Question

Analyse the sketch map given below which shows two flood prone regions of India marked P and S.

Explain any four causes of floods in these regions.

Answer 1

The two flood-prone areas in India, designated P and S on the provided sketch map, are Assam and Bihar, respectively. Four factors contribute to flooding in these areas:

1. Himalayan Runoff: The Himalayan mountain range is downstream of both Bihar and Assam. The Himalayan region has high rainfall and snowmelt during the monsoon season, which causes rivers that flow into these states to swell dramatically and frequently overflow.
2. Monsoon Rains: There is a lot of rain during the monsoon season. Assam, which is situated in the Eastern Himalayan foothills, receives a lot of rain, and Bihar, which is on the Ganges plain, also gets a lot of rain during the monsoon season. Floods occur when the ground's capacity to absorb water is frequently exceeded.
3. Riverine Factors: Numerous rivers, such as the Ganges, Kosi Gandak, and Ghaghara, which draw water from the Himalayas and their tributaries, crisscross Bihar. In a similar vein, the Brahmaputra and its tributaries rule Assam. Riverbed siltation causes the riverbeds to rise, which causes spillovers during periods of intense precipitation.
4. Deforestation: Deforestation in the catchment areas has decreased soil absorption of water in both states, increasing surface runoff into rivers. Such deforestation in the Himalayan foothills has also resulted in landslides, which increase the risk of flooding by obstructing waterways and causing abrupt releases of water. These elements increase the susceptibility of these areas to flooding, as does human activity such as haphazard urban growth and inadequate flood control infrastructure.