Several great floods were recorded in the Tisa river basin in the XX century. 17 people died and 4 thousand houses were destroyed as the result of the flood in 1992. Scientists think that recurrence of natural disasters in this region every 4-7 years is connected with solar activity. It is easy to forecast that the flood will recur in 2002-2004. Storm rainfalls is the main but not the only reason of floods in the Transcarpathian region.
Rainfall overflowing mountain streams promotes mudflows hazard.
Water, saturated with particles, transforms into a sediment flow, its velocity increases and correspondingly its destructive strength increases too. Mudflows can occur in all mountain streams and rivers in the Carpathians. Potential mudflow danger increases with environmental deterioration of river beds and watersheds. There was a case when builders forgot to remove a pier in an inflow of the Black Tisa river. The pier blocked the river bed and formed a dam during the flood of 1992.