Water Resources and Their Utilization in India
▬ Water resources of India can be divided into two parts: (i) Surface Water Resources and (ii) Underground Water Resources.
Surface Water Resources
▬ According to the estimate, India receives an average of 109 cm of rainfall annually.
▬ This rainfall amounts to 37,000 million cubic metre. Out of this, 12,500 million cubic metres evaporates and another 7,900 million cubic metres is absorbed by land. Only 16,600 million cubic metres water is available in our rivers.
▬ Out of this, only 6,600 million cubic metres of water can be used for irrigation.
Underground Water Resources
▬ Out of total rainfall, only 7900 million cubic metres of water percolates inside/beneath the earth.
▬ Out of this, only 4300 million cubic metres of water is able to reach the upper layer of the soil.
▬ This water is more important for agricultural production.
▬ Rest 3600 million cubic metres reaches the impervious rocks which can be used by digging wells or tubewells. Out of this only 2250 million cubic metres of water is economically viable.
Sources of Irrigation in india
▬ There are various sources of irrigation which are:
(a) Wells & Tubewells 46% of total irrigation
(b) Canals 39% of total irrigation
(c) Tanks 8% of total irrigation
(d) Other Sources 7% of total irrigation (Dongs, Kuhls, Springs etc.)