This study focuses on the geochemical and bacteriological investigation of surface and ground water in the Bamoun plateau (Western-Cameroon). During the period from September 2013 to August 2014, 71 samples were colle...This study focuses on the geochemical and bacteriological investigation of surface and ground water in the Bamoun plateau (Western-Cameroon). During the period from September 2013 to August 2014, 71 samples were collected from two springs, one borehole, four wells and the Nchi stream for analysis of major elements. In order to obtain the characteristics of the various species of bacteria, 7 samples were selected. The analytical method adopted for this study is the conventional hydrochemical technic and multivariate statistical analysis, coupled with the hydrogeochemical modelling. The results revealed that, water from the zone under study are acidic to basic, very weakly to weakly mineralized. Four types of water were identified: 1) CaMg-HCO<sub>3</sub>;2) CaMg-Cl-SO<sub>4</sub>;3) NaCl-SO<sub>4</sub> and 4) NaK-HCO<sub>3</sub>. The major elements were all listed in the World Health Organization guidelines for drinking water quality, except for nitrates which was found at a concentration > 50 mg /l <span style="white-space:nowrap;">NO<sup>-</sup><sub style="margin-left:-7px;">3</sub> </span>in the borehole F401. As for the hydrobiological aspect, the entire sample contained all the bacteriological species except for spring S301 and well P401. According to the hydrogeochemical modelling, the Gibbs model and multivariate statistical tests, the quality of surface and ground water of the Foumban locality is influenced by two important factors: 1) the natural factors characterized by the water-rock interaction, evapotranspiration/crystallization, 2) the anthropogenic factors such as: uncontrolled discharges of liquid and solid effluents of all kinds and without any prior treatment within the ground and the strong urbanization accompanied by lack of sanitation and insufficient care.展开更多
The problem of groundwater supply in the Bamun plateau situated in the Cameroon Volcanic Line exists and no proper solution has been found so far. This investigation intends to find the suitable groundwater potential ...The problem of groundwater supply in the Bamun plateau situated in the Cameroon Volcanic Line exists and no proper solution has been found so far. This investigation intends to find the suitable groundwater potential zones by overlaying the geomorphologic map, lineament map, lineament density map and lithological map, using visual interpretation of Landsat imagery. The results reveal that about 1921 structural elements, ranging in size, from 30 m to 5.845 km with an average length of 671 m in the field. The total length of the mapped lineaments is approximately 1289 km. The most important lineament (5.845 km length) diagonally crosses the study area in the direction NNE-SSW. In addition to this trend, all others are smaller than 14 km. More than 92% of lineaments are less than 5 km in size and only 1.3% of them are larger than 10 km. Small lineaments are thus the most numerous. According to their directions, the lineaments listed are grouped into 18 directional classes of 10-degree intervals. The rosette of their directions highlights the preferred directions NE-SW, N-S, E-W, NNE-SSW and ENE-WSW. Most of the lineaments clusters in the central part of the area are N20<span style="white-space:nowrap;">°</span> - 30<span style="white-space:nowrap;">°</span>E and N60<span style="white-space:nowrap;">°</span> - 70<span style="white-space:nowrap;">°</span>E trending lineaments. In this study, the NE-SW trend dominates the structural trend followed by NW-SE and N-S. This can be an indication of the directions of groundwater movement in the area. Alluvial plain and valley have moderate to very good groundwater potential that occurs all over the study area. Porosity of the volcanic rocks varies greatly, but it is everywhere more porous than the underlying, unweathered bedrock. There are essentially three classes (low, average and high) of groundwater potential zones. Hight potential zones are observed around the localities of the Khogham, Mbatpit and Mbam massifs on the one hand and Manswen, Njikwop, Mfelap, Foumban, Njindaré, Nkoundem and Ngwen jigoumbé localities on the other hand. About 13% of the area has good groundwater potential around the mountains while 58% is moderately good which corresponds to high to moderate lineament densities situated at average altitude 1200 m and about 31% of the area has poor groundwater potential corresponding to low lineament density areas. Moreover, this work has helped develop a detailed lineament map that can be used for mining and hydrological prospecting campaigns.展开更多
The present work focuses on the volcanic basement rock geochemistry of Mount Makabaï(MarouaCameroon city)in relation to groundwater geochemistry.Investigations were centered on an approach involving an associatio...The present work focuses on the volcanic basement rock geochemistry of Mount Makabaï(MarouaCameroon city)in relation to groundwater geochemistry.Investigations were centered on an approach involving an association of several methods such as geological cartography,hydrogeology,and geochemistry.Three rock samples,four disturbed soil samples,three undisturbed soil samples,and 20 samples of groundwater in 10 wells were collected during fieldwork and prepared for laboratory analyses.Bedrocks exhibit porphyritic,aphyric,and subaphiric textures.The phenocryst phases are mainly olivine,clinopyroxene,and plagioclase.Based on whole rock major element chemical compositions,the Makabaï samples,plotted on Na_(2)O+K_(2)O versus SiO_(2)diagram,are mugearite,hawaiite,and basalt.The ratio of(MgO+CaO)/(Na_(2)O+K_(2)O)exceeds unity and shows dominance of alkaline Earth metals(MgO:2.99-4.48%;CaO:6.19-9.80%)relatively to alkali metals(Na_(2)O:2.27-4.46%;K_(2)O:2.09-2.51%).Exchangeable base contents are high,mostly represented by Ca and Mg,whose contents vary from 14.6 to 35.28 cmol(+)kg^(-1)and from 3.28 to9.48 cmol(+)kg^(-1)respectively.The CECclayis likewise high,fluctuating between 116.80 and181.38 cmol(+)kg^(-1),values in line with the presence of 2:1 clay minerals represented in the study area by montmorillonite.In the water samples,the Ca2+and Na+contents are generally higher than K^(+)and Mg^(2+),reflecting the relative abundance of Na_(2)O and CaO oxides to K_(2)O and MgO oxides in rocks where different waters were sampled.The waters of Makabaï are acidic to neutral(6.3≤pH≤7.4)and weakly to highly mineralized(110.0≤EC≤1190.0μS/cm).Hydro-geochemical classification by using the Piper diagram revealed two water types:(1)CaMg-HCO_(3)(40%)and(2)CaMg-Cl or CaMg-SO4(60%).The average content of ions in all the analyzed samples was HCO_(3)^(-)>>NO_(3)^(-)>SO_(4)^(2-)>Cl-for anions and Ca^(2+)>>Mg^(2+)>Na^(+)>K^(+)for cations.Major mechanisms governing ionic constituents of groundwater in the study area are water-rock interactions,silicate weathering,and ion exchange.展开更多
文摘This study focuses on the geochemical and bacteriological investigation of surface and ground water in the Bamoun plateau (Western-Cameroon). During the period from September 2013 to August 2014, 71 samples were collected from two springs, one borehole, four wells and the Nchi stream for analysis of major elements. In order to obtain the characteristics of the various species of bacteria, 7 samples were selected. The analytical method adopted for this study is the conventional hydrochemical technic and multivariate statistical analysis, coupled with the hydrogeochemical modelling. The results revealed that, water from the zone under study are acidic to basic, very weakly to weakly mineralized. Four types of water were identified: 1) CaMg-HCO<sub>3</sub>;2) CaMg-Cl-SO<sub>4</sub>;3) NaCl-SO<sub>4</sub> and 4) NaK-HCO<sub>3</sub>. The major elements were all listed in the World Health Organization guidelines for drinking water quality, except for nitrates which was found at a concentration > 50 mg /l <span style="white-space:nowrap;">NO<sup>-</sup><sub style="margin-left:-7px;">3</sub> </span>in the borehole F401. As for the hydrobiological aspect, the entire sample contained all the bacteriological species except for spring S301 and well P401. According to the hydrogeochemical modelling, the Gibbs model and multivariate statistical tests, the quality of surface and ground water of the Foumban locality is influenced by two important factors: 1) the natural factors characterized by the water-rock interaction, evapotranspiration/crystallization, 2) the anthropogenic factors such as: uncontrolled discharges of liquid and solid effluents of all kinds and without any prior treatment within the ground and the strong urbanization accompanied by lack of sanitation and insufficient care.
文摘The problem of groundwater supply in the Bamun plateau situated in the Cameroon Volcanic Line exists and no proper solution has been found so far. This investigation intends to find the suitable groundwater potential zones by overlaying the geomorphologic map, lineament map, lineament density map and lithological map, using visual interpretation of Landsat imagery. The results reveal that about 1921 structural elements, ranging in size, from 30 m to 5.845 km with an average length of 671 m in the field. The total length of the mapped lineaments is approximately 1289 km. The most important lineament (5.845 km length) diagonally crosses the study area in the direction NNE-SSW. In addition to this trend, all others are smaller than 14 km. More than 92% of lineaments are less than 5 km in size and only 1.3% of them are larger than 10 km. Small lineaments are thus the most numerous. According to their directions, the lineaments listed are grouped into 18 directional classes of 10-degree intervals. The rosette of their directions highlights the preferred directions NE-SW, N-S, E-W, NNE-SSW and ENE-WSW. Most of the lineaments clusters in the central part of the area are N20<span style="white-space:nowrap;">°</span> - 30<span style="white-space:nowrap;">°</span>E and N60<span style="white-space:nowrap;">°</span> - 70<span style="white-space:nowrap;">°</span>E trending lineaments. In this study, the NE-SW trend dominates the structural trend followed by NW-SE and N-S. This can be an indication of the directions of groundwater movement in the area. Alluvial plain and valley have moderate to very good groundwater potential that occurs all over the study area. Porosity of the volcanic rocks varies greatly, but it is everywhere more porous than the underlying, unweathered bedrock. There are essentially three classes (low, average and high) of groundwater potential zones. Hight potential zones are observed around the localities of the Khogham, Mbatpit and Mbam massifs on the one hand and Manswen, Njikwop, Mfelap, Foumban, Njindaré, Nkoundem and Ngwen jigoumbé localities on the other hand. About 13% of the area has good groundwater potential around the mountains while 58% is moderately good which corresponds to high to moderate lineament densities situated at average altitude 1200 m and about 31% of the area has poor groundwater potential corresponding to low lineament density areas. Moreover, this work has helped develop a detailed lineament map that can be used for mining and hydrological prospecting campaigns.
文摘The present work focuses on the volcanic basement rock geochemistry of Mount Makabaï(MarouaCameroon city)in relation to groundwater geochemistry.Investigations were centered on an approach involving an association of several methods such as geological cartography,hydrogeology,and geochemistry.Three rock samples,four disturbed soil samples,three undisturbed soil samples,and 20 samples of groundwater in 10 wells were collected during fieldwork and prepared for laboratory analyses.Bedrocks exhibit porphyritic,aphyric,and subaphiric textures.The phenocryst phases are mainly olivine,clinopyroxene,and plagioclase.Based on whole rock major element chemical compositions,the Makabaï samples,plotted on Na_(2)O+K_(2)O versus SiO_(2)diagram,are mugearite,hawaiite,and basalt.The ratio of(MgO+CaO)/(Na_(2)O+K_(2)O)exceeds unity and shows dominance of alkaline Earth metals(MgO:2.99-4.48%;CaO:6.19-9.80%)relatively to alkali metals(Na_(2)O:2.27-4.46%;K_(2)O:2.09-2.51%).Exchangeable base contents are high,mostly represented by Ca and Mg,whose contents vary from 14.6 to 35.28 cmol(+)kg^(-1)and from 3.28 to9.48 cmol(+)kg^(-1)respectively.The CECclayis likewise high,fluctuating between 116.80 and181.38 cmol(+)kg^(-1),values in line with the presence of 2:1 clay minerals represented in the study area by montmorillonite.In the water samples,the Ca2+and Na+contents are generally higher than K^(+)and Mg^(2+),reflecting the relative abundance of Na_(2)O and CaO oxides to K_(2)O and MgO oxides in rocks where different waters were sampled.The waters of Makabaï are acidic to neutral(6.3≤pH≤7.4)and weakly to highly mineralized(110.0≤EC≤1190.0μS/cm).Hydro-geochemical classification by using the Piper diagram revealed two water types:(1)CaMg-HCO_(3)(40%)and(2)CaMg-Cl or CaMg-SO4(60%).The average content of ions in all the analyzed samples was HCO_(3)^(-)>>NO_(3)^(-)>SO_(4)^(2-)>Cl-for anions and Ca^(2+)>>Mg^(2+)>Na^(+)>K^(+)for cations.Major mechanisms governing ionic constituents of groundwater in the study area are water-rock interactions,silicate weathering,and ion exchange.
