Water resource assessment along the Blue Nile River, north Africa with a one-dimensional model

Abstract

The water resource of the Blue Nile River in north Africa is under increasing pressure due to rapid population growth and economic development. The situation is aggravated by a lack of coordinated management and governance, partly caused by incomplete knowledge of the water supplies, uses and needs. Proper water management is particularly important now, considering the recently completed and planned mega dams on the Blue Nile River network. This paper reports on the construction of a one-dimensional hydrodynamic model covering the entire Blue Nile River system, from Lake Tana to the confluence with the White Nile, with the aim of quantifying water availability throughout the year, for different conditions. The work included an extensive field measurement campaign along the Blue River and its tributaries, both in Ethiopia and Sudan. Calibrated and validated with independent datasets, the model was used to quantify water uses in the period 2008-2010, which were then compared with the official figures. The results show that the dry season is characterised by extra water losses that should be taken into account when quantifying water needs, especially during the filling up phase of new reservoirs.

Integrated Modeling of Land and Water Resources in two African Catchments

“…Another way of putting this is that agricultural land, which increases surface runoff, might have expanded more than what was represented using either the static or the semi-dynamic land-use maps. The overestimation of the simulated flow compared to the observation during the dry (low-flow) seasons may partly be attributed to the increasing use of ground water abstraction to be expected from the increased human and livestock populations in the region (Abera et al, 2017;Ali et al, 2014). In addition, the natural vegetation cover in the catchment in particular and in the basin in general is being replaced with eucalyptus (Eucalyptus grandis and Pinus) trees (Gebrehiwot, 2015;Tekleab et al, 2014a).…”

Editorial

“…The issue begins with a contribution on the use of a permeable reactive barrier to treat acid mine water in South Africa (Ekolu et al, 2014), followed by a contribution by Dhakal et al (2014) on the ongoing development of the modified unit hydrograph method. There then follows a paper by Ali et al (2014) on water resources modelling in the Blue Nile, after which Bieroza et al (2014) address matters relating to the stable isotopic composition of raw and treated water in the UK. The international character of the authorship is also reflected within individual author groups in most cases, with international case studies often being worked on by authors from a range of countries, sharing ideas on best practice.…”

“…As in many countries where a single large catchment covers many international territories, decisions on water resources must be guided by the proper scientific understanding of the science and engineering driving water availability and water demand, both of which are in a state of continuous development. Similar to Ekolu et al (2014), Ali et al (2014) fundamentally make related points about the long-term sustainability of water resources for a range of different uses.The final full research paper discusses the stable isotopic composition of fresh water, which according to Bieroza et al (2014) has received little attention to date in comparison with similar studies of precipitation. They demonstrate how important is the effect of catchment controls on the stable isotopic composition of raw waters at the inlets to 16 different water treatment works in the UK.…”

“…Clearly, such an approach is of interest in the UK and elsewhere where there are concerns about the increased incidence of prolonged rainfall events of higher intensity than for what the drainage infrastructure was designed. Ali et al (2014) assess the water resources of the Blue Nile catchment using a one-dimensional model. Readers will be interested to note that their model is underpinned by a large data set of field measurements that can sometimes be missing from studies of this type.…”

“…As in many countries where a single large catchment covers many international territories, decisions on water resources must be guided by the proper scientific understanding of the science and engineering driving water availability and water demand, both of which are in a state of continuous development. Similar to Ekolu et al (2014), Ali et al (2014) fundamentally make related points about the long-term sustainability of water resources for a range of different uses.…”