Climate variability and water resources management in Lake Chad Basin: Integrating science and policy

Abstract:

The challenges of water resources management in the Lake Chad (LC) region are multifaceted. At the regional scale, the frequent severe drought in the Sahel region - of which LC is part - has been attributed to the complexity in atmospheric dynamics that control precipitation. Locally, the pressure of human needs for water resources compounds the problem. Climatic and anthropogenic factors were thus analyzed in this study to understand the drivers of LC variability. The period between late 1960s and early 1970 marked a turning point in the response of LC level to precipitation and remote climatic drivers in the region. The drop in the size of LC level from 283 meters in early 1960s to about 278 meters around 1983/84 was the largest to occur in the period of study and coincides with the combined cold phase of Atlantic Multi-decadal Oscillation (AMO) and strong El Nina phase of ENSO. An overlay analysis integrating population and biomass burning footprint was used to identify anthropogenic hotspots that are likely to define the modification of the LCB in the future. Analysis of anthropogenic dynamics suggests that with a projected population of 51 million in 2015 rising to about 80 million by 2030, the LC watershed will be significantly impacted. The spatial characteristic of the anthropogenic footprint show that sustaining water services will continue to be a problem. The anthropogenic hotspot map generated is thus a useful tool for policy makers to target areas of rapid change with the greatest impact on the size of LC. The proposed inter-basin water transfer will require the most comprehensive urgent policy responses. A reversal of the shrinking of LC by this transfer presents a 'bright spot' that can prevent the worsening socio-economic crisis from reaching a flashpoint.