The Makiso municipality is located in an urban area influenced by a very high rate of land occupation by houses. This land use has an impact on the quality of the groundwater exploited by wells and springs. This groun...The Makiso municipality is located in an urban area influenced by a very high rate of land occupation by houses. This land use has an impact on the quality of the groundwater exploited by wells and springs. This groundwater helps to make up for the deficit caused by the lack of a water distribution network. It is also threatened by pollution from human activities. In order to protect the groundwater in Makiso municipality from pollution, the study of the intrinsic vulnerability assessment in the aquifers was carried out by applying the DRASTIC method and the Geographic Information System (GIS). The results obtained using this method were grouped into two degrees of vulnerability (medium and high), with variations in DRASTIC indices of [141 - 145] for the medium degree and [146 - 175] for the high degree. The high vulnerability class is the most dominant, with a percentage of 96.5% of the study area. The medium vulnerability class, which represents 3.5% of the area of the Makiso municipality, is mainly located in the western (medical plateau district), central (Lualaba district) and southern (commercial district) sectors in the form of isolated pockets. A comparison of the nitrate distribution map with the final vulnerability map shows that the areas defined as highly vulnerable by the DRASTIC method and the areas with high nitrate concentrations (above 0.11 mg/l) are in agreement. On the other hand, there are other areas with low nitrate concentrations (below 0.05 mg/l) which correspond to the high vulnerability indices.展开更多
This work presents a study of the Paleogene sandstones of the Manika plateau in Kolwezi, DR Congo. These sandstones belong to the “Grès polymorphes” group, which together with the overlying “Sables ocre” make...This work presents a study of the Paleogene sandstones of the Manika plateau in Kolwezi, DR Congo. These sandstones belong to the “Grès polymorphes” group, which together with the overlying “Sables ocre” makes up the Kalahari Supergroup. Sedimentological and geochemical analyses have enabled us to characterize these sandstones and determine their origin, the conditions of their formation and the tectonic context in which they were developed. The results show that the sandstones are quartz arenites with a high level of mineralogical, textural and chemical maturity. They are recycled sandstones, formed in an intracratonic sedimentary basin, in the context of a passive continental margin, after a long fluvial transport of sediments. These sandstones initially come from intense alteration of magmatic rocks with felsic composition, mainly tonalite-trondhjemite-granodiorite (TTG) complexes, in hot, humid palaeoclimatic conditions and oxidizing environments.展开更多
Environmental change is characterized as an alteration in the environment caused primarily by human activities and ecological processes that are natural. Given the fact that the southern part of the province of Haut-K...Environmental change is characterized as an alteration in the environment caused primarily by human activities and ecological processes that are natural. Given the fact that the southern part of the province of Haut-Katanga in the Democratic Republic of the Congo (DRC) is part of the African Copperbelt and has been a region of intense mining for decades, humans have affected the physical environment in various ways: such as overpopulation, suburbanization, wastage, deforestation. It is therefore important to track and control the changes in the area’s mining activities. This study aimed to analyze these changes using remote sensing techniques. Landsat satellite images from 2002 and 2022 were processed and classified to quantify changes in built-up area, agricultural land, and vegetation cover over the 20-year period. The classification results revealed sizable differences between the two time points, indicating considerable expansion of built-up land and declines in agricultural land and vegetation cover from 2002 to 2022 in Likasi. These findings provide evidence that urban growth has transformed the landscape in Likasi, likely at the expense of farmland and ecosystems. Further analysis of the remote sensing data could quantify the changes and model future trends to support sustainable land use planning. The land cover and land use analysis were performed with the assistance of the ERDAS 16.6.13 software by mapping LANDSAT data from two different years 2002 and 2022.展开更多
The analysis and quantification of hydro-morphometric characteristics are essential for better management of water resources and more effective planning of hydroelectric projects in the Tshopo basin.Unfortunately,few ...The analysis and quantification of hydro-morphometric characteristics are essential for better management of water resources and more effective planning of hydroelectric projects in the Tshopo basin.Unfortunately,few studies have been carried out to assess these characteristics at the scale of this basin.Our methodological approach consists of using Geographic Information System(GIS)software analysis tools applied to the Digital Elevation Model(DEM)derived from the Advanced Land Observing Satellite(ALOS)World 3D-30m image.This enabled us to automatically extract the hydrographic network and generate the Tshopo sub-watersheds.The results of this analysis show that the Tshopo catchment area is of the order of magnitude 7.A total of 8 sub-watersheds were identified,covering an area of around 19,335 km2.They are elongated in shape,with a coefficient of compactness(KG)of between 1.84 and 2.52.Average slopes are low,ranging from 0.84%to 3.58%.Run-off velocity is generally low,with a velocity range(Ve)of 2.3 to 4.79 km/h.The duration of run-off concentration(Tc)varies between 30.2 and 70.2 h in the tributaries of the Tshopo.The hydrographic network is dense,with drainage densities(Dd)ranging from 0.91 to 1.72 km/km2.The watercourses form a homogeneous dendritic network,but with local variations.In some places,the network can take on a parallel or rectangular shape.展开更多
The most characteristic hydro-morphometric parameters controlling water flow in the Tshopo catchment have not yet been determined.Correlation analysis,multiple linear regression and hierarchical ascending classificati...The most characteristic hydro-morphometric parameters controlling water flow in the Tshopo catchment have not yet been determined.Correlation analysis,multiple linear regression and hierarchical ascending classification were applied to all the data in order to identify the most characteristic variables that significantly influence water flow velocity,and to group together physically similar sub-catchments.The results highlight the importance of topography on water flow.Three topographical variables,namely median altitude(H50),overall gradient(Dg)and specific gradient(Ds),have a significant influence(p-value≤0.05)on surface water flow velocity(Ve)in the Tshopo sub-catchments.Two opposing groups(G1 and G2)of sub-catchments were identified,on the one hand the sub-catchments belonging to the upper and middle course of the Tshopo(SBV1,SBV2,SBV3 and SBV5)and on the other the sub-catchments of the lower course(SBV6,SBV7 and SBV8).The first group is characterized by moderate relief(Ds ranging from 53.19 to 73.6 m),while the second group has low relief(Ds ranging from 18.1 to 29.43 m).展开更多
文摘The Makiso municipality is located in an urban area influenced by a very high rate of land occupation by houses. This land use has an impact on the quality of the groundwater exploited by wells and springs. This groundwater helps to make up for the deficit caused by the lack of a water distribution network. It is also threatened by pollution from human activities. In order to protect the groundwater in Makiso municipality from pollution, the study of the intrinsic vulnerability assessment in the aquifers was carried out by applying the DRASTIC method and the Geographic Information System (GIS). The results obtained using this method were grouped into two degrees of vulnerability (medium and high), with variations in DRASTIC indices of [141 - 145] for the medium degree and [146 - 175] for the high degree. The high vulnerability class is the most dominant, with a percentage of 96.5% of the study area. The medium vulnerability class, which represents 3.5% of the area of the Makiso municipality, is mainly located in the western (medical plateau district), central (Lualaba district) and southern (commercial district) sectors in the form of isolated pockets. A comparison of the nitrate distribution map with the final vulnerability map shows that the areas defined as highly vulnerable by the DRASTIC method and the areas with high nitrate concentrations (above 0.11 mg/l) are in agreement. On the other hand, there are other areas with low nitrate concentrations (below 0.05 mg/l) which correspond to the high vulnerability indices.
文摘This work presents a study of the Paleogene sandstones of the Manika plateau in Kolwezi, DR Congo. These sandstones belong to the “Grès polymorphes” group, which together with the overlying “Sables ocre” makes up the Kalahari Supergroup. Sedimentological and geochemical analyses have enabled us to characterize these sandstones and determine their origin, the conditions of their formation and the tectonic context in which they were developed. The results show that the sandstones are quartz arenites with a high level of mineralogical, textural and chemical maturity. They are recycled sandstones, formed in an intracratonic sedimentary basin, in the context of a passive continental margin, after a long fluvial transport of sediments. These sandstones initially come from intense alteration of magmatic rocks with felsic composition, mainly tonalite-trondhjemite-granodiorite (TTG) complexes, in hot, humid palaeoclimatic conditions and oxidizing environments.
文摘Environmental change is characterized as an alteration in the environment caused primarily by human activities and ecological processes that are natural. Given the fact that the southern part of the province of Haut-Katanga in the Democratic Republic of the Congo (DRC) is part of the African Copperbelt and has been a region of intense mining for decades, humans have affected the physical environment in various ways: such as overpopulation, suburbanization, wastage, deforestation. It is therefore important to track and control the changes in the area’s mining activities. This study aimed to analyze these changes using remote sensing techniques. Landsat satellite images from 2002 and 2022 were processed and classified to quantify changes in built-up area, agricultural land, and vegetation cover over the 20-year period. The classification results revealed sizable differences between the two time points, indicating considerable expansion of built-up land and declines in agricultural land and vegetation cover from 2002 to 2022 in Likasi. These findings provide evidence that urban growth has transformed the landscape in Likasi, likely at the expense of farmland and ecosystems. Further analysis of the remote sensing data could quantify the changes and model future trends to support sustainable land use planning. The land cover and land use analysis were performed with the assistance of the ERDAS 16.6.13 software by mapping LANDSAT data from two different years 2002 and 2022.
文摘The analysis and quantification of hydro-morphometric characteristics are essential for better management of water resources and more effective planning of hydroelectric projects in the Tshopo basin.Unfortunately,few studies have been carried out to assess these characteristics at the scale of this basin.Our methodological approach consists of using Geographic Information System(GIS)software analysis tools applied to the Digital Elevation Model(DEM)derived from the Advanced Land Observing Satellite(ALOS)World 3D-30m image.This enabled us to automatically extract the hydrographic network and generate the Tshopo sub-watersheds.The results of this analysis show that the Tshopo catchment area is of the order of magnitude 7.A total of 8 sub-watersheds were identified,covering an area of around 19,335 km2.They are elongated in shape,with a coefficient of compactness(KG)of between 1.84 and 2.52.Average slopes are low,ranging from 0.84%to 3.58%.Run-off velocity is generally low,with a velocity range(Ve)of 2.3 to 4.79 km/h.The duration of run-off concentration(Tc)varies between 30.2 and 70.2 h in the tributaries of the Tshopo.The hydrographic network is dense,with drainage densities(Dd)ranging from 0.91 to 1.72 km/km2.The watercourses form a homogeneous dendritic network,but with local variations.In some places,the network can take on a parallel or rectangular shape.
文摘The most characteristic hydro-morphometric parameters controlling water flow in the Tshopo catchment have not yet been determined.Correlation analysis,multiple linear regression and hierarchical ascending classification were applied to all the data in order to identify the most characteristic variables that significantly influence water flow velocity,and to group together physically similar sub-catchments.The results highlight the importance of topography on water flow.Three topographical variables,namely median altitude(H50),overall gradient(Dg)and specific gradient(Ds),have a significant influence(p-value≤0.05)on surface water flow velocity(Ve)in the Tshopo sub-catchments.Two opposing groups(G1 and G2)of sub-catchments were identified,on the one hand the sub-catchments belonging to the upper and middle course of the Tshopo(SBV1,SBV2,SBV3 and SBV5)and on the other the sub-catchments of the lower course(SBV6,SBV7 and SBV8).The first group is characterized by moderate relief(Ds ranging from 53.19 to 73.6 m),while the second group has low relief(Ds ranging from 18.1 to 29.43 m).
