Question

two reasons why the rivers of the Deccan Plateau are non-perennial and non navigable

Answer 1

The rivers of the Deccan Plateau are non- perennial because they depend only on rain for water and get dried up in summer due to absence of rain. The rivers are non navigable because they mainly flow through the hilly regions.

Answer 2

as the Deccan pleatue is formed due to volcanic errupton the land in this region is slightly up then other states as water reservoirs are mainly flow from east to west and met to Arabian sea that's why there are not perrenial . your second question is wrong because I live in Deccan pleatue region and here rivers or water risevoirs are navigable