In watershed hydrology,the morphometric features of a river basin are vital to examine the lower Orashi River basin morphological and hydrological aspects,as well as its flood potential,based on their morphometric cha...In watershed hydrology,the morphometric features of a river basin are vital to examine the lower Orashi River basin morphological and hydrological aspects,as well as its flood potential,based on their morphometric characteristics using remotely sensed SRTM data that was analyzed with ArcGIS software.The areal,linear,and relief aspects of the Orashi River basin were examined as morphometric parameters.The lower Orashi river basin,according to the findings,has a total size of 625.61 km2 and a perimeter of 307.98 km,with a 5th order river network based on Strahler categorization and a dendritic drainage pattern.Because of low drainage density,the drainage texture is very fine,the relief is low,and the slope is very low.Bifurcation ratio,circularity ratio,drainage density aspect ratio,form factor,and stream frequency values indicate that the basin is less elongated and would produce surface runoff for a longer period,while topographic changes show that the river is decreasing with depth in the land area at about the same elevation as a result of sand deposited due to lack of maintenance by dredging,which implies that the basin is morphometrically elevated and sensitive to erosion and flooding.To understand geo-hydrological features and to plan and manage watersheds,morphometric analysis based on geographic information systems and remote sensing techniques is beneficial.展开更多
This study addresses the pressing need to assess foundation bearing capacity in Opolo,Yenagoa,Bayelsa State,Nigeria.The significance lies in the dearth of comprehensive geotechnical data for construction planning in t...This study addresses the pressing need to assess foundation bearing capacity in Opolo,Yenagoa,Bayelsa State,Nigeria.The significance lies in the dearth of comprehensive geotechnical data for construction planning in the region.Past research is limited and this study contributes valuable insights by integrating Geographic Information System(GIS)with the Generalized Reciprocal Method(GRM).To collect data,near-surface seismic refraction surveys were conducted along three designated lines,utilizing ABEM Terraloc Mark 6 equipment,Easy Refract,and ArcGIS 10.4.1 software.This methodology allowed for the determination of key geotechnical parameters essential for soil characterization at potential foundation sites.The results revealed three distinct geoseismic layers.The uppermost layer,within a depth of 0.89 to 1.50 meters,exhibited inadequate compressional and shear wave velocities and low values for oedometric modulus,shear modulus,N-value,ultimate bearing capacity,and allowable bearing capacity.This indicates the presence of unsuitable,soft,and weak alluvial deposits for substantial structural loads.In contrast,the second layer(1.52 to 3.84 m depth)displayed favorable geotechnical parameters,making it suitable for various construction loads.The third layer(15.00 to 26.05 m depth)exhibited varying characteristics.The GIS analysis highlighted the unsuitability of the uppermost layer for construction,while the second and third layers were found to be fairly competent and suitable for shallow footing and foundation design.In summary,this study highlights the importance of geotechnical surveys in Opolo’s construction planning.It offers vital information for informed choices,addresses issues in the initial layer,and suggests secure,sustainable construction options.展开更多
文摘In watershed hydrology,the morphometric features of a river basin are vital to examine the lower Orashi River basin morphological and hydrological aspects,as well as its flood potential,based on their morphometric characteristics using remotely sensed SRTM data that was analyzed with ArcGIS software.The areal,linear,and relief aspects of the Orashi River basin were examined as morphometric parameters.The lower Orashi river basin,according to the findings,has a total size of 625.61 km2 and a perimeter of 307.98 km,with a 5th order river network based on Strahler categorization and a dendritic drainage pattern.Because of low drainage density,the drainage texture is very fine,the relief is low,and the slope is very low.Bifurcation ratio,circularity ratio,drainage density aspect ratio,form factor,and stream frequency values indicate that the basin is less elongated and would produce surface runoff for a longer period,while topographic changes show that the river is decreasing with depth in the land area at about the same elevation as a result of sand deposited due to lack of maintenance by dredging,which implies that the basin is morphometrically elevated and sensitive to erosion and flooding.To understand geo-hydrological features and to plan and manage watersheds,morphometric analysis based on geographic information systems and remote sensing techniques is beneficial.
文摘This study addresses the pressing need to assess foundation bearing capacity in Opolo,Yenagoa,Bayelsa State,Nigeria.The significance lies in the dearth of comprehensive geotechnical data for construction planning in the region.Past research is limited and this study contributes valuable insights by integrating Geographic Information System(GIS)with the Generalized Reciprocal Method(GRM).To collect data,near-surface seismic refraction surveys were conducted along three designated lines,utilizing ABEM Terraloc Mark 6 equipment,Easy Refract,and ArcGIS 10.4.1 software.This methodology allowed for the determination of key geotechnical parameters essential for soil characterization at potential foundation sites.The results revealed three distinct geoseismic layers.The uppermost layer,within a depth of 0.89 to 1.50 meters,exhibited inadequate compressional and shear wave velocities and low values for oedometric modulus,shear modulus,N-value,ultimate bearing capacity,and allowable bearing capacity.This indicates the presence of unsuitable,soft,and weak alluvial deposits for substantial structural loads.In contrast,the second layer(1.52 to 3.84 m depth)displayed favorable geotechnical parameters,making it suitable for various construction loads.The third layer(15.00 to 26.05 m depth)exhibited varying characteristics.The GIS analysis highlighted the unsuitability of the uppermost layer for construction,while the second and third layers were found to be fairly competent and suitable for shallow footing and foundation design.In summary,this study highlights the importance of geotechnical surveys in Opolo’s construction planning.It offers vital information for informed choices,addresses issues in the initial layer,and suggests secure,sustainable construction options.
