Pub Date : 2025-07-03DOI: 10.1016/j.ijsrc.2025.06.011
Wenguang Luo , Yan Pan , Jing Lu , Jinxiao Zhao
Understanding wind-induced sediment resuspension is essential for predicting turbidity dynamics and nutrient cycling in shallow lakes. This study investigates the spatial variability of sediment resuspension under different hydrodynamic conditions and quantifies the influence of wind-driven forces on sediment stability. A controlled laboratory experiment was conducted using a wind-generation system comprising 13 rows of fans positioned at varying distances and angles with respect to three distinct regions (A, B, and C). Turbidity variations exhibited a strong linear correlation with the dimensionless parameter (W2/H) (R2 = 0.85–0.92), where W represents wind frequency (Hz) and H denotes water depth (m). This parameter effectively captures resuspension sensitivity. Further analysis showed that W, which reflects the proximity to the wind source, integrates the effects of both wind angle and position. Using the 50 NTU water quality threshold, critical (W2/H) values were determined as 2787, 7176, and 16,771 for regions A, B, and C, respectively—corresponding to wind frequencies of 17 Hz, 27 Hz, and 41 Hz at a depth of 0.1 m. Accordingly, regions B and C require approximately 1.6 and 2.5 times more wind energy than region A to reach the same turbidity level. These findings establish a quantitative relationship between wind-driven turbulence and sediment transport, providing insight into the spatial heterogeneity of sediment stability. This research offers both theoretical and practical implications for water quality management, including optimizing artificial aeration, mitigating eutrophication, and improving sediment regulation strategies in shallow lake ecosystems.
{"title":"Analysis of sediment resuspension in shallow lake under variable wind speed and water depth","authors":"Wenguang Luo , Yan Pan , Jing Lu , Jinxiao Zhao","doi":"10.1016/j.ijsrc.2025.06.011","DOIUrl":"10.1016/j.ijsrc.2025.06.011","url":null,"abstract":"<div><div>Understanding wind-induced sediment resuspension is essential for predicting turbidity dynamics and nutrient cycling in shallow lakes. This study investigates the spatial variability of sediment resuspension under different hydrodynamic conditions and quantifies the influence of wind-driven forces on sediment stability. A controlled laboratory experiment was conducted using a wind-generation system comprising 13 rows of fans positioned at varying distances and angles with respect to three distinct regions (A, B, and C). Turbidity variations exhibited a strong linear correlation with the dimensionless parameter (<em>W</em><sup>2</sup>/<em>H</em>) (<em>R</em><sup>2</sup> = 0.85–0.92), where <em>W</em> represents wind frequency (Hz) and <em>H</em> denotes water depth (m). This parameter effectively captures resuspension sensitivity. Further analysis showed that W, which reflects the proximity to the wind source, integrates the effects of both wind angle and position. Using the 50 NTU water quality threshold, critical (<em>W</em><sup>2</sup>/<em>H</em>) values were determined as 2787, 7176, and 16,771 for regions A, B, and C, respectively—corresponding to wind frequencies of 17 Hz, 27 Hz, and 41 Hz at a depth of 0.1 m. Accordingly, regions B and C require approximately 1.6 and 2.5 times more wind energy than region A to reach the same turbidity level. These findings establish a quantitative relationship between wind-driven turbulence and sediment transport, providing insight into the spatial heterogeneity of sediment stability. This research offers both theoretical and practical implications for water quality management, including optimizing artificial aeration, mitigating eutrophication, and improving sediment regulation strategies in shallow lake ecosystems.</div></div>","PeriodicalId":50290,"journal":{"name":"International Journal of Sediment Research","volume":"41 1","pages":"Pages 36-44"},"PeriodicalIF":3.7,"publicationDate":"2025-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145929124","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Continuous water and sediment flow monitoring across river cross sections is essential for the management of flood- and sediment-related problems in watersheds. The sediment rating curve (SRC) estimates missing or uncertain sediment flow via its corresponding water discharge. Generally, a power form of relationship correlates the two quantities. The log-transformed water discharge and sediment discharge data were used to depict the SRCs developed in the present study. SRC parameter estimation via least squares regression using at-site dataset pairs can be found in the literature. However, the availability of reliable datasets at the site limits model applicability. This method does not describe the SRC on the basis of the continuity aspects of river system flow characteristics. Therefore, the current study proposes integrated SRC estimation models (Model 2 and Model 3) using modified Muskingum equations abiding by the spatial and temporal continuity of the entire river system state. These models are derived from streamflow storage balance criteria and ensure flow continuity norms. Moreover, Model 3 considers an inverse power form of the relationship depicting the water flow characteristics that govern the sediment transport phenomena through the river system. Standalone models for SRC parameter estimation (Model 1) were also developed for comparison among all three models via the root mean square error (RMSE), NRMSE (normalized root mean square error) and coefficient of determination (R2). The Mahanadi River system within Chhattisgarh state, India comprises five sections at tributaries, and the main channel was considered for the study. The improved NRMSE by Model 2 (7.53%) and Model 3 (7.14%) at Rajim and Model 3 (3.44%) at Bamnidhi in comparison to Model 1 at Rajim (9.19%) and Bamnidhi (4.80%) encouraged the application of integrated models for SRC estimation in river systems. Moreover, Model 3 outperformed Model 2 in some cases where the sediment transport process may be governed by water flow characteristics.
{"title":"River system sediment rating curve parameter estimation via integrated models","authors":"Tushar Khankhoje, Samrat Boro, Parthasarathi Choudhury","doi":"10.1016/j.ijsrc.2025.06.010","DOIUrl":"10.1016/j.ijsrc.2025.06.010","url":null,"abstract":"<div><div>Continuous water and sediment flow monitoring across river cross sections is essential for the management of flood- and sediment-related problems in watersheds. The sediment rating curve (SRC) estimates missing or uncertain sediment flow via its corresponding water discharge. Generally, a power form of relationship correlates the two quantities. The log-transformed water discharge and sediment discharge data were used to depict the SRCs developed in the present study. SRC parameter estimation via least squares regression using at-site dataset pairs can be found in the literature. However, the availability of reliable datasets at the site limits model applicability. This method does not describe the SRC on the basis of the continuity aspects of river system flow characteristics. Therefore, the current study proposes integrated SRC estimation models (Model 2 and Model 3) using modified Muskingum equations abiding by the spatial and temporal continuity of the entire river system state. These models are derived from streamflow storage balance criteria and ensure flow continuity norms. Moreover, Model 3 considers an inverse power form of the relationship depicting the water flow characteristics that govern the sediment transport phenomena through the river system. Standalone models for SRC parameter estimation (Model 1) were also developed for comparison among all three models via the root mean square error (RMSE), NRMSE (normalized root mean square error) and coefficient of determination (<em>R</em><sup>2</sup>). The Mahanadi River system within Chhattisgarh state, India comprises five sections at tributaries, and the main channel was considered for the study. The improved NRMSE by Model 2 (7.53%) and Model 3 (7.14%) at Rajim and Model 3 (3.44%) at Bamnidhi in comparison to Model 1 at Rajim (9.19%) and Bamnidhi (4.80%) encouraged the application of integrated models for SRC estimation in river systems. Moreover, Model 3 outperformed Model 2 in some cases where the sediment transport process may be governed by water flow characteristics.</div></div>","PeriodicalId":50290,"journal":{"name":"International Journal of Sediment Research","volume":"41 1","pages":"Pages 45-59"},"PeriodicalIF":3.7,"publicationDate":"2025-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145929125","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-06-13DOI: 10.1016/j.ijsrc.2025.06.006
Jun Zhang , Yingbiao Shi , Guojian He
The critical condition of sediment incipient motion (SIM) is one of the most pivotal and fundamental topics for the mechanics of sediment transport in offshore areas. The flocculation of fine sediment exerts a complex influence on SIM, particularly in bay areas where the water salinity varies. This paper analyzes data measured in Hangzhou Bay with 50 observation points from 2005 to 2019. The objective is to ascertain the effect of salinity on the critical velocity of SIM (uc), figure out the calculation error of traditional equations for uc in saline water and improve the calculation accuracy of uc. Results indicate that the calculation error rate of traditional uc equations escalates with the increased clay content of bottom sediment and water salinity. An improved uc equation in saline water environment is constructed with the consideration of clay content and salinity based on a traditional equation. The improved equation is fitted through measured data and validated with the experimental data. The accuracy of the improved equation significantly increases compared to traditional equations in the area with clay content over 15% and salinity over 12‰.
{"title":"Study on the critical velocity of sediment incipient motion in saline water based on Hangzhou Bay field investigation","authors":"Jun Zhang , Yingbiao Shi , Guojian He","doi":"10.1016/j.ijsrc.2025.06.006","DOIUrl":"10.1016/j.ijsrc.2025.06.006","url":null,"abstract":"<div><div>The critical condition of sediment incipient motion (SIM) is one of the most pivotal and fundamental topics for the mechanics of sediment transport in offshore areas. The flocculation of fine sediment exerts a complex influence on SIM, particularly in bay areas where the water salinity varies. This paper analyzes data measured in Hangzhou Bay with 50 observation points from 2005 to 2019. The objective is to ascertain the effect of salinity on the critical velocity of SIM (<em>u</em><sub><em>c</em></sub>), figure out the calculation error of traditional equations for <em>u</em><sub><em>c</em></sub> in saline water and improve the calculation accuracy of <em>u</em><sub><em>c</em></sub>. Results indicate that the calculation error rate of traditional <em>u</em><sub><em>c</em></sub> equations escalates with the increased clay content of bottom sediment and water salinity. An improved <em>u</em><sub><em>c</em></sub> equation in saline water environment is constructed with the consideration of clay content and salinity based on a traditional equation. The improved equation is fitted through measured data and validated with the experimental data. The accuracy of the improved equation significantly increases compared to traditional equations in the area with clay content over 15% and salinity over 12‰.</div></div>","PeriodicalId":50290,"journal":{"name":"International Journal of Sediment Research","volume":"40 6","pages":"Pages 878-889"},"PeriodicalIF":3.7,"publicationDate":"2025-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145486281","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-05-29DOI: 10.1016/j.ijsrc.2025.05.006
Dandan Li , Xiaoyan Chen , Pingzong Zhu , Wenhao Tan , Tingting Tao , Liwen Ma , Lingyong Kong
As a specific near surface hydrological condition, soil saturation can significantly affect the critical hydrodynamic characteristic and soil erosion rate of rill formation, leading to severe rill erosion. Nevertheless, few studies have investigated the characteristics of critical hydrodynamic parameters and their relationships with rill erosion rate under critical hydrodynamic conditions of rill formation on saturated soil slopes. Consequently, the quantification of critical hydrodynamic parameters and their effects on rill erosion rate under critical hydrodynamic conditions of rill formation on saturated soil slopes is of great significance for understanding the dynamic mechanism of rill formation and evolution and for predicting and controlling soil loss. In this study, indoor simulated rainfall experiments were performed and a new analytical model (Vc(NAM)) was applied to calculate the aforementioned critical parameters under a wide range of hydraulic conditions comprising five slope gradients (SG) (2°, 5°, 10°, 15°, and 20°) and three rainfall intensities (RI) (30, 60, and 90 mm/h). The results indicated that the new analytical model (Vc(NAM)) was suitable for estimating critical hydrodynamic parameters on saturated soil slopes. The critical flow velocity (Vc), the critical shear stress (τc), and the critical stream power (ωc) apparently increased, whereas the critical rill length (Lc) decreased with the increase of slope gradients and rainfall intensities. Moreover, the erosion rate at the critical condition increased with decreasing Lc and increasing Vc, τc, and ωc. Pearson correlation analysis indicated that τc and ωc were significantly positively correlated, whereas Lc was negatively correlated with erosion rate under the critical conditions. Stepwise regression analysis revealed that the erosion rate under critical hydrodynamic conditions of rill formation could be well predicted by τc (R2 = 0.83) with the linear model. The results provide an accurate model for evaluating critical conditions of rill formation and a basis for further understanding the intrinsic dynamic mechanism of rill formation on saturated soil slopes.
{"title":"Evaluating critical hydrodynamic characteristics of rill formation on saturated soil slopes","authors":"Dandan Li , Xiaoyan Chen , Pingzong Zhu , Wenhao Tan , Tingting Tao , Liwen Ma , Lingyong Kong","doi":"10.1016/j.ijsrc.2025.05.006","DOIUrl":"10.1016/j.ijsrc.2025.05.006","url":null,"abstract":"<div><div>As a specific near surface hydrological condition, soil saturation can significantly affect the critical hydrodynamic characteristic and soil erosion rate of rill formation, leading to severe rill erosion. Nevertheless, few studies have investigated the characteristics of critical hydrodynamic parameters and their relationships with rill erosion rate under critical hydrodynamic conditions of rill formation on saturated soil slopes. Consequently, the quantification of critical hydrodynamic parameters and their effects on rill erosion rate under critical hydrodynamic conditions of rill formation on saturated soil slopes is of great significance for understanding the dynamic mechanism of rill formation and evolution and for predicting and controlling soil loss. In this study, indoor simulated rainfall experiments were performed and a new analytical model (<em>V</em><sub>c(NAM)</sub>) was applied to calculate the aforementioned critical parameters under a wide range of hydraulic conditions comprising five slope gradients (<em>S</em><sub>G</sub>) (2°, 5°, 10°, 15°, and 20°) and three rainfall intensities (<em>R</em><sub>I</sub>) (30, 60, and 90 mm/h). The results indicated that the new analytical model (<em>V</em><sub>c(NAM)</sub>) was suitable for estimating critical hydrodynamic parameters on saturated soil slopes. The critical flow velocity (<em>V</em><sub>c</sub>), the critical shear stress (<em>τ</em><sub>c</sub>), and the critical stream power (<em>ω</em><sub>c</sub>) apparently increased, whereas the critical rill length (<em>L</em><sub>c</sub>) decreased with the increase of slope gradients and rainfall intensities. Moreover, the erosion rate at the critical condition increased with decreasing <em>L</em><sub>c</sub> and increasing <em>V</em><sub>c</sub>, <em>τ</em><sub>c</sub>, and <em>ω</em><sub>c</sub>. Pearson correlation analysis indicated that <em>τ</em><sub>c</sub> and <em>ω</em><sub>c</sub> were significantly positively correlated, whereas <em>L</em><sub>c</sub> was negatively correlated with erosion rate under the critical conditions. Stepwise regression analysis revealed that the erosion rate under critical hydrodynamic conditions of rill formation could be well predicted by <em>τ</em><sub>c</sub> (<em>R</em><sup>2</sup> = 0.83) with the linear model. The results provide an accurate model for evaluating critical conditions of rill formation and a basis for further understanding the intrinsic dynamic mechanism of rill formation on saturated soil slopes.</div></div>","PeriodicalId":50290,"journal":{"name":"International Journal of Sediment Research","volume":"40 4","pages":"Pages 666-674"},"PeriodicalIF":3.5,"publicationDate":"2025-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144549626","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-05-26DOI: 10.1016/j.ijsrc.2025.05.003
Zihao Tang , Bruce W. Melville , Naresh Singhal , Asaad Y. Shamseldin , Liang Cheng , Dawei Guan
Microbially induced calcite precipitation (MICP) is an emerging method for mitigating scour and erosion. The present study experimentally investigates the efficacy of MICP as a local scour countermeasure for offshore wind turbine monopile foundations under both clear water and live-bed conditions. Bacteria were enriched using activated sludge. Analyses conducted included urease activity monitoring, unconfined compression testing, and examination using scanning electron microscopy. Various depths for the MICP protection elevation were tested in clear water conditions, and the resulting scour topography was mapped using photogrammetry techniques. Investigations were conducted on bedform migration and leading-edge scour upstream of the MICP protection, considering various protection elevations. The results indicated that MICP protection can provide effective scour protection under both clear water and live-bed conditions. Discussions in this study also extend to the erosion and potential collapse of the MICP protection structure. Flow undercut rate were also examined for evaluating potential failure of MICP protection structures, and the elevation of MICP protection has a significant influence on mitigating flow undercutting. Full protection efficiency was observed under clear water conditions when the MICP protection elevation was at the bed level and the flow intensity was relatively low (V/Vc = 0.65), while the highest average protection efficiency (47.73%) among all flow intensities was recorded when the MICP protection elevation was at 0.6D below the bed.
{"title":"Performance of microbially induced calcite precipitation (MICP) as a local scour countermeasure for offshore wind turbine monopile foundation","authors":"Zihao Tang , Bruce W. Melville , Naresh Singhal , Asaad Y. Shamseldin , Liang Cheng , Dawei Guan","doi":"10.1016/j.ijsrc.2025.05.003","DOIUrl":"10.1016/j.ijsrc.2025.05.003","url":null,"abstract":"<div><div>Microbially induced calcite precipitation (MICP) is an emerging method for mitigating scour and erosion. The present study experimentally investigates the efficacy of MICP as a local scour countermeasure for offshore wind turbine monopile foundations under both clear water and live-bed conditions. Bacteria were enriched using activated sludge. Analyses conducted included urease activity monitoring, unconfined compression testing, and examination using scanning electron microscopy. Various depths for the MICP protection elevation were tested in clear water conditions, and the resulting scour topography was mapped using photogrammetry techniques. Investigations were conducted on bedform migration and leading-edge scour upstream of the MICP protection, considering various protection elevations. The results indicated that MICP protection can provide effective scour protection under both clear water and live-bed conditions. Discussions in this study also extend to the erosion and potential collapse of the MICP protection structure. Flow undercut rate were also examined for evaluating potential failure of MICP protection structures, and the elevation of MICP protection has a significant influence on mitigating flow undercutting. Full protection efficiency was observed under clear water conditions when the MICP protection elevation was at the bed level and the flow intensity was relatively low (<em>V/V</em><sub>c</sub> = 0.65), while the highest average protection efficiency (47.73%) among all flow intensities was recorded when the MICP protection elevation was at 0.6<em>D</em> below the bed.</div></div>","PeriodicalId":50290,"journal":{"name":"International Journal of Sediment Research","volume":"40 4","pages":"Pages 627-650"},"PeriodicalIF":3.5,"publicationDate":"2025-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144549624","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-05-16DOI: 10.1016/j.ijsrc.2025.05.002
Ya Zhou , Lei Huang , Liangwen Huang , Jiafu Liu
Global-scale changes in precipitation and temperature lead to regional variations in the hydrologic cycle. Understanding the impacts of climate change on discharge and sediment processes is crucial for effective watershed management, especially in alpine regions. A hydrologic modeling framework was established for the Yarlung Tsangpo River (YTR) watershed, the largest and longest river system on the Tibetan Plateau, which integrates the Soil and Water Assessment Tool (SWAT) with global climate models (GCMs) from the Coupled Model Intercomparison Project Phase 6 (CMIP6). The results highlight the importance of temperature in influencing hydrological elements during snowmelt periods in the northeastern and western parts of the YTR basin and precipitation across the entire basin during rainy periods. Compared with discharge, sediment flux has been more sensitive to climate change over the past four decades. The annual mean discharge at the downstream station is projected to decrease by −3.60% ± 2.68% in the near-term period (2025–2035) but increases by 4.18% ± 3.30% in the mid-term period (2040–2050) relative to the baseline value of 2000–2014. Moreover, the annual mean sediment flux is expected to change by −1.06% ± 2.98% in the near-term period and by 8.30% ± 3.65% in the mid-term period. These results will enhance adaptive management and policy-making for alpine regions.
{"title":"Identifying the effects of climate change on discharge and sediment transport in a typical alpine basin","authors":"Ya Zhou , Lei Huang , Liangwen Huang , Jiafu Liu","doi":"10.1016/j.ijsrc.2025.05.002","DOIUrl":"10.1016/j.ijsrc.2025.05.002","url":null,"abstract":"<div><div>Global-scale changes in precipitation and temperature lead to regional variations in the hydrologic cycle. Understanding the impacts of climate change on discharge and sediment processes is crucial for effective watershed management, especially in alpine regions. A hydrologic modeling framework was established for the Yarlung Tsangpo River (YTR) watershed, the largest and longest river system on the Tibetan Plateau, which integrates the Soil and Water Assessment Tool (SWAT) with global climate models (GCMs) from the Coupled Model Intercomparison Project Phase 6 (CMIP6). The results highlight the importance of temperature in influencing hydrological elements during snowmelt periods in the northeastern and western parts of the YTR basin and precipitation across the entire basin during rainy periods. Compared with discharge, sediment flux has been more sensitive to climate change over the past four decades. The annual mean discharge at the downstream station is projected to decrease by −3.60% ± 2.68% in the near-term period (2025–2035) but increases by 4.18% ± 3.30% in the mid-term period (2040–2050) relative to the baseline value of 2000–2014. Moreover, the annual mean sediment flux is expected to change by −1.06% ± 2.98% in the near-term period and by 8.30% ± 3.65% in the mid-term period. These results will enhance adaptive management and policy-making for alpine regions.</div></div>","PeriodicalId":50290,"journal":{"name":"International Journal of Sediment Research","volume":"40 4","pages":"Pages 551-560"},"PeriodicalIF":3.5,"publicationDate":"2025-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144549465","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-04-25DOI: 10.1016/j.ijsrc.2025.04.005
Jing Guo , Zihan Pan , Xiaomin Yan , Man Wu , Hengtong Qiu , Wanyi Li , Wenlong Huang , Di Wu , Baoming Xue , Zhiming Mo , Guilin Xu
Elucidating the historical variation of biogenic elements and source provenance in coastal areas is crucial to better understand environmental evolution and organize ecological management. In this study, the spatiotemporal distribution of biogenic elements (carbon (C), nitrogen (N), phosphorus (P), and silicon (Si)), and carbon and nitrogen isotopes (δ13C and δ15N), respectively in sediment were explored to illustrate elemental changes and determine sources of sedimentary organic matter (SOM) in the coastal regions of northern Beibu Gulf (CNBG). C, N, and P contents exhibited a general decreasing pattern from estuaries to offshore areas, probably due to terrigenous inputs and sediment textures. Since Si was mainly associated with diatoms, lower Si was attributed to the depression of phytoplankton growth by oyster beds in estuaries of Fangcheng Bay and the Maowei Sea. Based on a δ13C and δ15N three-end-member mixing model, it revealed that the average contribution of terrigenous plants and shellfish biodeposition for SOM were 56.00% and 22.39% in the intensive mariculture region (IMR), indicating that terrestrial sources and mariculture biodeposits played a prominent role as SOM sources. Additionally, according to three lead 210 (210Pb) dated sediment cores, it was found that elemental contents and elemental burial rates increased along with the coastal development after 1980s, particularly since 2006 when the Beibu Gulf Economic Zone was established. Multiple Linear Regression results showed that C and N contents and sedimentation rates were responsible for the variation of carbon burial rates during the past decades. More importantly, the significant positive relation between elemental contents and population, and gross domestic product (GDP) growth further proved a close relation between environmental evolution in the CNBG and the socioeconomic development of Guangxi Province. Moreover, the different trends of SOM source contribution for three sediment cores demonstrated the evolution characteristics among different coastal environments. The elevated δ13C and δ15N manifested the increasing contribution of marine phytoplankton (46.83%–69.33%) to SOM in Sanniang Bay recently, where frequent occurrence and decomposition of algal blooms resulted in more SOM. The dominant fraction of terrestrial sources (76.50% ± 13.27%, where ± indicates a standard deviation bound) to SOM in Lianzhou Bay implied the significant impacts of riverine inputs and fishing activities during the last century. This study indicates human activities have led to the continuous increase in nutrients, which has caused ecological risks such as algal blooms in the CNBG, thus, the mitigation of coastal eutrophication needs close attention.
{"title":"Environmental evolution of coastal regions in northern Beibu Gulf, South China, based on sedimentary elemental records and carbon-nitrogen isotope composition","authors":"Jing Guo , Zihan Pan , Xiaomin Yan , Man Wu , Hengtong Qiu , Wanyi Li , Wenlong Huang , Di Wu , Baoming Xue , Zhiming Mo , Guilin Xu","doi":"10.1016/j.ijsrc.2025.04.005","DOIUrl":"10.1016/j.ijsrc.2025.04.005","url":null,"abstract":"<div><div>Elucidating the historical variation of biogenic elements and source provenance in coastal areas is crucial to better understand environmental evolution and organize ecological management. In this study, the spatiotemporal distribution of biogenic elements (carbon (C), nitrogen (N), phosphorus (P), and silicon (Si)), and carbon and nitrogen isotopes (δ<sup>13</sup>C and δ<sup>15</sup>N), respectively in sediment were explored to illustrate elemental changes and determine sources of sedimentary organic matter (SOM) in the coastal regions of northern Beibu Gulf (CNBG). C, N, and P contents exhibited a general decreasing pattern from estuaries to offshore areas, probably due to terrigenous inputs and sediment textures. Since Si was mainly associated with diatoms, lower Si was attributed to the depression of phytoplankton growth by oyster beds in estuaries of Fangcheng Bay and the Maowei Sea. Based on a δ<sup>13</sup>C and δ<sup>15</sup>N three-end-member mixing model, it revealed that the average contribution of terrigenous plants and shellfish biodeposition for SOM were 56.00% and 22.39% in the intensive mariculture region (IMR), indicating that terrestrial sources and mariculture biodeposits played a prominent role as SOM sources. Additionally, according to three lead 210 (<sup>210</sup>Pb) dated sediment cores, it was found that elemental contents and elemental burial rates increased along with the coastal development after 1980s, particularly since 2006 when the Beibu Gulf Economic Zone was established. Multiple Linear Regression results showed that C and N contents and sedimentation rates were responsible for the variation of carbon burial rates during the past decades. More importantly, the significant positive relation between elemental contents and population, and gross domestic product (GDP) growth further proved a close relation between environmental evolution in the CNBG and the socioeconomic development of Guangxi Province. Moreover, the different trends of SOM source contribution for three sediment cores demonstrated the evolution characteristics among different coastal environments. The elevated δ<sup>13</sup>C and δ<sup>15</sup>N manifested the increasing contribution of marine phytoplankton (46.83%–69.33%) to SOM in Sanniang Bay recently, where frequent occurrence and decomposition of algal blooms resulted in more SOM. The dominant fraction of terrestrial sources (76.50% ± 13.27%, where ± indicates a standard deviation bound) to SOM in Lianzhou Bay implied the significant impacts of riverine inputs and fishing activities during the last century. This study indicates human activities have led to the continuous increase in nutrients, which has caused ecological risks such as algal blooms in the CNBG, thus, the mitigation of coastal eutrophication needs close attention.</div></div>","PeriodicalId":50290,"journal":{"name":"International Journal of Sediment Research","volume":"40 4","pages":"Pages 600-615"},"PeriodicalIF":3.5,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144549462","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-04-24DOI: 10.1016/j.ijsrc.2025.04.004
Yuan He , Zihao Fan , Wei Zhao , Zhihao Tian , Dingmeng Hu , Zixu Zhang , Yucun Lu , Peng Gao
Vegetation litter is effective in mitigating surface soil erosion caused by rainfall and runoff. Studying the runoff, sediment yield, and hydrodynamic characteristics of the soil covered by vegetation litter cover is crucial to understanding how vegetation litter cover affects soil erosion. To assess the impacts of different types of vegetation litter on soil erosion in the Taiyi Mountain area of northern China, Quercus acutissima Carruth. (QAC), Pinus densiflora Siebold & Zucc. (PDS), Vitex negundo var. heterophylla Rehd. (VNH), and Themeda japonica Willd. (TJW) litter covered soil were the research subjects, and no-litter covered soil was used as a control check (CK). The process of erosion of soil covered by different vegetation litter under different rainfall intensities (50, 75, and 100 mm/h) with 60 min of rainfall was studied. It was found that compared with CK, the runoff and sediment yield rates of litter-covered soil decreased by 18.95%–44.15% and 21.42%–60.16%, respectively. In terms of the effect on reducing the runoff and sediment yield rate, the performance is QAC > PDS > VNH > TJW. Under varying rainfall intensities, the patterns of runoff and sediment yield fluctuate as rainfall duration increases. Likewise, with the increase in rainfall intensity, the runoff yield rate and sediment yield rate also show an increasing trend. The runoff yield rate was increased by 3.21 and 1.49 times under 100 mm/h compared with 50 and 75 mm/h, respectively. Additionally, there were 16.56 and 1.44 times, respectively, and increases in the sediment yield rate. Hydrodynamically, litter cover increases the Darcy-Weisbach friction coefficient by 1.49–11.15 times, increases the shear stress threshold for initiating soil erosion by about 6.67%–38.01%. This further led to a reduction in the runoff flow velocity and stream power, by approximately 14.87%–67.26% and 7.38%–61.54%, respectively, thereby reducing the degree of soil erosion. The current research demonstrates that the characteristics of soil erosion and sediment yield under vegetation litter cover can be more accurately described by the stream power among the hydrodynamic parameters.
{"title":"Effects of different vegetation litter cover on hydrodynamic characteristics of soil runoff-sediment yield in Taiyi Mountain area of northern China","authors":"Yuan He , Zihao Fan , Wei Zhao , Zhihao Tian , Dingmeng Hu , Zixu Zhang , Yucun Lu , Peng Gao","doi":"10.1016/j.ijsrc.2025.04.004","DOIUrl":"10.1016/j.ijsrc.2025.04.004","url":null,"abstract":"<div><div>Vegetation litter is effective in mitigating surface soil erosion caused by rainfall and runoff. Studying the runoff, sediment yield, and hydrodynamic characteristics of the soil covered by vegetation litter cover is crucial to understanding how vegetation litter cover affects soil erosion. To assess the impacts of different types of vegetation litter on soil erosion in the Taiyi Mountain area of northern China, <em>Quercus acutissima</em> Carruth. (QAC), <em>Pinus densiflora</em> Siebold & Zucc. (PDS), <em>Vitex negundo</em> var. <em>heterophylla</em> Rehd. (VNH), and <em>Themeda japonica</em> Willd. (TJW) litter covered soil were the research subjects, and no-litter covered soil was used as a control check (CK). The process of erosion of soil covered by different vegetation litter under different rainfall intensities (50, 75, and 100 mm/h) with 60 min of rainfall was studied. It was found that compared with CK, the runoff and sediment yield rates of litter-covered soil decreased by 18.95%–44.15% and 21.42%–60.16%, respectively. In terms of the effect on reducing the runoff and sediment yield rate, the performance is QAC > PDS > VNH > TJW. Under varying rainfall intensities, the patterns of runoff and sediment yield fluctuate as rainfall duration increases. Likewise, with the increase in rainfall intensity, the runoff yield rate and sediment yield rate also show an increasing trend. The runoff yield rate was increased by 3.21 and 1.49 times under 100 mm/h compared with 50 and 75 mm/h, respectively. Additionally, there were 16.56 and 1.44 times, respectively, and increases in the sediment yield rate. Hydrodynamically, litter cover increases the Darcy-Weisbach friction coefficient by 1.49–11.15 times, increases the shear stress threshold for initiating soil erosion by about 6.67%–38.01%. This further led to a reduction in the runoff flow velocity and stream power, by approximately 14.87%–67.26% and 7.38%–61.54%, respectively, thereby reducing the degree of soil erosion. The current research demonstrates that the characteristics of soil erosion and sediment yield under vegetation litter cover can be more accurately described by the stream power among the hydrodynamic parameters.</div></div>","PeriodicalId":50290,"journal":{"name":"International Journal of Sediment Research","volume":"40 4","pages":"Pages 588-599"},"PeriodicalIF":3.5,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144549461","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-04-23DOI: 10.1016/j.ijsrc.2025.04.001
N. Al-Kharousi, A.R. Kacimov, A. Al-Maktoumi, S.S. Al-Ismaily
Sidr (Christ-thorn) phreatopytic-xerophitic wild trees growing in the reservoir area of the Al-Khoud groundwater recharge/flood protection dam in Muscat (Oman) were surveyed. Trees’ loci, heights and stem diameters were measured. Soil profiles were described in two pedons (trenches) excavated near two pilot trees. A remarkable increase in infiltration rate was observed when double-ring infiltrometers were placed near the tree stems and at the bottom of the trenches. Sap flow metering conducted on one tree over a period of 9 months resulted an average rate of 12.5 L/d. This value was used to evaluate the reservoir water balance, considering it as the difference between infiltration of ponded post-flash-flood water and transpiration. Sidr trees are recommended as excellent eco-engineers, that can alleviate the negative impact of reservoir bed siltation by enhancing the infiltration-recharge of the underlying aquifer.
{"title":"Can desert phreatophytic trees enhance recharge through sediment-clogged reservoirs of recharge dams in Arabia?","authors":"N. Al-Kharousi, A.R. Kacimov, A. Al-Maktoumi, S.S. Al-Ismaily","doi":"10.1016/j.ijsrc.2025.04.001","DOIUrl":"10.1016/j.ijsrc.2025.04.001","url":null,"abstract":"<div><div>Sidr (Christ-thorn) phreatopytic-xerophitic wild trees growing in the reservoir area of the Al-Khoud groundwater recharge/flood protection dam in Muscat (Oman) were surveyed. Trees’ loci, heights and stem diameters were measured. Soil profiles were described in two pedons (trenches) excavated near two pilot trees. A remarkable increase in infiltration rate was observed when double-ring infiltrometers were placed near the tree stems and at the bottom of the trenches. Sap flow metering conducted on one tree over a period of 9 months resulted an average rate of 12.5 L/d. This value was used to evaluate the reservoir water balance, considering it as the difference between infiltration of ponded post-flash-flood water and transpiration. Sidr trees are recommended as excellent eco-engineers, that can alleviate the negative impact of reservoir bed siltation by enhancing the infiltration-recharge of the underlying aquifer.</div></div>","PeriodicalId":50290,"journal":{"name":"International Journal of Sediment Research","volume":"40 4","pages":"Pages 616-626"},"PeriodicalIF":3.5,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144549463","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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