The importance of irrigation to help agriculture was recognised in India from
the earliest times, for all parts of India were not liberally and equally watered
by rivers and rainfall. The north-western part of India especially needed
irrigation, which was done by various means. Canals were constructed to
prevent inundation as well as to irrigate dry areas. According to Narada, there
were two kinds of dykes—the bardhya which protected the field from floods
and the khaya which served the purpose of irrigation. The canals which were
meant to prevent inundation were also mentioned by Amarasimha as
jalanirgamah (drains). Canals were constructed not only from rivers but also
tanks and lakes. The tanks were variously called, according to their sizes, as
the vapi, tadaga, and dirghula. Of the lakes, the most famous was the
Sudarsana lake at the foot of the Girnar Hills in Gujarat. Wells were also used
for irrigation of small plots of land. Brihaspati informs us that fines were
imposed on those who did any mischief to the irrigation works.
Kalidasa provides an elaborate account of forests and forest produce of the
Gupta period. The forests yielded a variety of products, such as timber for
buildings, boats and ships, skins of various wild animals, ivory, musk, lac and
yak tail. That the forests were considered a source of considerable wealth is
testified to by the appointment of a royal official as the superintendent of
forests, known as gaulmika.
Mining and Metallurgy
Among the various industries that flourished in the Gupta period, mining and
metallurgy certainly occupied the top position. Amarasimha, Varahamihira
and Kalidasa make frequent mention of the existence of mines. From their
accounts, it is quite evident that the mines of the Kushana period were
continued to be worked in the        Guptas period as well. The Amarakosa of