Groundwater Quality Assessment Using Fuzzy-AHP in An Giang Province of Vietnam

Along with rapid population growth in Vietnam, there is an increasing dependence on groundwater for various activities. An Giang province is known to be one of the agricultural intensification areas of The Vietnamese Mekong Delta (VMD). This study aimed to evaluate the spatiotemporal variation of groundwater quality for a period of ten years from 2009 to 2018 in An Giang. The weighted groundwater quality index (GWQI) was developed based on the fuzzy analytic hierarchy process (Fuzzy-AHP) for assigning weighted parameters. The results show that that shallow wells in the Northeast and Southeast regions of An Giang were mostly categorized under “bad water” quality with high arsenic (As) concentration over the years partly due to huge amounts of sediment deposition in monsoon season. Overall, the reason for the poor groundwater quality in An Giang was the combined effect of both natural and human activities. On the other hand, we detected high values of GWQI links with high As concentration in areas where people extract more groundwater for irrigation. Temporal variation of GWQI suggested that groundwater quality at eight wells has improved from 2009 to 2018 in the wet season as compared to the dry season. The reason behind the improvement of groundwater quality during wet season was the decrease in river discharge, which causes less deposition of suspended solids near the flood plains. Moreover, the filling of unused wells can reduce the movement of pollutants from unused wells to groundwater aquifers. Although there was not sufficient evidence to show the relationship between As and sediment concentration, the temporal reduction trend in river discharge and suspended solids was detected in An Giang. The understanding of groundwater quality can help policymakers protect and manage limited water resources in the long-term.

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Evaluating the groundwater quality of Damodar Fan Delta (India) using fuzzy-AHP MCDM technique

Applied Water Science ◽

10.1007/s13201-021-01408-2 ◽

2021 ◽

Vol 11 (7) ◽

Author(s):

Sadik Mahammad ◽

Aznarul Islam

Keyword(s):

Water Quality ◽

Groundwater Quality ◽

Fuzzy Ahp ◽

Poor Quality ◽

Quality Parameters ◽

Analytic Hierarchy ◽

Fan Delta ◽

Quality Water ◽

Calcium Magnesium ◽

Groundwater Quantity

AbstractIn recent years, groundwater pollution has become increasingly a serious environmental problem throughout the world due to increasing dependency on it for various purposes. The Damodar Fan Delta is one of the agriculture-dominated areas in West Bengal especially for rice cultivation and it has a serious constraint regarding groundwater quantity and quality. The present study aims to evaluate the groundwater quality parameters and spatial variation of groundwater quality index (GWQI) for 2019 using the fuzzy analytic hierarchy process (FAHP) method. The 12 water quality parameters such as pH, TDS, iron (Fe−) and fluoride (F−), major anions (SO42−, Cl−, NO3−, and HCO3−), and cations (Na+, Ca2+, Mg2+, and K+) for the 29 sample wells of the study area were used for constructing the GWQI. This study used the FAHP method to define the weights of the different parameters for the GWQI. The results reveal that the bicarbonate content of 51% of sample wells exceeds the acceptable limit of drinking water, which is maximum in the study area. Furthermore, higher concentrations of TDS, pH, fluoride, chloride, calcium, magnesium, and sodium are found in few locations while nitrate and sulfate contents of all sample wells fall under the acceptable limits. The result shows that 13.79% of the samples are excellent, 68.97% of the samples are very good, 13.79% of the samples are poor, and 3.45% of the samples are very poor for drinking purposes. Moreover, it is observed that very poor quality water samples are located in the eastern part and the poor water wells are located in the northwestern and eastern part while excellent water quality wells are located in the western and central part of the study area. The understanding of the groundwater quality can help the policymakers for the proper management of water resources in the study area.

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The Response of Turbidity Maximum to Peak River Discharge in a Macrotidal Estuary

Water ◽

10.3390/w13010106 ◽

2021 ◽

Vol 13 (1) ◽

pp. 106

Author(s):

Yuhan Yan ◽

Dehai Song ◽

Xianwen Bao ◽

Nan Wang

Keyword(s):

River Discharge ◽

Recovery Time ◽

Morphological Evolution ◽

Spring Tide ◽

River Estuary ◽

Sediment Concentration ◽

Ocean Model ◽

Turbidity Maximum ◽

Sediment Supply ◽

Three Dimensional Model

The Ou River, a medium-sized river in the southeastern China, is examined to study the estuarine turbidity maximum (ETM) response to rapidly varied river discharge, i.e., peak river discharge (PRD). This study analyzes the difference in ETM and sediment transport mechanisms between low-discharge and PRD during neap and spring tides by using the Finite-Volume Community Ocean Model. The three-dimensional model is validated by in-situ measurements from 23 April to 22 May 2007. In the Ou River Estuary (ORE), ETM is generally induced by the convergence between river runoff and density-driven flow. The position of ETM for neap and spring tides is similar, but the suspended sediment concentration during spring tide is stronger than that during neap tide. The sediment source of ETM is mainly derived from the resuspension of the seabed. PRD, compared with low-discharge, can dilute the ETM, but cause more sediment to be resuspended from the seabed. The ETM is more seaward during PRD. After PRD, the larger the peak discharge, the longer the recovery time will be. Moreover, the river sediment supply helps shorten ETM recovery time. Mechanisms for this ETM during a PRD can contribute to studies of morphological evolution and pollutant flushing.

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Limnology of Merbok estuary, Kedah, Malaysia

Bangladesh Journal of Zoology ◽

10.3329/bjz.v41i1.23294 ◽

2015 ◽

Vol 41 (1) ◽

pp. 13-19

Author(s):

Kaniz Fatema ◽

Wan Maznah Wan Omar ◽

Mansor Mat Isa

Keyword(s):

Water Quality ◽

Dissolved Oxygen ◽

Suspended Solids ◽

Total Suspended Solids ◽

Quality Parameters ◽

The Other ◽

Wet Season ◽

Hand Temperature ◽

Do Concentration ◽

Merbok Estuary

Water quality in three different stations of Merbok estuary was investigated limnologically from October, 2010 to September, 2011. Water temperature, transparency and total suspended solids (TSS) varied from 27.45 - 30.450C, 7.5 - 120 cm and 10 -140 mg/l, respectively. Dissolved Oxygen (DO) concentration ranged from 1.22-10.8 mg/l, while salinity ranged from 3.5-35.00 ppt. pH and conductivity ranged from 6.35 - 8.25 and 40 - 380 ?S/cm, respectively. Kruskal Wallis H test shows that water quality parameters were significantly different among the sampling months and stations (p<0.05). This study revealed that DO, salinity, conductivity and transparency were higher in wet season and TSS was higher in dry season. On the other hand, temperature and pH did not follow any seasonal trends.Bangladesh J. Zool. 41(1): 13-19, 2013

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Suspended sediment dynamics during the inter-monsoon season in the subaqueous Mekong Delta and adjacent shelf, southern Vietnam

Journal of Asian Earth Sciences ◽

10.1016/j.jseaes.2012.10.008 ◽

2014 ◽

Vol 79 ◽

pp. 509-519 ◽

Cited By ~ 24

Author(s):

Daniel Unverricht ◽

Thanh Cong Nguyen ◽

Christoph Heinrich ◽

Witold Szczuciński ◽

Niko Lahajnar ◽

...

Keyword(s):

Suspended Sediment ◽

Monsoon Season ◽

Mekong Delta ◽

Sediment Dynamics ◽

Southern Vietnam

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Medium-range mid-tropospheric transport of ozone and precursors over Africa: two numerical case studies in dry and wet seasons

Atmospheric Chemistry and Physics ◽

10.5194/acp-7-5357-2007 ◽

2007 ◽

Vol 7 (20) ◽

pp. 5357-5370 ◽

Cited By ~ 42

Author(s):

B. Sauvage ◽

F. Gheusi ◽

V. Thouret ◽

J.-P. Cammas ◽

J. Duron ◽

...

Keyword(s):

Mirror Symmetry ◽

Monsoon Season ◽

Trade Flow ◽

Lower Troposphere ◽

Hadley Cell ◽

Scale Model ◽

Wet Season ◽

Airborne Measurements ◽

Ozone Precursors ◽

Low Level

Abstract. A meso-scale model was used to understand and describe the dynamical processes driving high ozone concentrations observed during both dry and monsoon season in monthly climatologies profiles over Lagos (Nigeria, 6.6° N, 3.3° E), obtained with the MOZAIC airborne measurements (ozone and carbon monoxide). This study focuses on ozone enhancements observed in the upper-part of the lower troposphere, around 3000 m. Two individual cases have been selected in the MOZAIC dataset as being representative of the climatological ozone enhancements, to be simulated and analyzed with on-line Lagrangian backtracking of air masses. This study points out the role of baroclinic low-level circulations present in the Inter Tropical Front (ITF) area. Two low-level thermal cells around a zonal axis and below 2000 m, in mirror symmetry to each other with respect to equator, form near 20° E and around 5° N and 5° S during the (northern hemisphere) dry and wet seasons respectively. They are caused by surface gradients – the warm dry surface being located poleward of the ITF and the cooler wet surface equatorward of the ITF. A convergence line exists between the poleward low-level branch of each thermal cell and the equatorward low-level branch of the Hadley cell. Our main conclusion is to point out this line as a preferred location for fire products – among them ozone precursors – to be uplifted and injected into the lower free troposphere. The free tropospheric transport that occurs then depends on the hemisphere and season. In the NH dry season, the AEJ allows transport of ozone and precursors westward to Lagos. In the NH monsoon (wet) season, fire products are transported from the southern hemisphere to Lagos by the southeasterly trade that surmounts the monsoon layer. Additionally ozone precursors uplifted by wet convection in the ITCZ can also mix to the ones uplifted by the baroclinic cell and be advected up to Lagos by the trade flow.

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THE IMPACT OF AGRICULTURAL PRACTICES ON GROUNDWATER QUALITY: A CRITICAL STUDY BASED ON NAVITHANVELI DS DIVISION IN AMPARA DISTRICT IN SRI LANKA

International Journal of Research -GRANTHAALAYAH ◽

10.29121/granthaalayah.v5.i9.2017.2195 ◽

2017 ◽

Vol 5 (9) ◽

pp. 36-43 ◽

Cited By ~ 1

Author(s):

Nijamir K ◽

Kaleel MIM

Keyword(s):

Groundwater Quality ◽

Groundwater Contamination ◽

Agricultural Practices ◽

Primary Objective ◽

Phosphate Concentration ◽

Critical Study ◽

Wet Season ◽

Traditional Agricultural Practices ◽

The Impact ◽

Chemical Testing

This study was proceeded to identify the groundwater contamination based on the primary and secondary objectives. The primary objective is “identifying the groundwater contamination by the utilization of agro-chemicals, and the secondary objectives are “finding out Nitrate and Phosphate concentration to identify the Groundwater quality depletion by the chemical testing, identifying adverse agricultural practices and to make awareness among agro-chemical users by inducing traditional agricultural practices and recommend favorable solutions to the groundwater oriented problems in study area. For this study five parameters such as NO3, PO4, EC, pH and Turbidity were analyzed. All the parameters varied from wet season to dry season. Particularly, NO3 and PO4 concentration has deviated from both seasons. The conclusion of the study is that the application of the agrochemicals has impacted on the groundwater quality drastically.

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Groundwater Quality Issues and Challenges for Drinking and Irrigation Uses in Central Ganga Basin Dominated with Rice-Wheat Cropping System

Water ◽

10.3390/w13172344 ◽

2021 ◽

Vol 13 (17) ◽

pp. 2344

Author(s):

Sumant Kumar ◽

Manish Kumar ◽

Veerendra Kumar Chandola ◽

Vinod Kumar ◽

Ravi K. Saini ◽

...

Keyword(s):

Drinking Water ◽

Groundwater Quality ◽

Irrigation Water ◽

Monsoon Season ◽

Ground Surface ◽

Cropping System ◽

Ganga Basin ◽

Gangetic Plain ◽

Study Region ◽

Drinking And Irrigation

Increased population and increasing demands for food in the Indo-Gangetic plain are likely to exert pressure on fresh water due to rise in demand for drinking and irrigation water. The study focuses on Bhojpur district, Bihar located in the central Ganga basin, to assess the groundwater quality for drinking and irrigation purpose and discuss the issues and challenges. Groundwater is mostly utilized in the study area for drinking and irrigation purposes (major crops sown in the area are rice and wheat). There were around 45 groundwater samples collected across the study region in the pre-monsoon season (year 2019). The chemical analytical results show that Ca2+, Mg2+ and HCO3− ions are present in abundance in groundwater and governing the groundwater chemistry. Further analysis shows that 66%, 69% and 84% of the samples exceeded the acceptable limit of arsenic (As), Fe and Mn respectively and other trace metals (Cu, Zn, Pb, Cd) are within the permissible limit of drinking water as prescribed by Bureau of Indian Standard for drinking water. Generally, high as concentration has been found in the aquifer (depth ranges from 20 to 40 m below ground surface) located in proximity of river Ganga. For assessing the irrigation water quality, sodium adsorption ratio (SAR) values, residual sodium carbonate (RSC), Na%, permeability index (PI) and calcium alteration index (CAI) were calculated and found that almost all the samples are found to be in good to excellent category for irrigation purposes. The groundwater facie has been classified into Ca-Mg-HCO3 type.

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The Morphological Measurement Variations of Periophthalmus chrysospilos along the Coastline in the Mekong Delta

VNU Journal of Science Natural Sciences and Technology ◽

10.25073/2588-1140/vnunst.5245 ◽

2021 ◽

Author(s):

Le Trung Hieu ◽

Dinh Minh Quang ◽

Hua Van U ◽

Nguyen Huu Duc Ton

Keyword(s):

Morphological Variation ◽

Body Height ◽

Mekong Delta ◽

Wet Season ◽

Morphological Variations ◽

Total Length ◽

Fish Samples ◽

Eye Diameter ◽

And Gender ◽

Study Sites

This study provided data on morphological variation in Periophthalmus chrysospilos. The study was carried out in four provinces from Tra Vinh to Soc Trang, Bac Lieu and Ca Mau. Fish samples were collected by hand-catching over 12 months from April 2020 to March 2021. Analysed results of a collection of 1,031 individuals (508 females and 523 males) showed that the total length (TL) and weight (W) of the female Periophthalmus chrysospilos were higher than that of the male, higher in the wet season than in the dry season and gradually increased from Tra Vinh to Ca Mau. Besides, the total length and weight of fish were also influenced by the interaction of season ´ site and gender ´ site. In addition, the morphological variation of this species such as eye diameter (ED), eye distance (DE), body height (BD), head length (HL) and taxonomic ratios such as HL/TL, BD/TL, ED/HL, DE/HL was gender, seasonal fluctuations and study sites. These morphological variations and ratios were also influenced by interactions season ´ site interactions. The findings contributed further information to fish identification and the ecological adaptation understanding of this species.

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Quantifying Suspended Sediment using Acoustic Doppler Current Profiler in Tidung Island Seawaters

Pertanika Journal of Science and Technology ◽

10.47836/pjst.29.1.21 ◽

2021 ◽

Vol 29 (1) ◽

Author(s):

Henry Munandar Manik ◽

Randi Firdaus

Keyword(s):

Water Column ◽

Suspended Sediment ◽

Suspended Solids ◽

Acoustic Doppler Current Profiler ◽

Sediment Concentration ◽

In Situ Measurement ◽

Ocean Current ◽

Echo Intensity ◽

Current Profiler

Tidung Island, located near Jakarta Bay, is a tourism and conservation area. It is necessary to keep these seawaters unpolluted. To calculate the level of pollution, it is necessary to know the sediment concentration. Quantifying concentration suspended sediment is important for knowledge of sediment transport. Researchers usually use water sample analysis and optical method for quantifying suspended sediment in seawater. Less accuracies of these methods are due to under sample of seawater and the existence of biological fouling. One promising method to measure concentration of suspended sediment is using Acoustic Doppler Current Profiler (ADCP). ADCP is usually used by oceanographer and hydrographer to measure ocean current. In this research, ADCP with 300 kHz operating frequency was used effectively to measure suspended sediment concentration (SSC) and ocean current simultaneously. The echo intensity received from suspended sediment was computed using sonar equations to quantify SSC. The empirical equation between echo intensity and SSC was found. The SSC value obtained by ADCP was also compared with in situ measurement. The result showed that quantified SSC value obtained by ADCP was nearly equal with SSC obtained from in situ measurement with coefficient correlation of 0.98. The high concentration ranged from 55 mg/L to 80 mg/L at the surface layer to a depth 12 m, moderate concentration ranged from 45 mg/L to 55 mg/L at a depth 12 m to 40 m, and low concentration less than 45 mg/L at a depth greater than 40 m. The distribution of SSC was correlated with ocean current condition. In small currents, suspended solids will settle faster so that the concentration in the water column will decrease. Conversely, if the velocity is high, suspended solids will continue to float carried by the current in the water column so that the concentration is high.

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Seasonal Groundwater Quality Status and Nitrogen Contamination in the Shallow Aquifer System of the Kathmandu Valley, Nepal

Water ◽

10.3390/w11102184 ◽

2019 ◽

Vol 11 (10) ◽

pp. 2184 ◽

Cited By ~ 3

Author(s):

Shakya ◽

Nakamura ◽

Kamei ◽

Shrestha ◽

Nishida

Keyword(s):

Groundwater Quality ◽

Nitrogen Compound ◽

Shallow Aquifer ◽

Kathmandu Valley ◽

Nitrogen Compounds ◽

Wet Season ◽

Aquifer System ◽

Spatially Distributed ◽

Nitrogen Contamination ◽

Dug Well

: The increasing concentration of nitrogen compounds in the groundwater is of a growing concern in terms of human health and groundwater quality. Although an excess of nitrogen compounds in the groundwater of the Kathmandu Valley has been reported, the seasonal variations of the fate of the nitrogen compounds and their relationships to the subsurface sediments are unknown. In this study, spatially distributed shallow dug well samples were collected during both the dry and wet seasons of 2016, and the nitrogen compound, chloride (Cl−), and iron (Fe2+) concentrations were analyzed. Two shallow dug wells and one deep tube well were monitored monthly for 2 years. Although NH4-N concentrations were similar in the clay-dominated areas during both seasons (1 and 0.9 mg-N/L), they were lower in the gravel-dominated areas during wet season (1.8 > 0.6 mg-N/L). The NO3-N concentration differed depending upon the soil type which increased during the wet season (clay 4.9 < 13.6 mg-N/L and gravel 2.5 < 6.8 mg-N/L). The Fe2+ concentration, however, was low during the wet season (clay 2.7 > 0.4 mg/L and gravel 2.8 > 0.3 mg/L). Long-term analysis showed higher fluctuation of nitrogen compounds in the gravel-bearing areas than in the clay-bearing areas.

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