The hydrologic and hydraulic changings on the behavior of Mono river are the result of the stress involved by human activities, on one hand and the construction of the dam of Nangbéto and the exploitation of sand...The hydrologic and hydraulic changings on the behavior of Mono river are the result of the stress involved by human activities, on one hand and the construction of the dam of Nangbéto and the exploitation of sand in downstream of the dam by the population, between Athiémé and Agbanankin on other hand. That effect had also affected the shape of the sections of the river in the context of climate variability. It shows consequently that area is also a trapping area of sediments eroded in downstream of the dam and is responsible for the trapping of sediments in the river. The slope and the flow rate are the main factors of the real capacity of transport of a watercourse. They also determine the transport of solid flows from upstream to downstream. This drawing model established by taking into account the bathymetry of a transversal section of the Mono river at Athiémé, is the first step of a global investigation of the solid flow transport in the basin of Mono river and the boundary condition for the characterization of its hydro-sedimentary dynamics study. It aims to take into account sections and the used technique which consist to measure on one located section as the representative section of the river at Athiémé, by moving the boat used for bathymetry.展开更多
The filling of rivers generated by carried solid deposit is a factor for the raising of height of rivers and thus activates the floods and inundations. The quantification of carried solid flow charges through their ch...The filling of rivers generated by carried solid deposit is a factor for the raising of height of rivers and thus activates the floods and inundations. The quantification of carried solid flow charges through their characterization and the analysis of hydrosedimentary dynamics is the second step of the investigation of the solid flow transport in the Mono river. This study aims to quantify the volume of trapped sediments in function of the variation of the geometry of the shape of sections of the river depending of the slope and the flow rate therefore to evaluate the capacity of transport of eroded solid flows of a watercourse from upstream to downstream. Consequently, the decreasing percentage of deposited alluvium from upstream to downstream is calculated along Mono river. Thus the drawn granulometric curve of sediments and the determinate granulometric characteristics of sediments permit to quantify the carried sediment charges at each chosen section with Engelund-Hansen model in Mono river.展开更多
In recent years,water levels in some of the most heavily tapped aquifers(Upper Cretaceous)in the Beninese Mono River basin have fallen to the point where some boreholes,which used to have a permanent regime,now have a...In recent years,water levels in some of the most heavily tapped aquifers(Upper Cretaceous)in the Beninese Mono River basin have fallen to the point where some boreholes,which used to have a permanent regime,now have a temporary regime,raising questions among the population.This study attempts to answer these questions by analyzing the behavior of the Upper Cretaceous aquifer reservoir at the Athiéméoutlet,in the Benin portion of the Mono River watershed.It was based on statistical tests.To this end,the Students’t-test at 95%confidence for linear trend analysis was applied to static data collected from 5 piezometric stations around the Cretaceous aquifer recharge zone,covering the period from 2007 to 2020.Next,Pettitt break detection tests and the Bayesian method of LEE and HEGHINIAN were used to study the homogeneity of the various static levels of the aquifer’s wells and boreholes around its recharge zone on these data.The results showed that four(04)of the five(05)piezometric stations used are representative of the hydrodynamic functioning of the aquifer,with the exception of the Volly-Latadji piezometer in Aplahoué.These piezometric stations showed a significant downward trend in static levels until 2020,with a clear break in 2013.Compared with the 2007-2013 sub-period,water levels in the aquifer’s catchment structures(wells and boreholes)rose by 23%in the center of the aquifer,10%in the northeast and south,and 11%in the southwest,between 2014 and 2020.This increase in the aquifer’s water resources,which today contrasts with the realities on the ground,raises concerns about the future of the area’s groundwater resources,and calls for in-depth reflection on the part of all concerned(decision-makers,craftsmen,scientists...).展开更多
文摘The hydrologic and hydraulic changings on the behavior of Mono river are the result of the stress involved by human activities, on one hand and the construction of the dam of Nangbéto and the exploitation of sand in downstream of the dam by the population, between Athiémé and Agbanankin on other hand. That effect had also affected the shape of the sections of the river in the context of climate variability. It shows consequently that area is also a trapping area of sediments eroded in downstream of the dam and is responsible for the trapping of sediments in the river. The slope and the flow rate are the main factors of the real capacity of transport of a watercourse. They also determine the transport of solid flows from upstream to downstream. This drawing model established by taking into account the bathymetry of a transversal section of the Mono river at Athiémé, is the first step of a global investigation of the solid flow transport in the basin of Mono river and the boundary condition for the characterization of its hydro-sedimentary dynamics study. It aims to take into account sections and the used technique which consist to measure on one located section as the representative section of the river at Athiémé, by moving the boat used for bathymetry.
文摘The filling of rivers generated by carried solid deposit is a factor for the raising of height of rivers and thus activates the floods and inundations. The quantification of carried solid flow charges through their characterization and the analysis of hydrosedimentary dynamics is the second step of the investigation of the solid flow transport in the Mono river. This study aims to quantify the volume of trapped sediments in function of the variation of the geometry of the shape of sections of the river depending of the slope and the flow rate therefore to evaluate the capacity of transport of eroded solid flows of a watercourse from upstream to downstream. Consequently, the decreasing percentage of deposited alluvium from upstream to downstream is calculated along Mono river. Thus the drawn granulometric curve of sediments and the determinate granulometric characteristics of sediments permit to quantify the carried sediment charges at each chosen section with Engelund-Hansen model in Mono river.
文摘In recent years,water levels in some of the most heavily tapped aquifers(Upper Cretaceous)in the Beninese Mono River basin have fallen to the point where some boreholes,which used to have a permanent regime,now have a temporary regime,raising questions among the population.This study attempts to answer these questions by analyzing the behavior of the Upper Cretaceous aquifer reservoir at the Athiéméoutlet,in the Benin portion of the Mono River watershed.It was based on statistical tests.To this end,the Students’t-test at 95%confidence for linear trend analysis was applied to static data collected from 5 piezometric stations around the Cretaceous aquifer recharge zone,covering the period from 2007 to 2020.Next,Pettitt break detection tests and the Bayesian method of LEE and HEGHINIAN were used to study the homogeneity of the various static levels of the aquifer’s wells and boreholes around its recharge zone on these data.The results showed that four(04)of the five(05)piezometric stations used are representative of the hydrodynamic functioning of the aquifer,with the exception of the Volly-Latadji piezometer in Aplahoué.These piezometric stations showed a significant downward trend in static levels until 2020,with a clear break in 2013.Compared with the 2007-2013 sub-period,water levels in the aquifer’s catchment structures(wells and boreholes)rose by 23%in the center of the aquifer,10%in the northeast and south,and 11%in the southwest,between 2014 and 2020.This increase in the aquifer’s water resources,which today contrasts with the realities on the ground,raises concerns about the future of the area’s groundwater resources,and calls for in-depth reflection on the part of all concerned(decision-makers,craftsmen,scientists...).
