scholarly journals Analyzing runoff processes through conceptual hydrological modeling in the Upper Blue Nile Basin, Ethiopia

2014 ◽  
Vol 18 (12) ◽  
pp. 5149-5167 ◽  
Author(s):  
M. Dessie ◽  
N. E. C. Verhoest ◽  
V. R. N. Pauwels ◽  
T. Admasu ◽  
J. Poesen ◽  
...  
Keyword(s):  
Water Resources ◽  
Rainfall Runoff ◽  
Nile Basin ◽  
Blue Nile ◽  
Direct Runoff ◽  
Blue Nile Basin ◽  
Hard Soil ◽  
Production Areas ◽  
Runoff Production ◽  
Upper Blue Nile Basin

Abstract. Understanding runoff processes in a basin is of paramount importance for the effective planning and management of water resources, in particular in data-scarce regions such as the Upper Blue Nile. Hydrological models representing the underlying hydrological processes can predict river discharges from ungauged catchments and allow for an understanding of the rainfall–runoff processes in those catchments. In this paper, such a conceptual process-based hydrological model is developed and applied to the upper Gumara and Gilgel Abay catchments (both located within the Upper Blue Nile Basin, the Lake Tana sub-basin) to study the runoff mechanisms and rainfall–runoff processes in the basin. Topography is considered as a proxy for the variability of most of the catchment characteristics. We divided the catchments into different runoff production areas using topographic criteria. Impermeable surfaces (rock outcrops and hard soil pans, common in the Upper Blue Nile Basin) were considered separately in the conceptual model. Based on model results, it can be inferred that about 65% of the runoff appears in the form of interflow in the Gumara study catchment, and baseflow constitutes the larger proportion of runoff (44–48%) in the Gilgel Abay catchment. Direct runoff represents a smaller fraction of the runoff in both catchments (18–19% for the Gumara, and 20% for the Gilgel Abay) and most of this direct runoff is generated through infiltration excess runoff mechanism from the impermeable rocks or hard soil pans. The study reveals that the hillslopes are recharge areas (sources of interflow and deep percolation) and direct runoff as saturated excess flow prevails from the flat slope areas. Overall, the model study suggests that identifying the catchments into different runoff production areas based on topography and including the impermeable rocky areas separately in the modeling process mimics the rainfall–runoff process in the Upper Blue Nile Basin well and yields a useful result for operational management of water resources in this data-scarce region.

scholarly journals Analyzing runoff processes through conceptual hydrological modelling in the Upper Blue Nile basin, Ethiopia

2014 ◽  
Vol 11 (5) ◽  
pp. 5287-5325 ◽  
Author(s):  
M. Dessie ◽  
N. E. C. Verhoest ◽  
V. R. N. Pauwels ◽  
T. Admasu ◽  
J. Poesen ◽  
...  
Keyword(s):  
Water Resources ◽  
Rainfall Runoff ◽  
Nile Basin ◽  
Blue Nile ◽  
Direct Runoff ◽  
Blue Nile Basin ◽  
Hard Soil ◽  
Production Areas ◽  
Runoff Production ◽  
Upper Blue Nile Basin

Abstract. Understanding runoff processes in a basin is of paramount importance for the effective planning and management of water resources, in particular in data scarce regions of the Upper Blue Nile. Hydrological models representing the underlying hydrological processes can predict river discharges from ungauged catchments and allow for an understanding of the rainfall–runoff processes in those catchments. In this paper, such a conceptual process-based hydrological model is developed and applied to the upper Gumara and Gilgel Abay catchments (both located within the Upper Blue Nile basin, the Lake Tana sub-basin) to study the runoff mechanisms and rainfall–runoff processes in the basin. Topography is considered as a proxy for the variability of most of the catchment characteristics. We divided the catchments into different runoff production areas using topographic criteria. Impermeable surfaces (rock outcrops and hard soil pans, common in the Upper Blue Nile basin) were considered separately in the conceptual model. Based on model results, it can be inferred that about 65% of the runoff appears in the form of interflow in the Gumara study catchment, and baseflow constitutes the larger proportion of runoff (44–48%) in the Gilgel Abay catchment. Direct runoff represents a smaller fraction of the runoff in both catchments (18–19% for the Gumara, and 20% for the Gilgel Abay) and most of this direct runoff is generated through infiltration excess runoff mechanism from the impermeable rocks or hard soil pans. The study reveals that the hillslopes are recharge areas (sources of interflow and deep percolation) and direct runoff as saturated excess flow prevails from the flat slope areas. Overall, the model study suggests that identifying the catchments into different runoff production areas based on topography and including the impermeable rocky areas separately in the modeling process mimics well the rainfall–runoff process in the Upper Blue Nile basin and brings a useful result for operational management of water resources in this data scarce region.

scholarly journals Impact of Meteorological Drought in Upper Blue Nile Basin on the Hydrological Drought of Nile River in Egypt

2020 ◽  
Vol 9 (6) ◽  
pp. 50-55
Keyword(s):  
Water Resources ◽  
Pearson Correlation ◽  
Meteorological Drought ◽  
Hydrological Drought ◽  
Drought Indices ◽  
Nile River ◽  
Nile Basin ◽  
Blue Nile ◽  
Blue Nile Basin ◽  
Upper Blue Nile Basin

Precipitation over the Upper Blue Nile Basin in Ethiopia contributes with 85% of the Nile river which provides 93% of Egypt’s conventional water resources. This study aims at assessing the meteorological drought in different locations in the Upper Blue Nile Basin and their relationship with the hydrological drought of Nile river in Egypt. The metrological drought was calculated by the Standard Precipitation Index (SPI) at five stations inside and close to the Upper Blue Nile Basin in Ethiopia, whereas the hydrological drought was calculated by the Streamflow Drought Index (SDI) at Dongola station at Nasser lake entrance. Both indices were calculated using the Drought Indices Calculator (DrinC) software. The selected study period was from 1973 to 2017 based on the availability of recorded data for meteorological stations in Ethiopia, and the streamflow for Dongola station. The data was categorized for each station by considering time periods of 1, 3, 6, 9, and 12 months based on their homogeneity. The correlation between SPI and SDI was evaluated using the Pearson correlation coefficient. The results showed a correlation between SPI for the five stations in the Upper Blue Nile Basin and SDI for Dongola station, where Gore station represented the highest frequency of significance at different time scales especially at the 3-months’ scale. The results confirm the relationship between SPI at Gore Station and SDI at Dongola Station, which means that the hydrological drought in Egypt is highly affected by the meteorological drought in the area surrounding Gore station. The paper recommends improving techniques for monitoring and overseeing drought hazards and assessing more meteorological stations to accurately predict climate change variations in Upper Blue Nile Basin and its effect on Egypt’s water resources.

scholarly journals Advances in water resources research in the Upper Blue Nile basin and the way forward: A review

2018 ◽  
Vol 560 ◽  
pp. 407-423 ◽  
Author(s):  
Yihun Taddele Dile ◽  
Sirak Tekleab ◽  
Essayas K. Ayana ◽  
Solomon G. Gebrehiwot ◽  
Abeyou W. Worqlul ◽  
...  
Keyword(s):  
Water Resources ◽  
Nile Basin ◽  
Blue Nile ◽  
Blue Nile Basin ◽  
The Way ◽  
Upper Blue Nile Basin

scholarly journals Effects of climate change on water resources in the upper Blue Nile Basin of Ethiopia

Heliyon ◽  
2018 ◽  
Vol 4 (9) ◽  
pp. e00771 ◽  
Author(s):  
Vincent Roth ◽  
Tatenda Lemann ◽  
Gete Zeleke ◽  
Alemtsehay Teklay Subhatu ◽  
Tibebu Kassawmar Nigussie ◽  
...  
Keyword(s):  
Climate Change ◽  
Water Resources ◽  
Nile Basin ◽  
Blue Nile ◽  
Blue Nile Basin ◽  
Upper Blue Nile Basin

scholarly journals Modelling rainfall–runoff processes of the Chemoga and Jedeb meso-scale catchments in the Abay/Upper Blue Nile basin, Ethiopia

2015 ◽  
pp. 1-18 ◽  
Author(s):  
Sirak Tekleab ◽  
Stefan Uhlenbrook ◽  
Hubert H.G. Savenije ◽  
Yasir Mohamed ◽  
Jochen Wenninger
Keyword(s):  
Rainfall Runoff ◽  
Nile Basin ◽  
Blue Nile ◽  
Blue Nile Basin ◽  
Meso Scale ◽  
Upper Blue Nile Basin

scholarly journals Tailoring seasonal climate forecasts for hydropower operations in Ethiopia's upper Blue Nile basin

2010 ◽  
Vol 7 (3) ◽  
pp. 3765-3802 ◽  
Author(s):  
P. Block
Keyword(s):  
Water Resources ◽  
Coupled System ◽  
Precipitation Forecast ◽  
Risk Averse ◽  
Nile Basin ◽  
Explicit Integration ◽  
Blue Nile ◽  
Water Resources Systems ◽  
Blue Nile Basin ◽  
Upper Blue Nile Basin

Abstract. Explicit integration of seasonal precipitation forecasts into water resources operations and planning is practically nonexistent, even in regions of scarcity. This is often attributable to water manager's tendency to act in a risk averse manner, preferring to avoid consequences of poor forecasts, at the expense of unrealized benefits. Convincing demonstrations of forecast value are therefore desirable to support assimilation into practice. A dynamic coupled system, including forecast, rainfall-runoff, and hydropower models, is applied to the upper Blue Nile basin in Ethiopia to compare benefits and reliability generated by actual forecasts against a climatology-based approach, commonly practiced in most water resources systems. Processing one hundred decadal sequences demonstrates superior forecast-based benefits in 68 cases, a respectable advancement, however benefits in a few forecast-based sequences are noticeably low, likely to dissuade manager's adoption. A hydropower sensitivity test reveals a propensity toward poor-decision making when forecasts over-predict wet conditions. Tailoring the precipitation forecast to highlight critical dry predictions minimizes this inclination, resulting in 97% of the sequences favoring the forecast-based approach. Considering managerial risk preferences for the system, even risk-averse actions, if coupled with forecasts, exhibits superior benefits and reliability compared with risk-taking tendencies relying on climatology.

Sign in / Sign up

Export Citation Format

Share Document