Bs Reporter / New Delhi August 27, 2008, 5:53 IST Bihar Chief Minister Nitish Kumar will visit New Delhi to meet Prime Minister Manmohan Singh tomorrow to ask for help to deal with what he terms "a catastrophe.' The chief minister, who is also the disaster management minister of the state, has asked that the two-km breach in the embankment on the Kosi river should not be termed a "mere flood.' "It is a catastrophe, an unprecedented disaster for Bihar,' he said. The Kosi river, which over the last 250 years has moved its course from east to west by over 120 km, suddenly covered the same distance westwards when it breached its embankments in Bhimnagar in Bihar and Nepal. This has resulted in death of 45 people and displacement of thousands. The border di stricts of Araria, Madhepura,Purnea and Supaul