of the river mouth, the shoreline exhibited severe geomorphic instability with retreat rates reaching −20 m/yr. Long-term monitoring of riverine processes in the Ba River system, the region's largest fluvial system, indicates a dramatic 82 % decline in river sediment discharge, from 2.17 × 10⁶ ton/yr in 1979–2007 to 0.4 × 10⁶ ton/yr in 2008–2023. Our EOF analysis showed that the first four modes explain up to 73 % of the observed shoreline variability, with primary controlling factors including riverine sediment supply fluctuations and both longshore and cross-shore transport processes. Significantly, we observed a multi-year lag between the reduction in river sediment supply and subsequent shoreline retreat, highlighting the complex temporal dynamics of coastal sediment budgets in response to anthropogenic perturbations.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":"489 ","pages":"Article 110004"},"PeriodicalIF":3.1,"publicationDate":"2025-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145048892","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessment of soil erosion by water on agricultural slopes in Poland based on runoff plot measurements","authors":"Ewa Smolska ,&nbsp;Jolanta Święchowicz ,&nbsp;Jerzy Rejman ,&nbsp;Jan Rodzik ,&nbsp;Józef Szpikowski ,&nbsp;Krzysztof Stępniewski","doi":"10.1016/j.geomorph.2025.109995","DOIUrl":"10.1016/j.geomorph.2025.109995","url":null,"abstract":"<div><div>This paper presents soil erosion measurements that were conducted between 2007 and 2009 on runoff plots under bare fallow and typical crop cultivations (cereals, root crops) across five regions of Poland representing diverse climatic and soil conditions. The aim of the research was to estimate the water erosion in these regions using a standardized method (runoff plots) and empirically by determining key parameters of the (R)USLE model: rainfall erosivity (<em>R</em>-factor), soil erodibility (<em>K</em>-factor), and cover management (<em>C</em>-factor). Rainfall erosivity during the study period exhibited considerable variability. The most extreme erosive rainfall event was recorded in southern Poland (907 MJ mm ha⁻¹ h⁻¹, Łazy). Seasonal distribution and rainfall intensity reflected regional climatic conditions. The study showed that soil erosion by rainfall exceeded that resulting from snowmelt. The average runoff coefficient varied annually from 0.24 % (cereals, sandy soil) to 10.5 % (fallow, silt loam). The mean annual soil loss rate (<em>SLR</em>) from bare fallow plots ranged from 2.5 to 73 Mg ha⁻¹, the lowest on sandy soils and highest on silt loam. Under beet and potato cultivation, soil loss rate was approximately 40 % lower and over 90 % lower under cereal crops than in the bare fallow. Grass cover nearly completely prevented soil erosion. Across all study areas, the highest erosion occurred from May to June. Discrepancies between empirically derived equation parameters and those calculated using the (R)USLE model highlight the necessity for regional model validation. <em>SLR</em> obtained in the study areas, using direct measurements and the (R)USLE model, fall within the range of estimates projected for European conditions.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":"489 ","pages":"Article 109995"},"PeriodicalIF":3.1,"publicationDate":"2025-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145049482","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Landscape evolution on conical landforms with applications to drainage development on volcanoes","authors":"Daniel O'Hara ,&nbsp;Liran Goren ,&nbsp;Benjamin Campforts ,&nbsp;Roos M.J. van Wees ,&nbsp;María Cristina Zarazúa-Carbajal ,&nbsp;Matthieu Kervyn","doi":"10.1016/j.geomorph.2025.109998","DOIUrl":"10.1016/j.geomorph.2025.109998","url":null,"abstract":"<div><div>Volcanic edifices are subject to a range of constructional and degradational processes, from explosive eruptions and effusive lava emplacement, to fluvial incision, glacial carving, and mass wasting; acting over various spatial and temporal scales and shaping the edifice. Understanding how an edifice's morphology evolves to reflect the interdependency of these processes is still in its early stages, complicated by physical process laws that remain underdeveloped within volcanic regions. Numerical modeling provides a useful tool to analyze this evolution by generalizing many of the processes that exist on volcanoes and considering their overarching effects on morphology over 100–1000 kyr timescales. Yet, despite advancement in applying numerical models to quantify landscape evolution, a basic understanding of drainage development and evolution on conical landforms in general remains incomplete.</div><div>Using simplified landscape evolution modeling, we test the ability to recreate natural volcano morphology evolution broadly as a consequence of the competition between topographic growth, fluvial erosion, and soil creep on a conical landform. Conducting a suite of models for volcanic edifice evolution over a nondimensional parameter space and comparing numerical edifice landform and radial drainage basin morphology trends to nature, we find a significant degree of overlap. Furthermore, we perform a misfit analysis between nature and models to constrain best-fitting erosional parameters within our nondimensional framework. Finally, we explore the effect of edifice size on radial drainage development and discuss the effects of other processes on edifice morphology. Our results suggest that despite the intricacies of multiple spatiotemporally-varying processes that occur on volcanic edifices, natural edifice morphological evolution is consistent with generalized construction and erosion models. This work thus lays the foundation for more detailed studies to investigate volcano histories through numerical modeling of a volcano's morphology.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":"489 ","pages":"Article 109998"},"PeriodicalIF":3.1,"publicationDate":"2025-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145004871","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development of counterscarps by flexural toppling of schist in the Bedretto valley, Swiss Alps","authors":"Masahiro Chigira ,&nbsp;Satoru Kojima ,&nbsp;Li Fei ,&nbsp;Michel Jaboyedoff","doi":"10.1016/j.geomorph.2025.109999","DOIUrl":"10.1016/j.geomorph.2025.109999","url":null,"abstract":"<div><div>Counterscarps are typical topographic features of deep-seated gravitational slope deformation (DGSD) and are commonly made by flexural toppling. However, their internal structures and chronological development are not well understood. We investigated the geological structure and development of two large flexural topplings of mica schist on the southern side of the Bedretto Valley, Swiss Alps, via field surveys, topographic analysis, trenching, and 14C dating. The flexural topplings occur on ridges between the tributary valleys and extend to a depth of 200 m without inflections; their bases are planar and exposed along the sides of the tributary valleys and expose downslope above the major slope breaks that form the rim of a U-shaped valley and are presumably made during the Lateglacial, which suggests that these two flexural topplings started before or during the Lateglacial. Two trenches suggest that the counterscarps are made by preferential shearing along brittle tectonic faults and that the displacement occurred episodically and that the total displacement reached 30 m in dip separation of the faults. A displacement event between approximately 3400 and 3000 y BP was induced by earthquake shaking, which is strongly suggested by gouge injection into the overlying deformed sediments in the trough.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":"489 ","pages":"Article 109999"},"PeriodicalIF":3.1,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145049483","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Integrated sonar-drone geomorphological mapping of maar lakes: Insights into compound maar eruptive histories","authors":"Jaime A. Cavazos-Alvarez ,&nbsp;Gerardo Carrasco-Núñez ,&nbsp;Sergio Enrique Macías-Medrano ,&nbsp;Javier Mancera-Alejándrez ,&nbsp;Ray D. Valley","doi":"10.1016/j.geomorph.2025.110002","DOIUrl":"10.1016/j.geomorph.2025.110002","url":null,"abstract":"<div><div>Morphological analysis of maar volcanoes provides compelling evidence for understanding their geological evolution. Especially when their craters exhibit compound shapes resulting from multiple spatially shifting explosions throughout their eruptive histories. In such cases, the spatial relationship of the overlapping explosive footprints reveals the eruptive sequence. Moreover, after their eruptive origin, maar craters are exposed to sedimentary processes that modify their original shapes. A challenge in studying the morphology of maar volcanoes arises when they host volcanic lakes that obscure their inner-crater features. This study presents a morphological analysis of maar lakes with compound shapes through high-resolution Digital Elevation Models (DEMs) that integrate topographic and bathymetric data. Two Quaternary maar lakes located in the Serdán-Oriental basin (Mexico) were selected for this analysis: La Preciosa and Quechulac. Both depict pristine compound shapes with overlapping explosive footprints that record the migration of the eruptive loci during their eruptive history. Moreover, each maar has an unusual geological feature that cannot be explained without a comprehensive morphological analysis: In the case of La Preciosa, the northern half of its crater presents a step and pristine tephra ring that thins and disappears southwards, where only the pre-maar sequence is exposed. The Quechulac maar presents an irregularly shaped island made of tephra near the center of its lake. The origin and temporality of this island remain unclear, and its presence challenges the explosive nature of maar volcanoes, which tend to dig and deepen near the center of their craters. The morphological inspection based on the resulting DEMs led to insightful geological interpretations that explain these unusual geological features. In La Preciosa, the northern part of the present crater was formed by multiple explosions that migrated spatially in a trending west-to-east direction. In contrast, the southern part resulted from the gravitational collapse of the country rock, which was facilitated by an explosion-induced subrosion process. The Quechulac maar also records an east-to-west migration of the explosion loci. The latest explosions formed a nested crater rim in the west, from which the highest topography emerged as an island. This methodology, introduced for the first time in maar lakes, has potential applications in other lacustrine environments to enhance geological interpretations.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":"489 ","pages":"Article 110002"},"PeriodicalIF":3.1,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144933468","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The effect of flood 2020 on the morphological changes of the Sadij River, Southeastern of Iran","authors":"Naimeh Rahimi ,&nbsp;Somaiyeh Khaleghi ,&nbsp;Alireza Salehipour Milani","doi":"10.1016/j.geomorph.2025.109994","DOIUrl":"10.1016/j.geomorph.2025.109994","url":null,"abstract":"<div><div>River floods occur in the coastal plain of the Oman Sea every year. The flood on January 11, 2020 had the highest discharge recorded in the Jask hydrometric station that caused changes in Sadij River and floodplain in Iran. The aim of this research is to investigate the effect of this flood event on the lower part of the Sadij River. This is the first study has been conducted in relation to the impact of flooding on an ephemeral river morphology in the Iranian Coast of the Oman Sea. In this regard, the river channel was divided into four reaches (A, B, C, and D) based on the channel morphology. Then, the morphometric parameters of the river, central angle, curvature coefficient, River Network Change Index, as well as the pattern and the stream power were examined by comparing the Sentinel-2 satellite images before and after this flood. Also, the flood zoning was carried out using SMADA and HEC-RAS software in different flood return periods. The results showed that the average central angle and the average curvature coefficient were 85.61 and 1.42° for the four reaches before the flood and 77.72 and 1.22° for the post-flood period, respectively. Further, based on the River Network Change Index, the erosion was dominant process in the reaches A (2.35), B (1.27) and C (0.39) while deposition prevailed in the reach D (−0.08). The flood power of this flood was high and separating some of the meanders in reach B from the main river channel. Also, this flood with a return period of 100 years covers an area of 12,882.4 ha, which should be considered in planning and river management. Therefore, this study provides new insights into flood-induced morphological changes as well as flood zoning in semiarid ephemeral rivers that can be used for the future development plans and river restoration.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":"489 ","pages":"Article 109994"},"PeriodicalIF":3.1,"publicationDate":"2025-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144933467","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}