Ganges Aquifer Management in the context of Monsoon Runoff Conservation for Sustainable River Ecosystem Services – A Pilot Study

Abstract

The study area comprises of Sot river catchment. The Sot river is a tributary of the Ganga river. The Sot river flows in between the Ganga and the Ramganga river. Though both these rivers have good water potential, the Sot river is drying-up after the monsoon season in recent years, and its catchment is facing acute water problem and many hydrological problems, including deep groundwater levels, recurrent droughts, soil erosion and desertification in some areas. These factors coupled with the threat of climate change may aggravate crop losses in the area and poor health of river ecosystem. The catchment area falls in districts of JP Nagar, Moradabad, Budaun, Shahjahanpur and Farrukhabad. The Sot river, earlier used to be perennial, has now become a seasonal river. The geographical area of the Sot river catchment is 3,752.73 sq.km. The elevation of catchment varies from 138 to 245 m above mean sea level. The catchment receives an average annual rainfall of 882 mm, with very hot summer and cold winter. During summers, temperature normally varies from 30 °C to 43 °C and during winters from 5 °C to 25 °C. Average groundwater level varies from 0.90-26.2 mbgl during pre-monsoon and 0.3-25.9 mbgl during post-monsoon. Groundwater levels are shallow in the lower catchment and deep in the middle part of catchment. Groundwater levels are found declining during the period of investigation from 2009 to 2018. Groundwater fluctuation up to 14.85 m is found in the lower part of the catchment. Literature survey was done and various thematic maps, such as catchment boundary, catchment location, DEM, drainage, slope, soil, sub-basin, district/tehsil/road network, grid and land use, were prepared. Daily river flow data was collected and processed to analyse variations along with rainfall. Changes in land use and meteorological variables were also assessed. Infiltration and hydraulic conductivity tests were conducted at 48 locations in the entire catchment. The soil infiltration and conductivity were found to vary from 0.3 to 51.5 cm/hr and 0.05 to 2.3 m/d, respectively. Disturbed and undisturbed soil samples were collected from the same 48 locations of the catchment for the determination of soil properties. Forty-nine litho logs of underground formations were analysed and geological sections and fence diagram were developed to find aquifers geometry which indicate that the alluvial formations are in alternate layers of aquifers and aquitards. ANN model was applied to model the river flow for the period 2009 to 2016.