Dr. Banarsi Lal
Nationally and internationally, 2023 is an important year for the water-related goals. The United Nations (UN) adopted a resolution in 2017, declaring 2018-28 as the International Decade for Action on Water for Sustainable Development. Water is an important resource for the development of any society and is helpful to maintain the integrity of the ecosystems. It is a critical resource for the growth of any economy. Water management is very essential to get the food security and prevent the soil erosion. It has been observed that demand of water has been increased almost eightfold in the last 100 years. There is availability of about 1,400 Million Cu. Kilomteres of water in the world but only 0.003 per cent of this can be used for the hygiene, drinking, agriculture and industry. But all this water is not accessible because part of it flows through in to the rivers during the seasonal floods. The average annual rainfall overland is 1, 10,000 Km3, but about 70,000 km3 evaporate before reaching to the sea. The remaining 40,000 km3 is available for human use but two-thirds of it run off in floods. About 60 per cent area in India is still rain fed so the monsoon rains play a significant role in India. Global population is increasing at an alarming rate whereas the natural resources such as land and water are static. The world may face 40 per cent shortfall between forecast demand and available supply of water by 2030.It has been observed that the global water withdrawal grew 1.7 times faster than the population. Climate change may worsen the situation by increasing the frequency and intensity of floods and droughts, making water more unpredictable by altering hydrological cycles.
About 80 per cent of land is rain fed in the world and this land contributes about 60 per cent of food production. Rest 20 per cent comes under irrigated agriculture which contributes about 40 per cent of food production. It brings the self-sufficiency in the developing nations across the globe. The complexity of problems in rain fed agriculture is greater than that of irrigated agriculture. In India about 127 million ha cultivable land comes under rain fed condition which is approximately 70 per cent of the total cultivated land. Agriculture is the largest consumer of freshwater and during the last 30 years food production has been increased by 100 per cent. Over 1 billion people across the world are involved in agriculture. And they generate about $ 2.4 trillion in economic every year. Thus the importance of rainwater harvesting is increasing over the years. In India huge amount of budget is being invested on rainwater harvesting to mitigate the climate risks. Cost-effective technologies and an in depth analysis on rain water management are needed for the sustainable agriculture. There is need to adopt alternative food crops and irrigation practices for sustainable agriculture. Millets can be promoted under rain fed agricultural system as they can be grown with less water. Rainwater is recognized as the viable alternative to mitigate the demand of washing, sanitation and crop irrigation. It is also helpful to mitigate the demand of droughts. It will give the food security and reduce the impact on humans and environment. During rainfall 70 per cent of annual ground water is contributed by the states such as Kerala, Madhya Pradesh, Mizoram, Meghalya, Gujarat etc. There is 61 per cent contribution of recharge rainfall both from the monsoon and non-monsoon to the country’s to the country’s total annual groundwater and the remaining 39 per cent recharge comes from other sources such as recharge from tanks, canal seepage, ponds and water conservation structures.
Monsoon plays a significant role in the Indian agriculture as the major sown part of the country is still rain fed. The summer monsoon accounts for 70 to 80 per cent of the annual rainfall over the major parts of the South Asia. Timely rainfall is important for the Kharif season crops. Coastal areas of the country such as Tamil Nadu receive the much of the rainfall from the North-East Monsoons, between October and December. Average rainfall in India is 1183 mm out of which 75 per cent is received during the monsoon period i.e.July to September. This results runoffs during the monsoon period and thus there is need to work on the rain water harvesting so as to save the water for the rest of the year. If even 5 per cent of water is harvested, it would produce a substantial quantum of water to the tune of 900 million litres. Due to lack of storage infrastructure, and storage procedure only about 18-20 per cent of water is used. Thus, rainwater harvesting is very important. It is expected that about 24 million hectares of rainwater can be harvested by making the small structures for water harvesting. If monsoon water is properly harvested, 30 per cent of it can be harnessed for the Rabi season crops. About one tone of yield can be supplemented by utilizing the rain water. The remaining 70 per cent of the harvested water can be will help in recharging the groundwater aquifers which may help to raise the groundwater level by 2 metres. Our agricultural system is mainly depending on monsoon because we are growing water loving crops such as paddy and sugarcane. We need to grow less water loving crops such as pulses and oilseeds so that we can counter the erratic monsoons. With new innovations we can conserve the rainwater and ensure the bright future for our environment and crop production. Such as we can utilize the artificial intelligence in agriculture that can optimize the water usage. Rainwater harvesting can be very handy to increase the declining water levels. The surface runoffs can be utilized efficiently. It can reduce floods on roads and roundabouts. Rainwater is simple, eco-friendly and economical.
Farmers use their own indigenous techniques to harvest rainwater. These innovations are helpful to mitigate their water needs. It is estimated that for every square foot of imperious surface, a one-inch rainfall will collect 0.623 gallons of water. We can harvest the rainwater at our rooftops of our houses. Rainwater is salt free and slightly acidic and plants can be grown with slightly acidic water. In India, different types of water harvesting structures are innovated, designed and used across the nation since old times. Through these techniques water is harvested by making small structures. These structures support the landscape and maintain biodiversity. These structures help to maintain the green cover and maintain flora and fauna in the environment. But with the passage of time these structures have become obsolete and their revival is needed. The govt. has taken several initiatives to manage the country’s groundwater resources. These initiatives include formulation of master plan for artificial recharge to groundwater, circulation of a model bill to all the states/UTs and Implementation of the National Aquifer Mapping and Mangement Programme to map major aquifers. The other initiatives such as Har Khet Ko Pani, Pardhan Mantri Sinchayi Yojna, Atal Bhujal Yojana etc. focus on improving the ground water. Jal Shakti Abhiyan was launched in 2019 in 1592 blocks of the country. It is an innovative scheme focusing on the water conservation and water harvesting. Community based water management approach is needed. The focus should be given on the water reuse and recycling technologies. Smart water management system can help us to improve the reliability of water supply, reduce wastage of water and minimize the costs on water. The message of water conservation should be communicated at all levels through the information, education and communication so that challenge of water scarcity can be mitigated.
The writer is Sr. Scientist & Head of KVK, Reasi, (SKUAST-J).
