This study focuses on the mapping of lineaments using remote sensing techniques and Geographic Information Systems.The aim is to carry out a statistical analysis of the lineaments in order to better understand the org...This study focuses on the mapping of lineaments using remote sensing techniques and Geographic Information Systems.The aim is to carry out a statistical analysis of the lineaments in order to better understand the organization of fracturing in the Batie district,and to identify areas of high fracturing density and their relationship with the hydrographic network.The methodology implemented to achieve these objectives is based on the processing and analysis of Landsat 9 Operational Land Imager/Thermal Infrared Sensor(OLI/TIRS)satellite imagery and Shuttle Radar Topography Mission(SRTM)data covering the study area.After essential pre-processing of data,the following processing techniques were applied:Principal Component Analysis,Sobel Directional Filter with a 3×3 matrix and shaded relief of SRTM data with a sun azimuth of 345°,altitude of 45 m and an elevation factor of 3,followed by manual lineament extraction.The results reveal a total of 176 lineaments,ranging in size from 0.002 to 2.461 km,with an average length of 840.66 km.The projection of these lineaments on a Rose diagram shows a predominance of the North East–South-West(NE-SW)direction,which is the direction of the major tectonic fractures that affect the basement of Central Africa.These lineaments are organized into networks and corridors that define large fracture zones or corridors that control the drainage of the study area.The zones with networks show medium and high densities.This fracturing density gives good aquifer and reservoir potential to the study area.展开更多
Neotectonic activity can be deduced from stream network patterns and as an outcome of its evolution. The objective of this study is to investigate the use of the stream network morphology and morphometric methods to a...Neotectonic activity can be deduced from stream network patterns and as an outcome of its evolution. The objective of this study is to investigate the use of the stream network morphology and morphometric methods to assess neotectonic signatures in Nefza region situated in North-West of Tunisia. For this aim, a Digital Elevation Model (DEM), hydrographic layers extracted from Nefza topographic map (1/25,000), lithology and tectonic lineament parameters extracted from the geologic map (1/50,000) were used. The objective of this paper is to map structural and lithological discontinuities of the study area, by the morphostructural analysis of the topography extracted of DEM as well as the drainage anomalies. This work allowed the characterization of discontinuities of lithologic and structural origin. The previously conducted studies in the study area, confirm that is crossed by lineaments at several directions E-W, N-S, NE-SW and NW-SE. Based on the results obtained from this study regarding the correlation between tectonic and hydrographic network, we can highlight a regional rejuvenation tendency of the most mapped lineaments.展开更多
The combination of structural and lithological data with morphometric indicators in a GIS environment constitutes a methodological approach with high added value to identify neotectonic deformations, in particular in ...The combination of structural and lithological data with morphometric indicators in a GIS environment constitutes a methodological approach with high added value to identify neotectonic deformations, in particular in the Quaternary outcrops where faults are generally masked by thick recent sediments. This approach, based on the crossing of multisource data, is used in this work to understand the mechanisms that generate landscape forms in the Quaternary outcrop of Oued Lahmar, which belongs to the northwest of Tunisia. In fact, the databases of various morphometric indicators, extracted from the hydrographic network, have been generated using remote sensing data and open sources applications. This database has been enriched by lithological and tectonic data extracted from the regional geological map, to understand the results of the morphometric analysis. The results obtained provide valuable information on the identification of subsurface activity in Oued Lahmar and large vicinity areas with heterogeneous geomorphic and structural characteristics. Indeed, this study revealed the existence of an E-W subsurface tectonic control covered by the Quaternary sedimentary series not indicated on the geological map of the region. This tectonic direction, which follows most of the magmatic outcrop edge in the region, may allow the intrusion of magma and the rejuvenation of ancient deep faults.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
文摘This study focuses on the mapping of lineaments using remote sensing techniques and Geographic Information Systems.The aim is to carry out a statistical analysis of the lineaments in order to better understand the organization of fracturing in the Batie district,and to identify areas of high fracturing density and their relationship with the hydrographic network.The methodology implemented to achieve these objectives is based on the processing and analysis of Landsat 9 Operational Land Imager/Thermal Infrared Sensor(OLI/TIRS)satellite imagery and Shuttle Radar Topography Mission(SRTM)data covering the study area.After essential pre-processing of data,the following processing techniques were applied:Principal Component Analysis,Sobel Directional Filter with a 3×3 matrix and shaded relief of SRTM data with a sun azimuth of 345°,altitude of 45 m and an elevation factor of 3,followed by manual lineament extraction.The results reveal a total of 176 lineaments,ranging in size from 0.002 to 2.461 km,with an average length of 840.66 km.The projection of these lineaments on a Rose diagram shows a predominance of the North East–South-West(NE-SW)direction,which is the direction of the major tectonic fractures that affect the basement of Central Africa.These lineaments are organized into networks and corridors that define large fracture zones or corridors that control the drainage of the study area.The zones with networks show medium and high densities.This fracturing density gives good aquifer and reservoir potential to the study area.
文摘Neotectonic activity can be deduced from stream network patterns and as an outcome of its evolution. The objective of this study is to investigate the use of the stream network morphology and morphometric methods to assess neotectonic signatures in Nefza region situated in North-West of Tunisia. For this aim, a Digital Elevation Model (DEM), hydrographic layers extracted from Nefza topographic map (1/25,000), lithology and tectonic lineament parameters extracted from the geologic map (1/50,000) were used. The objective of this paper is to map structural and lithological discontinuities of the study area, by the morphostructural analysis of the topography extracted of DEM as well as the drainage anomalies. This work allowed the characterization of discontinuities of lithologic and structural origin. The previously conducted studies in the study area, confirm that is crossed by lineaments at several directions E-W, N-S, NE-SW and NW-SE. Based on the results obtained from this study regarding the correlation between tectonic and hydrographic network, we can highlight a regional rejuvenation tendency of the most mapped lineaments.
文摘The combination of structural and lithological data with morphometric indicators in a GIS environment constitutes a methodological approach with high added value to identify neotectonic deformations, in particular in the Quaternary outcrops where faults are generally masked by thick recent sediments. This approach, based on the crossing of multisource data, is used in this work to understand the mechanisms that generate landscape forms in the Quaternary outcrop of Oued Lahmar, which belongs to the northwest of Tunisia. In fact, the databases of various morphometric indicators, extracted from the hydrographic network, have been generated using remote sensing data and open sources applications. This database has been enriched by lithological and tectonic data extracted from the regional geological map, to understand the results of the morphometric analysis. The results obtained provide valuable information on the identification of subsurface activity in Oued Lahmar and large vicinity areas with heterogeneous geomorphic and structural characteristics. Indeed, this study revealed the existence of an E-W subsurface tectonic control covered by the Quaternary sedimentary series not indicated on the geological map of the region. This tectonic direction, which follows most of the magmatic outcrop edge in the region, may allow the intrusion of magma and the rejuvenation of ancient deep faults.
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.
