Question

how over mining and irrigation lead to land degradation​

Answer 1

over irrigation has a bad effect environment and it leads to degradation because of the water logging which leads increase in salinity in soil and over mining also has a bad effect .Due to overmining forests are cleared and huge pits dug to extract minerals which causes soil erosion ,and also lead to degradation

Answer 2

Mining creates lots of dust, this dust when disposed on land pollutes it and creates land degradation.

Over irrigation also causes land degradation due to water logging which increases the salinity and alkalinity of the soil.

Hope This Is Helpful !