EGU2020-22061, updated on 12 Jun 2020
https://doi.org/10.5194/egusphere-egu2020-22061
EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

Flood-based Farming as Affected by Hydrological Deficit in the Semiarid Lowlands of Northern Ethiopia

Emnet Negash1, Jan Nyssen2, Girmay Gebresamuel3, Tesfa-alem Embaye4, Alick Nguvulu5, Hailemariam Meaza6, Misgina Gebrehiwot6, Biadglign Demisse6,7, Tesfaalem Gebreyohannes6, and Amanuel Zenebe3
Emnet Negash et al.
  • 1Institute of Climate and Society, Mekelle University, Mekelle, Ethiopia (emnet.negash@mu.edu.et)
  • 2Department of Geography, Ghent University, Gent, Belgium
  • 3Department of Land Resource Management and Environmental Protection, Mekelle University, Mekelle, Ethiopia
  • 4Institute of Water and Environment, Mekelle University, Mekelle, Ethiopia
  • 5Department of Geomatics Engineering, Copperbelt University, Kitwe, Zambia
  • 6Department of Geography and Environmental Studies, Mekelle University, Mekelle, Ethiopia
  • 7Institute of Geo-information and Earth Observation Science, Mekelle University, Mekelle, Ethiopia

Agriculture remains the dominant source of food production and the livelihood foundation for majority of the rural poor in the sub-Saharan Africa, including Ethiopia. Access to agricultural-water is, however, a limitation hindering crop productivity and end food insecurity in the drylands. In rain-deficit lowlands such as in the Raya-valley, flood-based farming is a means of improving crop production. Such spate irrigation systems grow in importance; though the effects of headwater hydrological deficit on flood-farming systems are lacking evidence. The present work investigates the impacts of headwater hydrological deficit on spate-irrigated agriculture in Tsge’a spate systems. Canal length and area of spate-irrigated agriculture along Guguf river for the 1980s and 2010s were tracked using Global Positioning System; while runoff trend analysed using linear regression. Annual volume of flash-flood shrunk by 7.36x106 m3. This is mainly due to changing climate and increasing water retention by the soil and humans at the escarpment. As a result, length of canals and area of spate-based farms downstream declined by 1.37 km (35%) and 1540 ha (57.5%), respectively, only in three decades time. This corresponds to an average withdrawal of -44 ha yr-1. A 1x106 m3 decline in flash-flood caused a 366.4 ha decline in spate-based farms. Moreover, farm fields located next to the river course are less affected, as compared to farms on the tail of the scheme. If the current trend continues, there is likely a high risk that the remaining farms currently receiving flood may run out of spate systems. Therefore, flood management technologies are needed to optimize the efficiency of soil moisture in the spate system.

The abstract is based on Negash, E., Gebresamuel, G., Embaye, T., Nguvulu, A., Meaza, H., Gebrehiwot, M., Demisse, B., Gebreyohannes, T., Nyssen, J., & Zenebe, A. (2020). Impact of headwater hydrological deficit on the downstream flood-based farming system in northern Ethiopia. Irrigation and Drainage, In Press.

How to cite: Negash, E., Nyssen, J., Gebresamuel, G., Embaye, T., Nguvulu, A., Meaza, H., Gebrehiwot, M., Demisse, B., Gebreyohannes, T., and Zenebe, A.: Flood-based Farming as Affected by Hydrological Deficit in the Semiarid Lowlands of Northern Ethiopia, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-22061, https://doi.org/10.5194/egusphere-egu2020-22061, 2020

Corresponding presentation materials formerly uploaded have been withdrawn.