Impact+of+human+activities+on+catchments+and+flooding+in+Bangladesh

Impact of human activities on catchments and flooding in Bangladesh.

What is A Catchment? A catchment is the land area from which a river or reservoir is fed, also known as a drainage basin or watershed.
 * Flooding**
 * Flooding in Bangladesh: 5 Main causes.**
 * About 80% of bangladesh consists of the flat low-lying flood plane and deltas of the rivers ganges, Brahmuptraand Megna.
 * **Majour Monsoon** occurs in South East Asia. summer monsoon responsible for excessive rainfall in Bangladesh
 * Not known if the **heavy precipitation** is an effect of other reasons such as deforestation or the Greenhouse effect.
 * **Himalayas** are one of the few places in the world that retain **permanent glaciers**. the glacial ice melts causing increases in melt water flowing through the drainage basins, increasing channel flow, saturating soils and causing massive overland flows.
 * **Deforestation**- attributed to removal of trees in the forest of Nepal and himalayan areas. Population increase meant more deforestation in hills of Nepal. steep slopes led to accelerated soil erosion and landslides during the monsoonal precipitation which contributes to devastating floods.
 * **Failed river management** - Bangladesh Government carried out flood action plan where **embankments** were put along the banks of the main rivers. this worked but not for long... it wasn't designed to cope with the amount of water in the 1987-8 floods. The water **breached** the embankment and caused **widespread flooding**
 * **Excessive development** - Rapid population growth creates extra pressure on the land of already crowded bangladesh.
 * Ag land gives way for houses and roads. **Urbanization** aggravates flooding problem.
 * Floods are now almost **6 times more numerous**.