A Comparative Accuracy of Regularized and Tension Spline Methods to Estimate and Model the Surface Water pH of Pulau Tuba, Langkawi, Kedah

This research is conducted to assess the accuracy of spline interpolation methods to predict and model the surface water pH of Pulau Tuba, Langkawi, Kedah, Malaysia. In-situ sampling activities using pH-meter and Geographic Positioning Systems (GPS) were carried out during high tides and at noon in November 2018. The development of spatial models was constructed using Regularized and Tension spline methods. Then, validation of models was carried out to compare the observed and predicted values of pH using correlation analysis, regression analysis, and error analysis. The accuracy of the developed map was calculated using the overall accuracy equation. This research found that the regularized spline method had more accuracy in estimating surface water pH variability than the tension spline method. Pearson correlation coefficient (r), Coefficient of determination (R2), Mean Absolute Error (MAE) and Root Mean Square Error (RMSE) were reported at 0.896, 0.803, 0.0265 and 0.0344 for the regularized spline method,respectively. The developed spatial model was then transformed into a map by adding map elements such as legend, title, north arrow, and scales for effective visualization. The developed map has an accuracy of 87.50%. The surface water pH was found at the range of 7-8. Low reading of pH is expected due to the addition of rainwater to the coastal water of Pulau Tuba, Langkawi, Kedah. The research outcomes would benefit government and non-government agencies to monitor the coastal and ocean acidification and the development of strategic policies and rules to reduce the impact of anthropogenic activities and climate changes for this area.

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Controls on pH in surface waters of northwestern European shelf seas

Biogeosciences Discussions ◽

10.5194/bgd-11-943-2014 ◽

2014 ◽

Vol 11 (1) ◽

pp. 943-974 ◽

Cited By ~ 4

Author(s):

V. M. C. Rérolle ◽

M. Ribas-Ribas ◽

V. Kitidis ◽

I. Brown ◽

D. C. E. Bakker ◽

...

Keyword(s):

Biological Activity ◽

Surface Water ◽

Irish Sea ◽

Carbonate Chemistry ◽

Ph Distribution ◽

European Shelf ◽

Shelf Seas ◽

Water Ph ◽

The Impact ◽

Chemistry Dynamics

Abstract. We present here a high resolution surface water pH dataset obtained in the Northwest European shelf seas in summer 2011. This is the first time that pH has been measured at such a high spatial resolution (10 measurements h–1) in this region. The aim of our paper is to investigate the carbonate chemistry dynamics of the surface water using pH and ancillary data. The main processes controlling the pH distribution along the ship's transect, and their relative importance, were determined using a statistical approach. The study highlights the impact of biological activity, temperature and riverine inputs on the carbonate chemistry dynamics of the shelf seas surface water. For this summer cruise, the biological activity formed the main control of the pH distribution along the cruise transect. Variations in chlorophyll and nutrients explained 29% of the pH variance along the full transect and as much as 68% in the northern part of the transect. In contrast, the temperature distribution explained ca. 50% of the pH variation in the Skagerrak region. Riverine inputs were evidenced by high dissolved organic carbon (DOC) levels in the Strait of Moyle (northern Irish Sea) and the southern North Sea with consequent remineralisation processes and a reduction in pH. The DOC distribution described 15% of the pH variance along the full transect. This study highlights the high spatial variability of the surface water pH in shelf seawaters where a range of processes simultaneously impacts the carbonate chemistry.

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Assessment of Anthropogenic Impact of Surface Water Quality, South Africa

Aquatic Science and Technology ◽

10.5296/ast.v6i2.12837 ◽

2018 ◽

Vol 6 (2) ◽

pp. 12

Author(s):

Dipitseng Manamela ◽

Omotayo Awofolu

Keyword(s):

South Africa ◽

Water Quality ◽

Surface Water ◽

Anthropogenic Activities ◽

Treatment Plant ◽

Surface Water Quality ◽

Total Coliform ◽

Mean Values ◽

Physico Chemical ◽

The Impact

This article investigates the impact of anthropogenic activities on an important surface water from physico-chemical, chemical and microbial perspectives. The surface water, referred to as Blesbokspruit is in the West Rand District of South Africa. Potential impactors include wastewater treatment plant, mines, farmlands and informal settlements. Water samples were collected from nine purposively selected sampling points and analysed in 2014. The mean values of analysed variables across sampling sites and periods ranged from pH: 7.4-8.4; EC: 93.0 - 146.6 mS/m; TSS: 11.3 – 39.0 mg/L; TDS: 590.3 - 1020.3 mg/L; COD: 15.6- 34.8 mg/L. Those for anions varied from NO3-: 0.2- 2.1 (mg/L) N; PO43- : 0.4-0.9 mg/L and SO42-: 118.6 - 379.5 mg/L. The metallic variables ranged from As: 0.01-0.06 mg/L; Cd: 0.02-0.06 mg/L; Fe: 0.04-0.73 mg/L; Cu: 0.02 – 0.05 mg/L and Zn: 0.05 – 0.15 mg/L. The Faecal coliform varied from 15.9-16878.5 cfu/100 ml; Total coliform: 92.9-430294 cfu/100 ml and HPC from 4322.5-39776 cfu/1ml. Detection of toxic metals and pathogenic organisms above target safety limits indicate unsuitability of the water for domestic use with impact on the health of aquatic ecosystem. The study generally revealed the impact of anthropogenic activities on the surface water quality.

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The Impacts of Climate-Induced Agricultural Drought on Four Cereal Crops: A Case Study in Bako Tibe District, Oromia National Regional State, Ethiopia

Caraka Tani Journal of Sustainable Agriculture ◽

10.20961/carakatani.v35i1.35749 ◽

2020 ◽

Vol 35 (1) ◽

pp. 135

Author(s):

Terefa Adunya ◽

Fedhasa Chalchisa Benti

Keyword(s):

Crop Yields ◽

Pearson Correlation ◽

Agricultural Drought ◽

Extreme Weather Events ◽

Coefficient Of Determination ◽

Cereal Crops ◽

Drought Indices ◽

Trend Test ◽

Small Scale ◽

The Impact

Increasing temperature and altered precipitation patterns lead to the extreme weather events such as drought and flood, which severely affects the agricultural production. This study was aimed to assess the impact of climate change-induced agricultural drought on four cereal crops in Bako Tibe District. Time-series climate and crop yield data, recorded from 1989 to 2018, were acquired from NASA’s data portal and Bako Research Institute. The changes in temperature and precipitation were analyzed using Mann Kendall trend test. The agricultural drought index was analyzed using R-software. The correlation between the selected yield crops and drought indices were evaluated using Pearson correlation coefficient. The results show that trends of seasonal and annual maximum and minimum temperatures were significantly increased (P<0.05). However, seasonal and annual precipitations were insignificantly decreased (P>0.05). Moderate to severe agricultural drought intensities happened four times in the last three decades. These drought spells spatially covered about 36% of the total area of the district. Crop yields and drought indices were significantly correlated at p-values; 0.0034, 0.043, 0.003 and 0.001 for teff, wheat, barley and maize, respectively. The coefficient of determination (R2) values of crop yields were 28.3%, 30.9%, 28.5% and 34.6% for teff, wheat, barley and maize, correspondingly. The study clearly suggests that the increase in temperature and decrease in precipitation enhanced the frequency and intensity of drought events and these impacted the selected crop yields during the past three decades. The map-based results could be used as guides for governmental and non-governmental organizations concerning on drought impact mitigation activities in the district by encouraging farmers to adopt appropriate agricultural technologies, drought tolerant crop varieties and small scale irrigation.

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Exit Slips As Predictor of Academic Performance

Journal of Education, Management and Development Studies ◽

10.52631/jemds.v1i2.31 ◽

2021 ◽

Vol 1 (2) ◽

pp. 52-61

Author(s):

Raymart Basco

Keyword(s):

Academic Performance ◽

Science Achievement ◽

Pearson Correlation ◽

Positive Association ◽

Vital Role ◽

The Self ◽

Coefficient Of Determination ◽

Instructional Objectives ◽

Descriptive Survey ◽

The Impact

Formative assessment plays a vital role in the delivery of quality and relevant education among learners. Data derived from the assessment results provide pieces of evidence for teachers to determine learners who need assistance, advance instructional objectives, track learners’ progress toward those standards, and identify what intervention and support are required. This descriptive-survey research examined the impact of exit slips in predicting intermediate pupils’ science achievement. Seventy-three pupils were involved in the study who were selected through a total sampling. Weighted mean, ranking, standard deviation, mean percentage score, frequency, Pearson correlation coefficient, and coefficient of determination were utilized to process and analyze statistically the data using SPSS. The findings of the study highlighted that exit slips can help learners in their learning since they reflect pupils’ understanding and increase accountability among them. The results revealed that there was a high positive association between the self-rating report and the academic performance of the respondents. The impact of self-reported rating was found significant on the performance of the pupils. Hence, when teachers took necessary and relevant remediation as well as enrichment based on the self-reported rating, academic performance may be improved. It was recommended that teachers may adapt the use of exit slips in their classes to improve academic performance among learners.

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Historical and projected future hydroclimatic risk on seasonal yield in the irrigated rice paddies of Malaysia

10.5194/egusphere-egu21-15844 ◽

2021 ◽

Author(s):

Zed Zulkafli ◽

Nurfarhana Raffar ◽

Mukhtar Jibril Abdi ◽

Amirparsa Jajarmizadeh ◽

Mohamad Shahmi Ahmad Shukri ◽

...

Keyword(s):

Climate Model ◽

Assessment Tool ◽

Rice Yield ◽

Pearson Correlation ◽

Regional Climate ◽

Rice Paddy ◽

Coefficient Of Determination ◽

Wet Season ◽

Regional Climate Model Output ◽

The Impact

Food security is an increasing threat to rice-consuming nations in the face of a changing climate. In this study, we present a framework for analysing&#160; the historical and projecting the future relationship between climate variability and rice yield in the context of weather index insurance. The case study is the Muda rice granary, the largest rice paddy planting area in Malaysia producing approximately 40% of the national output. First, correlation and linear regression are used to explore the response of seasonal rice yield to various average and extreme precipitation, temperature and streamflow-based indices over a 16 year period between 2001 to 2016.&#160; The highest Pearson correlation (r) and coefficient of determination (R2) values were obtained with June minimum temperature in the dry season, and December maximum 1 day precipitation and&#160; January mean streamflow in the wet season. The results suggest that rice yield is most at risk from the impact of hydroclimatic variability and change during the flowering and maturity stages of crop growth. Next, findings from the statistical analysis are integrated with hydro-crop simulation of the 4,515 km2 catchment area, using a calibrated Soil Water Assessment Tool (SWAT) and bias-corrected Regional Climate Model output from the Coordinated Regional Downscaling Experiment for South East Asia (CORDEX-SEA). The output is finally used to construct projected future risk profiles for rice production in the area.&#160;

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CONCEPTUAL UNDERSTANDING AND PROBLEM-SOLVING SKILLS: THE IMPACT OF HYBRID LEARNING ON MECHANICS

EDUPROXIMA : Jurnal Ilmiah Pendidikan IPA ◽

10.29100/eduproxima.v2i2.1626 ◽

2020 ◽

Vol 2 (2) ◽

pp. 67

Author(s):

Yessi Affriyenni ◽

Arif Hidayat ◽

Galandaru Swalaganata

Keyword(s):

Problem Solving ◽

Conceptual Understanding ◽

Pearson Correlation ◽

Hybrid Learning ◽

Coefficient Of Determination ◽

Average Score ◽

Multiple Choice Questions ◽

Problem Solving Skills ◽

The Impact ◽

Linearity Test

Mechanics is a challenging topic not only for the students majoring in physics but also for those who are not majoring in physics. This study aims to discover the correlation between students’ conceptual understanding and problem-solving skills experienced by students who major in natural science. The analysis was conducted after the course had been delivered using the hybrid-learning method. Students’ conceptual understanding was measured using 13 multiple-choice questions while their problem-solving skill was measured using 3 essay questions. The normality, the linearity, and the correlation of the data were analyzed. The data is normally distributed with the average score of students’ conceptual understanding was 83 and the average score of students’ problem-solving skills was 48. The linearity test shows that there is a significant linear correlation between students’ conceptual understanding and problem-solving skills. However, the Pearson Correlation test result shows that there is no significant positive correlation between the two variables with the coefficient of determination was only 15.4%.

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Proton Competition and Free Ion Activities Drive Cadmium, Copper, and Nickel Accumulation in River Biofilms in a Nordic Ecosystem

Environments ◽

10.3390/environments7120112 ◽

2020 ◽

Vol 7 (12) ◽

pp. 112

Author(s):

Vincent Laderriere ◽

Louise-Emmanuelle Paris ◽

Claude Fortin

Keyword(s):

Surface Water ◽

Metal Ion ◽

Metal Content ◽

Metal Accumulation ◽

Anthropogenic Activities ◽

Ion Concentration ◽

Dissolved Metals ◽

Biomonitoring Tool ◽

Water Ph ◽

Decreasing Ph

Biofilms can be used as a biomonitoring tool to determine metal bioavailability in streams affected by mining and other anthropogenic activities. Surface water and biofilm were sampled over two years from rivers located in the vicinity of a mine located in a Nordic ecosystem (Nunavik, Quebec). Biofilm metal content (Cd, Cu, and Ni) as well as a variety of physicochemical properties were determined to examine relationships between metal accumulation and water quality. Among the three metals of interest, copper and nickel had the highest levels of accumulation and cadmium had the lowest. When considering the exposure levels, nickel was the most abundant metal in our sampling sites. Both exposure and accumulation levels were consistent over time. Biofilm metal content was highly correlated to the ambient free metal ion concentration for sites of circumneutral pHs for all three metals. When the surface water pH was below 6, biofilm metal content was much lower than at other sites with similar aqueous metal concentrations of exposure. This apparent protective effect of decreasing pH can be explained by proton competition with dissolved metals for uptake binding sites at the surface of the organisms within the biofilm as described by the Biotic Ligand Model principles. The relationships obtained for Cd and Cu were overlapping those observed in previous publications, indicating strong similarities in metal accumulation processes in biofilms over very large geographical areas. Although more data are needed for Ni, our results show that biofilms represent a promising metal biomonitoring tool.

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Impact of Climate Change on Walnut Production in Biara Sub-District

Journal of Raparin University ◽

10.26750/vol(7).no(4).paper23 ◽

2020 ◽

Vol 7 (4) ◽

pp. 487-506

Author(s):

Pshtiwan Gharib Ghafur ◽

Zhyan Sleman Hama ◽

Khanda Saed Tofiq

Keyword(s):

Climate Change ◽

Regression Analysis ◽

Analytical Method ◽

Pearson Correlation ◽

Effect Of Temperature ◽

Coefficient Of Determination ◽

Impact Of Climate Change ◽

Temperature And Precipitation ◽

Irrigation Projects ◽

The Impact

In this research is conducted about the impact of climate change on walnut production in Biara Sub-district. Descriptive – analytical method was utilized to obtain the proposed objectives by using SPSS – 16. The predominant objective of this analysis is to illustrate the inevitable impact of climate change on the walnut production in 1973-2017. The results on which the study was based on are Pearson Correlation which demonstrates that there is an indirect correlation between temperature and walnut production, and an equivalent relation with precipitation. For instance, in Multiple Regression Analysis, the impact of temperature and precipitation on small walnut trees is 4%, and on medium walnut trees is 25.8%, whereas on big walnut trees it is 24.8%. Moreover, in Coefficient of Determination, the effect of temperature on small walnut trees is 3.4%, on medium and large walnut trees increase to 18.6% and 24.7% respectively. However, precipitation impact is less than 1%, except medium walnut trees is less than 6%. The apparent wide gaps between temperature and precipitation which affects production is due to low topographic elevation and the presence of 82 springs in the study area. Additionally, an increase in temperature, a decrease in precipitation and subfreezing temperatures, in other words, chill dates, in spring time, ultimately leads to an increase in hazardous insects such as stem worms and beetle. These issues could be solved through selecting different varieties of walnuts and planting at higher elevation, construct more irrigation projects and regular irrigation, in particular during drought seasons, improving agricultural facilities and importing sufficient pesticides to tackle walnut trees diseases, is also among the precautionary methods.

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Examining water storage variations as a function of meteorology using GRACE and GLDAS

10.5194/egusphere-egu21-3637 ◽

2021 ◽

Author(s):

Caleb Kelly ◽

Nicholas Hamm ◽

Craig Hancock ◽

Stephen Grebby ◽

Stuart Marsh

Keyword(s):

Surface Water ◽

Water Availability ◽

Meteorological Data ◽

Pearson Correlation ◽

Water Storage ◽

Meteorological Conditions ◽

P Value ◽

Increasing Trend ◽

Terrestrial Water ◽

The Impact

The Upper East Region (UER) of Ghana, located between 10.2&#8211;11.2&#176;N, 1.6&#176;W&#8211;0.03&#176;E, is characterised by a long dry season and annual floods that are exacerbated by the opening of the Bagre Dam in neighbouring Burkina Faso. The UER lies within the Volta Basin, which has been the subject of numerous hydrological studies. The basin spans several jurisdictions with varying meteorological conditions; thus, basin-wide studies may not truly reflect localised dynamics of water storage over the UER. Data from the Gravity Recovery and Climate Experiment (GRACE) mission and hydrological models, e.g., the Global Land Data Assimilation System (GLDAS), have been used for hydrological studies. Nonetheless, GRACE&#8217;s resolution may restrict its application to large areas (&#8805;150,000 km2) or smaller areas with storage variations of &#8805;8 km3, while GLDAS does not model surface water. With this in mind, this research evaluates GRACE and GLDAS for water storage analysis over the UER (~9000 km2).We used the latest mass concentration solution from the Centre for Space Research, GLDAS-NOAH, and the Global Precipitation Measurement (GPM) from April 2002 to June 2017. The long-term mean (2004&#8211;2009) was removed from GPM and NOAH. The GRACE time series was characterised by an increasing trend in terrestrial water storage anomalies (TWSA) (6.2 mm/yr), annual and semi-annual amplitudes of 99.4 mm and 10.5 mm, and annual and semi-annual phases of 39.1&#176; and 13.6&#176;, respectively. The minimum variation (-150.8 mm, -47.4 km3) in TWSA occurred in May 2003, while the maximum (222.3 mm, 69.9 km3) occurred in September 2012, both of which are during the rainy season. Rainfall anomalies showed a declining trend at a rate of 0.25 mm/yr. A Pearson correlation coefficient (r) between rainfall and TWSA revealed a low r = 0.30 (p-value << 0.01 ). Conversely, time-lagged r = 0.60, one and two months after rainfall. The largest (r = 0.66) occurred two months &#160;after rainfall. NOAH-based evapotranspiration anomalies (ETA) indicated a slow, but increasing, trend (0.4 mm/yr). Furthermore NOAH-derived TWSA underestimated storage, yielding a rate of decline of 2.1 mm/yr, which could be due to unmodelled surface water. However, NOAH-derived TWSA were comparatively strongly correlated with rainfall (r = 0.69 and 0.87 at lags 0 and 1). As rainfall is the only source of input to the water balance equation and as rates of ETA suggest conditions in the UER support water loss, these results may indicate a strong contribution to TWSA from the yet unmodelled water from the Bagre Dam.This study was the first to investigate the impact of meteorological conditions on water availability in the UER using GRACE and GLDAS. The results show that GLDAS-NOAH underestimated storage, and that TWSA increased, although this increase is not entirely explained by rainfall. Subsequent experiments will incorporate the contribution of water from the Bagre Dam as well as other meteorological data (e.g., wind speed, humidity) to better explain the differences in those parameters and fully characterise the impact of meteorological conditions on water availability in the UER.&#160;

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