water quality variable
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Hydrology ◽  
2021 ◽  
Vol 8 (2) ◽  
pp. 62
Author(s):  
Israel A. Olaoye ◽  
Remegio B. Confesor ◽  
Joseph D. Ortiz

The separate and synergistic effects of land use and climate change on water quality variables in Old Woman Creek (OWC) watershed were evaluated using a hydrological model set up in Soil and Water Assessment Tool (SWAT) for the OWC watershed. Model calibration was done using a multi-objective evolutionary algorithm and pareto optimization. The Parameter-Elevation Regressions on Independent Slopes Model (PRISM) climate data and the 20 different Global Circulation Models (GCMs) developed by the Coupled Model Intercomparison Project Phase five (CMIP5) were used. Validation was done using the streamflow data from USGS gaging station and water quality data from the water quality lab, Heidelberg University. The simulation was divided into two land use scenarios: Scenario 1 for constant land use and Scenario 2 where land use was varied. Both land use simulations were run in four time periods to account for climate change: historical (1985–2014), current to near future (2018–2045), mid-century (2046–2075), and late-century (2076–2100) climate windows. For the historical period, the average of all the simulations made from the 20 different CMIP5 GCMs shows good agreement with the PRISM results for flow and the water quality variables of interest with smaller inter-model variability compared to PRISM results. For the other three climate windows, the results of Scenario 1 show an increase in flow and eight water quality variables (sediment (total suspended sediment), organic nitrogen, organic phosphorus (particulate p), mineral phosphorus (soluble reactive p), chlorophyll a, carbonaceous biochemical oxygen demand (CBOD), dissolved oxygen, total nitrogen) across the climate windows but a slight decrease in one water quality variable, mineral phosphorus in the mid-century. The results of Scenario 2 show a greater increase in flow, and the eight water quality variables across the climate windows show a relatively larger decrease in one water quality variable (mineral phosphorus). The projected land use change has little impact compared to the projected climate change on OWC watershed in the 21st century.


Climate ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 50
Author(s):  
Israel A. Olaoye ◽  
Remegio B. Confesor ◽  
Joseph D. Ortiz

The effect of the projected 21st century climate change on water quality in Old Woman Creek (OWC) watershed was evaluated using the Soil and Water Assessment Tool (SWAT) and the precipitation and temperature projections from three best Global Climate Circulation Model (GCM)l ensemble downloaded from the Coupled Model Intercomparison Project Phase 5 (CMIP5). These three best GCMs (GFDL-ESM2M, MPI-ESM-MR, EC-EARTH) were identified as those closest to the multivariate ensemble average of twenty different GCM-driven SWAT simulations. Seasonal analysis was undertaken in historical (1985–2014), current to near future (2018–2045), mid-century (2046–2075), and late-century (2076–2100) climate windows. The hydrological model calibration was carried out using a multi-objective evolutionary algorithm and pareto optimization. Simulations were made for stream flow and nine water quality variables (sediment, organic nitrogen, organic phosphorus, mineral phosphorus, chlorophyll a, carbonaceous biochemical oxygen demand, dissolved oxygen, total nitrogen, and total phosphorus) of interest. The average of twenty different CMIP5-driven SWAT simulation results showed good correlation for all the 10 variables with the PRISM-driven SWAT simulation results in the historical climate window (1985–2014). For the historical period, the result shows an over-estimation of flow, sediment, and organic nitrogen from January to March in simulations with CMIP5 inputs, relative to simulations with PRISM input. For the other climate windows, the simulation results show a progressive increase in stream flow with peak flow month shifting from April to March. The expected seasonal changes in each water quality variable have implications for the OWC estuary and Lake Erie water quality.


2020 ◽  
Vol 11 (1) ◽  
pp. 44-50
Author(s):  
Heri Ariadi ◽  
Abdul Wafi ◽  
Supriatna

FCR or feed conversion ratio is one of the strategic indicators on pond production which is very important for determining the costs incurred during the shrimp culture period. The purpose of this study was to examine the relationship between water physico-chemical parameters and the conversion rate of shrimp feed in intensive shrimp ponds (Litopenaeus vannamei). The research method used in this study is the ex-pose facto design during shrimp culture cycle with uniformity of treatment during the cultivation process, then the research collective data obtained periodically is analyzed by multiple linear regression. The results of this study indicate that all pond water quality variables based on quality standards are still in accordance with the standards intended for aquaculture. While based on regression analysis and t-test, the temperature variable is the only parameter that has a direct influence on the FCR efficiency by shrimp. As well as temperature, salinity, and alkalinity variables are parameters that have a close level of relationship to the FCR value in the ponds of 84.1%, 79.1%, and 69.9%. The conclusion of this study is that in intensive ponds the parameters of temperature, salinity, and alkalinity are water quality parameters that have a close relationship with the efficiency of FCR values ​​in ponds, with temperature parameters being the water quality variable which has a direct influence on the effectiveness of the feed conversion ratio by shrimp.


2019 ◽  
Vol 7 (5) ◽  
pp. 657
Author(s):  
Zulhilmi Zulhilmi ◽  
Idawati Idawati

<p>Clean water is one of the important needs in human life and a natural resource that has a very vital function. A preliminary study conducted in Peudada Subdistrict by visiting 20 community houses in several villages found that the community was increasingly aware of the importance of clean water, which led to increased demand for clean water. The purpose of the study was to analyze the factors that influence the level of implementation of management of clean water consumption in households in Peudada Subdistrict, Bireuen District in 2019. This type of research is a quantitative study conducted by analytic survey with cross sectional approach. The population is the number of all adolescents as many as 4,892 families, using the sample solvin formula in this study 98 families. The results showed that there was a relationship between family income and water consumption, with a probability value (0.029) &lt;sig_α = 0.05, there was a relationship between the number of family members with water consumption, with a probability value (0.019) &lt;sig_α = 0.05, there was a relationship family members with water consumption, with a probability value (0,000) &lt;sig_α = 0.05, there is a relationship between other clean water sources and water consumption, with a probability value (0.019) &lt;sig_α = 0.05 and the dominant clean water quality variable influences management clean water consumption because it has an EXP value (B) with an overall value of percentage = 64.3%.<br />Keyword : Management of Clean Water Consumption, Households</p><p>ABSTRAK</p><p>Air bersih merupakan salah satu kebutuhan penting dalam kehidupan manusia dan menjadi sumber daya alam yang memiliki fungsi sangat vital. Studi pendahuluan yang dilakukan di Kecamatan Peudada dengan mendatangi 20 rumah masyarakat di beberapa desa menemukan hasil bahwa masyarakat semakin sadar dengan pentingnya air bersih sehingga menyebabkan meningkatnya permintaan ait bersih. Tujuan penelitian untuk menganalisis faktor yang memengaruhi tingkat penerapan pengelolaan konsumsi air bersih pada rumah tangga di Kecamatan Peudada Kabupaten Bireuen tahun 2019. Jenis penelitian ini merupakan penelitian kuantitatif yang dilakukan secara survey analitik dengan pendekatan crosssectional. Populasi adalah jumlah seluruh remaja sebanyak 4.892 KK, dengan menggunakan rumus solvin sampel dalam penelitian ini 98 KK. Hasil penelitian menunjukkan bahwa ada hubungan pendapatan keluarga dengan konsumsi air, dengan nilai probabilitasnya (0,029) &lt;sig_α = 0,05, ada hubungan jumlah anggota keluarga dengan konsumsi air, dengan nilai probabilitasnya (0,019) &lt;sig_α = 0,05, ada hubungan jumlah anggota keluarga dengan konsumsi air, dengan nilai probabilitasnya (0,000)&lt;sig_α = 0,05, ada hubungan sumber air bersih lain dengan konsumsi air, dengan nilai probabilitasnya (0,019)&lt;sig_α = 0,05 dan variabel kualitas air bersih dominan memengaruhi penerapan pengelolaan konsumsi air bersih karena memiliki nilai EXP (B) dengan nilai Overall percentage= 64,3%<br />Kata Kunci : Pengelolaan Konsumsi Air Bersih, Rumah Tangga</p>


Author(s):  
Etornyo Agbeko ◽  
Nelson W. Agbo ◽  
Thomas K. Agyemang ◽  
Daniel Adjei-Boateng

Understanding aquatic ecosystem dynamics is fundamental to sustainable development of aquaculture. This study explores the water quality characteristics over temporal and spatial scale in Tono and Vea Reservoirs in the Upper East Region of Ghana for aquaculture development. Water samples and in-situ measurements were taken for fifteen months, from February 2015 to March 2016. Monthly water quality monitoring were based on stratified sampling from upstream, midstream and downstream zones of these reservoirs. Standard analytical methods for examination of water were employed during sampling and laboratory analysis of reservoir water quality. Phytoplankton analysis was done using light microscopy to obtain phylum abundance. Multivariate statistical methods were used to investigate water quality dataset obtained. Cluster analysis grouped fifteen months of water quality changes into three seasonality regimes (periods) based on temporal variation. Principal component analysis (PCA) reduced eighteen water quality variables into five and three factors with total variance of 88.26 % and 79.30% for Tono and Vea reservoirs, respectively. With pH > 7 and alkalinity > 20 but < 100 mg L-1 CaCO3, both reservoirs have alkaline water. Dissolved oxygen was > 5 mg L-1. Three phyla of phytoplankton were identified with dominant (in abundance) phylum as Chlorophyta (72%) occurring in Tono reservoir. To understand the spatial relationship using correspondence analysis (CA), the first axis of CA explained 84.2% and 64.3% of total variation in relative abundance of phytoplankton phyla for Tono and Vea reservoirs, respectively. Thus, Cyanophyta showed strong positive association with conductivity, total hardness, nitrate, sulphate, turbidity, water depth and dissolved oxygen which were responsive to the midstream and upstream zones of Tono reservoir. Whiles in Vea reservoir, Chlorophyta under same water quality variable showed responsiveness to the midstream and downstream zones. Reservoir water quality studied were within acceptable limits for fish culture but changes could be linked to anthropogenic activities on reservoir catchment area and seasonality regime. Results from this provide a baseline to enable information to enable assessment of aquaculture impact in Tono and Vea reservoirs. The use of multivariate analysis could be a reliable statistical method for assessing water quality on a spatio-temporal scale.


2015 ◽  
Vol 74 (1) ◽  
Author(s):  
Mohd Fadhil Kasim ◽  
Hafizan Juahir ◽  
Ismail Tawnie ◽  
Azman Azid ◽  
Ahmad Shakir Mohd Saudi ◽  
...  

In this research, determination of water quality status was carried out by using non-parametric Mann-Kendall analysis for the Linggi River Basin and for classification of the river, HACA and PCA has been used to classify the river to obtain the clearest picture of the water quality status. The dataset includes 6 parameters for 6 monitoring stations (1997 to 2012). Mann-Kendall trend analysis shows trend analysis indicate that significant improvement trend for all parameters studied except for BOD (WQ1 (P<0.1) and WQ6 (P<0.05)) and SS (WQ4 to WQ6 (P<0.05)) trend were shows the unhealthy significant trend. This indicates that even though the WQI getting good in trend, a few parameters such as BOD and SS need to be watched and enforcement by the local authority need to be done to make sure the WQI continuously getting better in the future. HACA grouped the six monitoring stations into three different clusters based on their similarities namely less pollution site (LPS), medium pollution site (MPS) and high pollution site (HPS). HACA indicate one station (WQ1) into group LPS, two stations into MPS (WQ2 and WQ3) and three stations into HPS (WQ4, WQ5 and WQ6) respectively. PCA was used to investigate the origin of each water quality variable based on the clustered region. Three principal components (PCs) were obtained with 75.3% total variation for HPS, 73.4% for MPS and 68.1% for LPS. The major pollution source for HPS are of anthropogenic source (municipal waste, domestic wastes) while for MPS the major source of pollution was from non point source pollution such as animal husbandry in livestock farm. For the LPS, major source comes from the sea tide effect (natural effect). The identification and classification of different region by this study will help the local authorities make better and more informed decisions about the improvement water quality program for the future.


2012 ◽  
Vol 16 (7) ◽  
pp. 2253-2266 ◽  
Author(s):  
B. Khalil ◽  
J. Adamowski

Abstract. In many situations the extension of hydrological or water quality time series at short-gauged stations is required. Ordinary least squares regression (OLS) of any hydrological or water quality variable is a traditional and commonly used record extension technique. However, OLS tends to underestimate the variance in the extended records, which leads to underestimation of high percentiles and overestimation of low percentiles, given that the data are normally distributed. The development of the line of organic correlation (LOC) technique is aimed at correcting this bias. On the other hand, the Kendall-Theil robust line (KTRL) method has been proposed as an analogue of OLS with the advantage of being robust in the presence of outliers. Given that water quality data are characterised by the presence of outliers, positive skewness and non-normal distribution of data, a robust record extension technique is more appropriate. In this paper, four record-extension techniques are described, and their properties are explored. These techniques are OLS, LOC, KTRL and a new technique proposed in this paper, the robust line of organic correlation technique (RLOC). RLOC includes the advantage of the LOC in reducing the bias in estimating the variance, but at the same time it is also robust in the presence of outliers. A Monte Carlo study and empirical experiment were conducted to examine the four techniques for the accuracy and precision of the estimate of statistical moments and over the full range of percentiles. Results of the Monte Carlo study showed that the OLS and KTRL techniques have serious deficiencies as record-extension techniques, while the LOC and RLOC techniques are nearly similar. However, RLOC outperforms OLS, KTRL and LOC when using real water quality records.


2012 ◽  
Vol 9 (4) ◽  
pp. 4667-4702 ◽  
Author(s):  
B. Khalil ◽  
J. Adamowski

Abstract. In many situations the extension of hydrological or water quality time series at short-gauged stations is required. Ordinary least squares regression (OLS) of any hydrological or water quality variable is a traditional and commonly used record extension technique. However, OLS tends to underestimate the variance in the extended records, which leads to underestimation of high percentiles and overestimation of low percentiles, given that the data is normally distributed. The development of the line of organic correlation (LOC) technique is aimed at correcting this bias. On the other hand, the Kendall-Theil robust line (KTRL) method has been proposed as an analogue of OLS with the advantage of being robust in the presence of outliers. Given that water quality data are characterised by the presence of outliers, positive skewness and non-normal distribution of data, a robust record extension technique is more appropriate. In this paper, four record-extension techniques are described, and their properties are explored. These techniques are OLS, LOC, KTRL and a new technique proposed in this paper, the robust line of organic correlation technique (RLOC). RLOC includes the advantage of the LOC in reducing the bias in estimating the variance, but at the same time it is also robust to the presence of outliers. A Monte Carlo study and empirical experiment were conducted to examine the four techniques for the accuracy and precision of the estimate of statistical moments and over the full range of percentiles. Results of the Monte Carlo study showed that the OLS and KTRL techniques have serious deficiencies as record-extension techniques, while the LOC and RLOC techniques are nearly similar. However, RLOC outperforms OLS, KTRL and LOC when using real water quality records.


2012 ◽  
Vol 2012 ◽  
pp. 1-10
Author(s):  
Arijit Pal ◽  
Devashish Chandra Sinha ◽  
Neelkamal Rastogi

The abundance patterns of two insects,Gerris spinolaeandBrachydeutera longipes, were found to be affected by abiotic aquatic factors including free carbon dioxide, dissolved oxygen, BOD, and phosphate concentrations prevailing in four tropical freshwater ponds, three of which being anthropogenically stressed. Regression analysis between each individual-independent water quality variable and insect abundance demonstrated a significant positive correlation in each case betweenB. longipesabundance and BOD, phosphate, free CO2, and algae dry weight, while a significant negative correlation of each of these variables was found withGerris spinolaeabundance. Moreover, a significant negative correlation ofB. longipesabundance was calculated with dissolved oxygen concentration, whileG. spinolaeabundance exhibited a positive correlation with the same. Thus,G. spinolaeappears to be a pollution sensitive, effective bioindicator for healthy unpolluted ponds, whileB. longipeshas potential as a pollution-resistant insect species indicative of pollution occurrence.


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