River Sediments Research Articles

The response of microbial communities to environmental factors in bank soil and river sediment: A case study along the mainstream of the Yangtze River.

Microbial communities, which are crucial for ecosystem function and sustainability, are under environmental pressure. Using phospholipid fatty acids (PLFAs) as a measure of microbial biomass and community structure, the responses of microorganisms to environmental drivers were studied in bank soil and sediment alongside the Yangtze River in China. Thirty-eight sites were investigated over a length of 5500km, ranging from the plateau to the estuary. Redundancy analysis revealed that microbial community composition in the bank soil was affected by MP (7.8%), geography (19.2%), and physicochemical properties (23.1%), while in the sediment, relevant factors were MP additives (12.8%), metals (21.1%), and physicochemical properties (23.3%). Variations in climate conditions along the course of the river had no effect on the microbial communities in the two habitats. Linear discriminant analysis of the PLFAs profiles showed changes in microbial community composition due to land use (forest, grass, cropland and built land), site class (up-, mid- and downstream) and MPs pollution level in both bank soil and sediment. The increased Gram-positive to negative bacteria (g+/g-) ratio and decreased iso-to anteiso-fatty acid (i/a) ratio indicated greater stress, such as caused by MP pollution (g+/g-: 12.6 to 19.3; i/a: 1.9 to 1.6). In bank soil, total microbial biomass was influenced by urbanization rate and nutrient availability. Specifically, total carbon (TC), total phosphorus (TP), and ammonium nitrogen (NH4+-N) had a positive impact, while inorganic phosphorus (IP), total potassium (TK) and nitrate nitrogen (NO3--N) had a negative impact. In contrast, in sediment only TC had a negative effect on biomass. This study applied PLFA to explore microbial communities and structures responses to environmental drivers in riverine habitats, revealing that anthropogenic factors (e.g. MP pollution and nutrient enrichment) alter microbial communities with urbanization.

A modified QuEChERS method for quantifying pharmaceutical residues in sediments collected in West Lake, Yen So Lake and Red River (Hanoi) in North Vietnam

ABSTRACT The occurrence of pharmaceutical residues in the environment has sparked interest in developing a multi-residue method to analyse a broader range of compounds. This study focuses on the development and validation of a methodology that employs QuEChERS extractions combined with UPLC-MS/MS, enabling simultaneous detection and quantification of pharmaceutical compounds from diverse therapeutic classes (fluoroquinolones, sulphonamides, anticonvulsants, tetracyclines, macrolides, β – blocker, cephalosporins and anti-inflammatory non-steroids) in sediments. The extraction using 0.2 M Na2-EDTA solution and 0.5% acetic acid in MeOH, partitioning by MgSO4/NaOAc (4:1) and cleaning up by C18 sorbent. The analytical performance demonstrated commendable accuracy (trueness and precision), alongside favourable linearity, with MDLs approaching relevant environmental samples, allowing for trace analysis. The MDLs ranged from 0.03 to 2.2 ng/g dried weight (d.w) while slightly lower than IDLs and varied from 0.001 to 0.1 ng/mL. The recovery test yielded satisfactory results (40–120%) for 11 compounds. The optimised method has been effectively applied to quantify the concentration of pharmaceutical residues in surface sediments collected from several locations including Red River (within Hanoi), West Lake and Yen So Lake, with five samples collected at each site. The five compounds (SMZ, TMP, AZM, SOL and DIC) were quantified with the concentration ranged from 1.5 to 56.8 ng/g d.w. in lake sediments, while only CTX was detected in one-fifth river sediments at 10.2 ng/g d.w.

Chronic enrichment affects nitrogen removal in tidal freshwater river and estuarine creek sediments.

Population growth in coastal areas increases nitrogen inputs to receiving waterways and degrades water quality. Wetland habitats, including floodplain forests and marshes, can be effective nitrogen sinks; however, little is known about the effects of chronic point source nutrient enrichment on sediment nitrogen removal in tidally influenced coastal systems. This study characterizes enrichment patterns in two tidal systems affected by wastewater treatment facility (WWTF) effluent and assesses the impact on habitat nitrogen removal via denitrification. We collected intact sediment cores from prevalent habitats in a tidal freshwater river (TFZ; swamp forest) and a tidal estuarine creek system (EST; salt marsh) upstream and downstream of a WWTF outfall, and quantified dissolved gas fluxes across the sediment-water interface during wet conditions in early summer and dry conditions in late summer. Data collected during two synoptic water quality monitoring campaigns complimented laboratory experiments to provide environmental context for biogeochemical processing. The two systems exhibited different enrichment patterns such that the river-dominated TFZ system was characterized by consistently elevated nitrate + nitrite concentrations downstream of the WWTF, whereas precipitation and tidal influence affected nutrient distributions in the EST creek. Downstream sediments in TFZ exhibit an apparent saturation response, while upstream rates may be limited by other factors, such as labile organic matter availability. In contrast, downstream sediments in EST denitrify at higher rates than upstream during wet conditions that may enhance transport of effluent. This work provides information on ecosystem functioning in human-influenced environments and can be of use in developing nature-based solutions, such as water treatment wetlands, for nitrogen removal.

Monitoring deposition and resuspension of the iron ore tailings in the Doce River after the Fundão Dam rupture

The Doce River, located in Southeast Brazil, is of great importance in supplying water for urban use, agriculture, fishing and other purposes. It was affected by a disaster that occurred on November 5, 2015 due to the collapse of the Fundão ore tailing dam, in the municipality of Mariana (MG). This disaster generated socio-environmental consequences, as some regions were severely affected due to the waste released in the river, which was considered potentially toxic in the short to long term. This work presents a temporal analysis of images from the Landsat 8 satellite, associating the aspects of rainfall in dry and rainy months, in years before and after the disaster (2014, 2015, 2016, and 2020), together with the Normalized Difference Water Index (NDWI) obtained by image digital processing, to analyze the relation between dry and rainy periods and the spectral response of images. This analysis allowed the understanding of the behavior of the suspended materials, before and after the disaster, to unravel how the dispersion of tailings occurs. Part of the ore tailing that was deposited along the river went into suspension again in the rainy season one year after the disaster and, five years after, the satellite images show no difference compared to pre-disaster conditions. But, seven years after the spill, there are still iron ore tailings deposited and mixed with the river sediments. The fluvial dynamics are incorporating the tailings into the sediments, originating conducive places to provide various types of metals adhered to the particulate matter. Keywords: iron ore tailings, rainfall, remote sensing.

Treated wastewater disturb the distributions of microplastics in their receiving watersheds.

Microplastics (MPs) are ubiquitous in aquatic environments, threatening the security of aquatic organisms. Identifying the emission node and hot spot of MPs holds significant importance in the pollution control of MPs. Wastewater is widely recognized as sink and source of MPs, while the direct evidence is insufficient. To confirm the impact of the treated wastewater on the distribution of MPs in their receiving watersheds, MPs in surface river water and sediment samples collected around a typical industrial (petrochemical) and a municipal wastewater treatment plant (PWWTP and MWWTP) were identified. Results revealed that effluent from the PWWTP and water near the outfall of the MWWTP owned the most abundant MPs of 1280, and 723 items/L, respectively. Moreover, abundances of MPs in samples collected downstream of WWTPs (795 items/L in surface river water, 2142 items/kg in sediment for PWWTP, and 517 items/L, 1057 items/kg for MWWTP) consistently exceeded those of upstream (639 items/L, 926 items/kg for PWWTP, and 417 items/L, 700 items/kg for MWWTP). In addition, the discharge of treated petrochemical wastewater elevated the diversity of MPs while treated municipal wastewater elevated the relative content of narrow MPs or fibers in their downstream watersheds. In summary, treated wastewater do influence the distribution of MPs within their receiving watersheds.

Sr-Nd isotopic characteristics and their significance in provenance tracing of detrital sediment in major rivers and marginal seas of eastern China

Sr-Nd isotopic characteristics and their significance in provenance tracing of detrital sediment in major rivers and marginal seas of eastern China

A computationally efficient and fully coupled model for sediment-borne contaminant transport

The river flow, sediment transport, bed deformation and contaminant transport are strongly coupled under the impacts of climate change and anthropogenic activities. Two-dimensional (2D) mathematical models are practical tools for predicting the morphodynamic processes and contaminant transport while their computational efficiency is a key impediment to simulations featuring large scales of time and space, especially when refined meshes are required for key spot such as hydraulic structures. Therefore, a computationally efficient and fully coupled 2D model for sediment-borne contaminant transport is established under the framework of Finite Volume Method on unstructured meshes in this paper. The computing strategies of local time stepping, parallel computing and high performance clusters are employed, which can speed up the computation and reduce the run time drastically. The model is tested against three experimental cases and one idealized test case, where numerical solutions are in general agreement with the measured data and analytical solution.

Monitoring and Prevention Strategies for Iron and Aluminum Pollutants in Acid Mine Drainage (AMD): Evidence from Xiaomixi Stream in Qinling Mountains

Acid mine drainage (AMD) generated during the exploitation and utilization of mineral resources poses a severe environmental problem globally within the mining industry. The Xiaomixi Stream in Ziyang County, Shaanxi Province, is a primary tributary of the Han River, which is surrounded by historically concentrated mining areas for stone coal and vanadium ores. Rainwater erosion of abandoned mine tunnels and waste rock piles has led to the leaching of acidic substances and heavy metals, which then enter the Haoping River and its tributaries through surface runoff. This results in acidic water, posing a significant threat to the water quality of the South-to-North Water Diversion Middle Route within the Han River basin. According to this study’s investigation, Xiaomixi’s acidic water exhibits yellow and white precipitates upstream and downstream of the river, respectively. These precipitates stem from the oxidation of iron-bearing minerals and aluminum-bearing minerals. The precipitation process is controlled by factors such as the pH and temperature, exhibiting seasonal variations. Taking the Xiaomixi Stream in Ziyang County, Shaanxi Province, as the study area, this paper conducts field investigations, systematic sampling of water bodies and river sediments, testing for iron and aluminum pollutants in water, and micro-area observations using field emission scanning electron microscopy (FESEM) on sediments, along with analyzing the iron and aluminum content. The deposition is analyzed using handheld X-ray fluorescence (XRF) analyzers, X-ray diffraction (XRD), and visible–near-infrared spectroscopy data, and a geochemical model is established using PHREEQC software. This paper summarizes the migration and transformation mechanisms of iron and aluminum pollutants in acidic water and proposes appropriate prevention and control measures.

Effect of intermittent water flow on biodegradation of organic micropollutants in the hyporheic zone.

Water scarcity in the Mediterranean area has increased the number of intermittent rivers. Recently, hyporheic zones (HZ) of intermittent rivers have gained attention since a substantial part of the stream's natural purification capacity is located within these zones. Thus, understanding the flow dynamics in HZs is crucial for gaining insights into the degradation of organic micropollutants. A lab-scale study using column experiments was conducted in an attempt to elucidate the environmental processes accounting for the biodegradation capacity of the HZ under flow intermittency. A mixture of six compounds including pesticides (chloranthraniliprole, fluopyram and trifloxystrobin) and pharmaceuticals (venlafaxine, amisulpride and paroxetine) spiked at 1μg/L level was used for degradation kinetic studies and at 1mg/L for transformation products identification using suspect/non-target liquid chromatography high-resolution mass spectrometry approaches. The experiments lasted 60 days, divided into two 14-day phases: one before and one after a 5-week desiccation period. Bacterial community was charaterized by high-throughput DNA sequencing. The results suggested that intermittent flows stimulated the biodegradation of three compounds namely fluopyram, trifloxystrobin and venlafaxine, showing a large range of biodegradation profiles in batch water/sediment testing system according to OECD 308 tests. Biodegradation rate enhancement was ascribed to the occurrence of additional transformation routes after the desiccation period of river sediment, with the formation of new transformation products reported for the first time in the present work. 16S rDNA sequencing revealed that the desiccation period favored the growth of nitrifying and denitrifying bacteria which could partially explain the emergence of the new transformation pathways and most specifically those leading to N-oxide derivatives. Identification of transformation products also revealed that reductive transformation routes were relevant for this study, being dehydrogenation, dehalogenation, ether bond cleavage and sulfone reduction into sulphide important reactions. These results suggest that the intermittent flow conditions can influence the HZ biodegradation capacity.

Distinct response of nitrogen metabolism to exogenous cadmium (Cd) in river sediments with and without Cd contamination history.

The role of metal resistance on nitrogen metabolism function and community resilience against Cd is important for elucidating the evolutionary dynamics of key ecological functions in river ecosystems. In this study, the response of nitrogen transforming function to Cd exposure in river sediments from the Yangtze River Basin with varying levels of heavy metal contamination history (Cd-contaminated and Cd-free sediments) was compared to understand how Cd influenced nitrogen metabolism under varying metal resistance conditions. The results showed that chronic and persistent Cd pollution of sediments caused an elevation of transport efflux metal resistance genes (MRGs) and a reduction in the uptake MRGs, leading to a stronger tolerance to Cd for Cd-contaminated sediment than Cd-free ones. Specifically, denitrification, anaerobic ammonium oxidation (anammox) and dissimilatory nitrate reduction to ammonium (DNRA) respectively responded to Cd through different mechanisms. Exogenous Cd (5-100 mg kg-1) influenced denitrification rates (-70 %-100 % deviation to control group) by regulating key genera (Thiobacillus, Magnetospirillum, Sideroxydans etc.) and gene clusters for denitrification. Both adaptive nature of anammox bacteria and co-regulation of key genera (Candidatus_Scalindua, Candidatus_Jettenia, Planctomyces etc.) and gene hzsA were drivers of differential responses in sediments from various contamination history. Environmental factors rather than contamination history, key genera or genes were probably critical ones determining Cd-resistance in DNRA, being more tolerant to Cd in sediments with higher TOC and NH4+. Stimulation of N2O reduction process (genera Gemmatimonas and Gemmatirosa and genes nosZ) in Cd-contaminated sediments by exogenous Cd lowered N2O emission risk, whereas the reverse was true for Cd-free sediments. These results enrich our understanding about the linkages among MRGs and nitrogen reduction functions in river.

Spatial and temporal variability of physicochemical characteristics in Lancang River sediments amid hydropower development

The construction of river dams disrupts river continuity and sediment transport, altering the riverbed between sediment “sources” and “sinks” and changing the sediment characteristics of the river. In this study, 256 sediment samples from 54 major control cross-sections of the Lancang River (LCR) were analyzed to examine the spatial and temporal distribution of clay and non-clay minerals in the sediment and their relationship with the environmental changes caused by the construction 11 hydropower plants. The results indicate that the construction of terrace dams on the LCR interrupted the downstream refinement trend of sediments, which reappeared once the terrace reservoirs stabilized. Additionally, the interception of the dam increased the accumulation of clay mineral in sediments. From 2011 to 2023, the relative abundance of clay mineral in the regulated reaches (RRs) increased by 2.4 %, the quartz content decreased by 26.2 %, and the contents of calcite, mica, kaolinite, and chlorite increased, respectively. Consequently, the main non-clay mineral assemblage in the sediments shifted from quartz+feldspar to quartz+feldspar+mica. Furthermore, the clay mineral content was higher upstream the main dams (15.3 %) than downstream (14.8 %), with the sediment quartz and calcite contents being higher downstream, and mica and chlorite contents being higher upstream. The feldspar content showed a minimal change. However, the mineral composition of the sediments in individual reservoirs varied significantly, owing to the specific environmental conditions of each reservoir. The distribution of sediment clay also differed between the dry and rainy seasons. This study provides a scientific basis for managing reservoir sediment scheduling and regulating the ecological and environmental safety in watersheds.

Human health risk assessment from potentially toxic elements in the soils of Sudan: A meta-analysis.

Potentially toxic elements (PTEs) in soils threaten human health through several exposure pathways. However, health risks posed by PTEs in soils in developing countries have not yet been comprehensively investigated. Thus, such countries lack important information that is needed to implement sustainable solutions. In this study, we assessed the human health risks for 10 PTEs, including arsenic (As), cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), mercury (Hg), manganese (Mn), nickel (Ni), lead (Pb), and zinc (Zn), in Sudan focusing on soils affected by anthropogenic activities, such as industrial processes, gold mining, tannery, waste dumping, traffic (affecting roadsides), urban/rural agriculture, river, and coastal sediment land uses (LUs). For this purpose, we did a meta-analysis using 3430 PTE concentrations reported from 981 anthropogenically-affected soils in 76 publications between 1996 and 2024. Ingestion was the most common exposure pathway for both carcinogenic and non-carcinogenic PTEs. Hg and Mn were the main non-carcinogenic PTEs leading to adverse health effects in children in industrially-affected soils and coastal sediments, with average hazard quotient (HQ) and hazard index (HI) values >1. Cr and Ni caused the highest carcinogenic risk to children in all anthropogenically-affected soils as indicated by average incremental lifetime cancer risk values (ILCR >1×10-4). Further major cancer risks for children were caused by As in urban agricultural and industrial LUs, Cd in >70% of all LUs, and Pb at industrial and waste dump sites. Adults were under high cancer risks due to Cd in waste dump (ILCR=9.09×10-4) and Cr and Ni (ILCR >1×10-4) in >75% of all LUs. Cd contributed >50% and >70% to ILCR for children and adults along roadsides, respectively. Our findings can guide future research on the links between soil PTEs and human health risks in developing countries. We recommend establishing effective management strategies to reduce risks to human health based on the presence of PTEs in Sudanese soils.

Determination of neonicotinoids and related metabolite residues in river water and sediments by small-volume QuEChERS and liquid chromatography tandem mass spectrometry

Determination of neonicotinoids and related metabolite residues in river water and sediments by small-volume QuEChERS and liquid chromatography tandem mass spectrometry

Unraveling the mechanisms of post-treatment to enhance humification and Cd remediation in compost through EDTA-Fenton-Like systems.

This study aimed to enhance humification and cadmium (Cd) remediation in compost by investigating the effects of three post-treatments: ultrapure water, citric acid, and ethylenediaminetetraacetic acid disodium (EDTA). The results revealed that the EDTA post-treatment significantly enhanced humification by facilitating an EDTA-Fenton-like system within compost comprising rice straw and river sediment to remediate Cd-contaminated sediment. EDTA post-treatment not only promoted humic substances and humic acid concentrations of up to 66.30g/kg and 30.40g/kg, respectively, but also led to a reduction in the Cd content and bioavailability factor by 75.02% and 9.76%, respectively. In addition, parallel factor analysis revealed two distinct components, while two-dimensional correlation spectroscopy showed that the polysaccharides and carboxyl groups in humic acid were preferentially bound to Cd. Overall, this study proposes a promising approach for enhancing humification and Cd remediation in compost by the EDTA post-treatment.

A Review of Potentially Toxic Elements in Sediment, Water, and Aquatic Species from the River Ecosystems.

There is concern over potential toxic elements (PTEs) impacting river ecosystems due to human and industrial activities. The river's water, sediment, and aquatic life are all severely affected by the release of chemical and urban waste. PTE concentrations in sediment, water, and aquatic species from river ecosystems are reported in this review. Among the PTEs, chromium (Cr), cadmium (Cd), lead (Pb), and nickel (Ni) revealed high pollution levels in water and aquatic species (fish and shellfish) at many rivers. The Karnaphuli, Ganga, and Lee rivers have high levels of Pb and Cd contamination, while the Buriganga and Korotoa rivers' water had notable Ni contamination. A number of rivers with PTEs showed ecological risk as a consequence of the sediment's potential ecological risk (PER), the pollutant load index (PLI), and the geoaccumulation index (Igeo). A comprehensive study suggests elevated PLI values in river sediments, indicating significant pollution levels, particularly in the Buriganga River sediment, marked by high Igeo values. The PER of the Shitalakshya and Buriganga rivers was marked as very high risk, with an Eir > 320, while the Dhaleshwari and Khiru rivers showed 'high risk', with 160 = Eir < 320. It was found that fish and shellfish from the Buriganga, Turag, and Swat rivers have a high concentration of Cr. PTE pollution across several river sites could pose health toxicity risks to humans through the consumption of aquatic species. The CR value shows the carcinogenic risk to human health from eating fish and shellfish, whereas an HI value > 1 suggests no carcinogenic risk. The occurrence of other PTEs, including manganese (Mn), arsenic (As), and nickel (Ni), significantly increases the ecological risk and concerns to aquatic life and human health. This study emphasises the importance of PTE toxicity risk and continuous monitoring for the sustainability of river ecosystems.

Numerical and experimental investigation on vortex control and sedimentation suppression in a Y-shaped diversion channel with circular inlet tanks

A sudden angle change between the Y-shaped diversion channel and the inlet tank of the circular pump station often leads to boundary layer separation and large vortex formation. These flow patterns can cause significant sediment deposition in sediment-laden rivers, reducing pump efficiency. A mixture model is introduced to describe water-sediment two-phase flows. Simulation results analyze vortex characteristics and formation mechanisms, and evaluate potential sediment deposition areas. Without rectification, vortex areas cause significant sediment migration towards the sidewalls of the Y-shaped diversion channel and pump inlet. Diversion measures like sills and pressure plates are introduced to reduce flow vortices. Results show that sills generally optimize flow structures. Sills in the main Y-shaped diversion channel outperform those in other channels in terms of optimization. Pressure plates also optimize flow structures. Vortex structure and position are closely related to the distance between the pressure plate and the circular intake tank. Optimized measures with pressure plates significantly reduce the flow deviation angle and improve flow velocity uniformity. Numerical simulation accuracy is validated through experiments. Results reveal the formation mechanism of adverse vortices and their sedimentation effects, which are detrimental to pump stations. The proposed rectification scheme provides theoretical support for optimizing pump station operation.

Prevalence, diversity, and antimicrobial resistance of Salmonella spp. isolated from river sediments in Northwest Mexico.

Salmonella is a major foodborne pathogen widely distributed in the environment. Surface water, soil, and sediments may confer a protective effect on Salmonella against non-host conditions. This study focused on determining the prevalence of Salmonella spp. in river sediments from Sinaloa central region by the Most Probable Number (MPN) technique and determining the antimicrobial resistance profile by Kirby-Bauer assay. Results showed the prevalence of Salmonella from 37.5 to 62.5% of the samples, oscillating from 0.322 to 20 MPN/4g, with August being the month with the highest levels. In silico geno-serotyping reveals the presence of Salmonella serotypes Typhi, Javiana, Ohio, Montevideo, Oranienburg, Pomona, Agona, Livingstone, Weltevreden, Anatum, and Minnesota. The most prevalent serotypes in river sediments were Pomona, Montevideo, and Oranienburg. Almost all isolates showed resistance to erythromycin, rifampin, and penicillin. This study reveals the prevalence and distribution of Salmonella enterica in river sediments, which may represent a potential niche for establishment and survival in the environment and become a potential contamination source.

Environmental Implications of Sand Harvesting. Insights from Archer’s Post, Samburu County.

Sand harvesting is identified as a common socio economic activity, which is practiced globally, regionally and locally. In accordance with this understanding, this study seeks to assess and find out the key factors that have led to increase in sand extraction, and environmental implications of sand extraction in Archer’s’ Post, Samburu County. The sampling technique employed in the study involved both probabilistic (stratified and simple random sampling) and non-probabilistic (purposive sampling). A target population of 135 individuals from local residents, sand harvesters (sand miners, sand loaders, and sand transporters), chiefs, officers from Ministry of Land and NEMA offices. Questionnaires and key informant interview schedules were used to obtain data and observation while the data was analyzed by using statistical software such as SPSS and Microsoft Excel. The results were highlighted by bar graphs, tables and pie charts The survey findings were summarized using bar graphs, tabulation and pie charts. From the study it was established that sand mining in Archer’s Post is largely as a result of desperate need for an income source, need for construction materials form infrastructure and other development needs and generally a sheer economic force. Such environmental impacts include soil erosion, change of vegetation cover, and reduced water quality as a result of sedimentation in the local rivers and streams. These effects have been seen to negatively affect agriculture, diversity of species and the eco-system in the region. The study also revealed gaps of the current regulations, which do not provide an effective mechanism for the management and minimization of the environmental impacts of sand extraction. Some of the issues that are worthy of mention and solved in the near future for a sustainable sand harvesting scheme include the weak civil society involvement and engagement in environmental management, limited compliance with the set laws, and substandard harvesting techniques, as well as insufficient funding of monitoring and restoration programs. The results suggest that there be improvement in practices that will reduce the impact of sand mining on the environment.

Determination of river flow and sediment regime changes in response to construction of regulating dams: an indicator-based approach

Determination of river flow and sediment regime changes in response to construction of regulating dams: an indicator-based approach

Change in sediment transport regime of the Keelung River in Taiwan induced by the operation of Yuanshantze flood diversion tunnel.

The impact of flood diversion channels on river sediment transport has been rarely reported. This study uses the Yuanshantze flood diversion tunnel (YFDT), which was commissioned in July 2005 in Taiwan, as an example. This study calculates the sediment transport in the Keelung River from 1997 to 2018 by using seasonal rating curves, in the form of aQb. Changes in rating curve coefficients are also analyzed to understand the impact of YFDT on sediment transport regime. The results show that after the construction of YFDT, the annual sediment transport dropped from 0.59 ± 0.47 [Mt y-1] to 0.17 ± 0.09 [Mt y-1], leading to dampened inter- and intra-annual variation. Before flood diversion, the Keelung River requires ~1% cumulative time to export 50% cumulated sediment loads, but it takes ~4.5% cumulative time after flood diversion. Exponent b decreased from 1.23±0.18 to 1.15±0.13, and log a decreased from 0.71±0.15 to 0.51±0.11, suggesting that the Keelung River is akin to a different river in terms of sediment transport regime. While the design of the diversion tunnel mainly considered its impact on flow, its impact on sediment transport is far greater than its impact on flow and should not be overlooked. Whether this new normality will affect the downstream river continuum requires continuous attention.