The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Ana Allende - One of the best experts on this subject based on the ideXlab platform.
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ultrasound treatments improve the microbiological quality of Water Reservoirs used for the irrigation of fresh produce
Food Research International, 2015Co-Authors: Maria V Villanueva, Maria C Luna, Ana AllendeAbstract:Abstract Irrigation Water has been highlighted as a source of microbial contamination in produce. Water treatment has been recommended as an intervention strategy to reduce microbial risks associated to irrigation Water. Commercial Water treatments mostly depend on chemical agents; although growers search for greener alternatives to chemical biocides. Ultrasounds (US) have been proposed as an environmentally friendly technology for irrigation Water. In the present study, the suitability of two US treatments (20 kHz: US20 and 40 kHz: US40 at a specific energy (Es) of 745 J/L) and one chlorine treatment (1–2 ppm free chlorine) was evaluated and compared to the untreated control. Five Water Reservoirs belonging to five commercial intensive farms were selected as representative of irrigation practices generally used in south of Europe. All tested Water treatments were able to reduce microbial loads, including Escherichia coli (0.5–0.6 log units), to values that were accepted in most of the recommended guidelines of good agricultural practices (≤ 2 log units). The obtained reductions were lower than those previously reported for these Water treatment technologies in lab-scale tests. High microbial reductions are commonly obtained in laboratory studies, yielding impressive results. However, when the same treatments are applied under real commercial conditions, microbial reductions are usually less impressive. All Water treatments were able to reduce COD of irrigation Water when compared to the untreated control. COD reductions obtained using chlorine (≥ 430 mg/L) and US 20 (~ 100 mg/L) were higher than those observed using US 40 (
Ge Liu - One of the best experts on this subject based on the ideXlab platform.
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characterization of cdom in Reservoirs and its linkage to trophic status assessment across china using spectroscopic analysis
Journal of Hydrology, 2019Co-Authors: Yingxin Shang, Kaishan Song, Pierre A Jacinthe, Zhidan Wen, Lili Lyu, Chong Fang, Ge LiuAbstract:Abstract Chromophoric dissolved organic matter (CDOM) represents the optically active component of the DOM pool, and originates from both allochthonous and autochthonous sources. The fluorescent characteristics of dissolved organic matter (FDOM) has been widely used to trace CDOM sources and infer its composition. However, little is known about the optical and fluorescent properties of CDOM in drinking Water Reservoirs, and the variability of CDOM properties along trophic gradients in these aquatic systems. A total of 536 Water samples were collected between 2015 and 2017 from 131 Reservoirs across China to characterize CDOM and FDOM properties using both light absorption and fluorescence spectroscopies, and examine relationships with Water-quality condition as expressed by the modified trophic state index (TSIM) of the Reservoirs (range: 12 70. This method highlights the importance of CDOM fluorescence for aquatic DOM input and strengthens the linkage between the trophic status index and CDOM characteristics, it also contributes to establish a new rapid assessing model with quick experimental measurements to monitor the trophic status of Water Reservoirs.
Maria V Villanueva - One of the best experts on this subject based on the ideXlab platform.
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ultrasound treatments improve the microbiological quality of Water Reservoirs used for the irrigation of fresh produce
Food Research International, 2015Co-Authors: Maria V Villanueva, Maria C Luna, Ana AllendeAbstract:Abstract Irrigation Water has been highlighted as a source of microbial contamination in produce. Water treatment has been recommended as an intervention strategy to reduce microbial risks associated to irrigation Water. Commercial Water treatments mostly depend on chemical agents; although growers search for greener alternatives to chemical biocides. Ultrasounds (US) have been proposed as an environmentally friendly technology for irrigation Water. In the present study, the suitability of two US treatments (20 kHz: US20 and 40 kHz: US40 at a specific energy (Es) of 745 J/L) and one chlorine treatment (1–2 ppm free chlorine) was evaluated and compared to the untreated control. Five Water Reservoirs belonging to five commercial intensive farms were selected as representative of irrigation practices generally used in south of Europe. All tested Water treatments were able to reduce microbial loads, including Escherichia coli (0.5–0.6 log units), to values that were accepted in most of the recommended guidelines of good agricultural practices (≤ 2 log units). The obtained reductions were lower than those previously reported for these Water treatment technologies in lab-scale tests. High microbial reductions are commonly obtained in laboratory studies, yielding impressive results. However, when the same treatments are applied under real commercial conditions, microbial reductions are usually less impressive. All Water treatments were able to reduce COD of irrigation Water when compared to the untreated control. COD reductions obtained using chlorine (≥ 430 mg/L) and US 20 (~ 100 mg/L) were higher than those observed using US 40 (
Jeffrey J Mcdonnell - One of the best experts on this subject based on the ideXlab platform.
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ecohydrologic separation of Water between trees and streams in a mediterranean climate
Nature Geoscience, 2010Co-Authors: Renee J Brooks, H R Barnard, Rob Coulombe, Jeffrey J McdonnellAbstract:Water movement in upland humid Watersheds from the soil surface to the stream is often described using the concept of translatory flow, which assumes that Water at any soil depth is well mixed. A study of Water isotopes in an Oregon Watershed instead suggests that trees and streams tap into separate Water Reservoirs.
Vijay P Singh - One of the best experts on this subject based on the ideXlab platform.
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fractal based evaluation of the effect of Water Reservoirs on hydrological processes the dams in the yangtze river as a case study
Stochastic Environmental Research and Risk Assessment, 2014Co-Authors: Yu Zhou, Qiang Zhang, Vijay P SinghAbstract:Water Reservoirs exercise a considerable influence on hydrological processes and their influence can be treated as one of the influences of human activities on the hydrological cycle at the regional and even global scale. Long daily streamflow series from two gauging stations, Cuntan and Yichang, are analyzed to quantify the effect of the Gezhouba- and the Three Gorges Dams on the Yangtze River flow variations. The Cuntan- and Yichang stations are located up- and downstreams of these two dams, respectively. The quantification entails the employment of conventional multifractal analysis (MFA) and MF-detrended fluctuation analysis (MF-DFA). The streamflow series are divided into six segments based on the time when the Gezhouba- and Three Gorges Dams were constructed. Thus, the effect of these two dams can be compared through MF properties of streamflow before and after the construction of Water Reservoirs. The effect of the Gezhouba Dam on streamflow downstream may not be reflected by conventional MFA but can be seen from the results of MF-DFA. It should be due to the fact that MF-DFA is on the basis of fluctuations around the dominant trend, reflecting more local information; while the box-counting algorithms investigate the streamflow from the whole view. Particularly, for the inter-station comparison of results obtained by MF-DFA-based analysis, the strongest impact on the streamflow downstream is indicated by the most significant difference in generalized fractal dimension spectrum appearing during the construction of Gezhouba Dam. In addition, after the construction of Gezhouba Dam, the minimal MF dimension at Yichang station start to be less than that at Cuntan station, suggesting that the streamflow becomes less fluctuated, which should be attributed to the filter effect of Water reservoir. This study presents a feasible way to evaluate, wholly and locally, the impact of Water Reservoirs on streamflow in other river basins in the world.
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trend periodicity and abrupt change in streamflow of the east river the pearl river basin
Hydrological Processes, 2014Co-Authors: Qiang Zhang, Vijay P SinghAbstract:The East River in the Pearl River basin, China, plays a vital role in the Water supply for mega-cities within and in the vicinity of the Pearl River Delta. Knowledge of statistical variability of streamflow is therefore important for Water resources management in the basin. This study analyzed streamflow from four hydrological stations on the East River for a period of 1951–2009, using ensemble empirical mode decomposition (EEMD), continuous wavelet transform (CWT) technique, scanning t and F tests. Results indicated increasing/decreasing streamflow in the East River basin before/after the 1980s. After the early 1970s, the high/low flow components were decreasing/increasing. CWT-based analysis demonstrates a significant impact of Water Reservoirs on the periodicity of streamflow. Scanning t and F test indicates that significantly abrupt changes in streamflow are largely influenced by both Water Reservoirs construction and precipitation changes. Thus, changes of streamflow, which are reflected by variations of trend, periodicity and abrupt change, are due to both Water reservoir construction and precipitation changes. Further, the changes of volume of streamflow in the East River are in good agreement with precipitation changes. Copyright © 2012 John Wiley & Sons, Ltd.
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space time changes in hydrological processes in response to human activities and climatic change in the south china
Stochastic Environmental Research and Risk Assessment, 2012Co-Authors: Xinjun Tu, Vijay P Singh, Qiang Zhang, Xiaohong Chen, Shaobo WangAbstract:Due to the influence of climate change and human activities, more and more regions around the world are nowadays facing serious Water shortages. This is particularly so with the Guangdong province, an economically prosperous region in China. This study aims at understanding the abrupt behavior of hydrological processes by analyzing monthly precipitation series from 257 rain gauging stations and monthly streamflow series from 25 hydrological stations using the likelihood ratio statistic and schwarz information criterion (SIC). The underlying causes of the changing properties of hydrological processes are investigated by analyzing precipitation changes and information of Water Reservoirs. It is found that (1) streamflow series in dry season seems to exhibit abrupt changes when compared to that in the flood season; (2) abrupt changes in the values of mean and variance of hydrological variables in the dry season are more common than those in the streamflow series in the flood season, which implies that streamflow in the dry season is more sensitive to human activities and climate change than that in the flood season; (3) no change points are identified in the annual precipitation and precipitation series in the flood season. Annual streamflow and streamflow in the flood season exhibit no abrupt changes, showing the influence of precipitation on streamflow changes in the flood season. However, streamflow changes in the dry season seem to be heavily influenced by hydrological regulations of Water Reservoirs. The results of this study are of practical importance for regional Water resource management in the Guangdong province.
