Flooding

How is snow melt, relief and deforestation responsible for flooding?

And if possible, please also answer: Why do buildings on floodplains increase the likelihood of flooding?

Thanks

How is snow melt, relief and deforestation responsible for flooding?

And if possible, please also answer: Why do buildings on floodplains increase the likelihood of flooding?

Thanks

How is snow melt, relief and deforestation responsible for flooding?

And if possible, please also answer: Why do buildings on floodplains increase the likelihood of flooding?

Thanks