Flood Forecast and Early Warning

The overall objective of the project has been to develop a demonstration seasonal hydrological forecast system for the Eastern Nile (EN) Basin. The system monitors climate and hydrology in near real-time, and produces climate and hydrological forecasts on a seasonal (out to 6 months) basis aimed at drought forecasting. The system is updated daily, and runs about 1–2 days behind real-time, which is based on the availability and latency of the contributing data products.

This report has been automatically generated by the Flood and Drought Data Portal1. This report contains the latest satellite imagery used to monitor precipitation, soil moisture, and vegetation health in order to support drought early warning systems. It aims at describing the current drought situation in the basin with the objective of providing better information to manage emerging crop losses or water shortages and prevent or mitigate possible related disasters.

This presentation is presented for the Kick-off meeting of the project Eastern Nile Drought Monitoring, Prediction and Early Warning System. It included introduction of the project, its purpose expected outcomes and deliverables and also the proposed work plan for the consulting firm with the deliverables at each phase.

The Eastern Nile (EN) Flood Preparedness and Early Warning Project (FPEW) under the Integrated Development of the Eastern Nile (IDEN) is an ongoing project that is being implemented in two phases. The FPEW has created a regional Flood Forecast and Early Warning System (FFEWS) and has strengthened national offices both in terms of capacity and equipment.

The objectives of this project are; to expand, enhance and develop a unified flood forecast system for EN basin services to new, so far unsupported flood prone communities and areas, particularly South Sudan and TSA sub-basin, to ensure a robust issuing and warning system that effectively minimize loss of life and damage, to support other studies under FFEW that contributes in addressing flash flood, Stakeholder analysis and flood related DSS development.

The works to enhance the EN-FFEWS have substantially improved the forecast system and have given insights into the situation on the ground regarding flood information communication as well as flood response preparedness and resilience. On this basis, the above recommendations for further improvements and enhancements have been given.

This is the final report of the Flash Floods Consultancy for the EN basin. The report discusses the flash floods situation in the EN countries, flood types, flash floods prone sites, existing flood EWS, mitigation measures and ends up with guide lines for developing effective flash floods EWS to reduce the loss in human lives and properties in the region.

The present study project aims to ensure a robust forecasting, issuing and warning system that effectively minimize loss of life and damage by enhancing, expanding and developing a unified Flood Forecast and Early Warning (FFEW) system for EN basin. Further, to support other studies under FFEW that contribute in addressing flash flood, stakeholder analysis and flood related DSS development.

The study consists of three separate components. The first was the inception phase. This was mainly done to lay down the foundation of the flood forecasting and early warning programme in the country in regard to nature and status of the flood. The second phase consists of the dynamics, processes and the impacts of the floods. And the final component consists of the specific cases of floods in each and every country of the eastern Nile countries. For the case of South Sudan the third component study concentrated to the flash floods which happened between July and November 2019.

Groundwater holds the promise of closing the gap between water supply and demand, and in buffering the effects of climate variability. The other driver of interest around groundwater is the role that groundwater plays in addressing the SDG 6 target for drinking water. To reach this SDG 6 target, groundwater delivered thorough multiple delivery mechanisms (e.g. boreholes, springs, reticulated systems, dug wells) has a vital role to play. Groundwater use for socio-economic improvements is generally in a growing stage in Africa and in the Nile basin in particular. Experience elsewhere in the world (South East Asian countries) and in some cities in Sub-Saharan Africa show that this precious resource can rapidly degrade and depleted. A UNEP report (Morris et al., 2011) demonstrates that groundwater storage that provides the ultimate resources buffer is threatened with a double jeopardy - depletion and degradation. The pressure is already felt in the numerous small aquifers in the upper Nile riparian countries.

Groundwater monitoring of both levels and quality will depend on where the resource is currently being abstracted or where potential exists to develop its use for various purposes. A typical groundwater monitoring program will involve monthly analysis of both level and quality at key locations. The common practice is that; groundwater monitoring should have certain predefined objectives. The general objective of the monitoring program is to supply data for characterization of the regional groundwater systems, identification of trends in time and prediction of the regional impacts. The design of a cost effective and purposeful monitoring network largely depends on the stages of groundwater (aquifer) assessment and development, the importance of the aquifer, the threats on the aquifers, as well as the natural resilience and fragility of the aquifers. Figure 1 shows some general recommendation as to what type of monitoring is required depending on the degree of groundwater development. Design of groundwater monitoring network also depends on financial and institutional capacity to sustainably run monitoring network.

The Eastern Nile Basin has a special significance in the water resources management of the entire Nile Basin. The Eastern Nile basin contributes the largest volume of surface water flows, the largest amount of renewable groundwater resources and also the largest groundwater storage potential when it is compared with the other sub basins of the Nile. The aquifers in the Eastern Nile Groundwater basins and the other basins connected to the Eastern Nile groundwater basins collectively have a proven groundwater storage amounting to more than 210,000 Billion m3. While the upstream countries are characterized by smaller aquifers with connection to present day renewable groundwater recharge, the aquifers in the lower Nile segment are characterized by large storage with limited groundwater recharge, except along the Nile valley. The Eastern Nile basin is underlain by four major categories of aquifers. The basement rock aquifers occupy 30 % of the basin area, most of which is exposed in arid areas of Sudan and Egypt. The consolidated multilayered sedimentary rock aquifer covers 24% of the surface area of Eastern Nile basin but contain one of the most prolific aquifers with very big storage. The multilayered unconsolidated sediments, occupying 34% of the basin areas is the most exploited aquifer for irrigation water use in Sudan and Egypt. Volcanic rock aquifers cover 12% of the basin area, whereby 80% of the volcanic aquifers are confined within Ethiopia. More than 30 individual aquifers have been identified in the Nile Basin.