NEW DELHI, July 29 (AFP) - Indian Booker-prize winning author  
Arundhati Roy will be the celebrity focus of a mass "rally in the 
valley" protest this week against a major dam project in western 
India. 
   Winner of the 1997 Booker Prize for her Novel "The God of Small  
Things," Roy has since turned her writing talents to polemical 
tracts against India's nuclear tests and the construction of the 
Narmada Dam. 
   Roy was due to leave New Delhi late Thursday along with a large  
group of environmental activists, artists and journalists, to join a 
four-day rally through areas of the Narmada River valley that will 
be submerged by the proposed dam. 
   Critics of the seven-billion-dollar project, which straddles the  
states of Gujarat, Madhya Pradesh and Maharashtra, argue that the 
dam's benefits in no way justify its expense and point to the 
500,000 people who will be displaced in the submergence area. 
   Supporters insist that the power generating capacity is crucial  
to developing the impoverished region. 
   Opposition to the dam has existed since its inception 15 years  
ago, but Roy's participation has helped generate enormous publicity 
for the issue. 
   The dispute is an emotive one and copies of Roy's short book --  
"The Greater Common Good" in which she sets out her argument against 
the dam -- have been publicly burned in places like the Gujarati 
capital, Ahmedabad. 
   Roy, who has labelled the dam "a medieval nightmare," said the  
fame that accompanied her Booker Prize was one of the factors behind 
her new-found activism. 
   "After the tremendous commercial success of my book, I felt that  
to remain human I had to go back to the land where "The God of Small 
Things" came from, back to the villages," she said. 
   Describing large dams as "massive, obselete, human-crunching,  
money-guzzling, technological disasters," Roy said the human cost of 
the Narmada project was incalculable. 
   "It is like destroying a civilisation and spitting in its face  
while you're about it," she said. 
   In February the Supreme Court lifted a four-year stay on the  
dam's construction.