scholarly journals Halocline Induced by Rainfall in Saline Water Ponds in the Tropics and Its Impact on Physical Water Quality

Water ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 1889
Author(s):  
Akinori Ozaki ◽  
Panitan Kaewjantawee ◽  
Thinh Nguyen Van ◽  
Masaru Matsumoto
Keyword(s):  
Water Quality ◽  
Heat Insulation ◽  
Physiological Stress ◽  
Saline Water ◽  
Vertical Mixing ◽  
Vertical Direction ◽  
Pond Water ◽  
Observation Data ◽  
The Tropics ◽  
The Impact

In saline water ponds in the tropics, a halocline may occur due to rainfall, especially in the rainy season. The critical impacts of haloclines in saline water ponds are heat insulation and the obstruction of vertical mixing. Considering the water quality in saline water ponds, the appearance of a halocline could have an impact on its variation, as the pond water quality may be impacted by both heat insulation and the obstruction of vertical mixing. Especially in saline water ponds with the purpose of aquaculture production, the appearance of a halocline may lead to dangerous risks, such as physiological stress on aquaculture products, increases in pathogenic micro-organisms, and deterioration of water quality. In the present study, the impact of the appearance of a halocline on physical water qualities was investigated by analyzing continuous on-site observation data obtained in Thailand. It was found that, after the appearance of the halocline, the heat was stored in the lower high-salinity layer, due to the heat insulation effect of the halocline. Furthermore, the halocline was also suggested to have an impact on the transportation of turbidity and to change the DO (dissolved oxygen) distribution in the vertical direction. These results are expected to provide information for assessment of the risk in saline water ponds and to contribute to a new approach for understanding deterioration problems in saline water aquaculture ponds.

Characteristics of physical water quality variation under heat storage in closed saline water aquaculture ponds in the tropics

2021 ◽  
Author(s):  
Akinori Ozaki ◽  
Panitan Kaewjantawee ◽  
Nguyen Van Thinh ◽  
Masaru Matsumoto ◽  
Masayoshi Harada ◽  
...  
Keyword(s):  
Water Quality ◽  
Heat Storage ◽  
Saline Water ◽  
Aquaculture Ponds ◽  
Water Quality Variation ◽  
The Tropics ◽  
Quality Variation

scholarly journals Hydrological Alteration Index as an Indicator of the Calibration Complexity of Water Quantity and Quality Modeling in the Context of Global Change

Water ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 115 ◽  
Author(s):  
Roxelane Cakir ◽  
Mélanie Raimonet ◽  
Sabine Sauvage ◽  
Javier Paredes-Arquiola ◽  
Youen Grusson ◽  
...  
Keyword(s):  
Climate Change ◽  
Water Quality ◽  
Water Resources ◽  
Stream Water ◽  
Swat Model ◽  
Water Yield ◽  
Observation Data ◽  
Hydrological Alteration ◽  
Water Quality And Quantity ◽  
The Impact

Modeling is a useful way to understand human and climate change impacts on the water resources of agricultural watersheds. Calibration and validation methodologies are crucial in forecasting assessments. This study explores the best calibration methodology depending on the level of hydrological alteration due to human-derived stressors. The Soil and Water Assessment Tool (SWAT) model is used to evaluate hydrology in South-West Europe in a context of intensive agriculture and water scarcity. The Index of Hydrological Alteration (IHA) is calculated using discharge observation data. A comparison of two SWAT calibration methodologies are done; a conventional calibration (CC) based on recorded in-stream water quality and quantity and an additional calibration (AC) adding crop managements practices. Even if the water quality and quantity trends are similar between CC and AC, water balance, irrigation and crop yields are different. In the context of rainfall decrease, water yield decreases in both CC and AC, while crop productions present opposite trends (+33% in CC and −31% in AC). Hydrological performance between CC and AC is correlated to IHA: When the level of IHA is under 80%, AC methodology is necessary. The combination of both calibrations appears essential to better constrain the model and to forecast the impact of climate change or anthropogenic influences on water resources.

scholarly journals An Integrated Approach for Evaluating Water Quality between 2007–2015 in Santa Cruz Island in the Galapagos Archipelago

Water ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 937 ◽  
Author(s):  
Cristina Mateus ◽  
Christian A. Guerrero ◽  
Galo Quezada ◽  
Daniel Lara ◽  
Valeria Ochoa-Herrera
Keyword(s):  
Water Quality ◽  
Population Change ◽  
Human Impacts ◽  
Saline Water ◽  
Monitoring Program ◽  
Integrated Approach ◽  
Santa Cruz Island ◽  
Santa Cruz ◽  
Background Levels ◽  
The Impact

Water quality in Galápagos has been deteriorating by increased human impacts over the past few decades. Water quality is a key environmental component and issue in need to be evaluated in the Pelican Bay Watershed, the biggest urban and economic development of Santa Cruz Island, for better management and regulation of water resources. This study assesses coastal and ground water bodies of Pelican Bay by employing a 9-year dataset obtained during a local water quality monitoring program conducted by the Galápagos National Park. Physical-chemical and microbial parameters were evaluated with respect to national and international water quality standards. A statistical integrated approach was performed to calculate environmental background levels of water quality parameters and to explore their seasonal and spatial variation. In addition, a sensitivity analysis was conducted to evaluate the impact of changes in tourism and residents in San Cruz Island in the degradation of water sources. Results highlighted are: (a) water is not suitable for drinking and domestic use at some inland sites; (b) saline water is used for irrigation in the highlands; (c) the presence of parameters of concern at coastal sites represent a risk for human and ecosystem health; (d) background levels may serve for defining site-specific limits to control water quality, and; (e) the influence of population change on water quality conditions varied at each site with a higher effect at coastal sites relatively to inland sites. This study provided valuable information of the water quality status in Santa Cruz Island and can serve as a baseline for effective water management and control of pollution.

Monitoring the impact of farm practices on water quality in the Otago and Southland deer focus farms

2006 ◽  
pp. 183-188
Author(s):  
R.W. Mcdowell ◽  
N. Mcgrouther ◽  
G. Morgan ◽  
M.S. Srinivasan ◽  
D.R. Stevens ◽  
...  
Keyword(s):  
Water Quality ◽  
Management Practices ◽  
Pond Water ◽  
Quality Parameters ◽  
Environmental Objectives ◽  
Covered Area ◽  
The Impact ◽  
Further Development ◽  
Soil And Water

Research on the soil and water quality of deer farms is minimal. However, the perception is that many deer operations may be detrimental to soil and water quality. To address this problem two deer focus farms (DFF, 1 each in Otago and Southland) were established to showcase how productivity and environmental objectives can coincide. Managements implemented by the farmers included a sedimentation pond, fencing off waterways and retiring land under a QEII covenant. A detailed soil and water quality testing regime occurred for each farm: data were collected at the Southland DFF for three tributaries (one fenced off, one partially fenced and one unfenced) which fed into a stream and through a tussock covered area retired from grazing. Water quality in the unfenced and partially fenced tributaries was poor with no water quality parameters meeting ANZECC guidelines, whereas water quality in the fenced-off and planted tributary was better. Water exiting the retired area met ANZECC guidelines. Although water quality on parts of both deer farms did not meet ANZECC guidelines, when management practices such as fencing off and the creation of a pond were used water quality improved. More importantly, an area retired from grazing and further development on the Southland DFF showed that water quality could be significantly improved and could be better than that entering the farm. Keywords: fencing-off, QEII covenant, sedimentation pond, water quality

scholarly journals Sistem Monitoring Kualitas Air Pada Budidaya Perikanan Berbasis IoT dan Manajemen Data

2021 ◽  
Vol 6 (2) ◽  
pp. 153
Author(s):  
Yudhis Thiro Kabul Yunior ◽  
Kusrini Kusrini
Keyword(s):  
Water Quality ◽  
Cloud Computing ◽  
Quality Control ◽  
Survival Rate ◽  
Internet Of Things ◽  
Web Server ◽  
Pond Water ◽  
Water Quality Control ◽  
Aquaculture Pond ◽  
The Impact

Salah satu permasalahan utama di sektor perikanan budidaya adalah sistem kontrol kualitas air yang buruk sehingga menyebabkan hama dan penyakit pada air kolam budidaya dan berdampak pada ikan yang stress dan mati. Tujuan dari pengecekan kualitas air adalah untuk mengkontrol penyakit dan bakteri pada air kolam budidaya sehingga dapat dilakukan tindakan dengan segera jika kualitas air dalam keadaan buruk. Berdasarkan permasalahan tersebut diperlukan terobosan teknologi untuk mempermudah petani ikan dalam mengkontrol kualitas air kolam budidaya. Sistem monitoring kualitas air berbasis Internet of Things (IoT) dan manajemen data sistem merupakan solusi yang tepat untuk permasalahan kontrol kalitas air pada kolam budidaya. Prinsip kerja sistem tersebut adalah dengan cara mentransfer data dari beberapa sensor kualitas air (Ph, Disolve Oxygen, Suhu, Turbidity) melalui embedded sistem pada sistem cloud computing yang kemudian data tersebut di transfer ke web server dan smartphone android sehingga petani ikan dapat memonitoring kualitas air kolam menggunakan smartphone secara realtime dan terintegrasi dengan sistem notifikasi. Jika salah satu parameter air dalam keadaaan buruk dapat dilakukan treatment air secara cepat. Dampak dari terkontrolnya kualitas air tersebut adalah meningkatkan Survival rate (SR) ikan hingga 30% sehingga dapat meningkatkan sosial ekonomi petani ikan. Kata Kunci— Internet of Things, Embeded sistem, Kualitas airAbstractOne of the main problems in the aquaculture sector is a poor water quality control system that causes pests and diseases in aquaculture pond water and impacts on stressed and dead fish. The purpose of checking water quality is to control disease and bacteria in aquaculture pond water so action can be taken immediately if the water quality is in a bad state. Based on these problems a technological breakthrough is needed to facilitate fish farmers in controlling the quality of aquaculture pond water. Internet quality monitoring system based on Internet of Things (IoT) and system data management is the right solution for the problem of water quality control in aquaculture ponds. The working principle of the system is by transferring data from several water quality sensors (Ph, Dissolve Oxygen, Temperature, Turbidity) through an embedded system on a cloud computing system which is then transferred to the web server and an android smartphone so that fish farmers can monitor water quality the pool uses a smartphone in real-time and is integrated with the notification system when one of the water parameters is in a bad state so that water treatment can be done. The impact of controlled water quality is that it can increase fish survival rate (SR) by up to 30% so that it improves the socioeconomic of fish farmers. Keywords— Internet of Things, Embeded System, Water Quality

scholarly journals Estimation and calibration of observation impact signals using the Lanczos method in NOAA/NCEP data assimilation system

2012 ◽  
Vol 19 (5) ◽  
pp. 541-557 ◽  
Author(s):  
M. Wei ◽  
M. S. F. V. De Pondeca ◽  
Z. Toth ◽  
D. Parrish
Keyword(s):  
Data Assimilation ◽  
Weather Prediction ◽  
Lanczos Method ◽  
Forecast Errors ◽  
Observation Data ◽  
Error Covariance ◽  
Observation Impact ◽  
Analysis Error ◽  
The Tropics ◽  
The Impact

Abstract. Despite the tremendous progress that has been made in data assimilation (DA) methodology, observing systems that reduce observation errors, and model improvements that reduce background errors, the analyses produced by the best available DA systems are still different from the truth. Analysis error and error covariance are important since they describe the accuracy of the analyses, and are directly related to the future forecast errors, i.e., the forecast quality. In addition, analysis error covariance is critically important in building an efficient ensemble forecast system (EFS). Estimating analysis error covariance in an ensemble-based Kalman filter DA is straightforward, but it is challenging in variational DA systems, which have been in operation at most NWP (Numerical Weather Prediction) centers. In this study, we use the Lanczos method in the NCEP (the National Centers for Environmental Prediction) Gridpoint Statistical Interpolation (GSI) DA system to look into other important aspects and properties of this method that were not exploited before. We apply this method to estimate the observation impact signals (OIS), which are directly related to the analysis error variances. It is found that the smallest eigenvalue of the transformed Hessian matrix converges to one as the number of minimization iterations increases. When more observations are assimilated, the convergence becomes slower and more eigenvectors are needed to retrieve the observation impacts. It is also found that the OIS over data-rich regions can be represented by the eigenvectors with dominant eigenvalues. Since only a limited number of eigenvectors can be computed due to computational expense, the OIS is severely underestimated, and the analysis error variance is consequently overestimated. It is found that the mean OIS values for temperature and wind components at typical model levels are increased by about 1.5 times when the number of eigenvectors is doubled. We have proposed four different calibration schemes to compensate for the missing trailing eigenvectors. Results show that the method with calibration for a small number of eigenvectors cannot pick up the observation impacts over the regions with fewer observations as well as a benchmark with a large number of eigenvectors, but proper calibrations do enhance and improve the impact signals over regions with more data. When compared with the observation locations, the method generally captures the OIS over regions with more observation data, including satellite data over the southern oceans. Over the tropics, some observation impacts may be missed due to the smaller background errors specified in the GSI, which is not related to the method. It is found that a large number of eigenvectors are needed to retrieve impact signals that resemble the banded structures from satellite observations, particularly over the tropics. Another benefit from the Lanczos method is that the dominant eigenvectors can be used in preconditioning the conjugate gradient algorithm in the GSI to speed up the convergence.

scholarly journals Reviews and syntheses: Dams, water quality and tropical reservoir stratification

2019 ◽  
Vol 16 (8) ◽  
pp. 1657-1671 ◽  
Author(s):  
Robert Scott Winton ◽  
Elisa Calamita ◽  
Bernhard Wehrli
Keyword(s):  
Water Quality ◽  
Environmental Science ◽  
Ecological Impacts ◽  
Special Focus ◽  
Tropical Reservoir ◽  
Low Latitude ◽  
Environmental Impact Assessments ◽  
Seasonal Basis ◽  
The Tropics ◽  
The Impact

Abstract. The impact of large dams is a popular topic in environmental science, but the importance of altered water quality as a driver of ecological impacts is often missing from such discussions. This is partly because information on the relationship between dams and water quality is relatively sparse and fragmentary, especially for low-latitude developing countries where dam building is now concentrated. In this paper, we review and synthesize information on the effects of damming on water quality with a special focus on low latitudes. We find that two ultimate physical processes drive most water quality changes: the trapping of sediments and nutrients, and thermal stratification in reservoirs. Since stratification emerges as an important driver and there is ambiguity in the literature regarding the stratification behavior of water bodies in the tropics, we synthesize data and literature on the 54 largest low-latitude reservoirs to assess their mixing behavior using three classification schemes. Direct observations from literature as well as classifications based on climate and/or morphometry suggest that most, if not all, low-latitude reservoirs will stratify on at least a seasonal basis. This finding suggests that low-latitude dams have the potential to discharge cooler, anoxic deep water, which can degrade downstream ecosystems by altering thermal regimes or causing hypoxic stress. Many of these reservoirs are also capable of efficient trapping of sediments and bed load, transforming or destroying downstream ecosystems, such as floodplains and deltas. Water quality impacts imposed by stratification and sediment trapping can be mitigated through a variety of approaches, but implementation often meets physical or financial constraints. The impending construction of thousands of planned low-latitude dams will alter water quality throughout tropical and subtropical rivers. These changes and associated environmental impacts need to be better understood by better baseline data and more sophisticated predictors of reservoir stratification behavior. Improved environmental impact assessments and dam designs have the potential to mitigate both existing and future potential impacts.

scholarly journals Predicting Lake Eutrophication Responses to Multiple Scenarios of Lake Restoration: A Three-Dimensional Modeling Approach

Water ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 994 ◽  
Author(s):  
Yanping Wang ◽  
Weiping Hu ◽  
Zhaoliang Peng ◽  
Ye Zeng ◽  
Karsten Rinke
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Three Dimensional ◽  
Water Transfer ◽  
Nutrient Concentrations ◽  
Observation Data ◽  
Nutrient Reduction ◽  
Effective Measure ◽  
The Impact ◽  
Restoration Measures

To improve the water quality and alleviate the eutrophication of Lake Yangchenghu, the third largest freshwater body within the Lake Taihu basin in China and an important source of drinking water, nutrient reduction strategies should be urgently addressed by decision makers, since virtually no improvement of water quality has taken place since the mid-1990s. Due to the lack of sufficient observation data and simulation results, a vertically compressed three-dimensional numerical model, the EcoTaihu model, was used to study the impact of three restoration measures on the water quality—namely, total nitrogen (TN), total phosphorus (TP) and biomass of phytoplankton (BP)—of Lake Yangchenghu: (i) total nutrient reduction, (ii) intensification of flushing by water transfer, and (iii) spatial adjustment of inflow channels. In particular, the spatial effects of the three restoration measures on the water quality were investigated. The results showed that the EcoTaihu model is applicable to other shallow lakes in China. The water quality responses to the different restoration scenarios showed significant spatio-temporal differences. The reduction of nutrient loads from inflows appeared to be the most effective measure for controlling the eutrophication and algal blooms in Lake Yangchenghu. The effectiveness of water transfer on the improvement of water quality for TN and TP was more influenced by the differences of nutrient concentrations between the transferred water and lake water, rather than flow rate, since no proportionate increase of improvement was observable in the case of larger transferred rates (60 m3 s−1). The spatial narrowing of inflowing rivers in the southwestern lake could preferentially improve the water quality in the southern bay of the western lake, but would also result in a deterioration trend of water quality in the total lake and drinking water abstraction areas.

Estimation of Lake Urmia Evaporation from the Combined Ground-based and Satellite Imagery Data

2020 ◽  
Author(s):  
Mohammad Abdoli ◽  
Mohammad Danesh-Yazdi ◽  
Alireza Arabzadeh ◽  
Mostafa Javadian ◽  
Massoud Tajrishy
Keyword(s):  
Saline Water ◽  
Bowen Ratio ◽  
Accurate Estimation ◽  
Hypersaline Lake ◽  
Observation Data ◽  
Lake Urmia ◽  
Water Balance Components ◽  
Annual Average ◽  
Main Component ◽  
The Impact

<p>Lake Urmia (LU) has been the second-largest hypersaline lake in the world located in the northwest of Iran that encountered a drastic drawdown in the water level over the past two decades. Accurate estimation of the water balance components, particularly evaporative loss from the water surface as the main component of the LU water budget, is important for the lake water management and restoration programs. In this study, long-term evaporation from the LU surface was estimated between 2000 and 2017 using the Bowen Ratio Energy Balance (BREB), Priestley-Taylor, DeBruin-Keijman, Penman, and Stephans-Stewart methods that leverage meteorological observations and Terra Moderate Resolution Imaging Spectroradiometer (MODIS) satellite earth observation data. The impact of water salinity on evaporation was also considered through dynamic water activity coefficient as well as water density. Given observations from the saline water pan evaporation located in the Lake vicinity, the Debruin-Keijman method yielded the most accurate estimation with the correlation coefficient of 0.93, the root means square error (RMSE) of 121 mm in annual scale. The minimum and maximum annual evaporation were estimated as 783 mm and 1216 mm in 2011 and 2000, respectively, with the annual average evaporation for the entire period, were 1077 mm. By extracting monthly lake surface area from image classification techniques, monthly and annual volumetric evaporation were estimated, indicating that the annual average of the lake volumetric evaporation approximates to 3.6 BCM, which exceeds LU annual environmental requirement water of 3.1 BCM.</p>

Emotions and health: The impact of emotions, emotions regulation, music, and acculturation on health

2008 ◽  
Vol 16 (3) ◽  
pp. 112-115 ◽  
Author(s):  
Stephan Bongard ◽  
Volker Hodapp ◽  
Sonja Rohrmann
Keyword(s):  
Stress Responses ◽  
Physiological Stress ◽  
Anger Expression ◽  
Domain Specific ◽  
Cardiovascular Stress ◽  
Expression Behavior ◽  
Cardio Vascular ◽  
And Coping ◽  
Relationship Of ◽  
The Impact

Abstract. Our unit investigates the relationship of emotional processes (experience, expression, and coping), their physiological correlates and possible health outcomes. We study domain specific anger expression behavior and associated cardio-vascular loads and found e.g. that particularly an open anger expression at work is associated with greater blood pressure. Furthermore, we demonstrated that women may be predisposed for the development of certain mental disorders because of their higher disgust sensitivity. We also pointed out that the suppression of negative emotions leads to increased physiological stress responses which results in a higher risk for cardiovascular diseases. We could show that relaxation as well as music activity like singing in a choir causes increases in the local immune parameter immunoglobuline A. Finally, we are investigating connections between migrants’ strategy of acculturation and health and found e.g. elevated cardiovascular stress responses in migrants when they where highly adapted to the German culture.

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