Physics and Chemistry of the Earth最新文献

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Hydrochemical characteristics, groundwater nitrate sources and potential health risks in a typical alluvial plain of northwest China
IF 3 3区 地球科学
Physics and Chemistry of the Earth Pub Date : 2025-03-12 DOI: 10.1016/j.pce.2025.103903
Hao Liang , Peiyue Li , Vetrimurugan Elumalai , Yan Tian , Xiaomei Kou
{"title":"Hydrochemical characteristics, groundwater nitrate sources and potential health risks in a typical alluvial plain of northwest China","authors":"Hao Liang ,&nbsp;Peiyue Li ,&nbsp;Vetrimurugan Elumalai ,&nbsp;Yan Tian ,&nbsp;Xiaomei Kou","doi":"10.1016/j.pce.2025.103903","DOIUrl":"10.1016/j.pce.2025.103903","url":null,"abstract":"<div><div>Due to anthropogenic pressures and the unpredictable impacts of climate change, groundwater quality issue has emerged as a critical concern. This study was carried out to investigate the evolving geochemical profile, identify the nitrate sources and transformation mechanisms, and assess the associated health hazards of phreatic groundwater in the Hua District, China. To achieve this goal, 65 and 37 phreatic water samples were collected in in October 2018 and March 2023, respectively, and analyzed for main water quality parameters and stable isotopes (δ<sup>18</sup>O-H<sub>2</sub>O, δ<sup>2</sup>H-H<sub>2</sub>O, δ<sup>15</sup>N-NO<sub>3</sub><sup>-</sup>, and δ<sup>18</sup>O-NO<sub>3</sub><sup>-</sup>). Piper diagram and ionic ratios were used for understanding the hydrochemical types and its evolution, stable isotopes were employed for tracing nitrate source, and human health risk assessment was also conducted to quantify the human health risk caused by exposure to groundwater NO<sub>3</sub><sup>−</sup>. The results showed that main ion composition of groundwater hydrochemistry is controlled by the rock weathering and dissolution of carbonates and sulfate minerals. The chemical types of groundwater present an evolution trend from SO<sub>4</sub>•Cl-Ca•Mg to HCO<sub>3</sub>-Ca•Mg. Severe nitrate pollution was detected particularly in the central and southern regions, with peak nitrate concentrations reaching 442 and 271 mg/L in 2018 and 2023, respectively. Nitrate sources include sewage, soil organic nitrogen, and fertilizers. A shift from single (M&amp;S) to multiple nitrate sources in groundwater was observed, with nitrification as the primary transformation process. The non-carcinogenic risks for children and adults declined from 0.245–3.455 to 0.039–2.586 and from 0.236–2.392 to 0.031–1.469, respectively, from 2018 to 2023. Additionally, these risky regions are shifting northward. Hence, individuals in the north-central part should heighten their vigilance towards groundwater quality to reduce the threats of nitrate pollution to human health.</div></div>","PeriodicalId":54616,"journal":{"name":"Physics and Chemistry of the Earth","volume":"139 ","pages":"Article 103903"},"PeriodicalIF":3.0,"publicationDate":"2025-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143629106","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Naturally occurring radionuclides and potentially toxic elements in mine waters from artisanal mining sites within Ife-Ilesha schist-belt in Nigeria
IF 3 3区 地球科学
Physics and Chemistry of the Earth Pub Date : 2025-03-12 DOI: 10.1016/j.pce.2025.103902
Matthew Omoniyi Isinkaye , Paulinah Oyindamola Fasanmi , Hamid Osman , Mayeen Uddin Khandaker
{"title":"Naturally occurring radionuclides and potentially toxic elements in mine waters from artisanal mining sites within Ife-Ilesha schist-belt in Nigeria","authors":"Matthew Omoniyi Isinkaye ,&nbsp;Paulinah Oyindamola Fasanmi ,&nbsp;Hamid Osman ,&nbsp;Mayeen Uddin Khandaker","doi":"10.1016/j.pce.2025.103902","DOIUrl":"10.1016/j.pce.2025.103902","url":null,"abstract":"<div><div>The Ife-Ilesha schist belt in southwest Nigeria is one of the most mineralized schist belts in Nigeria. Large amount of wastes are generated during mining processes and accumulate as tailings within the mining environment. These tailings, which contain high concentrations of natural radionuclides and potentially toxic elements, are washed into mining ponds in the mining environment. The water in these mining ponds is utilized by miners and populations around the mining sites, thereby causing serious negative health effects on humans and the environment. Water samples were collected from mining pits and waste water ponds in five gold mining sites and a kaolin mining site within the Ife-Ilesha schist belt. Activity concentrations of natural radionuclides (<sup>40</sup>K, <sup>238</sup>U, and <sup>232</sup>Th) and potential toxic elements (PTEs) have been measured using gamma and atomic absorption spectroscopies. The results show that average concentrations of <sup>40</sup>K, <sup>238</sup>U, and <sup>232</sup>Th in the mine waters are 217 ± 40, 10 ± 09 and 16 ± 02 Bq/kg, which are far higher than their permissible level in water. The average concentrations PTEs decrease according to the sequence; Zn &gt; Cr &gt; Cu &gt; Pb &gt; As &gt; Cd &gt; Ni. The concentrations of As, Cd and Cr, exceeded their respective limits in mine water. Based on the results of this research, it can be concluded that the mine waters pose significant radiological risks. The results of PTEs show potential risks to both humans and the environment from the mine waters.</div></div>","PeriodicalId":54616,"journal":{"name":"Physics and Chemistry of the Earth","volume":"139 ","pages":"Article 103902"},"PeriodicalIF":3.0,"publicationDate":"2025-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143629567","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Comparative analysis of evapotranspiration models for lake Urmia: Implications for water resource management in semi-arid regions
IF 3 3区 地球科学
Physics and Chemistry of the Earth Pub Date : 2025-03-12 DOI: 10.1016/j.pce.2025.103906
Jafar Chabokpour
{"title":"Comparative analysis of evapotranspiration models for lake Urmia: Implications for water resource management in semi-arid regions","authors":"Jafar Chabokpour","doi":"10.1016/j.pce.2025.103906","DOIUrl":"10.1016/j.pce.2025.103906","url":null,"abstract":"<div><div>This paper presents a detailed study of evapotranspiration estimation over the period of 1974–2017 in the Lake Urmia basin, Iran. Traditional empirical models like Penman-Monteith, Hargreaves-Samani, Priestley-Taylor, and Thornthwaite are compared in this study with some advanced soft computing techniques, including artificial neural networks, adaptive neuro-fuzzy inference systems, and support vector regression. The results show that the soft computing techniques always perform better, particularly ANN, in comparison to traditional models for both accuracy and adaptability over various climatic conditions. Among the traditional approaches, the Penman-Monteith model performs best. It also introduces a new ET model dimensionally consistent, developed through dimensional analysis, which works comparably to the Penman-Monteith model. This long-term trend analysis reveals a highly significant annual increase in ET of about 5.2 mm y<sup>−1</sup>, with a change point detected in the year 1995. The study further discusses the effect of land use changes on ET patterns, showing remarkable increases in agricultural and urban areas of about 23.7 % and 156.3 %, respectively, over the study period. Sensitivity analyses, in fact, show that accurate ET estimation is very important where temperature and solar radiation measurements are concerned. In this respect, different statistical techniques like wavelet analysis and principal component analysis will be used to create nuanced insight into ET dynamics within the Lake Urmia basin. Moreover, the paper investigates models' performance for differing climatic conditions and their ability to capture extreme ET events. In this respect, the comprehensive approach to and the intercomparison of ET processes in semi-arid regions presented in this study are very useful.</div></div>","PeriodicalId":54616,"journal":{"name":"Physics and Chemistry of the Earth","volume":"139 ","pages":"Article 103906"},"PeriodicalIF":3.0,"publicationDate":"2025-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143629514","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Characterization and potential use of Djiboutian clays: Adsorption studies for the removal of heavy metal from wastewater
IF 3 3区 地球科学
Physics and Chemistry of the Earth Pub Date : 2025-03-07 DOI: 10.1016/j.pce.2025.103898
Mohamed Osman Awaleh , Youssouf Djibril Soubaneh , Leila Farah Adawe , Alexandre Coulombe , Mohamed Abdillahi Robleh , Moussa Mahdi Ahmed , Nima Moussa Egueh , Omar Assowe Dabar , Mahamoud Ali Chirdon , Ibrahim Houssein Kadieh
{"title":"Characterization and potential use of Djiboutian clays: Adsorption studies for the removal of heavy metal from wastewater","authors":"Mohamed Osman Awaleh ,&nbsp;Youssouf Djibril Soubaneh ,&nbsp;Leila Farah Adawe ,&nbsp;Alexandre Coulombe ,&nbsp;Mohamed Abdillahi Robleh ,&nbsp;Moussa Mahdi Ahmed ,&nbsp;Nima Moussa Egueh ,&nbsp;Omar Assowe Dabar ,&nbsp;Mahamoud Ali Chirdon ,&nbsp;Ibrahim Houssein Kadieh","doi":"10.1016/j.pce.2025.103898","DOIUrl":"10.1016/j.pce.2025.103898","url":null,"abstract":"<div><div>The aim of this study was to evaluate the potential use of the two biggest clay deposits from the Djibouti region as raw material for wastewater treatment and for the production of ceramics. The present study is the first to investigate the kinetics, sorption isotherms, hysteresis of Cu and Cd on two clays from the East African Rift System (EARS). Djiboutian clays (DCs) were characterized by a rapid uptake of these heavy metals with an equilibrium time of 400 min and uptake ranging from 48.8% to 97.4% at high initial metal concentrations (15 mg L<sup>−1</sup>) in the medium. A high adsorption coefficient (k<sub>d</sub><sup>S</sup>) values, from 8.31 to 20.80 L g<sup>−1</sup>, were observed for Cu, indicating a strong affinity of this metal for both clays. The k<sub>d</sub><sup>S</sup> values for Cd (0.29–3.64 L g<sup>−1</sup>) were significantly lower, suggesting different interaction mechanisms. These results are consistent with the Freundlich constant (k<sub>f</sub>) values obtained for Cu (8.88–1.05 mg g<sup>−1</sup>(L·mg<sup>−1</sup>)<sup>1/<em>n</em></sup>) and Cd (0.80–1.05 mg g<sup>−1</sup>(L·mg<sup>−1</sup>)<sup>1/<em>n</em></sup>) sorption isotherms onto DCs clays. Furthermore, desorption process exhibited high hysteresis index (HI) values (2.18–2.33) for Cu, suggesting strong sequestration on both DCs. These sorption behaviors can be associated with the properties of both Djiboutian clays whose characterization revealed large specific surface areas (62.7–64.8 m3/g), high open porosity (44.4–51.2%), and the presence of organic matter and negatively charged clay minerals such as illite, which interact well with divalent metals. Characterization of both clays and the chemical data of DCs plotted on a ternary diagram (SiO<sub>2</sub> <sup>−</sup> Al<sub>2</sub>O<sub>3</sub>−other oxides) suggested that these clays can be applied as raw materials for structural ceramic products. The study underscores the potential of DCs for trapping Cu and Cd pollutants from wastewater and for producing Class BIIb ceramics<sup>.</sup></div></div>","PeriodicalId":54616,"journal":{"name":"Physics and Chemistry of the Earth","volume":"139 ","pages":"Article 103898"},"PeriodicalIF":3.0,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143621024","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Assessment of geothermal water environment using multi-influencing factor analysis method: A case study of Reshuiwei geothermal field
IF 3 3区 地球科学
Physics and Chemistry of the Earth Pub Date : 2025-03-05 DOI: 10.1016/j.pce.2025.103896
Weiwu Ma , Cheng Peng , Shams Forruque Ahmed , Chong Yang , Gang Liu
{"title":"Assessment of geothermal water environment using multi-influencing factor analysis method: A case study of Reshuiwei geothermal field","authors":"Weiwu Ma ,&nbsp;Cheng Peng ,&nbsp;Shams Forruque Ahmed ,&nbsp;Chong Yang ,&nbsp;Gang Liu","doi":"10.1016/j.pce.2025.103896","DOIUrl":"10.1016/j.pce.2025.103896","url":null,"abstract":"<div><div>Geothermal water environment assessment is crucial to the utilization. Reshuiwei geothermal field has more resources than others in Hunan province. However, existing methods has some problems such as complicated analysis, need much data and/or rely more on geographic information system (GIS). Due to research limitations, data is insufficient. Thus, using existing methods in this study is challenging. Therefore, we develop ‘multi-influencing factor analysis’ method to assess this geothermal water environment. The ‘multi-influencing factor’ including gas composition, physiochemical characteristics, variations of essential ions and indicators, corrosion and scaling possibilities of geothermal water. The methodology is: First, the original data are gathered by shallow drilling and gas sampling equipment. Second, data is initially analyzed by cooperative departments. Finally, using proposed method, we empirically evaluate the geothermal water environment by considering outcomes of 4 elements. Results show that gas of geothermal water is mainly composed of O<sub>2</sub> and N<sub>2</sub>. Small contents of H<sub>2</sub>S are spotted. Geothermal water is depleted in Mg<sup>2+</sup>, Cl<sup>−</sup>, enriched in Na<sup>+</sup>, <span><math><mrow><msubsup><mtext>HCO</mtext><mn>3</mn><mo>−</mo></msubsup></mrow></math></span>, SiO<sub>2</sub>. Special substances such as <span><math><mrow><msubsup><mtext>SiO</mtext><mn>3</mn><mrow><mn>2</mn><mo>−</mo></mrow></msubsup></mrow></math></span> and F<sup>−</sup> are also spotted. Due to potential negative impacts of O<sub>2</sub>, H<sub>2</sub>S, SiO<sub>2</sub>, <span><math><mrow><msubsup><mtext>SiO</mtext><mn>3</mn><mrow><mn>2</mn><mo>−</mo></mrow></msubsup></mrow></math></span> and F<sup>−</sup> on geothermal water environment, they must be considered in future. The main ions and indicators of geothermal water show stable variations. Geothermal water exhibits low corrosion, reduced scale formation and is less likely to develop calcium carbonate scale. The geothermal water environment is stable and less erosive, which is beneficial for utilization. Geothermal resource exploitation would benefit from the proposed approach and results.</div></div>","PeriodicalId":54616,"journal":{"name":"Physics and Chemistry of the Earth","volume":"139 ","pages":"Article 103896"},"PeriodicalIF":3.0,"publicationDate":"2025-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143580279","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Optimum design of diversion weirs with grey wolf optimization
IF 3 3区 地球科学
Physics and Chemistry of the Earth Pub Date : 2025-03-05 DOI: 10.1016/j.pce.2025.103899
Tulay Sugra Kucukerdem Ozturk, Kemal Saplıoğlu
{"title":"Optimum design of diversion weirs with grey wolf optimization","authors":"Tulay Sugra Kucukerdem Ozturk,&nbsp;Kemal Saplıoğlu","doi":"10.1016/j.pce.2025.103899","DOIUrl":"10.1016/j.pce.2025.103899","url":null,"abstract":"<div><div>Water structures known as diversion weirs are built to control water flow and raise water levels. There are two distinct goals for this investigation. Making a minimal cost structure profile is the first step. Finding the constraint functions that are significant in various scenarios is the second step. While performing optimization, it is necessary to provide all constraint functions. On the other hand, while a single constraint function takes a value close to the limit value, the others move towards a safer area. The research looks at the most significant constraint functions considering this circumstance. One of the meta-heuristic techniques, the Grey Wolf algorithm, was used for these two goals. 500 iterations and 100 Grey Wolves were utilized while all models were running. Furthermore, every scenario will be executed thirty times, and the mean and standard deviation of the outcomes will be analyzed to assess the models' dependability. Finally, an interface that users who do not know how to use the program can easily use was created, and it was turned into a simple application.</div></div>","PeriodicalId":54616,"journal":{"name":"Physics and Chemistry of the Earth","volume":"139 ","pages":"Article 103899"},"PeriodicalIF":3.0,"publicationDate":"2025-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143621023","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Innovative drought analysis via groundwater information
IF 3 3区 地球科学
Physics and Chemistry of the Earth Pub Date : 2025-03-05 DOI: 10.1016/j.pce.2025.103901
Veysi Kartal
{"title":"Innovative drought analysis via groundwater information","authors":"Veysi Kartal","doi":"10.1016/j.pce.2025.103901","DOIUrl":"10.1016/j.pce.2025.103901","url":null,"abstract":"<div><div>Drought hazard has complicated features related to climatic and spatio-temporal characteristics, making it challenging to accurately identify and track. Contemporary approaches to drought monitoring generally use standardized drought indices due to their practical utility. Despite the availability of a various array of drought indices, their application introduces complexities in data mining and decision-making processes, potentially resulting in confused outcomes. However, this research developed a new hybrid drought index Multivariate Cluster Ensemble Drought Evaluation Index (MCEDEI) based on machine learning technique cluster analysis using groundwater data of the KB region of Türkiye to assess the groundwater drought. For the development of MCEDEI, this study used 540-time series observations (range: 1978–2022) of groundwater data from five stations to evaluate drought characteristics. Furthermore, this study used steady-state probability to determine the trend and long-term probabilities of the drought index in the KB region of Türkiye. The results show that the NN (near normal) class was found to be dominant with a probability of 70.41% on a 1-month time scale, while NN was found to be dominant with a high probability of 65.94% on a 3-month time scale. The probability of the NN class was found to be equally high when the time scale was extended to 6, 9 and even 48 months. MD (moderate drought) remains important, and SD (severe drought) increases compared to SW (severe wet) classes. Findings shpw that there are significant changes in groundwater behaviour at different time scales. Short-term stability is characterized by the dominance of the NN class, while long-term scales show a trend towards extreme dry and wet conditions with a decrease in neutrality. As a result, Türkiye may face drought challenges in the future based on the findings.</div></div>","PeriodicalId":54616,"journal":{"name":"Physics and Chemistry of the Earth","volume":"139 ","pages":"Article 103901"},"PeriodicalIF":3.0,"publicationDate":"2025-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143592408","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Determination of hydroelectric capacity for ungauged catchments: A case study in Turkey
IF 3 3区 地球科学
Physics and Chemistry of the Earth Pub Date : 2025-03-05 DOI: 10.1016/j.pce.2025.103897
Ayca Aytac
{"title":"Determination of hydroelectric capacity for ungauged catchments: A case study in Turkey","authors":"Ayca Aytac","doi":"10.1016/j.pce.2025.103897","DOIUrl":"10.1016/j.pce.2025.103897","url":null,"abstract":"<div><div>One major obstacle to using flow duration and mass flow curves in the design of hydropower capacity, water allocation, energy output, etc. is the absence of data and information, especially at the tributary reaches. For hydropower design to accurately estimate generation capacity and protect the environment, long-term resource availability—represented by the discharge—must be precisely calculated. The gauged flow record will be used to predict discharges as soon as long-term gauged flows for the site catchments are available. Methods for estimating resource availability at the ungauged location are necessary, though, because the majority of river reaches are ungauged. A single or more long-term gauged catchments that are assumed to have similar hydrological characteristics to the ungauged location are often the source of local hydrometric data. The use of resource availability estimation techniques for hydropower design will be covered in this study, along with the potential use of local hydrometric data to support these estimations. We'll use a case study catchment in Turkey to talk about the uncertainties surrounding these methods.</div></div>","PeriodicalId":54616,"journal":{"name":"Physics and Chemistry of the Earth","volume":"139 ","pages":"Article 103897"},"PeriodicalIF":3.0,"publicationDate":"2025-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143580278","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Mechanical properties and stress-strain relationship of early strength polymer-modified concrete at different ages
IF 3 3区 地球科学
Physics and Chemistry of the Earth Pub Date : 2025-02-28 DOI: 10.1016/j.pce.2025.103895
Jiawei Gu , Jia Xing , Jialing Che , Siew Choo Chin
{"title":"Mechanical properties and stress-strain relationship of early strength polymer-modified concrete at different ages","authors":"Jiawei Gu ,&nbsp;Jia Xing ,&nbsp;Jialing Che ,&nbsp;Siew Choo Chin","doi":"10.1016/j.pce.2025.103895","DOIUrl":"10.1016/j.pce.2025.103895","url":null,"abstract":"<div><div>Early-strength polymer-modified concrete (ES-PMC) has demonstrated considerable promise for rapid repair applications, where its performance is critical to ensuring the safety and quality of concrete structure construction. This study examines the mechanical properties and stress-strain behavior of ES-PMC at various curing ages (1.5 h, 2 h, 3 h, 1 day, 3 days, 7 days, and 28 days), with early-strength concrete (ESC) serving as the control group. The results indicate that ES-PMC generally surpasses ESC in terms of cube compressive strength, uniaxial compressive strength, and flexural strength, achieving values of 35.8 MPa, 25.4 MPa, and 4.4 MPa, respectively, at 2 h. Furthermore, a strong linear correlation is observed between the cube compressive and uniaxial compressive strengths of both ESC and ES-PMC. Under uniaxial loading, as the curing age increases, both materials undergo greater damage, with peak stress, elastic modulus, and toughness increasing over time, while peak strain, ultimate strain, and relative energy absorption capacity decrease. Additionally, a modified stress-strain model for ES-PMC was developed, incorporating age-related factors to accurately depict its stress-strain behavior across different ages. This model provides a theoretical basis for promoting its application in practical engineering and predicting its performance at various stages.</div></div>","PeriodicalId":54616,"journal":{"name":"Physics and Chemistry of the Earth","volume":"139 ","pages":"Article 103895"},"PeriodicalIF":3.0,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143552639","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Refining historical forest cover mapping and change analysis with time series algorithm-based samples transfer
IF 3 3区 地球科学
Physics and Chemistry of the Earth Pub Date : 2025-02-23 DOI: 10.1016/j.pce.2025.103893
Qianhuizi Guo , Ling Han , Liangzhi Li , Songjie Qu
{"title":"Refining historical forest cover mapping and change analysis with time series algorithm-based samples transfer","authors":"Qianhuizi Guo ,&nbsp;Ling Han ,&nbsp;Liangzhi Li ,&nbsp;Songjie Qu","doi":"10.1016/j.pce.2025.103893","DOIUrl":"10.1016/j.pce.2025.103893","url":null,"abstract":"<div><div>Accurate forest cover maps are crucial for ecosystem monitoring and sustainable land use planning. Traditionally, supervised learning methods usually rely on high-quality ground-truth data, which makes it difficult to apply when historical data collection is costly. This study investigates the effectiveness of the LandTrendr algorithm in long-term sample transfer management. First, we assessed the performance of four commonly used machine learning models (random forest, artificial neural network, support vector machine, and XGBoost) in classifying land cover in the reference year. Then, by integrating the best model's classification results with the LandTrendr algorithm, we simplified the process of manually selecting sample points by identifying stable pixel samples, and generated a long-term dataset consistent across time scales, facilitating land cover mapping for historical periods and providing benchmark data for forest cover change analysis. The results show that, among the four models, XGBoost achieved the highest classification accuracy (overall accuracy OA = 0.87, Kappa coefficient = 0.85). By comparing the sample transfer strategy to the traditional model transfer method, we found that the LandTrendr based sample transfer method consistently achieved over 85% accuracy in forest classification throughout the study period, outperforming the direct model transfer approach. Although accuracy decreased over time, the sample transfer method demonstrated stronger consistency. Overall, this study simplifies the process of continuous field data collection by utilizing LandTrendr to transfer stable pixel samples across multiple years, providing methodological support for the dynamic analysis of forest cover changes in Shaanxi Province over time.</div></div>","PeriodicalId":54616,"journal":{"name":"Physics and Chemistry of the Earth","volume":"139 ","pages":"Article 103893"},"PeriodicalIF":3.0,"publicationDate":"2025-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143552638","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
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