| 1. |
- Abdelhady, Dalia, et al.
(författare)
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The Nile and the Grand Ethiopian Renaissance Dam: Is There a Meeting Point between Nationalism and Hydrosolidarity?
- 2015
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Ingår i: Journal of Contemporary Water Research and Education. - 1936-704X. ; 155:1, s. 73-82
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Tidskriftsartikel (refereegranskat)abstract
- The soon-to-be completed Grand Ethiopian Renaissance Dam (GERD), which will be the largest hydroelectric power plant and among the largest reservoirs in Africa, has highlighted the need for expanding traditional integrated water resources management to better include the cultural, social, and political complexities of large water infrastructure in development projects. The GERD will store a maximum of 74 billion cubic meters of water corresponding to approximately the average annual outflow of the Nile from the Aswan high dam. Undoubtedly, the GERD will be vital for energy production and a key factor for food production, economic development, and poverty reduction in Ethiopia and the Nile Basin. However, the GERD is also a political statement that in one stroke has re-written the hydropolitical map of the Nile Basin. The GERD has become a symbol of Ethiopian nationalism or “renaissance” (hidase in Amharic). A contrasting concept to nationalism is hydrosolidarity. This concept has been put forward to better stress equitable use of water in international water management challenges that would lead to sustainable socioeconomic development. We use the opposing notions of nationalism and hydrosolidarity at three different scales, everyday politics, state policies, and interstate and global politics to analyse some aspects of the new hydropolitical map of the Nile Basin. We argue that nationalism and national interests are not necessarily negative standpoints but that there may instead be a meeting point where regional and national interests join with hydrosolidarity principles. We believe that this meeting point can maximize not only the common good, but also the good from a national interest point of view. For this, it is important not increase collaboration instead of being locked in to the historical narrative of nationalistic culture and historical discourse. This would benefit and improve future sustainability.
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| 2. |
- Aboulila, Tarek Selim, et al.
(författare)
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Assessment of inter-plant emitter distance and effects of irrigation water salinity on APRDI using Hydrus-2D
- 2011
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Ingår i: European Journal of Scientific Research. - 1450-216X. ; 58, s. 266-277
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Tidskriftsartikel (refereegranskat)abstract
- Abstract in UndeterminedModern irrigation techniques are becoming increasingly important in water-scarce countries. In this study, a two-dimensional water and solute transport model, Hydrus-2D, was used to assess the impact of inter-plant emitter distance (IPED) and irrigation water salinity on soil moisture and salinity distribution as well as on water balance components under alternate partial root-zone surface drip irrigation (APRDI) of tomato growing in loamy sand soil. Three IPED (20, 30, and 40 cm) and three irrigation water salinity levels (0, 1, and 2 dS/m) were used to execute different simulation scenarios. Simulation results indicated that the fluctuations in water content within the root zone were more pronounced in case of 20 cm IPED. The root water uptake increased as the IPED decreased. Using brackish irrigation water in APRDI caused significant augmentation in soil salinity in the top soil layer especially at the location of plant. The impact of irrigation water salinity on root water uptake increased as the IPED increased. As irrigation water salinity increased the root water uptake decreased. At plant location, soil salinity reached its highest values at the top soil layer in case of 30 and 40 cm IPED with brackish irrigation water. However, high soil salinity values were observed between the 40 and 65 cm depths in case of 20 cm IPED. Based on the results, it appears that APRDI with non-saline irrigation water is more effective with short IPED considering that approximately half of the root system was exposed to drying cycle. In addition, short IPED is recommended in APRDI when using brackish irrigation water especially for plants with shallow root system taking into account crop salinity tolerance.
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| 3. |
- Aboulila, Tarek Selim, et al.
(författare)
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Field experiment and numerical simulation of point source irrigation with multiple tracers.
- 2013
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Ingår i: International Journal of Sustainable Water and Environmental Systems. - 1923-7545.
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Tidskriftsartikel (populärvet., debatt m.m.)abstract
- In this study, three plots in sandy soil in northern Tunisia were irrigated by a single irrigation dripper with a solution containing dye and bromide for three successive hours. Fifteen hours after ceasing of infiltration, horizontal 5 cm trenches were dug. Dye pattern, bromide concentration, and water content were recorded. Indication of preferential flow due to water repellency of initial dry soil was found during the early stages of infiltration. However no deep preferential flow occurred. This enables the use of drip irrigation to improve the sustainability of irrigation systems. Numerical simulation using Hydrus-2D was conducted for the field experiment. It was found that in both field experiments and numerical simulation the mobility of the bromide is different from the mobility of dye; the dye was retarded approximately twice by volume compared to bromide. The simulation results support the use of Hydrus-2D as a roughly, rapid and labor saving tool for investigation tracers’ mobility in sandy soil under point source irrigation.
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| 4. |
- Aboulila, Tarek Selim, et al.
(författare)
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Influence of geometric design of alternate partial root-zone subsurface drip irrigation (APRSDI) with brackish water on soil moisture and salinity distribution
- 2012
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Ingår i: Agricultural Water Management. - : Elsevier BV. - 1873-2283 .- 0378-3774. ; 103, s. 182-190
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Tidskriftsartikel (refereegranskat)abstract
- In alternate partial root-zone irrigation (APRI) a significant amount of irrigation water can be saved without considerable yield reduction. In this paper, Hydrus-2D/3D was used to investigate the impact of geometric design of alternate partial root-zone subsurface drip irrigation (APRSDI) with brackish water for growing tomato on soil moisture and salinity distribution. Three inter-plant emitter distances (IPED; 20, 30, and 40 cm), two emitter depths (10 and 20 cm), and three irrigation water salinity levels (0, 1, and 2 dS m-1) were used to implement the proposed simulation scenarios in loamy sand soil during a 40-day simulation period. The simulation results showed that higher soil moisture content was found beneath the plant trunk in case of 20 cm (short IPED) and near the domain border in case of 30 and 40 cm IPED. Short IPED guarantees more water in the maximum root density zone. A deeper wetting front occurred for deep emitter depth, while the wetting front reached the soil surface for shallow emitter depth. Salinity results revealed that as irrigation water salinity increased, the salinity in the top soil increased. In addition, the salinity at the soil surface increased as IPED and emitter depth increased. Higher root water uptake rates were recorded in the case of 20 cm IPED while the emitter depth did not show any considerable effect on root water uptake rates. Moreover, the applied irrigation water was fully consumed by the plant in case of short IPED. Emitter depth and salinity of irrigation water had negligible effect on amount of irrigation water extracted by plant roots and percolated amount below the bottom boundary of the flow domain. Overall, short IPED is recommended in APRSDI with or without brackish irrigation water regardless of the emitter depth.
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| 5. |
- Aboulila, Tarek Selim, et al.
(författare)
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Numerical evaluation of subsurface trickle irrigation with brackish water
- 2013
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Ingår i: Irrigation Science. - : Springer Science and Business Media LLC. - 0342-7188 .- 1432-1319. ; 31:5, s. 1125-1137
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Tidskriftsartikel (refereegranskat)abstract
- In this study, an assessment for a proposed irrigation system in the El-Salam Canal cultivated land, Egypt, was conducted. A numerical model (HYDRUS-2D/3D) was applied to investigate the effect of irrigation amount, frequency, and emitter depth on the wetted soil volume, soil salinity levels, and deep percolation under subsurface trickle irrigation (SDI) of tomato growing with brackish irrigation water in three different soil types. The simulations indicated that lower irrigation frequency increased the wetted soil volume without significant increase in water percolate below the plant roots. Deep percolation decreased as the amount of irrigation water and emitter depth decreased. With the same amount of irrigation water, the volume of leached soil was larger at lower irrigation frequency. The salinity of irrigation water under SDI with shallow emitter depth did not show any significant effect on increasing the soil salinity above tomato crop salt tolerance. Based on the results, it appears that the use of SDI with brackish irrigation water is an effective method for growing tomato crop in El-Salam Canal cultivated land especially with shallow emitter depth.
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| 6. |
- Aboulila, Tarek Selim, et al.
(författare)
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Simulation of soil water and salinity distribution under surface drip irrigation
- 2013
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Ingår i: Irrigation and Drainage. - : Wiley. - 1531-0361 .- 1531-0353. ; 62:3, s. 352-362
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Tidskriftsartikel (refereegranskat)abstract
- Higher crop production and higher water use efficiency are usually achieved simultaneously with surface drip irrigation compared to other surface irrigation methods. With increasing competition for fresh water nowadays, there is also a need for greater use of brackish water in agriculture. Effects of soil hydraulic properties, initial soil moisture content ( ), and the irrigation regime on soil water and salinity distribution under surface drip irrigation (DI) with brackish irrigation water for growing tomato in saline soil were investigated using HYDRUS-2D/3D model. Simulation scenarios were conducted including three soil types (sand, loamy sand, and sandy loam), two irrigation regimes (daily and on alternate-day irrigation), and two values. Simulation results revealed that the effect of the irrigation regime on the wetting patterns differed according to the soil’s hydraulic properties while the effect of the initial soil moisture content vanished after a few days. Alternate-day regime is suitable for fine-texture soil. Soil salinity patterns showed that the irrigation regime and value did not show any significant effect on soil salinity distribution under drip irrigation with brackish water. Higher soil salinity values occurred along the soil surface by the end of the simulation period. These higher values were closer to the emitter in sand as compared to loamy sand and sandy loam. Water balance calculations showed that as the initial soil moisture content increased, the free drainage component increased. However, the irrigation regime and initial soil moisture content value did not affect the evaporation rate and root water uptake rate.
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| 7. |
- Aboulila, Tarek Selim, et al.
(författare)
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Soil water and salinity distribution under different treatments of drip irrigation.
- 2013
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Ingår i: Soil Science Society of America Journal. - : Wiley. - 0361-5995. ; 77:4, s. 1144-1156
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Tidskriftsartikel (populärvet., debatt m.m.)abstract
- In this study, field experiments and numerical simulations for different drip irrigation treatments in a sandy loam soil were conducted to investigate soil water and salinity distribution as well as dye infiltration patterns. Three treatments, surface drip irrigation without and with plastic mulch (T1 and T2, respectively); and subsurface drip irrigation (T3), were used. In addition, daily and bi-weekly irrigation regimes were considered during performing each treatment. After ceasing the designed irrigation schedule of each treatment, horizontal soil sections were dug with 10 cm intervals. Then, dye patterns were captured using a digital camera and soil water and pore water electric conductivity were measured by a WET-sensor. Experiments results revealed that maximum dye infiltration depth and maximum dye coverage volume occurred during the bi-weekly irrigation regime and in T3. Daily irrigation regime kept the top soil layer moist with adequate amount of soil water as compared to bi-weekly regime. Moreover, T2 provided higher soil water content within the soil domain as compared to other treatments. The simulation results also demonstrated that model prediction for soil moisture distribution within the flow domain was excellent. Furthermore, T2 and daily irrigation showed lower salinity levels in the flow domain as compared to other irrigation treatments and regimes. In sum, mulching treatment with daily irrigation regime is recommended for arid areas over other drip irrigation treatments and regimes. In addition, HYDRUS-2D/3D can be used as a fast and cost effective assessment tool for water flow and salt movement for specific sites having similar soil conditions.
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| 8. |
- Aboulila, Tarek Selim, et al.
(författare)
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Spatial Analysis of Infiltration Experiment
- 2011
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Ingår i: Australian Journal of Basic and Applied Sciences. - 1991-8178. ; 5:7, s. 729-742
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Tidskriftsartikel (refereegranskat)abstract
- Developing correlations between various soil parameters are considered the major challenge to diminish time and cost associated with field measurements. Soil hydraulic and physical properties were extensively characterized using tension disc infiltrometer and soil sampling in a silty clay agricultural field in Kalaat El-Andalous, Tunisia. Tension disc infiltrometer experiments were conducted at 109 plots with two supply water potentials (-30,-60 mm) at each plot to determine the hydraulic conductivity, sorptivity, capillary length, and matric flux potential. In addition, soil samples were analyzed to determine the soil bulk density, and water content. From the statistical and spatial analysis for the different parameters, it was found that the soil hydraulic parameters had larger variability than bulk density. Sorptivity, capillary length, matric flux potential, and bulk density had lager variance with the distance between the plots. No correlation was found between bulk density and the soil hydraulic parameters, nor could the soil hydraulic parameters be correlated to each other.
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| 9. |
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Advances in Data-Based Approaches for Hydrologic Modeling and Forecasting
- 2010
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Samlingsverk (redaktörskap) (refereegranskat)abstract
- This book comprehensively accounts the advances in data-based approaches for hydrologic modeling and forecasting. Eight major and most popular approaches are selected, with a chapter for each stochastic methods, parameter estimation techniques, scaling and fractal methods, remote sensing, artificial neural networks, evolutionary computing, wavelets, and nonlinear dynamics and chaos methods.These approaches are chosen to address a wide range of hydrologic system characteristics, processes, and the associated problems. Each of these eight approaches includes a comprehensive review of the fundamental concepts, their applications in hydrology, and a discussion on potential future directions.
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| 10. |
- Berndtsson, Ronny, et al.
(författare)
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Drivers of changing urban flood risk : A framework for action
- 2019
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Ingår i: Journal of Environmental Management. - : Elsevier. - 0301-4797 .- 1095-8630. ; 240, s. 47-56
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Tidskriftsartikel (refereegranskat)abstract
- This study focuses on drivers for changing urban flood risk. We suggest a framework for guiding climate change adaptation action concerning flood risk and manageability in cities. The identified key drivers of changing flood hazard and vulnerability are used to provide an overview of each driver's impact on flood risk and manageability at the city level. We find that identified drivers for urban flood risk can be grouped in three different priority areas with different time horizon. The first group has high impact but is manageable at city level. Typical drivers in this group are related to the physical environment such as decreasing permeability and unresponsive engineering. The second group of drivers is represented by public awareness and individual willingness to participate and urbanization and urban sprawl. These drivers may be important and are manageable for the cities and they involve both short-term and long-term measures. The third group of drivers is related to policy and long-term changes. This group is represented by economic growth and increasing values at risk, climate change, and increasing complexity of society. They have all high impact but low manageability. Managing these drivers needs to be done in a longer time perspective, e.g., by developing long-term policies and exchange of ideas.
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