Supporting agricultural irrigation management in East Africa using eco-hydrological modelling: the WATDEV project

Project WATDEV – Climate Smart WATer Management and Sustainable DEVelopment for Food and Agriculture in East Africa (https://www.watdev.eu/) – is an EU-funded partnership between African and European institutions, aiming to enhance sustainability of agricultural water management and resilience of agro ecosystems to climate change in East Africa. The project aims to improve the knowledge on agricultural water management of National Ministries and Research Institutions, and help farmers and local actors, cooperatives and Water User Associations implement innovative/sustainable solutions and improve skills on water management.

The project developed and applied an eco-hydrological model to four irrigation case studies in Egypt, Ethiopia, Kenya and Sudan. This model was used to simulate the impact of Best Management Practices (BMPs), selected and co-developed with local water managers and farmers, on environmental indicators such as crop yield, water demands and nutrient use. Economic indicators (e.g. return on investment) were also calculated over the model results. The BMP impacts were then presented to stakeholders both to validate results and to help them in defining an implementation protocol to be transferred to farmers outside the case study areas.

In general, most stakeholders selected BMPs falling in one of three broad categories:

• changes in cultivation practices, related with new crops, crop rotations, or improved fertilization;
• agroforestry, related with planting permanent crops alongside annual crops and using trees for erosion control;
• water management, related with increasing water availability and water use efficiency through improvements in the irrigation system and/or the adoption of water saving practices.

However, the details of each BMP were very different between sites, indicating a strong desire for customization.

Preliminary results indicate that the impacts of BMPs strongly depend on the local contexts, driven by the need to address the prevailing bio-physical and socio-economic challenges. In Egypt and Kenya, the selected BMPs are not expected to increase yield, since crops usually have sufficient water and nutrients. They are, however, expected to provide more reliable water access, decrease fertilization costs and diversify crops. In Ethiopia and Sudan, however, the selected BMPs did lead to increases in yield and water use efficiency through a better adaptation of crops and practices to local climate conditions.