Physicochemical Characterization of Waters in Aquifer AQ2 of the Pointe-Noire Region: Application of Multivariate Statistical Analysis Methods
Frederic Balounta Ngoma,
Christian Tathy,
Romain Richard Niere,
Laurent Matini
Issue:
Volume 11, Issue 1, February 2022
Pages:
1-13
Received:
20 January 2022
Accepted:
14 February 2022
Published:
25 February 2022
Abstract: Located on the Atlantic coast, the city of Pointe-Noire is the economic capital of the Republic of Congo. It enjoys strong industrial activity, particularly oil, with the presence of a refinery and onshore drilling in its surroundings. The steady growth of its population leads to an increase in its drinking water supply needs, produced mainly from the exploitation of its aquifer system. Thus, in view of the growth of its human activities, the interest of permanent monitoring of the quality of its groundwater is becoming more and more great. The present study aims to assess the physicochemical quality of the groundwater in the AQ2 aquifer of the Pointe-Noire region during the period from 2017 to 2020, and to understand the processes that are at the origin of the mineralization of these waters. To this end, we obtained from the water supply company, La Congolaise Des Eaux (LCDE) seventy-five (75) water analysis reports bulletins representing the average values of thirteen (13) physicochemical parameters in each of the 75 boreholes used for this study so as to homogeneously cover the entire city. The Piper diagram revealed that the waters are dominated by three types of facies: K-Na-Cl, Mg-Ca-SO4-Cl and Mg-Ca-HCO3. The presence of the K-Na-Cl facies is due to the high levels of chlorides and sodium in the water-rock. The Principal Component Analysis (PCA) indicates that the mineralization of these waters results in the hydrolysis of silicate minerals. The Ascending Hierarchical Classification (AHC) analysis made it possible to determine the parameters that categorize the different classes from 2017 to 2020, these are TDS, EC and TH and to a lesser extent Ca2+, Mg2+, HCO3-and TAC. Overall, the quality of the groundwater is good according to standards WHO, but in some cases requires specific treatment before supply.
Abstract: Located on the Atlantic coast, the city of Pointe-Noire is the economic capital of the Republic of Congo. It enjoys strong industrial activity, particularly oil, with the presence of a refinery and onshore drilling in its surroundings. The steady growth of its population leads to an increase in its drinking water supply needs, produced mainly from ...
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Suggestion of Classification Method for Agricultural Drought Using Groundwater Level Change
Chan-Duck Jeong,
Byung-Sun Lee,
Gyu-Sang Lee,
Jun-Kyum Kim,
Sung-Ho Song
Issue:
Volume 11, Issue 1, February 2022
Pages:
14-29
Received:
17 February 2022
Accepted:
14 March 2022
Published:
23 March 2022
Abstract: Since weather factors such as precipitation and temperature etc. show repeated patterns every year, it can be said that future changes can be predicted by analyzing past weather data. Therefore, when a drought occurs, the groundwater level is also lowered, so it can be seen that a change in the groundwater level can represent a drought. Like precipitation, groundwater level changes also have a high correlation with drought, so many researchers use SGI (standardized groundwater level index) to which the SPI (standardized precipitation index) method is applied to evaluate the severity of drought and predict trends. However, these approaches have the limitations to indicate the real groundwater system because the drought grades for the entire area are defined with the observation data of a single monitoring well without surrounding influences. When analyzing groundwater level fluctuations to understand the correlation with drought, it is necessary to calculate and apply the actual groundwater level that reflects groundwater use interference. Therefore, in this study, based on the long-term groundwater level data at 162 monitoring well installed before 2015 in Korea, the characteristics of groundwater level changes were analyzed and compared with the period of agricultural drought over the past five years. From the results, it can be confirmed that agricultural drought in regions is classified using the percentile of the SPI method by conducting a frequency analysis that the current groundwater level increase or decrease compared to the past average groundwater level.
Abstract: Since weather factors such as precipitation and temperature etc. show repeated patterns every year, it can be said that future changes can be predicted by analyzing past weather data. Therefore, when a drought occurs, the groundwater level is also lowered, so it can be seen that a change in the groundwater level can represent a drought. Like precip...
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