WATER RESOURCES AND AGRICULTURE IN WESTERN INDIA
Impact assessment of climate change on water resources and agriculture to guide optimal reservoir operation and best crop management practices
Rajasthan is the largest state of India with 10.4% of the country’s area and 5.5% of its population, but only about 1% of the country’s water resources producing 5.49% of the nation’s total food grains and 21.31% of its oil seeds. The Bisalpur dam project plays an important role in the economy of the western Rajasthan region of the Banas river basin providing water for drinking to various cities and irrigation in the Tonk district. However, the present water resources of this region are not enough to cater to the needs of the increasing population, including agriculture and non- agriculture demands and climate change will act as an additional stressor. Thus, it is vital to assess the effects of climate change in order to have optimal reservoir operation and adapt to best crop management practices.
CASE STUDY DESCRIPTION
Issue to be addressed
The Banas River Basin is the largest river basin (45833 km2) within the Rajasthan State of India. Banas is a seasonal river that dries up during the summer, but it is nonetheless used for irrigation. Bisalpur drinking water cum irrigation project is constructed across river Banas with an ultimate irrigation potential of 55224 hectare (irrigation during the months of October to March for the Rabi crop), besides providing 458.36 million m3 of drinking water for Jaipur, Ajmer, Beawar, Kishangarh, Nasirabad and other enroute cities, towns and villages. An estimated 150 million USD of extra agriculture was produced in 2014-2015. An increase in temperature in this region has been observed from historical data. This may lead to shortening of the crop growth period, increase in crop water requirement and reduction in crop yield. The water availability in this reservoir in coming years will play a crucial role in the overall economy of the entire region including other socio-economic issues.
Decision support to client
The government of Rajasthan recognised the water resources and agriculture vulnerability being in the state with one of the lowest adaptive capacity which makes immediate action on climate change crucial. The Rajasthan State Action Plan on Climate Change (under Prime Minister Council on Climate Change) proposes many strategies for state mission on rater resources and agriculture among other sectors. The methods and results generated in the present study will help the clients namely, Water Resources Department and Agriculture Department of Rajasthan State in their actions like: (i) Setting up dedicated facilities with advanced computing systems and customize information on impacts of climate change for regional water basins/sub basins/watersheds; (ii) Conducting training programs for government officials to facilitate the understanding of the impacts of climate change on water resources and familiarize them with modelling outputs and its significance for decision making; (iii) Educating farmers about matching land-use systems with water availability by adopting water efficient practices and low water requiring crops for agriculture, etc. Moreover, all the information produced within this study will be open source which will prove to be useful for other socio-economic sectors in terms of climate change awareness.
Temporal and spatial scale
The results of this case study will help decision making at a local/regional scale (approximately 40 000 km2 including Banas catchment upto Bisalpur dam and the downstream irrigation command area). The adaptation measures will be implemented over 20 years period.
Field visits have been made to interact with clients and other stakeholders including farmers. We have presented the objectives of the project to clients and taken their feedback on the type of CIIs that will help them in their decision making of reservoir operation and crop management practices. The clients are sharing field data required for hydrological modelling and bias correction. More field visits will be taken up during the course of the project for taking client’s feedback on the usefulness of the form of study results and modifications in the format of results to make them more generalized and useful for decision support.