Lessons from LAKES

Lake-level fluctuations have large impacts on society. Social tensions have deen reported for various lakes facing drought (e.g. Lake Chad, Lake Chilwa, Lake Tai and Lake Urmia).

However, the sensitivity of lake hydrology to human drivers is poorly understood. An example is the recent hydrological phenomenon in the Kenyan Rift Valley (KRV) system: dramatic declines of lake levels – lowest observed in six decades – were followed by substantial increases – highest levels in three decades. Although such fluctuations are normally attributed to seasonal variations in rainfall, climate is only one among other drivers. Assessing the extent to which human influence amplifies or mitigates the effect of climate remains a scientific challenge that should be addressed by socio-hydrological approaches. Therefore, the objective this study will be to quantify the relative contributions of both natural and human drivers on lake water balances. Lakes are particularly relevant as they provide important ecosystem services and they often provide data that represent outflow of catchments in addition to often limitedly-available streamflow data. Building on an improved understanding obtained from the KRV lakes the assessment will be expanded to select global lakes of international importance. This will ultimately result in the developing a framework for spatiotemporal-explicit assessment of the relative contributions of natural and human drivers of lake level fluctuations worldwide.