Gross Commanded Area (G.C.A) is the sum of culturable Commanded Area (C.C.A) and unculturable area. Again Culturable Commanded  Area (C.C.A) is divided into the sum of culturable cultivated and culturable uncultivated areas. Therefore, Gross Commanded Area (G.C.A) is a large quantity.

This type of area is not kept under cultivation because, to restore the fertility of the soil, to provide pasture land for animals, to prevent water logging in the land.

Assume that crop period is equal to base period. So, given base period is 168 days, and it requires watering for every 24 days. Therefore number of waterings for entire cultivation = (168/24) = 7                      Each watering needs 6 cm depth of water. So, therefore total depth of water reqires in 168 days = 7 × 6 = 42 cm

Assume that crop period is equal to base period. So, given base period is 168 days, and it requires watering for every 24 days. Therefore number of waterings for entire cultivation = (168/24) = 7                      Each watering needs 6 cm depth of water. So, therefore total depth of water reqires in 168 days = 7 × 6 = 42 cm

By lining of canals, carrying irrigation supplies we can reduce seepage and evaporation losses. Therefore reducing the field requirments of water increases the duty.