Dams are designed for water storage intended to compensate downstream fluctuations that are stabilizing water supply and hydropower production.Hydraulic modelling tools and schemes allow understanding the hydraulic ch...Dams are designed for water storage intended to compensate downstream fluctuations that are stabilizing water supply and hydropower production.Hydraulic modelling tools and schemes allow understanding the hydraulic characteristics of the irrigation systems and mitigating uncertainty inherent to dam removals.The construction of the Niandouba dam at the confluence of the Kayanga and Anambérivers(Senegal)has perturbed the natural flow of the AnambéRiver to feed the Waïma Lake and irrigated perimeters.The flow gauges at the Kayanga and AnambéRivers are no longer operational.In this study,the HEC-RAS(Hydrological Engineering Centre River Analysis System)and the RAS Mapper is used to simulate the flow propagation of the Kayanga-Anambéhydraulic system ranging from the Niandouba dam to the entry of Waïma lake.The HEC-RAS modelling enables the estimating of,among other variables,water levels,depths and flow velocities for the different flow configurations and different cross-sectional zones.This study presents a flood mapping of the Kayanga-Anambéhydro system using the RAS Mapper and HEC-RAS hydraulic modelling tools.The study has exhibited the depths at the inlet of the supply channels where the pumping stations are located.展开更多
The Confluent and Niandouba dams were built in 1984 and 1997 respectively to better control water resources, increase agricultural production and promote local development. This article studies their evolution on the ...The Confluent and Niandouba dams were built in 1984 and 1997 respectively to better control water resources, increase agricultural production and promote local development. This article studies their evolution on the Kayanga/Geba River, a transboundary river between Guinea, Senegal and Guinea-Bissau, from its impoundment to the present day. The topographic characteristics analysed through the DTMs (Digital Terrain Models) show a flat shape for the Confluent Dam Lake and long plateaus for the Niandouba Dam Lake. The cross-sections present a variety of morphologies ranging from wide U-shaped valleys with sinuous bottoms to deep V-shaped valleys. The homogenisation and reconstruction of missing values were carried out using the regional vector me<span>thod. The application of Pettitt’s statistical test on annual rainfall (1932-2019) indicates breaks of stationarity in 1967 or 1969. The post-breakage deficits range from 11.4% to 19.4%. The segmentation method corroborates the results of the Pettitt test. The variations of the surface area of the Confluent and Niandouba water bodies are linked to rainfall, evaporation and withdrawals for different uses. Their monitoring would allow for better management of ava</span>ilable water resources but also for good planning of off-season crops.展开更多
文摘Dams are designed for water storage intended to compensate downstream fluctuations that are stabilizing water supply and hydropower production.Hydraulic modelling tools and schemes allow understanding the hydraulic characteristics of the irrigation systems and mitigating uncertainty inherent to dam removals.The construction of the Niandouba dam at the confluence of the Kayanga and Anambérivers(Senegal)has perturbed the natural flow of the AnambéRiver to feed the Waïma Lake and irrigated perimeters.The flow gauges at the Kayanga and AnambéRivers are no longer operational.In this study,the HEC-RAS(Hydrological Engineering Centre River Analysis System)and the RAS Mapper is used to simulate the flow propagation of the Kayanga-Anambéhydraulic system ranging from the Niandouba dam to the entry of Waïma lake.The HEC-RAS modelling enables the estimating of,among other variables,water levels,depths and flow velocities for the different flow configurations and different cross-sectional zones.This study presents a flood mapping of the Kayanga-Anambéhydro system using the RAS Mapper and HEC-RAS hydraulic modelling tools.The study has exhibited the depths at the inlet of the supply channels where the pumping stations are located.
文摘The Confluent and Niandouba dams were built in 1984 and 1997 respectively to better control water resources, increase agricultural production and promote local development. This article studies their evolution on the Kayanga/Geba River, a transboundary river between Guinea, Senegal and Guinea-Bissau, from its impoundment to the present day. The topographic characteristics analysed through the DTMs (Digital Terrain Models) show a flat shape for the Confluent Dam Lake and long plateaus for the Niandouba Dam Lake. The cross-sections present a variety of morphologies ranging from wide U-shaped valleys with sinuous bottoms to deep V-shaped valleys. The homogenisation and reconstruction of missing values were carried out using the regional vector me<span>thod. The application of Pettitt’s statistical test on annual rainfall (1932-2019) indicates breaks of stationarity in 1967 or 1969. The post-breakage deficits range from 11.4% to 19.4%. The segmentation method corroborates the results of the Pettitt test. The variations of the surface area of the Confluent and Niandouba water bodies are linked to rainfall, evaporation and withdrawals for different uses. Their monitoring would allow for better management of ava</span>ilable water resources but also for good planning of off-season crops.
