Journal of Hydro-environment Research最新文献

筛选
英文 中文
Unsteady shallow meandering flows in rectangular reservoirs: A modal analysis of URANS modelling 矩形水库中的非定常浅曲流——URANS模型的模态分析
IF 2.8 3区 环境科学与生态学
Journal of Hydro-environment Research Pub Date : 2022-05-01 DOI: 10.1016/j.jher.2022.03.002
Daniel Valero , Daniel B. Bung , Sebastien Erpicum , Yann Peltier , Benjamin Dewals
{"title":"Unsteady shallow meandering flows in rectangular reservoirs: A modal analysis of URANS modelling","authors":"Daniel Valero ,&nbsp;Daniel B. Bung ,&nbsp;Sebastien Erpicum ,&nbsp;Yann Peltier ,&nbsp;Benjamin Dewals","doi":"10.1016/j.jher.2022.03.002","DOIUrl":"10.1016/j.jher.2022.03.002","url":null,"abstract":"<div><p>Shallow flows are common in natural and human-made environments. Even for simple rectangular shallow reservoirs, recent laboratory experiments show that the developing flow fields are particularly complex, involving large-scale turbulent structures. For specific combinations of reservoir size and hydraulic conditions, a meandering jet can be observed. While some aspects of this pseudo-2D flow pattern can be reproduced using a 2D numerical model, new 3D simulations, based on the unsteady Reynolds-Averaged Navier-Stokes equations, show consistent advantages as presented herein. A Proper Orthogonal Decomposition was used to characterize the four most energetic modes of the meandering jet at the free surface level, allowing comparison against experimental data and 2D (depth-averaged) numerical results. Three different isotropic eddy viscosity models (RNG <em>k-ε</em>, <em>k-ε</em>, <em>k-ω</em>) were tested. The 3D models accurately predicted the frequency of the modes, whereas the amplitudes of the modes and associated energy were damped for the friction-dominant cases and augmented for non-frictional ones. The performance of the three turbulence models remained essentially similar, with slightly better predictions by RNG <em>k-ε</em> model in the case with the highest Reynolds number. Finally, the Q-criterion was used to identify vortices and study their dynamics, assisting on the identification of the differences between: i) the three-dimensional phenomenon (here reproduced), ii) its two-dimensional footprint in the free surface (experimental observations) and iii) the depth-averaged case (represented by 2D models).</p></div>","PeriodicalId":49303,"journal":{"name":"Journal of Hydro-environment Research","volume":"42 ","pages":"Pages 12-20"},"PeriodicalIF":2.8,"publicationDate":"2022-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43839123","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
引用次数: 0
Estimation of actual evapotranspiration and water stress in the Lijiang River Basin, China using a modified Operational Simplified Surface Energy Balance (SSEBop) model 基于改进的SSEBop模型估算丽江流域实际蒸散发和水分胁迫
IF 2.8 3区 环境科学与生态学
Journal of Hydro-environment Research Pub Date : 2022-03-01 DOI: 10.1016/j.jher.2022.01.003
Yuefeng Yao , Azim U. Mallik
{"title":"Estimation of actual evapotranspiration and water stress in the Lijiang River Basin, China using a modified Operational Simplified Surface Energy Balance (SSEBop) model","authors":"Yuefeng Yao ,&nbsp;Azim U. Mallik","doi":"10.1016/j.jher.2022.01.003","DOIUrl":"10.1016/j.jher.2022.01.003","url":null,"abstract":"<div><p>Due to the simultaneous impacts of economic development and climate change, the Lijiang River Basin in China—the largest karst tourist attraction in the world—has experienced dramatic water shortages during the dry season. As actual evapotranspiration (<span><math><msub><mrow><mi>ET</mi></mrow><mi>a</mi></msub></math></span>) plays a critical role in the water cycle, accurate estimation of <span><math><msub><mrow><mi>ET</mi></mrow><mi>a</mi></msub></math></span> and water stress are important for sustainable water resources management. In this paper, we mapped the distribution of daily <span><math><msub><mrow><mi>ET</mi></mrow><mi>a</mi></msub></math></span> using a modified Operational Simplified Surface Energy Balance (SSEBop) model in combination with Landsat 8 images and assessed water stress using the Crop Water Stress Index (CWSI) during the dry season in the Lijiang River Basin. In general, the daily <span><math><msub><mrow><mi>ET</mi></mrow><mi>a</mi></msub></math></span> simulated by the SSEBop model with aerodynamic resistance value of 110 s m<sup>−1</sup> was higher than that of satellite-based actual evapotranspiration products (i.e., MOD16A2 and Penman-Monteith-Leuning (PML)_V2 actual evapotranspiration products in this study). Aerodynamic resistance plays a critical role in the estimation of energy fluxes in the SSEBop model and should be readjusted and calibrated with available datasets to improve the model’s performance in estimating actual evapotranspiration for particular regions. Readjusted values between 20 and 35 s m<sup>−1</sup> of aerodynamic resistance produced reasonable agreement with satellite-based actual evapotranspiration products in the Lijiang River Basin. In addition, insufficient ground-level measurements of actual evapotranspiration might have increased the uncertainty of the SSEBop model’s performance. The achievement of higher accuracy in the estimation of actual evapotranspiration and water availability will require establishing local flux towers, particularly in forested areas, to collect evapotranspiration, temperature and other in situ data. For different land-cover classes, forest areas exhibited the highest actual evapotranspiration, whereas farmland and built-up areas had the lowest actual evapotranspiration values compared to the other land-cover classes. All land-cover classes, especially farmland areas, experienced severe water stress. Inadequate precipitation as a result of climate change, combined with high actual evapotranspiration will result in less water being available for the Lijiang River Basin. Additional water is required to compensate for evapotranspiration and support plant growth in the Lijiang River Basin during the growing season.</p></div>","PeriodicalId":49303,"journal":{"name":"Journal of Hydro-environment Research","volume":"41 ","pages":"Pages 1-11"},"PeriodicalIF":2.8,"publicationDate":"2022-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44182196","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
引用次数: 0
Impact of renewed solar dimming on streamflow generation in monsoon dominated tropical river basins 太阳再次变暗对季风主导的热带河流流域水流生成的影响
IF 2.8 3区 环境科学与生态学
Journal of Hydro-environment Research Pub Date : 2022-03-01 DOI: 10.1016/j.jher.2022.02.002
Pramod Soni , Shivam Tripathi , Rajesh Srivastava
{"title":"Impact of renewed solar dimming on streamflow generation in monsoon dominated tropical river basins","authors":"Pramod Soni ,&nbsp;Shivam Tripathi ,&nbsp;Rajesh Srivastava","doi":"10.1016/j.jher.2022.02.002","DOIUrl":"10.1016/j.jher.2022.02.002","url":null,"abstract":"<div><p><span>From 1950s to 1980s, various observational studies<span><span> around the globe found a significant decrease in surface solar radiation (SSR), which reversed in late 1980s for most of the countries including India. SSR observations at 12 stations located across India revealed that a much stronger dimming has reappeared during the last decade (2006–2015) after a brightening during 1996–2005. In the present study, effects of renewed solar dimming on actual evapotranspiration and runoff were analyzed using a semi-distributed </span>hydrological model, Soil and Water Assessment Tool (SWAT) in 24 river basins (ranging from 1260 to 40000 km</span></span><sup>2</sup><span>) located in peninsular India. For these river basins, calibration (2003–2009) and validation (2010–2014) were performed using the observed daily discharge data, obtained from water resources information system (WRIS) of India, with a 3 year warm up period (2000–2002). The sequential uncertainty domain parameter fitting algorithm (SUFI-2) of SWAT-CUP (calibration and uncertainty program) was used with modified Nash–Sutcliffe efficiency (MNS) as the objective function to calibrate 13 model parameters, which can potentially affect streamflow. In nearly all the river basins, the p- and r-factor of 95 percentage prediction uncertainty (PPU) were more than 0.7 and less than 1, respectively. At daily timescale, MNS values were more than 0.5 in most of the river basins, reaching up to 0.66 and 0.71 during calibration and validation periods, respectively. Calibrated model was used to analyze the water balance of these river basins and different sets of experiments (with observed SSR trends) were performed to find SSR impacts on it. The model was simulated with and without the observed declines in SSR trends. The average change in SSR (in terms of evaporation equivalent) was −267.93 ± 100.92 mm/day/year (−5.62 ± 2.12%) with maximum reaching up to −417.12 mm/day/year (−8.99%). Due to this SSR change, actual evaporation was reduced resulting in 18.97 ± 9.78 mm/day/year (4.13 ± 2.50%) change in percolation. The percolation changes were higher for river basins having areas covered by forests and cropland/woodland, and having loam and sandy-clay soils. The increase in runoff generated was 6.90 ± 3.42 mm/day/year (2.14 ± 1.58%) with a maximum of 15.25 mm/day/year (7.56%) whereas corresponding increase in streamflow was found to be 9.93 ± 5.27 mm/day/year(4.21 ± 2.38%) with a maximum of 26.71 mm/day/year (11.86 %). The study reveals that the recent observed SSR changes are significant enough to have resulted in increased streamflow in the monsoon dominated tropical river basins of India.</span></p></div>","PeriodicalId":49303,"journal":{"name":"Journal of Hydro-environment Research","volume":"41 ","pages":"Pages 12-24"},"PeriodicalIF":2.8,"publicationDate":"2022-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41386338","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
引用次数: 0
Wave attenuation by multiple slotted barriers with a zig-zag arrangement -A physical and numerical approach 锯齿形排列的多个开槽屏障对波浪的衰减——一种物理和数值方法
IF 2.8 3区 环境科学与生态学
Journal of Hydro-environment Research Pub Date : 2022-03-01 DOI: 10.1016/j.jher.2022.02.001
V. Kumaran , S. Neelamani , K.G. Vijay , N. Al-Anjari , A. Al-Ragum
{"title":"Wave attenuation by multiple slotted barriers with a zig-zag arrangement -A physical and numerical approach","authors":"V. Kumaran ,&nbsp;S. Neelamani ,&nbsp;K.G. Vijay ,&nbsp;N. Al-Anjari ,&nbsp;A. Al-Ragum","doi":"10.1016/j.jher.2022.02.001","DOIUrl":"10.1016/j.jher.2022.02.001","url":null,"abstract":"<div><p>In the present study, scattering of surface gravity waves by multiple slotted vertical barriers arranged in a zig-zag manner is analyzed by employing Computational Fluid Dynamics (CFD) and validated with physical model tests. The porosity of the vertical slotted barrier is varied from 10% to 40%, and the number of slotted barriers varied from 1 to 6. The results from CFD correlate well with the laboratory measurements on the scattering coefficients for a wide range of input conditions giving a high level of confidence. For relatively short waves (<span><math><mrow><mi>h</mi><mo>/</mo><mi>λ</mi></mrow></math></span> &gt; 0.3, <span><math><mrow><mi>h</mi></mrow></math></span>- water depth and <span><math><mrow><mi>λ</mi></mrow></math></span>- wave length), slotted barriers up to 3 numbers and porosity from 20% to 30% are required to achieve wave transmission coefficient in the range of 0.2 to 0.3. For relatively long waves (<span><math><mrow><mi>h</mi><mo>/</mo><mi>λ</mi></mrow></math></span> &lt; 0.3), slotted barriers of 5 to 6 numbers and porosity in the range of 10% to 20% are needed to obtain wave transmission of 0.2 to 0.3. The results presented in this study can be used for a wide range of wave damping applications in the field of coastal engineering.</p></div>","PeriodicalId":49303,"journal":{"name":"Journal of Hydro-environment Research","volume":"41 ","pages":"Pages 25-37"},"PeriodicalIF":2.8,"publicationDate":"2022-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49290887","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
引用次数: 2
Three different models to evaluate water discharge: An application to a river section at Vinh Tuy location in the Lo river basin, Vietnam 评估排水量的三种不同模型:在越南洛河流域永都河段的应用
IF 2.8 3区 环境科学与生态学
Journal of Hydro-environment Research Pub Date : 2022-01-01 DOI: 10.1016/j.jher.2021.12.002
Chien Pham Van, Giang Nguyen–Van
{"title":"Three different models to evaluate water discharge: An application to a river section at Vinh Tuy location in the Lo river basin, Vietnam","authors":"Chien Pham Van,&nbsp;Giang Nguyen–Van","doi":"10.1016/j.jher.2021.12.002","DOIUrl":"10.1016/j.jher.2021.12.002","url":null,"abstract":"<div><p>This study presents three different models, namely power-law rating curve, one-dimensional lateral distribution method (1D–LDM), and gated recurrent network (GRU) model that can be applied to evaluate water discharge from water surface elevation time-series in a river cross-section for a long time period. A river section at Vinh Tuy location on the Lo river basin (Vietnam) is used to demonstrate the models. Appropriate values of modelling parameters are carefully determined using (i) the daily observed discharge values collected in the period from 2012 to 2018 and (ii) five error estimates for quantitatively assessing the agreement between estimated and observed water discharges. The results showed that all three models reproduced very well the observed discharge values, with root mean square error and mean absolute error, as well as mean error of discharge, are only about 5.5% of the maximum value of discharge monitoring in the studied cross-section, while Nash–Sutcliffe efficiency and Pearson’s correlation coefficient are greater than 0.89. The models are then applied to evaluate discharge values in the studied cross-section for the period from 1972 to 2011, revealing that statistical indicators, i.e. mean value, standard derivation, and covariance of estimated water discharge, are consistent with those obtained from the observations. Among three investigated models, the GRU model was finally proved to be the best one, providing even better results than the 1D-LDM and power-law rating curve.</p></div>","PeriodicalId":49303,"journal":{"name":"Journal of Hydro-environment Research","volume":"40 ","pages":"Pages 38-50"},"PeriodicalIF":2.8,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49368497","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
引用次数: 1
Simulation of energy dissipation downstream of labyrinth weirs by applying support vector regression integrated with meta-heuristic algorithms 支持向量回归与元启发式算法相结合模拟迷宫堰下游消能
IF 2.8 3区 环境科学与生态学
Journal of Hydro-environment Research Pub Date : 2022-01-01 DOI: 10.1016/j.jher.2021.12.003
Amin Mahdavi-Meymand, Wojciech Sulisz
{"title":"Simulation of energy dissipation downstream of labyrinth weirs by applying support vector regression integrated with meta-heuristic algorithms","authors":"Amin Mahdavi-Meymand,&nbsp;Wojciech Sulisz","doi":"10.1016/j.jher.2021.12.003","DOIUrl":"10.1016/j.jher.2021.12.003","url":null,"abstract":"<div><p><span>In this study, multi-tracker optimization algorithm (MTOA), particle swarm<span> optimization (PSO), and differential evolution (DE) algorithms were integrated with support vector regression (SVR) to predict energy dissipation downstream of labyrinth weirs (Δ</span></span><em>E</em><span>). In order to evaluate the performance of these methods, the results are compared with corresponding outcome obtained by applying two other methods, namely, multilayer perceptron neural network (MLPNN) and multiple linear regressions methods (MLR). The input parameters comprise the discharge, the upstream flow depth, the crest length of a single cycle of the labyrinth weir, the width of a single cycle of the labyrinth weir, the apex width, the number of labyrinth weir cycles, the sidewall angle, and the height of weir. The results indicate that the meta-heuristic algorithms substantially improve the performance of SVR. The results show that the integrative methods, SVR-MTOA, SVR-PSO, and SVR-DE, are more accurate than the MLPNN and the MLR. In average, the integrative methods provide 39.63% more accurate results than the MLPNN and 79.34% more accurate results than the MLR. The average RMSE and </span><em>R<sup>2</sup></em> for the integrative methods are 0.0054 m and 0.977, respectively. Among all integrative methods, the SVR-MTOA yields the best results, with <em>RMSE</em> = 0.0044 m and <em>R<sup>2</sup></em> = 0.986.</p></div>","PeriodicalId":49303,"journal":{"name":"Journal of Hydro-environment Research","volume":"40 ","pages":"Pages 91-101"},"PeriodicalIF":2.8,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49461966","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
引用次数: 2
Climate change impact on water quality in the integrated Mahabad Dam watershed-reservoir system 气候变化对Mahabad坝流域-水库综合系统水质的影响
IF 2.8 3区 环境科学与生态学
Journal of Hydro-environment Research Pub Date : 2022-01-01 DOI: 10.1016/j.jher.2021.12.001
Mohammad Nazari-Sharabian , Masoud Taheriyoun
{"title":"Climate change impact on water quality in the integrated Mahabad Dam watershed-reservoir system","authors":"Mohammad Nazari-Sharabian ,&nbsp;Masoud Taheriyoun","doi":"10.1016/j.jher.2021.12.001","DOIUrl":"10.1016/j.jher.2021.12.001","url":null,"abstract":"<div><p>Climate change, besides global warming, is expected to intensify the hydrological cycle, which can impact watershed nutrient yields and affect water quality in the receiving water bodies. The Mahabad Dam Reservoir in northwest Iran is a eutrophic reservoir due to excessive watershed nutrient input, which could be exacerbated due to climate change. In this regard, a holistic approach was employed by linking a climate model (CanESM2), watershed-scale model (SWAT), and reservoir water quality model (CE-QUAL-W2). The triple model investigates the cumulative climate change effects on hydrological parameters, watershed yields, and the reservoir’s water quality. The SDSM model downscaled the output of the climate model under moderate (RCP4.5) and extreme (RCP8.5) scenarios for the periods of 2021–2040 and 2041–2060. The impact of future climate conditions was investigated on the watershed runoff and total phosphorus (TP) load, and consequently, water quality status in the dam’s reservoir. The results of comparing future conditions (2021–2060) with observed present values under moderate to extreme climate scenarios showed a 4–7% temperature increase and a 6–11% precipitation decrease. Moreover, the SWAT model showed a 9–16% decline in streamflow and a 12–18% decline in the watershed TP load for the same comparative period. Finally, CE-QUAL-W2 model results showed a 3–8% increase in the reservoir water temperature and a 10–16% increase in TP concentration. It indicates that climate change would intensify the thermal stratification and eutrophication level in the reservoir, especially during the year’s warm months. This finding specifies an alarming condition that demands serious preventive and corrective measures.</p></div>","PeriodicalId":49303,"journal":{"name":"Journal of Hydro-environment Research","volume":"40 ","pages":"Pages 28-37"},"PeriodicalIF":2.8,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49252461","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
引用次数: 4
An iterative hydraulic design methodology based on numerical modeling for piano key weirs 基于数值模拟的钢琴键堰迭代水力设计方法
IF 2.8 3区 环境科学与生态学
Journal of Hydro-environment Research Pub Date : 2022-01-01 DOI: 10.1016/j.jher.2022.01.002
Mete Koken, Ismail Aydin, Serhan Ademoglu
{"title":"An iterative hydraulic design methodology based on numerical modeling for piano key weirs","authors":"Mete Koken,&nbsp;Ismail Aydin,&nbsp;Serhan Ademoglu","doi":"10.1016/j.jher.2022.01.002","DOIUrl":"10.1016/j.jher.2022.01.002","url":null,"abstract":"<div><p>Piano Key Weir (PKW) is a special type of overflow weir which provides an improved discharge capacity with its increased crest length. Increased discharge capacity makes this weir an attractive alternative in the rehabilitation of existing spillways. After the introduction of this new weir type, many experimental and numerical studies are conducted to understand the effect of the numerous geometrical parameters on the discharge capacity. However, empirical discharge formulas suggested by different researchers are not conforming to a unique expression mostly due to dependence on the experimental conditions from which they are derived. A numerical approach is used in the present study to investigate the dependence of discharge capacity of a PKW unit on several geometric parameters. Numerical models are developed and three-dimensional velocity fields are computed using FLOW-3D® software. Discharge efficiency of a PKW over an equivalent linear sharp-crested weir is evaluated within the practical range of parameters from 145 numerical solutions for 29 different PKW models. Numerically obtained data is used to form dimensionless expressions for the weir height and length as function of discharge efficiency which are proposed to facilitate an iterative numerical solution to meet the design requirements of a given project. This approach allows cost optimization while dimensioning the PKW for the required hydraulic capacity. The design procedure based on iterative numerical solutions is described and exemplified.</p></div>","PeriodicalId":49303,"journal":{"name":"Journal of Hydro-environment Research","volume":"40 ","pages":"Pages 131-141"},"PeriodicalIF":2.8,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45908784","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
引用次数: 3
On the turbulence characteristics in developed and developing rough narrow open-channel flow 论发展中的粗窄明渠湍流特性
IF 2.8 3区 环境科学与生态学
Journal of Hydro-environment Research Pub Date : 2022-01-01 DOI: 10.1016/j.jher.2021.11.003
M. Mahananda , P.R. Hanmaiahgari , Ram Balachandar
{"title":"On the turbulence characteristics in developed and developing rough narrow open-channel flow","authors":"M. Mahananda ,&nbsp;P.R. Hanmaiahgari ,&nbsp;Ram Balachandar","doi":"10.1016/j.jher.2021.11.003","DOIUrl":"10.1016/j.jher.2021.11.003","url":null,"abstract":"<div><p>An analytical power-law for velocity distribution is developed and validated using experimental results for rough, narrow open-channel flows. In addition, an empirical power-law for the mean velocity distribution is also proposed. To this end, experiments were conducted to investigate the turbulence characteristics in developing and fully developed narrow open-channel flows over a fixed continuous rough bed. Instantaneous 3-D velocities were acquired using a Nortek VectrinoPlus down looking acoustic Doppler velocimeter at streamwise intervals of 0.5 m along the centerline of the flume. Using the experimental data, shape factors and frictional characteristics in narrow open-channel flow were analysed. In addition, this paper investigated changes in the turbulence anisotropy and the decay of turbulence along the mid-depth of the hydraulically rough flow. The new analytical power-law equation developed in this paper accurately describes the fully developed velocity profile in narrow open-channel flow with the dip phenomenon. Reynolds number and aspect ratio significantly influenced the turbulence characteristics in the upper half of the flow field. The decreasing turbulence intensities at mid-depth along the flow developing region demonstrate the attainment of isotropic turbulence as the flow development occurs in the narrow open-channel.</p></div>","PeriodicalId":49303,"journal":{"name":"Journal of Hydro-environment Research","volume":"40 ","pages":"Pages 17-27"},"PeriodicalIF":2.8,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46227724","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
引用次数: 2
DEM resolution effects on machine learning performance for flood probability mapping DEM分辨率对洪水概率映射机器学习性能的影响
IF 2.8 3区 环境科学与生态学
Journal of Hydro-environment Research Pub Date : 2022-01-01 DOI: 10.1016/j.jher.2021.10.002
Mohammadtaghi Avand , Alban Kuriqi , Majid Khazaei , Omid Ghorbanzadeh
{"title":"DEM resolution effects on machine learning performance for flood probability mapping","authors":"Mohammadtaghi Avand ,&nbsp;Alban Kuriqi ,&nbsp;Majid Khazaei ,&nbsp;Omid Ghorbanzadeh","doi":"10.1016/j.jher.2021.10.002","DOIUrl":"10.1016/j.jher.2021.10.002","url":null,"abstract":"<div><p>Floods are among the devastating natural disasters that occurred very frequently in arid regions during the last decades. Accurate assessment of the flood susceptibility mapping is crucial in sustainable development. It helps respective authorities to prevent as much as possible their irreversible consequences. The Digital Elevation Model (DEM) spatial resolution is one of the most crucial base layer factors for modeling Flood Probability Maps (FPMs). Therefore, the main objective of this study was to assess the influence of the spatial resolution of the DEMs 12.5 m (ALOS PALSAR) and 30 m (ASTER) on the accuracy of flood probability prediction using three machine learning models (MLMs), including Random Forest (RF), Artificial Neural Network (ANN), and Generalized Linear Model (GLM). This study selected 14 causative factors in the flood as independent variables, and 220 flood locations were selected as dependent variables. Dependent variables were divided into training (70%) and validation (30%) for flood susceptibility modeling. The Receiver Operating Characteristic Curve (ROC), Kappa index, accuracy, and other statistical criteria were used to evaluate the models' accuracy. The results showed that resolving the DEM alone cannot significantly affect the accuracy of flood probability prediction regardless of the applied MLM and independently of the statistical model used to assess the performance accuracy. In contrast, the factors such as altitude, precipitation, and distance from the river have a considerable impact on floods in this region. Also, the evaluation results of the models showed that the RF (AUC<sub>12.5,30m</sub> = 0.983, 0.975) model is more accurate in preparing the FPM than the ANN (AUC<sub>12.5,30m</sub> = 0.949, 0.93) and GLM (AUC<sub>12.5,30m</sub> = 0.965, 0.949) models. This study's solution-oriented findings might help water managers and decision-makers to make the most effective adaptation and mitigation measures against potential flooding.</p></div>","PeriodicalId":49303,"journal":{"name":"Journal of Hydro-environment Research","volume":"40 ","pages":"Pages 1-16"},"PeriodicalIF":2.8,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1570644321000769/pdfft?md5=13acefc3fd1e4c0759676b3882f1f2d6&pid=1-s2.0-S1570644321000769-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43538073","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 48
0
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
确定
请完成安全验证×
相关产品
×
本文献相关产品
联系我们:info@booksci.cn Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。 Copyright © 2023 布克学术 All rights reserved.
京ICP备2023020795号-1
ghs 京公网安备 11010802042870号
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术官方微信