Hungary lies within the drainage basin of the Danube, which is the longest river in the country. The Danube and two of its tributaries, the Rába and Dráva rivers, are of Alpine origin, while the Tisza River and its tributaries, which drain much of eastern Hungary, rise in the Carpathian Mountains to the east. The Danube floods twice a year, first in early spring and again in early summer. During these phases, discharge is up to 10 times greater than river levels recorded during the low-water periods of autumn and winter. The Tisza forms a floodplain as it flows through ...(100 of 37110 words)