From the article: > geologists say the river disappearance is due to large cracks in the karstic riverbed, which empty the river underground like a siphon. It

From the article: > geologists say the river disappearance is due to large cracks in the karstic riverbed, which empty the river underground like a siphon. It is perhaps the important spring floods that washed away the sediment patches that blocked the holes and fissures.