Risk Assessment at the Beginning and the End of Strouma River in Bulgaria Using Integral Indices

The present work considers Strouma River on the Bulgarian territory using the integral method for evaluation of climatic and anthropogenic impacts on the average annual water volume and maximum and minimum water flow. The level of this impact and risk assessment is determined by the index Mmax, i for the deviation of the maximum water flow from the maximum flow norm Qmax, 0 and the index Mmin, i for the deviation of the minimum water flow from the minimum flow norm Qmin, 0. Using the dynamics of the integral indices Mmax, i, Mmin, i and information on extreme events from the past, a preliminary risk assessment of future extreme events such as floods and draughts could be made. This is done for the first time in risk assessment of extreme events and has been checked at Pernik (in the beginning) and Marino pole (at the border in Greece) for the period 1948 - 2006.