Volume:
Volume 8,
2015
Issue:
Issue 1 ,
2015,
July
Determination of The Extent of Yala River Flood Flows in The Yala Basin , Kenya
On Friday, 1st of May, 2015. 11:16:44 AM
By WANYONYI ENOCK
Topic: Flood Management
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AbstractIn Kenya, hazards caused by river floods are a common phenomenon in most parts of the country. Areas of Kano plains in Kisumu County, Budalang`i in Bu read more
In Kenya, hazards caused by river floods are a common phenomenon in most parts of the country. Areas of Kano plains in Kisumu County, Budalang`i in Busia County and Coastal areas are prone to floods. Flooding of the lower reaches of the Yala River has been occurring for a long time causing havoc in the basin. The basin has experienced loss of lives, destruction of property, outbreak of water borne diseases and siltation of arable lands that have followed flood events. In the recent past, the frequency and intensity of the floods has increased, partially attributed to climate change. The extent of Yala river flood flows, the damage they cause in the basin have not been known in order to propose proper mitigation measures. The lack of information on the flood extent has been due to difficult conditions to measure discharge in the lower Yala basin because of channel instability, high silt content and presence of weeds in the swamp. The main objective of the research was to carry out mapping of Yala river flood extent in the lower basin using Satellite imagery technique as a suitable alternative in obtaining information where traditional discharge measurement methods were not possible. The results show a change in the flood extent of about 34.2km2 from 1984 to 2010. The mapped area extent resultsmay be used for future flood management planning in the basin. The quantification of the extent of flood waters in the basin is very critical for future water resources planning and design of infrastructure such as reservoirs upstream of Yala River. This research forms anew basis for research on the extent and impacts caused by the Yala river flood flows in the basin using satellite imagery analysis technique. less
Combined Near-field and Far-field Models to predict Mixing Processes of Complex Cooling Water System
On Friday, 1st of May, 2015. 11:16:44 AM
By mohamed mohamed abdel-latif mohamed
Topic: GIS and modeling applications in river engineering
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AbstractThe aim of this paper is to improve the predictive capability of the mixing processes of complex cooling water system where several discharge sources read more
The aim of this paper is to improve the predictive capability of the mixing processes of complex cooling water system where several discharge sources may interact with large pollutant loadings in a critical layout like the Nile River. An approach to link validated near-field model predictions to hydrodynamic far-field simulations was developed. In this strategy, environmental conditions from the near-field model were used to produce boundary conditions for execution of a suite of far-field simulations. This is to allow more detailed presentation of the mixing processes. Also, it was found that one type of hydrodynamic models used to predict the mixing processes delivered highly conservative plume dilution predictions in and around the outfall site. In this study, a linking approach between the near-field model "CORMIX" and a far-field model "DELFT 3D" was employed. The results of "CORMIX" model was used as boundary conditions in the simulation process of "DELFT 3D" model. As a case study to apply this methodology, the impact of the discharge of heated effluents from diffuser outfall of the South Helwan Power Plant (planned to be built) into Nile River on the temperature distribution of the Nile water in the vicinity of the intake structures of El-kureimat Power Plant which is located 7.5 km downstream of the South Helwan Power Plant was investigated. The model results show that the thermal plume transport from the outfall of the South Helwan Power Plant will cause a temperature rise in the vicinity of the intakes of El-kureimat Power Plant of 0.7 oC in the summer time and an average rise of 1.67 oC in the winter time. Also, the produced mixing zone sizes in the vicinity of the two power plants are within the limitations stated by the aquatic environmental laws. less
Quantification of runoff components and processes using hydrochemical tracer studies in the Nyabugogo swamp, Rwanda
On Friday, 1st of May, 2015. 11:16:44 AM
By Omar Munyaneza
Topic: Other
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AbstractChemical hydrograph separations of stream discharge are commonly used to determine the fractions of old and new water contributing to the stream flow. read more
Chemical hydrograph separations of stream discharge are commonly used to determine the fractions of old and new water contributing to the stream flow. The aim of this study is to estimate the contribution of water from surface and subsurface runoffs. Furthermore other researches could compute the volume of water from the two components, which will facilitate the management of damaging floods appearing regularly in the Nyabugogo swamp area. Two rain events of 17th May and 06th June 2014 were analysed. Hydrochemical tracers such as Chloride (Cl-) and dissolved Silica (SiO2) were used to quantify the dominant runoff generation process in the Nyabugogo swamp and a hydrograph separation was conducted during two events. Results showed that the contribution of subsurface runoff is more important than the one of surface runoff, 65.3 % and 34.7 %, respectively. In urban areas like Kigali city, where Nyabugogo swamp is located, one could think that surface runoff should be more important than subsurface runoff, but this was not the case. The hydrochemical tracer concentrations revealed a relationship of river water and ground water confirming the importance of subsurface contribution to the stream flow. These results could contribute to the water resources management, infrastructure planning and design of Kigali city. less
Assessment of the Skill of Seasonal Meteorological Forecasts in the Eastern Nile
On Friday, 1st of May, 2015. 11:16:44 AM
By Doaa Amin
Topic: Enviromental aspects of river engineering
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AbstractWarnings issued several months ahead of a flood or a drought event can trigger action plans to mitigate the risks and enhance preparedness. An early w read more
Warnings issued several months ahead of a flood or a drought event can trigger action plans to mitigate the risks and enhance preparedness. An early warning system that relies upon forecasting systems can provides the necessary information. The numerical weather models give a short term weather forecast for about three days. Even with the increasing power of supercomputers, the forecast skill of numerical weather models extends to about only six days. The European Center for Medium range Weather Forecasting (ECMWF) has a dynamical seasonal forecast model gives seasonal forecasts which predict the average weather up to one year ahead. In this paper, an effort is done to skill the 51 ensembles, generated by ECMWF and enhanced by the Bias Correction Methods, using the hydrological models in Nile Forecasting System (NFS). Each ensemble is a seasonal forecast from May to November during the years (2005-2011). The results produce 51 simulated flow ensembles which are analyzed to assess the most accurate ensembles in rainfall prediction. The results show that the ensemble mean is on average better than any individual ensemble member. less
The Relationship between Turbidity and Total Suspended Solids in the Blue Nile River at Khartoum
On Friday, 1st of May, 2015. 11:16:44 AM
By Muna Musnad
Topic: Enviromental aspects of river engineering
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AbstractEstimation of sediment characteristics in the Blue Nile River is of great importance particularly for the water treatment plants in Khartoum State. It read more
Estimation of sediment characteristics in the Blue Nile River is of great importance particularly for the water treatment plants in Khartoum State. It represents a great challenge to water supply authorities due to the high variation of the sediment load through the year. It varies from 8 NTU in the recession time to more than 30000 NTU during flood season, this when coupled with the limitation of sedimentation measuring equipments makes the operation of water treatment plant (WTP) quite difficult during flood season.
Turbidity measurement with nephelometric turbidimeters is considered a good method for estimating sediment concentrations in rivers.
The relation between turbidity (T) and Total Suspended Solids (TSS) is directly proportional due to the tendency of suspended solids to attenuate or scatter light.
The main objectives of this paper are to establish a relationship between (T) and (TSS) for the Blue Nile River at Khartoum and to assess the statistical significant of this relationship. Other specific objective is to identify the degree of confidence that the relationship is close to.
The paired turbidity and TSS data used in this assessment were obtained from the central lab of Khartoum State Water Corporation (KSWC). A Regression analysis tool is used to investigate the relationships between the turbidity and TSS in order to ascertain the causal effect of one variable upon another. The correlation coefficient (R) is applied to determine the strength of the relationship. Significance of the relationship and degree of confidence are carried out by applying the statistical analysis through Hypothesis and Random Error Analysis. It is concluded that while the relationship between turbidity (T) and TSS depends on several factors, it shows strong positive linear relationship with high degree of correlation for the total, rising and falling limbs of the flood hydrograph. less
Management of Water Quality Upstream Cairo Drinking Water Plants along the Nile River
On Friday, 1st of May, 2015. 11:16:44 AM
By Reda M radey
Topic: Other
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AbstractThe population growth, economic development, with the consequent anthropogenic activities in Egypt and global climate change pose to reduce the qualit read more
The population growth, economic development, with the consequent anthropogenic activities in Egypt and global climate change pose to reduce the quality trends of surface water resources. The limited amounts of rainfall make the country dependent mainly on the Nile River. The management of river water quality is a major environmental challenge. Cairo, sits on the River Nile south of the Mediterranean Sea, just upstream of the point where the river widens into the Delta. Cairo has an average reach length along the river about 50 km (from Km 900 to km 950 Referenced to Aswan High Dam). This research study area covers Cairo governorate along the River Nile, bounded by El Saff town at Km 877.00 from the South and El Kanater town at Km 953.00 from the North. This area is of particular importance in the study of surface water quality because; industrial and municipal wastes, agricultural and run-off from developing areas were mixing with river flow and surrounding water body thereby deteriorating the water quality. This study mainly aims to develop Water Quality Management Information System (WQMIS) capable of proposing the required managent scenarios to improve water quality upstream Cairo drinking plants and control the pollution sources.
The collected data were utilized in three phases of analysis. In the first phase water quality indices (WQIs) were calculated using Canadian Water Quality Index (CWQI). In the second phase, mathematical model (MIKE11 model developed by Danish Hydraulic Institute (DHI), Denmark) was formulated to simulate a conservative WQ parameter (salinity of river water). This model was calibrated and used to simulate different scenarios to improve study reach water quality. Three WQ parameters (dissolved oxygen (DO), biochemical oxygen demand (BOD) and chemical oxygen demand (COD)) were modeled.
In the third phase, The Water Quality Management Information System (WQMIS) was constructed for assessing and predicting the situation of the WQ status under current and future conditions. The study management scenarios showed that the maximum water quality improvement can be achieved under integrated management approach of study reach water quality based on the application of drain effluent treatment, drinking water plant sludge disposal treatment and increasing the study reach flow. less
Sea water/fresh water interaction in the Red Sea coast around Port-Sudan town-Red Sea State-Eastern Sudan
On Friday, 1st of May, 2015. 11:16:44 AM
By Abdalla El Sheikh
Topic: Other
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AbstractPort-Sudan area is considered as one of the most vulnerable areas along the Red Sea coast of Sudan in terms of shortages in water supply. This study i read more
Port-Sudan area is considered as one of the most vulnerable areas along the Red Sea coast of Sudan in terms of shortages in water supply. This study is concerned with the fresh/saline water interface along the coastal area around Port-Sudan town based on the chemical analysis of groundwater along the coastal zone. The brackish groundwater along the coastal plain may represent one of the available water resources that can help to solve the problem of shortage in water supply. The interaction is determined near the sea coast at Khor Mog and Khor Salalab, where sea water reaches a maximum value of 16% and 14% of the total amount of water using ClCO3+HCO3 and ClfCls ratios, respectively. The boundary between the fresh and the brackish water was estimated to take place at about 8 km from the sea coast, where the interface between fresh and saline water is calculated at a depth of 200m below the ground surface at one km away from the sea shore. The groundwater along the coastal zone in the study area is classified as Ca+2, Na+, Cl-, SO4-2 water type. less
Urban CALculator Model (UrbanCALM) - Consistent and Efficient Framework for Urban Water Balance Analysis and Reporting: 2. Verification and Application
On Friday, 1st of May, 2015. 11:16:44 AM
By Chandrika Jayatilaka
Topic: GIS and modeling applications in river engineering
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AbstractThe verification of UrbanCALM was carried out based on a case study of its application to the Melbourne Region in Victoria, Australia. This region is read more
The verification of UrbanCALM was carried out based on a case study of its application to the Melbourne Region in Victoria, Australia. This region is served by a complex water system formed by integrated operations of multiple urban water utilities. Results demonstrated that UrbanCALM provides a user-friendly tool which enabled stepwise and systematic representation and evaluation of the Melbourne regional water system in 2012-2013. The study presented useful features in UrbanCALM such as the multiple checks provided to identify gaps and anomalies in usage of urban water data, which enable consistent and accurate interpretation of flows and urban water balance evaluations. The transferability and capabilities of the UrbanCALM framework were tested via its application to six major Australian population centres/cities reported on in the National Water Account. These urban centres / regions are served by water systems with varying level of complexity in terms of: area served; water intake, transfers and supplies for use; and wastewater collection, treatment, discharge and recycling. The study demonstrated that UrbanCALM provides ‘one consistent framework’ flexible and applicable in a consistent manner to ‘six major urban regions. In conclusion, UrbanCALM facilitates consistent and efficient water balance evaluations and strengthens the ability of agencies such as the Bureau of Meteorology to produce high quality water information reporting products. The framework is applicable to any urban water system nationally and internationally. It enables insights, provides transparency and better understanding of the urban system, and thus it can be recognised as a useful tool for urban water managers to address the needs of growing urban centres and populations. This study reveals the strong potential for its broad application across all Australian urban centres as well as internationally. less
The Potential Impacts of Low Releases From Nasser Lake Due to Climate Changes on Irrigation Pump Stations Along The Nile River
On Friday, 1st of May, 2015. 11:16:44 AM
By Amir Mobasher
Topic: Enviromental aspects of river engineering
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AbstractIn terms of the significance of the Nile River, this research was commenced with the impartial of in-vestigating the potential impacts of low releases read more
In terms of the significance of the Nile River, this research was commenced with the impartial of in-vestigating the potential impacts of low releases from Nasser Lake, due to climate changes, on irriga-tion pump stations along the river. Accordingly, the paper focuses on the effect of low flows on the pump station water supply. During this research, pump stations, for irrigation purposes, along the Nile River from Old Aswan Dam (OAD) to Delta Barrage were appraised according to their design and critical water level to determine the potential for the expected problems due to passing low discharges as a result of climate changes. less
Estimation of the Best fit Rainfall-Runoff Relationship for the Upper Blue Nile Basin
On Friday, 1st of May, 2015. 11:16:44 AM
By Assem Afify
Topic: Enviromental aspects of river engineering
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AbstractThe Blue Nile water is the main source of the Nile River, which contributes approximately 60% of the Nile River flow arriving at Aswan Dam, Egypt. Rai read more
The Blue Nile water is the main source of the Nile River, which contributes approximately 60% of the Nile River flow arriving at Aswan Dam, Egypt. Rainfall-runoff relationships were obtained to predict the stream flow at the shed outlet using both simple linear and nonlinear regression models. Meteorological records (1908-2007) for the total monthly rainfall of representative 33 NOAA’ stations were used along with hydrological data series (1966-2005) for the gauge outflow at El-Deim. Last eight years of rainfall and stream flow records were used for the validation of the obtained rainfall-runoff relations. Monthly runoff coefficients were estimated with an overall average of 20%. The best fit rainfall-runoff relations with two trends (rising and falling stage) were observed and presented in the paper. less
Nile Water Science & Engineering Journal
