Functions of njuri ncheke​

The functions of the Njuri-Ncheke are to make and execute community laws, to listen to and settle disputes, and to pass on community knowledge and norms across the generations in their role as the custodians of traditional culture. A lesser-known, yet important function of the Njuri-Ncheke, is overseeing and enforcing the rules and regulations controlling the use and conservation of open grasslands, salt-licks and forests. Their work as conservators extends to the preservation of sacred sites.

to find facts and details to use as evidence

dylan has written many enduring songs and he has received several awards for his musical achievement;  

any written work with artistic value can be considered literature; especially if such work is publicly recognized, and has had importance and endurance among people; whether is poetry or fiction or drama or even criticism, since it's the transcendence and representation of a culture, language or people in a period of time to more people, using letters (words), regardless the subject.

the nobel prize in literature is given to authors from any country based on a body of work as a whole that inspires and nurses the life of humanity.  

and the work of bob dylan matches that description, therefore is well deserved since he'd created new poetic expressions within the american song tradition, that has inspired and influenced the lives of many people, not only withing the united stated but worldwide as well.