Environment resources & its Utilization- 03
The rainfall variation is so huge that Mousinram near Cherrapunji in Meghalaya in the North-East receives about 11,690 mm rainfall while Jaisalmer in Rajasthan has only 150 mm of rainfall. About 75% of the rainfall is received in rainy season (June to September). As per an estimate around 21% of the area in the country receives less than 750 mm of rains annually while 15% has rainfall in excess of 1500 mm. Peninsular India receives rainfall less than 600 mm while western part of Rajasthan and Gujarat experience a rainfall less than 500 mm annually.
SURFACE WATER RESOURCES– are comprised of rivers and inland resources like lakes, ponds, canals etc. A large section of society is dependent on them as they provide livelihood and other ecosystem services. Of many rivers in India, 12 are classified as major rivers having total catchment area of about 252 mha. The Ganga – Brahmputra – Meghna system is having the largest catchment area of 110 mha (CWC, 2010). Other major rivers are- Indus, Godavari, Krishna and Mahanadi with a total catchment area of about 103 mha. The catchment area of medium rivers is about 25 mha.
India is one of the largest ground water consumers of the world with an estimated usage of 230 km3 per year (World Bank, 2010a). About 60% of the water demand in agriculture and 80% in domestic usage are met through groundwater. The National Sample Surveys (NSS) using remote sensing data suggest that as much as 75 to 80 % of the country’s irrigated area is served by groundwater wells (Shah, 2009).
CHALLENGES IN WATER UTILIZATION
The grave scenario
At a global level 70% Of Water Is Used For Agriculture about 25% For Industry And Only 5% For Domestic Use. However this varies in different countries and industrialized countries use a greater percentage for industry. India uses 90% for agriculture, 7% for industry and 3% for domestic use. One of the greatest challenges facing the world in this century is the need to rethink the overall management of water resources.