Enhancing machine learning models for total organic carbon prediction by integrating geospatial parameters in river watersheds

The Science of The Total Environment, Год журнала: 2024, Номер 943, С. 173743 - 173743

Опубликована: Июнь 6, 2024

Язык: Английский

---

Modelling the Influence of Riverine Inputs on the Circulation and Flushing Times of Small Shallow Estuaries

Estuaries and Coasts, Год журнала: 2020, Номер 44(1), С. 54 - 69

Опубликована: Июль 1, 2020

Abstract Simple flushing time calculations for estuarine systems can be used as proxies eutrophication susceptibility. However, more complex methods are required to better understand entire systems. Understanding of the hydrodynamics driving circulation and times in small, eutrophic, temperate estuaries is less advanced than larger counterparts due lack data difficulties accurately modelling small-scale This paper uses microtidal Christchurch Harbour estuary Southern UK a case study elucidate physical controls on susceptibility small shallow basins. A depth-averaged hydrodynamic model has been configured investigate processes with particular emphasis understanding impact riverine inputs this system. Results indicate control changes from tidally fluvially driven increase. Flushing times, calculated using particle tracking method, that system take long 132 h flush when river flow low, or short 12 input exceptionally high. When total into 30 m 3 s −1 , tidal flux dominant control, which results high during neap tides. Conversely, greater fluvial flux, spring tides longer at neaps. The methodology presented here shows spatial scales possible but highlights importance determine variability across

Язык: Английский

---

Short-term effects of very heavy rainfall events on the water quality of a shallow coastal lagoon

Hydrobiologia, Год журнала: 2021, Номер unknown

Опубликована: Дек. 8, 2021

Язык: Английский

---

Changes in the Dissolved Organic Matter Characteristics Released from Sediment According to Precipitation in the Namhan River with Weirs: A Laboratory Experiment

International Journal of Environmental Research and Public Health, Год журнала: 2022, Номер 19(9), С. 4958 - 4958

Опубликована: Апрель 19, 2022

In this study, changes in the properties of dissolved organic matter (DOM) released from sediments into water layers were investigated. To analyze spatial and temporal variation carbon (DOC), sediment bottom samples collected upstream Gangcheon, Yeoju, Ipo weirs Namhan River during rainy non-rainy seasons. The initial DOC was correlated with precipitation (R2 = 0.295, p 0.034) residence time 0.275, 0.040). change concentration resulted sediments, which may cause quality issues water. fluorescence analysis revealed that DOM contained higher levels hydrophilic low-molecular-weight (LMW) season hydrophobic high-molecular-weight (HMW) season. Since is main resource drinking for Seoul metropolitan area, our results can help to optimize treatment process by reflecting characteristics vary Furthermore, statistical confirmed nutrient content pore-water be used estimate release rate layer. study provide a better understanding movement aquatic ecosystems influences rainfall on surface waterbody.

Язык: Английский

---

Strong Precipitation and Human Activity Spur Rapid Nitrate Deposition in Estuarine Delta: Multi-Isotope and Auxiliary Data Evidence

International Journal of Environmental Research and Public Health, Год журнала: 2021, Номер 18(12), С. 6221 - 6221

Опубликована: Июнь 8, 2021

The intensive development of the Yellow River Delta has caused huge transportation non-point pollutants into Bohai Sea through source river estuaries and thus poses a considerable threat to eco-environmental security in region. Long-term irrigation basin, with occasional heavy rainfall related effects ensuring hydrological processes human activities terms nitrate N transport via surface water systems, is unclear. Using stable isotope (δ2H-H2O δ18O-H2O, δ15N-NO3− δ18O-NO3−) auxiliary geographic data, ISO model was run quantitatively analyze supply relationship systems rapid change spatial pattern due estuarine delta. This analysis made clear dominant contribution agricultural urbanization NO3−-N emission, on which basis refined management measures were proposed deal NO3− from “source-process”. results study show that: (1) replenishment affected not only by rainfall, irrigation, other conservancy but also proportion flow declined estuary; (2) To certain extent, diluted concentration increased instantaneous flux sea, where continuously upstream downstream; (3) deposition estuary delta driven such as excessive use nitrogen fertilizers, urbanization, livestock waste discharge, and; (4) Scientific needed realize interactive effect output carrying absorption capacity coastal fragile ecosystems exogenous inputs.

Язык: Английский

---

Fluorophores in surface freshwaters: importance, likely structures, and possible impacts of climate change

Environmental Science Processes & Impacts, Год журнала: 2021, Номер 23(10), С. 1429 - 1442

Опубликована: Янв. 1, 2021

Fluorescence spectroscopy is very useful for the characterisation of organic matter in natural water samples. The importance protein-like fluorescence might be enhanced by several events induced warming waters such as lake water.

Язык: Английский

---

Effect of damming on hydrogeochemical characteristics and potential environmental risks in a large reservoir: Insights from different vertical layer sampling

Environmental Research, Год журнала: 2023, Номер 239, С. 117365 - 117365

Опубликована: Окт. 13, 2023

Язык: Английский

---

Phytoplankton in headwater streams: spatiotemporal patterns and underlying mechanisms

Frontiers in Plant Science, Год журнала: 2023, Номер 14

Опубликована: Окт. 24, 2023

Phytoplankton are key members of river ecosystems wherein they influence and regulate the health local environment. Headwater streams subject to minimal human activity serve as sources rivers, generally exhibiting pollution strong hydrodynamic forces. To date, characteristics phytoplankton communities in headwater have remained poorly understood. This study aims address this knowledge gap by comparing with those plain rivers. The results demonstrated that within similar watershed sizes, lower levels spatiotemporal variability were observed respect community compared Lower nutrient hydrodynamics contribute growth limitation these streams, thereby reducing variation. However, conditions additionally greater diversity consequent succession towards Cyanophyta . Overall, provide new insights into dynamics stream support efforts for their ecological conservation.

Язык: Английский

---

A methodology for integrating time-lagged rainfall and river flow data into machine learning models to improve prediction of quality parameters of raw water supplying a treatment plant

Journal of Hydroinformatics, Год журнала: 2023, Номер 25(6), С. 2406 - 2426

Опубликована: Ноя. 1, 2023

Abstract Rainfall and increased river flow can deteriorate raw water (RW) quality parameters such as turbidity UV absorbance at 254 nm. This study aims to develop a methodology for integrating both time-lagged watershed rainfall data into machine learning models of the RW supplying drinking treatment plant (DWTP). Spearman's rank non-parametric cross-correlation analyses were performed using rain in from intake. Then, UV254 modelled, support vector regression (SVR) an artificial neural network (ANN) under several prediction scenarios with variables. River presented very strong correlation quality, whereas showed moderate correlation. Time lags maximum correlations between few hours, while UV254, they 2 4 days, demonstrating varied time complex behaviour. The best performing scenario was one that used input data. ANN better than SVR. Results this suggest possibility new modelling strategies more accurate chemical dosing removal key contaminants.

Язык: Английский

---

Rapid Loss of Dissolved CO2 From a Subtropical Steep Headwater Stream

Frontiers in Earth Science, Год журнала: 2021, Номер 9

Опубликована: Ноя. 1, 2021

High-gradient headwater streams are major participants in the carbon (C) cycle because of their capabilities emitting a significant amount dioxide (CO 2 ). Notwithstanding, CO emissions have been largely overlooked previous studies owing to small water surface area and sometimes strenuous be measured narrow channel widths strong turbulence. This study examined spatial seasonal variabilities dynamics subtropical steep stream fed by groundwater. Our found that pH dissolved oxygen exhibited general increasing trend away from source whereas partial pressure (pCO ) showed downward trend. The pCO upper reach was higher than ambient level 19–114 times, with an average drop >70% at just 9.2 m groundwater source, demonstrating potentially large emission into atmosphere within this short distance. Additionally, sampling works conducted further downstream revealed derived could almost completely dissipate approximately half kilometer source. concentrations organic were also lower during period air temperatures stream, indicating temperature-dependent metabolism decomposition matter soil might modulate C although rapid gas exchange along remained determinative factor. findings reassert essential disregarding them greenhouse inland waters would underestimate potency influence global cycle.

Язык: Английский

---