Analysis on biomass and productivity of epilithic algae and their relations to environmental factors in the Gufu River basin, Three Gorges Reservoir area, China

Ge, J.; Wu, Shoujun; Touré, Dado; Cheng, La-Mei; Miao, Wenjie; Cao, Huafen; Pan, Xiaoying; Li, Jianfeng; Yao, Minmin; Feng, Liang

doi:10.1007/s11356-015-4112-8

Cited by 8 publications

(3 citation statements)

References 31 publications

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“…When it is below 0.19 m 3 /s, the SD decreases while the RW proportion increases. The main reason for these results is that, under these conditions, algae growth is affected by a combination of factors such as nutrient concentration, nutrients, water flow velocity, and the diluting effect of water change in the water body [20,21,40].…”

Section: Changes In Water Quality Under Various Replenishment Conditionsmentioning

confidence: 99%

Simulation Study on the Optimisation of Replenishment of Landscape Water with Reclaimed Water Based on Transparency

Wei

Pei

et al. 2023

IJERPH

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Water-scarce cities have fewer surface water (SW) resources available for ecological use, causing landscape water to deteriorate due to water shortage and fail to perform their intended landscape functions. As a result, many cities use reclaimed water (RW) to replenish them. However, this could cause concern among the people, as RW usually has higher nutrient concentrations, which may stimulate algae growth and deteriorate the aesthetic senses of the receiving water bodies. In order to assess the feasibility of using RW for this purpose, this study used Xingqing Lake in Northwest China as insight into the effect of RW replenishment on the visual landscape quality of urban landscape water. Water transparency (measured by SD) is used as an intuitive indicator to reflect the comprehensive influence of suspended solids and algae growth on the water’s aesthetic quality. Scenario analyses were carried out after calibrating and validating one-year data in MIKE 3 software with both SD and algae growth calculations, and the results showed that the low concentration of suspended matter in RW could compensate for the decrease in SD due to algal blooms caused by high concentrations of nitrogen and phosphorus, and the effect on SD is especially pronounced under conditions that are not conducive to algal growth, such as good flow conditions and low temperature. In addition, to meet a SD ≥ 70 mm, the total water inflow required can be significantly reduced with the optimal application of RW. It is also indicated that partial or complete utilization of RW to replace SW for replenishing the landscape water could be feasible from the viewpoint of landscape quality, at least for the landscape water investigated in this study. This can provide a method for the improvement to urban water management practices by using RW for replenishment in water-scarce cities.

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Section: Changes In Water Quality Under Various Replenishment Conditionsmentioning

confidence: 99%

Simulation Study on the Optimisation of Replenishment of Landscape Water with Reclaimed Water Based on Transparency

Wei

Pei

et al. 2023

IJERPH

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“…The utilization of seismic data for zonation studies in buried hills mainly focuses on pre-drilling predictions; however, due to limitations in existing seismic data quality and complexities associated with fracture development within these formations, predicting favorable reservoirs often yields multiple solutions. Furthermore, numerous scholars have conducted a comprehensive evaluation of the buried hill development model using geological data such as core samples, thin sections, and well logging data [8,9]. Wang Deying et al extensively employed various experimental methods, including core analysis, X-ray diffraction, scanning electron microscopy, conventional physical properties testing, zircon dating, mineral dissolution simulation, statistical analysis methods to investigate the geological characteristics, genetic mechanisms, and a development model of gneiss weathering crust reservoirs in the Bohai Sea [2,10,11].…”

Section: Introductionmentioning

confidence: 99%

Prediction Technology of a Reservoir Development Model While Drilling Based on Machine Learning and Its Application

Wang,

Mao,

Yang

et al. 2024

Processes

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In order to further understand the complex spatial distribution caused by the extremely strong heterogeneity of buried hill reservoirs, this paper proposes a new method for predicting the development pattern of buried hill reservoirs based on the traditional pre-drilling prediction and post-drilling evaluation methods that mainly rely on seismic, logging, and core data, which are difficult to meet the timeliness and accuracy of drilling operations. Firstly, the box method and normalization formula are used to process and normalize the abnormal data of element logging and engineering logging, and then the stepwise regression analysis method is used to optimize the sensitive parameters of element logging and engineering logging. The Light Gradient Boosting Machine (LightGBM) algorithm, deep neural network (DNN), and support vector machine (SVM) are used to establish a new method for predicting the development pattern of buried hill reservoirs. Lastly, a comprehensive evaluation index F1 score for the model is established to evaluate the prediction model for the development pattern of buried hill reservoirs. The F1 score value obtained from this model’s comprehensive evaluation index indicates that the LightGBM model achieves the highest accuracy, with 96.7% accuracy in identifying weathered zones and 95.8% accuracy in identifying interior zones. The practical application demonstrates that this method can rapidly and accurately predict the development mode of buried hill reservoirs while providing a new approach for efficient on-site exploration and decision-making in oil and gas field developments. Consequently, it effectively promotes exploration activities as well as enhances the overall process of oil and gas reservoir exploration.

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“…Several dams are used for flood mitigation as well . On the other hand, controlling a dam critically affects its downstream river environment because the original flow regime is altered . Sediment transport and attached algae population dynamics in dam downstream experience significant changes because dams trap sediment and the algae growth is highly flow‐dependent .…”

Section: Introductionmentioning

confidence: 99%

Modeling stochastic operation of reservoir under ambiguity with an emphasis on river management

Yoshioka

2019

Optim Control Appl Methods

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An optimization problem of controlling a dam installed in a river is analyzed based on a stochastic control formalism of a diffusion process under model ambiguity: a new mathematical approach to this issue. The diffusion process is a pathwise unique solution to a water balance equation considering the inflow, outflow, water loss in the reservoir, and direct rainfall. Finding the optimal reservoir operation policy reduces to solving a degenerate parabolic partial differential equation: a Hamilton-Jacobi-Bellman-Isaacs equation. A monotone finite difference scheme is constructed for discretization of the equation, successfully generating nonoscillatory and reasonably accurate numerical solutions. Stability analysis of the resulting water balance dynamics is finally carried out for both environmentally friendly and not friendly reservoir operations. KEYWORDS finite difference scheme, Hamilton-Jacobi-Bellman-Isaacs equation, reservoir operation, stochastic control, viscosity solution INTRODUCTIONThis paper contributes to providing a mathematical framework for modeling and control of reservoirs created in rivers.Since the problem has an engineering background, it is first presented, and then, the issues to be addressed and our contributions are explained.Many rivers have dams serving as central infrastructures to supply essential water resources for human lives. 1-3 The stored water in the reservoir created by a dam is utilized for multiple purposes, such as drinking water, irrigation, and hydropower generation. 4 Several dams are used for flood mitigation as well. 5,6 On the other hand, controlling a dam critically affects its downstream river environment because the original flow regime is altered. 7-9 Sediment transport and attached algae population dynamics in dam downstream experience significant changes because dams trap sediment and the algae growth is highly flow-dependent. 10 Dam operation is thus desired to be environmentally friendly such that its impacts on the downstream are minimized, while it should be fit-for-purpose at the same time.Management of environment and ecology in rivers has been a long-standing engineering problem, 11-13 and mathematical tools and concepts for their modeling, analysis, and control are still developing. Several researchers considered river management problems based on stochastic process models such as stochastic differential equations (SDEs) 14 that can naturally consider stochasticity involved in environmental and ecological processes. 15 Interactions between aquatic species, such as riparian vegetation and fishes, and river discharges have been described with SDEs. 16 Miyamoto and Kimura 17 analyzed seedling, growth, and mortality dynamics of riparian trees subject to stochastic flood disturbances. Vesipa et al 18 764

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Analysis on biomass and productivity of epilithic algae and their relations to environmental factors in the Gufu River basin, Three Gorges Reservoir area, China

Cited by 8 publications

References 31 publications

Simulation Study on the Optimisation of Replenishment of Landscape Water with Reclaimed Water Based on Transparency

Simulation Study on the Optimisation of Replenishment of Landscape Water with Reclaimed Water Based on Transparency

Prediction Technology of a Reservoir Development Model While Drilling Based on Machine Learning and Its Application

Modeling stochastic operation of reservoir under ambiguity with an emphasis on river management

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