José Francisco da Cruz Neto , Francisco Charles dos Santos Silva , Carlos André Alves de Souza , Alexandre Maniçoba da Rosa Ferraz Jardim , Wilma Roberta dos Santos , Lady Daiane Costa de Sousa Martins , Wagner Martins dos Santos , Alan Mario Zuffo , Thieres George Freire da Silva
{"title":"Validation of a desertification monitoring model in a semiarid region with the support of machine learning techniques","authors":"José Francisco da Cruz Neto , Francisco Charles dos Santos Silva , Carlos André Alves de Souza , Alexandre Maniçoba da Rosa Ferraz Jardim , Wilma Roberta dos Santos , Lady Daiane Costa de Sousa Martins , Wagner Martins dos Santos , Alan Mario Zuffo , Thieres George Freire da Silva","doi":"10.1016/j.jsames.2025.105715","DOIUrl":"10.1016/j.jsames.2025.105715","url":null,"abstract":"<div><div>Desertification is a global and concerning phenomenon resulting from the interplay of climatic factors, inadequate human activities, and unsustainable use of natural resources. Its historical roots are linked to intensive agriculture, deforestation, and land-use changes, making the development of mathematical models crucial to sustainably identify and manage these areas. These models incorporate variables such as climatic patterns, land use, and degradation indicators, enabling an accurate assessment of the risk and extent of desertification in specific regions. The objective of this study was to evaluate the effectiveness of the RisDes_Index model in identifying areas affected by desertification and assessing the severity of environmental degradation. The model was developed based on orbital information and in situ data collected from Caatinga environments, wetlands, and areas undergoing desertification. The study was conducted in the Sertão Central region of Brazil, covering the municipalities of Floresta, Cabrobó, Belém do São Francisco, Carnaubeira da Penha, Itacuruba, and Orocó—an area known to be affected by desertification. The model demonstrated high efficacy in identifying desertified environments. One key feature that allows the RisDes_Index model to be applied to various global regions is its low computational power requirement, unlike machine learning and random forests, which, despite their high identification capacity, demand significant computational resources. However, the RisDes_Index model requires a higher operational capacity from researchers, which may render certain studies unfeasible due to a lack of necessary data. No correlations were found between the RisDes_Index model and vegetation indices (NDVI, SAVI, LAI, albedo, TGSI, and TSoil).</div></div>","PeriodicalId":50047,"journal":{"name":"Journal of South American Earth Sciences","volume":"165 ","pages":"Article 105715"},"PeriodicalIF":1.5,"publicationDate":"2025-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144757951","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}
Marcos Macchioli-Grande , Gimena Uran , Mariano Larrovere , Cecilia Echegoyen , María Poca
{"title":"Streamflow spatio-temporal variability of water stable isotopes and hydrochemical properties in a semiarid mountain catchment in Northwestern Argentina","authors":"Marcos Macchioli-Grande , Gimena Uran , Mariano Larrovere , Cecilia Echegoyen , María Poca","doi":"10.1016/j.jsames.2025.105717","DOIUrl":"10.1016/j.jsames.2025.105717","url":null,"abstract":"<div><div>Mountain catchments are critical sources of water. Particularly in semiarid regions, where precipitation is exceeded by potential evapotranspiration, mountain catchments are important water reservoirs for the population settled in the nearby lowlands. This study investigates the spatio-temporal variability of water stable isotopes and hydrochemical properties in the semiarid Huaco catchment, located in the Sierras Pampeanas of the Andean foreland in Northwestern Argentina. Stream water samples were collected across four sub-catchments along an altitudinal gradient. The results indicate that electrical conductivity and chloride concentrations increase downstream (from 148.1 to 307.2 μS cm<sup>−1</sup> for the former and from 17.7 to 46.4 ppm for the latter) while water stable isotopic composition (δ<sup>18</sup>O and δ<sup>2</sup>H) remain uniform across the altitudinal gradient (with averages of −5.1 ‰ and −24 ‰, respectively). These spatial variations are indicative of increasing evaporative concentration with decreasing altitude, also exhibiting decreasing streamflow with decreasing altitude. Moreover, water is diluted (with TDS up to 175 mg L<sup>−1</sup>), alkaline (pH = 8.2–8.5), and transitions from bicarbonate-mixed to bicarbonate-sodium types downstream. Within the year 2022, major ions showed slight seasonal variation. Conversely, water stable isotopes remained constant within the temporal scale. This suggests groundwater as a uniform source feeding streamflow. Additionally, concentration-streamflow relationships of electrical conductivity and chloride suggest predominantly chemostatic behavior, highlighting limited variability in solute concentrations despite changes in streamflow. This integrative isotopic, hydrochemical, and hydrometric approach provides insights into the hydrological dynamics in this semiarid mountain catchment, improving the understanding of hydrological processes in these environments.</div></div>","PeriodicalId":50047,"journal":{"name":"Journal of South American Earth Sciences","volume":"165 ","pages":"Article 105717"},"PeriodicalIF":1.5,"publicationDate":"2025-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144763970","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":"Microorganisms on siliceous-speleothems: example from sandstone caves, Brazil","authors":"Cintia Fernandes Stumpf , Matheus Denezine , Paola Ferreira Barbosa , Sérgio Leandro de Vieira Toledo , Beatriz Bachega Groppo , Tulio Gabriel Ramos Ribeiro","doi":"10.1016/j.jsames.2025.105711","DOIUrl":"10.1016/j.jsames.2025.105711","url":null,"abstract":"<div><div>This study investigates siliceous speleothems by characterizing their macro- and microscopic features in caves formed within the Botucatu Formation, Paraná basin, Brazil. The analyzed speleothems consist of aerial coralloids composed of amorphous opal and detrital quartz grains, with biological components such as microbial-like filaments and diatoms. Two centric diatoms morphotypes are reported: <em>Orthoseira</em> sp. and Gen. 1 sp.1 and also a possible pennate species. Whereas diatom assemblage is confined to the photic and twilight zones, microbial filaments are reported both within these zones in addition to environments with limited sunlight exposure. The presence of biofilms and diatoms may increase local pH, facilitating silica dissolution and reprecipitation processes that contribute to speleothem formation. These caves are cataloged as geosites within the Corumbataí Geopark project, a pioneering initiative aimed at becoming the first geopark in the São Paulo State. This research enhances the first report of microbial assemblage in association with siliceous speleothems from the Serra de Itaqueri caves in the São Paulo State. In addition, understanding the biochemical processes that influence the development of siliceous speleothems in quartzose lithologies is crucial for deciphering their genesis mechanisms and potential environmental implications. All these dynamics involved in these caves highlight its relevance as a strategic geosite for paleoenvironmental, ecological, and conservation studies.</div></div>","PeriodicalId":50047,"journal":{"name":"Journal of South American Earth Sciences","volume":"165 ","pages":"Article 105711"},"PeriodicalIF":1.7,"publicationDate":"2025-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144712868","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}
Alfredo E. Zurita , Carlos A. Luna , Francisco Cuadrelli , Daniel Barasoain , Ricardo H.A. Gómez , Omar Medina , Ángel R. Miño-Boilini
{"title":"New localities with Pleistocene mammals from the Department of Chuquisaca (Bolivia)","authors":"Alfredo E. Zurita , Carlos A. Luna , Francisco Cuadrelli , Daniel Barasoain , Ricardo H.A. Gómez , Omar Medina , Ángel R. Miño-Boilini","doi":"10.1016/j.jsames.2025.105691","DOIUrl":"10.1016/j.jsames.2025.105691","url":null,"abstract":"<div><div>Since the XIX century, the mammalian palaeofauna that inhabited the Pleistocene (ca. 2.6–0.0011 Ma) of South America is well known in several regions of this subcontinent, especially in the lowlands and at high latitudes. However, there is an imbalance in our knowledge of the diversity achieved by this palaeofauna, especially in the highlands of the current territory of Bolivia, known mainly from the Tarija Valley. With the aim of improving this situation, this paper presents and describes new fossil localities yielding Pleistocene mammals from the northern Department of Chuquisaca, in the Eastern Cordillera and Subandean geological provinces (ca. 2500<em>–</em>3500 m.a.s.l.). These localities include Sucre (S), Yampárez (Ya), Yotala (Yo), Redención Pampa (Rp), Potolo (P), Quila Quila (Q), Maragua (M), and Padilla (Pa), from which eight taxa have been identified: Xenarthra: <em>Panochthus</em> sp. (Rp, Ya), <em>Glyptodon jatunkhirkhi</em> (Yo, Rp), <em>Pampatherium</em> sp. (Rp), <em>Tolypeutes</em> cf. <em>T. matacus</em> (Rp), <em>Megatherium</em> sp. (P); Perissodactyla: <em>Equus</em> sp. (Yo, Rp, Q, M); Artiodactyla: <em>Lama guanicoe</em> (Rp); Proboscidea: <em>Cuvieronius hyodon</em> (Rp). The results show that so far <em>G. jatunkhirkhi</em> is endemic to the Eastern Cordillera and Subandean ranges, while it is reported the first Pleistocene record of <em>Tolypeutes</em> (Chlamyphoridae) for Bolivia, previously restricted to the Early Holocene, in addition to the first mandibular remains of <em>G. jatunkhirkhi</em>, which allows a better characterization of this species. Overall, the recognized assemblages suggest the presence of open and arid/semiarid environments, taking into account the presence of two living sensitive species, i.e. <em>Tolypeutes T.</em> cf. <em>matacus</em> and <em>L. guanicoe</em>. The large number of specimens recorded shows the high fossil potential of some localities in northern Chuquisaca.</div></div>","PeriodicalId":50047,"journal":{"name":"Journal of South American Earth Sciences","volume":"165 ","pages":"Article 105691"},"PeriodicalIF":1.7,"publicationDate":"2025-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144711788","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}
Vinicius Soares Campos, Tárcio Rocha Lopes , Mateus de Oliveira Macedo, Fernando Simões Santos, Joyce Alchapar Silva, João Paulo Francisco, Fabricio Leite
{"title":"Multicriteria geospatial analysis for prioritizing soil erosion risk areas in a reservoir-contributing watershed","authors":"Vinicius Soares Campos, Tárcio Rocha Lopes , Mateus de Oliveira Macedo, Fernando Simões Santos, Joyce Alchapar Silva, João Paulo Francisco, Fabricio Leite","doi":"10.1016/j.jsames.2025.105714","DOIUrl":"10.1016/j.jsames.2025.105714","url":null,"abstract":"<div><div>Soil erosion is a serious threat to sustainable land use management, making the identification of erosion-prone areas increasingly important. This study aimed to identify areas with riska to soil erosion in the Piquiri River basin, a significant tributary of the Paraná River and a key contributor to the Itaipu Hydroelectric Plant reservoir. A Multi-Criteria Analysis (MCA) integrated with geospatial techniques was used to map areas most susceptible to erosion. Several factors were considered: topography, land use and cover, soil erodibility, landslide susceptibility, proximity to rivers, time of concentration, and pasture quality. The criteria were analyzed using the Analytic Hierarchy Process (AHP), which allowed for weighting the relative importance of each factor based on expert consultation. The factors were combined using two multi-criteria methods: Weighted Linear Combination (WLC) and Ordered Weighted Averaging (OWA). The maps indicated that the highest erosion risk areas are mainly concentrated in the upper and middle parts of the basin, associated with steep slopes and degraded pastures. Furthermore, it was found that regions close to rivers also presented high priority for intervention. The OWA method, by varying the level of risk and compensation, made it possible to simulate different decision-making scenarios. The methods were compared with MUSLE and similarity was verified between the priority areas estimated by multicriteria analysis and soil loss. The study concludes that multicriteria techniques, integrated with geospatial tools, are effective in identifying priority areas for intervention, supporting soil conservation and erosion mitigation actions.</div></div>","PeriodicalId":50047,"journal":{"name":"Journal of South American Earth Sciences","volume":"165 ","pages":"Article 105714"},"PeriodicalIF":1.5,"publicationDate":"2025-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144720850","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}
Renato Francisco da Silva Souza , Vânia da Silva Fraga , Bruno de Oliveira Dias , Jhony Vendruscolo , Emanoel Lima Martins , Walter Esfrain Pereira , Victor Junior Lima Felix , Rodrigo Santana Macedo , Salomão de Sousa Medeiros , Milton Cesar Costa Campos
{"title":"Spatio-Temporal variability of CO2 efflux from stony soil under a seasonally dry tropical forest","authors":"Renato Francisco da Silva Souza , Vânia da Silva Fraga , Bruno de Oliveira Dias , Jhony Vendruscolo , Emanoel Lima Martins , Walter Esfrain Pereira , Victor Junior Lima Felix , Rodrigo Santana Macedo , Salomão de Sousa Medeiros , Milton Cesar Costa Campos","doi":"10.1016/j.jsames.2025.105712","DOIUrl":"10.1016/j.jsames.2025.105712","url":null,"abstract":"<div><div>Quantifying the variability of soil CO<sub>2</sub> efflux (SCE) in stony soils, such as the Leptosol of the Brazilian semi-arid region is essential to obtain accurate measurements of SCE and improve its global estimate. The objective of our study was to assess the temporal and spatial variability of the SCE in a Caatinga forest. The SCE was measured at 42 randomly selected sampling points in a 0.72 ha plot. The average SCE varied from 0.47 to 4.14 μmol of CO<sub>2</sub> m<sup>−2</sup> s<sup>−1</sup> in a dry and wet season, respectively. The temporal variability of SCE is explained by 93 % volumetric soil water content, while soil temperature explained 52 % independently. The non-linear relationship between volumetric soil water content and soil temperature explains 87 % of the variability. The autocorrelation spatial distance of SCE oscillated from 5.7 to 64.3 m and was smaller during the wet season. The spatial variability of SCE is related to SOC, C:N, pH, clay, volumetric soil water content, and soil temperature, but the type of relationship differs with season. The temporal variability of SCE is mainly controlled by the volumetric soil water content. To quantify SCE, a distance between points greater than 64.3 m must be adopted for the measurements to be considered statistically independent. Individually, soil attributes and environmental variables explain some SCE spatial variability, especially in the dry season. Landscape heterogeneity linked to rock fragments, Leptosols, and microtopography modulates SCE by altering moisture, temperature, and organic matter. Given the complexity of these interactions, future studies should account for such variability in Caatinga stony soils.</div></div>","PeriodicalId":50047,"journal":{"name":"Journal of South American Earth Sciences","volume":"165 ","pages":"Article 105712"},"PeriodicalIF":1.5,"publicationDate":"2025-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144749196","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}
João P.G. Machado , Rachel Motta Kurtz , Fernando A.S. Fernandez
{"title":"Big chill is hard to kill but it is time to move on - A comment on Faria et al., “3,500 years BP: The last survival of the mammal megafauna in the Americas”","authors":"João P.G. Machado , Rachel Motta Kurtz , Fernando A.S. Fernandez","doi":"10.1016/j.jsames.2025.105709","DOIUrl":"10.1016/j.jsames.2025.105709","url":null,"abstract":"","PeriodicalId":50047,"journal":{"name":"Journal of South American Earth Sciences","volume":"165 ","pages":"Article 105709"},"PeriodicalIF":1.7,"publicationDate":"2025-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144711789","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":"Geomorphological evidence of a historical Landslide-dammed Lake Outburst Flood in the Cajón del Bayo basin, Southern Central Andes (36°S)","authors":"Mariana Correas-Gonzalez , Stella M. Moreiras , Carolina Lauro , Pilar Jeanneret","doi":"10.1016/j.jsames.2025.105710","DOIUrl":"10.1016/j.jsames.2025.105710","url":null,"abstract":"<div><div>Landslide dammed lakes are created when mass movements block river valleys, posing potential hazards in the form of Landslide-dammed Lake Outburst Flood (LLOF). In the Southern Central Andes (SCA) of Argentina (36°S), a rock avalanche dammed the Cajón del Bayo basin in 1986, creating Baya Lake. This study reconstructs the historical evolution of the basin, focusing on key geomorphological changes including the rock avalanche, lake formation and subsequent outburst flood. The analysis included: a) a geomorphological mapping, identification of outburst flood deposits and remote sensing of landscape evolution; b) sedimentological description of landslide facies and lake-level variations; c) landslide-dam characterisation and stability assessment; and d) a hydrometeorological analysis of temperature and precipitation to contextualise the LLOF event. Results show that a 4.7 hm<sup>3</sup> rock avalanche impounded the Baya Lake. Geomorphic stability indices yielded contrasted results: while one classified the dam as stable, another indicated instability. Ultimately, the dam collapsed, triggering a LLOF that released 0.14 hm<sup>3</sup> of water from the lake and 0.3 hm<sup>3</sup> of sediments eroded from the dam, exposing its internal structure. Although geomorphic impacts were evident immediately downstream the lake, the event was not detected at the nearest gauging station, and a regional flood frequency analysis indicate low probability of occurrence of the empirically estimated peak discharge. This highlights how LLOFs occurred in remote areas may go unnoticed and how the increased discharge from small tributaries, though significant locally, can be attenuated in larger rivers. These findings underscore the importance of identifying and studying LLOFs at both local and regional scales in the SCA, where such events are underreported and may differ from global cases.</div></div>","PeriodicalId":50047,"journal":{"name":"Journal of South American Earth Sciences","volume":"165 ","pages":"Article 105710"},"PeriodicalIF":1.5,"publicationDate":"2025-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144724101","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}
Sebastián Oriolo , Emiliano M. Renda , Carlos A. Ballivián Justiniano , Sebastián Vázquez Lucero , Paulo Marcos , Rodrigo Suárez , María Belén Yoya , Pablo D. González
{"title":"More than 100 years of research on the origin of Patagonia","authors":"Sebastián Oriolo , Emiliano M. Renda , Carlos A. Ballivián Justiniano , Sebastián Vázquez Lucero , Paulo Marcos , Rodrigo Suárez , María Belén Yoya , Pablo D. González","doi":"10.1016/j.jsames.2025.105708","DOIUrl":"10.1016/j.jsames.2025.105708","url":null,"abstract":"<div><div>This work traces the historical development of ideas concerning the origin of Patagonia, considering alternative models and interpretations, and a discussion on the tectonic significance of the North Patagonian and Deseado massifs during the Paleozoic. Evidence indicates a common Paleozoic tectonomagmatic and metamorphic evolution for both the North Patagonian and Deseado massifs, which achieved their present-day configuration as the result of mainly Cenozoic tectonomagmatic processes that triggered uplift. On the other hand, these crustal domains were likely part of a rather large continental block, together with the Antarctic Peninsula, the Malvinas/Falkland Plateau, and the Maurice Ewing Bank, which was part of the western Kalahari Craton prior to Brasiliano–Pan-African collisions. Therefore, the late collision of the Kalahari Craton with the already amalgamated Western Gondwana was the most likely trigger of the juxtaposition of these African domains along the southern margin of the Río de la Plata Craton.</div></div>","PeriodicalId":50047,"journal":{"name":"Journal of South American Earth Sciences","volume":"165 ","pages":"Article 105708"},"PeriodicalIF":1.7,"publicationDate":"2025-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144695014","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 flood modeling using hydrograph and Rain-on-Grid approaches with HEC-HMS and HEC-RAS: A case study of the Culiacán River","authors":"Wenseslao Plata-Rocha , Evangelina Avila-Aceves , Sergio Alberto Monjardin-Armenta , Lidia Yadira Pérez-Aguilar , Jesús Gabriel Rangel-Peraza , Yedid Guadalupe Zambrano-Medina","doi":"10.1016/j.jsames.2025.105694","DOIUrl":"10.1016/j.jsames.2025.105694","url":null,"abstract":"<div><div>Floods are devastating natural disasters, causing extensive economic losses and fatalities globally each year. In developing regions, flood modeling is often hindered by limited or inconsistent hydrometeorological data and historical records. Accurate floodplain modeling is essential for assessing flood risks and identifying vulnerable areas. Combining hydrological and hydraulic models with GIS has become a key approach for simulating and analyzing flood events, particularly in ungauged watersheds. Traditionally, flood simulation is a two-step process where a hydrological model provides flow input for a separate hydraulic model. Modern approaches, such as 'Rain-on-Grid', use a single and integrated step: rainfall is applied directly to a 2D hydraulic model's grid, which handles both runoff generation and the routing of water through the landscape, channels, and streets. This study models urban flooding by integrating a 'Rain-on-Grid' approach for surface runoff with a hydrograph, derived from SCS and Snyder methods, to simulate the river flow. Model performance was assessed against gauging station data. For the SCS model, results showed R<sup>2</sup> values of 0.927, NSE of 0.678, RMSE of 2.1, and PBIAS of 12.06 for the SCS model; the Snyder model presented an R<sup>2</sup> of 0.865, NSE of 0.75, RMSE equal to 2.3, and PBIAS of 23.84, indicating comparable performance. Hydraulic simulation was evaluated using the fraction of model performance (F<sup>(2)</sup>), with values of 0.7101 (SCS) and 0.7108 (Snyder). Hazard mapping identified rivers, irrigation canals, drains, levees, and road crossings as high-risk zones. Additionally, intermittent streams present significant flood hazards due to rapid onset and high flow velocities, posing threats to vehicles and residents.</div></div>","PeriodicalId":50047,"journal":{"name":"Journal of South American Earth Sciences","volume":"165 ","pages":"Article 105694"},"PeriodicalIF":1.7,"publicationDate":"2025-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144665737","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}