Predictive modelling of groundwater flow of Indira Gandhi Nahar Pariyojna, Stage I

Abstract

A MODFLOW (Modular Groundwater Flow Model)–based mathematical groundwater flow model was developed for the part of Indira Gandhi Nahar Pariyojna (IGNP) Stage I area falling in Hanumangarh and Sriganganagar districts of Rajasthan, India. This region is facing severe problems of waterlogging and salinity. The developed groundwater model has been used to evaluate different strategies to arrest waterlogging and to predict future water table distribution in the study area. Four different water use management strategies have been considered, including one presently followed to compare output of the other three strategies being considered. Other strategies are as follows: strategy second, with groundwater development of 18% of canal water; third, with reducing water allowance in IGNP command from 0.36 litre/sec/ha. to 0.241 litre/sec/ha and construction of a proposed surface drain; and fourth, the same as the third but in addition to diverting Ghaggar flood waters, keeping 18 depressions dry and repairing the damaged lining of RD (reduced distance [1000']) 0-100 of Indira Gandhi Mukhya Nahar (IGMN) in order to reduce canal seepage. On the basis of these strategies, four scenarios were developed. The output in the three scenarios has been compared for the addition to the groundwater storage and area waterlogged after 12 years (2003–2015). This addition to groundwater storage in 12 years as per scenarios II, III and IV comes to 1079.41, 1403.97 and 605.68 MCM, respectively, as compared to scenario I, where the total addition comes to 1663.43 MCM. Waterlogged area in category 1 with water table up to 1 m below ground level (mbgl) as per scenarios I, II, III and IV comes to 19,289.5, 12,746.6, 14,433.8 and 4139.2 ha, respectively.