Strengthening flood and drought risk management tools for the lake Chad Basin

Lake Chad is extremely sensitive to climate variability because it is a shallow inland lake, and about 97.5% of its water supply depends on the Chari-Logone River System and other tributaries. Any increase or decrease in lake volume inflow means a substantial increase or decrease in lake area. Droughts in the Sahel Region and within the basin after the 1970s had great impact on discharges of different tributaries, which led to a drastic decrease of water inflow in the lake, as well as significant seasonal and inter-annual variation of the lake area over the last 50 years. Information gaps about the water system and uncertainties about climate variability and change remain a challenge. Hydrological extremes, both floods and droughts, present a threat to agriculture and water resource management within the Lake Chad Basin. Drought and flood monitoring over the basin is difficult because of the shortage of observational data, both historic and in real time. Satellite remote sensing and hydrological modelling are techniques used to compensate for the data collection shortcomings of the region. The Africa Flood and Drought Monitoring (AFDM) provides drought and flood monitoring, and short-term and seasonal forecasting that combine climate prediction, hydrological modelling and remote sensing data in the sub-Saharan African continent. For the Lake Chad Region, the system was adapted with higher resolution to provide near-real-time water levels, as well as short-term forecast of flood risks, as well as medium-term forecasts of drought hazards and long-term projections of climate change impacts. Preliminary results are very encouraging; the system will continue to be updated, tested and validated to enable its operational use by decision-makers at all levels.