The Shannon River Basin (SRB) is the largest in Ireland at more than 18,000 km2 in area and is th... more The Shannon River Basin (SRB) is the largest in Ireland at more than 18,000 km2 in area and is the main source of water for drinking, agriculture, ecology, industry, etc. for the surrounding area which includes a large number of towns and the city of Limerick. Therefore it is essential to ensure that such demands can be met particularly during dry seasons when the rainfall ceases and the groundwater and water stored in lakes are important to maintain baseflows. Since these dry seasons are likely to occur more frequently in the future as a result of climate change, the vulnerability of water supplies in the SRB must be assessed. A frequency analysis of different low flow events is a powerful tool for this purpose and has been applied in this study to assess low flow conditions in the SRB. Flow data for 55 gauges in the SRB has been analysed and various series of annual low flow indicators extracted. These include: (1) the annual minimum; (2) 3-day sustained low flow (3-SLF); (3) 7-da...
Wastewater arising from the Coachford agglomeration is treated at the existing Coachford Waste Wa... more Wastewater arising from the Coachford agglomeration is treated at the existing Coachford Waste Water Treatment Plant (WWTP). This wastewater treatment facility has a primary treatment only with a design capacity of 450 population equivalent (PE) and it discharges the effluent into the Inniscarra Reservoir. The discharge from Coachford WWTP has been identified by the Lower Lee Owenboy Water Management Unit Action Plan (WMUAP) as a point source pressure on the waters of the Lower Lee Owenboy catchment and also as a cause of the strongly eutrophic status of Inniscarra Reservoir water quality by the EPA in 2009. Therefore, new emission limit values (ELVs) for the main water quality parameters in the effluent from Coachford WWTP have been proposed by the EPA to ensure compliance with the relevant water quality standards downstream of effluent discharging point. For lakes, the most important water parameters are phosphorus and nitrogen and the relevant environmental quality standards defi...
Floods remain to be one of the natural catastrophic disasters with serious adverse social and eco... more Floods remain to be one of the natural catastrophic disasters with serious adverse social and economic implications on individuals and communities all around the world. In Ireland, frequency of flood events have increased dramatically during the last forty years and is expected to continue to rise primarily due to changes in rainfall and temperature patterns as a result of the global climate change. Small river catchments are usually vulnerable to different types of flooding particularly those associated with “monster” rainfall events, which are characterised by short durations and high intensities. Therefore accurate prediction of flood hydrographs resulting from these rainfall events are vital for issuing timely and detailed warning to competent authorities in order to allow for efficient preparedness in the affected catchment and other downstream areas. The current study assess the performance of Unit Hydrograph model in predicting flood hydrograph due to extreme rainfall storms ...
Presented at the 7th International Water Association Symposium on Systems Analysis and Integrated... more Presented at the 7th International Water Association Symposium on Systems Analysis and Integrated Assessment in Water Management, Washington, D.C., 7-9 May 2007
Phosphorus transported from agriculture land has been identified as a major source of water pollu... more Phosphorus transported from agriculture land has been identified as a major source of water pollution in a large number of Irish catchments. Models of this process are required in order to design and assess management measures. This paper reports on the comparison and assessment of two of the most promising physically-based distributed models, SWAT and HSPF, with particular emphasis on their suitability for Irish conditions. The representation of the overall soil phosphorus cycle is similar in both models but there is a significant difference in the level of detail in describing the chemical and biochemical processes in each model. Also there are differences in modeling the mechanisms by which phosphorus is removed from the soil column and either transported in dissolved form with the runoff water or in particulate form attached to eroded or detached sediment. These differences could have a significant influence on performance when using either of the models to simulate phosphorus l...
Abstract: The current challenge in the implementation of the Water Framework Directive in Ireland... more Abstract: The current challenge in the implementation of the Water Framework Directive in Ireland is to introduce programmes of measures that will address the targeted environmental objectives in each River Basin District (RBD). Introduction of such programmes requires ...
Water science and technology : a journal of the International Association on Water Pollution Research, 2005
Grid-oriented, physically based catchment models calculate fields of various hydrological variabl... more Grid-oriented, physically based catchment models calculate fields of various hydrological variables relevant to phosphorus detachment and transport. These include (i) for surface transport: overland flow depth and flow in the coordinate directions, sediment load, and sediment concentration and (ii) for subsurface transport: soil moisture and hydraulic head at various depths in the soil. These variables can be considered as decoupled from any chemical phosphorus model since phosphorus concentrations, either as dissolved or particulate, do not influence the model calculations of the hydrological fields. Thus the phosphorus concentration calculations can be carried out independently from and after the hydrological calculations. This makes it possible to produce a separate phosphorus modelling component which takes as input the hydrological fields produced by the catchment model and which calculates, at each simulation time step, the phosphorus concentrations in the flows. This paper su...
The Shannon River Basin (SRB) is the largest in Ireland at more than 18,000 km2 in area and is th... more The Shannon River Basin (SRB) is the largest in Ireland at more than 18,000 km2 in area and is the main source of water for drinking, agriculture, ecology, industry, etc. for the surrounding area which includes a large number of towns and the city of Limerick. Therefore it is essential to ensure that such demands can be met particularly during dry seasons when the rainfall ceases and the groundwater and water stored in lakes are important to maintain baseflows. Since these dry seasons are likely to occur more frequently in the future as a result of climate change, the vulnerability of water supplies in the SRB must be assessed. A frequency analysis of different low flow events is a powerful tool for this purpose and has been applied in this study to assess low flow conditions in the SRB. Flow data for 55 gauges in the SRB has been analysed and various series of annual low flow indicators extracted. These include: (1) the annual minimum; (2) 3-day sustained low flow (3-SLF); (3) 7-da...
Wastewater arising from the Coachford agglomeration is treated at the existing Coachford Waste Wa... more Wastewater arising from the Coachford agglomeration is treated at the existing Coachford Waste Water Treatment Plant (WWTP). This wastewater treatment facility has a primary treatment only with a design capacity of 450 population equivalent (PE) and it discharges the effluent into the Inniscarra Reservoir. The discharge from Coachford WWTP has been identified by the Lower Lee Owenboy Water Management Unit Action Plan (WMUAP) as a point source pressure on the waters of the Lower Lee Owenboy catchment and also as a cause of the strongly eutrophic status of Inniscarra Reservoir water quality by the EPA in 2009. Therefore, new emission limit values (ELVs) for the main water quality parameters in the effluent from Coachford WWTP have been proposed by the EPA to ensure compliance with the relevant water quality standards downstream of effluent discharging point. For lakes, the most important water parameters are phosphorus and nitrogen and the relevant environmental quality standards defi...
Floods remain to be one of the natural catastrophic disasters with serious adverse social and eco... more Floods remain to be one of the natural catastrophic disasters with serious adverse social and economic implications on individuals and communities all around the world. In Ireland, frequency of flood events have increased dramatically during the last forty years and is expected to continue to rise primarily due to changes in rainfall and temperature patterns as a result of the global climate change. Small river catchments are usually vulnerable to different types of flooding particularly those associated with “monster” rainfall events, which are characterised by short durations and high intensities. Therefore accurate prediction of flood hydrographs resulting from these rainfall events are vital for issuing timely and detailed warning to competent authorities in order to allow for efficient preparedness in the affected catchment and other downstream areas. The current study assess the performance of Unit Hydrograph model in predicting flood hydrograph due to extreme rainfall storms ...
Presented at the 7th International Water Association Symposium on Systems Analysis and Integrated... more Presented at the 7th International Water Association Symposium on Systems Analysis and Integrated Assessment in Water Management, Washington, D.C., 7-9 May 2007
Phosphorus transported from agriculture land has been identified as a major source of water pollu... more Phosphorus transported from agriculture land has been identified as a major source of water pollution in a large number of Irish catchments. Models of this process are required in order to design and assess management measures. This paper reports on the comparison and assessment of two of the most promising physically-based distributed models, SWAT and HSPF, with particular emphasis on their suitability for Irish conditions. The representation of the overall soil phosphorus cycle is similar in both models but there is a significant difference in the level of detail in describing the chemical and biochemical processes in each model. Also there are differences in modeling the mechanisms by which phosphorus is removed from the soil column and either transported in dissolved form with the runoff water or in particulate form attached to eroded or detached sediment. These differences could have a significant influence on performance when using either of the models to simulate phosphorus l...
Abstract: The current challenge in the implementation of the Water Framework Directive in Ireland... more Abstract: The current challenge in the implementation of the Water Framework Directive in Ireland is to introduce programmes of measures that will address the targeted environmental objectives in each River Basin District (RBD). Introduction of such programmes requires ...
Water science and technology : a journal of the International Association on Water Pollution Research, 2005
Grid-oriented, physically based catchment models calculate fields of various hydrological variabl... more Grid-oriented, physically based catchment models calculate fields of various hydrological variables relevant to phosphorus detachment and transport. These include (i) for surface transport: overland flow depth and flow in the coordinate directions, sediment load, and sediment concentration and (ii) for subsurface transport: soil moisture and hydraulic head at various depths in the soil. These variables can be considered as decoupled from any chemical phosphorus model since phosphorus concentrations, either as dissolved or particulate, do not influence the model calculations of the hydrological fields. Thus the phosphorus concentration calculations can be carried out independently from and after the hydrological calculations. This makes it possible to produce a separate phosphorus modelling component which takes as input the hydrological fields produced by the catchment model and which calculates, at each simulation time step, the phosphorus concentrations in the flows. This paper su...
Uploads
Papers by Ahmed Nasr