scholarly journals Application of multi hydrochemical indices for spatial groundwater quality assessment: Ziway Lake Basin of the Ethiopian Rift Valley

Author(s):  
Abraham Mechal ◽  
Hassen Shube ◽  
Tewodros Rango ◽  
Kristine Walraevens ◽  
Steffen Birk

Abstract The Ethiopian Rift Valley (ERV), which is characterized by arid and semi-arid climate, groundwater is the most important water resource used for drinking and irrigation purposes. However, in the region people are suffering from severe water scarcity exacerbated by climate effect. Besides water availability, endemic water quality issues are critical and affect the suitability of the water and human health risks. The present study evaluates the suitability of groundwater for drinking and agricultural purposes in the Ziway Lake Basin (ZLB) of the ERV. Groundwater used for drinking contains multiple inorganic contaminants in levels that surpass the World Health Organization recommended limits. The most frequent of these violations were for Na+, K+, HCO3-, F- and few samples for Mn, As, U, Pb and Mo. The modeled Drinking Water Quality Index (DWQI) values of the groundwater show wide variation ranging from 12.7 (Excellent category) to 714 (Unsuitable category) with mean value of 94. Likewise, Irrigation Water Quality Index (IWQI) computed by considering EC, SAR, Na%, RSC and PI of the groundwater vary from 13.2 to 520 with mean value of 106. Both DWQI and IWQI value suggest that groundwater is generally of Excellent quality for drinking and irrigation use in the headwater regions of the ZLB and progressively becomes extremely Unsuitable towards the rift floor. The exceptionally high DWQI values to the west of Lake Ziway is mainly associated with the co-occurrence of multiple toxic elements from a groundwater from the Quaternary sediments and rhyolitic volcanic aquifers.

2021 ◽  
Vol 11 (9) ◽  
Author(s):  
Tamru Tesseme Aragaw ◽  
Gopalakrishnan Gnanachandrasamy

AbstractGroundwater is the major resource for drinking and irrigation purposes in urban areas of Abaya-Chemo sub-basin of Great Rift Valley, Ethiopia. There is an incredible increase in demand in the sub-basin for good-quality groundwater resources. However, the exhaustive irrigation and rapid urbanization has posed a serious threat to groundwater quality in the urban districts of sub-basin like Arba Minch town. The aim of the study was to evaluate the groundwater quality status and to map their spatial distribution with respect to the suitability for drinking and irrigation purposes in Arba Minch town, Ethiopia. Fourteen bore well samples were examined for geochemical variations and groundwater qualities. The spatial distribution maps of quality parameters were prepared using the kriging method in ArcGIS 10.3. Drinking water quality index, sodium adsorption ratio (SAR), percentage sodium (Na%), residual sodium carbonate (RSC), and permeability index (PI) were considered for drinking and irrigation suitability assessment. Comparison of the hydrochemical results with the World Health Organization (WHO) and Ethiopian drinking water standards (ES) and various classifications revealed that the current status of the groundwaters is suitable for drinking and irrigation purposes except for a few sites at the northwestern part of the study area. The WQI results revealed that 7% and 64% of samples fall from excellent to good classes for drinking categories. Irrigation indices also demonstrated that 80% of samples fall in good classes for irrigation purposes. About 75 percent of samples belong to Ca–Mg-HCO3 facies, and the reaming samples belong to Ca–Mg–Cl facies. The results of the study concluded that the proposed approach is reliable and efficient for the groundwater pollution status evaluation and can also be applied in decision making for effective groundwater resources monitoring in the study area.


2020 ◽  
Vol 9 (1) ◽  
pp. 174-187
Author(s):  
Falowo Olusola Olumuyiwa ◽  
Ojo Olajumoke Olayemi

An assessment of the ground water quality was carried out in Ese Odo local government area of Ondo State, southwestern Nigeria. The study was aimed at examining the various samples of ground water and the quality of the ground water as it relates to drinking and irrigation purposes. Forty-Five ground water samples were taken from boreholes and open wells and analyzed for physical, chemical and biological properties. The results were compared with World Health Organization standards. The usefulness of these parameters in predicting ground water quality characteristics were studied and water quality index was determined from these parameters. In assessing the water for irrigation uses, indices such as percent (%Na), sodium adsorption ratio (SAR), residual sodium carbonate (RSC), permeability index (PI), Kelly’s ratio (KR), magnesium ratio (MR), equivalent salinity concentration (ESC) and Wilcox plot were used.   The result obtained shows that the water studied has a mean value of 2.8 NTU for turbidity, 7.3 for pH, 294 μS/cm for electrical conductivity, 52mg/L for total dissolved solids, temperature 28.3°C, total hardness 41 mg/L, chloride 38.3 mg/L, calcium 15.8 mg/L, 5.64 mg/L for magnesium, nitrate 1.47mg/L, sulphate 51.7 mg/L, bicarbonate 15mg/L. Zinc, iron, manganese have mean values less than 1mg/L. The results indicated all the physicochemical parameters are within the recommended levels set by World Health Organization (WHO). Although traces of heavy metal and mineral oil contaminations are observed some of the samples. All the samples are plotted on the “Excellent irrigation class” of Wilcox plot with good/excellent irrigation indices. Consequently, the groundwater in the study area is good and suitable for drinking and irrigation purposes.


2021 ◽  
Vol 20 (1) ◽  
pp. 77-85
Author(s):  
Ekrem Mutlu ◽  
◽  
Naime Arslan ◽  
Cem Tokatli ◽  
◽  
...  

Aim of the study: In the present study, the spatial – temporal variations of water quality in Boyalı Pond were analyzed. Water Quality Index (WQI) based on the World Health Organization's standards specified for drinking water, and Water Quality Control Regulations in Turkey (WQCR), as well as certain multi-statistical methods, were used in analyzing the water quality. Material and methods: Water samples were collected from 5 stations selected in the lake on monthly basis in 2019 and 30 water quality parameters were measured in total. Water Quality Index (WQI), Factor Analysis (FA), and Cluster Analysis (CA) were used in order to determine the differences between the spatial and temporal quality levels and to classify the investigated locations. Results and conclusions: According to data observed, Boyalı Dam Lake was found to have Class I and Class II water quality in general the WQI results obtained suggested that, although the water quality was found to significantly decrease in summer months, the reservoir was found to have an "A Grade – Excellent" water quality (<50) in all the months and stations analyzed here. WQI values recorded in the dam lake ranged between 16.4 and 27.8 and the detected limnologic parameters did not exceed the standards specified for drinking water in any of the investigated months and stations (<50 for WQI). As a result of FA, 3 factors explained 88.9% of total variances and as a result of CA, 2 statistical clusters were formed.


2021 ◽  
Vol 11 (3) ◽  
Author(s):  
Zemed Menberu ◽  
Beshah Mogesse ◽  
Daniel Reddythota

AbstractLake Hawassa is one of the major Ethiopian Rift Valley Lakes having an endorheic basin system. The surrounding community makes use of the lake water for the multiple purposes of irrigation, domestic water supply, recreation and fish harvesting. The aim of the present study was to ascertain the water quality of the lake in terms of water quality indices (WQI) and its health over a period of three months covering both dry and wet seasons. Overall, the water quality of Lake was unfit and bad as per the weighted arithmetic method (120.06–228.29) and modified Bascarón water quality index (MBWQI) methods (26.81–33.89), respectively. However, the quality was indicated as marginal, as per the Canadian Council of Ministers of the Environment (CCME) water quality index method (44.2–51.1). On average, the lake was under the hypertrophic stage as per the standard based on the results of Secchi depth and nutrient concentration. The current study showed the lake being unfit for all-purposes as per WAWQI range (> 100). According to the physicochemical and biological parameters, of the lake, it requires mitigation measures to control Eutrophication and pollutants inflow.


2010 ◽  
Vol 61 (8) ◽  
pp. 1987-1994 ◽  
Author(s):  
A. M. Jinturkar ◽  
S. S. Deshmukh ◽  
S. V. Agarkar ◽  
G. R. Chavhan

The paper proposes fuzzy logic model that deals with the physico-chemical water analysis of ground water of Chikhli town for determination of Water Quality Index (WQI). The study was carried by collection of ground water samples from about eleven hand pumps located in this town. Ground water quality is studied by systematic collection and analysis of samples. The fuzzy logic is used for the deciding the water quality index on the basis of which, water quality rankings are given to determine the quality of water. The Water Quality Index presented here is a unitless number ranging from 1 to 10. A higher number is indicative of better water quality. Around 81% of samples were found suitable for drinking purpose. It is also observed that all the parameters fall within the permissible limits laid by WHO, ISI, and ICMR, except Total Hardness, Calcium and Magnesium. The quality parameters were compared with standards laid by the World Health Organization (WHO), Indian Standards Institute (ISI) and Indian Council of Medical Research (ICMR) for drinking water quality.


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