Q- Why do the north-east trade winds change their direction while blowing through the Ganga valley?
Answer- The north-east trade winds change their direction while blowing through the Ganga valley because of the following reasons:
1. A feeble high pressure area develops over the north-western part of India in the cold weather season. Light winds begin to blow outwards.
2. The direction of the north-easterlies changes as a result of this contact as well as under the influence of topography.
3. The dry north-westerlies winds comes in contact while the Indian trades (north-easterlies) over the Ganga valley.
4. The directions in north-westerlies down the Ganga valley and northerlies over the Ganga Brahmaputra delta.
5. Over the Bay of Bengal, the trade winds retains their original north-easterlies directions, as they are free from the influences of any topography over the sea.