Drought and climatic change impact on streamflow in small watersheds

The paper presents a comprehensive, thought simple, methodology, for forecasting the annual hydrological drought, based on meteorological drought indications available early during the hydrological year. The meteorological drought of 3, 6 and 9 months is estimated using the reconnaissance drought index (RDI), whereas the annual hydrological drought is represented by the streamflow drought index (SDI). Regression equations are derived between RDI and SDI, forecasting the level of hydrological drought for the entire year in real time. Further, using a wide range of scenarios representing possible climatic changes and drought events of varying severity, nomographs are devised for estimating the annual streamflow change. The Medbasin rainfall–runoff model is used to link meteorological data to streamflow. The later approach can be useful for developing preparedness plans to combat the consequences of drought and climate change. As a case study, the area of N. Peloponnese (Greece) was selected, incorporating several small river basins.

► Assessment of meteorological drought through the reconnaissance drought index.
► Assessment of hydrological drought through the streamflow drought index.
► Forecasting regression equations between RDI of 3, 6 and 9 months and annual SDI.
► Nomographs of streamflow change based on drought and climatic change scenarios.
► Assistance to authorities and stakeholders to mitigate drought consequences.