Question

Explain how deforestation leads to flooding of rivers

Answer 1

due to the process of deforestation flooding of rivers occur. 
this is because when deforestation occurs soil erosion takes place due to which the river beds get filled with sand causing flooding of rivers

Answer 2

When the trees are present, they bind the soil together.You must be knowing that trees only use 1% of absorbed water from soil in photosynthesis and release other 99% in transpiration. So when they are cut down, the excess water in the soil is not absorbed and these flow into the rivers causing heavy floods.

THE 2ND POINT HAS BEEN ALREADY MENTIONED BY MAISHA

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